Cardiac resynchronization therapy with His bundle pacing as a method of treatment of chronic heart failure in patients with permanent atrial fibrillation and left bundle branch block.

PubMed

Boczar, Krzysztof; Sławuta, Agnieszka; Ząbek, Andrzej; Dębski, Maciej; Gajek, Jacek; Lelakowski, Jacek; Małecka, Barbara

CRT is a therapeutic option for patients with heart failure, sinus rhythm, prolonged QRS complex duration and reduced ejection fraction. We present a case of 71-year-old woman with dilated cardiomyopathy, NYHA functional class III and AF. We implanted CRT combined with direct His-bundle pacing. The indication for such a therapy was a left bundle branch block with a QRS complex of 178ms and a left ventricular EF of 15%, left ventricular end-diastolic diameter (LVEDD) of 75mm. After 8months of follow-up the LVEDD was 60mm with EF 35-40%. Copyright © 2017. Published by Elsevier Inc.

[Intervention among patients with right bundle branch block and left anterior hemiblock. Operatory risk (author's transl)].

PubMed

Coriat, P; Harari, A; Tarot, J P; Ducardonnet, A; Viars, P

1981-01-01

In order to assess the risk of advanced heart block during anesthesia in patients with right bundle branch block and left anterior hemiblock, 35 consecutive patients were monitored throughout the pre-, intra- and postoperative period. As conventional ECG monitoring may only detect advanced atrioventricular block, patients were monitored according to the Holter method which can easily detect even minor changes of atrioventricular conduction namely slight increased PR interval or dropped P wave. All patients were asymptomatic, in normal sinus rhythm without second degree AV block. Surgical procedures were performed under general anesthesia (n = 15) and epidural anesthesia using lidocaine (n = 20). No episode of second or third degree atrioventricular block occurred. The only modifications observed were rare and transient increase of PR, occurring during surgical procedures in 5 patients, always associated with a sinus bradycardia. They immediately regressed at the termination of the sinus bradycardia either spontaneously or following atropine injection, strongly suggesting the responsability of increased vagal tone. Thus general or epidural anesthesia did not compromise infranodal conduction in any of the observed patients. These data indicate that anesthesia can be safely used without prophylactic preoperative insertion of pacemakers in patients with asymptomatic chronic right bundle branch block and left anterior hemi-block.

Experimental, Pathologic, and Clinical Findings of Radiofrequency Catheter Ablation of Para-Hisian Region From the Right Ventricle in Dogs and Humans.

PubMed

Xue, Yumei; Zhan, Xianzhang; Wu, Shulin; Wang, Hongyue; Liu, Yang; Liao, Zili; Deng, Hai; Duan, Xuejing; Zeng, Shaoying; Liang, Dongpo; Elvan, Arif; Fang, Xianhong; Liao, Hongtao; Ramdat Misier, Anand R; Smit, Jaap Jan J; Metzner, Andreas; Heeger, Christian-Hendrik; Liu, Fangzhou; Wang, Feng; Zhang, Zhiwei; Kuck, Karl-Heinz; Yen Ho, Siew; Ouyang, Feifan

2017-06-01

Ablation of para-Hisian accessory pathway (AP) poses high risks of atrioventricular block. We developed a pacing technique to differentiate the near-field (NF) from far-field His activations to avoid the complication. Three-dimensional mapping of the right ventricle was performed in 15 mongrel dogs and 23 patients with para-Hisian AP. Using different pacing outputs, the NF- and far-field His activation was identified on the ventricular aspect. Radiofrequency application was delivered at the NF His site in 8 (group 1) and the far-field His site in 7 dogs (group 2), followed by pathologic examination after 14 days. NF His activation was captured with 5 mA/1 ms in 10 and 10 mA/1 ms in 5 dogs. In group 1, radiofrequency delivery resulted in complete atrioventricular block in 3, right bundle branch block with HV (His-to-ventricular) interval prolongation in 1, and only right bundle branch block in 2 dogs, whereas no changes occurred in group 2. Pathologic examination in group-1 dogs showed complete or partial necrosis of the His bundle in 4 and complete necrosis of the right bundle branch in 5 dogs. In group 2, partial necrosis in the right bundle branch was found only in 1 dog. Using this pacing technique, the APs were 5.7±1.2 mm away from the His bundle located superiorly in 20 or inferiorly in 3 patients. All APs were successfully eliminated with 1 to 3 radiofrequency applications. No complications and recurrence occurred during a follow-up of 11.8±1.4 months. Differentiating the NF His from far-field His activations led to a high ablation success without atrioventricular block in para-Hisian AP patients. © 2017 American Heart Association, Inc.

False-positive defects on exercise 99mTc-sestamibi SPECT imaging, but not on dipyridamole 99mTc-sestamibi SPECT imaging, in a patient with right bundle branch block (RBBB).

PubMed

Javadi, Hamid; Jallalat, Sara; Semnani, Shahriar; Mogharrabi, Mehdi; Nabipour, Iraj; Abbaszadeh, Moloud; Assadi, Majid

2013-01-01

False-positive findings with myocardial perfusion imaging (MPI) have frequently been identified in the presence of left bundle branch block (LBBB) and tend to lower the accuracy of MPI in individuals with normal coronary angiographs. Pharmacologic stress is recognized as the preferred method for MPI in patients with LBBB. In contrast, very few studies have evaluated the effect of right bundle branch block (RBBB) on MPI, and there is no consensus regarding the selection of pharmacologic versus exercise stress during MPI for the RBBB patient. In this study, we present a 45-year-old man with RBBB, who has a normal coronary artery angiography, but who showed abnormal myocardial perfusion with exercise MPI, and normal perfusion on dipyridamole MPI. The aim of the study is to stimulate awareness that the stress method selected for patients with RBBB can potentially interfere with the accuracy of the data.

Mechanical dispersion is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks.

PubMed

Stankovic, Ivan; Janicijevic, Aleksandra; Dimic, Aleksandra; Stefanovic, Milica; Vidakovic, Radosav; Putnikovic, Biljana; Neskovic, Aleksandar N

2018-03-01

Bundle branch blocks (BBB)-related mechanical dyssynchrony and dispersion may improve patient selection for device therapy, but their effect on the natural history of this patient population is unknown. A total of 155 patients with LVEF ≤ 35% and BBB, not treated with device therapy, were included. Mechanical dyssynchrony was defined as the presence of either septal flash or apical rocking. Contraction duration was assessed as time interval from the electrocardiographic R-(Q-)wave to peak longitudinal strain in each of 17 left ventricular segments. Mechanical dispersion was defined as either the standard deviation of all time intervals (dispersion SD ) or as the difference between the longest and shortest time intervals (dispersion delta ). Patients were followed for cardiac mortality during a median period of 33 months. Mechanical dyssynchrony was not associated with survival. More pronounced mechanical dispersion delta was found in patients with dyssynchrony than in those without. In the multivariate regression analysis, patients' functional class, diabetes mellitus and dispersion delta were independently associated with mortality. Mechanical dispersion, but not dyssynchrony, was independently associated with mortality and it may be useful for risk stratification of patients with heart failure (HF) and BBB. Key Messages Mechanical dispersion, measured by strain echocardiography, is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks. Mechanical dispersion may be useful for risk stratification of patients with heart failure and bundle branch blocks.

SHERLOCK 3CG™ Diamond Tip Confirmation System

ClinicalTrials.gov

2018-05-15

Indication for Peripheral Intravenous Catheterization; Atrial Flutter; Premature Atrial Contraction; Premature Ventricular Contraction; Premature Junctional Contraction; Tachycardia; Atrioventricular Block; Bundle-Branch Block

Complete atrioventricular block following mediastinal irradiation: A report of six cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slama, M.S.; Le Guludec, D.; Sebag, C.

1991-07-01

Complete atrioventricular block (AVB) following radiotherapy has been reported rarely, usually after high dose mediastinal irradiation for Hodgkin's disease or lung or breast carcinoma. The authors report six new cases of episodic complete infranodal AVB, requiring permanent pacemaker implantation. The mean age was 48-years old (ranging from 25-60) at the first Adams Stokes attack, mean delay was 12 years after irradiation (10-18), and mean radiation dose was 5,200 rads (4,000-6,500). All patients had abnormal interval electrocardiograms (right bundle branch block in two, left bundle branch block in three, alternating left and right bundle branch block in one). Electrocardiograms during themore » episode of AVB or Holter recordings were consistent with infranodal block in all patients; electrophysiological study performed in five patients confirmed infranodal AVB in four, and one was normal. Pericardial disease was constant, which included pericardial constriction in four patients. Two patients died after failure of pericardiectomy to improve congestive heart failure, due to epicardial, myocardial, and endocardial involvement. Noncardiac mediastinal lesions were present in four cases. Since this delayed complication may occur in patients of such age that the relation between the AVB and the chest irradiation is questionable, they propose the following etiologic criteria; high radiation dose (over 4,000 rads); delay of 10 years or more; abnormal interval tracings; pericardial involvement; and associated cardiac or mediastinal radiation-induced lesions.« less

Dilated cardiomyopathy and left bundle branch block associated with ingestion of colloidal gold and silver is reversed by British antiLewisite and vitamin E: The potential toxicity of metals used as health supplements

PubMed Central

Archer, Stephen Lawrence

2008-01-01

A case of left bundle branch block and a dilated, nonhypertrophic cardiomyopathy associated with ingestion of colloidal gold and silver as an ‘energy tonic’ is described. The cardiac disease was reversed within two months by a course of dimercaprol (Akorn Inc, USA) (British antiLewisite) and vitamin E. This is the first case of gold and silver cardiomyopathy in humans, and highlights the risks of these colloidal metal ‘health supplements’. PMID:18464946

Heparan sulfate storage in the cardiac conduction system triggers atrioventricular block.

PubMed

Kato, Rie; Miyahara, Hiroaki; Kawano, Tatsuya; Matsuzuka, Atsuko; Noda, Kimiko; Izumi, Tatsuro

2017-05-01

To elucidate the novel biological functions of heparan sulfate (HS) by clinic-pathologically studying a patient with paroxysmal atrioventricular (AV) block. A long-surviving male patient with Sanfilippo syndrome type A presented with paroxysmal AV block at age 33years. He then survived another 2.5years after the onset of paroxysmal AV block and pacemaker implantation. His cardiac histopathological examination at autopsy showed HS storage in the cardiac conduction system (CCS), especially in the atrioventricular node (AVN)-His bundle branches. HS storage in the CCS might trigger AV block, arising from below the AVN-His bundle branches. This is the first description to indicate that HS might be an essential constituent of life-long CCS plasticity and that its storage in the CCS results in AV block. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

[Intermittent left bundle branch block - reversal to normal conduction during general anesthesia].

PubMed

Silva, Ana Maria Oliveira Correia da; Silva, Emília Alexandra Gaspar Lima da

Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value). This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Earlier Right Ventricular Pacing in Cardiac Resynchronization Therapy for a Patient with Right Axis Deviation.

PubMed

Hattori, Yusuke; Ishibashi, Kohei; Noda, Takashi; Okamura, Hideo; Kanzaki, Hideaki; Anzai, Toshihisa; Yasuda, Satoshi; Kusano, Kengo

2017-09-01

We describe the case of a 37-year-old woman who presented with complete right bundle branch block and right axis deviation. She was admitted to our hospital due to severe heart failure and was dependent on inotropic agents. Cardiac resynchronization therapy was initiated but did not improve her condition. After the optimization of the pacing timing, we performed earlier right ventricular pacing, which led to an improvement of her heart failure. Earlier right ventricular pacing should be considered in patients with complete right bundle branch block and right axis deviation when cardiac resynchronization therapy is not effective.

Cardiac arrhythmia induced by interferon beta-1a.

PubMed

Kastalli, Sarrah; El Aïdli, Sihem; Mourali, Sami; Zaïem, Ahmed; Daghfous, Riadh; Lakhal, Mohamed

2012-04-01

Cardiac adverse effects have never been reported with interferon (INF) beta. We report a case of left bundle branch block in a 35-year-old woman treated with INF beta-1a for multiple sclerosis. Five years after INF therapy, she presented loss of consciousness, retrosternal pains, short breath and lowered tolerance of effort. ECG and Holter 24-h ECG monitoring revealed permanent complete left bundle branch block. Nine months after stopping INF, no abnormalities were found at ECG and echocardiogram examination. © 2011 The Authors Fundamental and Clinical Pharmacology © 2011 Société Française de Pharmacologie et de Thérapeutique.

Radiotherapy as a cause of complete atrioventricular block in Hodgkin's disease. An electrophysiological-pathological correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, S.I.; Bharati, S.; Glass, J.

1981-04-01

A 20-year-old man contracted Hodgkin's disease and was treated with mantle radiotherapy. Heart block developed 11 years later. Electrocardiograms revealed predominant atrioventricular (AV) block and occasional AV conduction. Intracardiac electrograms demonstrated that the site of AV block was above the level of the His bundle. A permanent transvenous pacemaker was implanted. Seven months later the patient died of complications from cryptococcal meningitis. Pathological study of the heart revealed marked arteriosclerosis with fibrosis of the epicardium, myocardium, and endocardium. Examination of the conduction system revealed extensive arteriolosclerosis of the sinoatrial node and its approaches. In addition, there was marked fibrosis ofmore » the approaches to the AV node, the AV bundle, and both bundle branches. There was no evidence of Hodgkin's disease. This case documents the rare occurrence of AV block due to tissue destruction by radiotherapy. There was a good correlation between block proximal to the His bundle recording site and fibrosis of the approaches to the AV node.« less

Radiotherapy as a cause of complete atrioventricular block in Hodgkin's disease: an electrophysiological-pathological correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, S.I.; Bharati, S.; Glass, J.

1981-04-01

A 20-year-old man contracted Hodgkin's disease and was treated with mantle radiotherapy. Heart block developed 11 years later. Electrocardiograms revealed predominant atrioventricular (AV) block and occasional AV conduction. Intracardiac electrograms demonstrated that the site of AV block was above the level of the His bundle. A permanent transvenous pacemaker was implanted. Seven months later the patient died of complications from cryptococcal meningitis. Pathological study of the heart revealed marked arteriosclerosis with fibrosis of the epicardium, myocardium, and endocardium. Examination of the conduction system revealed extensive arteriolosclerosis of the sinoatrial node and its approaches. In addition, there was marked fibrosis ofmore » the approaches to the AV node, the AV bundle, and both bundle branches. There was no evidence of Hodgkin's disease. This case documents the rare occurrence of AV block due to tissue destruction by radiotherapy. There was a good correlation between block proximal to the His bundle recording site and fibrosis of the approaches to the AV node.« less

Evaluation of a New Cardiac Pacemaker

ClinicalTrials.gov

2013-06-25

Atrial Fibrillation With 2 or 3° AV or Bifascicular Bundle Branch (BBB) Block; Normal Sinus Rhythm With 2 or 3° AV or BBB Block; Sinus Bradycardia With Infrequent Pauses or Unexplained Syncope With EP Findings

New-Onset Left Bundle Branch Block Induced by Transcutaneous Aortic Valve Implantation.

PubMed

Massoullié, Grégoire; Bordachar, Pierre; Ellenbogen, Kenneth A; Souteyrand, Géraud; Jean, Frédéric; Combaret, Nicolas; Vorilhon, Charles; Clerfond, Guillaume; Farhat, Mehdi; Ritter, Philippe; Citron, Bernard; Lusson, Jean-R; Motreff, Pascal; Ploux, Sylvain; Eschalier, Romain

2016-03-01

New-onset left bundle branch block (LBBB) is a specific concern of transcutaneous aortic valve implantation (TAVI) given its estimated incidence ranging from 5% to 65%. This high rate of occurrence is dependent on the type of device used (size and shape), implantation methods, and patient co-morbidities. The appearance of an LBBB after TAVI reflects a very proximal lesion of the left bundle branch as it exits the bundle of His. At times transient, its persistence can lead to permanent pacemaker implantation in 15% to 20% of cases, most often for high-degree atrioventricular block. The management of LBBB after TAVI is currently not defined by international societies resulting in individual centers developing their own management strategy. The potential consequences of LBBB are dysrhythmias (atrioventricular block, syncope, and sudden death) and functional (heart failure) complications. Prompt postprocedural recognition and management (permanent pacemaker implantation) of patients prevents the occurrence of potential complications and may constitute the preferred approach in this frail and elderly population despite additional costs and complications of cardiac pacing. Moreover, the expansion of future indications for TAVI necessitates better identification of the predictive factors for the development of LBBB. Indeed, long-term right ventricular pacing may potentially increase the risk of developing heart failure in this population. In conclusion, it is thus imperative to not only develop new aortic prostheses with a less-deleterious impact on the conduction system but also to prescribe appropriate pacing modes in this frail population. Copyright © 2016 Elsevier Inc. All rights reserved.

Arrhythmogenic Right Ventricular Cardiomyopathy with Multiple Thrombi and Ventricular Tachycardia of Atypical Left Branch Bundle Block Morphology.

PubMed

Gong, Shenzhen; Wei, Xin; Liu, Guyue; Wu, Feng; Chen, Xiaoping

2018-04-06

A 61-year-old male patient was admitted to our hospital with recurrent palpitations and syncope. Electrocardiography, echocardiography, and contrast-enhanced computed tomography were performed. The patient was diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) complicated by multiple thrombi, and ventricular tachycardia (VT) without typical left bundle branch block (LBBB) morphology. This case suggests that VT is not always the sole contributor to syncope and death in patients with ARVC, and pulmonary embolism should be considered. Furthermore, VT with typical LBBB morphology is not an absolute necessity as a major criterion for the diagnosis of ARVC when the right heart is extremely enlarged.

Transient left septal and anterior fascicular block associated with type 1 electrocardiographic Brugada pattern.

PubMed

Pérez-Riera, Andrés Ricardo; Barbosa-Barros, Raimundo; Penachini da Costa de Rezende Barbosa, Marianne; Daminello-Raimundo, Rodrigo; de Abreu, Luiz Carlos

The left septal fascicular block (LSFB) or blockage of the middle fibers of the left bundle branch is probably caused mainly by - in the developed world - the proximal obstruction of the left anterior descending artery (LAD) before its first anterior septal perforator branch (S 1 ). The association of transient LSFB and left anterior fascicular block (LAFB) - left bifascicular block - and the electrocardiographic type 1 Brugada pattern (BrP) has not been described in the literature yet. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrocardiographic Findings in Patients With Acute Coronary Syndrome Presenting With Out-of-Hospital Cardiac Arrest.

PubMed

Sarak, Bradley; Goodman, Shaun G; Brieger, David; Gale, Chris P; Tan, Nigel S; Budaj, Andrzej; Wong, Graham C; Huynh, Thao; Tan, Mary K; Udell, Jacob A; Bagai, Akshay; Fox, Keith A A; Yan, Andrew T

2018-02-01

We sought to characterize presenting electrocardiographic findings in patients with acute coronary syndromes (ACSs) and out-of-hospital cardiac arrest (OHCA). In the Global Registry of Acute Coronary Events and Canadian ACS Registry I, we examined presenting and 24- to 48-hour follow-up ECGs (electrocardiogram) of ACS patients who survived to hospital admission, stratified by presentation with OHCA. We assessed the prevalence of ST-segment deviation and bundle branch blocks (assessed by an independent ECG core laboratory) and their association with in-hospital and 6-month mortality among those with OHCA. Of the 12,040 ACS patients, 215 (1.8%) survived to hospital admission after OHCA. Those with OHCA had higher presenting rates of ST-segment elevation, ST-segment depression, T-wave inversion, precordial Q-waves, left bundle branch block (LBBB), and right bundle branch block (RBBB) than those without. Among patients with OHCA, those with ST-segment elevation had significantly lower in-hospital mortality (20.9% vs 33.0%, p = 0.044) and a trend toward lower 6-month mortality (27% vs 39%, p = 0.060) compared with those without ST-segment elevation. Conversely, among OCHA patients, LBBB was associated with significantly higher in-hospital and 6-month mortality rates (58% vs 22%, p <0.001, and 65% vs 28%, p <0.001, respectively). ST-segment depression and RBBB were not associated with either outcome. Sixty-three percent of bundle branch blocks (RBBB or LBBB) on the presenting ECG resolved by 24 to 48 hours. In conclusion, compared with ACS patients without cardiac arrest, those with OHCA had higher rates of ST-segment elevation, LBBB, and RBBB on admission. Among OHCA patients, ST-segment elevation was associated with lower in-hospital mortality, whereas LBBB was associated with higher in-hospital and 6-month mortality. Copyright © 2017 Elsevier Inc. All rights reserved.

Reversible chronic acquired complete atrioventricular block.

PubMed

Rakovec, P; Milcinski, G; Voga, G; Korsic, L

1982-01-01

The return of atrioventricular conduction is reported in a case after nearly four years of complete acquired heart block. After recovery from atrioventricular block, right bundle branch block persisted, but P-R interval and H-V interval were normal. Three months later a relapse of second degree infranodal atrioventricular block was noted. A short review of similar cases from the literature is given.

Comparison of the calculation QRS angle for bundle branch block detection

NASA Astrophysics Data System (ADS)

Goeirmanto, L.; Mengko, R.; Rajab, T. L.

2016-04-01

QRS angle represent condition of blood circulation in the heart. Normally QRS angle is between -30 until 90 degree. Left Axis Defiation (LAD) and Right Axis Defiation (RAD) are abnormality conditions that lead to Bundle Branch Block. QRS angle is calculated using common method from physicians and compared to mathematical method using difference amplitudos and difference areas. We analyzed the standard 12 lead electrocardiogram data from MITBIH physiobank database. All methods using lead I and lead avF produce similar QRS angle and right QRS axis quadrant. QRS angle from mathematical method using difference areas is close to common method from physician. Mathematical method using difference areas can be used as a trigger for detecting heart condition.

Chronic hypertension with subsequent congestive heart failure in a western lowland gorilla (Gorilla gorilla gorilla).

PubMed

Miller, C L; Schwartz, A M; Barnhart, J S; Bell, M D

1999-06-01

Chronic severe subclinical systemic hypertension was diagnosed in a 28-yr-old male western lowland gorilla (Gorilla gorilla gorilla). Thoracic radiography, electrocardiography, and echocardiography revealed an enlarged heart with a hypertrophied left ventricle, mitral regurgitation, and a persistent left bundle branch block. Enalapril, later combined with nifedipine, was of some value in reducing the hypertension, with partial reversal of cardiac enlargement and resolution of the bundle branch block. Two years after initiation of treatment, the gorilla developed lethargy and dyspnea. The diagnosis of heart failure was confirmed under anesthesia; the gorilla did not recover and was euthanized. Postmortem examination confirmed congestive heart failure with chronic, fibrosing cardiomyopathy similar to that in other gorillas.

Trastuzumab (Herceptin)-associated cardiomyopathy presented as new onset of complete left bundle-branch block mimicking acute coronary syndrome: a case report and literature review.

PubMed

Tu, Chung-Ming; Chu, Kai-Ming; Yang, Shin-Ping; Cheng, Shu-Mung; Wang, Wen-Been

2009-09-01

Trastuzumab (Herceptin) is well documented in reducing suffering and mortality from breast cancer. The clinically most important side effect of Herceptin is cardiotoxicity, which is reported in 2.6% to 4.5% of patients receiving trastuzumab alone and in as many as 27% of patients when trastuzumab is combined with an anthracycline in metastatic disease. We reported the case of a 50-year-old woman who presented to our emergency department (ED) because of chest pain and shortness of breath. On physical examination, holosystolic murmur over apex could be heard. Pulmonary and abdominal examinations were unremarkable. Twelve-lead electrocardiography showed sinus tachycardia and new onset of complete left bundle-branch block. Emergent transthoracic echocardiography revealed generalized hypokinesia of left ventricle and akinesia over interventricular septum and apex. She subsequently underwent immediate coronary angiography that revealed normal coronary angiography, and left ventriculogram revealed generalized hypokinesia with severe left ventricle dysfunction with ejection fraction of 33%. During right heart catheterization and endomyocardial biopsy, cardiac tamponade developed and was successfully relieved by pericardial window. She was discharged event-free 3 weeks later with conservative treatment. Although new onset of complete left bundle-branch block in a patient with chest pain may be acute coronary syndrome, careful review of medicine history is mandatory to avoid unnecessary procedure and complications.

Naval Air Development Center Medical Standards for Research Subjects Exposed to Hazardous Aerospace Environments

DTIC Science & Technology

1991-02-01

evidence of isolated hypertrophy compatible with athletic training. c. Left or right bundle branch block. d. Wolff - Parkinson - White or other pre-excitation... syndrome . e. Second or third-degree heart block. (Atrio-ventricular dissociation post-stress is not necessarily disqualifying.) f. QT-prolongation (QTc

Sgarbossa criteria and acute myocardial infarction.

PubMed

Alang, Neha; Bathina, Jaya; Kranis, Mark; Angelis, Dimitrios

2010-01-01

Diagnosis of acute ST-elevation myocardial infarction in the presence of left bundle branch block is difficult. present a case of acute myocardial infarction with LBBB diagnosed and treated using the Sgarbossa criteria.

Acquired left bundle branch block in an asymptomatic fighter pilot: a case report.

PubMed

Newman, D G

1999-12-01

This report describes a case of acquired left bundle branch block (LBBB) in an asymptomatic F/A-18 fighter pilot of the Royal Australian Air Force. The previously fit and healthy pilot was found to have LBBB on routine electrocardiographic screening prior to his annual aircrew medical. He was completely asymptomatic, and the only potential etiological factor was a short-lived acute gastrointestinal infectious illness some 4 mo previously. The pilot was extensively investigated with the full range of available diagnostic procedures, including coronary angiography and cardiac biopsy. No cause was determined for his LBBB pattern, and he was assessed as having normal cardiovascular function. The aeromedical disposition of this aviator and the issues involved in determining fitness to fly in such a case are discussed. The importance of thorough clinical investigation and appropriate follow-up are highlighted.

Rare case of left-dominant arrhythmogenic right ventricular cardiomyopathy with dramatic reverse remodeling after cardiac resynchronization as an adjunct to pharmacological therapy.

PubMed

Hsiao, Chih-Chung; Kuo, Jen-Yuan; Yun, Chun-Ho; Hung, Chung-Lieh; Tsai, Cheng-Ho; Yeh, Hung-I

2012-01-01

A 57-year-old man presented with near syncope and hemodynamic compromise after exercise. A sustained ventricular tachycardia (VT) of right bundle-branch block morphology was evident upon examination at our emergency department. Baseline 12-lead electrocardiography revealed a sinus rhythm with a complete left bundle-branch block after successful cardioversion of the VT. Coronary angiography revealed patent coronary arteries, whereas left ventriculography demonstrated impaired systolic function, accompanied by a peculiar basal lateral aneurysm. Both echocardiography and magnetic resonance imaging were consistent with a diagnosis of left-dominant arrhythmogenic right ventricular cardiomyopathy. Four months later, substantial ventricular reverse remodeling and clinical improvements were observed after cardiac resynchronization therapy with a defibrillator, as an adjunct to conventional pharmacological therapy. Copyright © 2012 Elsevier Inc. All rights reserved.

Left bundle branch block, an old-new entity.

PubMed

Breithardt, Günter; Breithardt, Ole-Alexander

2012-04-01

Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right bundle branch block which is generally considered to be benign in the absence of an underlying cardiac disorder like congenital heart disease. LBBB may be the first manifestation of a more diffuse myocardial disease. The typical surface ECG feature of LBBB is a prolongation of QRS above 0.11 s in combination with a delay of the intrinsic deflection in leads V5 and V6 of more than 60 ms and no septal q waves in leads I, V5, and V6 due to the abnormal septal activation from right to left. LBBB may induce abnormalities in left ventricular performance due to abnormal asynchronous contraction patterns which can be compensated by biventricular pacing (resynchronization therapy). Asynchronous electrical activation of the ventricles causes regional differences in workload which may lead to asymmetric hypertrophy and left ventricular dilatation, especially due to increased wall mass in late-activated regions, which may aggravate preexisting left ventricular pumping performance or even induce it. Of special interest are patients with LBBB and normal left ventricular dimensions and normal ejection fraction at rest but who may present with an abnormal increase in pulmonary artery pressure during exercise, production of lactate during high-rate pacing, signs of ischemia on myocardial scintigrams (but no coronary artery narrowing), and abnormal ultrastructural findings on myocardial biopsy. For this entity, the term latent cardiomyopathy had been suggested previously.

Twelve-lead electrocardiography in the young: physiologic and pathologic abnormalities.

PubMed

Kobza, Richard; Cuculi, Florim; Abächerli, Roger; Toggweiler, Stefan; Suter, Yves; Frey, Franz; Schmid, Johann Jakob; Erne, Paul

2012-12-01

BACKGROUND/ OBJECTIVE: The purpose of the present study was to analyze the prevalence of physiologic and pathologic ECG abnormalities in a cohort of young conscripts that represents the whole young generation of today. ECGs of all Swiss citizens who underwent conscription for the army during a 29-month period were analyzed manually. ECGs of 43,401 conscripts (mean age 19.2 ± 1.1 years) were analyzed; 158 conscripts were female. Incomplete right bundle branch block was found in 5870 (13.5%) and left anterior fascicular block in 360 (0.83%). First-degree AV block was present in 329 (0.8%) and Mobitz type I (Wenckebach) second-degree AV block in 3 (0.01%). Early repolarization was observed in 1035 (2.4%), T-wave inversion in 39 (0.09%), and minor T-wave changes in 182 (0.42%). Brugada-like abnormalities were observed in 6 (0.01%). None of the conscripts had atrial fibrillation or flutter. ECG abnormalities can be found in a relatively large proportion of young individuals. Incomplete right bundle branch block, left fascicular block, and first-degree AV block are the most frequent findings. No conscript presented with atrial fibrillation or flutter. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Computerized analysis of the 12-lead electrocardiogram to identify epicardial ventricular tachycardia exit sites.

PubMed

Yokokawa, Miki; Jung, Dae Yon; Joseph, Kim K; Hero, Alfred O; Morady, Fred; Bogun, Frank

2014-11-01

Twelve-lead electrocardiogram (ECG) criteria for epicardial ventricular tachycardia (VT) origins have been described. In patients with structural heart disease, the ability to predict an epicardial origin based on QRS morphology is limited and has been investigated only for limited regions in the heart. The purpose of this study was to determine whether a computerized algorithm is able to accurately differentiate epicardial vs endocardial origins of ventricular arrhythmias. Endocardial and epicardial pace-mapping were performed in 43 patients at 3277 sites. The 12-lead ECGs were digitized and analyzed using a mixture of gaussian model (MoG) to assess whether the algorithm was able to identify an epicardial vs endocardial origin of the paced rhythm. The MoG computerized algorithm was compared to algorithms published in prior reports. The computerized algorithm correctly differentiated epicardial vs endocardial pacing sites for 80% of the sites compared to an accuracy of 42% to 66% of other described criteria. The accuracy was higher in patients without structural heart disease than in those with structural heart disease (94% vs 80%, P = .0004) and for right bundle branch block (82%) compared to left bundle branch block morphologies (79%, P = .001). Validation studies showed the accuracy for VT exit sites to be 84%. A computerized algorithm was able to accurately differentiate the majority of epicardial vs endocardial pace-mapping sites. The algorithm is not region specific and performed best in patients without structural heart disease and with VTs having a right bundle branch block morphology. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

An Energy Efficient ECG Signal Processor Detecting Cardiovascular Diseases on Smartphone.

PubMed

Jain, Sanjeev Kumar; Bhaumik, Basabi

2017-04-01

A novel disease diagnostic algorithm for ECG signal processing based on forward search is implemented in Application Specific Integrated Circuit (ASIC) for cardiovascular disease diagnosis on smartphone. An ASIC is fabricated using 130-nm CMOS low leakage process technology. The area of our PQRST ASIC is 1.21 mm 2 . The energy dissipation of PQRST ASIC is 96 pJ with a supply voltage of 0.9 V. The outputs from the ASIC are fed to an Android application that generates diagnostic report and can be sent to a cardiologist via email. The ASIC and Android application are verified for the detection of bundle branch block, hypertrophy, arrhythmia and myocardial infarction using Physionet PTB diagnostic ECG database. The failed detection rate is 0.69%, 0.69%, 0.34% and 1.72% for bundle branch block, hypertrophy, arrhythmia and myocardial infarction respectively. The AV block is detected in all the three patients in the Physionet St. Petersburg arrhythmia database. Our proposed ASIC together with our Android application is the most suitable for an energy efficient wearable cardiovascular disease detection system.

Pulmonary Right Ventricular Resynchronization in Congenital Heart Disease: Acute Improvement in Right Ventricular Mechanics and Contraction Efficiency.

PubMed

Janoušek, Jan; Kovanda, Jan; Ložek, Miroslav; Tomek, Viktor; Vojtovič, Pavel; Gebauer, Roman; Kubuš, Peter; Krejčíř, Miroslav; Lumens, Joost; Delhaas, Tammo; Prinzen, Frits

2017-09-01

Electromechanical discoordination may contribute to long-term pulmonary right ventricular (RV) dysfunction in patients after surgery for congenital heart disease. We sought to evaluate changes in RV function after temporary RV cardiac resynchronization therapy. Twenty-five patients aged median 12.0 years after repair of tetralogy of Fallot and similar lesions were studied echocardiographically (n=23) and by cardiac catheterization (n=5) after primary repair (n=4) or after surgical RV revalvulation for significant pulmonary regurgitation (n=21). Temporary RV cardiac resynchronization therapy was applied in the presence of complete right bundle branch block by atrial-synchronized RV free wall pacing in complete fusion with spontaneous ventricular depolarization using temporary electrodes. The q-RV interval at the RV free wall pacing site (mean 77.2% of baseline QRS duration) confirmed pacing from a late activated RV area. RV cardiac resynchronization therapy carried significant decrease in QRS duration ( P <0.001) along with elimination of the right bundle branch block QRS morphology, increase in RV filling time ( P =0.002), pulmonary artery velocity time integral ( P =0.006), and RV maximum +dP/dt ( P <0.001), and decrease in RV index of myocardial performance ( P =0.006). RV mechanical synchrony improved: septal-to-lateral RV mechanical delay decreased ( P <0.001) and signs of RV dyssynchrony pattern were significantly abolished. RV systolic stretch fraction reflecting the ratio of myocardial stretching and contraction during systole diminished ( P =0.001). In patients with congenital heart disease and right bundle branch block, RV cardiac resynchronization therapy carried multiple positive effects on RV mechanics, synchrony, and contraction efficiency. © 2017 American Heart Association, Inc.

Machine Learning Algorithm Predicts Cardiac Resynchronization Therapy Outcomes: Lessons From the COMPANION Trial.

PubMed

Kalscheur, Matthew M; Kipp, Ryan T; Tattersall, Matthew C; Mei, Chaoqun; Buhr, Kevin A; DeMets, David L; Field, Michael E; Eckhardt, Lee L; Page, C David

2018-01-01

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure patients with reduced left ventricular function and intraventricular conduction delay. However, individual outcomes vary significantly. This study sought to use a machine learning algorithm to develop a model to predict outcomes after CRT. Models were developed with machine learning algorithms to predict all-cause mortality or heart failure hospitalization at 12 months post-CRT in the COMPANION trial (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure). The best performing model was developed with the random forest algorithm. The ability of this model to predict all-cause mortality or heart failure hospitalization and all-cause mortality alone was compared with discrimination obtained using a combination of bundle branch block morphology and QRS duration. In the 595 patients with CRT-defibrillator in the COMPANION trial, 105 deaths occurred (median follow-up, 15.7 months). The survival difference across subgroups differentiated by bundle branch block morphology and QRS duration did not reach significance ( P =0.08). The random forest model produced quartiles of patients with an 8-fold difference in survival between those with the highest and lowest predicted probability for events (hazard ratio, 7.96; P <0.0001). The model also discriminated the risk of the composite end point of all-cause mortality or heart failure hospitalization better than subgroups based on bundle branch block morphology and QRS duration. In the COMPANION trial, a machine learning algorithm produced a model that predicted clinical outcomes after CRT. Applied before device implant, this model may better differentiate outcomes over current clinical discriminators and improve shared decision-making with patients. © 2018 American Heart Association, Inc.

A case of hypopituitarism accompanying Kearns-Sayre syndrome treated with human chorionic gonadotropin: A case report and literature review.

PubMed

Kang, Y-X; Wang, Y-J; Zhang, Q; Pang, X-H; Gu, W

2017-10-01

Kearns-Sayre syndrome (KSS) is a disorder caused by mutations in mitochondrial DNA. Here, we report an unusual case of Kearns-Sayre syndrome accompanied by hypopituitarism (deficiencies in reproductive and growth hormones). A 20-year-old male presented with growth retardation for the last 8 years, as well as the following findings: short stature, delayed puberty, myasthenia, an extraocular movement deficit, drooping eyelids, pectus carinatum and scoliosis. Cerebral enhanced magnetic resonance imaging revealed dysplasias of the pituitary, white matter and cerebellum. Laboratory work-up showed subnormal testosterone and growth hormone levels, a subnormal testicular volume, sensorineural deafness, pigmentary retinopathy, complete right bundle branch block and left anterior bundle branch block. Pathological examination revealed ragged red muscle fibres. Thus, this rare case involved the coexistence of Kearns-Sayre syndrome and hypopituitarism in a patient. Administration of coenzyme Q10 for the KSS and hormone replacement therapy for the endocrinopathies were performed for treatment of this patient. © 2016 Blackwell Verlag GmbH.

Onset of recent exertional dyspnoea in a firefighter with left bundle-branch block

PubMed Central

De Rosa, Roberto; Ratti, Gennaro; Lamberti, Monica

2014-01-01

Background The presence of a left bundle-branch block (LBBB) among firefighters raises questions about stratifying risk of subsequent cardiovascular events as this conduction disorder may mask underlying coronary artery disease. This report describes the case of a firefighter with a history LBBB with exertional dyspnoea of recent onset after work activity. Case report A 39-year-old male firefighter with LBBB developed exertional dyspnoea after a prolonged session of work. ECG and treadmill test only showed a permanent LBBB; echocardiography and myocardial scintigraphy did not add to this. However, multislice CT (MSCT) showed a significant stenosis in the mid-left anterior descending artery (LAD). Coronary angiography confirmed the stenosis with subsequent placement of a coronary stent. Conclusions An occupational physician should take into account that factors such as age and low cardiovascular risk do not always exclude heart disease, especially when there are conduction system abnormalities that can mask possible coronary artery disease. PMID:25352387

Onset of recent exertional dyspnoea in a firefighter with left bundle-branch block.

PubMed

De Rosa, Roberto; Ratti, Gennaro; Lamberti, Monica

2014-10-28

The presence of a left bundle-branch block (LBBB) among firefighters raises questions about stratifying risk of subsequent cardiovascular events as this conduction disorder may mask underlying coronary artery disease. This report describes the case of a firefighter with a history LBBB with exertional dyspnoea of recent onset after work activity. A 39-year-old male firefighter with LBBB developed exertional dyspnoea after a prolonged session of work. ECG and treadmill test only showed a permanent LBBB; echocardiography and myocardial scintigraphy did not add to this. However, multislice CT (MSCT) showed a significant stenosis in the mid-left anterior descending artery (LAD). Coronary angiography confirmed the stenosis with subsequent placement of a coronary stent. An occupational physician should take into account that factors such as age and low cardiovascular risk do not always exclude heart disease, especially when there are conduction system abnormalities that can mask possible coronary artery disease. 2014 BMJ Publishing Group Ltd.

Inhomogeneity of block copolymers at the interface of an immiscible polymer blend

NASA Astrophysics Data System (ADS)

Ryu, Ji Ho; Kim, YongJoo; Lee, Won Bo

2018-04-01

We present the effects of structure and stiffness of block copolymers on the interfacial properties of an immiscible homopolymer blend. Diblock and two-arm grafted copolymers with variation in stiffness are modeled using coarse-grained molecular dynamics to compare the compatibilization efficiency, i.e., reduction of interfacial tension. Overall, grafted copolymers are located more compactly at the interface and show better compatibilization efficiency than diblock copolymers. In addition, an increase in the stiffness for one of the blocks of the diblock copolymers causes unusual inhomogeneous interfacial coverage due to bundle formation. However, an increase in the stiffness for one of blocks of the grafted copolymers prevents the bundle formation due to the branched chain. As a result, homogeneous interfacial coverage of homopolymer blends is realized with significant reduction of interfacial tension which makes grafted copolymer a better candidate for the compatibilizer of immiscible homopolymer blend.

Nonalcoholic fatty liver disease is associated with an increased risk of heart block in hospitalized patients with type 2 diabetes mellitus.

PubMed

Mantovani, Alessandro; Rigolon, Riccardo; Pichiri, Isabella; Bonapace, Stefano; Morani, Giovanni; Zoppini, Giacomo; Bonora, Enzo; Targher, Giovanni

2017-01-01

Recent studies suggested that nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiac tachyarrhythmias (mainly atrial fibrillation) in patients with and without type 2 diabetes mellitus. The aim of this study was to examine whether an association also exists between NAFLD and heart block. We have retrospectively evaluated a hospital-based cohort of 751 patients with type 2 diabetes discharged from our Division of Diabetes and Endocrinology during years 2007-2014. Standard electrocardiograms were performed on all patients. Diagnosis of NAFLD was based on ultrasonography, whereas the severity of advanced hepatic fibrosis was based on the fibrosis (FIB)-4 score and other non-invasive fibrosis markers. Overall, 524 (69.8%) patients had NAFLD and 202 (26.9%) had heart block (defined as at least one block among first-degree atrio-ventricular block, second-degree block, third-degree block, left bundle branch block, right bundle branch block, left anterior hemi-block or left posterior hemi-block) on electrocardiograms. Patients with NAFLD had a remarkably higher prevalence of any persistent heart block than those without NAFLD (31.3% vs. 16.7%, p<0.001); this prevalence was particularly increased among those with higher FIB-4 score. NAFLD was associated with a threefold increased risk of prevalent heart block (adjusted-odds ratio 3.04, 95% CI 1.81-5.10), independently of age, sex, hypertension, prior ischemic heart disease, hemoglobin A1c, microvascular complication status, use of medications and other potentially confounding factors. In conclusion, this is the largest cross-sectional study to show that NAFLD and its severity are independently associated with an increased risk of prevalent heart block in hospitalized patients with type 2 diabetes.

Is there a prognostic relevance of electrophysiological studies in bundle branch block patients?

PubMed

Bogossian, Harilaos; Frommeyer, Gerrit; Göbbert, Kornelius; Hasan, Fuad; Nguyen, Quy Suu; Ninios, Ilias; Mijic, Dejan; Bandorski, Dirk; Hoeltgen, Reinhard; Seyfarth, Melchior; Lemke, Bernd; Eckardt, Lars; Zarse, Markus

2017-08-01

The present European guidelines suggest a diagnostic electrophysiological (EP) study to determine indication for cardiac pacing in patients with bundle branch block and unexplained syncope. We evaluated the prognostic relevance of an EP study for mortality and the development of permanent complete atrioventricular (AV) block in patients with symptomatic bifascicular block and first-degree AV block. The HV interval is a poor prognostic marker to predict the development of permanent AV block in patients with symptomatic bifascicular block (BFB) and AV block I°. Thirty consecutive patients (mean age, 74.8 ± 8.6 years; 25 males) with symptomatic BFB and first-degree AV block underwent an EP study before device implantation, according to current guidelines. For 53 ± 31 months, patients underwent yearly follow-up screening for syncope or higher-degree AV block. Thirty patients presented with prolonged HV interval during the EP study (mean, 82.2 ± 20.1 ms; range, 57-142 ms), classified into 3 groups: group 1, <70 ms (mean, 62 ± 4 ms; range, 57-67 ms; n = 7), group 2, >70 to ≤100 ms (mean, 80 ± 8 ms; range, 70-97 ms; n = 18), and group 3, >100 ms (mean, 119 ± 14 ms; range, 107-142 ms; n = 5). According to the guidelines, patients in groups 2 and 3 received a pacemaker. The length of the HV interval was not associated with the later development of third-degree AV block or with increased mortality. Our present study suggests that an indication for pacemaker implantation based solely on a diagnostic EP study with prolongation of the HV interval is not justified. © 2017 Wiley Periodicals, Inc.

Idiopathic accelerated idioventricular rhythm or ventricular tachycardia originating from the right bundle branch: unusual type of ventricular arrhythmia.

PubMed

Chen, Minglong; Gu, Kai; Yang, Bing; Chen, Hongwu; Ju, Weizhu; Zhang, Fengxiang; Yang, Gang; Li, Mingfang; Lu, Xinzheng; Cao, Kejiang; Ouyang, Feifan

2014-12-01

Accelerated idioventricular rhythm (AIVR) or ventricular tachycardia (VT) originating from the right bundle branch (RBB) is rare and published clinical data on such arrhythmia are scarce. In this study, we will describe the clinical manifestations, diagnosis, and management of a cohort of patients with this novel arrhythmia. Eight patients (5 men; median age, 25 years) with RBB-AIVR/VT were consecutively enrolled in the study. Pharmacological testing, exercise treadmill testing, electrophysiological study, and catheter ablation were performed in the study patients, and ECG features were characterized. All RBB-AIVR/VTs were of typical left bundle-branch block morphology with atrioventricular dissociation. The arrhythmias, which demonstrated chronotropic variability, were often isorhythmic with sinus rhythm and were accelerated by physical exercise, stress, and intravenous isoprenaline infusion. The rate of RBB-AIVR/VT varied from 45 to 200 beats per minute. Two patients experienced syncope, and 3 had impaired left ventricular function. Metoprolol was proven to be the most effective drug to decelerate the arrhythmia rate and relieve symptoms. Electrophysiology study was performed in 5 patients and the earliest activation with a sharp RBB potential was localized in the mid or distal RBB area. Catheter ablation terminated the arrhythmia with subsequent RBB block morphology during sinus rhythm. During follow-up, patients' symptoms were controlled with normalization of left ventricular function either on metoprolol or by catheter ablation. RBB-AIVR/VT is an unusual type of ventricular arrhythmia. It can result in significant symptoms and depressed ventricular function and can be successfully treated with catheter ablation. © 2014 American Heart Association, Inc.

Diagnosis of Brugada's syndrome after subarachnoid injection of prilocaine.

PubMed

Oliván, B; Arbeláez, A; de Miguel, M; Pelavski, A

2016-10-01

Brugada syndrome is an autosomal dominant genetic disease affecting sodium ion channels. It is characterised by right bundle branch block and ST elevation in the right precordial leads, and with no structural cardiac abnormalities. It is associated with sudden death. This disease may be unmasked by certain drugs and sudden changes in autonomic tone. Local anaesthetics may increase ECG changes due to a blockade of the sodium channels, mainly depending on the dose and the type of anaesthetic. Thus, there have been reported electrocardiographic changes consistent with Brugada syndrome, triggered after epidural or paravertebral infusion of bupivacaine and ropivacaine. The case is described of a 66 years old man, scheduled for inguinal herniorrhaphy as an outpatient. He had no history of syncope or arrhythmias. After spinal anaesthesia with 40mg of prilocaine the ECG showed ST elevation>2mm, and right bundle branch block in V1-V3. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

The prognostic value of a new left bundle branch block in patients with acute myocardial infarction: A systematic review and meta-analysis.

PubMed

Al Rajoub, Belal; Noureddine, Samar; El Chami, Samer; Haidar, Mohamad Hussein; Itani, Bachir; Zaiter, Aida; Akl, Elie A

To assess the prognostic value of new left bundle branch block (LBBB) in patients with acute myocardial infarction (AMI). LBBB develops in many cardiac conditions, including AMI. The empirical evidence for the contribution of LBBB to mortality in AMI is not consistent. Medline, PubMed, CINAHL, and EMBASE were searched. Inverse variance meta-analysis was performed with odds ratios as the effect estimates. The I 2 statistic and risk of bias were assessed. Eight studies involving 105,861 participants were eligible. New LBBB was associated with higher mortality at 30 days (OR: 2.10, 95% CI 1.27 to 3.48) and 1-year follow up (OR: 2.81, 95% CI 1.64 to 4.80), and increased heart failure risk (OR: 2.64, 95% CI 1.84 to 3.77). AMI patients with new LBBB are a high risk group and must be treated accordingly. Yet, more research is needed given the limitations of studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Conduction disturbances after TAVR: Electrophysiological studies and pacemaker dependency.

PubMed

Makki, Nader; Dollery, Jenn; Jones, Danielle; Crestanello, Juan; Lilly, Scott

Permanent pacemaker (PPM) placement occurs in 5-20% of patients after transcatheter aortic valve replacement (TAVR). Although predictors of pacemaker implantation have been established, features that predispose patients to pacemaker utilization on follow up have not been widely reported. We performed a retrospective review of patients undergoing commercial TAVR between 2011 and 2016. We collated patients that underwent in-hospital PPM implantation and had a follow up of at least 3months. Data abstraction was performed for electrophysiological studies (EPS), pacemaker indication, timing, and device interrogation for pacemaker dependency on follow up. A total of 24 patients received in-hospital PPM post-TAVR (14% of total cohort), and mean follow up was 22months. Indications for PPM included resting complete heart block (CHB; 15/24, 63%), left bundle branch block and abnormal electrophysiological study (EPS; 7/24, 29%), alternating bundle branch block (1/24, 4%) and tachy-brady syndrome (1/24, 4%). Pacemaker dependency (underlying ventricular asystole, complete heart block, or >50% pacing) occurred in 8/24 patients (33%) during follow-up, 7 of whom had resting CHB, and one with CHB invoked during EPS. Pacemaker dependency after TAVR is common among those that exhibited CHB, but not among those with a prolonged HV delay during EPS. Although preliminary, these observations are relevant to management of rhythm disturbances after TAVR, and may inform the practice of EPS-based PPM implantation. Copyright © 2017 Elsevier Inc. All rights reserved.

Programming Cardiac Resynchronization Therapy for Electrical Synchrony: Reaching Beyond Left Bundle Branch Block and Left Ventricular Activation Delay.

PubMed

Varma, Niraj; O'Donnell, David; Bassiouny, Mohammed; Ritter, Philippe; Pappone, Carlo; Mangual, Jan; Cantillon, Daniel; Badie, Nima; Thibault, Bernard; Wisnoskey, Brian

2018-02-06

QRS narrowing following cardiac resynchronization therapy with biventricular (BiV) or left ventricular (LV) pacing is likely affected by patient-specific conduction characteristics (PR, qLV, LV-paced propagation interval), making a universal programming strategy likely ineffective. We tested these factors using a novel, device-based algorithm (SyncAV) that automatically adjusts paced atrioventricular delay (default or programmable offset) according to intrinsic atrioventricular conduction. Seventy-five patients undergoing cardiac resynchronization therapy (age 66±11 years; 65% male; 32% with ischemic cardiomyopathy; LV ejection fraction 28±8%; QRS duration 162±16 ms) with intact atrioventricular conduction (PR interval 194±34, range 128-300 ms), left bundle branch block, and optimized LV lead position were studied at implant. QRS duration (QRSd) reduction was compared for the following pacing configurations: nominal simultaneous BiV (Mode I: paced/sensed atrioventricular delay=140/110 ms), BiV+SyncAV with 50 ms offset (Mode II), BiV+SyncAV with offset that minimized QRSd (Mode III), or LV-only pacing+SyncAV with 50 ms offset (Mode IV). The intrinsic QRSd (162±16 ms) was reduced to 142±17 ms (-11.8%) by Mode I, 136±14 ms (-15.6%) by Mode IV, and 132±13 ms (-17.8%) by Mode II. Mode III yielded the shortest overall QRSd (123±12 ms, -23.9% [ P <0.001 versus all modes]) and was the only configuration without QRSd prolongation in any patient. QRS narrowing occurred regardless of QRSd, PR, or LV-paced intervals, or underlying ischemic disease. Post-implant electrical optimization in already well-selected patients with left bundle branch block and optimized LV lead position is facilitated by patient-tailored BiV pacing adjusted to intrinsic atrioventricular timing using an automatic device-based algorithm. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Technology Advances to Improve Response to Cardiac Resynchronization Therapy: What Clinicians Should Know.

PubMed

Auricchio, Angelo; Heggermont, Ward A

2018-06-01

Cardiac resynchronization therapy (CRT) is a well-established treatment for symptomatic heart failure patients with reduced left ventricular ejection fraction, prolonged QRS duration, and abnormal QRS morphology. The ultimate goals of modern CRT are to improve the proportion of patients responding to CRT and to maximize the response to CRT in patients who do respond. While the rate of CRT nonresponders has moderately but progressively decreased over the last 20 years, mostly in patients with left bundle branch block, in patients without left bundle branch block the response rate is almost unchanged. A number of technological advances have already contributed to achieve some of the objectives of modern CRT. They include novel lead design (the left ventricular quadripolar lead, and multipoint pacing), or the possibility to go beyond conventional delivery of CRT (left ventricular endocardial pacing, His bundle pacing). Furthermore, to improve CRT response, a triad of actions is paramount: reducing the burden of atrial fibrillation, reducing the number of appropriate and inappropriate interventions, and adequately predicting heart failure episodes. As in other fields of cardiology, technology and innovations for CRT delivery have been at the forefront in transforming-improving-patient care; therefore, these innovations are discussed in this review. Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Rate-Related Left Bundle Branch Block and Cardiac Memory in a Patient with Bradycardia: Case Report and Literature Review.

PubMed

Seibolt, Luke; Maestas, Camila; Lazkani, Mohamad; Fatima, Umaima; Loli, Akil; Chesser, Michael

2018-06-19

Rate-related left bundle branch block (LBBB) is a well-studied phenomenon. Cardiac memory is another physiologic phenomenon in which T-wave abnormalities occur in the absence of ischemia. The association between these two phenomena has been described in several case reports. A literature review was performed through OVID and Pubmed, where at total of 93 cases of rate- related LBBB were identified. Cases were reviewed and data were collected on rates of appearance and disappearance as well as the presence or absence of cardiac memory. There is some overlap in the rate at which LBBB appear. Cardiac memory is associated with rate-related LBBB in several cases but its true prevalence is unknown. Cardiac memory is a phenomenon that is well described in the literature but is often under-recognized in clinical practice. As a consequence of overlooking this phenomenon and not including cardiac memory in the differential when T-wave abnormalities are observed, patients may be subjected to unnecessary invasive diagnostic testing. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Wolff-Parkinson-white syndrome mimics a conduction disease.

PubMed

Marrakchi, S; Kammoun, I; Kachboura, S

2014-01-01

Background. It is important to recognise Wolff-Parkinson-White (WPW) syndrome in electrocardiograms (ECG), as it may mimic ischaemic heart disease, ventricular hypertrophy, and bundle branch block. Recognising WPW syndrome allows for risk stratification, the identification of associated conditions, and the institution of appropriate management. Objective. The present case showed that electrophysiological study is indicated in patients with abnormal ECG and syncope. Case Report. A 40-year-old man with Wolff-Parkinson-White syndrome was presented to emergency with syncope. A baseline ECG was a complete right branch block and posterior left hemiblock. He was admitted to the cardiac care unit for pacemaker implantation. The atypical figure of complete right branch block and posterior left hemiblock was thought to be a "false positive" of conduction abnormality. But the long anterograde refractory period of the both accessory pathway and atrioventricular conduction may cause difficulty in diagnosing Wolff-Parkinson-White syndrome, Conclusion. A Wolff-Parkinson-White Syndrome may mimic a conduction disease. No reliable algorithm exists for making an ECG diagnosis of a preexcitation syndrome with conduction disorders. This can lead to diagnostic and therapeutic dilemmas in the context of syncope.

Detection of inter-patient left and right bundle branch block heartbeats in ECG using ensemble classifiers

PubMed Central

2014-01-01

Background Left bundle branch block (LBBB) and right bundle branch block (RBBB) not only mask electrocardiogram (ECG) changes that reflect diseases but also indicate important underlying pathology. The timely detection of LBBB and RBBB is critical in the treatment of cardiac diseases. Inter-patient heartbeat classification is based on independent training and testing sets to construct and evaluate a heartbeat classification system. Therefore, a heartbeat classification system with a high performance evaluation possesses a strong predictive capability for unknown data. The aim of this study was to propose a method for inter-patient classification of heartbeats to accurately detect LBBB and RBBB from the normal beat (NORM). Methods This study proposed a heartbeat classification method through a combination of three different types of classifiers: a minimum distance classifier constructed between NORM and LBBB; a weighted linear discriminant classifier between NORM and RBBB based on Bayesian decision making using posterior probabilities; and a linear support vector machine (SVM) between LBBB and RBBB. Each classifier was used with matching features to obtain better classification performance. The final types of the test heartbeats were determined using a majority voting strategy through the combination of class labels from the three classifiers. The optimal parameters for the classifiers were selected using cross-validation on the training set. The effects of different lead configurations on the classification results were assessed, and the performance of these three classifiers was compared for the detection of each pair of heartbeat types. Results The study results showed that a two-lead configuration exhibited better classification results compared with a single-lead configuration. The construction of a classifier with good performance between each pair of heartbeat types significantly improved the heartbeat classification performance. The results showed a sensitivity of 91.4% and a positive predictive value of 37.3% for LBBB and a sensitivity of 92.8% and a positive predictive value of 88.8% for RBBB. Conclusions A multi-classifier ensemble method was proposed based on inter-patient data and demonstrated a satisfactory classification performance. This approach has the potential for application in clinical practice to distinguish LBBB and RBBB from NORM of unknown patients. PMID:24903422

Detection of inter-patient left and right bundle branch block heartbeats in ECG using ensemble classifiers.

PubMed

Huang, Huifang; Liu, Jie; Zhu, Qiang; Wang, Ruiping; Hu, Guangshu

2014-06-05

Left bundle branch block (LBBB) and right bundle branch block (RBBB) not only mask electrocardiogram (ECG) changes that reflect diseases but also indicate important underlying pathology. The timely detection of LBBB and RBBB is critical in the treatment of cardiac diseases. Inter-patient heartbeat classification is based on independent training and testing sets to construct and evaluate a heartbeat classification system. Therefore, a heartbeat classification system with a high performance evaluation possesses a strong predictive capability for unknown data. The aim of this study was to propose a method for inter-patient classification of heartbeats to accurately detect LBBB and RBBB from the normal beat (NORM). This study proposed a heartbeat classification method through a combination of three different types of classifiers: a minimum distance classifier constructed between NORM and LBBB; a weighted linear discriminant classifier between NORM and RBBB based on Bayesian decision making using posterior probabilities; and a linear support vector machine (SVM) between LBBB and RBBB. Each classifier was used with matching features to obtain better classification performance. The final types of the test heartbeats were determined using a majority voting strategy through the combination of class labels from the three classifiers. The optimal parameters for the classifiers were selected using cross-validation on the training set. The effects of different lead configurations on the classification results were assessed, and the performance of these three classifiers was compared for the detection of each pair of heartbeat types. The study results showed that a two-lead configuration exhibited better classification results compared with a single-lead configuration. The construction of a classifier with good performance between each pair of heartbeat types significantly improved the heartbeat classification performance. The results showed a sensitivity of 91.4% and a positive predictive value of 37.3% for LBBB and a sensitivity of 92.8% and a positive predictive value of 88.8% for RBBB. A multi-classifier ensemble method was proposed based on inter-patient data and demonstrated a satisfactory classification performance. This approach has the potential for application in clinical practice to distinguish LBBB and RBBB from NORM of unknown patients.

Conduction Abnormalities and Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement Using the Repositionable LOTUS Device: The United Kingdom Experience.

PubMed

Rampat, Rajiv; Khawaja, M Zeeshan; Hilling-Smith, Roland; Byrne, Jonathan; MacCarthy, Philip; Blackman, Daniel J; Krishnamurthy, Arvindra; Gunarathne, Ashan; Kovac, Jan; Banning, Adrian; Kharbanda, Raj; Firoozi, Sami; Brecker, Stephen; Redwood, Simon; Bapat, Vinayak; Mullen, Michael; Aggarwal, Suneil; Manoharan, Ganesh; Spence, Mark S; Khogali, Saib; Dooley, Maureen; Cockburn, James; de Belder, Adam; Trivedi, Uday; Hildick-Smith, David

2017-06-26

The authors report the incidence of pacemaker implantation up to hospital discharge and the factors influencing pacing rate following implantation of the LOTUS bioprosthesis (Boston Scientific, Natick, Massachusetts) in the United Kingdom. Transcatheter aortic valve replacement (TAVR) is associated with a significant need for permanent pacemaker implantation. Pacing rates vary according to the device used. The REPRISE II (Repositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System) trial reported a pacing rate of 29% at 30 days after implantation of the LOTUS device. Data were collected retrospectively on 228 patients who had the LOTUS device implanted between March 2013 and February 2015 across 10 centers in the United Kingdom. Twenty-seven patients (12%) had pacemakers implanted pre-procedure and were excluded from the analysis. Patients were aged 81.2 ± 7.7 years; 50.7% were male. The mean pre-procedural QRS duration was 101.7 ± 20.4 ms. More than one-half of the cohort (n = 111, 55%) developed new left bundle branch block (LBBB) following the procedure. Permanent pacemakers were implanted in 64 patients (32%) with a median time to insertion of 3.0 ± 3.4 days. Chief indications for pacing were atrioventricular (AV) block (n = 46, 72%), or LBBB with 1st degree AV block (n = 11, 17%). Amongst those who received a pacemaker following TAVR the pre-procedural electrocardiogram findings included: No conduction disturbance (n = 41, 64%); 1st degree AV block (n = 10, 16%); right bundle branch block (n = 6, 9%) and LBBB (n = 5, 8%). LBBB (but not permanent pacemaker) occurred more frequently in patients who had balloon aortic valvuloplasty before TAVR (odds ratio [OR]: 1.25; p = 0.03). Pre-procedural conduction abnormality (composite of 1st degree AV block, hemiblock, right bundle branch block, LBBB) was independently associated with the need for permanent pacemaker (OR: 2.54; p = 0.048). The absence of aortic valve calcification was also associated with a higher pacing rate (OR: 0.55; p = 0.031). Multivariate regression analysis did not show an independent association between depth of implant, valve oversizing, balloon post-dilatation, and the need for pacing post-procedure. Following implantation of the repositionable LOTUS valve, 55% of patients developed LBBB and 32% of patients required a pacemaker during their index hospital admission. Patients with pre-procedural conduction disturbance and non-calcified aortic valves were more likely to need pacing. No other anatomic features were identified with increased pacing requirement with the LOTUS device. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Analysis of Morphological Characteristics and Origins of Idiopathic Premature Ventricular Contractions Under a 12-Lead Electrocardiogram in Children with Structurally Normal Hearts.

PubMed

Jiang, Jianbin; He, Yuee; Qiu, Huixian; Zhang, Yuanhai; Chu, Maoping; Li, Yuechun; Chen, Qi

2017-10-21

Up to 40% of healthy children have premature ventricular complexes or contractions (PVCs) detected with 24-hour Holter monitoring. We aimed to investigate the morphological characteristics and origins of idiopathic PVCs under a 12-lead electrocardiogram in children with structurally normal hearts. All asymptomatic monomorphic PVC patients with structurally normal hearts under 18 years of age were included in this retrospective study. Characteristics of PVCs in lead V 1 under a 12-lead electrocardiogram were classified as left bundle branch block (PVC-LBBB) or right bundle branch block (PVC-RBBB). According to limb leads, PVC-LBBB or PVC-RBBB was divided into: PVCs-LBBB type I; PVCs-LBBB type II; PVCs-RBBB type I; PVCs-RBBB type II; and PVCs-RBBB type III. Out of 178 PVC patients, 94 cases of PVCs-LBBB (PVCs-LBBB type I = 60; PVCs-LBBB type II = 34) and 84 cases of PVCs-RBBB (PVCs-RBBB type I = 3; PVCs-RBBB type II = 55; PVCs-RBBB type III = 26) were identified. The frequency of PVCs-LBBB type I increased with age and the frequency of PVCs-RBBB type II and III decreased with age. Among the children monitor tested, from 1 years old to 18 years old, PVCs originating from the left or right ventricular outflow tract gradually increased with age, while PVCs originating from the branch sources decreased with age.

Short- and long-term need for permanent pacemaker after transcatheter implantation of the Edwards Sapien aortic valve prosthesis.

PubMed

Moreno, Raúl; Calvo, Luis; Sánchez-Recalde, Angel; Galeote, Guillermo; Jiménez-Valero, Santiago; López, Teresa; Plaza, Ignacio; González-Davia, Rosa; Ramírez, Ulises; Mesa, Jose Maria; Moreno-Gomez, Isidro; López-Sendón, José-Luis

2015-11-01

A permanent pacemaker is frequently needed after transcatheter aortic valve implantation, but the available data are mainly on the CoreValve system. To evaluate the need for new permanent pacemaker after implantation of the Edwards Sapien device, as well as related factors. We included the first 100 patients treated with the Edwards Sapien device at our institution. Of these, 12 had a permanent pacemaker before the procedure, and thus our study population was the remaining 88 patients. A permanent pacemaker was indicated in eight patients (9.1%) during hospitalization or at 30 days. After discharge, another four patients needed a pacemaker (at 42 days and three, 18, and 30 months). Two variables were associated with the need for pacemaker during hospitalization: previous dialysis (13% vs. 1%, p=0.042) and complete right bundle branch block before the procedure (25% vs. 5%, p=0.032). More than one month after the procedure, the characteristics associated with the need for pacemaker were plasma creatinine level (2.5±1.7 vs. 1.3±0.6 mg/dl, p=0.001) and previous myocardial infarction (50% vs. 10%, p=0.013). The rate of pacemaker implantation with the Edwards Sapien device was 9.1%. Right bundle branch block and dialysis were associated with this complication.

The Prognostic Impact of New-Onset Persistent Left Bundle Branch Block Following Transcatheter Aortic Valve Implantation: A Meta-analysis.

PubMed

Ando, Tomo; Takagi, Hisato

2016-09-01

New-onset persistent left bundle branch block (NOP-LBBB) is one of the most common conduction disturbances after transcatheter aortic valve implantation (TAVI). We hypothesized that NOP-LBBB may have a clinically negative impact after TAVI. To find out, we conducted a systematic literature search of the MEDLINE/PubMed and Embase databases. Observational studies that reported clinical outcomes of NOP-LBBB patients after TAVI were included. The random-effects model was used to combine odds ratios, risk ratios, or hazard ratios (HRs) with 95% confidence intervals. Adjusted HRs were utilized over unadjusted HRs or risk ratios when available. A total of 4049 patients (807 and 3242 patients with and without NOP-LBBB, respectively) were included. Perioperative (in-hospital or 30-day) and midterm all-cause mortality and midterm cardiovascular mortality were comparable between the groups. The NOP-LBBB patients experienced a higher rate of permanent pacemaker implantation (HR: 2.09, 95% confidence interval: 1.12-3.90, P = 0.021, I(2) = 83%) during midterm follow-up. We found that NOP-LBBB after TAVI resulted in higher permanent pacemaker implantation but did not negatively affect the midterm prognosis. Therefore, careful observation during the follow-up is required. © 2016 Wiley Periodicals, Inc.

[Early complications following transcatheter occlusion of perimembranous ventricular septal defects in children].

PubMed

Li, Jun-jie; Zhang, Zhi-wei; Qian, Ming-yang; Wang, Hui-shen; Li, Yu-fen

2006-11-01

To evaluate the early complications during and after transcatheter closure of perimembranous ventricular septal defects (PMVSDs) in children. A total of 223 patients received transcatheter closure of PMVSDs from March 2002 to December 2005 in our hospital were included in this retrospective study. The overall complications rate was 26.9% (60/223). Major complications occurred in 9 patients (4.0%) including III degrees atrioventricular block (AVB) in 2 (0.9%), hemolysis in 3 (1.3%) and surgical interventions in 4 patients (1.8%) because of device malposition (1), mild aortic regurgitation (2) and device embolization (1) and all 4 patients recovered without further complications. The 2 patients with III degrees AVB were completely recovered to normal sinus rhythm after 7 days treatment with temporary pacemaker and corticosteroid. Hemolysis in 3 patients disappeared after corticosteroid treatment. Minor complications occurred in 51 patients (22.8%) including bundle branch block (BBB) in 37 (16.6%), first-degree AVB in 2 (0.9%), second-degree AVB in 1 (0.4%), new-onset mild aortic regurgitation in 5 (2.2%) and new-onset mild to moderate tricuspid regurgitation in 6 patients (2.6%). Except for right bundle branch blocks, other BBBs were treated with albumin and corticosteroid and completely recovered. No treatment was applied for new-onset valve regurgitations. There was no death in all 223 patients. Early complications post PMVSDs in children are mostly minor with good prognosis and the prognosis for major complications post PMVSDs is good after proper treatment.

Anatomy of Atrioventricular Node Artery and Pattern of Dominancy in Normal Coronary Subject: A Comparison between Individuals with and without Isolated Right Bundle Branch Block

PubMed Central

Kazemisaeid, Ali; Pakbaz, Marziyeh; Yaminisharif, Ahmad; Davoodi, Gholamreza; Lotfi Tokaldany, Masoumeh; Hakki Kazazi, Elham

2012-01-01

Background: Isolated right bundle branch block (RBBB) is a common finding in the general population. The atrioventricular node (AVN) artery contributes to the blood supply of the right bundle branch. Our hypothesis was that the anatomy of the AVN artery and the pattern of dominancy differ between subjects with and without RBBB. Methods: We retrospectively studied the coronary angiography of 92 patients with RBBB and 184 age- and gender-matched controls without RBBB. All the subjects had angiographically proven normal coronary arteries. The dominant circulation and precise origin of the AVN artery were determined in each subject. Obtained data were compared between the two study groups. Results: There was no significant difference between the two groups in terms of dominancy (p value = 0.200). Origination of the AVN artery from the right circulatory system was more common in both groups, but this pattern was more prevalent in the cases than in the controls (p value = 0.021). There was a great variation of the AVN artery origin. In the total study population, the AVN artery was more commonly separated from a non crux origin than from the crux area. The prevalence of the non-crux origination of the AVN artery was significantly higher in the cases than in the controls (p value < 0.001). While the origination of the AVN artery from the right circulatory system was more common in both groups, the prevalence of the right origin of the AVN artery was significantly higher in the cases than in the controls. We observed that the AVN artery most commonly originated from the dominant artery but not necessarily from the crux. Conclusion: The anatomy of the AVN artery but not the pattern of dominancy is somewhat different in subjects with RBBB compared with normal individuals. PMID:23323077

Anatomy of Atrioventricular Node Artery and Pattern of Dominancy in Normal Coronary Subject: A Comparison between Individuals with and without Isolated Right Bundle Branch Block.

PubMed

Kazemisaeid, Ali; Pakbaz, Marziyeh; Yaminisharif, Ahmad; Davoodi, Gholamreza; Lotfi Tokaldany, Masoumeh; Hakki Kazazi, Elham

2012-11-01

Isolated right bundle branch block (RBBB) is a common finding in the general population. The atrioventricular node (AVN) artery contributes to the blood supply of the right bundle branch. Our hypothesis was that the anatomy of the AVN artery and the pattern of dominancy differ between subjects with and without RBBB. We retrospectively studied the coronary angiography of 92 patients with RBBB and 184 age- and gender-matched controls without RBBB. All the subjects had angiographically proven normal coronary arteries. The dominant circulation and precise origin of the AVN artery were determined in each subject. Obtained data were compared between the two study groups. There was no significant difference between the two groups in terms of dominancy (p value = 0.200). Origination of the AVN artery from the right circulatory system was more common in both groups, but this pattern was more prevalent in the cases than in the controls (p value = 0.021). There was a great variation of the AVN artery origin. In the total study population, the AVN artery was more commonly separated from a non crux origin than from the crux area. The prevalence of the non-crux origination of the AVN artery was significantly higher in the cases than in the controls (p value < 0.001). While the origination of the AVN artery from the right circulatory system was more common in both groups, the prevalence of the right origin of the AVN artery was significantly higher in the cases than in the controls. We observed that the AVN artery most commonly originated from the dominant artery but not necessarily from the crux. The anatomy of the AVN artery but not the pattern of dominancy is somewhat different in subjects with RBBB compared with normal individuals.

Complications with the MICRA TPS Pacemaker System: Persistent Complete Heart Block and Late Capture Failure.

PubMed

Holm, Niels; Müller, Andreas; Zbinden, Rainer

2017-04-01

A Medtronic MICRA transcatheter pacing system (Medtronic, Minneapolis, MN, USA) was implanted in an 86-year-old patient with sick sinus syndrome and left bundle branch block after transfemoral aortic valve implantation. During implantation she developed a persistent complete heart block due to manipulation with the large-bore delivery catheter. Two weeks later, acute pacemaker dysfunction occurred due to massive increase of pacing threshold and impedance without obvious pacemaker dislocation or myocardial perforation. Recurrent capture failure was seen with pacing output set at 5 V/1.0 ms. Hence, microdislocation or fixation of the tines in the right ventricular trabeculae has to be assumed. © 2016 Wiley Periodicals, Inc.

Wolff-Parkinson-White Syndrome Mimics a Conduction Disease

PubMed Central

Marrakchi, S.; Kammoun, I.; Kachboura, S.

2014-01-01

Background. It is important to recognise Wolff-Parkinson-White (WPW) syndrome in electrocardiograms (ECG), as it may mimic ischaemic heart disease, ventricular hypertrophy, and bundle branch block. Recognising WPW syndrome allows for risk stratification, the identification of associated conditions, and the institution of appropriate management. Objective. The present case showed that electrophysiological study is indicated in patients with abnormal ECG and syncope. Case Report. A 40-year-old man with Wolff-Parkinson-White syndrome was presented to emergency with syncope. A baseline ECG was a complete right branch block and posterior left hemiblock. He was admitted to the cardiac care unit for pacemaker implantation. The atypical figure of complete right branch block and posterior left hemiblock was thought to be a “false positive” of conduction abnormality. But the long anterograde refractory period of the both accessory pathway and atrioventricular conduction may cause difficulty in diagnosing Wolff-Parkinson-White syndrome, Conclusion. A Wolff-Parkinson-White Syndrome may mimic a conduction disease. No reliable algorithm exists for making an ECG diagnosis of a preexcitation syndrome with conduction disorders. This can lead to diagnostic and therapeutic dilemmas in the context of syncope. PMID:25114686

A Clinical and Follow-up Study of Right and Left Bundle Branch Block

DTIC Science & Technology

1974-09-03

atrial septal defects, one with a patent dnctus arteriosns. and one with coarctation of the aorta and aortic stenosis ), one case of rheumatic heart...disease with mild mitral and aortic insufficiency, one case of documented myocarditis, and two cases of nonrheumatic hemodynamiially in- Tuhle 3 .Si...f,’r(»i/() Aniiltjsi\\ of Clinical Evahtotion in EliliB Stihjcrts significant mitral insufficiency. Since some of the ECG subgroups

Right bundle branch block without overt heart disease predicts higher risk of pacemaker implantation: the study of atomic-bomb survivors.

PubMed

Kusumoto, Saburo; Kawano, Hiroaki; Makita, Naomasa; Ichimaru, Shinichiro; Kaku, Takashi; Haruta, Daisuke; Hida, Ayumi; Sera, Nobuko; Imaizumi, Misa; Nakashima, Eiji; Maemura, Koji; Akahoshi, Masazumi

2014-06-01

We investigated the clinical course of complete right bundle branch block (RBBB) or RBBB with axis deviation (AD) in terms of subsequent pacemaker implantation for high-degree atrioventricular (AV) block or sick sinus syndrome (SSS). Among the 16,170 atomic-bomb survivors in our biennial health examination between July 1967 and December 2010, we detected 520 newly-acquired RBBB subjects with no organic heart disease, and selected 1038 age- (at RBBB diagnosis) and sex-matched subjects without RBBB to serve as comparison subjects. Multivariate Cox regression analysis was used to estimate the hazard ratios (HRs) for the risk of pacemaker implantation due to all causes, AV block or SSS between RBBB and comparison subjects and between RBBB subjects with and without AD. The risk of pacemaker implantation for RBBB was 4.79 (95% confidence interval [CI] 1.89-12.58; P=0.001), 3.77 (95% CI, 1.09-13.07; P=0.036), and 6.28 (95% CI, 1.24-31.73, P=0.026) when implantation was for all causes, AV block and SSS, respectively. RBBB subjects with AD had a higher risk for all-cause pacemaker implantation than subjects without AD (HR, 3.03; 95% CI, 1.00-9.13, P=0.049). RBBB subjects with AD were younger than subjects without AD at the time of RBBB diagnosis (59.4±7.6 vs 74.4±3.1 years old, P=0.019), and their progression from diagnosis to pacemaker implantation took longer (15.1±6.6 vs 6.4±3.0 years, P=0.032). RBBB, especially with AD, progresses to AV block and SSS that requires pacemaker implantation; the mechanisms by which the conduction defect progresses differ among patients with and without AD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Diagnosis and ablation of multiform fascicular tachycardia.

PubMed

Sung, Raphael K; Kim, Albert M; Tseng, Zian H; Han, Frederick; Inada, Keiichi; Tedrow, Usha B; Viswanathan, Mohan N; Badhwar, Nitish; Varosy, Paul D; Tanel, Ronn; Olgin, Jeffrey E; Stephenson, William G; Scheinman, Melvin

2013-03-01

Fascicular tachycardia (FT) is an uncommon cause of monomorphic sustained ventricular tachycardia (VT). We describe 6 cases of FT with multiform QRS morphologies. Six of 823 consecutive VT cases were retrospectively analyzed and found attributable to FT with multiform QRS patterns, with 3 cases exhibiting narrow QRS VT as well. All underwent electrophysiology study including fascicular potential mapping, entrainment pacing, and electroanatomic mapping. The first 3 cases describe similar multiform VT patterns with successful ablation in the upper mid septum. Initially, a right bundle branch block (RBBB) VT with superior axis was induced. Radiofrequency catheter ablation (RFCA) targeting the left posterior fascicle (LPF) resulted in a second VT with RBBB inferior axis. RFCA in the upper septum just apical to the LBB potential abolished VT in all cases. Cases 4 and 5 showed RBBB VT with alternating fascicular block compatible with upper septal dependent VT, resulting in bundle branch reentrant VT (BBRT) after ablation of LPF and left anterior fascicle (LAF). Finally, Cases 5 and 6 demonstrated spontaneous shift in QRS morphology during VT, implicating participation of a third fascicle. In Case 6, successful ablation was achieved over the proximal LAF, likely representing insertion of the auxiliary fascicle near the proximal LAF. Multiform FTs show a reentrant mechanism using multiple fascicular branches. We hypothesize that retrograde conduction over the septal fascicle produces alternate fascicular patterns as well as narrow VT forms. Ablation of the respective fascicle was successful in abolishing FT but does not preclude development of BBRT unless septal fascicle is targeted and ablated. © 2012 Wiley Periodicals, Inc.

CLINICAL AND EPIDEMIOLOGICAL PROFILE OF ELDERLY PATIENTS WITH CHAGAS DISEASE FOLLOWED BETWEEN 2005-2013 BY PHARMACEUTICAL CARE SERVICE IN CEARÁ STATE, NORTHEASTERN BRAZIL

PubMed Central

PEREIRA, Laíse dos Santos; FREITAS, Erlane Chaves; FIDALGO, Arduína Sofia Ortet de Barros Vasconcelos; ANDRADE, Mônica Coelho; CÂNDIDO, Darlan da Silva; da SILVA, José Damião; MICHAILOWSKY, Vladimir; OLIVEIRA, Maria de Fátima; QUEIROZ, José Ajax Nogueira

2015-01-01

By controlling the transmission of Chagas disease, the challenge of providing assistance to millions of infected patients that reach old age arises. In this study, the socioeconomic, demographic and comorbidity records of all elderly chagasic patients followed at the Pharmaceutical Care Service of the Chagas Disease Research Laboratory were assessed. The information related to the clinical form of the disease was obtained from medical records provided by the Walter Cantídio University Hospital. The profile of the studied population was: women (50.5%); mean age of 67 years; retired (54.6%); married (51.6 %); high illiteracy rate (40.2%); and family income equal to the minimum wage (51.5%). The predominant clinical forms of Chagas disease were cardiac (65.3%) and indeterminate (14.7%). The main electrocardiographic changes were the right bundle branch block (41.0%), associated or not with the anterosuperior left bundle branch block (27.4%). The average number of comorbidities per patient was 2.23 ± 1.54, with systemic arterial hypertension being the main one found (67.0%). It was found that the elderly comprise a vulnerable group of patients that associate aging with cardiac and/or digestive disorders resulting from the evolution of Chagas disease and other comorbidities, which requires special attention from health services to ensure more appropriate medical and social care. PMID:25923894

Hemodynamic Improvement in Cardiac Resynchronization Does Not Require Improvement in Left Ventricular Rotation Mechanics

PubMed Central

Ashikaga, Hiroshi; Leclercq, Christophe; Wang, Jiangxia; Kass, David A.; McVeigh, Elliot R.

2010-01-01

Background Earlier studies have yielded conflicting evidence on whether or not cardiac resynchronization therapy (CRT) improves left ventricular (LV) rotation mechanics. Methods and Results In dogs with left bundle branch block and pacing-induced heart failure (n=7), we studied the effects of CRT on LV rotation mechanics in vivo by 3-dimensional tagged magnetic resonance imaging with a temporal resolution of 14 ms. CRT significantly improved hemodynamic parameters but did not significantly change the LV rotation or rotation rate. LV torsion, defined as LV rotation of each slice with respect to that of the most basal slice, was not significantly changed by CRT. CRT did not significantly change the LV torsion rate. There was no significant circumferential regional heterogeneity (anterior, lateral, inferior, and septal) in LV rotation mechanics in either left bundle branch block with pacing-induced heart failure or CRT, but there was significant apex-to-base regional heterogeneity. Conclusions CRT acutely improves hemodynamic parameters without improving LV rotation mechanics. There is no significant circumferential regional heterogeneity of LV rotation mechanics in the mechanically dyssynchronous heart. These results suggest that LV rotation mechanics is an index of global LV function, which requires coordination of all regions of the left ventricle, and improvement in LV rotation mechanics appears to be a specific but insensitive index of acute hemodynamic response to CRT. PMID:20478988

Analysis of electrocardiogram in chronic obstructive pulmonary disease patients.

PubMed

Lazović, Biljana; Svenda, Mirjana Zlatković; Mazić, Sanja; Stajić, Zoran; Delić, Marina

2013-01-01

Chronic obstructive pulmonary disease is the fourth leading cause of mortality worldwide. It is defined as a persistent airflow limitation usually progressive and not fully reversible to treatment. The diagnosis of chronic obstructive pulmonary disease and severity of disease is confirmed by spirometry. Chronic obstructive pulmonary disease produces electrical changes in the heart which shows characteristic electrocardiogram pattern. The aim of this study was to observe and evaluate diagnostic values of electrocardiogram changes in chronic obstructive pulmonary disease patients with no other comorbidity. We analyzed 110 electrocardiogram findings in clinically stable chronic obstructive pulmonary disease patients and evaluated the forced expiratory volume in the first second, ratio of forces expiratory volume in the first second to the fixed vital capacity, chest radiographs and electrocardiogram changes such as p wave height, QRS axis and voltage, right bundle branch block, left bundle branch block, right ventricular hypertrophy, T wave inversion in leads V1-V3, S1S2S3 syndrome, transition zone in praecordial lead and QT interval. We found electrocardiogram changes in 64% patients, while 36% had normal electrocardiogram. The most frequent electrocardiogram changes observed were transition zone (76.36%) low QRS (50%) and p pulmonale (14.54%). Left axis deviation was observed in 27.27% patients. Diagnostic values of electrocardiogram in patients with chronic obstructive pulmonary disease suggest that chronic obstructive pulmonary disease patients should be screened electrocardiographically in addition to other clinical investigations.

A novel wavelet sequence based on deep bidirectional LSTM network model for ECG signal classification.

PubMed

Yildirim, Özal

2018-05-01

Long-short term memory networks (LSTMs), which have recently emerged in sequential data analysis, are the most widely used type of recurrent neural networks (RNNs) architecture. Progress on the topic of deep learning includes successful adaptations of deep versions of these architectures. In this study, a new model for deep bidirectional LSTM network-based wavelet sequences called DBLSTM-WS was proposed for classifying electrocardiogram (ECG) signals. For this purpose, a new wavelet-based layer is implemented to generate ECG signal sequences. The ECG signals were decomposed into frequency sub-bands at different scales in this layer. These sub-bands are used as sequences for the input of LSTM networks. New network models that include unidirectional (ULSTM) and bidirectional (BLSTM) structures are designed for performance comparisons. Experimental studies have been performed for five different types of heartbeats obtained from the MIT-BIH arrhythmia database. These five types are Normal Sinus Rhythm (NSR), Ventricular Premature Contraction (VPC), Paced Beat (PB), Left Bundle Branch Block (LBBB), and Right Bundle Branch Block (RBBB). The results show that the DBLSTM-WS model gives a high recognition performance of 99.39%. It has been observed that the wavelet-based layer proposed in the study significantly improves the recognition performance of conventional networks. This proposed network structure is an important approach that can be applied to similar signal processing problems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrocardiographic abnormalities in Trypanosoma cruzi seropositive and seronegative former blood donors.

PubMed

Ribeiro, Antonio L; Sabino, Ester C; Marcolino, Milena S; Salemi, Vera M C; Ianni, Barbara M; Fernandes, Fábio; Nastari, Luciano; Antunes, André; Menezes, Márcia; Oliveira, Cláudia Di Lorenzo; Sachdev, Vandana; Carrick, Danielle M; Busch, Michael P; Murphy, Eduard L

2013-01-01

Blood donor screening leads to large numbers of new diagnoses of Trypanosoma cruzi infection, with most donors in the asymptomatic chronic indeterminate form. Information on electrocardiogram (ECG) findings in infected blood donors is lacking and may help in counseling and recognizing those with more severe disease. To assess the frequency of ECG abnormalities in T.cruzi seropositive relative to seronegative blood donors, and to recognize ECG abnormalities associated with left ventricular dysfunction. The study retrospectively enrolled 499 seropositive blood donors in São Paulo and Montes Claros, Brazil, and 483 seronegative control donors matched by site, gender, age, and year of blood donation. All subjects underwent a health clinical evaluation, ECG, and echocardiogram (Echo). ECG and Echo were reviewed blindly by centralized reading centers. Left ventricular (LV) dysfunction was defined as LV ejection fraction (EF)<0.50%. Right bundle branch block and left anterior fascicular block, isolated or in association, were more frequently found in seropositive cases (p<0.0001). Both QRS and QTc duration were associated with LVEF values (correlation coefficients -0.159,p<0.0003, and -0.142,p = 0.002) and showed a moderate accuracy in the detection of reduced LVEF (area under the ROC curve: 0.778 and 0.790, both p<0.0001). Several ECG abnormalities were more commonly found in seropositive donors with depressed LVEF, including rhythm disorders (frequent supraventricular ectopic beats, atrial fibrillation or flutter and pacemaker), intraventricular blocks (right bundle branch block and left anterior fascicular block) and ischemic abnormalities (possible old myocardial infarction and major and minor ST abnormalities). ECG was sensitive (92%) for recognition of seropositive donors with depressed LVEF and had a high negative predictive value (99%) for ruling out LV dysfunction. ECG abnormalities are more frequent in seropositive than in seronegative blood donors. Several ECG abnormalities may help the recognition of seropositive cases with reduced LVEF who warrant careful follow-up and treatment.

Bundle-branch reentry ventricular tachycardia after transcatheter aortic valve replacement

PubMed Central

de la Rosa Riestra, Adriana; Rubio Caballero, José Amador; Freites Estévez, Alfonso; Alonso Belló, Javier; Botas Rodríguez, Javier

2016-01-01

An 83-year-old male suffering from severe symptomatic aortic valve stenosis received an implant of a biological aortic prosthesis through the femoral artery without complications. Seven days after dischargement he experienced a syncope. The patient was wearing an ECG holter monitor that day, which showed a wide QRS complex tachycardia of 300 beats per minute. The electrophysiological study revealed a bundle-branch reentry ventricular tachycardia as the cause of the syncope. Radio-frequency was applied on the right-bundle branch. Twelve months later, the patient has remained asymptomatic. PMID:27134443

ECG findings in comparison to cardiovascular MR imaging in viral myocarditis.

PubMed

Deluigi, Claudia C; Ong, Peter; Hill, Stephan; Wagner, Anja; Kispert, Eva; Klingel, Karin; Kandolf, Reinhard; Sechtem, Udo; Mahrholdt, Heiko

2013-04-30

We sought (1) to assess prevalence and type of ECG abnormalities in patients with biopsy proven myocarditis and signs of myocardial damage indicated by LGE, and (2) to evaluate whether ECG abnormalities are related to the pattern of myocardial damage. Prevalence and type of ECG abnormalities in patients presenting biopsy proven myocarditis, as well as any relation between ECG abnormalities and the in vivo pattern of myocardial damage are unknown. Eighty-four consecutive patients fulfilled the following criteria: (1) newly diagnosed biopsy proven viral myocarditis, and (2) non-ischemic LGE, and (3) standard 12-lead-ECG upon admission. Sixty-five patients with biopsy proven myocarditis had abnormal ECGs upon admission (77%). In this group, ST-abnormalities were detected most frequently (69%), followed by bundle-branch-block in 26%, and Q-waves in 8%. Atrial fibrillation was present in 6%, and AV-Block in two patients. In patients with septal LGE ST-abnormalities were more frequently located in anterolateral leads compared to patients with lateral LGE, in whom ST-abnormalities were most frequently observed in inferolateral leads. Bundle-branch-block occurred more often in patients with septal LGE (11/17). Four of five patients with Q-waves had severe and almost transmural LGE in the lateral wall. ECG abnormalities can be found in most patients with biopsy proven viral myocarditis at initial presentation. However, similar to suspected acute myocardial infarction, a normal ECG does not rule out myocarditis. ECG findings are related to the amount and area of damage as indicated by LGE, which confirms the important clinical role of ECG. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Prevalence of Chagas Disease in a U.S. Population of Latin American Immigrants with Conduction Abnormalities on Electrocardiogram

PubMed Central

Hernandez, Salvador; Sanchez, Daniel R.; Dufani, Jalal; Salih, Mohsin; Abuhamidah, Adieb M.; Olmedo, Wilman; Bradfield, Jason S.; Forsyth, Colin J.; Meymandi, Sheba K.

2017-01-01

Chagas disease (CD) affects over six million people and is a leading cause of cardiomyopathy in Latin America. Given recent migration trends, there is a large population at risk in the United States (US). Early stage cardiac involvement from CD usually presents with conduction abnormalities on electrocardiogram (ECG) including right bundle branch block (RBBB), left anterior or posterior fascicular block (LAFB or LPFB, respectively), and rarely, left bundle branch block (LBBB). Identification of disease at this stage may lead to early treatment and potentially delay the progression to impaired systolic function. All ECGs performed in a Los Angeles County hospital and clinic system were screened for the presence of RBBB, LAFB, LPFB, or LBBB. Patients were contacted and enrolled in the study if they had previously resided in Latin America for at least 12 months and had no history of cardiac disease. Enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA) tests were utilized to screen for Trypanosoma cruzi seropositivity. A total of 327 consecutive patients were screened for CD from January 2007 to December 2010. The mean age was 46.3 years and the mean length of stay in the US was 21.2 years. Conduction abnormalities were as follows: RBBB 40.4%, LAFB 40.1%, LPFB 2.8%, LBBB 5.5%, RBBB and LAFB 8.6%, and RBBB and LPFB 2.8%. Seventeen patients were positive by both ELISA and IFA (5.2%). The highest prevalence rate was among those with RBBB and LAFB (17.9%). There is a significant prevalence of CD in Latin American immigrants residing in Los Angeles with conduction abnormalities on ECG. Clinicians should consider evaluating all Latin American immigrant patients with unexplained conduction disease for CD. PMID:28056014

[Electrocardiographic abnormalities in acute olanzapine poisonings].

PubMed

Ciszowski, Krzysztof; Sein Anand, Jacek

2011-01-01

Olanzapine is an atypical antipsychotic used for many years in the treatment of schizophrenia and bipolar disorder. Poisonings with this medicine can results with cardiotoxic effects in the form of ECG abnormalities. To evaluate the nature and incidence of electrocardiographic abnormalities in patients with acute olanzapine poisoning. 23 adult (mean age 38.4 +/- 15.5 years) patients with acute olanzapine poisoning, including 10 men (30.4 +/- 8.1 years) and 11 women (45.7 +/- 17.2 years), where 1 man and 1 woman were poisoned twice. The toxic serum level of olanzapine (above 100 ng/mL) was confirmed in each patient. Evaluation of electrocardiograms performed in patients in the first day of hospitalization with automatic measurement of durations of PQ, QRS and QTc and the identification of arrhythmias and conduction disorders on the basis of visual analysis of the ECG waveforms. Statistical analysis of the results using the methods of descriptive statistics. The mean durations of PQ, QRS and QTc in the study group were as follows: 135 +/- 23 ms, 91 +/- 12 ms, and 453 +/- 48 ms, respectively. The most common ECG abnormalities were prolonged QTc and supraventricular tachycardia (including sinus tachycardia) - each 22%; less common were ST-T changes (17%) and supraventricular premature complexes (9%), and only in individual cases (4%) ventricular premature complexes, bundle branch block, sinus bradycardia and atrial fibrillation were present. In the course of acute olanzapine poisonings: (1) prolonged QTc interval is quite common, but rarely leads to torsade de pointes tachycardia; (2) fast supraventricular rhythms are also common, but rarely cause irregular tachyarrhythmias, eg. atrial fibrillation; (3) conduction disorders (atrioventricular blocks, bundle branch blocks) are not typical abnormalities; (4) the observed ECG abnormalities emphasize the need of continuous ECG monitoring in these patients.

QT prolongation and sudden cardiac death risk in hypertrophic cardiomyopathy.

PubMed

Patel, Salma I; Ackerman, Michael J; Shamoun, Fadi E; Geske, Jeffrey B; Ommen, Steve R; Love, William T; Cha, Stephen S; Bos, Johan M; Lester, Steven J

2018-03-07

Risk assessment for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) remains complex. The goal of this study was to assess electrocardiogram (ECG)-derived risk factors on SCD in a large HCM population Methods: Retrospective review of adults with HCM evaluated at Mayo Clinic, Rochester, MN from 1 December 2002 to 31 December 2012 was performed. Data inclusive of ECG and 24-hour ambulatory Holter monitor were assessed. SCD events were documented by ventricular fibrillation (VF) noted on implantable cardioverter defibrillator (ICD), or appropriate VT or VF-terminating ICD shock. Overall, 1615 patients (mean age 53.7 ± 15.2 years; 943 males, 58.4%) were assessed, with mean follow-up 2.46 years and 110 SCD events. Via logistic regression (n = 820), the odds of SCD increased with increasing number of conventional risk factors. With one risk factor the OR was 4.88 (p < .0001; CI 2.22-10.74), two risk factors the OR was 6.922 (p < .0001; CI 2.94-16.28) and three or more risk factors, the OR was 13.997 (p < .0001; CI 5.649-34.68). Adding QTc > 450 to this logistic regression model had OR 1.722 (p = .04, CI 1.01-2.937) to predict SCD. QTc ≥ 450 was a significant predictor for death (HR 1.88, p = .021, CI 1.10-3.20). There was no correlation between sinus bradycardia, sinus tachycardia, first degree AV block, atrial fibrillation, left bundle branch block, right bundle branch block, premature atrial complexes, premature ventricular complexes, supraventricular tachycardia, PR interval, QRS interval and SCD. Prolonged QTc was a risk factor for SCD and death even when controlling for typical risk factors.

Electrocardiogram findings in emergency department patients with syncope.

PubMed

Quinn, James; McDermott, Daniel

2011-07-01

To determine the sensitivity and specificity of the San Francisco Syncope Rule (SFSR) electrocardiogram (ECG) criteria for determining cardiac outcomes and to define the specific ECG findings that are the most important in patients with syncope. A consecutive cohort of emergency department (ED) patients with syncope or near syncope was considered. The treating emergency physicians assessed 50 predictor variables, including an ECG and rhythm assessment. For the ECG assessment, the physicians were asked to categorize the ECG as normal or abnormal based on any changes that were old or new. They also did a separate rhythm assessment and could use any of the ECGs or available monitoring strips, including prehospital strips, when making this assessment. All patients were followed up to determine a broad composite study outcome. The final ECG criterion for the SFSR was any nonsinus rhythm or new ECG changes. In this specific study, the initial assessments in the database were used to determine only cardiac-related outcomes (arrhythmia, myocardial infarction, structural, sudden death) based on set criteria, and the authors determined the sensitivity and specificity of the ECG criteria for cardiac outcomes only. All ECGs classified as "abnormal" by the study criteria were compared to the official cardiology reading to determine specific findings on the ECG. Univariate and multivariate analysis were used to determine important specific ECG and rhythm findings. A total of 684 consecutive patients were considered, with 218 having positive ECG criteria and 42 (6%) having important cardiac outcomes. ECG criteria predicted 36 of 42 patients with cardiac outcomes, with a sensitivity of 86% (95% confidence interval [CI] = 71% to 94%), a specificity of 70% (95% CI = 66% to 74%), and a negative predictive value of 99% (95% CI = 97% to 99%). Regarding specific ECG findings, any nonsinus rhythm from any source and any left bundle conduction problem (i.e., any left bundle branch block, left anterior fascicular block, left posterior fascicular block, or QRS widening) were 2.5 and 3.5 times more likely associated with significant cardiac outcomes. The ECG criteria from the SFSR are relatively simple, and if used correctly can help predict which patients are at risk of cardiac outcomes. Furthermore, any left bundle branch block conduction problems or any nonsinus rhythms found during the ED stay should be especially concerning for physicians caring for patients presenting with syncope. © 2011 by the Society for Academic Emergency Medicine.

Mechanistic insight into prolonged electromechanical delay in dyssynchronous heart failure: a computational study

PubMed Central

Constantino, Jason; Hu, Yuxuan; Lardo, Albert C.

2013-01-01

In addition to the left bundle branch block type of electrical activation, there are further remodeling aspects associated with dyssynchronous heart failure (HF) that affect the electromechanical behavior of the heart. Among the most important are altered ventricular structure (both geometry and fiber/sheet orientation), abnormal Ca2+ handling, slowed conduction, and reduced wall stiffness. In dyssynchronous HF, the electromechanical delay (EMD), the time interval between local myocyte depolarization and myofiber shortening onset, is prolonged. However, the contributions of the four major HF remodeling aspects in extending EMD in the dyssynchronous failing heart remain unknown. The goal of this study was to determine the individual and combined contributions of HF-induced remodeling aspects to EMD prolongation. We used MRI-based models of dyssynchronous nonfailing and HF canine electromechanics and constructed additional models in which varying combinations of the four remodeling aspects were represented. A left bundle branch block electrical activation sequence was simulated in all models. The simulation results revealed that deranged Ca2+ handling is the primary culprit in extending EMD in dyssynchronous HF, with the other aspects of remodeling contributing insignificantly. Mechanistically, we found that abnormal Ca2+ handling in dyssynchronous HF slows myofiber shortening velocity at the early-activated septum and depresses both myofiber shortening and stretch rate at the late-activated lateral wall. These changes in myofiber dynamics delay the onset of myofiber shortening, thus giving rise to prolonged EMD in dyssynchronous HF. PMID:23934857

A Clinical Feasibility Study of Atrial and Ventricular Electromechanical Wave Imaging

PubMed Central

Provost, Jean; Gambhir, Alok; Vest, John; Garan, Hasan; Konofagou, Elisa E.

2014-01-01

Background Cardiac Resynchronization Therapy (CRT) and atrial ablation currently lack a noninvasive imaging modality for reliable treatment planning and monitoring. Electromechanical Wave Imaging (EWI) is an ultrasound-based method that has previously been shown to be capable of noninvasively and transmurally mapping the activation sequence of the heart in animal studies by estimating and imaging the electromechanical wave, i.e., the transient strains occurring in response to the electrical activation, at both very high temporal and spatial resolution. Objective Demonstrate the feasibility of noninvasive transthoracic EWI for mapping the activation sequence during different cardiac rhythms in humans. Methods EWI was performed in CRT patients with a left bundle-branch block (LBBB), during sinus rhythm, left-ventricular pacing, and right-ventricular pacing and in atrial flutter (AFL) patients before intervention and correlated with results from invasive intracardiac electrical mapping studies during intervention. Additionally, the feasibility of single-heartbeat EWI at 2000 frames/s, is demonstrated in humans for the first time in a subject with both AFL and right bundle-branch-block. Results The electromechanical activation maps demonstrated the capability of EWI to localize the pacing sites and characterize the LBBB activation sequence transmurally in CRT patients. In AFL patients, the propagation patterns obtained with EWI were in agreement with results obtained from invasive intracardiac mapping studies. Conclusion Our findings demonstrate the potential capability of EWI to aid in monitoring and follow-up of patients undergoing CRT pacing therapy and atrial ablation with preliminary validation in vivo. PMID:23454060

Arrhythmogenic substrate at the interventricular septum as a target site for radiofrequency catheter ablation of recurrent ventricular tachycardia in left dominant arrhythmogenic cardiomyopathy.

PubMed

Havranek, Stepan; Palecek, Tomas; Kovarnik, Tomas; Vitkova, Ivana; Psenicka, Miroslav; Linhart, Ales; Wichterle, Dan

2015-03-10

Left dominant arrhythmogenic cardiomyopathy (LDAC) is a rare condition characterised by progressive fibrofatty replacement of the myocardium of the left ventricle (LV) in combination with ventricular arrhythmias of LV origin. A thirty-five-year-old male was referred for evaluation of recurrent sustained monomorphic ventricular tachycardia (VT) of 200 bpm and right bundle branch block (RBBB) morphology. Cardiac magnetic resonance imaging showed late gadolinium enhancement distributed circumferentially in the epicardial layer of the LV free wall myocardium including the rightward portion of the interventricular septum (IVS). The clinical RBBB VT was reproduced during the EP study. Ablation at an LV septum site with absence of abnormal electrograms and a suboptimum pacemap rendered the VT of clinical morphology noninducible. Three other VTs, all of left bundle branch block (LBBB) pattern, were induced by programmed electrical stimulation. The regions corresponding to abnormal electrograms were identified and ablated at the mid-to-apical RV septum and the anteroseptal portion of the right ventricular outflow tract. No abnormalities were found at the RV free wall including the inferolateral peritricuspid annulus region. Histological examination confirmed the presence of abnormal fibrous and adipose tissue with myocyte reduction in endomyocardial samples taken from both the left and right aspects of the IVS. LDAC rarely manifests with sustained monomorphic ventricular tachycardia. In this case, several VTs of both RBBB and LBBB morphology were amenable to endocardial radiofrequency catheter ablation.

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block.

PubMed

Cabeda, Estêvan Vieira; Falcão, Andréa Maria Gomes; Soares, José; Rochitte, Carlos Eduardo; Nomura, César Higa; Ávila, Luiz Francisco Rodrigues; Parga, José Rodrigues

2015-12-01

Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution's ethics committee. The patients' mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

Electrocardiographic features of patients with earthquake related posttraumatic stress disorder

PubMed Central

İlhan, Erkan; Kaplan, Abdullah; Güvenç, Tolga Sinan; Biteker, Murat; Karabulut, Evindar; Işıklı, Serhan

2013-01-01

AIM: To analyze electrocardiographic features of patients diagnosed with posttraumatic stress disorder (PTSD) after the Van-Erciş earthquake, with a shock measuring 7.2 on the Richter scale that took place in Turkey in October 2011. METHODS: Surface electrocardiograms of 12 patients with PTSD admitted to Van Erciş State Hospital (Van, Turkey) from February 2012 to May 2012 were examined. Psychiatric interviews of the sex and age matched control subjects, who had experienced the earthquake, confirmed the absence of any known diagnosable psychiatric conditions in the control group. RESULTS: A wide range of electrocardiogram (ECG) parameters, such as P-wave dispersion, QT dispersion, QT interval, Tpeak to Tend interval, intrinsicoid deflection durations and other traditional parameters were similar in both groups. There was no one with an abnormal P wave axis, short or long PR interval, long or short QT interval, negative T wave in lateral leads, abnormal T wave axis, abnormal left or right intrinsicoid deflection duration, low voltage, left bundle branch block, right bundle branch block, left posterior hemiblock, left or right axis deviation, left ventricular hypertrophy, right or left atrial enlargement and pathological q(Q) wave in either group. CONCLUSION: The study showed no direct effect of earthquake related PTSD on surface ECG in young patients. So, we propose that PTSD has no direct effect on surface ECG but may cause electrocardiographic changes indirectly by triggering atherosclerosis and/or contributing to the ongoing atherosclerotic process. PMID:23538549

Fibrillatory conduction in branching atrial tissue--Insight from volumetric and monolayer computer models.

PubMed

Wieser, L; Fischer, G; Nowak, C N; Tilg, B

2007-05-01

Increased local load in branching atrial tissue (muscle fibers and bundle insertions) influences wave propagation during atrial fibrillation (AF). This computer model study reveals two principal phenomena: if the branching is distant from the driving rotor (>19 mm), the load causes local slowing of conduction or wavebreaks. If the driving rotor is close to the branching, the increased load causes first a slow drift of the rotor towards the branching. Finally, the rotor anchors, and a stable, repeatable pattern of activation can be observed. Variation of the bundle geometry from a cylindrical, volumetric structure to a flat strip of a comparable load in a monolayer model changed the local activation sequence in the proximity of the bundle. However, the global behavior and the basic effects are similar in all models. Wavebreaks in branching tissue contribute to the chaotic nature of AF (fibrillatory conduction). The stabilization (anchoring) of driving rotors by branching tissue might contribute to maintain sustained AF.

Impaired endocytosis of the ion channel TRPM4 is associated with human progressive familial heart block type I.

PubMed

Kruse, Martin; Schulze-Bahr, Eric; Corfield, Valerie; Beckmann, Alf; Stallmeyer, Birgit; Kurtbay, Güven; Ohmert, Iris; Schulze-Bahr, Ellen; Brink, Paul; Pongs, Olaf

2009-09-01

Progressive familial heart block type I (PFHBI) is a progressive cardiac bundle branch disease in the His-Purkinje system that exhibits autosomal-dominant inheritance. In 3 branches of a large South African Afrikaner pedigree with an autosomal-dominant form of PFHBI, we identified the mutation c.19G-->A in the transient receptor potential cation channel, subfamily M, member 4 gene (TRPM4) at chromosomal locus 19q13.3. This mutation predicted the amino acid substitution p.E7K in the TRPM4 amino terminus. TRPM4 encodes a Ca2+-activated nonselective cation (CAN) channel that belongs to the transient receptor potential melastatin ion channel family. Quantitative analysis of TRPM4 mRNA content in human cardiac tissue showed the highest expression level in Purkinje fibers. Cellular expression studies showed that the c.19G-->A missense mutation attenuated deSUMOylation of the TRPM4 channel. The resulting constitutive SUMOylation of the mutant TRPM4 channel impaired endocytosis and led to elevated TRPM4 channel density at the cell surface. Our data therefore revealed a gain-of-function mechanism underlying this type of familial heart block.

Impaired endocytosis of the ion channel TRPM4 is associated with human progressive familial heart block type I

PubMed Central

Kruse, Martin; Schulze-Bahr, Eric; Corfield, Valerie; Beckmann, Alf; Stallmeyer, Birgit; Kurtbay, Güven; Ohmert, Iris; Schulze-Bahr, Ellen; Brink, Paul; Pongs, Olaf

2009-01-01

Progressive familial heart block type I (PFHBI) is a progressive cardiac bundle branch disease in the His-Purkinje system that exhibits autosomal-dominant inheritance. In 3 branches of a large South African Afrikaner pedigree with an autosomal-dominant form of PFHBI, we identified the mutation c.19G→A in the transient receptor potential cation channel, subfamily M, member 4 gene (TRPM4) at chromosomal locus 19q13.3. This mutation predicted the amino acid substitution p.E7K in the TRPM4 amino terminus. TRPM4 encodes a Ca2+-activated nonselective cation (CAN) channel that belongs to the transient receptor potential melastatin ion channel family. Quantitative analysis of TRPM4 mRNA content in human cardiac tissue showed the highest expression level in Purkinje fibers. Cellular expression studies showed that the c.19G→A missense mutation attenuated deSUMOylation of the TRPM4 channel. The resulting constitutive SUMOylation of the mutant TRPM4 channel impaired endocytosis and led to elevated TRPM4 channel density at the cell surface. Our data therefore revealed a gain-of-function mechanism underlying this type of familial heart block. PMID:19726882

New micro waveforms firstly recorded on electrocardiogram in human.

PubMed

Liu, Renguang; Chang, Qinghua; Chen, Juan

2015-10-01

In our study, not only the P-QRS-T waves but also the micro-wavelets before QRS complex (in P wave and PR segment) and after QRS complex (ST segment and upstroke of T wave) were first to be identified on surface electrocardiogram in human by the "new electrocardiogram" machine (model PHS-A10) according to conventional 12-lead electrocardiogram connection methods. By comparison to the conventional electrocardiogram in 100 cases of healthy individuals and several patients with arrhythmias, we have found that the wavelets before P wave theoretically reflected electrical activity of sinus node and the micro-wavelets before QRS complex may be related to atrioventricular conduction system (atrioventricular node, His bundle and bundle branch) potentials. Noninvasive atrioventricular node and His bundle potential tracing will contribute to differentiation of the origin of wide QRS and the location of the atrioventricular block. We also have found that the wavelets after QRS complex may be associated with phase 2 and 3 repolarization of ventricular action potential, which will further reveal ventricular repolarization changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lattice model for self-assembly with application to the formation of cytoskeletal-like structures

NASA Astrophysics Data System (ADS)

Stewman, Shannon F.; Dinner, Aaron R.

2007-07-01

We introduce a stochastic approach for self-assembly in systems far from equilibrium. The building blocks are represented by a lattice of discrete variables (Potts-like spins), and physically meaningful mechanisms are obtained by restricting transitions through spatially local rules based on experimental data. We use the method to study nucleation of filopodia-like bundles in a system consisting of purified actin, fascin, actin-related protein 2/3 , and beads coated with Wiskott-Aldrich syndrome protein. Consistent with previous speculation based on static experimental images, we find that bundles derive from Λ -precursor-like patterns of spins on the lattice. The ratcheting of the actin network relative to the surface that represents beads plays an important role in determining the number and orientation of bundles due to the fact that branching is the primary means for generating barbed ends pointed in directions that allow rapid filament growth. By enabling the de novo formation of coexisting morphologies without the computational cost of explicit representation of proteins, the approach introduced complements earlier models of cytoskeletal behavior in vitro and in vivo.

The Role of Echocardiography in the Optimization of Cardiac Resynchronization Therapy: Current Evidence and Future Perspectives.

PubMed

Spartalis, Michael; Tzatzaki, Eleni; Spartalis, Eleftherios; Damaskos, Christos; Athanasiou, Antonios; Livanis, Efthimios; Voudris, Vassilis

2017-01-01

Cardiac resynchronization therapy (CRT) has become a mainstay in the management of heart failure. Up to one-third of patients who received resynchronization devices do not experience the full benefits of CRT. The clinical factors influencing the likelihood to respond to the therapy are wide QRS complex, left bundle branch block, female gender, non-ischaemic cardiomyopathy (highest responders), male gender, ischaemic cardiomyopathy (moderate responders) and narrow QRS complex, non-left bundle branch block (lowest, non-responders). This review provides a conceptual description of the role of echocardiography in the optimization of CRT. A literature survey was performed using PubMed database search to gather information regarding CRT and echocardiography. A total of 70 studies met selection criteria for inclusion in the review. Echocardiography helps in the initial selection of the patients with dyssynchrony, which will benefit the most from optimal biventricular pacing and provides a guide to left ventricular (LV) lead placement during implantation. Different echocardiographic parameters have shown promise and can offer the possibility of patient selection, response prediction, lead placement optimization strategies and optimization of device configurations. LV ejection fraction along with specific electrocardiographic criteria remains the cornerstone of CRT patient selection. Echocardiography is a non-invasive, cost-effective, highly reproducible method with certain limitations and accuracy that is affected by measurement errors. Echocardiography can assist with the identification of the appropriate electromechanical substrate of CRT response and LV lead placement. The targeted approach can improve the haemodynamic response, as also the patient-specific parameters estimation.

The Role of Echocardiography in the Optimization of Cardiac Resynchronization Therapy: Current Evidence and Future Perspectives

PubMed Central

Spartalis, Michael; Tzatzaki, Eleni; Spartalis, Eleftherios; Damaskos, Christos; Athanasiou, Antonios; Livanis, Efthimios; Voudris, Vassilis

2017-01-01

Background: Cardiac resynchronization therapy (CRT) has become a mainstay in the management of heart failure. Up to one-third of patients who received resynchronization devices do not experience the full benefits of CRT. The clinical factors influencing the likelihood to respond to the therapy are wide QRS complex, left bundle branch block, female gender, non-ischaemic cardiomyopathy (highest responders), male gender, ischaemic cardiomyopathy (moderate responders) and narrow QRS complex, non-left bundle branch block (lowest, non-responders). Objective: This review provides a conceptual description of the role of echocardiography in the optimization of CRT. Method: A literature survey was performed using PubMed database search to gather information regarding CRT and echocardiography. Results: A total of 70 studies met selection criteria for inclusion in the review. Echocardiography helps in the initial selection of the patients with dyssynchrony, which will benefit the most from optimal biventricular pacing and provides a guide to left ventricular (LV) lead placement during implantation. Different echocardiographic parameters have shown promise and can offer the possibility of patient selection, response prediction, lead placement optimization strategies and optimization of device configurations. Conclusion: LV ejection fraction along with specific electrocardiographic criteria remains the cornerstone of CRT patient selection. Echocardiography is a non-invasive, cost-effective, highly reproducible method with certain limitations and accuracy that is affected by measurement errors. Echocardiography can assist with the identification of the appropriate electromechanical substrate of CRT response and LV lead placement. The targeted approach can improve the haemodynamic response, as also the patient-specific parameters estimation. PMID:29387277

Bundle branch block after ablation for Wolff-Parkinson-White syndrome.

PubMed

Fuenmayor A, Abdel J; Rodríguez S, Yenny A

2013-09-20

Bundle branch block (BBB) is a difficult diagnosis in the Wolff-Parkinson-White syndrome (WPW). We investigated the clinical implications of BBB that appears after performing an accessory pathway (AP) ablation. We studied 199 patients with WPW who were submitted to AP ablation. Thirty (15%) exhibited BBB after the ablation. Twenty-two patients had right BBB and 8 had left BBB. Thirteen patients had right-sided AP and 17 had left-sided AP. They were compared with 82 similar patients without BBB after the AP ablation. Among the patients with BBB, 86.66% showed delays in the middle part of the QRS in the ECG recorded before ablation vs. 18.29% of the patients without BBB (p<0.05) (sensitivity 86%, specificity 81%, positive predictive value 67% and negative predictive value 93%). Forty-four percent of the patients with BBB had BBB morphology during orthodromic tachycardia vs. 10% of the patients without BBB (p<0.05) (sensitivity 44%, specificity 89%, positive predictive value 57% and negative predictive value 82%). No relationship was found between AP location and the site of the BBB. Ejection fraction was normal before (0.61 ± 0.03) and upon completion of follow-up (0.61 ± 0.07). BBB disappeared in 95.3% of the patients. Delays in the middle portion of the QRS may predict BBB after AP ablation. BBB after performing AP ablation is frequent, transient, benign, and not related to either the ablation lesion location or progression to structural heart disease. BBB after AP ablation may be related to cardiac memory. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum.

PubMed

Martini, Bortolo; Trevisi, Nicola; Martini, Nicolò; Zhang, Li

2015-01-01

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum

PubMed Central

Martini, Bortolo; Trevisi, Nicola; Martini, Nicolò; Zhang, Li

2015-01-01

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches. PMID:26509086

DDD pacemaker for severe heart failure-alternate to CRT.

PubMed

Krishnamani, N C

Patients with severe systolic Heart Failure continue to have poor quality of life and increased mortality in spite of optimal medical management. Cardiac Resynchronization Therapy [CRT] is promising modality in patients with systolic heart failure and electrocardiographic [ECG] evidence of left bundle branch block [LBBB]. Cost issues continue to elude many deserving cases of this therapy in our society. Relatively cost effective Dual chamber pacing [DDD] with right atrial and isolated left ventricular pacing [RA-LV] can be a good alternative. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Use of an Active-Fixation Coronary Sinus Lead to Implant a Biventricular Pacemaker via the Femoral Vein

PubMed Central

Shandling, Adrian; Donohue, Daniel; Tobias, Serge; Wu, Iris; Brar, Ramandeep

2010-01-01

Cardiac resynchronization therapy, which involves the placement of a pacing lead in the right atrium and in each ventricle, is effective in treating heart failure that is caused by left bundle branch block and cardiomyopathy. The left ventricular lead is usually placed into a lateral branch of the coronary sinus via the subclavian route. When the subclavian route is unavailable, insertion of a standard, passive-fixation coronary sinus lead via the femoral approach is feasible; however, the likelihood of subsequent dislodgment is high. Herein, we describe the placement of a novel, self-retaining, active-fixation coronary sinus lead—the Attain StarFix® Model 4195 OTW Lead—in an elderly heart-failure patient, via the femoral approach. We believe that this is the 1st report of this procedure. PMID:20200636

Prognosis assessment of persistent left bundle branch block after TAVI by an electrophysiological and remote monitoring risk-adapted algorithm: rationale and design of the multicentre LBBB-TAVI Study.

PubMed

Massoullié, Grégoire; Bordachar, Pierre; Irles, Didier; Caussin, Christophe; Da Costa, Antoine; Defaye, Pascal; Jean, Frédéric; Mechulan, Alexis; Mondoly, Pierre; Souteyrand, Géraud; Pereira, Bruno; Ploux, Sylvain; Eschalier, Romain

2016-10-26

Percutaneous aortic valve replacement (transcatheter aortic valve implantation (TAVI)) notably increases the likelihood of the appearance of a complete left bundle branch block (LBBB) by direct lesion of the LBB of His. This block can lead to high-grade atrioventricular conduction disturbances responsible for a poorer prognosis. The management of this complication remains controversial. The screening of LBBB after TAVI persisting for more than 24 hours will be conducted by surface ECG. Stratification will be performed by post-TAVI intracardiac electrophysiological study. Patients at high risk of conduction disturbances (≥70 ms His-ventricle interval (HV) or presence of infra-Hisian block) will be implanted with a pacemaker enabling the recording of disturbance episodes. Those at lower risk (HV <70 ms) will be implanted with a loop recorder device with remote monitoring of cardiovascular implantable electronic devices (CIEDs). Clinical, ECG and implanted device follow-up will also be performed at 3, 6 and 12 months. The primary objective is to assess the efficacy and safety of a decisional algorithm based on electrophysiological study and remote monitoring of CIEDs in the prediction of high-grade conduction disturbances in patients with LBBB after TAVI. The primary end point is to compare the incidence (rate and time to onset) of high-grade conduction disturbances in patients with LBBB after TAVI between the two groups at 12 months. Given the proportion of high-grade conduction disturbances (20-40%), a sample of 200 subjects will allow a margin of error of 6-7%. The LBBB-TAVI Study has been in an active recruiting phase since September 2015 (21 patients already included). Local ethics committee authorisation was obtained in May 2015. We will publish findings from this study in a peer-reviewed scientific journal and present results at national and international conferences. NCT02482844; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

An electrocardiographic scoring system for distinguishing right ventricular outflow tract arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy from idiopathic ventricular tachycardia.

PubMed

Hoffmayer, Kurt S; Bhave, Prashant D; Marcus, Gregory M; James, Cynthia A; Tichnell, Crystal; Chopra, Nagesh; Moxey, Laura; Krahn, Andrew D; Dixit, Sanjay; Stevenson, William; Calkins, Hugh; Badhwar, Nitish; Gerstenfeld, Edward P; Scheinman, Melvin M

2013-04-01

Ventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and idiopathic ventricular tachycardia (VT) can share a left bundle branch block/inferior axis morphology. We previously reported electrocardiogram characteristics during outflow tract ventricular arrhythmias that helped distinguish VT related to ARVD/C from idiopathic VT. To prospectively validate these criteria. We created a risk score by using a derivation cohort. Two experienced electrophysiologists blinded to the diagnosis prospectively scored patients with VT/premature ventricular contractions (PVCs) with left bundle branch block/inferior axis pattern in a validation cohort of 37 ARVD/C tracings and 49 idiopathic VT tracings. All patients with ARVD/C had their diagnosis confirmed based on the revised task force criteria. Patients with idiopathic VT were selected based on structurally normal hearts with documented right ventricular outflow tract VT successfully treated with ablation. The scoring system provides 3 points for sinus rhythm anterior T-wave inversions in leads V1-V3 and during ventricular arrhythmia: 2 points for QRS duration in lead I≥120 ms, 2 points for QRS notching, and 1 point for precordial transition at lead V5 or later. A score of 5 or greater was able to correctly distinguish ARVD/C from idiopathic VT 93% of the time, with a sensitivity of 84%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 91%. We describe a simple scoring algorithm that uses 12-lead electrocardiogram characteristics to effectively distinguish right ventricular outflow tract arrhythmias originating from patients with ARVD/C versus patients with idiopathic VT. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Ventricular dilation and electrical dyssynchrony synergistically increase regional mechanical nonuniformity but not mechanical dyssynchrony: a computational model.

PubMed

Kerckhoffs, Roy C P; Omens, Jeffrey H; McCulloch, Andrew D; Mulligan, Lawrence J

2010-07-01

Heart failure (HF) in combination with mechanical dyssynchrony is associated with a high mortality rate. To quantify contractile dysfunction in patients with HF, investigators have proposed several indices of mechanical dyssynchrony, including percentile range of time to peak shortening (WTpeak), circumferential uniformity ratio estimate (CURE), and internal stretch fraction (ISF). The goal of this study was to compare the sensitivity of these indices to 4 major abnormalities responsible for cardiac dysfunction in dyssynchronous HF: dilation, negative inotropy, negative lusitropy, and dyssynchronous activation. All combinations of these 4 major abnormalities were included in 3D computational models of ventricular electromechanics. Compared with a nonfailing heart model, ventricles were dilated, inotropy was reduced, twitch duration was prolonged, and activation sequence was changed from normal to left bundle branch block. In the nonfailing heart, CURE, ISF, and WTpeak were 0.97+/-0.004, 0.010+/-0.002, and 78+/-1 milliseconds, respectively. With dilation alone, CURE decreased 2.0+/-0.07%, ISF increased 58+/-47%, and WTpeak increased 31+/-3%. With dyssynchronous activation alone, CURE decreased 15+/-0.6%, ISF increased 14-fold (+/-3), and WTpeak increased 121+/-4%. With the combination of dilation and dyssynchronous activation, CURE decreased 23+/-0.8%, ISF increased 20-fold (+/-5), and WTpeak increased 147+/-5%. Dilation and left bundle branch block combined synergistically decreased regional cardiac function. CURE and ISF were sensitive to this combination, but WTpeak was not. CURE and ISF also reflected the relative nonuniform distribution of regional work better than WTpeak. These findings might explain why CURE and ISF are better predictors of reverse remodeling in cardiac resynchronization therapy.

Mechanisms of right ventricular electromechanical dyssynchrony and mechanical inefficiency in children after repair of tetralogy of fallot.

PubMed

Hui, Wei; Slorach, Cameron; Dragulescu, Andreea; Mertens, Luc; Bijnens, Bart; Friedberg, Mark K

2014-07-01

Right bundle branch block and right ventricular (RV) dysfunction are common after tetralogy of Fallot repair (rTOF). We hypothesized that right bundle branch block is associated with specific RV mechanical dyssynchrony and inefficient contraction. We studied rTOF children and age-matched controls. QRS duration and morphology were assessed. RV mechanical dyssynchrony, indicated by early septal activation (right-sided septal flash), RV lateral wall prestretch/late contraction, postsystolic shortening, and intraventricular delay were analyzed using 2-dimensional strain echocardiography. Peak oxygen consumption reflected exercise capacity. Pulmonary regurgitation and RV volumes were assessed by MRI. Forty-six rTOF patients and 46 controls were studied. Ninety-three percent of rTOF patients demonstrated a right-sided septal flash with simultaneous RV basal lateral wall prestretch/late activation. The RV basal segment was the most delayed in onset (115 [0-194] versus 35 [0-96] ms) and termination (462 [369-706] versus 412 [325-529] ms) of longitudinal shortening, with postsystolic shortening. QRS duration correlated with RV basal time to onset and peak shortening (P<0.05). Intra-RV delay was higher in rTOF (P<0.05) in association with RV dilatation (r=0.33; P=0.04). In rTOF, RV mechanics were inefficient, with prestretch and postsystolic shortening comprising 15±11% and 16±9% of total shortening, respectively. A composite parameter of electric and mechanical dyssynchrony correlated with RV end-diastolic volume (r=0.39; P=0.03). Typical electromechanical dyssynchrony associated with mechanical inefficiency, regional dysfunction, and RV dilatation is common in rTOF children, possibly contributing to progressive RV dysfunction. The potential of cardiac resynchronization in appropriate patients requires further study. © 2014 American Heart Association, Inc.

Beyond the Length and Look of Repolarization: Defining the Non-QTc Electrocardiographic Profiles of Patients with Congenital Long QT Syndrome.

PubMed

Lane, Conor M; Bos, J Martijn; Rohatgi, Ram K; Ackerman, Michael J

2018-04-30

Little is known about the spectrum and prevalence of ECG features beyond the length and morphology of repolarization in patients with congenital long QT syndrome (LQTS). To characterize the full ECG phenotype of LQTS patients and evaluate differences by age and LQTS genotype. Retrospective review of 943 patients with LQTS (57% female, median age 25 years; IQR 9 - 34 years) was performed. Comprehensive analysis of their initial evaluation ECG was performed using definitions outlined in Heart Rhythm Society guidelines. Bradycardia was common (n=320; 34%), regardless of beta-blocker use. Left axis deviation (n=33, 3.5%) and bundle branch block (n=5, 0.5%) were uncommon. T-wave inversion (TWI) involving leads V1 and V3 was more common in LQT2 compared to LQT1 or LQT3 [OR for V1: 2.67 (95% CI 1.8 - 3.9) and OR for V3: 1.76 (95% CI 1.2 - 2.6)], while TWI in lead III and aVF was most common in LQT3 [OR for III: 2.38 (95% CI 1.4 - 4.2) and OR for aVF: 3.14 (95% CI 1.6 - 6.4)]. Notched T-waves were most apparent at younger ages (48% in patients between ages 4-10 compared to 12% in over 40s, p <0.0001). Beyond the QT interval and bradycardia, ECG abnormalities are uncommon in LQTS patients and patients almost never have concomitant bundle branch block. Notably, 19% of LQTS patients overall and 27% of LQT2 patients exhibit anterior TWI that would satisfy a diagnostic criterion for arrhythmogenic right ventricular cardiomyopathy creating the potential for diagnostic miscues. Copyright © 2018. Published by Elsevier Inc.

Do we overestimate left ventricular ejection fraction by two-dimensional echocardiography in patients with left bundle branch block?

PubMed

Cabuk, Ali K; Cabuk, Gizem; Sayin, Ahmet; Karamanlioglu, Murat; Kilicaslan, Barış; Ekmekci, Cenk; Solmaz, Hatice; Aslanturk, Omer F; Ozdogan, Oner

2018-02-01

Left bundle branch block (LBBB) causes a dyssynchronized contraction of left ventricle. This is a kind of regional wall-motion abnormality and measuring left ventricular ejection fraction (LVEF) by two-dimensional (2D) echocardiography could be less reliable in this particular condition. Our aim was to evaluate the role of dyssynchrony index (SDI), measured by three-dimensional (3D) echocardiography, in assessment of LVEF and left ventricular volumes accurately in patients with LBBB. In this case-control study, we included 52 of 64 enrolled participants (twelve participants with poor image quality were excluded) with LBBB and normal LVEF or nonischemic cardiomyopathy. Left ventricular ejection fraction (LVEF) and left ventricular volumes were assessed by 2D (modified Simpson's rule) and 3D (four beats full volume analysis) echocardiography and the impact of SDI on results were evaluated. In patients with SDI ≥6%, LVEF measurements were significantly different (46.00% [29.50-52.50] vs 37.60% [24.70-45.15], P < .001) between 2D and 3D echocardiography, respectively. In patients with SDI < 6%, there were no significant differences between two modalities in terms of LVEF measurements (54.50% [49.00-59.00] vs 54.25% [40.00-58.25], P = .193). LV diastolic volumes were not significantly different while systolic volumes were underestimated by 2D echocardiography, and this finding was more pronounced when SDI ≥ 6%. In patients with LBBB and high SDI (≥6%), LVEF values were overestimated and systolic volumes were underestimated by 2D echocardiography compared to 3D echocardiography. © 2017 Wiley Periodicals, Inc.

Septal and Anterior Reverse Mismatch of Myocardial Perfusion and Metabolism in Patients With Coronary Artery Disease and Left Bundle Branch Block

PubMed Central

Wang, Jian-Guang; Fang, Wei; Yang, Min-Fu; Tian, Yue-Qin; Zhang, Xiao-Li; Shen, Rui; Sun, Xiao-Xin; Guo, Feng; Wang, Dao-Yu; He, Zuo-Xiang

2015-01-01

Abstract The effects of left bundle branch block (LBBB) on left ventricular myocardial metabolism have not been well investigated. This study evaluated these effects in patients with coronary artery disease (CAD). Sixty-five CAD patients with complete LBBB (mean age, 61.8 ± 9.7 years) and 65 without LBBB (mean age, 59.9 ± 8.4 years) underwent single photon emission computed tomography, positron emission tomography, and contrast coronary angiography. The relationship between myocardial perfusion and metabolism and reverse mismatch score, and that between QRS length and reverse mismatch score and wall motion score were evaluated. The incidence of left ventricular septum and anterior wall reverse mismatching between the two groups was significantly different (P < 0.001 and P = 0.002, respectively). The incidences of normal myocardial perfusion and metabolism in the left ventricular lateral and inferior walls were also significantly different between the two groups (P < 0.001 and P < 0.001, respectively). The incidence of septal reverse mismatching in patients with mild to moderate perfusion was significantly higher among those with LBBB than among those without LBBB (P < 0.001). In CAD patients with LBBB, septal reverse mismatching was significantly more common among those with mild to moderate perfusion than among those with severe perfusion defects (P = 0.002). The correlation between the septal reverse mismatch score and QRS length was significant (P = 0.026). In patients with CAD and LBBB, septal and anterior reverse mismatching of myocardial perfusion and metabolism was frequently present; the septal reverse mismatch score negatively correlated with the QRS interval. PMID:25997045

Comparative Effectiveness of Cardiac Resynchronization Therapy Defibrillators Versus Standard Implantable Defibrillators in Medicare Patients.

PubMed

Zusterzeel, Robbert; Caños, Daniel A; Sanders, William E; Silverman, Henry; MaCurdy, Thomas E; Worrall, Christopher M; Kelman, Jeffrey; Marinac-Dabic, Danica; Strauss, David G

2015-07-01

Previous analyses have shown that there is lower mortality with cardiac resynchronization therapy defibrillators (CRT-D) in patients with left bundle branch block (LBBB) but demonstrated mixed results in patients without LBBB. We evaluated the comparative effectiveness of CRT-D versus standard implantable defibrillators (ICDs) separately in patients with LBBB and right bundle branch block (RBBB) using Medicare claims data. Medicare records from CRT-D and ICD recipients from 2002 to 2009 that were followed up for up to 48 months were analyzed. We used propensity scores to match patients with ICD to those with CRT-D. In LBBB, 1:1 matching with replacement resulted in 54,218 patients with CRT-D and 20,763 with ICD, and in RBBB, 1:1 matching resulted in 7,298 patients with CRT-D and 7,298 with ICD. In LBBB, CRT-D had a 12% lower risk of heart failure hospitalization or death (hazard ratio [HR] 0.88, 95% confidence interval 0.86 to 0.90) and 5% lower death risk (HR 0.95, 0.92 to 0.97) compared with ICD. In RBBB, CRT-D had a 15% higher risk of heart failure hospitalization or death (HR 1.15, 1.10 to 1.20) and 13% higher death risk (HR 1.13, 1.07 to 1.18). Sensitivity analysis revealed that accounting for covariates not captured in the Medicare database may lead to increased benefit with CRT-D in LBBB and no difference in RBBB. In conclusion, in a large Medicare population, CRT-D was associated with lower mortality in LBBB but higher mortality in RBBB. The absence of certain covariates, in particular those that determine treatment selection, may affect the results of comparative effectiveness studies using claims data. Published by Elsevier Inc.

Value of right ventricular mapping in patients with postinfarction ventricular tachycardia.

PubMed

Yokokawa, Miki; Good, Eric; Crawford, Thomas; Chugh, Aman; Pelosi, Frank; Latchamsetty, Rakesh; Oral, Hakan; Morady, Fred; Bogun, Frank

2012-06-01

Postinfarction ventricular tachycardia (VT) typically involves the left ventricular endocardium. Right ventricular involvement in the arrhythmogenic substrate of postinfarction VT is considered unusual. To assess the role of right ventricular mapping and ablation in patients with prior septal myocardial infarction. From among 37 consecutive patients with recurrent postinfarction VT, 18 patients with evidence of left ventricular septal involvement of myocardial infarction were identified; these patients were the subjects of this report. In these 18 patients, 166 VTs (cycle length 372 ± 117 ms) were induced. Right ventricular voltage mapping was performed in all 18 patients with left ventricular septal myocardial infarction. Right ventricular voltage mapping showed areas of low voltage in 11 patients; pace mapping from these areas revealed matching pace maps for 17 VTs, and radiofrequency ablation from the right ventricular endocardium but not the left ventricular endocardium eliminated 14 of 17 VTs. VTs with critical components in the right ventricle had a left bundle branch block morphology that had similar characteristics as left bundle branch block VTs with critical areas involving the left ventricular septum. Patients with right ventricular VT breakthrough sites had a lower ejection fraction than did patients without VT breaking out on the right ventricular septum (18% ± 5% vs 33% ± 15%; P = .01). Right ventricular mapping and ablation may be necessary in order to eliminate all inducible VTs in patients with postinfarction VT. More than half the patients with septal myocardial infarction have right ventricular septal areas that are critical for postinfarction VT and that cannot be eliminated by left ventricular ablation alone. Copyright © 2012 Heart Rhythm Society. All rights reserved.

Electrocardiographic findings in Emergency Department patients with pulmonary embolism.

PubMed

Richman, Peter B; Loutfi, Hassan; Lester, Steven J; Cambell, Patricia; Matthews, Jessica; Friese, Jeremy; Wood, Joseph; Kasper, David; Chen, Frederick; Mandell, Mark

2004-08-01

To assess the pre-study, null hypothesis that there is no difference in the electrocardiogram (EKG) findings for Emergency Department (ED) patients who rule in vs. rule out for suspected pulmonary embolism, a retrospective review of a cohort of patients with pulmonary embolism and their controls was conducted in an academic, suburban ED. Patients who were evaluated in the ED during a one-year study period for symptoms suggestive of pulmonary embolism were eligible for inclusion. All patients with pulmonary embolism and sex- and age-matched controls comprised the final study groups. Two board-certified cardiologists reviewed each patient's EKG. There were 350 eligible patients identified; 49 patients with pulmonary embolism and 49 controls were entered into the study. The most common rhythm observed in both groups was normal sinus rhythm (67.3% cases vs. 68.6 % controls; p = 1.0). Abnormalities believed to be associated with pulmonary embolism occurred with similar frequency in both case and control groups (sinus tachycardia [18.8 % vs. 11.8%, respectively; p = 0.40]), incomplete right bundle branch block (4.2% vs. 0.0%, respectively; p = 0.24), complete right bundle branch block (4.2% vs. 6.0, respectively; p = 1.0), S1Q3T3 pattern (2.1 vs. 0.0, respectively; p = 0.49), S1Q3 pattern (0.0 vs. 0.0), and extreme right axis (0.0 vs. 0.0). New EKG changes were identified more frequently for patients with pulmonary embolism (33.3% vs. 12.5% controls; p = 0.03), but specific findings were rarely different between cases and controls. In our cohort of ED patients, we did not identify EKG features that are likely to help distinguish patients with pulmonary embolism from those who rule out for the disease.

National economic impact of tirofiban for unstable angina and myocardial infarction without ST elevation; example from the United Kingdom.

PubMed

Bakhai, Ameet; Flather, Marcus D; Collinson, Julian R; Stevens, Warren; Normand, Charles; Alemao, Evo; Itzler, Robbin; Ben-Joseph, Rami

2003-10-01

Acute coronary syndromes without ST elevation are a major health and economic burden. Treatments such as glycoprotein IIb/IIIa antagonists like tirofiban reduce the risk of complications but the cost impact of these agents including cost offsets of avoiding complications are needed particularly in Europe. We used treatment patterns from the Prospective Registry of Acute Ischemic Syndromes in the UK, risk reductions derived from the PRISM-PLUS trial and cost estimates from the CHKS database to estimate the impact of tirofiban on PRAIS-UK patients with and without complications and subgroups at higher risk of complications. These subgroups (and proportions) were patients: (1) aged 60 or over with abnormal electrocardiograms (58%), (2) with ST depression or bundle branch block on admission (30%) and (3) with ST depression, bundle branch block or MI on admission (37%). Total cost of care in the UK at 6 months for the estimated 87339 acute coronary syndromes admissions annually was pound 213 million, which would increase by pound 33 million (15.7%) if tirofiban were given to all patients, avoiding 2422 complications at a mean cost per event avoided of pound 13388. Among the subgroups, the mean cost per event avoided ranges from pound 10856 for subgroup 1 to pound 5953 for subgroup 3. Treating the latter subgroup, would avoid 1977 events at a cost of pound 12 million (5.5%). The use of tirofiban in the UK to treat acute coronary syndromes patients without ST elevation provides an important therapeutic advantage at modest proportional increase in cost, particularly if targeted to higher risk subgroups as recommended in the European guidelines.

Prehospital Acute ST-Elevation Myocardial Infarction Identification in San Diego: A Retrospective Analysis of the Effect of a New Software Algorithm.

PubMed

Coffey, Christanne; Serra, John; Goebel, Mat; Espinoza, Sarah; Castillo, Edward; Dunford, James

2018-05-03

A significant increase in false positive ST-elevation myocardial infarction (STEMI) electrocardiogram interpretations was noted after replacement of all of the City of San Diego's 110 monitor-defibrillator units with a new brand. These concerns were brought to the manufacturer and a revised interpretive algorithm was implemented. This study evaluated the effects of a revised interpretation algorithm to identify STEMI when used by San Diego paramedics. Data were reviewed 6 months before and 6 months after the introduction of a revised interpretation algorithm. True-positive and false-positive interpretations were identified. Factors contributing to an incorrect interpretation were assessed and patient demographics were collected. A total of 372 (234 preimplementation, 138 postimplementation) cases met inclusion criteria. There was a significant reduction in false positive STEMI (150 preimplementation, 40 postimplementation; p < 0.001) after implementation. The most common factors resulting in false positive before implementation were right bundle branch block, left bundle branch block, and atrial fibrillation. The new algorithm corrected for these misinterpretations with most postimplementation false positives attributed to benign early repolarization and poor data quality. Subsequent follow-up at 10 months showed maintenance of the observed reduction in false positives. This study shows that introducing a revised 12-lead interpretive algorithm resulted in a significant reduction in the number of false positive STEMI electrocardiogram interpretations in a large urban emergency medical services system. Rigorous testing and standardization of new interpretative software is recommended before introduction into a clinical setting to prevent issues resulting from inappropriate cardiac catheterization laboratory activations. Copyright © 2018 Elsevier Inc. All rights reserved.

Different regions of latest electrical activation during left bundle-branch block and right ventricular pacing in cardiac resynchronization therapy patients determined by coronary venous electro-anatomic mapping.

PubMed

Mafi Rad, Masih; Blaauw, Yuri; Dinh, Trang; Pison, Laurent; Crijns, Harry J; Prinzen, Frits W; Vernooy, Kevin

2014-11-01

Current targeted left ventricular (LV) lead placement strategy is directed at the latest activated region during intrinsic activation. However, cardiac resynchronization therapy (CRT) is most commonly applied by simultaneous LV and right ventricular (RV) pacing without contribution from intrinsic conduction. Therefore, targeting the LV lead to the latest activated region during RV pacing might be more appropriate. We investigated the difference in LV electrical activation sequence between left bundle-branch block (LBBB) and RV apex (RVA) pacing using coronary venous electro-anatomic mapping (EAM). Twenty consecutive CRT candidates with LBBB underwent intra-procedural coronary venous EAM during intrinsic activation and RVA pacing using EnSite NavX. Left ventricular lead placement was aimed at the latest activated region during LBBB according to current recommendations. In all patients, LBBB was associated with a circumferential LV activation pattern, whereas RVA pacing resulted in activation from the apex of the heart to the base. In 10 of 20 patients, RVA pacing shifted the latest activated region relative to LBBB. In 18 of 20 patients, the LV lead was successfully positioned in the latest activated region during LBBB. For the whole study population, LV lead electrical delay, expressed as percentage of QRS duration, was significantly shorter during RVA pacing than during LBBB (72 ± 13 vs. 82 ± 5%, P = 0.035). Right ventricular apex pacing alters LV electrical activation pattern in CRT patients with LBBB, and shifts the latest activated region in a significant proportion of these patients. These findings warrant reconsideration of the current practice of LV lead targeting for CRT. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

The Prevalence of Chagas Heart Disease in a Central Bolivian Community Endemic for Trypanosoma Cruzi

PubMed Central

Yager, Jessica E.; Lozano Beltran, Daniel F.; Torrico, Faustino; Gilman, Robert H.; Bern, Caryn

2015-01-01

Background Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population. Objectives and Methods Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or ECG consistent with cardiac abnormalities were also scheduled for echocardiography. Results and conclusions Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% versus 0 for complete right bundle branch block and 10.4% versus 1.9% for any bundle branch block; p=0.008 and p<0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure. Though almost one third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease. PMID:26407509

Exercise induced left bundle branch block in isotopic exercise test. Findings and prognostic value.

PubMed

Gomez, M V; Lorente Castro, B C; Jané, P; García-Zoghby, L; Martínez-Lorca, A; Pérez, J A

2018-04-18

Exercise-induced left bundle branch block (EI-LBBB) is a rare circumstance of unknown significance. The purpose of this paper is to describe the scintigraphic features and the prognostic value of this finding. We reviewed the features of 1,885 patients who had visited our department to undergo GATED-SPECT ergometry to diagnose ischaemic heart disease. Seven patients showed EI-LBBB throughout the exercise testing. Coronary angiography was performed in 4 of them. Patients were followed-up over an average period of time of 30±8 months. The onset of major cardiovascular events was recorded during the follow-up period. The prevalence of EI-LBBB was 0.37%. Six out of 7 patients were women. Myocardial function and perfusion were normal in 3 patients. Three patients had fixed perfusion defects and one patient had a reversible defect. Two out of the 4 patients showing perfusion defects presented a moderate-severe decrease of the left ventricular ejection fraction. None of the 4 patients with perfusion defects were found to have coronary disease on coronary angiography. The prevalence of EI-LBBB among the patients that came to undergo GATED-SPECT ergometry was very low. The finding was more frequent in women. In our series, 2 patients presented non-ischaemic structural heart disease, but no patient was diagnosed with coronary artery disease. In our patients the presence of EI-LBBB did not relate to a greater risk of experiencing a major cardiovascular event. Copyright © 2018 Sociedad Española de Medicina Nuclear e Imagen Molecular. Publicado por Elsevier España, S.L.U. All rights reserved.

Early Changes in QRS Frequency Following Cardiac Resynchronization Predict Hemodynamic Response in Left Bundle Branch Block Patients.

PubMed

Niebauer, Mark J; Rickard, John; Tchou, Patrick J; Varma, Niraj

2016-05-01

QRS characteristics are the cornerstone of patient selection in cardiac resynchronization therapy (CRT) and the presence of left bundle branch block (LBBB) and baseline QRS ≥150 milliseconds portends a good outcome. We previously showed that baseline QRS frequency analysis adds predictive value to LBBB alone and have hypothesized that a change in frequency characteristics following CRT may produce additional predictive value. We examined the QRS frequency characteristics of 182 LBBB patients before and soon after CRT. Patients were assigned to responder and nonresponder groups. Responders were defined by a decrease in left ventricular end-systolic volume (LVESV) ≥15% following CRT. We analyzed the QRS in ECG leads I, AVF, and V3 before and soon after CRT using the discrete Fourier transform algorithm. The percentage of total QRS power within discrete frequency intervals before and after CRT was calculated. The reduction in lead V3 power <10 Hz was the best indicator of response. Baseline QRS width was similar between the responders and nonresponders (162.2 ± 17.2 milliseconds vs. 158 ± 22.1 milliseconds, respectively; P = 0.180). Responders exhibited a greater reduction in QRS power <10 Hz (-17.0 ± 11.9% vs. -6.6 ± 12.5%; P < 0.001) and a significant AUC (0.743; P < 0.001). A ≥8% decline in QRS power <10 Hz produced the best predictive values (PPV = 84%, NPV = 59%). Importantly, when patients with baseline QRS <150 milliseconds were compared, the AUC improved (0.892, P < 0.001). Successful CRT produces a significant reduction in QRS power below 10 Hz, particularly when baseline QRS <150 milliseconds. These results indicate that QRS frequency changes after CRT provide additional predictive value to QRS alone. © 2016 Wiley Periodicals, Inc.

The normal variants in the left bundle branch system.

PubMed

Elizari, M V

This article reviewed the main anatomic and physiopathological aspects of the left bundle branch from its origin in the His bundle and its intraventricular distribution on the left endocardial surface. The results are based on the relevant literature and on personal observations executed on 206 hearts distributed as follows: 67 dogs, 60 humans, 45 sheep, 22 pigs, 10 cows, 2 monkeys, 1 guanaco, and 1 sea lion. The main anatomical features of the His-Purkinje conducting system may be summarized as follows: The bundle of His is composed by two segments: the penetrating and branching portions. LBB originates in the branching portion located underneath the membranous septum. There is no true bifurcation of the bundle of His in a human heart. Short after its origin the LBB gives rise to its two main fascicles, anterior and posterior, both heading the anterior and posterior papillary muscles, respectively. The anterior division is thinner and longer than the posterior one. The RBB and the most anterior fibers of the LBB arise at the end of the branching portion. In some cases a well-defined left septal fascicle can be identified, usually arising from the posterior division. Each division gives off small fibers and false tendons crossing the left ventricular cavity connecting the papillary between them or the papillary muscles with the septal surface. From each division of the LBB, their corresponding Purkinje networks emerge covering the subendocardium of the septum and the free wall of the left ventricles. There are critical relationships of the proximal segments of the His-Purkinje system with the surrounding cardiac structures whose pathologic processes may damage the conducting tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

3D Heart: a new visual training method for electrocardiographic analysis.

PubMed

Olson, Charles W; Lange, David; Chan, Jack-Kang; Olson, Kim E; Albano, Alfred; Wagner, Galen S; Selvester, Ronald H S

2007-01-01

This new training method is based on developing a sound understanding of the sequence in which electrical excitation spreads through both the normal and the infarcted myocardium. The student is made aware of the cardiac electrical performance through a series of 3-dimensional pictures during the excitation process. The electrocardiogram 3D Heart 3-dimensional program contains a variety of different activation simulations. Currently, this program enables the user to view the activation simulation for all of the following pathology examples: normal activation; large, medium, and small anterior myocardial infarction (MI); large, medium, and small posterolateral MI; large, medium, and small inferior MI. Simulations relating to other cardiac abnormalities, such as bundle branch block and left ventricular hypertrophy fasicular block, are being developed as part of a National Institute of Health (NIH) Phase 1 Small Business Innovation Research (SBIR) program.

Non-selective His bundle pacing with a biphasic waveform: enhancing septal resynchronization.

PubMed

Ortega, Daniel F; Barja, Luis D; Logarzo, Emilio; Mangani, Nicolas; Paolucci, Analia; Bonomini, Maria P

2018-05-01

His bundle pacing has shown to prevent detrimental effects from right ventricular apical pacing (RVA) and proved to resynchronize many conduction disturbances cases. However, the extent of His bundle pacing resynchronization is limited. An optimized stimulation waveform could expand this limit when implemented in His bundle pacing sets. In this work, we temporarily implemented RVA and Non-selective His bundle pacing with a biphasic anodal-first waveform (AF-nHB) and compared their effects against sinus rhythm (SR). Fifteen patients referred for electrophysiologic study with conduction disturbances, cardiomyopathy and ejection fraction below 35% were enrolled for the study. The following acute parameters were measured: QRS duration, left ventricular activation (RLVT), time of isovolumic contraction (IVCT), ejection fraction (EF), and dP/dtmax. QRS duration and RLVT decreased markedly under AF-nHB (SR: 169 ± 34 ms vs. nHB: 116 ± 31 ms, P < 0.0005) while RVA significantly increased QRS duration (SR: 169 ms vs. RVA: 198 ms, P < 0.05) and did not change RLVT (P = NS). Consistently, IVCT moderately decreased under AF-nHB (SR: 238 ms vs. RVA: 184 ms, P < 0.05 vs. SR) and dP/dtmax showed a 93.35 [mmHg] average increase under AF-nHB against SR. Also, T-wave inversions were observed during AF-nHB immediately after SR and RVA pacing suggesting the occurrence of cardiac memory. AF-nHB corrected bundle branch blocks in patients with severe conduction disturbances, even in those with dilated cardiomiopathy, outstanding from RVA. Also, the occurrence of cardiac memory during AF-nHB turned up as an observational finding of this study.

[Traumatic tricuspid insufficiency. Apropos of 2 cases].

PubMed

Ventre, F; Bertinchant, J P; Noblet, D; Frapier, J M; Carabasse, D; Nigond, J; Ledermann, B; Cohen, S; Joubert, P; Grolleau-Raoux, R

1995-06-01

The authors report two cases of tricuspid regurgitation by a ruptured anterior papillary muscle secondary to non-penetrating thoracic trauma. In the presence of suggestive clinical and electrocardiographic abnormalities (systolic murmur, right heart failure, right bundle branch block), echocardiography confirmed the tricuspid regurgitation, showed its mechanism and excluded any other intracardiac lesions. Tricuspid annuloplasty was performed in both cases because of the persistence of failure or degradation of the patient's clinical condition. Peroperative echocardiography was used to judge the quality of the surgical repair in both cases. Traumatic tricuspid regurgitation is a rare condition and the diagnosis is often delayed. Echocardiography is the investigation of choice and guides treatment which is essentially valvular repair in symptomatic patients.

Dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise: should we go beyond the guidelines?

PubMed

Laflamme, Emilie; Philippon, François; O'Connor, Kim; Sarrazin, Jean-François; Auffret, Vincent; Chauvette, Vincent; Dubois, Michelle; Voisine, Pierre; Bergeron, Sébastien; Sénéchal, Mario

2018-01-01

Guidelines for cardiac resynchronization therapy (CRT) have been established, but there may be a subgroup of patients not identified in these guidelines who may benefit from this therapy. We report a patient with a dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise successfully treated with CRT. Exercise testing should be considered in patients with left ventricular ejection fraction <35% and QRS <130 ms with severe heart failure symptoms that are unexplained by rest echocardiography evaluation in order to rule out ischemia and/or dynamic left ventricular dyssynchrony. In the presence of exercise-induced left ventricular bundle branch block, the implantation of CRT should be contemplated.

Left Ventricular Thrombus as a Complication of Clozapine-Induced Cardiomyopathy: A Case Report and Brief Literature Review.

PubMed

Malik, Shahbaz A; Malik, Sarah; Dowsley, Taylor F; Singh, Balwinder

2015-01-01

A 48-year-old male with history of schizoaffective disorder on clozapine presented with chest pain, dyspnea, and new left bundle branch block. He underwent coronary angiography, which revealed no atherosclerosis. The patient's workup was unrevealing for a cause for the cardiomyopathy and thus it was thought that clozapine was the offending agent. The patient was taken off clozapine and started on guideline directed heart failure therapy. During the course of hospitalization, he was also discovered to have a left ventricular (LV) thrombus for which he received anticoagulation. To our knowledge, this is the first case report of clozapine-induced cardiomyopathy complicated by a LV thrombus.

Pseudoaneurysm of the articular branch of the descending genicular artery following double-bundle anterior cruciate ligament reconstruction.

PubMed

Tsubosaka, Masanori; Matsushita, Takehiko; Kuroda, Ryosuke; Matsumoto, Tomoyuki; Kurosaka, Masahiro

2017-09-01

This report describes a case of a pseudoaneurysm of the articular branch of the descending genicular artery following double-bundle anterior cruciate ligament (ACL) reconstruction. An 18-year-old male received double-bundle ACL reconstruction. During ACL reconstruction, a far anteromedial portal was created for femoral tunnel drilling. The patient presented with pulsatile swelling on the medial side of the knee on the second post-operative day. The pseudoaneurysm was diagnosed using contrast computed tomography and Doppler ultrasonography and was subsequently treated by embolization with a microcatheter. Although a vascular injury is a very rare complication of knee arthroscopy, it should be considered a possibility in patients who undergo such procedures. V.

Carotid Space Mass Proximal to Vagus Nerve Causing Asystole and Syncope.

PubMed

Leviter, Julie; Wiznia, Daniel H

2016-01-01

Manipulation of vagal nerve rootlets, whether surgical or through mass effect of a neoplasm, can result in asystole and hypotension, accompanied by ST depression and right bundle branch block. There are few case reports of a neoplasm causing these effects, and this case describes a patient with such a mass presenting with syncopal episodes. A 43-year-old man with a past medical history of HIV, bipolar disorder, and epilepsy was admitted to the neurology service for a video electroencephalogram (vEEG) to characterize syncopal episodes that were felt to be epileptic in origin. During the study, he experienced symptoms of his typical aura, which correlated with a transient symptomatic high degree AV block on telemetry, and an absence of epileptic findings on vEEG. Magnetic Resonance Imaging (MRI) of the brain showed a mass in the left posterior carotid space at the skull base. The patient underwent permanent dual chamber MRI-compatible pacemaker placement for his heart block. His syncopal episodes resolved, but presyncopal symptoms persisted. We discuss the presentation and treatment of vagal neoplasms.

Synchronous ventricular pacing with direct capture of the atrioventricular conduction system: Functional anatomy, terminology, and challenges.

PubMed

Mulpuru, Siva K; Cha, Yong-Mei; Asirvatham, Samuel J

2016-11-01

Right ventricular apical pacing is associated with an increased incidence of heart failure, atrial fibrillation, and overall mortality. As a result, pacing the ventricles in a manner that closely mimics normal AV conduction with an intact His-Purkinje system has been explored. Recently, the sustainable benefits of selective His-bundle stimulation have been demonstrated and proposed as the preferred method of ventricular stimulation for appropriate patients. Ideally, conduction system pacing should be selective without myocardial capture, overcome distal bundle branch block when present, and not compromise tricuspid valve function. Contemporary literature on conduction system pacing is confusing largely because of inconsistent terminology and, at times, anatomically inaccurate terms used interchangeably for nonsynonymous anatomic sites. In this review, we discuss the functional anatomy of AV conduction access with specific emphasis on terminology, relationship to the membranous septum, tricuspid valve tissue, and proximity to atrial or ventricular myocardium. The potential benefits of each specific site as well as associated unique difficulties with those sites are described. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Prevalence of Chagas heart disease in a region endemic for Trypanosoma cruzi: evidence from a central Bolivian community.

PubMed

Yager, Jessica E; Lozano Beltran, Daniel F; Torrico, Faustino; Gilman, Robert H; Bern, Caryn

2015-09-01

Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population. We sought to determine the current prevalence of T. cruzi infection and associated Chagas heart disease in a Bolivian community endemic for T. cruzi. Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or electrocardiogram consistent with cardiac abnormalities were also scheduled for echocardiography. Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% vs. 0% for complete right bundle branch block and 10.4% vs. 1.9% for any bundle branch block; p = 0.008 and p < 0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure. Though almost one-third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease. Copyright © 2015 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.

Frequent Activation Delay-Induced Mechanical Dyssynchrony and Dysfunction in the Systemic Right Ventricle.

PubMed

Forsha, Daniel; Risum, Niels; Smith, P Brian; Kanter, Ronald J; Samad, Zainab; Barker, Piers; Kisslo, Joseph

2016-11-01

Patients with systemic right ventricles frequently experience progressive heart failure and conduction abnormalities leading to abnormal ventricular activation. Activation delay-induced mechanical dyssynchrony can contribute to ventricular failure and is identified by a classic strain pattern of paradoxical opposing wall motion that is an excellent predictor of response to cardiac resynchronization therapy in adults with left bundle branch block. The specific aims of this study were to compare right ventricular (RV) mechanics in an adult systemic right ventricle population versus control subjects, evaluate the feasibility of this RV strain pattern analysis, and determine the frequency of the classic pattern. Young adults (n = 25) with d-transposition of the great arteries, status post Mustard or Senning palliation (TGA-MS), were ambispectively enrolled and compared with healthy young adults (n = 30) who were prospectively enrolled. All subjects were imaged using novel three-apical view (18-segment) RV longitudinal speckle-tracking strain analysis (EchoPAC) and electrocardiographic data. Patients with TGA-MS had diminished RV global peak systolic strain compared with control subjects (-12.0 ± 4.0% vs -23.3 ± 2.3%, P < .001). Most patients with TGA-MS had intrinsic or left ventricular paced right bundle branch block. A classic pattern was present in 11 of 25 subjects (44%), but this pattern would have been missed in four of 11 based only on the RV four-chamber (six-segment) model. Only three subjects underwent cardiac resynchronization therapy. Both subjects who had the classic pattern responded to cardiac resynchronization therapy, whereas the one nonresponder did not have the classic pattern. Systemic right ventricles demonstrated decreased function and increased mechanical dyssynchrony. The classic pattern of activation delay-induced mechanical dyssynchrony was frequently seen in this TGA-MS population and associated with activation delays. This comprehensive RV approach demonstrated incremental value. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Predictors of Need for Permanent Pacemaker Implantation and Conduction Abnormalities With a Novel Self-expanding Transcatheter Heart Valve.

PubMed

Pellegrini, Costanza; Husser, Oliver; Kim, Won-Keun; Holzamer, Andreas; Walther, Thomas; Rheude, Tobias; Mayr, Nicola Patrick; Trenkwalder, Teresa; Joner, Michael; Michel, Jonathan; Chaustre, Fabian; Kastrati, Adnan; Schunkert, Heribert; Burgdorf, Christof; Hilker, Michael; Möllmann, Helge; Hengstenberg, Christian

2018-03-15

The incidence of permanent pacemaker implantation (PPI) and new conduction abnormalities (CA) with the ACURATE neo (Symetis S.A., Eclubens, Switzerland) has not been studied in detail. We aimed to analyze their predictors, evaluating patient- and device-related factors, including implantation depth and device-to-annulus ratio (DAR). Two analyses of a multicenter population were performed: new PPI in pacemaker-naive patients (n = 283), and PPI/new-CA in patients without prior CA or pacemaker (n = 232). A new PPI was required in 9.9% of patients, who had a higher body mass index, higher rate of right bundle branch block and bradycardia. Neither implantation depth nor DAR differed in patients with PPI compared with those without. In the multivariable analysis neither DAR (OR, 1.010; 95%CI, 0.967-1.055; P = .7) nor implantation depth (OR, 0.972; 95%CI, 0.743-1.272; P = .8) predicted PPI. Only high body mass index, bradycardia and right bundle branch block persisted as independent predictors. PPI/new-onset CA occurred in 22.8% of patients and was associated with a higher logistic EuroSCORE. Neither implantation depth nor DAR differed in patients with PPI/new-CA vs those without (7.3 ± 1.9 vs 7.1 ± 1.5mm; P = .6 and 41.0 ± 7.9 vs 42.2 ± 10.1%; P = .4). The only predictor of PPI/new-CA was a higher logistic EuroSCORE (OR, 1.039; 95%CI, [1.008-1.071]; P = .013). New PPI and new-onset CA rates were low with the ACURATE neo. These were mainly influenced by patient characteristics and not by device-depending factors. Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Association Between Global Longitudinal Strain and Cardiovascular Events in Patients With Left Bundle Branch Block Assessed Using Two-Dimensional Speckle-Tracking Echocardiography.

PubMed

Hwang, In-Chang; Cho, Goo-Yeong; Yoon, Yeonyee E; Park, Jin Joo

2018-01-01

The prognostic value of left ventricular (LV) global strain and twist in patients with left bundle branch block (LBBB) is not fully investigated. The aim of this study was to investigate the association between myocardial strain and twist and cardiovascular events in patients with LBBB, as assessed using two-dimensional speckle-tracking echocardiography. A total of 269 patients with LBBB (mean age, 69.5 ± 10.9 years; 46.8% men) were retrospectively identified. Using speckle-tracking, LV global longitudinal strain (GLS), global circumferential strain, and twist were measured. Association between LV global function and a composite of cardiovascular mortality and hospitalization for heart failure was compared with clinical risk factors, LV ejection fraction (LVEF), and other echocardiographic parameters. During a median of 27.5 months (interquartile range, 12.8-43.9 months), the composite end point occurred in 55 patients (20.4%). In univariate analyses, diabetes mellitus, chronic kidney disease, ischemic etiology of LBBB, dilated left atrium, reduced LVEF, dilated left ventricle, and impaired LV global strain (GLS > -12.2%, global circumferential strain > -11.8%, and twist < 6.5°) showed associations with the composite end point. In multivariate analyses, GLS was significantly associated with the composite end point (adjusted hazard ratio, 4.697; 95% CI, 1.344-16.413; P = .015), whereas global circumferential strain, twist, and LVEF were not. GLS showed an additive association with poor prognosis over clinical risk factors and other echocardiographic parameters, including LVEF. Patients with preserved LVEFs (≥40%) but impaired GLS (>-12.2%) had a larger number of clinical events than those with impaired LVEFs but preserved GLS. Among patients with LBBB, GLS can provide better risk stratification than LVEF or other echocardiographic parameters. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Patients with left bundle branch block and left axis deviation show a specific left ventricular asynchrony pattern: Implications for left ventricular lead placement during CRT implantation.

PubMed

Sciarra, Luigi; Golia, Paolo; Palamà, Zefferino; Scarà, Antonio; De Ruvo, Ermenegildo; Borrelli, Alessio; Martino, Anna Maria; Minati, Monia; Fagagnini, Alessandro; Tota, Claudia; De Luca, Lucia; Grieco, Domenico; Delise, Pietro; Calò, Leonardo

Left bundle branch block (LBBB) and left axis deviation (LAD) patients may have poor response to resynchronization therapy (CRT). We sought to assess if LBBB and LAD patients show a specific pattern of mechanical asynchrony. CRT candidates with non-ischemic cardiomyopathy and LBBB were categorized as having normal QRS axis (within -30° and +90°) or LAD (within -30° and -90°). Patients underwent tissue Doppler imaging (TDI) to measure time interval between onset of QRS complex and peak systolic velocity in ejection period (Q-peak) at basal segments of septal, inferior, lateral and anterior walls, as expression of local timing of mechanical activation. Thirty patients (mean age 70.6years; 19 males) were included. Mean left ventricular ejection fraction was 0.28±0.06. Mean QRS duration was 172.5±13.9ms. Fifteen patients showed LBBB with LAD (QRS duration 173±14; EF 0.27±0.06). The other 15 patients had LBBB with a normal QRS axis (QRS duration 172±14; EF 0.29±0.05). Among patients with LAD, Q-peak interval was significantly longer at the anterior wall in comparison to each other walls (septal 201±46ms, inferior 242±58ms, lateral 267±45ms, anterior 302±50ms; p<0.0001). Conversely, in patients without LAD Q-peak interval was longer at lateral wall, when compared to each other (septal 228±65ms, inferior 250±64ms, lateral 328±98ms, anterior 291±86ms; p<0.0001). Patients with heart failure, presenting LBBB and LAD, show a specific pattern of ventricular asynchrony, with latest activation at anterior wall. This finding could affect target vessel selection during CRT procedures in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Prevalence and clinical significance of left bundle branch block according to classical or strict definition criteria in permanent pacemaker patients.

PubMed

Mazza, Andrea; Bendini, Maria Grazia; De Cristofaro, Raffaele; Lovecchio, Mariolina; Valsecchi, Sergio; Leggio, Massimo; Boriani, Giuseppe

2017-06-01

Previous studies have shown that the presence of left bundle branch block (LBBB) is associated with an increased risk of cardiac mortality and heart failure (HF). Recently, new criteria to define strict LBBB have been proposed: QRS duration ≥140 ms for men and ≥130 ms for women, along with mid-QRS notching or slurring in ≥2 contiguous leads. We assessed the prevalence and prognostic significance of LBBB according to classical (QRS duration ≥120ms) and strict criteria in permanent pacemaker patients. We retrospectively enrolled 723 consecutive patients who had undergone single- or dual-chamber pacemaker implantation at the study center from July 2002 to December 2014. Patients with a left ventricular ejection fraction ≤35% or a prior diagnosis of HF were excluded. LBBB was reported in 54 (7%) patients, and strict-LBBB in 15 (2%) patients. During a median follow-up of 48 months (range, 18-92 months), 147 (20%) patients reached the combined endpoint of death or HF hospitalization. Patients with LBBB and those with strict-LBBB displayed significantly higher rates of death or HF hospitalization (log-rank test, all P < 0.0001). In particular, strict-LBBB was associated with the worst outcome. The presence of LBBB according to classical definition criteria (hazard ratio [HR] = 1.98, confidence interval [CI]: 1.23-3.19, P = 0.005) and to strict criteria (HR = 2.20; CI: 1.04-4.65; P = 0.039) were both confirmed as independent predictors of death or HF hospitalization after adjustment for relevant clinical covariates. Among patients who had undergone standard pacemaker implantation, the prevalence of LBBB was 7% according to classical definition criteria and 2% according to strict criteria. The presence of LBBB, and particularly of strict-LBBB, at the baseline predicted a poor outcome in terms of death or HF hospitalization. © 2017 Wiley Periodicals, Inc.

Transfer of patients with ST-elevation myocardial infarction for primary percutaneous coronary intervention: a province-wide evaluation of "door-in to door-out" delays at the first hospital.

PubMed

Lambert, Laurie J; Brown, Kevin A; Boothroyd, Lucy J; Segal, Eli; Maire, Sébastien; Kouz, Simon; Ross, Dave; Harvey, Richard; Rinfret, Stéphane; Xiao, Yongling; Nasmith, James; Bogaty, Peter

2014-06-24

Interhospital transfer of patients with ST-elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PPCI) is associated with longer delays to reperfusion, related in part to turnaround ("door in" to "door out," or DIDO) time at the initial hospital. As part of a systematic, province-wide evaluation of STEMI care, we examined DIDO times and associations with patient, hospital, and process-of-care factors. We performed medical chart review for STEMI patients transferred for PPCI during a 6-month period (October 1, 2008, through March 31, 2009) and linked these data to ambulance service databases. Two core laboratory cardiologists reviewed presenting ECGs to identify left bundle-branch block and, in the absence of left bundle-branch block, definite STEMI (according to both cardiologists) or an ambiguous reading. Median DIDO time was 51 minutes (25th to 75th percentile: 35-82 minutes); 14.1% of the 988 patients had a timely DIDO interval (≤30 minutes as recommended by guidelines). The data-to-decision delay was the major contributor to DIDO time. Female sex, more comorbidities, longer symptom duration, arrival by means other than ambulance, arrival at a hospital not exclusively transferring for PPCI, arrival at a center with a low STEMI volume, and an ambiguous ECG were independently associated with longer DIDO time. When turnaround was timely, 70% of patients received timely PPCI (door-to-device time ≤90 minutes) versus 14% if turnaround was not timely (P<0.0001). Benchmark DIDO times for STEMI patients transferred for PPCI were rarely achieved. Interventions aimed at facilitating the transfer decision, particularly in cases of ECGs that are difficult to interpret, are likely to have the best impact on reducing delay to reperfusion. © 2014 American Heart Association, Inc.

Comparison of the QRS Complex, ST-Segment, and T-Wave Among Patients with Left Bundle Branch Block with and without Acute Myocardial Infarction.

PubMed

Dodd, Kenneth W; Elm, Kendra D; Smith, Stephen W

2016-07-01

The modified Sgarbossa criteria have been validated as a rule for diagnosis of acute coronary occlusion (ACO) in left bundle branch block (LBBB). However, no analysis has been done on differences in the QRS complex, T-wave, or ST-segment concordance of < 1 mm in the derivation or validation studies. Furthermore, there was no comparison of patients with acute myocardial infarction (AMI) but without ACO (i.e., non-ST-elevation myocardial infarction [non-STEMI]) to patients with ACO or without AMI (no MI). We compare findings involving the QRS amplitude, ST-segment morphology, ST-concordance < 1 mm, and T-waves in patients with LBBB with ACO, non-STEMI, and no MI. Retrospectively, emergency department patients were identified with LBBB and ischemic symptoms but no MI, with angiographically proven ACO, and with non-STEMI. ACO, non-STEMI, and no MI groups consisted of 33, 24, and 105 patients. The sum of the maximum deflection of the QRS amplitude across all leads (ΣQRS) was smaller in patients with ACO than those without ACO (101.5 mm vs. 132.5 mm; p < 0.0001) and a cutoff of ΣQRS < 90 mm was 92% specific. For ACO, non-concave ST-segment morphology was 91% specific, any ST concordance ≥ 1 mm was 95% specific, and any ST concordance ≥ 0.5 mm was 94% sensitive. For non-STEMI, terminal T-wave concordance, analogous to biphasic T-waves, was moderately sensitive at 79%. We found differences in QRS amplitude, ST-segment morphology, and T-waves between patients with LBBB and ACO, non-STEMI, and no MI. However, none of these criteria outperformed the modified Sgarbossa criteria for diagnosis of ACO in LBBB. Copyright © 2016 Elsevier Inc. All rights reserved.

Arrhythmias after transcatheter closure of perimembranous ventricular septal defects with a modified double-disk occluder: early and long-term results.

PubMed

Li, Pan; Zhao, Xian-xian; Zheng, Xing; Qin, Yong-wen

2012-07-01

With the development of interventional techniques and devices, transcatheter closure of perimembranous ventricular septal defect has been widely performed. However, there has been a lack of long-term follow-up results about postoperative ECG changes of PmVSD patients. We report our experience of early and late arrhythmias after transcatheter closure of PmVSD with a modified double-disk occluder (MDVO). We performed a retrospective review of 79 patients (47 males, 32 females) between September 2002 and May 2007 who underwent transcatheter closure of perimembranous ventricular septal defect. Symmetric and asymmetric PmVSD occluders were used. The diameter of the evaluated defects ranged from 3 to 12 mm, as measured by TTE and 3 to 15 mm by left ventriculography. Most cases of PmVSD were treated successfully with a single procedure, resulting in a successful closure rate of 97% (77/79 patients). There was no death in any of the patients. After the operation, 79 patients were followed-up for a range of 10-76 months (35.3 ± 17.4 months). In this series, 11 cases of incomplete right bundle branch block and five cases of complete right bundle branch block occurred during the early period after operation. During long-term follow-up, these issues declined in prevalence to five and four cases, respectively. Moreover, reversible third-degree AVB occurred during closure or after the procedure, and two of the three patients with reversible AVB received a temporary heart pacemaker implantation. These patients recovered 1 h, 6 days, and 9 days later, respectively. During 10-76 months of follow-up, no complications occurred in any of the patients, including residual shunt, severe aortic valve, or tricuspid valve regurgitation. Device closure of perimembranous ventricular septal defects with a modified double-disk occluder (MDVO) resulted in excellent closure rates and acceptably low arrhythmia rates.

Impact of New-Onset Left Bundle Branch Block and Periprocedural Permanent Pacemaker Implantation on Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

PubMed

Regueiro, Ander; Abdul-Jawad Altisent, Omar; Del Trigo, María; Campelo-Parada, Francisco; Puri, Rishi; Urena, Marina; Philippon, François; Rodés-Cabau, Josep

2016-05-01

Available data on the clinical impact of new-onset left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR) remains controversial. We aimed to evaluate the impact of (1) periprocedural new-onset LBBB or PPI post-TAVR on cardiac mortality and all-cause 1-year mortality and (2) new-onset LBBB on the need for PPI at 1-year follow-up. We performed a systematic search from PubMed and EMBASE databases for studies reporting raw data on new-onset LBBB post-TAVR and the need for PPI or mortality at 1-year follow-up, or on 1-year mortality according to the need for periprocedural PPI post-TAVR. Data from 17 studies, including 4756 patients (8 studies) and 7032 patients (11 studies) for the evaluation of the impact of new-onset LBBB and periprocedural PPI post-TAVR were sourced, respectively (with 2 studies used for both outcomes). New-onset LBBB post-TAVR was associated with a higher risk of PPI (risk ratio [RR], 2.18; 95% confidence interval [CI], 1.28-3.70) and cardiac death (RR, 1.39; 95% CI, 1.04-1.86) during follow-up, as well with a tendency toward an increase in all-cause mortality (RR, 1.21; 95% CI, 0.98-1.50). Periprocedural PPI post-TAVR was not associated with any increased risk of all-cause mortality at 1 year (RR, 1.03; 95% CI, 0.9-1.18), yet a tendency toward a protective effect on cardiac death was observed (RR, 0.78; 95% CI, 0.60-1.03). New-onset LBBB post-TAVR is a marker of an increased risk of cardiac death and need for PPI at 1-year follow-up. The need for PPI early post-TAVR did not increase the risk of death. © 2016 American Heart Association, Inc.

ECG parameters predict left ventricular conduction delay in patients with left ventricular dysfunction.

PubMed

Pastore, Gianni; Maines, Massimiliano; Marcantoni, Lina; Zanon, Francesco; Noventa, Franco; Corbucci, Giorgio; Baracca, Enrico; Aggio, Silvio; Picariello, Claudio; Lanza, Daniela; Rigatelli, Gianluca; Carraro, Mauro; Roncon, Loris; Barold, S Serge

2016-12-01

Estimating left ventricular electrical delay (Q-LV) from a 12-lead ECG may be important in evaluating cardiac resynchronization therapy (CRT). The purpose of this study was to assess the impact of Q-LV interval on ECG configuration. One hundred ninety-two consecutive patients undergoing CRT implantation were divided electrocardiographically into 3 groups: left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific intraventricular conduction delay (IVCD). The IVCD group was further subdivided into 81 patients with left (L)-IVCD and 15 patients with right (R)-IVCD (resembling RBBB, but without S wave in leads I and aVL). The Q-LV interval in the different groups and the relationship between ECG parameters and the maximum Q-LV interval were analyzed. Patients with LBBB presented a long Q-LV interval (147.7 ± 14.6 ms, all exceeding cutoff value of 110 ms), whereas RBBB patients presented a very short Q-LV interval (75.2 ± 16.3 ms, all <110 ms). Patients with an IVCD displayed a wide range of Q-LV intervals. In L-IVCD, mid-QRS notching/slurring showed the strongest correlation with a longer Q-LV interval, followed, in decreasing order, by QRS duration >150 ms and intrinsicoid deflection >60 ms. Isolated mid-QRS notching/slurring predicted Q-LV interval >110 ms in 68% of patients. The R-IVCD group presented an unexpectedly longer Q-LV interval (127.0 ± 12.5 ms; 13/15 patients had Q-LV >110 ms). Patients with LBBB have a very prolonged Q-LV interval. Mid-QRS notching in lateral leads strongly predicts a longer Q-LV interval in L-IVCD patients. Patients with R-IVCD constitute a subgroup of patients with a long Q-LV interval. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Are 12-lead ECG findings associated with the risk of cardiovascular events after ischemic stroke in young adults?

PubMed

Pirinen, Jani; Putaala, Jukka; Aarnio, Karoliina; Aro, Aapo L; Sinisalo, Juha; Kaste, Markku; Haapaniemi, Elena; Tatlisumak, Turgut; Lehto, Mika

2016-11-01

Ischemic stroke (IS) in a young patient is a disaster and recurrent cardiovascular events could add further impairment. Identifying patients with high risk of such events is therefore important. The prognostic relevance of ECG for this population is unknown. A total of 690 IS patients aged 15-49 years were included. A 12-lead ECG was obtained 1-14 d after the onset of stroke. We adjusted for demographic factors, comorbidities, and stroke characteristics, Cox regression models were used to identify independent ECG parameters associated with long-term risks of (1) any cardiovascular event, (2) cardiac events, and (3) recurrent stroke. Median follow-up time was 8.8 years. About 26.4% of patients experienced a cardiovascular event, 14.5% had cardiac events, and 14.6% recurrent strokes. ECG parameters associated with recurrent cardiovascular events were bundle branch blocks, P-terminal force, left ventricular hypertrophy, and a broader QRS complex. Furthermore, more leftward P-wave axis, prolonged QTc, and P-wave duration >120 ms were associated with increased risks of cardiac events. No ECG parameters were independently associated with recurrent stroke. A 12-lead ECG can be used for risk prediction of cardiovascular events but not for recurrent stroke in young IS patients. KEY MESSAGES ECG is an easy, inexpensive, and useful tool for identifying young ischemic stroke patients with a high risk for recurrent cardiovascular events and it has a statistically significant association with these events even after adjusting for confounding factors. Bundle branch blocks, P-terminal force, broader QRS complex, LVH according to Cornell voltage duration criteria, more leftward P-wave axis, prolonged QTc, and P-wave duration >120 ms are predictors for future cardiovascular or cardiac events in these patients. No ECG parameters were independently associated with recurrent stroke.

Sodium channel blockade with QRS widening after an escitalopram overdose.

PubMed

Schreffler, Susan M; Marraffa, Jeanna M; Stork, Christine M; Mackey, Jennifer

2013-09-01

Escitalopram is rarely associated with prolongation of the QTc interval; however, there are no reported cases of QRS complex widening associated with escitalopram overdose. We report a case of a patient who presented with both QRS complex widening and QTc interval prolongation after an escitalopram overdose. A 16-year-old girl presented to the emergency department after ingestion of escitalopram, tramadol/acetaminophen, and hydrocodone/acetaminophen. Laboratory results were significant for 4-hour acetaminophen 21.1 μg/mL. Serum electrolytes including potassium, magnesium, and calcium were all normal. Initial electrocardiogram (ECG) revealed a widened QRS with an incomplete right bundle branch pattern. After administration of 100-mEq sodium bicarbonate, a repeat ECG revealed narrowing of the QRS complex and a prolonged QTc interval. Magnesium sulfate 2 g intravenous and sodium bicarbonate drip were initiated. A repeat ECG, 1 hour after the second, revealed normalization of the QRS complex and QTc interval. Prolongation of the QTc interval is an expected effect of escitalopram. Both escitalopram and citalopram are metabolized to the cardiotoxic metabolite S-didesmethylcitalopram and didesmethylcitalopram, respectively, which have been implicated in numerous cardiac abnormalities including widening of the QRS complex. Although never previously described with escitalopram, this mechanism provides a reasonable explanation for the QRS complex widening and incomplete right bundle branch block that occurred in our patient. Both QRS complex widening and QTc interval prolongation should be monitored in cases of escitalopram and citalopram overdoses.

Method of fabricating high-density hermetic electrical feedthroughs using insulated wire bundles

DOEpatents

Shah, Kedar G.; Benett, William J.; Pannu, Satinderpall S.

2016-05-10

A method of fabricating electrical feedthroughs coats of a plurality of electrically conductive wires with an electrically insulating material and bundles the coated wires together in a substantially parallel arrangement. The bundled coated wires are secured to each other by joining the electrically insulating material of adjacent wires together to form a monolithic block which is then cut transverse to the wires to produce a block section having opposing first and second sides with a plurality of electrically conductive feedthroughs extending between them.

11C-4DST PET/CT Imaging of Cardiac Sarcoidosis: Comparison With 18F-FDG and Cardiac MRI.

PubMed

Hotta, Masatoshi; Minamimoto, Ryogo; Kubota, Shuji; Awaya, Toru; Hiroi, Yukio

2018-06-01

A 75-year-old woman with a history of sarcoidosis presenting with low cardiac output and complete right bundle-branch block underwent 4'-[methyl-C]-thiothymidine (4DST) PET/CT after cardiac MRI and FDG PET/CT for the evaluation of suspected cardiac sarcoidosis (CS) before treatment. Cardiac MRI revealed late gadolinium enhancement on the anterior-to-lateral and posterior wall, indicating CS. FDG uptake was shown on the anterior-to-lateral wall, but not on the posterior wall. In contrast, 4DST uptake was demonstrated on both anterior-to-lateral and posterior walls. Use of 4DST appears promising for detecting CS without dietary restriction, due to the lack of physiological uptake in myocardium.

Magnetic resonance imaging reveals functional anatomy and biomechanics of a living dragon tree

PubMed Central

Hesse, Linnea; Masselter, Tom; Leupold, Jochen; Spengler, Nils; Speck, Thomas; Korvink, Jan Gerrit

2016-01-01

Magnetic resonance imaging (MRI) was used to gain in vivo insight into load-induced displacements of inner plant tissues making a non-invasive and non-destructive stress and strain analysis possible. The central aim of this study was the identification of a possible load-adapted orientation of the vascular bundles and their fibre caps as the mechanically relevant tissue in branch-stem-attachments of Dracaena marginata. The complex three-dimensional deformations that occur during mechanical loading can be analysed on the basis of quasi-three-dimensional data representations of the outer surface, the inner tissue arrangement (meristem and vascular system), and the course of single vascular bundles within the branch-stem-attachment region. In addition, deformations of vascular bundles could be quantified manually and by using digital image correlation software. This combination of qualitative and quantitative stress and strain analysis leads to an improved understanding of the functional morphology and biomechanics of D. marginata, a plant that is used as a model organism for optimizing branched technical fibre-reinforced lightweight trusses in order to increase their load bearing capacity. PMID:27604526

Cardiac rhythm and pacemaking abnormalities in patients affected by endemic pemphigus in Colombia may be the result of deposition of autoantibodies, complement, fibrinogen, and other molecules.

PubMed

Abreu Velez, Ana Maria; Howard, Michael S; Velazquez-Velez, Jorge Enrique

2018-05-01

We previously showed that one-third of patients affected by endemic pemphigus foliaceus in El Bagre, Colombia (El Bagre-EPF), display autoreactivity to the heart. The purpose of this study was to investigate rhythm disturbances with the presence of autoantibodies and correlate them with ECG changes in these patients. We performed a study comparing 30 patients and 30 controls from the endemic area, matched by demographics, including age, sex, weight, work activities, and comorbidities. ECG as well as direct and indirect immunofluorescence, immunohistochemistry, and confocal microscopic studies focusing on cardiac node abnormalities were performed. Autopsies of 7 patients also were reviewed. The main ECG abnormalities seen in the El Bagre-EPF patients were sinus bradycardia (in one-half), followed by left bundle branch block, left posterior fascicular block, and left anterior fascicular block compared with the controls. One-third of the patients displayed polyclonal autoantibodies against the sinoatrial and/or AV nodes and the His bundle correlating with rhythm anomalies and delays in the cardiac conduction system (P <.01). The patient antibodies colocalized with commercial antibodies to desmoplakins I and II, p0071, armadillo repeat gene deleted in velo-cardio-facial syndrome (ARVCF), and myocardium-enriched zonula occludens-1-associated protein (MYZAP; Progen Biotechnik) (P <.01). One-third of the patients affected by El Bagre-EPF have rhythm abnormalities that slow the conduction of impulses in cardiac nodes and the cardiac conduction system. These abnormalities likely occur as a result of deposition of autoantibodies, complement, and other inflammatory molecules. We show for the first time that MYZAP is present in cardiac nodes. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Electrical cardioversion

PubMed Central

Sucu, Murat; Davutoglu, Vedat; Ozer, Orhan

2009-01-01

External electrical cardioversion was first performed in the 1950s. Urgent or elective cardioversions have specific advantages, such as termination of atrial and ventricular tachycardia and recovery of sinus rhythm. Electrical cardioversion is life-saving when applied in urgent circumstances. The succcess rate is increased by accurate tachycardia diagnosis, careful patient selection, adequate electrode (paddles) application, determination of the optimal energy and anesthesia levels, prevention of embolic events and arrythmia recurrence and airway conservation while minimizing possible complications. Potential complications include ventricular fibrillation due to general anesthesia or lack of synchronization between the direct current (DC) shock and the QRS complex, thromboembolus due to insufficient anticoagulant therapy, non-sustained VT, atrial arrhythmia, heart block, bradycardia, transient left bundle branch block, myocardial necrosis, myocardial dysfunction, transient hypotension, pulmonary edema and skin burn. Electrical cardioversion performed in patients with a pacemaker or an incompatible cardioverter defibrillator may lead to dysfunction, namely acute or chronic changes in the pacing or sensitivity threshold. Although this procedure appears fairly simple, serious consequences might occur if inappropriately performed. PMID:19448376

ELIGULUM-A Regulates Lateral Branch and Leaf Development in Barley1[OPEN

PubMed Central

Haaning, Allison; Bilgic, Hatice

2018-01-01

The shoot apical and axillary meristems control shoot development, effectively influencing lateral branch and leaf formation. The barley (Hordeum vulgare) uniculm2 (cul2) mutation blocks axillary meristem development, and mutant plants lack lateral branches (tillers) that normally develop from the crown. A genetic screen for cul2 suppressors recovered two recessive alleles of ELIGULUM-A (ELI-A) that partially rescued the cul2 tillering phenotype. Mutations in ELI-A produce shorter plants with fewer tillers and disrupt the leaf blade-sheath boundary, producing liguleless leaves and reduced secondary cell wall development in stems and leaves. ELI-A is predicted to encode an unannotated protein containing an RNaseH-like domain that is conserved in land plants. ELI-A transcripts accumulate at the preligule boundary, the developing ligule, leaf margins, cells destined to develop secondary cell walls, and cells surrounding leaf vascular bundles. Recent studies have identified regulatory similarities between boundary development in leaves and lateral organs. Interestingly, we observed ELI-A transcripts at the preligule boundary, suggesting that ELI-A contributes to boundary formation between the blade and sheath. However, we did not observe ELI-A transcripts at the axillary meristem boundary in leaf axils, suggesting that ELI-A is not involved in boundary development for axillary meristem development. Our results show that ELI-A contributes to leaf and lateral branch development by acting as a boundary gene during ligule development but not during lateral branch development. PMID:29440592

Actin filament bundling by fimbrin is important for endocytosis, cytokinesis, and polarization in fission yeast.

PubMed

Skau, Colleen T; Courson, David S; Bestul, Andrew J; Winkelman, Jonathan D; Rock, Ronald S; Sirotkin, Vladimir; Kovar, David R

2011-07-29

Through the coordinated action of diverse actin-binding proteins, cells simultaneously assemble actin filaments with distinct architectures and dynamics to drive different processes. Actin filament cross-linking proteins organize filaments into higher order networks, although the requirement of cross-linking activity in cells has largely been assumed rather than directly tested. Fission yeast Schizosaccharomyces pombe assembles actin into three discrete structures: endocytic actin patches, polarizing actin cables, and the cytokinetic contractile ring. The fission yeast filament cross-linker fimbrin Fim1 primarily localizes to Arp2/3 complex-nucleated branched filaments of the actin patch and by a lesser amount to bundles of linear antiparallel filaments in the contractile ring. It is unclear whether Fim1 associates with bundles of parallel filaments in actin cables. We previously discovered that a principal role of Fim1 is to control localization of tropomyosin Cdc8, thereby facilitating cofilin-mediated filament turnover. Therefore, we hypothesized that the bundling ability of Fim1 is dispensable for actin patches but is important for the contractile ring and possibly actin cables. By directly visualizing actin filament assembly using total internal reflection fluorescence microscopy, we determined that Fim1 bundles filaments in both parallel and antiparallel orientations and efficiently bundles Arp2/3 complex-branched filaments in the absence but not the presence of actin capping protein. Examination of cells exclusively expressing a truncated version of Fim1 that can bind but not bundle actin filaments revealed that bundling activity of Fim1 is in fact important for all three actin structures. Therefore, fimbrin Fim1 has diverse roles as both a filament "gatekeeper" and as a filament cross-linker.

Cardiac resynchronisation therapy in the presence of left-to-right intracardiac shunting: more good than harm?

PubMed

Kyu, Kyu; Seow, Swee Chong; Wong, Raymond; Kojodjojo, Pipin

2016-03-17

An elderly Chinese man with moderately impaired left ventricular function, left bundle branch block and ST-elevation myocardial infarction complicated by ventricular septal rupture had class IV heart failure symptoms refractory to medical and surgical interventions. As a treatment of last resort, a cardiac resynchronisation therapy (CRT) pacemaker was implanted apprehensively, as preoperative concerns were raised whether CRT could exacerbate left-to-right shunting, hence negating the potential benefits of CRT. Introduction of CRT significantly improved the patient's haemodynamic status and symptoms, allowing for successful discharge home. To the best of our knowledge, this is the first report of a patient with severely symptomatic acute heart failure, widened QRS and active left-to-right intracardiac shunting, treated successfully with CRT. 2016 BMJ Publishing Group Ltd.

Presenting Lexical Bundles for Explicit Noticing with Schematic Linguistic Representation

ERIC Educational Resources Information Center

Thomson, Haidee Elizabeth

2016-01-01

Lexical bundles are essential for fluency, but their incompleteness is a stumbling block for learners. In this study, two presentation methods to increase awareness of lexical bundles through explicit noticing are explored and compared with incidental exposure. The three conditions in this study were as follows: noticing with schematic linguistic…

Morphological study of the atrioventricular conduction system and Purkinje fibers in yak.

PubMed

Duan, Deyong; Yu, Sijiu; Cui, Yan; Li, Chaoxu

2017-07-01

We studied the morphology of the atrioventricular conduction system (AVCS) and Purkinje fibers of the yak. Light and transmission electron microscopy were used to study the histological features of AVCS. The distributional characteristics of the His-bundle, the left bundle branch (LBB), right bundle branch (RBB), and Purkinje fiber network of yak hearts were examined using gross dissection, ink injection, and ABS casting. The results showed that the atrioventricular node (AVN) of yak located in the right side of interatrial septum and had a flattened ovoid shape. The AVN of yak is composed of the slender, interweaving cells formed almost entirely of the transitional cells (T-cells). The His-bundle extended from the AVN, and split into left LBB and RBB at the crest of the interventricular septum. The LBB descended along the left side of interventricular septum. At approximately the upper 1/3 of the interventricular septum, the LBB typically divided into three branches. The RBB ran under the endocardium of the right side of interventricular septum, and extended to the base of septal papillary muscle, passed into the moderator band, crossed the right ventricular cavity to reach the base of anterior papillary muscle, and divided into four fascicles under the subendocardial layer. The Purkinje fibers in the ventricle formed a complex spatial network. The distributional and cellular component characteristics of the AVCS and Purkinje fibers ensured normal cardiac function. © 2017 Wiley Periodicals, Inc.

Intramuscular communicating branches in the flexor digitorum profundus: dissection and Sihler's staining.

PubMed

Won, Sung-Yoon; Choi, Da-Yae; Lee, Jae-Gi; Yoon, Kwan-Hyun; Kwak, Hyun-Ho; Hu, Kyung-Seok; Kim, Hee-Jin

2010-03-01

This study was designed to clarify the anatomy of the intramuscular communicating branch (ICb) between the median and ulnar nerves in the flexor digitorum profundus (FDP), and morphologically demonstrate the location of connection. Twenty Korean cadavers were dissected and a further 8 were subjected to modified Sihler's staining to investigate the pattern of innervation of the ICb and the location of its communicating points in muscle. The median and ulnar nerves divided into small branches before entering FDP muscle. Of these small branches, one or two met inside the muscle. This communicating pattern could be classified into three types: type I, communicating branches in both the proximal and distal regions; type II, at least one communicating branch in the proximal region; type III, at least one communicating branch in the distal region. Of 20 dissected specimens, no case of type I was observed, but 3 cases of type II and 15 cases of type III were found. No ICbs at all were found in two of the dissected specimens. In eight stained specimens, one was classified as type I, two as type II, and five as type III. The proximal communicating branches were located at 34.1% from the interepicondylar line, inside the third muscle bundle. The distal communicating branches were located at 66.0% from the interepicondylar line, between third and fourth muscle bundles. These findings could provide critical anatomical information regarding the nerve distribution of FDP focused on the ICbs.

Quantitative Analysis of Electro-Anatomical Maps: Application to an Experimental Model of Left Bundle Branch Block/Cardiac Resynchronization Therapy

PubMed Central

Duchateau, Nicolas; Kostantyn Butakov, Constantine Butakoff; Andreu, David; Fernández-Armenta, Juan; Bijnens, Bart; Berruezo, Antonio; Sitges, Marta; Camara, Oscar

2017-01-01

Electro-anatomical maps (EAMs) are commonly acquired in clinical routine for guiding ablation therapies. They provide voltage and activation time information on a 3-D anatomical mesh representation, making them useful for analyzing the electrical activation patterns in specific pathologies. However, the variability between the different acquisitions and anatomies hampers the comparison between different maps. This paper presents two contributions for the analysis of electrical patterns in EAM data from biventricular surfaces of cardiac chambers. The first contribution is an integrated automatic 2-D disk representation (2-D bull’s eye plot) of the left ventricle (LV) and right ventricle (RV) obtained with a quasi-conformal mapping from the 3-D EAM meshes, that allows an analysis of cardiac resynchronization therapy (CRT) lead positioning, interpretation of global (total activation time), and local indices (local activation time (LAT), surrogates of conduction velocity, inter-ventricular, and transmural delays) that characterize changes in the electrical activation pattern. The second contribution is a set of indices derived from the electrical activation: speed maps, computed from LAT values, to study the electrical wave propagation, and histograms of isochrones to analyze regional electrical heterogeneities in the ventricles. We have applied the proposed methods to look for the underlying physiological mechanisms of left bundle branch block (LBBB) and CRT, with the goal of optimizing the therapy by improving CRT response. To better illustrate the benefits of the proposed tools, we created a set of synthetically generated and fully controlled activation patterns, where the proposed representation and indices were validated. Then, the proposed analysis tools are used to analyze EAM data from an experimental swine model of induced LBBB with an implanted CRT device. We have analyzed and compared the electrical activation patterns at baseline, LBBB, and CRT stages in four animals: two without any structural disease and two with an induced infarction. By relating the CRT lead location with electrical dyssynchrony, we evaluated current hypotheses about lead placement in CRT and showed that optimal pacing sites should target the RV lead close to the apex and the LV one distant from it. PMID:29164019

Usefulness of the admission electrocardiogram to predict long-term outcomes after non-ST-elevation acute coronary syndrome (from the FRISC II, ICTUS, and RITA-3 [FIR] Trials).

PubMed

Damman, Peter; Holmvang, Lene; Tijssen, Jan G P; Lagerqvist, Bo; Clayton, Tim C; Pocock, Stuart J; Windhausen, Fons; Hirsch, Alexander; Fox, Keith A A; Wallentin, Lars; de Winter, Robbert J

2012-01-01

The aim of this study was to evaluate the independent prognostic value of qualitative and quantitative admission electrocardiographic (ECG) analysis regarding long-term outcomes after non-ST-segment elevation acute coronary syndromes (NSTE-ACS). From the Fragmin and Fast Revascularization During Instability in Coronary Artery Disease (FRISC II), Invasive Versus Conservative Treatment in Unstable Coronary Syndromes (ICTUS), and Randomized Intervention Trial of Unstable Angina 3 (RITA-3) patient-pooled database, 5,420 patients with NSTE-ACS with qualitative ECG data, of whom 2,901 had quantitative data, were included in this analysis. The main outcome was 5-year cardiovascular death or myocardial infarction. Hazard ratios (HRs) were calculated with Cox regression models, and adjustments were made for established outcome predictors. The additional discriminative value was assessed with the category-less net reclassification improvement and integrated discrimination improvement indexes. In the 5,420 patients, the presence of ST-segment depression (≥1 mm; adjusted HR 1.43, 95% confidence interval [CI] 1.25 to 1.63) and left bundle branch block (adjusted HR 1.64, 95% CI 1.18 to 2.28) were independently associated with long-term cardiovascular death or myocardial infarction. Risk increases were short and long term. On quantitative ECG analysis, cumulative ST-segment depression (≥5 mm; adjusted HR 1.34, 95% CI 1.05 to 1.70), the presence of left bundle branch block (adjusted HR 2.15, 95% CI 1.36 to 3.40) or ≥6 leads with inverse T waves (adjusted HR 1.22, 95% CI 0.97 to 1.55) was independently associated with long-term outcomes. No interaction was observed with treatment strategy. No improvements in net reclassification improvement and integrated discrimination improvement were observed after the addition of quantitative characteristics to a model including qualitative characteristics. In conclusion, in the FRISC II, ICTUS, and RITA-3 NSTE-ACS patient-pooled data set, admission ECG characteristics provided long-term prognostic value for cardiovascular death or myocardial infarction. Quantitative ECG characteristics provided no incremental discrimination compared to qualitative data. Copyright © 2012 Elsevier Inc. All rights reserved.

Comparative utility of gated myocardial perfusion imaging and transthoracic coronary flow reserve for the assessment of coronary artery disease in patients with left bundle branch block.

PubMed

Pavlovic, Smiljana; Sobic-Saranovic, Dragana; Djordjevic-Dikic, Ana; Beleslin, Branko; Stepanovic, Jelena; Artiko, Vera; Giga, Vojislav; Petrasinovic, Zorica; Ostojic, Miodrag; Vujisic-Tesic, Bosiljka; Obradovic, Vladimir

2010-04-01

To compare the diagnostic utility of gated single-photon emission computed tomography (SPECT) methoxy isobutyl isonitrile (MIBI) myocardial perfusion imaging and transthoracic Doppler echocardiography (TTDE) coronary flow reserve (CFR) to coronary angiography for detecting coronary artery disease (CAD) in patients with left bundle branch block (LBBB). Forty-three patients with complete LBBB and an intermediate pretest probability for CAD underwent dipyridamole stress TTDE and gated SPECT MIBI during the same session and coronary angiography within a month. The parameters of myocardial perfusion (summed stress score, summed difference scores) regional wall function (wall motion score, wall thickening score) and ejection fraction were derived using the 17-segment model and 4D-MSPECT software. TTDE variables included peak flow velocity at rest and during hyperemia in left anterior descending artery (LAD), based on which CFR was calculated (normal>2). Perfusion ischemic scores were significantly higher in group 1 with angiographic evidence of greater than 50% LAD stenosis compared with group 2 with less than 50% LAD stenosis (summed stress score 12.4+/-5.5 vs. 8.3+/-3.5, P<0.05, summed difference score 3.7+/-1.2 vs. 1.1+/-0.3, P<0.01, respectively). Left ventricular regional wall function and ejection fraction were not different between the two groups. CFR was significantly lower in group 1 than in group 2 (1.65+/-0.21 vs. 2.31+/-0.28, P<0.001). Gated SPECT MIBI and CFR had similar sensitivity (88 vs. 88%), specificity (80 vs. 84%), and accuracy (84 vs. 86%) for detecting CAD in patients with LBBB. The agreement between the two methods was 85%. Our results show comparable diagnostic utility and high agreement between gated SPECT MIBI perfusion imaging and TTDE CFR assessment for detecting CAD in patients with LBBB. The advantage of gated SPECT MIBI over TTDE CFR measurements is the ability to assess the perfusion abnormalities in multiple vascular territories during the same procedure, which is convenient for detecting multi-vessel disease in patients with LBBB.

Management and Economic Implications of Bundling and Block Booking of Television and Cable Programming.

ERIC Educational Resources Information Center

Picard, Robert G.

Bundling, a practice which has increased dramatically in the television and cable industries in recent years, occurs when program distributors package groups of movies and episodes of series, and then sell licenses to use these packages to TV stations and cable channels. Typically, such bundled packages include both highly desirable and less…

A Simple Dissection Method for the Conduction System of the Human Heart

ERIC Educational Resources Information Center

Yanagawa, Nariaki; Nakajima, Yuji

2009-01-01

A simple dissection guide for the conduction system of the human heart is shown. The atrioventricular (AV) node, AV bundle, and right bundle branch were identified in a formaldehyde-fixed human heart. The sinu-atrial (SA) node could not be found, but the region in which SA node was contained was identified using the SA nodal artery. Gross…

The Fysics of Filopodia (or The Physics of Philopodia)

NASA Astrophysics Data System (ADS)

Schwarz, Jen; Gopinathan, Ajay; Lee, Kun-Chun; Liu, Andrea; Yang, Louise

2006-03-01

Cell motility is driven by the dynamic reorganization of the cellular cytoskeleton which is composed of actin. Monomeric actin assembles into filaments that grow, shrink, branch and bundle. Branching generates new filaments that form a mesh-like structure that protrudes outward allowing the cell to move somewhere. But how does it know where to move? It has been proposed that filopodia serve as scouts for the cell. Filopodia are bundles of actin filaments that extend out ahead of the rest of the cell to probe its upcoming environment. Recent in vitro experiments [Vignjevic et al., J. Ce ll Bio. 160, 951 (2003)] determine the minimal ingredients required for such a process. We model these experiments analytically and via Monte Carlo simulations to estimate the typical bundle size and length. We also estimate the size of the mesh-like structure from which the filopodia emerge and explain the observed nonmonotonicity of this size as a function of capping protein concentration, which inhibits filament growth.

[Chatergee syndrome and anesthesia. Apropos of a case].

PubMed

Le Marec, C; Belat, C; Caroff, P; Puidupin, M; Paris, A; Fourel, D; Dumas, P; Le Guern, G

1996-01-01

A combination of complete left bundle branch block (LBBB) and symmetrical negative T waves on the ECG characterizes the Chattergee syndrome. This pattern is infrequently and fortuitously detected in the absence of clinical symptoms. However, when appearing during general anaesthesia, it may lead to diagnostic difficulties to rule out a myocardial ischaemia. One case of this pattern was observed near the end of an otherwise non-complicated cholecystectomy in a ASA II 45 year old man, ECG abnormalities lasted for only a short time. Recovery and outcome were uneventful. Investigations were negative except for an early LBBB during the exercise test. Echocardiography and coronarography were normal. No therapy was given. In such perioperative cases, it is recommended to keep a very cautious attitude and to search for an incipient coronary disease which cannot be completely excluded in some cases.

Early history of the pre-excitation syndrome.

PubMed

Hanon, Sam; Shapiro, Michael; Schweitzer, Paul

2005-01-01

This brief review discusses the interesting early history of the pre-excitation syndrome. In 1913 Cohn and Fraser published the first patient with a short P-R interval, wide QRS complexes, and paroxysmal tachycardia. This was followed by other cases of pre-excitation syndrome, all of which were considered to be due to bundle branch blocks. In 1930 Wolff, Parkinson, and White reported 11 patients with the syndrome, which came to bear their name. Two years later, Holzmann and Scherf suggested bypass tracts as the most likely mechanism of pre-excitation syndrome. In 1942, Wood et al. documented the first accessory connection at autopsy. Despite these early studies supporting the bypass theory, the quest for alternative mechanisms continued until the 1970s when electrophysiological studies and surgical therapy confirmed accessory connections as the mechanism of pre-excitation syndrome.

The application of GPS precise point positioning technology in aerial triangulation

NASA Astrophysics Data System (ADS)

Yuan, Xiuxiao; Fu, Jianhong; Sun, Hongxing; Toth, Charles

In traditional GPS-supported aerotriangulation, differential GPS (DGPS) positioning technology is used to determine the 3-dimensional coordinates of the perspective centers at exposure time with an accuracy of centimeter to decimeter level. This method can significantly reduce the number of ground control points (GCPs). However, the establishment of GPS reference stations for DGPS positioning is not only labor-intensive and costly, but also increases the implementation difficulty of aerial photography. This paper proposes aerial triangulation supported with GPS precise point positioning (PPP) as a way to avoid the use of the GPS reference stations and simplify the work of aerial photography. Firstly, we present the algorithm for GPS PPP in aerial triangulation applications. Secondly, the error law of the coordinate of perspective centers determined using GPS PPP is analyzed. Thirdly, based on GPS PPP and aerial triangulation software self-developed by the authors, four sets of actual aerial images taken from surveying and mapping projects, different in both terrain and photographic scale, are given as experimental models. The four sets of actual data were taken over a flat region at a scale of 1:2500, a mountainous region at a scale of 1:3000, a high mountainous region at a scale of 1:32000 and an upland region at a scale of 1:60000 respectively. In these experiments, the GPS PPP results were compared with results obtained through DGPS positioning and traditional bundle block adjustment. In this way, the empirical positioning accuracy of GPS PPP in aerial triangulation can be estimated. Finally, the results of bundle block adjustment with airborne GPS controls from GPS PPP are analyzed in detail. The empirical results show that GPS PPP applied in aerial triangulation has a systematic error of half-meter level and a stochastic error within a few decimeters. However, if a suitable adjustment solution is adopted, the systematic error can be eliminated in GPS-supported bundle block adjustment. When four full GCPs are emplaced in the corners of the adjustment block, then the systematic error is compensated using a set of independent unknown parameters for each strip, the final result of the bundle block adjustment with airborne GPS controls from PPP is the same as that of bundle block adjustment with airborne GPS controls from DGPS. Although the accuracy of the former is a little lower than that of traditional bundle block adjustment with dense GCPs, it can still satisfy the accuracy requirement of photogrammetric point determination for topographic mapping at many scales.

Electrophysiologic and histologic observations of chronic atrioventricular block induced by closed-chest catheter desiccation with radiofrequency energy.

PubMed

Huang, S K; Bharati, S; Lev, M; Marcus, F I

1987-07-01

Direct-current or laser energy has been used to induce atrioventricular (AV) block, but certain complications associated with this type of energy have been reported. We have previously documented that radiofrequency (RF) energy can effectively and safely induce acute AV block in closed-chest dogs during the 4-7 days of follow-up. This study was undertaken to determine if the ablation was permanent and to define the chronic pathology and site of AV block. Complete AV block was successfully achieved in four dogs immediately after ablation with a bipolar "standard" RF output (750 kHz) delivered between the tip electrode of a standard 7F USCI catheter and an external patch electrode on the left lateral chest wall. During 2 months of follow-up, three dogs had persistent complete AV block with a stable escape rhythm; the other had persistent 2:1 AV block. Repeat His bundle recordings were performed at 2 months prior to sacrifice of the dogs. Supra-His AV block was noted in two dogs; His bundle potential could not be recorded in another two. Histologically, the damaged area was well delineated. In all animals, the AV node and, in some dogs, part of the His bundle were completely replaced by granulation tissue and/or cartilage. There was fatty infiltration and also chronic inflammatory cells around the lesions. Neither perforation, hemorrhage nor vacuolation was seen in the adjacent area. Thrombus was not present. It is concluded that RF energy can effectively achieve chronic AV block and produce well-circumscribed pathological lesions.

[Successful use of an AED following anterior myocardial infarction].

PubMed

Harding, Ulf; Reifferscheid, Florian; von Olshausen, Klaus

2007-05-01

A participant of the annual Hamburg marathon collapses on the finish line. Medics at the scene find a conscious patient and prepare transport to the finish area medical center. During transport the patient becomes unconscious and pulseless. The medics immediately perform basic life support and cardiopulmonary resuscitation (CPR). An automated external defibrillator (AED) is attached and after analysis of the patient}s heart rhythm the patient is defibrillated twice. The ambulance service reach the scene with a delay. The emergency physician}s ECG shows ventricular fibrillation (VF) and two more defibrillations are delivered. Return of spontaneous circulation can be achieved. After stabilisation the patient is taken to hospital by ambulance. The ECG shows an anterior myocardial infarction and right bundle-branch block. The coronary angioplasty (PTCA) shows single-vessel disease with complete stenosis of the proximal part of the anterior interventricular branch. Revasucarisation is successful and a coronary stent is applied. The patient survives neurologically intact. This case report demonstrates the importance of readily available AED and specially trained medics. By immediately using the AED this patient was defibrillated before the ambulance service and emergency physician arrived at the scene. Spontaneous circulation was restored.

Bundle block adjustment of large-scale remote sensing data with Block-based Sparse Matrix Compression combined with Preconditioned Conjugate Gradient

NASA Astrophysics Data System (ADS)

Zheng, Maoteng; Zhang, Yongjun; Zhou, Shunping; Zhu, Junfeng; Xiong, Xiaodong

2016-07-01

In recent years, new platforms and sensors in photogrammetry, remote sensing and computer vision areas have become available, such as Unmanned Aircraft Vehicles (UAV), oblique camera systems, common digital cameras and even mobile phone cameras. Images collected by all these kinds of sensors could be used as remote sensing data sources. These sensors can obtain large-scale remote sensing data which consist of a great number of images. Bundle block adjustment of large-scale data with conventional algorithm is very time and space (memory) consuming due to the super large normal matrix arising from large-scale data. In this paper, an efficient Block-based Sparse Matrix Compression (BSMC) method combined with the Preconditioned Conjugate Gradient (PCG) algorithm is chosen to develop a stable and efficient bundle block adjustment system in order to deal with the large-scale remote sensing data. The main contribution of this work is the BSMC-based PCG algorithm which is more efficient in time and memory than the traditional algorithm without compromising the accuracy. Totally 8 datasets of real data are used to test our proposed method. Preliminary results have shown that the BSMC method can efficiently decrease the time and memory requirement of large-scale data.

HIS bundle electrogram in rheumatic mitral valve disease with special reference to Bachmann's bundle block in P mitrale.

PubMed

Lee, Y S; Lien, W P

1975-08-01

HBEs were recorded from either the right or left ventricle or simultaneously from both in 26 patients with chronic rheumatic mitral stenosis alone or in association with other mild valvular lesions during the diagnostic cardiac catheterization. Eleven of the patients had auricular fibrillation. Of the remaining 15 patients with sinus mechanism and P mitrale in the surface electrocardiogram, 12 were noted to have H potential preceded the termination of P wave and gave P2H interval of negative value- so-called "Bachmann's bundle block". Among these, double atrial activities (A and A' waves) could be identified on the HBE recorded from the left ventricular endocardial surface with catheter electrodes positioned at the subarotic region in 7 patients studied. Interatrial conduction time (P1A' interval) measured in these patients was prolonged in all and ranged from 47 to 82 with an average of 66 msec. Prolongation of intraatrial (or internodal) conduction time was noted in only one patient who also had first degree A-V block and prolonged A-H interval. There was no correlation of either P1P2 or P2H interval to the degree of left atrial enlargement. The P1P2 or P2H interval also had no correlation with hemodynamic parameters. In patients with auricular fibrillation, all impulses unable to conduct to the ventricle were blocked proximal to the His bundle and concealed conduction was not observed distal to it.

Muscle architecture of the elongated nose in the Asian elephant (Elephas maximus).

PubMed

Endo, H; Hayashi, Y; Komiya, T; Narushima, E; Sasaki, M

2001-05-01

The architecture of the M. caninus in the elongated nose was examined in the Asian elephant (Elephas maximus). The following complicated musculature of the M. caninus was observed in the proximal and distal regions of the nose: (1) Proximal region: In the superficial layer, the longitudinal bundles are confirmed in the dorsal part, and the obliquely-oriented ones in the ventral part. In the middle layer, some bundles run ventro-distally, while other ones represent longitudinally-oriented running. The deep layer consists of complicated architecture of many bundles. Some muscle bundles run medio-laterally, while the others extend proximo-distally in this space. (2) Distal region: In the dorsal part of the M. caninus, the bundles run at deep-superficial direction, while in the ventral part the bundles are longitudinally arranged. The bundles run at lateral direction near the septum of the nasal conduits. The N. facialis and N. infraorbitalis send many branches in the lateral area of the M. caninus in the trunk. This muscle architecture of multi-oriented bundles and well-developed innervation to them suggest that they enable the elongated nose to act as a refined manipulator in the Asian elephant.

Technique for CT Fluoroscopy-Guided Lumbar Medial Branch Blocks and Radiofrequency Ablation.

PubMed

Amrhein, Timothy J; Joshi, Anand B; Kranz, Peter G

2016-09-01

The purpose of this study is to describe the procedure for CT fluoroscopy-guided lumbar medial branch blocks and facet radiofrequency ablation. CT fluoroscopic guidance allows more-precise needle tip positioning and is an alternative method for performing medial branch blocks and facet radiofrequency ablation.

Transvenous pacemaker electrodes placed unintentionally in the left ventricle: three cases.

PubMed Central

Winner, S. J.; Boon, N. A.

1989-01-01

Three patients are described in whom pacemaker electrodes were unintentionally placed within the left ventricle, followed by considerable delay before the error was recognized. In two cases temporary pacemaker wires were inserted into the subclavian artery and passed along a retrograde course. One patient required urgent surgery for acute arterial obstruction on removal of the wire. In the third case, a permanent wire was inserted correctly into a vein but traversed the atrial septum, probably via a patent foramen ovale, to enter the left ventricle. Twelve lead electrocardiograms in all three patients showed paced complexes with right bundle branch block configuration. This appearance should raise suspicion that the pacemaker electrode might be in the left ventricle, in which case its position should be defined by chest radiographs (including a lateral view) and echocardiography. Images Figure 1 Figure 3 Figure 4 PMID:2780472

Hyperkalemia masked by pseudo-stemi infarct pattern and cardiac arrest.

PubMed

Peerbhai, Shareez; Masha, Luke; DaSilva-DeAbreu, Adrian; Dhoble, Abhijeet

2017-12-01

Hyperkalemia is a common electrolyte abnormality and has well-recognized early electrocardiographic manifestations including PR prolongation and symmetric T wave peaking. With severe increase in serum potassium, dysrhythmias and atrioventricular and bundle branch blocks can be seen on electrocardiogram. Although cardiac arrest is a worrisome consequence of untreated hyperkalemia, rarely does hyperkalemia electrocardiographically manifest as acute ischemia. We present a case of acute renal failure complicated by malignant hyperkalemia and eventual ventricular fibrillation cardiac arrest. Recognition of this disorder was delayed secondary to an initial ECG pattern suggesting an acute ST segment elevation myocardial infarction (STEMI). Emergent coronary angiography performed showed no evidence of coronary artery disease. Pseudo-STEMI patterns are rarely seen in association with acute hyperkalemia and are most commonly described with patient without acute cardiac symptomatology. This is the first such case presenting concurrently with cardiac arrest. A brief review of this rare pseudo-infarct pattern is also given.

[The complex origin of ventricular tachycardia after the total correction of tetralogy of Fallot].

PubMed

Ressia, L; Graffigna, A; Salerno-Uriarte, J A; Viganò, M

1993-09-01

Two patients underwent surgical treatment of ventricular tachycardia after repair of tetralogy of Fallot. Both patients had right bundle branch block, moderate pulmonary valve incompetence and right ventricular dilatation, and were refractory to electrophysiologically guided drug therapy. Both patients underwent intraoperative epicardial mapping, which located the arrhythmogenic focus on the right ventricular outflow tract, on the border of the previous ventriculotomy. In one patient removal of the previous scar and endocardial cryoablation was successful in ablating the arrhythmia. In the other, the same procedure was only temporarily effective. VT recurred and was subsequently identified at the superior border of the closed ventricular septal defect. It was ablated by means of transcatheter radiofrequency. While VT from foci located on the right ventricular free wall can be easily detected and ablated, septal origin of VT requires extensive preoperative and intraoperative electrophysiological evaluation and may necessitate combined surgical and transcatheter procedures.

Case report: an unstable wide QRS complexes tachycardia after ablation of a poster-septal accessory pathway: What is the mechanism?

PubMed

Wang, Huan; Che, Xiaoru

2018-03-01

Differentiation of wide QRS complex tachycardia required repeated electrophysiological stimuli and mapping. However, instability of tachycardia would increase the difficulty in differential diagnosis. In this paper, we reported a wide QRS tachycardia following ablation of an atrioventricular reentrant tachycardia participated by a poster-septal accessory pathway. Limited differentiation strategy was performed because the wide QRS tachycardia was self-limited and with unstable hemodynamics. We analyzed the mechanism of the wide QRS tachycardia by only 4 beats ventricular overpacing. On the basis of the last ventricular pacing, an atypical atrioventricular nodal reentrant tachycardia was confirmed. After slow-pathway modification, the wide QRS tachycardia was eliminated. It was an atypical atrial-ventricular node reentrant tachycardia with right bundle branch block. Reasonable analysis based on electrophysiological electrophysiologic knowledge was the basis of successful diagnosis and treatment.

RSR' pattern and the risk of mortality in men and women free of cardiovascular disease.

PubMed

O'Neal, Wesley T; Qureshi, Waqas; Li, Yabing; Soliman, Elsayed Z

2015-01-01

This study included 6,398 participants (mean age 55 ± 0.34 years; 54% female; 49% white; 22% black; 24% Mexican; 4.3% other) free of clinical cardiovascular disease (CVD) and major ECG abnormalities. Cox regression was used to examine the association between the RSR' (incomplete right bundle branch block (RBBB) or right ventricular conduction delay) pattern and CVD and all-cause mortalities. The RSR' pattern was not associated with an increased risk of CVD (HR=1.10; 95%CI=0.63, 1.91) mortality or all-cause (HR=0.95; 95%CI=0.66, 1.35) mortality. The results were similar when the RSR' pattern was further separated into incomplete RBBB and right ventricular conduction delay. In conclusion, the RSR' pattern is a benign finding in older adults free of clinical CVD. Copyright © 2015 Elsevier Inc. All rights reserved.

MISR Center Block Time Tool

Atmospheric Science Data Center

2013-04-01

  MISR Center Block Time Tool The misr_time tool calculates the block center times for MISR Level 1B2 files. This is ... version of the IDL package or by using the IDL Virtual Machine application. The IDL Virtual Machine is bundled with IDL and is ...

Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae.

PubMed

Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Astushi

2016-09-08

BACKGROUND Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). CASE REPORT A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient's heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient's condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. CONCLUSIONS This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular extension of the infection, which can lead to fatal heart block.

Agreement in electrocardiogram interpretation in patients with septic shock.

PubMed

Mehta, Sangeeta; Granton, John; Lapinsky, Stephen E; Newton, Gary; Bandayrel, Kristofer; Little, Anjuli; Siau, Chuin; Cook, Deborah J; Ayers, Dieter; Singer, Joel; Lee, Terry C; Walley, Keith R; Storms, Michelle; Cooper, Jamie; Holmes, Cheryl L; Hebert, Paul; Gordon, Anthony C; Presneill, Jeff; Russell, James A

2011-09-01

The reliability of electrocardiogram interpretation to diagnose myocardial ischemia in critically ill patients is unclear. In adults with septic shock, we assessed intra- and inter-rater agreement of electrocardiogram interpretation, and the effect of knowledge of troponin values on these interpretations. Prospective substudy of a randomized trial of vasopressin vs. norepinephrine in septic shock. Nine Canadian intensive care units. Adults with septic shock requiring at least 5 μg/min of norepinephrine for 6 hrs. Twelve-lead electrocardiograms were recorded before study drug, and 6 hrs, 2 days, and 4 days after study drug initiation. Two physician readers, blinded to patient data and group, independently interpreted electrocardiograms on three occasions (first two readings were blinded to patient data; third reading was unblinded to troponin). To calibrate and refine definitions, both readers initially reviewed 25 trial electrocardiograms representing normal to abnormal. Cohen's Kappa and the φ statistic were used to analyze intra- and inter-rater agreement. One hundred twenty-one patients (62.2 ± 16.5 yrs, Acute Physiology and Chronic Health Evaluation II 28.6 ± 7.7) had 373 electrocardiograms. Blinded to troponin, readers 1 and 2 interpreted 46.4% and 30.0% of electrocardiograms as normal, and 15.3% and 12.3% as ischemic, respectively. Intrarater agreement was moderate for overall ischemia (κ 0.54 and 0.58), moderate/good for "normal" (κ 0.69 and 0.55), fair to good for specific signs of ischemia (ST elevation, T inversion, and Q waves, reader 1 κ 0.40 to 0.69; reader 2 κ 0.56 to 0.70); and good/very good for atrial arrhythmias (κ 0.84 and 0.79) and bundle branch block (κ 0.88 and 0.79). Inter-rater agreement was fair for ischemia (κ 0.29), moderate for ST elevation (κ 0.48), T inversion (κ 0.52), and Q waves (κ 0.44), good for bundle branch block (κ 0.78), and very good for atrial arrhythmias (κ 0.83). Inter-rater agreement for ischemia improved from fair to moderate (κ 0.52, p = .028) when unblinded to troponin. In patients with septic shock, inter-rater agreement of electrocardiogram interpretation for myocardial ischemia was fair, and improved with troponin knowledge.

[Screening for asymptomatic left ventricular systolic dysfunction in high-risk patients. Preliminary experience with a program based on the use of ECG and natriuretic peptide].

PubMed

Tarantini, Luigi; Cioffi, Giovanni; Di Lenarda, Andrea; Valle, Roberto; Pulignano, Giovanni; Del Sindaco, Donatella; Frigo, Gianfranco; Soravia, Giorgio; Tessier, Renato; Catania, Giuseppe

2008-12-01

Patients with asymptomatic left ventricular systolic dysfunction (ALVSD) have an increased risk of heart failure (HF) and a worse life expectancy. Since valuable therapies may prevent such dismal evolution, screening programs for ALVSD have recently been advocated to detect as early as possible such ominous condition. Echocardiography represents the gold standard for the assessment of ALVSD but its indiscriminate use in screening programs is impractical. Clinical multivariate risk assessment associated with ECG and serum brain natriuretic peptide (BNP) may be a feasible strategy to screen ALVSD. We prospectively sought to investigate the feasibility and effectiveness of a screening program for ALVSD based on ECG and BNP used in a hierarchical sequence in patients at high risk for HF. Patients > or =55 years old with > or =2 risk factors for HF or > or =70 years old with > or =1 risk factor for HF entered the study performing sequentially ECG, BNP and echocardiographic evaluation. ALVSD was defined as a left ventricular ejection fraction < or =50%. Thirty-three of 122 enrolled patients (27%) had ALVSD. They were older, presented more frequently a history of chemotherapy exposure, had often bundle branch block and higher BNP levels. No patient without any major abnormalities (atrial fibrillation, left ventricular hypertrophy, STT alterations of ischemic/strain origin, pathologic Q wave, bundle branch block) on ECG (n=31, 24.4%) had ALVSD. Among the 91 patients with abnormal ECG, ALVSD was observed in 33 (36%). The area under the receiver operating characteristic curve to detect ALVSD by BNP was 0.86 (confidence interval 0.79-0.94, p<0.0001) and BNP values of > or =43 pg/ml showed a sensitivity and a specificity of 94% and 57%, respectively. The proposed screening program was able to identify 95% (31/33) of patients with ALVSD saving 53% of echocardiographic examinations with a substantial reduction of the costs to diagnose ALVSD. Our prospective investigation confirms that ECG and BNP may be useful in detecting ALVSD in high-risk patients. A cost-effective screening program based on such simple and low-cost diagnostic tests might be employed for the prevention of HF in primary and secondary prevention programs in high-risk patients.

The potential complications of open carpal tunnel release surgery to the ulnar neurovascular bundle and its branches: A cadaveric study.

PubMed

Boughton, O; Adds, P J; Jayasinghe, J A P

2010-07-01

This study investigated the ulnar artery and the ulnar nerve and its branches in the palm to assess how frequently they may be at risk of damage during open carpal tunnel release surgery. Twenty-one formalin-embalmed cadaveric hands were dissected, and the proximity of the ulnar neurovascular bundle to two different lines of incision, the 3rd and 4th interdigital web space axis and the ring finger axis, was assessed and compared. It was found that an incision in the latter (ring finger) axis put the ulnar artery at risk in 12 of 21 specimens, whereas an incision in the former axis (3rd/4th interdigital web space) put the ulnar artery at risk in only two specimens. In 15 hands at least one structure (the ulnar artery or a branch of the ulnar nerve) was at risk in the ring finger axis compared to only seven hands in the axis of the 3rd/4th interdigital web space. We conclude that the ulnar artery and branches of the ulnar nerve are at increased risk of damage with an incision in the axis of the ring finger. The importance of using a blunt dissection technique under direct vision during surgery to identify and preserve these structures and median nerve branches is emphasized. (c) 2010 Wiley-Liss, Inc.

Hexagonally Ordered Arrays of α-Helical Bundles Formed from Peptide-Dendron Hybrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barkley, Deborah A.; Rokhlenko, Yekaterina; Marine, Jeannette E.

Combining monodisperse building blocks that have distinct folding properties serves as a modular strategy for controlling structural complexity in hierarchically organized materials. We combine an α-helical bundle-forming peptide with self-assembling dendrons to better control the arrangement of functional groups within cylindrical nanostructures. Site-specific grafting of dendrons to amino acid residues on the exterior of the α-helical bundle yields monodisperse macromolecules with programmable folding and self-assembly properties. The resulting hybrid biomaterials form thermotropic columnar hexagonal mesophases in which the peptides adopt an α-helical conformation. Bundling of the α-helical peptides accompanies self-assembly of the peptide-dendron hybrids into cylindrical nanostructures. The bundle stoichiometrymore » in the mesophase agrees well with the size found in solution for α-helical bundles of peptides with a similar amino acid sequence.« less

Effect of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) on Conduction System Disease.

PubMed

Dewland, Thomas A; Soliman, Elsayed Z; Davis, Barry R; Magnani, Jared W; Yamal, Jose-Miguel; Piller, Linda B; Haywood, L Julian; Alonso, Alvaro; Albert, Christine M; Marcus, Gregory M

2016-08-01

Cardiac conduction abnormalities are associated with an increased risk for morbidity and mortality, and understanding factors that accelerate or delay conduction system disease could help to identify preventive and therapeutic strategies. Antifibrotic and anti-inflammatory properties of angiotensin-converting enzyme inhibitors and treatment for hyperlipidemia may reduce the risk for incident conduction system disease. To identify the effect of pharmacologic therapy randomization and clinical risk factors on the incidence of conduction system disease. This secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) investigation acquired data from 623 North American centers. A total of 21 004 ambulatory individuals 55 years or older with hypertension and at least 1 other cardiac risk factor were included in the analysis. Participants were randomly assigned to receive amlodipine besylate, lisinopril, or chlorthalidone. Individuals with elevated fasting low-density lipoprotein cholesterol levels were also randomized to pravastatin sodium vs usual care. An electrocardiogram (ECG) was obtained at study enrollment and every 2 years of follow-up. The development of incident first-degree atrioventricular block, left anterior fascicular block, incomplete left bundle branch block (LBBB), LBBB, incomplete right bundle branch block (RBBB), RBBB, or intraventricular conduction delay was assessed by serial ECGs. The 21 004 participants (11 758 men [56.0%]; 9246 women [44.0%]; mean [SD] age, 66.5 [7.3] years) underwent a mean (SD) follow-up of 5.0 (1.2) years. Among the 1114 participants who developed any conduction defect, 389 developed LBBB, 570 developed RBBB, and 155 developed intraventricular conduction delay. Compared with chlorthalidone, randomization to lisinopril was associated with a significant 19% reduction in conduction abnormalities (hazard ratio [HR], 0.81; 95% CI, 0.69-0.95; P = .01). Treatment with amlodipine, however, was not associated with a significant difference in conduction outcome events (HR, 0.94; 95% CI, 0.81-1.09; P = .42). Similarly, pravastatin treatment was not associated with a reduced adjusted risk for incident disease compared with usual hyperlipidemia treatment (HR, 1.13; 95% CI, 0.95-1.35; P = .18). Increased age (HR, 1.47; 95% CI, 1.34-1.63; P < .001), male sex (HR, 0.59; 95% CI, 0.50-0.73; P < .001), white race (HR, 0.59; 95% CI, 0.50-0.70; P < .001), diabetes (HR, 1.23; 95% CI, 1.07-1.42; P = .003), and left ventricular hypertrophy (HR, 3.20; 95% CI, 2.61-3.94; P < .001) were also independently associated with increased risk for conduction system disease. Incident conduction system disease is significantly reduced by lisinopril therapy and is independently associated with multiple clinical factors. Further studies are warranted to determine whether pharmacologic treatment affects conduction abnormality outcomes, including pacemaker implantation. clinicaltrials.gov Identifier: NCT00000542.

Nonsurgical reduction of the interventricular septum in patients with hypertrophic cardiomyopathy.

PubMed

Shamim, Waqar; Yousufuddin, Mohammed; Wang, Duolao; Henein, Michael; Seggewiss, Hubert; Flather, Marcus; Coats, Andrew J S; Sigwart, Ulrich

2002-10-24

In patients with hypertrophic cardiomyopathy and obstruction of the left ventricular outflow tract, nonsurgical reduction of the septum is a treatment option when medical therapy has failed. We investigated the long-term effects of nonsurgical reduction of the septum on functional capacity and electrocardiographic and echocardiographic characteristics. Sixty-four consecutive patients with hypertrophic cardiomyopathy and a mean (+/-SD) age of 48.5+/-17.2 years underwent nonsurgical reduction of the septum by injection of ethanol into the septal perforator branch of the left anterior descending coronary artery. These patients were assessed by exercise testing, electrocardiography, and resting and dobutamine (stress-induced) echocardiography after a mean period of 3.0+/-1.3 years. At follow-up, patients had significant improvements in New York Heart Association class, peak oxygen consumption (from 18.4+/-5.8 to 30.0+/-4.4 ml per kilogram of body weight per minute, P<0.001), and left ventricular outflow tract gradients (resting gradient, from 64+/-36 to 16+/-15 mm Hg; P<0.001; stress-induced gradient, from 132+/-34 to 45+/-19 mm Hg; P<0.001). Procedure-related complications included right bundle-branch block in all patients, complete heart block in 31 patients (48 percent), and significant increases in QRS and corrected QT intervals. Seventeen patients (27 percent) required permanent pacing. R-wave amplitude was significantly decreased (from 32+/-8 to 17+/-7 mV, P<0.001). The dimensions of the left ventricular cavity increased, and the interventricular septal thickness was reduced. Nonsurgical septal reduction leads to sustained improvements in both subjective and objective measures of exercise capacity in association with a persistent reduction in resting and stress-induced left ventricular outflow tract gradients. It is also associated with a high incidence of procedure-related complete heart block, however, often requiring permanent pacing. Copyright 2002 Massachusetts Medical Society

Diagnosis and treatment of posterior sacroiliac complex pain: a systematic review with comprehensive analysis of the published data.

PubMed

King, Wade; Ahmed, Shihab U; Baisden, Jamie; Patel, Nileshkumar; Kennedy, David J; Duszynski, Belinda; MacVicar, John

2015-02-01

To assess the evidence on the validity of sacral lateral branch blocks and the effectiveness of sacral lateral branch thermal radiofrequency neurotomy in managing sacroiliac complex pain. Systematic review with comprehensive analysis of all published data. Six reviewers searched the literature on sacral lateral branch interventions. Each assessed the methodologies of studies found and the quality of the evidence presented. The outcomes assessed were diagnostic validity and effectiveness of treatment for sacroiliac complex pain. The evidence found was appraised in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system of evaluating scientific evidence. The searches yielded two primary publications on sacral lateral branch blocks and 15 studies of the effectiveness of sacral lateral branch thermal radiofrequency neurotomy. One study showed multisite, multidepth sacral lateral branch blocks can anesthetize the posterior sacroiliac ligaments. Therapeutic studies show sacral lateral branch thermal radiofrequency neurotomy can relieve sacroiliac complex pain to some extent. The evidence of the validity of these blocks and the effectiveness of this treatment were rated as moderate in accordance with the GRADE system. The literature on sacral lateral branch interventions is sparse. One study demonstrates the face validity of multisite, multidepth sacral lateral branch blocks for diagnosis of posterior sacroiliac complex pain. Some evidence of moderate quality exists on therapeutic procedures, but it is insufficient to determine the indications and effectiveness of sacral lateral branch thermal radiofrequency neurotomy, and more research is required. Wiley Periodicals, Inc.

Three Dimensional Visualization of Human Cardiac Conduction Tissue in Whole Heart Specimens by High-Resolution Phase-Contrast CT Imaging Using Synchrotron Radiation.

PubMed

Shinohara, Gen; Morita, Kiyozo; Hoshino, Masato; Ko, Yoshihiro; Tsukube, Takuro; Kaneko, Yukihiro; Morishita, Hiroyuki; Oshima, Yoshihiro; Matsuhisa, Hironori; Iwaki, Ryuma; Takahashi, Masashi; Matsuyama, Takaaki; Hashimoto, Kazuhiro; Yagi, Naoto

2016-11-01

The feasibility of synchrotron radiation-based phase-contrast computed tomography (PCCT) for visualization of the atrioventricular (AV) conduction axis in human whole heart specimens was tested using four postmortem structurally normal newborn hearts obtained at autopsy. A PCCT imaging system at the beamline BL20B2 in a SPring-8 synchrotron radiation facility was used. The PCCT imaging of the conduction system was performed with "virtual" slicing of the three-dimensional reconstructed images. For histological verification, specimens were cut into planes similar to the PCCT images, then cut into 5-μm serial sections and stained with Masson's trichrome. In PCCT images of all four of the whole hearts of newborns, the AV conduction axis was distinguished as a low-density structure, which was serially traceable from the compact node to the penetrating bundle within the central fibrous body, and to the branching bundle into the left and right bundle branches. This was verified by histological serial sectioning. This is the first demonstration that visualization of the AV conduction axis within human whole heart specimens is feasible with PCCT. © The Author(s) 2016.

Composition of clusters and building blocks in amylopectins from maize mutants deficient in starch synthase III.

PubMed

Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

2013-12-18

Branches in amylopectin are distributed along the backbone. Units of the branches are building blocks (smaller) and clusters (larger) based on the distance between branches. In this study, composition of clusters and building blocks of amylopectins from dull1 maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were characterized and compared with the wild type. Clusters were produced from amylopectins by partial hydrolysis using α-amylase of Bacillus amyloliquefaciens and were subsequently treated with phosphorylase a and β-amylase to produce φ,β-limit dextrins. Clusters were further extensively hydrolyzed with the α-amylase to produce building blocks. Structures of clusters and building blocks were analyzed by diverse chromatographic techniques. The results showed that the dull1 mutation resulted in larger clusters with more singly branched building blocks. The average cluster contained ~5.4 blocks in dull1 mutants and ~4.2 blocks in the wild type. The results are compared with previous results from SSIII-deficient amo1 barley and suggest fundamental differences in the cluster structures.

Absence of Rapid Propagation through the Purkinje Network as a Potential Cause of Line Block in the Human Heart with Left Bundle Branch Block.

PubMed

Okada, Jun-Ichi; Washio, Takumi; Nakagawa, Machiko; Watanabe, Masahiro; Kadooka, Yoshimasa; Kariya, Taro; Yamashita, Hiroshi; Yamada, Yoko; Momomura, Shin-Ichi; Nagai, Ryozo; Hisada, Toshiaki; Sugiura, Seiryo

2018-01-01

Background: Cardiac resynchronization therapy is an effective device therapy for heart failure patients with conduction block. However, a problem with this invasive technique is the nearly 30% of non-responders. A number of studies have reported a functional line of block of cardiac excitation propagation in responders. However, this can only be detected using non-contact endocardial mapping. Further, although the line of block is considered a sign of responders to therapy, the mechanism remains unclear. Methods: Herein, we created two patient-specific heart models with conduction block and simulated the propagation of excitation based on a cellmodel of electrophysiology. In one model with a relatively narrow QRS width (176 ms), we modeled the Purkinje network using a thin endocardial layer with rapid conduction. To reproduce a wider QRS complex (200 ms) in the second model, we eliminated the Purkinje network, and we simulated the endocardial mapping by solving the inverse problem according to the actual mapping system. Results: We successfully observed the line of block using non-contact mapping in the model without the rapid propagation of excitation through the Purkinje network, although the excitation in the wall propagated smoothly. This model of slow conduction also reproduced the characteristic properties of the line of block, including dense isochronal lines and fractionated local electrocardiograms. Further, simulation of ventricular pacing from the lateral wall shifted the location of the line of block. By contrast, in the model with the Purkinje network, propagation of excitation in the endocardial map faithfully followed the actual propagation in the wall, without showing the line of block. Finally, switching the mode of propagation between the two models completely reversed these findings. Conclusions: Our simulation data suggest that the absence of rapid propagation of excitation through the Purkinje network is the major cause of the functional line of block recorded by non-contact endocardial mapping. The line of block can be used to identify responders as these patients loose rapid propagation through the Purkinje network.

Optimized mode-field adapter for low-loss fused fiber bundle signal and pump combiners

NASA Astrophysics Data System (ADS)

Koška, Pavel; Baravets, Yauhen; Peterka, Pavel; Písařík, Michael; Bohata, Jan

2015-03-01

In our contribution we report novel mode field adapter incorporated inside bundled tapered pump and signal combiner. Pump and signal combiners are crucial component of contemporary double clad high power fiber lasers. Proposed combiner allows simultaneous matching to single mode core on input and output. We used advanced optimization techniques to match the combiner to a single mode core simultaneously on input and output and to minimalize losses of the combiner signal branch. We designed two arrangements of combiners' mode field adapters. Our numerical simulations estimates losses in signal branches of optimized combiners of 0.23 dB for the first design and 0.16 dB for the second design for SMF-28 input fiber and SMF-28 matched output double clad fiber for the wavelength of 2000 nm. The splice losses of the actual combiner are expected to be even lower thanks to dopant diffusion during the splicing process.

Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae

PubMed Central

Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Atsushi

2016-01-01

Patient: Male, 74 Final Diagnosis: Infective endocarditis Symptoms: Apetite loss • fever Medication: — Clinical Procedure: Transesophageal echocardiography Specialty: Cardiology Objective: Rare co-existance of disease or pathology Background: Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). Case Report: A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient’s heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient’s condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. Conclusions: This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular extension of the infection, which can lead to fatal heart block. PMID:27604147

Second-Degree Interatrial Block in Hemodialysis Patients

PubMed Central

Enriquez, Andres; D'Amato, Anna; de Luna, Antoni Bayes; Baranchuk, Adrian

2015-01-01

Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB) has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB. PMID:25755895

The ability of multi-site, multi-depth sacral lateral branch blocks to anesthetize the sacroiliac joint complex.

PubMed

Dreyfuss, Paul; Henning, Troy; Malladi, Niriksha; Goldstein, Barry; Bogduk, Nikolai

2009-01-01

To determine the physiologic effectiveness of multi-site, multi-depth sacral lateral branch injections. Double-blind, randomized, placebo-controlled study. Outpatient pain management center. Twenty asymptomatic volunteers. The dorsal innervation to the sacroiliac joint (SIJ) is from the L5 dorsal ramus and the S1-3 lateral branches. Multi-site, multi-depth lateral branch blocks were developed to compensate for the complex regional anatomy that limited the effectiveness of single-site, single-depth lateral branch injections. Bilateral multi-site, multi-depth lateral branch green dye injections and subsequent dissection on two cadavers revealed a 91% accuracy with this technique. Session 1: 20 asymptomatic subjects had a 25-g spinal needle probe their interosseous (IO) and dorsal sacroiliac (DSI) ligaments. The inferior dorsal SIJ was entered and capsular distension with contrast medium was performed. Discomfort had to occur with each provocation maneuver and a contained arthrogram was necessary to continue in the study. Session 2: 1 week later; computer randomized, double-blind multi-site, multi-depth lateral branch blocks injections were performed. Ten subjects received active (bupivicaine 0.75%) and 10 subjects received sham (normal saline) multi-site, multi-depth lateral branch injections. Thirty minutes later, provocation testing was repeated with identical methodology used in session 1. Presence or absence of pain for ligamentous probing and SIJ capsular distension. Seventy percent of the active group had an insensate IO and DSI ligaments, and inferior dorsal SIJ vs 0-10% of the sham group. Twenty percent of the active vs 10% of the sham group did not feel repeat capsular distension. Six of seven subjects (86%) retained the ability to feel repeat capsular distension despite an insensate dorsal SIJ complex. Multi-site, multi-depth lateral branch blocks are physiologically effective at a rate of 70%. Multi-site, multi-depth lateral branch blocks do not effectively block the intra-articular portion of the SIJ. There is physiological evidence that the intra-articular portion of the SIJ is innervated from both ventral and dorsal sources. Comparative multi-site, multi-depth lateral branch blocks should be considered a potentially valuable tool to diagnose extra-articular SIJ pain and determine if lateral branch radiofrequency neurotomy may assist one with SIJ pain.

49 CFR 393.118 - What are the rules for securing dressed lumber or similar building products?

Code of Federal Regulations, 2010 CFR

2010-10-01

... Shifting and Falling Cargo Specific Securement Requirements by Commodity Type § 393.118 What are the rules... transported using no more than one tier. Bundles carried on one tier must be secured in accordance with the... one tier. Bundles carried in more than one tier must be either: (1) Blocked against lateral movement...

Learning electrocardiogram on YouTube: how useful is it?

PubMed

Akgun, Taylan; Karabay, Can Yucel; Kocabay, Gonenc; Kalayci, Arzu; Oduncu, Vecih; Guler, Ahmet; Pala, Selcuk; Kirma, Cevat

2014-01-01

YouTube has become a useful resource for knowledge and is widely used by medical students as an e-learning source. The purpose of this study was to assess the videos relating electrocardiogram (ECG) on YouTube. YouTube was searched on May 28, 2013 for the search terms "AF ecg" for atrial fibrillation, "AVNRT" for atrioventricular nodal reentrant tachycardia, "AVRT" for atrioventricular reentrant tachycardia, "AV block or heart block" for atrioventricular block, "LBBB, RBBB" for bundle branch block, "left anterior fascicular block or left posterior fascicular block" for fascicular blocks, "VT ecg" for ventricular tachycardia, "long QT" and "Brugada ecg". Non-English language, unrelated and non-educational videos were excluded. Remaining videos were assessed for usefulness, source and characteristics. Usefulness was assessed with using a checklist developed by the authors. One hundred nineteen videos were included in the analysis. Sources of the videos were as follows: individuals n=70, 58.8%, universities/hospitals n=10, 8.4% and medical organizations n=3, 2.5%, health ads n=10 8.4%, health websites n=26, 21.8%. Fifty-six (47.1%) videos were classified as very useful and 16 (13.4%) videos were misleading. 90% of the videos uploaded by universities/hospitals were grouped as very useful videos, the same ratio was 45% for the individual uploads. There were statistically significant differences in ECG diagnosis among the groups (for very useful, useful and misleading, p<0.001, 0.02 and 0.008, respectively). The ratio of the misleading information in ventricular tachycardia videos was found to be 42.9%. YouTube has a substantial amount of videos on ECG with a wide diversity from useful to misleading content. The lack of quality content relating to ECG on YouTube necessitates that videos should be selected with utmost care. © 2013 Elsevier Inc. All rights reserved.

Biomechanical characterization of double-bundle femoral press-fit fixation techniques.

PubMed

Ettinger, M; Haasper, C; Hankemeier, S; Hurschler, C; Breitmeier, D; Krettek, C; Jagodzinski, M

2011-03-01

Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. To date, no biomechanical data exist describing an implant-free double-bundle press-fit procedure. The purpose of this study was to characterize the biomechanical properties of three double-bundle press-fit fixations. In a controlled laboratory study, the patellar-, quadriceps- and hamstring tendons of 10 human cadavers (age: 49.2 ± 18.5 years) were used. An inside out press-fit fixation with a knot in the semitendinosus and gracilis tendons (SG) combined with an additional bone block, with two quadriceps tendon bone block grafts (QU) was compared with press-fit fixation of two bone patellar tendon bone block (PT) grafts in 30 porcine femora. Constructs were cyclically stretched and then loaded until failure. Maximum load to failure, stiffness and elongation during failure testing and cyclical loading were investigated. The maximum load to failure was 703 ± 136 N for SG fixation, 632 ± 130 N for QU and 656 ± 127 N for PT fixation. Stiffness of the constructs averaged 138 ± 26 N/mm for SG, 159 ± 74 N/mm for QU, and 154 ± 50 N/mm for PT fixation. Elongation during initial cyclical loading was 1.2 ± 1.4 mm for SG, 2.0 ± 1.4 mm for QU, and 1.0 ± 0.6 mm for PT (significantly larger for PT and QU between the first 5 cycles compared with cycles 15-20th, P < 0.01). All investigated double-bundle fixation techniques were equal in terms of maximum load to failure, stiffness, and elongation. Unlike with single-bundle press-fit fixation techniques that have been published, no difference was observed between pure tendon combined with an additional bone block and tendon bone grafts. All techniques exhibited larger elongation during initial cyclical loading. All three press-fit fixation techniques that were investigated exhibit comparable biomechanical properties. Preconditioning of the constructs is critical.

Roles of silica and lignin in horsetail (Equisetum hyemale), with special reference to mechanical properties

NASA Astrophysics Data System (ADS)

Yamanaka, Shigeru; Sato, Kanna; Ito, Fuyu; Komatsubara, Satoshi; Ohata, Hiroshi; Yoshino, Katsumi

2012-02-01

This research deals with detailed analyses of silica and lignin distribution in horsetail with special reference to mechanical strength. Scanning electron images of a cross-section of an internode showed silica deposited densely only around the outer epidermis. Detailed histochemical analyses of lignin showed no lignin deposition in the silica-rich outer internodes of horsetail, while a characteristic lignin deposition was noticed in the vascular bundle in inner side of internodes. To analyze the structure of horsetail from a mechanical viewpoint, we calculated the response of a model structure of horsetail to a mechanical force applied perpendicularly to the long axis by a finite element method. We found that silica distributed in the outer epidermis may play the major structural role, with lignin's role being limited ensuring that the vascular bundle keep waterproof. These results were in contrast to more modern tall trees like gymnosperms, for which lignin provides mechanical strength. Lignin has the advantage of sticking to cellulose, hemicellulose, and other materials. Such properties make it possible for plants containing lignin to branch. Branching of tree stems aids in competing for light and other atmospheric resources. This type of branching was impossible for ancient horsetails, which relied on the physical properties of silica. From the evolutional view points, over millennia in trees with high lignin content, true branching, and many chlorophyll-containing leaves developed.

QRS analysis using wavelet transformation for the prediction of response to cardiac resynchronization therapy: a prospective pilot study.

PubMed

Vassilikos, Vassilios P; Mantziari, Lilian; Dakos, Georgios; Kamperidis, Vasileios; Chouvarda, Ioanna; Chatzizisis, Yiannis S; Kalpidis, Panagiotis; Theofilogiannakos, Efstratios; Paraskevaidis, Stelios; Karvounis, Haralambos; Mochlas, Sotirios; Maglaveras, Nikolaos; Styliadis, Ioannis H

2014-01-01

Wider QRS and left bundle branch block morphology are related to response to cardiac resynchronization therapy (CRT). A novel time-frequency analysis of the QRS complex may provide additional information in predicting response to CRT. Signal-averaged electrocardiograms were prospectively recorded, before CRT, in orthogonal leads and QRS decomposition in three frequency bands was performed using the Morlet wavelet transformation. Thirty eight patients (age 65±10years, 31 males) were studied. CRT responders (n=28) had wider baseline QRS compared to non-responders and lower QRS energies in all frequency bands. The combination of QRS duration and mean energy in the high frequency band had the best predicting ability (AUC 0.833, 95%CI 0.705-0.962, p=0.002) followed by the maximum energy in the high frequency band (AUC 0.811, 95%CI 0.663-0.960, p=0.004). Wavelet transformation of the QRS complex is useful in predicting response to CRT. © 2013.

Concrete induced cardiac contusion.

PubMed Central

Curzen, N.; Brett, S.; Fox, K.

1997-01-01

A previously fit 22 year old man was struck in the chest by a concrete block dropped through the windscreen of his car while he was driving on the motorway. He suffered extensive chest wall trauma and lung contusion, which subsequently precipitated acute respiratory distress. On admission ECG showed right bundle branch block and left axis deviation. Three days later QRS duration was normal but there was anterior ST segment elevation and subsequent T wave change. There was a large rise in creatine kinase, and echocardiography revealed septal and apical hyokinesis as well as a mobile mass attached to the left side of the interventricular septum, which had the echogenic texture of myocardium. The patient had fixed perfusion defects in the areas of hypokinesis on thallium scanning but the coronary arteries were unobstructed at angiography. He was treated with warfarin in the short term and an angiotensin converting enzyme inhibitor in the longer term and has made an asymptomatic recovery. Outpatient echocardiography two months after the injury demonstrated some recovery in overall left ventricular systolic function and no evidence of the intracardiac mass. This case illustrates some of the typical features of non-fatal cardiac contusion associated with non-penetrating cardiac trauma, and was complicated by partial thickness avulsion of a strip of the myocardium in the interventricular septum. Images PMID:9391297

Morbidity of Chagas heart disease in the microregion of Rio Negro, Amazonian Brazil: a case-control study

PubMed Central

Coura, José Rodrigues; Viñas, Pedro Albajar; Brum-Soares, Lucia Maria; de Sousa, Andréa Silvestre; Xavier, Sérgio Salles

2013-01-01

A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals. PMID:24402153

Process for sensing defects on a smooth cylindrical interior surface in tubing

DOEpatents

Dutton, G. Wayne

1987-11-17

The cylindrical interior surface of small diameter metal tubing is optically inspected to determine surface roughness by passing a slightly divergent light beam to illuminate the entire interior surface of the tubing. Impingement of the input light beam components on any rough spots on the interior surface generates forward and backward scattered radiation components. The forward scattered components can be measured by blocking direct and specular radiation components exiting the tubing while allowing the forward scattered radiation to travel past the blocking location. Collecting optics are employed to converge the forward scattered radiation onto a photodetector generating a signal indicative of surface roughness. In the back scattered mode, back scattered radiation exiting the tubing through the entrance opening is reflected 90.degree. by a beam splitter towards collecting optics and a photodetector. Alternatively, back scattered radiation can be transmitted through a fiber optic bundle towards the collecting optics. The input light beam can be supplied through a white light fiber optic bundle mounted coaxial with the first bundle.

Process for sensing defects on a smooth cylindrical interior surface in tubing

DOEpatents

Dutton, G.W.

1987-11-17

The cylindrical interior surface of small diameter metal tubing is optically inspected to determine surface roughness by passing a slightly divergent light beam to illuminate the entire interior surface of the tubing. Impingement of the input light beam components on any rough spots on the interior surface generates forward and backward scattered radiation components. The forward scattered components can be measured by blocking direct and specular radiation components exiting the tubing while allowing the forward scattered radiation to travel past the blocking location. Collecting optics are employed to converge the forward scattered radiation onto a photodetector generating a signal indicative of surface roughness. In the back scattered mode, back scattered radiation exiting the tubing through the entrance opening is reflected 90[degree] by a beam splitter towards collecting optics and a photodetector. Alternatively, back scattered radiation can be transmitted through a fiber optic bundle towards the collecting optics. The input light beam can be supplied through a white light fiber optic bundle mounted coaxial with the first bundle. 6 figs.

Process and apparatus for sensing defects on a smooth cylindrical surface in tubing

DOEpatents

Dutton, G.W.

1985-08-05

The cylindrical interior surface of small diameter metal tubing is optically inspected to determine surface roughness by passing a slightly divergent light beam to illuminate the entire interior surface of the tubing. Impingement of the input light beam components on any rough spots on the interior surface generates forward and backward scattered radiation components. The forward scattered components can be measured by blocking direct and specular radiation components exiting the tubing while allowing the forward scattered radiation to travel past the blocking location. Collecting optics are employed to converge the forward scattered radiation onto a photodetector generating a signal indicative of surface roughness. In the back scattered mode, back scattered radiation exiting the tubing through the entrance opening is reflected 90/sup 0/ by a beam splitter towards collecting optics and a photodetector. Alternatively, back scattered radiation can be transmitted through a fiber optic bundle towards the collecting optics. The input light beam can be supplied through a white light fiber optic bundle mounted coaxial with the first bundle.

A simple numerical model for membrane oxygenation of an artificial lung machine

NASA Astrophysics Data System (ADS)

Subraveti, Sai Nikhil; Sai, P. S. T.; Viswanathan Pillai, Vinod Kumar; Patnaik, B. S. V.

2015-11-01

Optimal design of membrane oxygenators will have far reaching ramification in the development of artificial heart-lung systems. In the present CFD study, we simulate the gas exchange between the venous blood and air that passes through the hollow fiber membranes on a benchmark device. The gas exchange between the tube side fluid and the shell side venous liquid is modeled by solving mass, momentum conservation equations. The fiber bundle was modelled as a porous block with a bundle porosity of 0.6. The resistance offered by the fiber bundle was estimated by the standard Ergun correlation. The present numerical simulations are validated against available benchmark data. The effect of bundle porosity, bundle size, Reynolds number, non-Newtonian constitutive relation, upstream velocity distribution etc. on the pressure drop, oxygen saturation levels etc. are investigated. To emulate the features of gas transfer past the alveoli, the effect of pulsatility on the membrane oxygenation is also investigated.

Influence of fiber packing structure on permeability

NASA Technical Reports Server (NTRS)

Cai, Zhong; Berdichevsky, Alexander L.

1993-01-01

The study on the permeability of an aligned fiber bundle is the key building block in modeling the permeability of advanced woven and braided preforms. Available results on the permeability of fiber bundles in the literature show that a substantial difference exists between numerical and analytical calculations on idealized fiber packing structures, such as square and hexagonal packing, and experimental measurements on practical fiber bundles. The present study focuses on the variation of the permeability of a fiber bundle under practical process conditions. Fiber bundles are considered as containing openings and fiber clusters within the bundle. Numerical simulations on the influence of various openings on the permeability were conducted. Idealized packing structures are used, but with introduced openings distributed in different patterns. Both longitudinal and transverse flow are considered. The results show that openings within the fiber bundle have substantial effect on the permeability. In the longitudinal flow case, the openings become the dominant flow path. In the transverse flow case, the fiber clusters reduce the gap sizes among fibers. Therefore the permeability is greatly influenced by these openings and clusters, respectively. In addition to the porosity or fiber volume fraction, which is commonly used in the permeability expression, another fiber bundle status parameter, the ultimate fiber volume fraction, is introduced to capture the disturbance within a fiber bundle.

The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling.

PubMed

Dobson, Laura E; Musa, Tarique A; Uddin, Akhlaque; Fairbairn, Timothy A; Bebb, Owen J; Swoboda, Peter P; Haaf, Philip; Foley, James; Garg, Pankaj; Fent, Graham J; Malkin, Christopher J; Blackman, Daniel J; Plein, Sven; Greenwood, John P

2017-02-22

Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling. 48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking. In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m 2 , p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months. TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB, especially as TAVR is now being extended to a younger, lower risk population.

Risk Factors for Permanent Pacemaker after Implantation of Surgical or Percutaneous Self-Expanding Aortic Prostheses.

PubMed

Villa, Emmanuel; Clerici, Alberto; Messina, Antonio; Testa, Luca; Bedogni, Francesco; Moneta, Andrea; Donatelli, Francesco; Troise, Giovanni

2016-11-01

The use of transcatheter aortic valve implantation (TAVI) following the introduction of Nitinol autoexpandable devices has spread rapidly during recent years. In addition, cardiac surgery has been revolutionized due to the use of Nitinol-based sutureless prostheses for aortic valve replacement (AVR). During the same period, however, permanent pacemaker (PPM) implantation has emerged as a frequent complication. The study aim was to identify the risk factors of PPM following the implantation of a Nitinol self-expanding prosthesis (for AVR or TAVI). A study group was created between two institutions experienced in the use of nitinol devices, and a pool of 336 patients (56.6% CoreValve - Medtronic; 43.4% Perceval - Sorin) was available for a retrospective analysis. Pre-procedural clinical and electrocardiography (ECG) variables and postprocedural ECG variables were compared between the PPM group and control patients who had not received a PPM during their index hospitalization. A PPM was required in 12.8% of patients (TAVI 17.5% versus AVR 6.8%, p = 0.007). PPM patients had a higher logistical EuroSCORE (median 20.77% versus 15.59%, p = 0.015), a lower use of statins (18.6% versus 34.2%, p = 0.04), a pre-procedural longer QRS interval (median 117 ms versus 98 ms, p = 0.002), and a higher incidence of conduction disturbances (29.3% versus 16.8%, p = 0.034), with a prevalence of right bundle branch block. At the first postprocedural ECG, non-stimulated PPM patients had a longer QRS interval (median 150 ms versus 113 ms, p<0.001) and a longer QTc interval (487.3 ± 46 ms versus 510.8 ± 53.8 ms, p = 0.005). Prevalent intra-ventricular conduction disorders in both groups included left bundle branch block. AVR patients received a PPM later than the TAVI group (median 6 days versus 3 days, p = 0.01). TAVI was an independent predictor of PPM at logistic regression analysis (OR 3.18; 95% CI 1.19-8.48, p = 0.021), but the significance disappeared after incorporating post-procedural ECG variables. Nitinol technology is a ground-breaking option for aortic valve procedures. However, the radial forces of the self-expandable mechanism may be implicated in the increased need for PPM, mostly in cases of TAVI compared to AVR, that most likely are due to displacement of the stent provoked by in situ calcium clusters. Given the clinical and economic impact of PPM, new parameters are required to understand the stent/tissue interaction and to help with device selection.

[Organic and functional limitations due to milking phenomenon: a clinical case report].

PubMed

Gómez-Henry, Juan Carlos; Rodríguez-Pérez, Francisco Antonio

2014-01-01

The incidence of milking phenomenon is between 0.6 and 4 % in angiographic series; however, autopsy studies raise the incidence of myocardial bridges up to 85 %. This malformation goes unnoticed in most cases but can have a big impact on personal and professional level. The objective was to present an example of milking phenomenon with disability and professional consequences. Male, 44 years old, bricklayer and farmhand laborer. He referred tonsillectomy and osteoarthritis and being a smoker of 10 cigarettes per day, drinking 2-3 cups of coffee daily and 2-3 glasses of wine at the weekends. The primary care physician referred him to cardiologist with suspicion of arrhythmia. The cardiology service report mentioned electrocardiogram at sinusal rhythm, 90 beats per minute and incomplete right bundle-branch block. At ergonomics test, in the first stage of Bruce protocol, the patient's development of hypertensive crisis suggested a milking phenomenon. Finally, the diagnosis was established by angiographic studies with left common branch, circumflex coronary artery, right coronary artery and anterior descendent artery, without evidence of pathology but it was seen systolic compression on the medial segment. The case was concluded by the disability assessment team, recognizing a total permanent disability with limitations for activities requiring moderate physical efforts. The milking phenomenon diagnosis that could be related with ischemic heart disease is by angiography. Finally, the patient ended with total permanent disability.

Hierarchical self-assembly of di-, tri- and tetraphenylalanine peptides capped with two fluorenyl functionalities: from polymorphs to dendrites.

PubMed

Mayans, Enric; Ballano, Gema; Casanovas, Jordi; Del Valle, Luis J; Pérez-Madrigal, Maria M; Estrany, Francesc; Jiménez, Ana I; Puiggalí, Jordi; Cativiela, Carlos; Alemán, Carlos

2016-06-28

Homopeptides with 2, 3 and 4 phenylalanine (Phe) residues and capped with fluorenylmethoxycarbonyl and fluorenylmethyl esters at the N-terminus and C-terminus, respectively, have been synthesized to examine their self-assembly capabilities. Depending on the conditions, the di- and triphenylalanine derivatives self-organize into a wide variety of stable polymorphic structures, which have been characterized: stacked braids, doughnut-like shapes, bundled arrays of nanotubes, corkscrew-like shapes and spherulitic microstructures. These highly aromatic Phe-based peptides also form incipient branched dendritic microstructures, even though they are highly unstable, making their manipulation very difficult. Conversely, the tetraphenylalanine derivative spontaneously self-assembles into stable dendritic microarchitectures made of branches growing from nucleated primary frameworks. The fractal dimension of these microstructures is ∼1.70, which provides evidence for self-similarity and two-dimensional diffusion controlled growth. DFT calculations at the M06L/6-31G(d) level have been carried out on model β-sheets since this is the most elementary building block of Phe-based peptide polymorphs. The results indicate that the antiparallel β-sheet is more stable than the parallel one, with the difference between them growing with the number of Phe residues. Thus, the cooperative effects associated with the antiparallel disposition become more favorable when the number of Phe residues increases from 2 to 4, while those of the parallel disposition remained practically constant.

Electrophysiological evidence of doubly innervated branched muscle fibers in the human brachioradialis muscle.

PubMed

Lateva, Zoia C; McGill, Kevin C

2007-12-01

Motor-unit action potentials (MUAPs) with unstable satellite (late-latency) components are found in EMG signals from the brachioradialis muscles of normal subjects. We analyzed the morphology and blocking behavior of these MUAPs to determine their anatomical origin. EMG signals were recorded from the brachioradialis muscles of 5 normal subjects during moderate-level isometric contractions. MUAP waveforms, discharge patterns, and blocking were determined using computer-aided EMG decomposition. Twelve MUAPs with unstable satellite potentials were detected, always two together in the same signal. Each MUAP also had a second unstable component associated with its main spike. The blocking behavior of the unstable components depended on how close together the two MUAPs were when they discharged. The latencies and blocking behavior indicate that the unstable components came from branched muscle fibers innervated by two different motoneurons. The satellite potentials were due to action potentials that traveled to the branching point along one branch and back along the other. The blockings were due to action-potential collisions when both motoneurons discharged close together in time. Animal studies suggest that branched muscle fibers may be a normal characteristic of series-fibered muscles. This study adds to our understanding of these muscles in humans.

"To Whom It May Concern": A Study on the Use of Lexical Bundles in Email Writing Tasks in an English Proficiency Test

ERIC Educational Resources Information Center

Li, Zhi; Volkov, Alex

2017-01-01

Lexical bundles are worthy of attention in both teaching and testing writing as they function as basic building blocks of discourse. This corpus-based study focuses on the rated writing responses to the email tasks in the Canadian English Language Proficiency Index Program® General test (CELPIP-General) and explores the extent to which lexical…

Synthetic peptides that cause F-actin bundling and block actin depolymerization

DOEpatents

Sederoff, Heike [Raleigh, NC; Huber, Steven C [Savoy, IL; Larabell, Carolyn A [Berkeley, CA

2011-10-18

Synthetic peptides derived from sucrose synthase, and having homology to actin and actin-related proteins, sharing a common motif, useful for causing acting bundling and preventing actin depolymerization. Peptides exhibiting the common motif are described, as well as specific synthetic peptides which caused bundled actin and inhibit actin depolymerization. These peptides can be useful for treating a subject suffering from a disease characterized by cells having neoplastic growth, for anti-cancer therapeutics, delivered to subjects solely, or concomitantly or sequentially with other known cancer therapeutics. These peptides can also be used for stabilizing microfilaments in living cells and inhibiting growth of cells.

Positional relationships between the masticatory muscles and their innervating nerves with special reference to the lateral pterygoid and the midmedial and discotemporal muscle bundles of temporalis

PubMed Central

AKITA, KEIICHI; SHIMOKAWA, TAKASHI; SATO, TATSUO

2000-01-01

For an accurate assessment of jaw movement, it is crucial to understand the comprehensive formation of the masticatory muscles with special reference to the relationship to the disc of the temporomandibular joint. Detailed dissection was performed on 26 head halves of 14 Japanese cadavers in order to obtain precise anatomical information of the positional relationships between the masticatory muscles and the branches of the mandibular nerve. After complete removal of the bony elements, the midmedial muscle bundle in all specimens and the discotemporal muscle bundle in 6 specimens, derivatives of the temporalis, which insert into the disc were observed. On the anterior area of the articular capsule and the disc of the temporomandibular joint, the upper head of the lateral pterygoid, the midmedial muscle bundle of temporalis and the discotemporal bundle of temporalis were attached mediolaterally, and in 3 specimens the posterosuperior margin of the zygomaticomandibularis was attached to the anterolateral area of the disc. It is suggested that these muscles and muscle bundles contribute to various mandibular movements. Although various patterns of the positional relationships between the muscles and muscle bundles and the their innervating nerves are observed in the present study, relative positional relationships of the muscles and muscle bundles and of nerves of the mandibular nerve are consistent. A possible scheme of the developmental formation of the masticatory muscles based on the findings of the positional relationships between the muscles and the nerves is presented. PMID:11005720

Macroscopic Innervation of the Dura Mater Covering the Middle Cranial Fossa in Humans Correlated to Neurovascular Headache

PubMed Central

Lee, Shin-Hyo; Hwang, Seung-Jun; Koh, Ki-Seok; Song, Wu-Chul; Han, Sang-Don

2017-01-01

The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA) in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler’s method. Overall, the nervus spinosus (NS) from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases (N = 36). Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%). The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%). These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion. PMID:29311855

Macroscopic Innervation of the Dura Mater Covering the Middle Cranial Fossa in Humans Correlated to Neurovascular Headache.

PubMed

Lee, Shin-Hyo; Hwang, Seung-Jun; Koh, Ki-Seok; Song, Wu-Chul; Han, Sang-Don

2017-01-01

The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA) in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler's method. Overall, the nervus spinosus (NS) from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases ( N = 36). Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%). The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%). These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion.

Recognition of the epicardial breakthrough on body surface isopotential maps: influence of the inter-electrode distance on the patterns reflecting the epicardial breakthrough.

PubMed

Toyama, J; Tabata, O

1981-10-01

The epicardial breakthrough can be recognized from the localized depression of the body surface potential, which is characterized by a localized bend of the equipotential lines or a send-minimum on isopotential maps. Recognition of epicardial breakthrough with isopotential maps enables us to diagnose location of the block site of the bundle branch blocks more precisely than by ECG or VCG. However, the optimum inter-electrode distance for detection of such a localized potential has not been determined. In the present study, influence of the inter-electrode distance on the characteristic patterns reflecting the epicardial breakthrough was studied on 16 healthy persons using 9 x 9 electrode arrays with inter-electrode distance of 1.25 cm, 5 x 5 with 2.5 cm, and 3 x 3 with 5 cm. Breakthrough was recognized in 15 out of 16 cases (94%) on maps recorded with electrode arrays with inter-electrode distance of 1.25 and 2.5 cm. However, detectability of the breakthrough was reduced to 10 out of 16 cases (63%) with electrode array having inter-electrode distance of 5 cm. In conclusion, it is preferable to use an electrode array with an inter-electrode distance of no more than 2.5 cm for the purpose of breakthrough recognition.

Transcription factor ETV1 is essential for rapid conduction in the heart.

PubMed

Shekhar, Akshay; Lin, Xianming; Liu, Fang-Yu; Zhang, Jie; Mo, Huan; Bastarache, Lisa; Denny, Joshua C; Cox, Nancy J; Delmar, Mario; Roden, Dan M; Fishman, Glenn I; Park, David S

2016-12-01

Rapid impulse propagation in the heart is a defining property of pectinated atrial myocardium (PAM) and the ventricular conduction system (VCS) and is essential for maintaining normal cardiac rhythm and optimal cardiac output. Conduction defects in these tissues produce a disproportionate burden of arrhythmic disease and are major predictors of mortality in heart failure patients. Despite the clinical importance, little is known about the gene regulatory network that dictates the fast conduction phenotype. Here, we have used signal transduction and transcriptional profiling screens to identify a genetic pathway that converges on the NRG1-responsive transcription factor ETV1 as a critical regulator of fast conduction physiology for PAM and VCS cardiomyocytes. Etv1 was highly expressed in murine PAM and VCS cardiomyocytes, where it regulates expression of Nkx2-5, Gja5, and Scn5a, key cardiac genes required for rapid conduction. Mice deficient in Etv1 exhibited marked cardiac conduction defects coupled with developmental abnormalities of the VCS. Loss of Etv1 resulted in a complete disruption of the normal sodium current heterogeneity that exists between atrial, VCS, and ventricular myocytes. Lastly, a phenome-wide association study identified a link between ETV1 and bundle branch block and heart block in humans. Together, these results identify ETV1 as a critical factor in determining fast conduction physiology in the heart.

Transcription factor ETV1 is essential for rapid conduction in the heart

PubMed Central

Shekhar, Akshay; Lin, Xianming; Liu, Fang-Yu; Zhang, Jie; Mo, Huan; Bastarache, Lisa; Denny, Joshua C.; Cox, Nancy J.; Delmar, Mario; Roden, Dan M.; Fishman, Glenn I.; Park, David S.

2016-01-01

Rapid impulse propagation in the heart is a defining property of pectinated atrial myocardium (PAM) and the ventricular conduction system (VCS) and is essential for maintaining normal cardiac rhythm and optimal cardiac output. Conduction defects in these tissues produce a disproportionate burden of arrhythmic disease and are major predictors of mortality in heart failure patients. Despite the clinical importance, little is known about the gene regulatory network that dictates the fast conduction phenotype. Here, we have used signal transduction and transcriptional profiling screens to identify a genetic pathway that converges on the NRG1-responsive transcription factor ETV1 as a critical regulator of fast conduction physiology for PAM and VCS cardiomyocytes. Etv1 was highly expressed in murine PAM and VCS cardiomyocytes, where it regulates expression of Nkx2-5, Gja5, and Scn5a, key cardiac genes required for rapid conduction. Mice deficient in Etv1 exhibited marked cardiac conduction defects coupled with developmental abnormalities of the VCS. Loss of Etv1 resulted in a complete disruption of the normal sodium current heterogeneity that exists between atrial, VCS, and ventricular myocytes. Lastly, a phenome-wide association study identified a link between ETV1 and bundle branch block and heart block in humans. Together, these results identify ETV1 as a critical factor in determining fast conduction physiology in the heart. PMID:27775552

Mode-field adapter for tapered-fiber-bundle signal and pump combiners.

PubMed

Koška, Pavel; Baravets, Yauhen; Peterka, Pavel; Bohata, Jan; Písařík, Michael

2015-02-01

We report on a novel mode-field adapter that is proposed to be incorporated inside tapered fused-fiber-bundle pump and signal combiners for high-power double-clad fiber lasers. Such an adapter allows optimization of signal-mode-field matching on the input and output fibers. Correspondingly, losses of the combiner signal branch are significantly reduced. The mode-field adapter optimization procedure is demonstrated on a combiner based on commercially available fibers. Signal wavelengths of 1.55 and 2 μm are considered. The losses can be further improved by using specially designed intermediate fiber and by dopant diffusion during splicing as confirmed by preliminary experimental results.

Differential Effects of RET and TRKB on Axonal Branching and Survival of Parasympathetic Neurons

PubMed Central

Simpson, Julie; Keefe, Julie; Nishi, Rae

2014-01-01

Interactions between neurons and their targets of innervation influence many aspects of neural development. To examine how synaptic activity interacts with neurotrophic signaling, we determined the effects of blocking neuromuscular transmission on survival and axonal outgrowth of ciliary neurons from the embryonic chicken ciliary ganglion. Ciliary neurons undergo a period of cell loss due to programmed cell death between embryonic Days (E) 8 and 14 and they innervate the striated muscle of the iris. The nicotinic antagonist d-tubocurarine (dTC) induces an increase in branching measured by counting neurofilament-positive voxels (NF-VU) in the iris between E14–17 while reducing ciliary neuron survival. Blocking ganglionic transmission with dihyro-β-erythroidin and α-methyllycacontine does not mimic dTC. At E8, many trophic factors stimulate neurite outgrowth and branching of neurons placed in cell culture; however, at E13, only GDNF stimulates branching selectively in cultured ciliary neurons. The GDNF-induced branching at E13 could be inhibited by BDNF. Blocking ret signaling in vivo with a dominant negative (dn)ret decreases survival of ciliary and choroid neurons at E14 and prevents dTC induced increases in NF-VU in the iris at E17. Blocking TRKB signaling with dn TRKB increases NF-VU in the iris at E17 and decreases neuronal survival at E17, but not at E14. Thus, RET promotes survival during programmed cell death in the ciliary ganglion and contributes to promoting branching when synaptic transmission is blocked while TRKB inhibits branching and promotes maintenance of neuronal survival. These studies highlight the multifunctional nature of trophic molecule function during neuronal development. PMID:22648743

His bundle electrography

MedlinePlus

... a part of the heart that carries the signals that control the time between heartbeats (contractions). ... through the center of the heart. If these signals are blocked, you will have problems with your ...

Determination of Phobos' rotational parameters by an inertial frame bundle block adjustment

NASA Astrophysics Data System (ADS)

Burmeister, Steffi; Willner, Konrad; Schmidt, Valentina; Oberst, Jürgen

2018-01-01

A functional model for a bundle block adjustment in the inertial reference frame was developed, implemented and tested. This approach enables the determination of rotation parameters of planetary bodies on the basis of photogrammetric observations. Tests with a self-consistent synthetic data set showed that the implementation converges reliably toward the expected values of the introduced unknown parameters of the adjustment, e.g., spin pole orientation, and that it can cope with typical observational errors in the data. We applied the model to a data set of Phobos using images from the Mars Express and the Viking mission. With Phobos being in a locked rotation, we computed a forced libration amplitude of 1.14^circ ± 0.03^circ together with a control point network of 685 points.

Blocking performance approximation in flexi-grid networks

NASA Astrophysics Data System (ADS)

Ge, Fei; Tan, Liansheng

2016-12-01

The blocking probability to the path requests is an important issue in flexible bandwidth optical communications. In this paper, we propose a blocking probability approximation method of path requests in flexi-grid networks. It models the bundled neighboring carrier allocation with a group of birth-death processes and provides a theoretical analysis to the blocking probability under variable bandwidth traffic. The numerical results show the effect of traffic parameters to the blocking probability of path requests. We use the first fit algorithm in network nodes to allocate neighboring carriers to path requests in simulations, and verify approximation results.

The Actions of Calcium on Hair Bundle Mechanics in Mammalian Cochlear Hair Cells

PubMed Central

Beurg, Maryline; Nam, Jong-Hoon; Crawford, Andrew; Fettiplace, Robert

2008-01-01

Sound stimuli excite cochlear hair cells by vibration of each hair bundle, which opens mechanotransducer (MT) channels. We have measured hair-bundle mechanics in isolated rat cochleas by stimulation with flexible glass fibers and simultaneous recording of the MT current. Both inner and outer hair-cell bundles exhibited force-displacement relationships with a nonlinearity that reflects a time-dependent reduction in stiffness. The nonlinearity was abolished, and hair-bundle stiffness increased, by maneuvers that diminished calcium influx through the MT channels: lowering extracellular calcium, blocking the MT current with dihydrostreptomycin, or depolarizing to positive potentials. To simulate the effects of Ca2+, we constructed a finite-element model of the outer hair cell bundle that incorporates the gating-spring hypothesis for MT channel activation. Four calcium ions were assumed to bind to the MT channel, making it harder to open, and, in addition, Ca2+ was posited to cause either a channel release or a decrease in the gating-spring stiffness. Both mechanisms produced Ca2+ effects on adaptation and bundle mechanics comparable to those measured experimentally. We suggest that fast adaptation and force generation by the hair bundle may stem from the action of Ca2+ on the channel complex and do not necessarily require the direct involvement of a myosin motor. The significance of these results for cochlear transduction and amplification are discussed. PMID:18178649

Spontaneous Oscillation by Hair Bundles of the Bullfrog's Sacculus

PubMed Central

Martin, Pascal; Bozovic, D.; Choe, Y.; Hudspeth, A. J.

2007-01-01

One prominent manifestation of mechanical activity in hair cells is spontaneous otoacoustic emission, the unprovoked emanation of sound by an internal ear. Because active hair-bundle motility probably constitutes the active process of non-mammalian hair cells, we investigated the ability of hair bundles in the bullfrog's sacculus to produce oscillations that might underlie spontaneous otoacoustic emissions. When maintained in the ear's normal ionic milieu, many bundles oscillated spontaneously through distances as great as 80 nm at frequencies of 5-50 Hz. Whole-cell recording disclosed that the positive phase of movement was associated with the opening of transduction channels. Gentamicin, which blocks transduction channels, reversibly arrested oscillation; drugs that affect the cAMP phosphorylation pathway and might influence myosin's activity altered the rate of oscillation. Increasing the Ca2+ concentration rendered oscillations faster and smaller until they were suppressed; lowering the Ca2+ concentration moderately with chelators had the opposite effect. When a bundle was offset with a stimulus fiber, oscillations were transiently suppressed but gradually resumed. Loading a bundle by partial displacement clamping, which simulated the presence of the accessory structures to which a bundle is ordinarily attached, increased the frequency and diminished the magnitude of oscillation. These observations accord with a model in which oscillations arise from the interplay of the hair bundle's negative stiffness with the activity of adaptation motors and with Ca2+-dependent relaxation of gating springs. PMID:12805294

Harmony of spinning conformal blocks

NASA Astrophysics Data System (ADS)

Schomerus, Volker; Sobko, Evgeny; Isachenkov, Mikhail

2017-03-01

Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

Automated detection of heart ailments from 12-lead ECG using complex wavelet sub-band bi-spectrum features.

PubMed

Tripathy, Rajesh Kumar; Dandapat, Samarendra

2017-04-01

The complex wavelet sub-band bi-spectrum (CWSB) features are proposed for detection and classification of myocardial infarction (MI), heart muscle disease (HMD) and bundle branch block (BBB) from 12-lead ECG. The dual tree CW transform of 12-lead ECG produces CW coefficients at different sub-bands. The higher-order CW analysis is used for evaluation of CWSB. The mean of the absolute value of CWSB, and the number of negative phase angle and the number of positive phase angle features from the phase of CWSB of 12-lead ECG are evaluated. Extreme learning machine and support vector machine (SVM) classifiers are used to evaluate the performance of CWSB features. Experimental results show that the proposed CWSB features of 12-lead ECG and the SVM classifier are successful for classification of various heart pathologies. The individual accuracy values for MI, HMD and BBB classes are obtained as 98.37, 97.39 and 96.40%, respectively, using SVM classifier and radial basis function kernel function. A comparison has also been made with existing 12-lead ECG-based cardiac disease detection techniques.

Brugada syndrome: two decades of progress.

PubMed

Veerakul, Gumpanart; Nademanee, Koonlawee

2012-01-01

Two decades ago, a series of 8 idiopathic ventricular fibrillation patients who each had an abnormal ECG (right bundle branch block with coved-type ECG), but otherwise had normal hearts were described by Brugada and Brugada. Since then, the clinical entity has become known as Brugada syndrome (BS). Shortly thereafter, mutations of the SCN5A gene that encodes for the α-subunit of the sodium channel were found, galvanizing the field of ion channelopathies following in the footsteps of the breakthrough in long QT syndrome. Over the past 20 years, extensive research in this field has produced major progress toward better understanding of BS and the gaining of knowledge of the genetic background, pathophysiology and new management. Two consensus reports were published to help define the diagnostic criteria, risk stratification and management of BS patients. However, there are controversies. In this review, we will share our experiences of BS patients in Thailand and discuss advances in many aspects of the syndrome (ie, genetics and pathophysiology) and some of these pertinent controversies, as well as new treatment of the syndrome with catheter ablation.

Electrocardiographic features of sudden unexpected death in epilepsy.

PubMed

Chyou, Janice Y; Friedman, Daniel; Cerrone, Marina; Slater, William; Guo, Yu; Taupin, Daniel; O'Rourke, Sean; Priori, Silvia G; Devinsky, Orrin

2016-07-01

Sudden unexpected death in epilepsy (SUDEP) is the most common cause of epilepsy-related mortality. We hypothesized that electrocardiography (ECG) features may distinguish SUDEP cases from living subjects with epilepsy. Using a matched case-control design, we compared ECG studies of 12 consecutive cases of SUDEP over 10 years and 22 epilepsy controls matched for age, sex, epilepsy type (focal, generalized, or unknown/mixed type), concomitant antiepileptic, and psychotropic drug classes. Conduction intervals and prevalence of abnormal ventricular conduction diagnosis (QRS ≥110 msec), abnormal ventricular conduction pattern (QRS <110 msec, morphology of incomplete right or left bundle branch block or intraventricular conduction delay), early repolarization, and features of inherited cardiac channelopathies were assessed. Abnormal ventricular conduction diagnosis and pattern distinguished SUDEP cases from matched controls. Abnormal ventricular conduction diagnosis was present in two cases and no controls. Abnormal ventricular conduction pattern was more common in cases than controls (58% vs. 18%, p = 0.04). Early repolarization was similarly prevalent in cases and controls, but the overall prevalence exceeded that of published community-based cohorts. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

The initial electrocardiogram during admission for myocardial infarction. Use as a predictor of clinical course and facility utilization.

PubMed

Stark, M E; Vacek, J L

1987-05-01

The first electrocardiogram obtained on presentation for suspected myocardial infarction was examined for its usefulness in predicting clinical course and facility use. We studied 221 patients consecutively admitted to a nonuniversity hospital coronary care unit. High-risk patients were identified if the electrocardiographic diagnoses included myocardial infarction, ischemia, left ventricular hypertrophy, left bundle-branch block, or paced rhythm. These 63 patients (29% of total) had significantly greater incidences of serious events, need for procedures, and death than low-risk patients whose initial electrocardiograms did not carry the above diagnoses. Patients with a low-risk initial electrocardiogram may not require the facilities of a coronary care unit and perhaps could be safely observed in an intermediate care area. However, many hospitals do not have an intermediate care facility available, and in those that do, daily costs may not be markedly different than for treatment in a coronary care unit. Whether these low-risk patients could be safely treated in general medicine beds, where potential cost savings would be much greater, is unknown.

Device therapy in heart failure with reduced ejection fraction-cardiac resynchronization therapy and more.

PubMed

Duncker, D; Veltmann, C

2018-05-09

In patients with heart failure with reduced ejection fraction (HFrEF), optimal medical treatment includes beta-blockers, ACE inhibitors/angiotensinreceptor-neprilysin inhibitors (ARNI), mineralocorticoid receptor antagonists, and ivabradine when indicated. In device therapy of HFrEF, implantable cardioverter-defibrillators and cardiac resynchronization therapy (CRT) have been established for many years. CRT is the therapy of choice (class I indication) in symptomatic patients with HFrEF and a broad QRS complex with a left bundle branch block (LBBB) morphology. However, the vast majority of heart failure patients show a narrow QRS complex or a non-LBBB morphology. These patients are not candidates for CRT and alternative electrical therapies such as baroreflex activation therapy (BAT) and cardiac contractility modulation (CCM) may be considered. BAT modulates vegetative dysregulation in heart failure. CCM improves contractility, functional capacity, and symptoms. Although a broad data set is available for BAT and CCM, mortality data are still lacking for both methods. This article provides an overview of the device-based therapeutic options for patients with HFrEF.

Electrocardiographic findings in Mexican chagasic subjects living in high and low endemic regions of Trypanosoma cruzi infection.

PubMed

Sosa-Jurado, Francisca; Mazariego-Aranda, Miguel; Hernández-Becerril, Nidia; Garza- Murillo, Verónica; Cárdenas, Manuel; Reyes, Pedro A; Hirayama, Kenji; Monteón, Victor M

2003-07-01

In México the first human chronic chagasic case was recognized in 1940. In spite of an increasing number of cases detected since that time, Chagas disease in México has been poorly documented. In the present work we studied 617 volunteers subjects living in high and low endemic regions of Trypanosoma cruzi infection with seroprevalence of 22% and 4% respectively. Hemoculture performed in those seropositive subjects failed to demonstrate circulating parasites, however polymerase chain reaction identified up to 60% of them as positives. A higher level of anti-T. cruzi antibodies was observed in seropositive residents in high endemic region, in spite of similar parasite persistence (p < 0.05). On standard 12 leads electrocardiogram (ECG) 20% to 22% seropositive individuals from either region showed right bundle branch block or ventricular extrasystoles which were more prevalent in seropositive than in seronegative individuals (p < 0.05). In conclusion, the frequency or type of ECG abnormality was influenced by serologic status but not by endemicity or parasite persistence. Furthermore, Mexican indeterminate patients have a similar ECG pattern to those reported in South America.

Non-responders to cardiac resynchronization therapy: Insights from multimodality imaging and electrocardiography. A brief review.

PubMed

Carità, Patrizia; Corrado, Egle; Pontone, Gianluca; Curnis, Antonio; Bontempi, Luca; Novo, Giuseppina; Guglielmo, Marco; Ciaramitaro, Gianfranco; Assennato, Pasquale; Novo, Salvatore; Coppola, Giuseppe

2016-12-15

Cardiac resynchronization therapy (CRT) is a successful strategy for heart failure (HF) patients. The pre-requisite for the response is the evidence of electrical dyssynchrony on the surface electrocardiogram usually as left bundle branch block (LBBB). Non-response to CRT is a significant problem in clinical practice. Patient selection, inadequate delivery and sub-optimal left ventricle lead position may be important causes. In an effort to improve CRT response multimodality imaging (especially echocardiography, computed tomography and cardiac magnetic resonance) could play a decisive role and extensive literature has been published on the matter. However, we are so far from routinary use in clinical practice. Electrocardiography (with respect to left ventricle capture and QRS narrowing) may represent a simple and low cost approach for early prediction of potential non-responder, with immediate practical implications. This brief review covers the current recommendations for CRT in HF patients with particular attention to the potential benefits of multimodality imaging and electrocardiography in improving response rate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Permanent Pacemaker Implantation after TAVR – Predictors and Impact on Outcomes

PubMed Central

Sinning, Jan-Malte; Hammerstingl, Christoph; Werner, Nikos; Grube, Eberhard; Nickenig, Georg

2015-01-01

The number of patients undergoing transcatheter aortic valve replacement (TAVR) worldwide is increasing steadily. Atrioventricular conduction disturbances, with or without the need for permanent pacemaker (PPM) implantation, are one of the most common adverse events after TAVR. Among transcatheter heart valves (THV), rates of conduction abnormalities vary from less than 10 % to more than 50 %. Depending on the reported data referred to, historical data showed that up to one-third of the patients required implantation of a PPM following TAVR. Although generally considered as a minor complication, PPM may have a profound impact on prognosis and quality of life after TAVR. Current data support the hypothesis that conduction abnormalities leading to pacemaker dependency result from mechanical compression of the conduction system by the prosthesis stent frame and individual predisposing conduction defects such as right bundle-branch block (RBBB). With several large randomised trials and registry studies having been published recently and second generation THV having been introduced, the debate about predictors for pacemaker implantation and their impact on outcome after TAVR is still ongoing. PMID:29588683

Toward a Global Bundle Adjustment of SPOT 5 - HRS Images

NASA Astrophysics Data System (ADS)

Massera, S.; Favé, P.; Gachet, R.; Orsoni, A.

2012-07-01

The HRS (High Resolution Stereoscopic) instrument carried on SPOT 5 enables quasi-simultaneous acquisition of stereoscopic images on wide segments - 120 km wide - with two forward and backward-looking telescopes observing the Earth with an angle of 20° ahead and behind the vertical. For 8 years IGN (Institut Géographique National) has been developing techniques to achieve spatiotriangulation of these images. During this time the capacities of bundle adjustment of SPOT 5 - HRS spatial images have largely improved. Today a global single block composed of about 20,000 images can be computed in reasonable calculation time. The progression was achieved step by step: first computed blocks were only composed of 40 images, then bigger blocks were computed. Finally only one global block is now computed. In the same time calculation tools have improved: for example the adjustment of 2,000 images of North Africa takes about 2 minutes whereas 8 hours were needed two years ago. To reach such a result a new independent software was developed to compute fast and efficient bundle adjustments. In the same time equipment - GCPs (Ground Control Points) and tie points - and techniques have also evolved over the last 10 years. Studies were made to get recommendations about the equipment in order to make an accurate single block. Tie points can now be quickly and automatically computed with SURF (Speeded Up Robust Features) techniques. Today the updated equipment is composed of about 500 GCPs and studies show that the ideal configuration is around 100 tie points by square degree. With such an equipment, the location of the global HRS block becomes a few meters accurate whereas non adjusted images are only 15 m accurate. This paper will describe the methods used in IGN Espace to compute a global single block composed of almost 20,000 HRS images, 500 GCPs and several million of tie points in reasonable calculation time. Many advantages can be found to use such a block. Because the global block is unique it becomes easier to manage the historic and the different evolutions of the computations (new images, new GCPs or tie points). The location is now unique and consequently coherent all around the world, avoiding steps and artifacts on the borders of DSMs (Digital Surface Models) and OrthoImages historically calculated from different blocks. No extrapolation far from GCPs in the limits of images is done anymore. Using the global block as a reference will allow new images from other sources to be easily located on this reference.

Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) onboard calibration system

NASA Technical Reports Server (NTRS)

Chrien, Thomas G.; Eastwood, Mike; Green, Robert O.; Sarture, Charles; Johnson, Howell; Chovit, Chris; Hajek, Pavel

1995-01-01

The AVIRIS instrument uses an onboard calibration system to provide auxiliary calibration data. The system consist of a tungsten halogen cycle lamp imaged onto a fiber bundle through an eight position filter wheel. The fiber bundle illuminates the back side of the foreoptics shutter during a pre-run and post-run calibration sequence. The filter wheel contains two neutral density filters, five spectral filters and one blocked position. This paper reviews the general workings of the onboard calibrator system and discusses recent modifications.

Bis-polymer lipid-peptide conjugates and nanoparticles thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Ting; Dong, He; Shu, Jessica

The present invention provides bis-polymer lipid-peptide conjugates containing a hydrophobic block and headgroup containing a helical peptide and two polymer blocks. The conjugates can self-assemble to form helix bundle subunits, which in turn assemble to provide micellar nanocarriers for drug cargos and other agents. Particles containing the conjugates and methods for forming the particles are also disclosed.

Rhizophores in Rhizophora mangle L: an alternative interpretation of so-called ''aerial roots''.

PubMed

Menezes, Nanuza L de

2006-06-01

Rhizophora mangle L., one of the most common mangrove species, has an aerial structure system that gives it stability in permanently swampy soils. In fact, these structures, known as "aerial roots" or "stilt roots", have proven to be peculiar branches with positive geotropism, which form a large number of roots when in contact with swampy soils. These organs have a sympodial branching system, wide pith, slightly thickened cortex, collateral vascular bundles, polyarch stele and endarch protoxylem, as in the stem, and a periderm produced by a phellogen at the apex similar to a root cap. They also have the same type of trichosclereid that occurs in the stem, with negative geotropism, unlike true Rhizophora roots, which do not form trichosclereids at all. On the other hand, these branches do not form leaves and in this respect they are similar to roots. These peculiar branches are rhizophores or special root-bearing branches, analogous to those found in Lepidodendrales and other Carboniferous tree ferns that grew in swampy soils.

41 CFR 50-204.3 - Material handling and storage.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Bags, containers, bundles, etc. stored in tiers shall be stacked, blocked, interlocked and limited in... provided on spur railroad tracks where a rolling car could contact other cars being worked, enter a...

41 CFR 50-204.3 - Material handling and storage.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Bags, containers, bundles, etc. stored in tiers shall be stacked, blocked, interlocked and limited in... provided on spur railroad tracks where a rolling car could contact other cars being worked, enter a...

41 CFR 50-204.3 - Material handling and storage.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Bags, containers, bundles, etc. stored in tiers shall be stacked, blocked, interlocked and limited in... provided on spur railroad tracks where a rolling car could contact other cars being worked, enter a...

41 CFR 50-204.3 - Material handling and storage.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Bags, containers, bundles, etc. stored in tiers shall be stacked, blocked, interlocked and limited in... provided on spur railroad tracks where a rolling car could contact other cars being worked, enter a...

41 CFR 50-204.3 - Material handling and storage.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Bags, containers, bundles, etc. stored in tiers shall be stacked, blocked, interlocked and limited in... provided on spur railroad tracks where a rolling car could contact other cars being worked, enter a...

Nerve block of articular branches of the obturator and femoral nerves for the treatment of hip joint pain.

PubMed

Yavuz, Ferdi; Yasar, Evren; Ali Taskaynatan, Mehmet; Goktepe, Ahmet Salim; Tan, Arif Kenan

2013-01-01

The aim of this retrospective study was to investigate the effectiveness of the nerve block of articular branches of obturator and femoral nerves in patients with intractable pain due to hip osteoarthritis. Twenty patients (8 female and 12 male; with a mean age 53.5 years) were retrospectively identified who had received nerve block of articular branches of obturator and femoral nerves for chronic hip joint pain due to hip osteoarthritis. The outcome measures (visual analogue pain scale, the level of patient satisfaction with nerve block, reduction rate of NSAID using) were assessed before the treatment and at the 1st and 3rd months after injection. Mean reduction in hip joint pain while walking and at night between the baseline and 1st month, and between the baseline and 3rd month were statistically significant (p< 0.05). At the 1st and 3rd months after treatment, the reduction rates of NSAID using were almost 67% and 71%; respectively. At the 1st and 3rd months after treatment, the level of patient satisfaction with nerve block were 73.00 ± 21.23 mm and 73.50 ± 18.14 mm; respectively. We found that nerve blocks of articular branches of obturator and femoral nerves were effective in short- and mid-term for reducing chronic hip joint pain.

Structural analysis of the role of TPX2 in branching microtubule nucleation

PubMed Central

Thawani, Akanksha

2017-01-01

The mitotic spindle consists of microtubules (MTs), which are nucleated by the γ-tubulin ring complex (γ-TuRC). How the γ-TuRC gets activated at the right time and location remains elusive. Recently, it was uncovered that MTs nucleate from preexisting MTs within the mitotic spindle, which requires the protein TPX2, but the mechanism basis for TPX2 action is unknown. Here, we investigate the role of TPX2 in branching MT nucleation. We establish the domain organization of Xenopus laevis TPX2 and define the minimal TPX2 version that stimulates branching MT nucleation, which we find is unrelated to TPX2’s ability to nucleate MTs in vitro. Several domains of TPX2 contribute to its MT-binding and bundling activities. However, the property necessary for TPX2 to induce branching MT nucleation is contained within newly identified γ-TuRC nucleation activator motifs. Separation-of-function mutations leave the binding of TPX2 to γ-TuRC intact, whereas branching MT nucleation is abolished, suggesting that TPX2 may activate γ-TuRC to promote branching MT nucleation. PMID:28264915

Clinical and electrophysiological characteristics of patients with paroxysmal intra-His block with narrow QRS complexes.

PubMed

Ragupathi, Loheetha; Johnson, Drew; Greenspon, Arnold; Frisch, Daniel; Ho, Reginald T; Pavri, Behzad B

2018-04-18

Atrioventricular (AV) block is usually due to infranodal disease and associated with a wide QRS complex; such patients often progress to complete AV block and pacemaker dependency. Uncommonly, infranodal AV block can occur within the His bundle with a narrow QRS complex. The aims of this study were to define clinical/echocardiographic characteristics of patients with AV block within the His bundle and report progression to pacemaker dependency. We retrospectively identified patients with narrow QRS complexes and documented intra-His delay or block at electrophysiology study (group A) or with electrocardiogram-documented Mobitz II AV block/paroxysmal AV block (group B). Clinical, electrophysiological, and echocardiographic variables at presentation and pacemaker parameters at the last follow-up visit were evaluated. Twenty-seven patients (19 women) were identified (mean age 64 ± 13 years; range, 38-85 years). Four patients who had <1 month of follow-up were excluded. There were 12 patients in group A and 11 in group B; 21 of 23 presented with syncope/presyncope. All patients received pacemakers: 8 single chamber and 15 dual chamber. After a median follow-up of 6.4 years, the median percentage of ventricular pacing was 1% (interquartile range 0%-4.66%). One patient developed true pacemaker dependency. Aortic and/or mitral annular calcification was present in 13 of 22 patients with available echocardiograms. Patients who present with syncope and narrow QRS complexes with intra-His delay or Mobitz II paroxysmal AV block with narrow QRS complexes rarely progress to pacemaker dependency and require infrequent pacing. This entity is more common in women, with a higher prevalence of aortic and/or mitral annular calcification. If confirmed by additional studies, single-chamber pacemaker may be sufficient. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Electrocardiogram: his bundle potentials can be recorded noninvasively beat by beat on surface electrocardiogram.

PubMed

Wang, Gaopin; Liu, Renguang; Chang, Qinghua; Xu, Zhaolong; Zhang, Yingjie; Pan, Dianzhu

2017-03-15

The micro waveform of His bundle potential can't be recorded beat-to-beat on surface electrocardiogram yet. We have found that the micro-wavelets before QRS complex may be related to atrioventricular conduction system potentials. This study is to explore the possibility of His bundle potential can be noninvasively recorded on surface electrocardiogram. We randomized 65 patients undergoing radiofrequency catheter ablation of paroxysmal superventricular tachycardia (exclude overt Wolff-Parkinson-White syndrome) to receive "conventional electrocardiogram" and "new electrocardiogram" before the procedure. His bundle electrogram was collected during the procedure. Comparative analysis of PA s (PA interval recorded on surface electrocardiogram), AH s (AH interval recorded on surface electrocardiogram) and HV s (HV interval recorded on surface electrocardiogram) interval recorded on surface "new electrocardiogram" and PA, AH, HV interval recorded on His bundle electrogram was investigated. There was no difference (P > 0.05) between groups in HV s interval (49.63 ± 6.19 ms) and HV interval (49.35 ± 6.49 ms). Results of correlational analysis found that HV S interval was significantly positively associated with HV interval (r = 0.929; P < 0.01). His bundle potentials can be noninvasively recorded on surface electrocardiogram. Noninvasive His bundle potential tracing might represent a new method for locating the site of atrioventricular block and identifying the origin of a wide QRS complex.

The Role of Thoracic Medial Branch Blocks in Managing Chronic Mid and Upper Back Pain: A Randomized, Double-Blind, Active-Control Trial with a 2-Year Followup

PubMed Central

Manchikanti, Laxmaiah; Singh, Vijay; Falco, Frank J. E.; Cash, Kimberly A.; Pampati, Vidyasagar; Fellows, Bert

2012-01-01

Study Design. A randomized, double-blind, active-control trial. Objective. To determine the clinical effectiveness of therapeutic thoracic facet joint nerve blocks with or without steroids in managing chronic mid back and upper back pain. Summary of Background Data. The prevalence of thoracic facet joint pain has been established as 34% to 42%. Multiple therapeutic techniques utilized in managing chronic thoracic pain of facet joint origin include medial branch blocks, radiofrequency neurotomy, and intraarticular injections. Methods. This randomized double-blind active controlled trial was performed in 100 patients with 50 patients in each group who received medial branch blocks with local anesthetic alone or local anesthetic and steroids. Outcome measures included the numeric rating scale (NRS), Oswestry Disability Index (ODI), opioid intake, and work status, at baseline, 3, 6, 12, 18, and 24 months. Results. Significant improvement with significant pain relief and functional status improvement of 50% or more were observed in 80% of the patients in Group I and 84% of the patients in Group II at 2-year followup. Conclusions. Therapeutic medial branch blocks of thoracic facets with or without steroids may provide a management option for chronic function-limiting thoracic pain of facet joint origin. PMID:22851967

Novel insights into the distribution of cardiac HCN channels: an expression study in the mouse heart.

PubMed

Herrmann, Stefan; Layh, Beate; Ludwig, Andreas

2011-12-01

HCN pacemaker channels (I(f) channels) are believed to contribute to important functions in the heart; thus these channels became an attractive target for generating transgenic mouse mutants to elucidate their role in physiological and pathophysiological cardiac conditions. A full understanding of cardiac I(f) and the interpretation of studies using HCN mouse mutants require detailed information about the expression profile of the individual HCN subunits. Here we investigate the cardiac expression pattern of the HCN isoforms at the mRNA as well as at the protein level. The specificity of antibodies used was strictly confirmed by the use of HCN1, HCN2 and HCN4 knockout animals. We find a low, but highly differential HCN expression profile outside the cardiac conduction pathway including left and right atria and ventricles. Additionally HCN distribution was investigated in tissue slices of the sinoatrial node, the atrioventricular node, the bundle of His and the bundle branches. The conduction system was marked by acetylcholine esterase staining. HCN4 was confirmed as the predominant isoform of the primary pacemaker followed by a distinct expression of HCN1. In contrast HCN2 shows only a confined expression to individual pacemaker cells. Immunolabeling of the AV-node reveals also a pronounced specificity for HCN1 and HCN4. Compared to the SN and AVN we found a low but selective expression of HCN4 as the only isoform in the atrioventricular bundle. However in the bundle branches HCN1, HCN4 and also HCN2 show a prominent and selective expression pattern. Our results display a characteristic distribution of individual HCN isoforms in several cardiac compartments and reveal that beside HCN4, HCN1 represents the isoform which is selectively expressed in most parts of the conduction system suggesting a substantial contribution of HCN1 to pacemaking. 2011 Elsevier Ltd. All rights reserved.

Dianthus chinensis L.: The Structural Difference between Vascular Bundles in the Placenta and Ovary Wall Suggests Their Different Origin

PubMed Central

Guo, Xue-Min; Yu, Ying-Ying; Bai, Lan; Gao, Rong-Fu

2017-01-01

Dianthus chinensis is a perennial herbaceous plant with great ornamental, botanical, ecological, and medicinal value. The pistil of D. chinensis is composed of two fused carpels with free central placenta and two separate styles. The placenta is a columnar structure extending about two-thirds the length of the maturing fruit, which is typical of the Caryophyllaceous. Traditionally, free central placenta is thought to have evolved from axial placenta by septal disappearance, and axial placenta to have occurred through fusion of conduplicate carpels with marginal placenta. However, the traditional opinion is becoming more and more inconsistent with the new data gained in recent research of angiosperm systematics. To clarify the origin of D. chinensis pistil, the present anatomical study was carried out. The results show that the vascular system of placenta is independent to that of the ovary wall in D. chinensis. Moreover, in the central part of placenta there are one or two amphicribral bundles, and correspondingly numerous ones in the pistil which supply the ovules/seeds. It is obvious that the central amphicribral bundles in placenta are comparable to the counterparts in branches but not to those in leaves or their derivatives. Therefore, it is reasonable to deduce that the placenta of D. chinensis was not derived from conduplicate carpels through fusion of collateral vascular bundles, and actually a floral axis with ovules/seeds laterally adhering. On the contrary, the ovary wall was the lateral appendages of the floral axis. The result of the present study is completely in agreement with Unifying Theory, in which the placenta is taken as an ovule-bearing branch. Except for D. chinensis, the similar vascular organization has been observed in placenta of numerous isolated taxa. But till now, it is uncertain that whether this vascular organization pattern is popular in the whole angiosperms or not. More intensive and extensive investigations are needed. PMID:29250086

Dianthus chinensis L.: The Structural Difference between Vascular Bundles in the Placenta and Ovary Wall Suggests Their Different Origin.

PubMed

Guo, Xue-Min; Yu, Ying-Ying; Bai, Lan; Gao, Rong-Fu

2017-01-01

Dianthus chinensis is a perennial herbaceous plant with great ornamental, botanical, ecological, and medicinal value. The pistil of D. chinensis is composed of two fused carpels with free central placenta and two separate styles. The placenta is a columnar structure extending about two-thirds the length of the maturing fruit, which is typical of the Caryophyllaceous. Traditionally, free central placenta is thought to have evolved from axial placenta by septal disappearance, and axial placenta to have occurred through fusion of conduplicate carpels with marginal placenta. However, the traditional opinion is becoming more and more inconsistent with the new data gained in recent research of angiosperm systematics. To clarify the origin of D. chinensis pistil, the present anatomical study was carried out. The results show that the vascular system of placenta is independent to that of the ovary wall in D. chinensis . Moreover, in the central part of placenta there are one or two amphicribral bundles, and correspondingly numerous ones in the pistil which supply the ovules/seeds. It is obvious that the central amphicribral bundles in placenta are comparable to the counterparts in branches but not to those in leaves or their derivatives. Therefore, it is reasonable to deduce that the placenta of D. chinensis was not derived from conduplicate carpels through fusion of collateral vascular bundles, and actually a floral axis with ovules/seeds laterally adhering. On the contrary, the ovary wall was the lateral appendages of the floral axis. The result of the present study is completely in agreement with Unifying Theory, in which the placenta is taken as an ovule-bearing branch. Except for D. chinensis , the similar vascular organization has been observed in placenta of numerous isolated taxa. But till now, it is uncertain that whether this vascular organization pattern is popular in the whole angiosperms or not. More intensive and extensive investigations are needed.

Effective System for Automatic Bundle Block Adjustment and Ortho Image Generation from Multi Sensor Satellite Imagery

NASA Astrophysics Data System (ADS)

Akilan, A.; Nagasubramanian, V.; Chaudhry, A.; Reddy, D. Rajesh; Sudheer Reddy, D.; Usha Devi, R.; Tirupati, T.; Radhadevi, P. V.; Varadan, G.

2014-11-01

Block Adjustment is a technique for large area mapping for images obtained from different remote sensingsatellites.The challenge in this process is to handle huge number of satellite imageries from different sources with different resolution and accuracies at the system level. This paper explains a system with various tools and techniques to effectively handle the end-to-end chain in large area mapping and production with good level of automation and the provisions for intuitive analysis of final results in 3D and 2D environment. In addition, the interface for using open source ortho and DEM references viz., ETM, SRTM etc. and displaying ESRI shapes for the image foot-prints are explained. Rigorous theory, mathematical modelling, workflow automation and sophisticated software engineering tools are included to ensure high photogrammetric accuracy and productivity. Major building blocks like Georeferencing, Geo-capturing and Geo-Modelling tools included in the block adjustment solution are explained in this paper. To provide optimal bundle block adjustment solution with high precision results, the system has been optimized in many stages to exploit the full utilization of hardware resources. The robustness of the system is ensured by handling failure in automatic procedure and saving the process state in every stage for subsequent restoration from the point of interruption. The results obtained from various stages of the system are presented in the paper.

Assembly of tobacco mosaic virus into fibrous and macroscopic bundled arrays mediated by surface aniline polymerization.

PubMed

Niu, Zhongwei; Bruckman, Michael A; Li, Siqi; Lee, L Andrew; Lee, Byeongdu; Pingali, Sai Venkatesh; Thiyagarajan, P; Wang, Qian

2007-06-05

One-dimensional (1D) polyaniline/tobacco mosaic virus (TMV) composite nanofibers and macroscopic bundles of such fibers were generated via a self-assembly process of TMV assisted by in-situ polymerization of polyaniline on the surface of TMV. At near-neutral reaction pH, branched polyaniline formed on the surface of TMV preventing lateral association. Therefore, long 1D nanofibers were observed with high aspect ratios and excellent processibility. At a lower pH, transmission electron microscopy (TEM) analysis revealed that initially long nanofibers were formed which resulted in bundled structures upon long-time reaction, presumably mediated by the hydrophobic interaction because of the polyaniline on the surface of TMV. In-situ time-resolved small-angle X-ray scattering study of TMV at different reaction conditions supported this mechanism. This novel strategy to assemble TMV into 1D and 3D supramolecular composites could be utilized in the fabrication of advanced materials for potential applications including electronics, optics, sensing, and biomedical engineering.

Biomechanics of selected arborescent and shrubby monocotyledons

PubMed Central

Haushahn, Tobias; Fink, Samuel; Speck, Thomas

2016-01-01

Main aims of the study are a deepened understanding of the mechanically relevant (ultra-)structures and the mechanical behaviour of various arborescent and shrubby monocotyledons and obtaining the structure–function relationships of different structurally conspicuous parts in Dracaena marginata stems. The stems of five different “woody” monocotyledon species were dissected and the mechanical properties of the most noticeable tissues in the five monocotyledons and, additionally, of individual vascular bundles in D. marginata, were tested under tensile stress. Results for Young’s moduli and density of these tissues were assessed as well as the area, critical strain, Young’s modulus and tensile strength of the vascular bundles in Dracaena marginata. These analyses allowed for generating a model for the mechanical interaction of tissues and vascular bundles of the stem in D. marginata as well as filling major “white spots” in property charts for biological materials. Additionally we shortly discuss the potential significance of such studies for the development of branched and unbranched bio-inspired fibre-reinforced materials and structures with enhanced properties. PMID:28144511

Three-Dimensional Computer Model of the Right Atrium Including the Sinoatrial and Atrioventricular Nodes Predicts Classical Nodal Behaviours

PubMed Central

Li, Jue; Inada, Shin; Schneider, Jurgen E.; Zhang, Henggui; Dobrzynski, Halina; Boyett, Mark R.

2014-01-01

The aim of the study was to develop a three-dimensional (3D) anatomically-detailed model of the rabbit right atrium containing the sinoatrial and atrioventricular nodes to study the electrophysiology of the nodes. A model was generated based on 3D images of a rabbit heart (atria and part of ventricles), obtained using high-resolution magnetic resonance imaging. Segmentation was carried out semi-manually. A 3D right atrium array model (∼3.16 million elements), including eighteen objects, was constructed. For description of cellular electrophysiology, the Rogers-modified FitzHugh-Nagumo model was further modified to allow control of the major characteristics of the action potential with relatively low computational resource requirements. Model parameters were chosen to simulate the action potentials in the sinoatrial node, atrial muscle, inferior nodal extension and penetrating bundle. The block zone was simulated as passive tissue. The sinoatrial node, crista terminalis, main branch and roof bundle were considered as anisotropic. We have simulated normal and abnormal electrophysiology of the two nodes. In accordance with experimental findings: (i) during sinus rhythm, conduction occurs down the interatrial septum and into the atrioventricular node via the fast pathway (conduction down the crista terminalis and into the atrioventricular node via the slow pathway is slower); (ii) during atrial fibrillation, the sinoatrial node is protected from overdrive by its long refractory period; and (iii) during atrial fibrillation, the atrioventricular node reduces the frequency of action potentials reaching the ventricles. The model is able to simulate ventricular echo beats. In summary, a 3D anatomical model of the right atrium containing the cardiac conduction system is able to simulate a wide range of classical nodal behaviours. PMID:25380074

Chagasic cardiomyopathy and Pompe disease: case report

PubMed Central

de Morais, Rafael OB; Chaves-Markman, Ândrea V; Miranda, Anna PP; Amorim, Ingrid G; Cavalcanti, Maria da GA de M; Markman, Manuel; Markman-Filho, Brivaldo

2018-01-01

Background: Pompe disease is a lysosomal storage disease with an autosomal recessive inheritance characterized by an insufficient activity of the acid alpha-glucosidase enzyme. The incidence varies from 1:40000 to 1:200000 live births and cardiac involvement in adults is rare. Chagas disease is an infection caused by the protozoan Trypanosoma cruzi, in which one-third of the cases progress to the chronic form, and may lead to cardiac involvement, usually from the fifth decade of life onwards. We report a case of a patient with Chagas and Pompe diseases who had early cardiac involvement and rapid evolution to heart failure. Case report: A 43-year-old male patient with a history of ischemic stroke at 28 years with gait ataxia sequelae. A few years after the episode, he experienced gait impairment and difficulty climbing stairs, attributed to stroke. A family screening for Pompe disease was carried out years later, and thus the diagnosis was made. As for Chagas disease, the investigation was performed because the patient lives in an endemic area. The cardiovascular physical examination did not show significant changes. The electrocardiogram showed sinus rhythm with left bundle branch block and first-degree atrioventricular block; the transthoracic echocardiogram demonstrated left ventricular systolic dysfunction; the Holter monitoring showed several episodes of ventricular tachycardia. The patient is undergoing optimized treatment for heart failure and enzyme replacement therapy for Pompe disease. Conclusion: Cardiomyopathy with early onset and with rapid evolution suggests overlap of the two diseases. PMID:29755837

Prognostic implications of stress hyperglycemia in acute ST elevation myocardial infarction. Prospective observational study.

PubMed

Sanjuán, Rafael; Núñez, Julio; Blasco, M Luisa; Miñana, Gema; Martínez-Maicas, Helena; Carbonell, Nieves; Palau, Patricia; Bodí, Vicente; Sanchis, Juan

2011-03-01

In patients with acute myocardial infarction, elevation of plasma glucose levels is associated with worse outcomes. The aim of this study was to evaluate the association between stress hyperglycemia and in-hospital mortality in patients with acute myocardial infarction with ST-segment elevation (STEMI). We analyzed 834 consecutive patients admitted for STEMI to the Coronary Care Unit of our center. Association between admission glucose and mortality was assessed with Cox regression analysis. Discriminative accuracy of the multivariate model was assessed by Harrell's C statistic. Eighty-nine (10.7%) patients died during hospitalization. Optimal threshold glycemia level of 140mg/dl on admission to predict mortality was obtained by ROC curves. Those who presented glucose ≥140mg/dl showed higher rates of malignant ventricular tachyarrhythmias (28% vs. 18%, P=.001), complicative bundle branch block (5% vs. 2%, P=.005), new atrioventricular block (9% vs. 5%, P=.05) and in-hospital mortality (15% vs. 5%, P<.001). Multivariate analysis showed that those with glycemia ≥140mg/dl exhibited a 2-fold increase of in-hospital mortality risk (95% CI: 1.2-3.5, P=.008) irrespective of diabetes mellitus status (P-value for interaction=0.487 and 0.653, respectively). Stress hyperglycemia on admission is a predictor of mortality and arrhythmias in patients with STEMI and could be used in the stratification of risk in these patients. Copyright © 2010 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Differential clinical characteristics and prognosis of intraventricular conduction defects in patients with chronic heart failure.

PubMed

Cinca, Juan; Mendez, Ana; Puig, Teresa; Ferrero, Andreu; Roig, Eulalia; Vazquez, Rafael; Gonzalez-Juanatey, Jose R; Alonso-Pulpon, Luis; Delgado, Juan; Brugada, Josep; Pascual-Figal, Domingo

2013-08-01

Intraventricular conduction defects (IVCDs) can impair prognosis of heart failure (HF), but their specific impact is not well established. This study aimed to analyse the clinical profile and outcomes of HF patients with LBBB, right bundle branch block (RBBB), left anterior fascicular block (LAFB), and no IVCDs. Clinical variables and outcomes after a median follow-up of 21 months were analysed in 1762 patients with chronic HF and LBBB (n = 532), RBBB (n = 134), LAFB (n = 154), and no IVCDs (n = 942). LBBB was associated with more marked LV dilation, depressed LVEF, and mitral valve regurgitation. Patients with RBBB presented overt signs of congestive HF and depressed right ventricular motion. The LAFB group presented intermediate clinical characteristics, and patients with no IVCDs were more often women with less enlarged left ventricles and less depressed LVEF. Death occurred in 332 patients (interannual mortality = 10.8%): cardiovascular in 257, extravascular in 61, and of unknown origin in 14 patients. Cardiac death occurred in 230 (pump failure in 171 and sudden death in 59). An adjusted Cox model showed higher risk of cardiac death and pump failure death in the LBBB and RBBB than in the LAFB and the no IVCD groups. LBBB and RBBB are associated with different clinical profiles and both are independent predictors of increased risk of cardiac death in patients with HF. A more favourable prognosis was observed in patients with LAFB and in those free of IVCDs. Further research in HF patients with RBBB is warranted.

Does my patient have chronic Chagas disease? Development and temporal validation of a diagnostic risk score.

PubMed

Brasil, Pedro Emmanuel Alvarenga Americano do; Xavier, Sergio Salles; Holanda, Marcelo Teixeira; Hasslocher-Moreno, Alejandro Marcel; Braga, José Ueleres

2016-01-01

With the globalization of Chagas disease, unexperienced health care providers may have difficulties in identifying which patients should be examined for this condition. This study aimed to develop and validate a diagnostic clinical prediction model for chronic Chagas disease. This diagnostic cohort study included consecutive volunteers suspected to have chronic Chagas disease. The clinical information was blindly compared to serological tests results, and a logistic regression model was fit and validated. The development cohort included 602 patients, and the validation cohort included 138 patients. The Chagas disease prevalence was 19.9%. Sex, age, referral from blood bank, history of living in a rural area, recognizing the kissing bug, systemic hypertension, number of siblings with Chagas disease, number of relatives with a history of stroke, ECG with low voltage, anterosuperior divisional block, pathologic Q wave, right bundle branch block, and any kind of extrasystole were included in the final model. Calibration and discrimination in the development and validation cohorts (ROC AUC 0.904 and 0.912, respectively) were good. Sensitivity and specificity analyses showed that specificity reaches at least 95% above the predicted 43% risk, while sensitivity is at least 95% below the predicted 7% risk. Net benefit decision curves favor the model across all thresholds. A nomogram and an online calculator (available at http://shiny.ipec.fiocruz.br:3838/pedrobrasil/chronic_chagas_disease_prediction/) were developed to aid in individual risk estimation.

Studies on sodium boiling phenomena in out of pile rod bundles for various accidental situations in Liquid Metal Fast Breeder Reactors (LMFBR) experiments and interpretations

NASA Astrophysics Data System (ADS)

Seiler, J. M.; Rameau, B.

Bundle sodium boiling in nominal geometry for different accident conditions is reviewed. Voiding of a subassembly is controlled by not only hydrodynamic effects but mainly by thermal effects. There is a strong influence of the thermal inertia of the bundle material compared to the sodium thermal inertia. Flow instability, during a slow transient, can be analyzed with numerical tools and estimated using simplified approximations. Stable boiling operational conditions under bundle mixed convection (natural convection in the reactor) can be predicted. Voiding during a fast transient can be approximated from single channel calculations. The phenomenology of boiling behavior for a subassembly with inlet completely blocked, submitted to decay heat and lateral cooling; two-phase sodium flow pressure drop in a tube of large hydraulic diameter under adiabatic conditions; critical flow phenomena and voiding rate under high power, slow transient conditions; and onset of dry out under local boiling remains problematical.

Distribution, Innervation, and Cellular Organization of Taste Buds in the Sea Catfish, Plotosus japonicus.

PubMed

Nakamura, Tatsufumi; Matsuyama, Naoki; Kirino, Masato; Kasai, Masanori; Kiyohara, Sadao; Ikenaga, Takanori

2017-01-01

The gustatory system of the sea catfish Plotosus japonicus, like that of other catfishes, is highly developed. To clarify the details of the morphology of the peripheral gustatory system of Plotosus, we used whole-mount immunohistochemistry to investigate the distribution and innervation of the taste buds within multiple organs including the barbels, oropharyngeal cavity, fins (pectoral, dorsal, and caudal), and trunk. Labeled taste buds could be observed in all the organs examined. The density of the taste buds was higher along the leading edges of the barbels and fins; this likely increases the chance of detecting food. In all the fins, the taste buds were distributed in linear arrays parallel to the fin rays. Labeling of nerve fibers by anti-acetylated tubulin antibody showed that the taste buds within each sensory field are innervated in different ways. In the barbels, large nerve bundles run along the length of the organ, with fascicles branching off to innervate polygonally organized groups of taste buds. In the fins, nerve bundles run along the axis of fin rays to innervate taste buds lying in a line. In each case, small fascicles of fibers branch from large bundles and terminate within the basal portions of the taste buds. Serotonin immunohistochemistry demonstrated that most of the taste buds in all the organs examined contained disk-shaped serotonin-immunopositive cells in their basal region. This indicates a similar organization of the taste buds, in terms of the existence of serotonin-immunopositive basal cells, across the different sensory fields in this species. © 2017 S. Karger AG, Basel.

Visualizing anatomical evidences on atrioventricular conduction system for TAVI.

PubMed

Kawashima, Tomokazu; Sato, Fumi

2014-06-01

Visualizing the anatomy of the atrioventricular (AV) conduction axis substantiates that there is remarkable inter-individual variation at the macro- and microscopic levels, and that the atrioventricular bundle and left bundle branch are located more anteriorly, distally, and cranially and much closer to the aortic root complex than previously thought. The AV conduction system may therefore be compromised during implantation of a transcatheter aortic valve prosthesis, which may account for the relatively high incidence of new cardiac conduction abnormalities when conventional prosthetic valves are used. The design of the newer JenaValve® may afford advantages over more conventional valves by avoiding the high-risk implantation area and the potential for coronary ostia obstruction. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Workshop on Principles and Practice of Constraint Programming (2nd) Held in Orcas Island, Washington on 2-4 May 1994

DTIC Science & Technology

1994-05-04

gen- word pussies . In Proceedings of the Eighth Na- erate fewer than c clauses so the boundary of the grid tional Conference on Artificial Intelligence...checking. (2) (FC - NI), forward-checking search branches are bundled and visited once. with the advantage of neighborhood inter- If a dead -end occurs

Conformal Nets II: Conformal Blocks

NASA Astrophysics Data System (ADS)

Bartels, Arthur; Douglas, Christopher L.; Henriques, André

2017-08-01

Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

The benefit of therapeutic medial branch blocks after cervical operations.

PubMed

Klessinger, Stephan

2010-01-01

Persistent neck pain is a common problem after surgery of the cervical spine. No therapy recommendation exists for these patients. The objective of this study was to determine if a therapeutic medial branch block is a rational treatment for patients with postoperative neck pain after cervical spine operations. Retrospective practice audit. Review of charts of all patients who underwent cervical spine operations for degenerative reasons during a time period of 3 years. Patients with persistent postsurgical pain were treated with therapeutic medial branch blocks (local anesthetic and steroid). A positive treatment response was defined if at least 80% reduction of pain could be achieved or if the patient was sufficiently satisfied with the relief. All patients with a minimum follow up time of 6 months were included. Of the 312 operations performed, 128 were artificial disc operations, 125 were stand alone cages, and 59 were fusions with cage and plate. Persistent neck pain occurred in 33.3% of the patients. There was no difference between the patients with neck pain and the whole group of patients. More than half of the patients with neck pain--52.9%--were treated successfully with therapeutic medial branch blocks. Since no further treatment was necessary, the initial treatment was considered successful. Nearly a third--32.2%--of the patients were initially treated successfully, but their pain recurred and further diagnostics and treatments were necessary. In this group of patients, significantly more with double level operations were found (P = 0.003). Patients not responding to the medial branch block were 14.9%. This audit is retrospective and observational, and therefore does not represent a high level of evidence. However, to our knowledge, since this information has not been previously reported and no recommendation for the treatment of post-operative zygapophysial joint pain exists, it appears to be the best available research upon which to recommend treatment and to plan higher quality studies. For persistent postsurgical neck pain only limited therapy recommendations exist. This study suggests treating these patients in a first instance with therapeutic medial branch blocks. The success rate is 52.9 %.

Automated detection of heart ailments from 12-lead ECG using complex wavelet sub-band bi-spectrum features

PubMed Central

Dandapat, Samarendra

2017-01-01

The complex wavelet sub-band bi-spectrum (CWSB) features are proposed for detection and classification of myocardial infarction (MI), heart muscle disease (HMD) and bundle branch block (BBB) from 12-lead ECG. The dual tree CW transform of 12-lead ECG produces CW coefficients at different sub-bands. The higher-order CW analysis is used for evaluation of CWSB. The mean of the absolute value of CWSB, and the number of negative phase angle and the number of positive phase angle features from the phase of CWSB of 12-lead ECG are evaluated. Extreme learning machine and support vector machine (SVM) classifiers are used to evaluate the performance of CWSB features. Experimental results show that the proposed CWSB features of 12-lead ECG and the SVM classifier are successful for classification of various heart pathologies. The individual accuracy values for MI, HMD and BBB classes are obtained as 98.37, 97.39 and 96.40%, respectively, using SVM classifier and radial basis function kernel function. A comparison has also been made with existing 12-lead ECG-based cardiac disease detection techniques. PMID:28894589

Recent advances in pacemaker and implantable defibrillator therapy for young patients.

PubMed

Walsh, Edward P; Cecchin, Frank

2004-03-01

This review is intended to highlight major clinical advances over the past year related to (1). biventricular pacing as a treatment for dilated myopathy, (2). growing clinical experience with implantable cardioverter defibrillators in pediatrics, (3). technical advances in standard antibradycardia pacing, and (4). an appraisal of the newly updated ACC/AHA/NASPE guidelines for device implant in children and adolescents. Complex rhythm devices are being used more frequently in children. Biventricular pacing to improve ventricular contractility is a rapidly evolving technology that has now been applied to children and young adults with intraventricular conduction delay, such as bundle branch block after cardiac surgery. Implantable defibrillators are also being used for an expanding list of conditions, although lead dysfunction is seen as a fairly common complication in active young patients. Guidelines for device implantation have been developed, but the weight of evidence remains somewhat limited by the paucity of pediatric data in this field. Thanks to refinements in lead design and generator technology, coupled with rapidly expanding clinical indications, pacemakers and implantable defibrillators have become increasingly important components of cardiac therapy for young patients. Expanded multicenter clinical studies will be needed to develop more objective guidelines for use of this advanced technology.

Man in his 50s with chest pain and dyspnoea.

PubMed

Obayashi, Yuki; Izumi, Chisato; Nakagawa, Yoshihisa

2018-05-01

A man in his 50s with sudden-onset chest pain and dyspnoea was transferred to the emergency room. He had a history of aortic valve replacement due to aortic regurgitation with a mechanical valve 6 years previously. Heart rate was 90 bpm, and blood pressure was too low to measure. In the emergency room, he presented with severe dyspnoea and a chest X-ray showed severe lung congestion (figure 1A). ECG showed complete left bundle branch block. His respiratory status rapidly worsened, and he went into cardiopulmonary arrest. After cardiopulmonary resuscitation, transthoracic echocardiography was performed (figure 1B, online supplementary video 1).DC1SP110.1136/heartjnl-2017-312477.supp1Supplementary file 1 heartjnl;104/10/868/F1F1F1Figure 1(A) Chest X-ray. (B) Colour Doppler image from apical five-chamber view. What is the most likely cause of the patient's cardiopulmonary arrest?Myocardial infarction in left main trunkAortic dissectionProsthetic valve thrombosisProsthetic valve embolisationPulmonary embolism. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Potential role of biventricular pacing beyond advanced systolic heart failure.

PubMed

Fang, Fang; Sanderson, John E; Yu, Cheuk-Man

2013-01-01

Cardiac resynchronization therapy (CRT) is an effective therapy for advanced heart failure (HF) patients. The indications are well defined in recent guidelines and broadly indicate that CRT is suitable for chronic HF patients with left ventricular ejection fraction (EF) ≤35% and in NYHA class III or IV (Class I), and those with prolonged QRS duration ≥120 ms with left bundle branch block (LBBB) QRS morphology, or QRS duration ≥150 ms irrespective of QRS morphology (Class IIa). For patients with NYHA class II symptoms, CRT is recommended for patients with EF ≤30% and QRS duration ≥130 ms with LBBB QRS morphology (Class I, level of evidence: A), or QRS duration ≥150 ms irrespective of QRS morphology (Class IIa, level of evidence: A). However, CRT may benefit additional patients outside these criteria. In this review, we summarize the role of CRT in some subgroups, including patients with mild and moderate HF, upgrading to CRT from right ventricular (RV) pacing, bradycardia patients with routine pacing indications, congenital heart disease and specific cardiomyopathies. It is possible that CRT can give symptomatic and mortality benefits in some of these subgroups in the future and further clinical trials are warranted.  

Case report: an electrocardiogram of spontaneous pneumothorax mimicking arm lead reversal.

PubMed

Wieters, J Scott; Carlin, Joseph P; Morris, Andrew

2014-05-01

There are several previously documented findings for electrocardiograms (ECGs) of spontaneous pneumothorax. These findings include axis deviation, T-wave inversion, and right bundle branch block. When an ECG has the arm leads incorrectly placed, the ECG will display right axis deviation and inversion of the P waves in lead I. There have been no previously published ECGs of spontaneous pneumothorax that have shown the same findings as reversal of the limb leads of an ECG. A possible finding of spontaneous pneumothorax is an identical finding to that of an ECG that has been flagged for limb lead reversal. A patient presented in the emergency setting with acute chest pain and shortness of breath caused by a tension pneumothorax. An ECG was administered; findings indicated reversal of the arm leads (right axis deviation and inverted P waves in lead I), but there was no actual limb lead reversal present. ECG findings resolved upon resolution of the pneumothorax. If a patient presents with chest pain and shortness of breath, and the patient's ECG is flagged for limb lead reversal despite being set up correctly, the physician should raise clinical suspicion for a possible spontaneous pneumothorax. Copyright © 2014 Elsevier Inc. All rights reserved.

Heterogeneities in Myocardial Flow and Metabolism: Exacerbation with Abnormal Excitation

PubMed Central

Bassingthwaighte, James B.; Li, Zheng

2010-01-01

Because regional myocardial blood flows are remarkably heterogeneous—with a 6- to 10-fold range of flows in normal hearts—and because the spatial profiles of the flows are stable over long periods and over a range of conditions, the relation between flows and other physiologic functions has been explored. Local fatty acid uptake and oxygen consumption are almost linearly related to the flows. Coronary network structure and hydrodynamic resistances give suitable flow heterogeneity but are thought to be a response to local needs rather than being causative. Presumably the cause is the need for adenosine triphosphate (ATP) synthesis locally, and therefore flows, substrate delivery, and oxygen utilization are driven primarily by local rates of ATP hydrolysis, mainly by contractile proteins. This hypothesis is by no means fully tested. Data on pacing dog hearts from different sites, on patients with left bundle branch block, and on unloading transplanted rat hearts, all point in the same direction: unloading ventricular muscle leads to diminished flow and exaggeratedly diminished glucose uptake. The mechanism is likely to be that discovered by Taegtmeyer and colleagues, namely, the expression of fetal genes in regions where the muscle is unloaded and particular metabolic enzymes and transporters are downregulated. PMID:10750580

Optimizing the Distribution of Tie Points for the Bundle Adjustment of HRSC Image Mosaics

NASA Astrophysics Data System (ADS)

Bostelmann, J.; Breitkopf, U.; Heipke, C.

2017-07-01

For a systematic mapping of the Martian surface, the Mars Express orbiter is equipped with a multi-line scanner: Since the beginning of 2004 the High Resolution Stereo Camera (HRSC) regularly acquires long image strips. By now more than 4,000 strips covering nearly the whole planet are available. Due to the nine channels, each with different viewing direction, and partly with different optical filters, each strip provides 3D and color information and allows the generation of digital terrain models (DTMs) and orthophotos. To map larger regions, neighboring HRSC strips can be combined to build DTM and orthophoto mosaics. The global mapping scheme Mars Chart 30 is used to define the extent of these mosaics. In order to avoid unreasonably large data volumes, each MC-30 tile is divided into two parts, combining about 90 strips each. To ensure a seamless fit of these strips, several radiometric and geometric corrections are applied in the photogrammetric process. A simultaneous bundle adjustment of all strips as a block is carried out to estimate their precise exterior orientation. Because size, position, resolution and image quality of the strips in these blocks are heterogeneous, also the quality and distribution of the tie points vary. In absence of ground control points, heights of a global terrain model are used as reference information, and for this task a regular distribution of these tie points is preferable. Besides, their total number should be limited because of computational reasons. In this paper, we present an algorithm, which optimizes the distribution of tie points under these constraints. A large number of tie points used as input is reduced without affecting the geometric stability of the block by preserving connections between strips. This stability is achieved by using a regular grid in object space and discarding, for each grid cell, points which are redundant for the block adjustment. The set of tie points, filtered by the algorithm, shows a more homogenous distribution and is considerably smaller. Used for the block adjustment, it yields results of equal quality, with significantly shorter computation time. In this work, we present experiments with MC-30 half-tile blocks, which confirm our idea for reaching a stable and faster bundle adjustment. The described method is used for the systematic processing of HRSC data.

Improving proton conduction pathways in di- and triblock copolymer membranes: Branched versus linear side chains

NASA Astrophysics Data System (ADS)

Dorenbos, G.

2017-06-01

Phase separation within a series of polymer membranes in the presence of water is studied by dissipative particle dynamics. Each polymer contains hydrophobic A beads and hydrophilic C beads. Three parent architectures are constructed from a backbone composed of connected hydrophobic A beads to which short ([C]), long ([A3C]), or symmetrically branched A5[AC][AC] side chains spring off. Three di-block copolymer derivatives are constructed by covalently bonding an A30 block to each parent architecture. Also three tri-blocks with A15 blocks attached to both ends of each parent architecture are modeled. Monte Carlo tracer diffusion calculations through the water containing pores for 1226 morphologies reveal that water diffusion for parent architectures is slowest and diffusion through the di-blocks is fastest. Furthermore, diffusion increases with side chain length and is highest for branched side chains. This is explained by the increase of water pore size with , which is the average number of bonds that A beads are separated from a nearest C bead. Optimization of within the amphiphilic parent architecture is expected to be essential in improving proton conduction in polymer electrolyte membranes.

Self calibration of the stereo vision system of the Chang'e-3 lunar rover based on the bundle block adjustment

NASA Astrophysics Data System (ADS)

Zhang, Shuo; Liu, Shaochuang; Ma, Youqing; Qi, Chen; Ma, Hao; Yang, Huan

2017-06-01

The Chang'e-3 was the first lunar soft landing probe of China. It was composed of the lander and the lunar rover. The Chang'e-3 successful landed in the northwest of the Mare Imbrium in December 14, 2013. The lunar rover completed the movement, imaging and geological survey after landing. The lunar rover equipped with a stereo vision system which was made up of the Navcam system, the mast mechanism and the inertial measurement unit (IMU). The Navcam system composed of two cameras with the fixed focal length. The mast mechanism was a robot with three revolute joints. The stereo vision system was used to determine the position of the lunar rover, generate the digital elevation models (DEM) of the surrounding region and plan the moving paths of the lunar rover. The stereo vision system must be calibrated before use. The control field could be built to calibrate the stereo vision system in the laboratory on the earth. However, the parameters of the stereo vision system would change after the launch, the orbital changes, the braking and the landing. Therefore, the stereo vision system should be self calibrated on the moon. An integrated self calibration method based on the bundle block adjustment is proposed in this paper. The bundle block adjustment uses each bundle of ray as the basic adjustment unit and the adjustment is implemented in the whole photogrammetric region. The stereo vision system can be self calibrated with the proposed method under the unknown lunar environment and all parameters can be estimated simultaneously. The experiment was conducted in the ground lunar simulation field. The proposed method was compared with other methods such as the CAHVOR method, the vanishing point method, the Denavit-Hartenberg method, the factorization method and the weighted least-squares method. The analyzed result proved that the accuracy of the proposed method was superior to those of other methods. Finally, the proposed method was practical used to self calibrate the stereo vision system of the Chang'e-3 lunar rover on the moon.

Fiber tracking of brain white matter based on graph theory.

PubMed

Lu, Meng

2015-01-01

Brain white matter tractography is reconstructed via diffusion-weighted magnetic resonance images. Due to the complex structure of brain white matter fiber bundles, fiber crossing and fiber branching are abundant in human brain. And regular methods with diffusion tensor imaging (DTI) can't accurately handle this problem. the biggest problems of the brain tractography. Therefore, this paper presented a novel brain white matter tractography method based on graph theory, so the fiber tracking between two voxels is transformed into locating the shortest path in a graph. Besides, the presented method uses Q-ball imaging (QBI) as the source data instead of DTI, because QBI can provide accurate information about multiple fiber crossing and branching in one voxel using orientation distribution function (ODF). Experiments showed that the presented method can accurately handle the problem of brain white matter fiber crossing and branching, and reconstruct brain tractograhpy both in phantom data and real brain data.

Brain white matter fiber estimation and tractography using Q-ball imaging and Bayesian MODEL.

PubMed

Lu, Meng

2015-01-01

Diffusion tensor imaging allows for the non-invasive in vivo mapping of the brain tractography. However, fiber bundles have complex structures such as fiber crossings, fiber branchings and fibers with large curvatures that tensor imaging (DTI) cannot accurately handle. This study presents a novel brain white matter tractography method using Q-ball imaging as the data source instead of DTI, because QBI can provide accurate information about multiple fiber crossings and branchings in a single voxel using an orientation distribution function (ODF). The presented method also uses graph theory to construct the Bayesian model-based graph, so that the fiber tracking between two voxels can be represented as the shortest path in a graph. Our experiment showed that our new method can accurately handle brain white matter fiber crossings and branchings, and reconstruct brain tractograhpy both in phantom data and real brain data.

Trypanosoma cruzi infection and electrocardiographic findings among active manual workers. A population-based study in central Brazil.

PubMed

Zicker, F; Netto, J C; Zicker, E M; Oliveira, R M; Smith, P G

1990-03-01

In a cross sectional survey of the prevalence of Trypanosoma cruzi infection among urban unskilled workers in Goiânia, Brazil, blood samples from 6222 manual workers from seven institutions were examined for anti-Trypanosoma cruzi antibodies by immunofluorescence, ELISA and haemagglutination tests. ECGs were performed and a clinical history was taken from 624 seropositive and a random sample of 529 seronegative subjects. Abnormal ECGs were found in 15.1% of individuals without Trypanosoma cruzi antibodies and in 44.4% of those with antibodies (p less than 0.001). In general, cardiovascular symptoms reported were not associated with seropositivity nor with ECG alterations but dizziness and dyspnoea were more often reported among those with an abnormal tracing (p less than 0.01). The prevalence of ECG abnormalities increased with age in both groups but was higher among those seropositive in all age groups. An odds ratio of 2.0 (95% Cl 1.2-3.1) and 2.9 (95% Cl 1.5-6.3) of ECG abnormalities, for each decade of life, was estimated for seropositive and seronegative subjects, respectively. Relative risks (based on the odds ratios) for various specific ECG abnormalities, comparing seropositive to seronegative individuals, were calculated after adjustment for age, sex and institution. The odds ratio for complete right bundle branch block was 49.9 (95% CL 12.2-203.4); for left anterior hemiblock was 4.1 (2.8-6.0); for large Q/QS waves was 4.2 (2.4-7.3) and for first degree A-V block was 8.5 (2.6-28.1).

Kinetically controlled transition from disordered aggregates to ordered lattices of a computationally designed peptide sequence.

NASA Astrophysics Data System (ADS)

Tian, Yu; Zhang, Huixi; Kiick, Kristi; Saven, Jeffrey; Pochan, Darrin

Peptides with well-defined secondary-structures have the ability to exhibit specific, local shapes, which enables the design of complex nanostructures through intermolecular assembly. Our computationally designed coiled-coil homotetrameric peptide building block can self-assemble into 2-D nanomaterial lattices with predetermined symmetries by control of the coiled-coil bundle exterior amino acid residues. And the assemblies can be controlled kinetically. Firstly, the solution pH influences the assembly by affecting the external charged state of peptide bundles which can lead the bundles to be either repulsive or attractive to each other. At room temperature when peptides are under the least charged pH conditions, disordered aggregates are formed that slowly transformed into the desired 2-D lattice structures over long periods of time (weeks). Around neutral pH, even subtle charge differences that come from small pH changes can have an influence on the thickness of afterwards formed plates. Secondly, the solution temperature can largely eliminate the formation of disordered aggregates and accelerate the assembling of matured, desired nanomaterial plates by providing extra energy for the organization process of assembly building blocks. The ability to control the assembly process kinetically makes our peptide plate assemblies very promising templates for further applications to develop inorganic-organic hybrid materials. Funding acknowledged from NSF DMREF program under awards DMR-1234161 and DMR-1235084.

Communicating branches between lingual and hypoglossal nerve: observation using Sihler's staining technique.

PubMed

Iwanaga, Joe; Watanabe, Koichi; Saga, Tsuyoshi; Tabira, Yoko; Nakamura, Moriyoshi; Fisahn, Christian; Tubbs, R Shane; Kusukawa, Jingo; Yamaki, Koh-Ichi

2017-07-01

Many dental procedures are at risk of injuring the lingual nerve. We performed this study to better elucidate the microanatomy that exists between the ipsilateral lingual and hypoglossal nerves so that iatrogenic injury can be avoided. Adult human cadaveric tongues (ten sides) underwent Sihler's staining to identify the microanatomy between the lingual and hypoglossal nerves. The lingual nerve entered the middle part of the anterior two-thirds of the tongue from its lateral side and divided into two to four thick branches. These branches were then disseminated to the anterior, middle, and posterior parts of the anterior two-thirds of the tongue via 7-14 thin nerve bundles as terminal branches. The hypoglossal nerve entered the tongue at the posterior border of its anterior two-thirds and traveled forward to the apex of the tongue on all sides. All specimens were found to have communicating branches between the lingual and hypoglossal nerves at its anterior, middle, and posterior thirds. Our results indicate that the ipsilateral lingual and hypoglossal nerves constantly have three connections on each side between them. This knowledge might aid the dentist in minimizing iatrogenic nerve injury.

Exploring endoperoxides as a new entry for the synthesis of branched azasugars

PubMed Central

Domeyer, Svenja; Bjerregaard, Mark; Johansson, Henrik

2017-01-01

A new class of nitrogen-containing endoperoxides were synthesised by a photochemical [4 + 2]-cycloaddition between a diene and singlet oxygen. The endoperoxides were dihydroxylated and protected to provide a series of endoperoxide building blocks for organic synthesis, with potential use as precursors for the synthesis of branched azasugars. Preliminary exploration of the chemistry of these building blocks provided access to a variety of derivatives including tetrahydrofurans, epoxides and protected amino-tetraols. PMID:28487758

Heart Block

MedlinePlus

... to begin a new heartbeat 60 to 100 times a minute. From the SA node, the signal travels through the right and left atria. This causes ... AV node. This slowing allows the ventricles enough time to finish filling with ... leaves the AV node and travels along a pathway called the bundle of His. ...

[Ultrasound-assisted approach to blocking the intercostal nerves in the mid-axillary line for non-reconstructive breast and axilla surgery].

PubMed

Diéguez García, P; Fajardo Pérez, M; López Álvarez, S; Alfaro de la Torre, P; Pensado Castiñeiras, A P

2013-01-01

Several nerve blocks have recently been used for pain treatment in breast surgery. The main objective of our study was to determine the efficacy and safety of ultrasound-assisted blocking of the anterior and lateral cutaneous branches of the intercostal nerves in the mid-axillary line for non-reconstructive breast and axilla surgery. A prospective observational study was conducted on 30 patients scheduled for non-reconstructive breast and axilla surgery. An intercostal branches block was performed in the mid-axillary line with 0,5% levobupivacaine (3ml in each intercostal space). Clinical efficacy was assessed by standard intraoperative hemodynamic response to surgical stimulus and the need for opioids, and in the postoperative period, by assessing pain intensity as a verbal numerical scale and the need for rescue treatment. We also evaluated the quality of sleep the first night after surgery, any adverse events that occurred, and the satisfaction of patients and surgeons with the anesthetic technique. The intercostal branches block in the mid-axillary line was effective in most cases, with only 2 patients requiring intraoperative opioids, and in one case analgesic rescue was necessary in the postoperative period. The duration of postoperative analgesia was 19±4h. There were no notable adverse events or complications. The satisfaction with the chosen technique was assessed as "very good" in all patients, and by 97% of the surgeons. Intercostal branches block in the mid-axillary line provides adequate intraoperative and postoperative analgesia for non-reconstructive breast and axilla surgery. It is a simple, reproducible technique in most patients of this study, with an easy to understand ultrasound anatomy, in which adequate analgesia could be provided through a single puncture, and may be an alternative to neuroaxial blocks. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Controlled growth of novel hyper-branched nanostructures in nanoporous alumina membrane.

PubMed

Zhang, Junping; Day, Cynthia S; Carroll, David L

2009-12-07

This paper proposes a novel approach to fabricate hyper-branched anodic aluminium oxide (AAO) nanostructures with different branches on the vertically-aligned trunk and at the trunk terminal. Silver nanowires with different dimensional and multifunctional complexity have been prepared from this hyper-branched AAO template by varying the electrodeposition time. These kinds of novel nanostructure may be used to build blocks for nanoelectronic and nanophotonic devices.

Elastic deformation and failure in protein filament bundles: Atomistic simulations and coarse-grained modeling.

PubMed

Hammond, Nathan A; Kamm, Roger D

2008-07-01

The synthetic peptide RAD16-II has shown promise in tissue engineering and drug delivery. It has been studied as a vehicle for cell delivery and controlled release of IGF-1 to repair infarcted cardiac tissue, and as a scaffold to promote capillary formation for an in vitro model of angiogenesis. The structure of RAD16-II is hierarchical, with monomers forming long beta-sheets that pair together to form filaments; filaments form bundles approximately 30-60 nm in diameter; branching networks of filament bundles form macroscopic gels. We investigate the mechanics of shearing between the two beta-sheets constituting one filament, and between cohered filaments of RAD16-II. This shear loading is found in filament bundle bending or in tensile loading of fibers composed of partial-length filaments. Molecular dynamics simulations show that time to failure is a stochastic function of applied shear stress, and that for a given loading time behavior is elastic for sufficiently small shear loads. We propose a coarse-grained model based on Langevin dynamics that matches molecular dynamics results and facilities extending simulations in space and time. The model treats a filament as an elastic string of particles, each having potential energy that is a periodic function of its position relative to the neighboring filament. With insight from these simulations, we discuss strategies for strengthening RAD16-II and similar materials.

Active Coupled Oscillators in the Inner Ear

NASA Astrophysics Data System (ADS)

Strimbu, Clark Elliott

Auditory and vestibular systems are endowed with an active process that enables them to detect signals as small as a few Angstroms; they also exhibit frequency selectivity; show strong nonlinearities; and can exhibit as spontaneous activity. Much of this active process comes from the sensory hair cells at the periphery of the auditory and vestibular systems. Each hair cell is capped by an eponymous hair bundle, a specialized structure that transduces mechanical forces into electrical signals. Experiments on mechanically decoupled cells from the frog sacculus have shown that individual hair bundles behave in an active manner analogous to an intact organ suggesting a common cellular basis for the active processes seen in many species. In particular, mechanically decoupled hair bundles show rapid active movements in response to transient stimuli and exhibit spontaneous oscillations. However, a single mechanosensitive hair cell is unable to match the performance of an entire organ. In vivo, hair bundles are often coupled to overlying membranes, gelatinous extracellular matrices. We used an in vitro preparation of the frog sacculus in which the otolithic membrane has been left intact. Under natural coupling conditions, there is a strong degree of correlation across the saccular epithelium, suggesting that the collective response of many cells contributes to the extreme sensitivity of this organ. When the membrane is left intact, the hair bundles do not oscillate spontaneously, showing that the natural coupling and loading tunes them into a quiescent regime. However, when stimulated by a pulse, the bundles show a rapid biphasic response that is abolished when the transduction channels are blocked. The active forces generated by the bundles are sufficient to move the overlying membrane.

Colloidal polymers with controlled sequence and branching constructed from magnetic field assembled nanoparticles.

PubMed

Bannwarth, Markus B; Utech, Stefanie; Ebert, Sandro; Weitz, David A; Crespy, Daniel; Landfester, Katharina

2015-03-24

The assembly of nanoparticles into polymer-like architectures is challenging and usually requires highly defined colloidal building blocks. Here, we show that the broad size-distribution of a simple dispersion of magnetic nanocolloids can be exploited to obtain various polymer-like architectures. The particles are assembled under an external magnetic field and permanently linked by thermal sintering. The remarkable variety of polymer-analogue architectures that arises from this simple process ranges from statistical and block copolymer-like sequencing to branched chains and networks. This library of architectures can be realized by controlling the sequencing of the particles and the junction points via a size-dependent self-assembly of the single building blocks.

Two-dimensional periodic texture of actin filaments formed upon drying

PubMed Central

Honda, Hajime; Ishiwata, Shin’ichi

2011-01-01

We found that a solution of actin filaments can form a periodic texture in the process of drying on a flat glass surface in the air; the periodic texture was composed of smooth meandering bundles of actin filaments. We also found that a branched salt crystal grows in the space between the meandering bundles of actin filaments. The distance between the adjacent striae (striation period) in the resulting dried two-dimensional pattern of striation decreased from about 50 to 2 μm, as the ambient temperature was increased from 4 to 40°C at 1 mg/ml actin, and showed an increasing tendency from a few to several tens μm with the increase in the initial concentration of actin filaments from 0.6 to 2.0mg/ml at room temperature. As the speed of drying is increased at a certain temperature, the striation period was also found to decrease. We propose that the formation of the two-dimensional striation pattern of bundles of actin filaments is the result of condensation of proteins due to dehydration, and suggest that the solvent flow from the center to the periphery of the sample causes the meandering of actin filaments. PMID:27857588

Diagnosis and management of ST elevation myocardial infarction: a review of the recent literature and practice guidelines.

PubMed

Hahn, Sigrid A; Chandler, Charles

2006-01-01

There is a large volume of literature available to guide the peri-infarct management of ST elevation myocardial infarction (STEMI). Most of this literature focuses on improving the availability and efficacy of reperfusion therapy. The purpose of this article is to review contemporary scientific evidence and guideline recommendations regarding the diagnosis and therapy of STEMI. Studies and epidemiological data were identified using Medline, the Cochrane Database, and an Internet search engine. Medline was searched for landmark and recent publications using the following key words: STEMI, guidelines, epidemiology, reperfusion, fibrinolytics, percutaneous coronary intervention (PCI), facilitated PCI, transfer, delay, clopidogrel, glycoprotein IIb/IIIa, low-molecular-weight heparin (LMWH), beta-blockers, nitrates, and angiotensin-converting enzyme (ACE) inhibitors. The data accessed indicate that urgent reperfusion with either fibrinolytics or percutaneous intervention should be considered for every patient having symptoms of myocardial infarction with ST segment elevation or a bundle branch block. The utility of combined mechanical and pharmacological reperfusion is currently under investigation. Ancillary treatments may utilize clopidogrel, glycoprotein IIb/IIIa inhibitors, or low molecular weight heparin, depending on the primary reperfusion strategy used. Comprehensive clinical practice guidelines incorporate much of the available contemporary evidence, and are important resources for the evidence-based management of STEMI.

[Arrhythmogenic right ventricular cardiomyopathy. Case report and a brief literature review].

PubMed

Izurieta, Carlos; Curotto-Grasiosi, Jorge; Rocchinotti, Mónica; Torres, María J; Moranchel, Manuel; Cañas, Sebastián; Cardús, Marta E; Alasia, Diego; Cordero, Diego J; Angel, Adriana

2013-01-01

A 51-year-old man was admitted to this hospital because of palpitations and a feeling of dizziness for a period of 2h. The electrocardiogram revealed a regular wide-QRS complex tachycardia at a rate of 250 beats per minute, with superior axis and left bundle branch block morphology without hemodynamically decompensation, the patient was cardioverted to sinus rhythm after the administration of a loading and maintenance dose of amiodarone. The elechtrophysiological study showed the ventricular origin of the arrhythmia. In order to diagnose the etiology of the ventricular tachycardia we performed a coronary arteriography that showed normal epicardial vessels, thus ruling out coronary disease. Doppler echocardiography revealed systolic and diastolic functions of both left and right ventricles within normal parameters, and normal diameters as well. A cardiac magnetic resonance with late enhancement was done, showing structural abnormalities of the right ventricle wall with moderate impairment of the ejection fraction, and a mild dysfunction of the left ventricle. The diagnosis of arrhythmogenic right ventricular cardiomyopathy was performed as 2 major Task Force criteria were met. We implanted an automatic cardioverter defibrillator as a prophylactic measure. The patient was discharged without complications. Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Extreme Right Axis Deviation in Acute Myocardial Infarction: A Hazardous Signal of Poor Prognosis.

PubMed

Wang, Qingyu; Pan, Shuo; Liu, Fuqiang; Yang, Dan; Wang, Jun-Kui

2018-05-11

BACKGROUND New-onset extreme right axis deviation and right bundle branch block (RBBB) are rare during acute myocardial infarction (AMI), and has only been reported in several cases reflecting the severity of AMI. It could predict severe clinical complications and higher risks in coronary artery disease. Although there is little electrophysiological explanation, the complications are severe. They should be emphasized in newly diagnosed extreme right axis deviation and RBBB in AMI. CASE REPORT A 72-year-old male was admitted to our department with a chief complaint of intermittent retrosternal chest pain and was diagnosed with extensive anterior myocardial infarction with RBBB, by elevated myocardial enzymes and ECG. The main wave direction of QRS in lead aVR was positive and showed an extreme right axis deviation. After a month, the patient's chest distress and the RBBB vanished, but a right axis deviation still existed. The echocardiogram showed prior extensive anterior myocardial infarction (including apex myocardia) and lower LVEF. CONCLUSIONS New diagnosed RBBB and right axis deviation is uncommon and could be a useful clue to evaluate myocardial ischemia in AMI cases. This electrocardiographic marker can identify coronary artery occlusion where ST-segments are hard to evaluate, and hence, patients may benefit most from early and complete revascularization strategies such as primary angioplasty.

31 CFR 586.519 - Release of certain funds held at overseas branches of U.S. financial institutions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... overseas branches of U.S. financial institutions. 586.519 Section 586.519 Money and Finance: Treasury... of U.S. financial institutions. Specific licenses may be issued on a case-by-case basis to permit the overseas branches of U.S. financial institutions to unblock deposit accounts that were blocked pursuant to...

Diversity in the organization of elastin bundles and intramembranous muscles in bat wings.

PubMed

Cheney, Jorn A; Allen, Justine J; Swartz, Sharon M

2017-04-01

Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology. We characterized the plagiopatagium and dactylopatagium of 130 species from 17 families of bats using cross-polarized light imaging. This method revealed structures with distinctive relative birefringence, heterogeneity of birefringence, variation in size, and degree of branching. We used previously published anatomical studies and tissue histology to identify birefringent structures, and we analyzed their architecture across taxa. Elastin bundles, muscles, neurovasculature, and collagenous fibers are present in all species. Elastin bundles are oriented in a predominantly spanwise or proximodistal direction, and there are five characteristic muscle arrays that occur within the plagiopatagium, far more muscle than typically recognized. These results inform recent functional studies of wing membrane architecture, support the functional hypothesis that elastin bundles aid wing folding and unfolding, and further suggest that all bats may use these architectural elements for flight. All species also possess numerous muscles within the wing membrane, but the architecture of muscle arrays within the plagiopatagium varies among families. To facilitate present and future discussion of these muscle arrays, we refine wing membrane muscle nomenclature in a manner that reflects this morphological diversity. The architecture of the constituents of the skin of the wing likely plays a key role in shaping wings during flight. © 2017 Anatomical Society.

From proto-Kranz to C4 Kranz: building the bridge to C4 photosynthesis.

PubMed

Sage, Rowan F; Khoshravesh, Roxana; Sage, Tammy L

2014-07-01

In this review, we examine how the specialized "Kranz" anatomy of C4 photosynthesis evolved from C3 ancestors. Kranz anatomy refers to the wreath-like structural traits that compartmentalize the biochemistry of C4 photosynthesis and enables the concentration of CO2 around Rubisco. A simplified version of Kranz anatomy is also present in the species that utilize C2 photosynthesis, where a photorespiratory glycine shuttle concentrates CO2 into an inner bundle-sheath-like compartment surrounding the vascular tissue. C2 Kranz is considered to be an intermediate stage in the evolutionary development of C4 Kranz, based on the intermediate branching position of C2 species in 14 evolutionary lineages of C4 photosynthesis. In the best-supported model of C4 evolution, Kranz anatomy in C2 species evolved from C3 ancestors with enlarged bundle sheath cells and high vein density. Four independent lineages have been identified where C3 sister species of C2 plants exhibit an increase in organelle numbers in the bundle sheath and enlarged bundle sheath cells. Notably, in all of these species, there is a pronounced shift of mitochondria to the inner bundle sheath wall, forming an incipient version of the C2 type of Kranz anatomy. This incipient version of C2 Kranz anatomy is termed proto-Kranz, and is proposed to scavenge photorespiratory CO2. By doing so, it may provide fitness benefits in hot environments, and thus represent a critical first stage of the evolution of both the C2 and C4 forms of Kranz anatomy. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Transection versus preservation of the neurovascular bundle of the lesser omentum in primary Roux-en-Y gastric bypass surgery.

PubMed

van Wezenbeek, Martin R; van Oudheusden, Thijs R; Smulders, J Frans; Nienhuijs, Simon W; Luyer, Misha D

2016-02-01

A gastric pouch in Roux-en-Y gastric bypass (RYGB) surgery can be created after transection of the perigastric neurovascular bundle or by preserving these structures. Some surgeons choose to transect the neurovascular bundle (NBT), containing branches of the vagus nerve, because this might be related to additional weight loss, whereas others advocate preservation (NBP) to reduce postoperative complications. This study assessed the effect of both techniques after primary RYGB. All patients undergoing primary RYGB in a large bariatric center in the Netherlands between January 2010 and December 2013 were included. Patient demographic characteristics, operative details, postoperative complications and weight loss after 1 year were retrospectively analyzed. A total of 773 consecutive patients were included (85.5% female). NBT was performed in 407 patients (52.7%), whereas NBP was performed in 366 patients. There were no missing data and 81.2% of patients completed the 1-year follow-up. Postoperative complications were found in 66 patients (8.5%). A total of 49 patients (6.3%) either had an anastomotic leakage, postoperative bleeding, or intraabdominal abscess (NBT 8.8% versus NBP 3.6%, P = .003). Percentage total weight loss (NBT 34.5%±6.9% versus NBP 33.4%±6.9%; P = .011) differed to a lesser extent between groups, although this was significant. Neurovascular bundle transection was identified as independent factor among others for occurrence of leakage, bleeding, and abscess development (OR 2.886; 95% CI [1.466-5.683]; P = .002). Transection of the neurovascular bundle in RYGB is associated with more complications. Furthermore, weight loss is not relevantly increased. Further research is necessitated to substantiate these findings. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Relevance of Conduction Disorders in Bachmann's Bundle During Sinus Rhythm in Humans.

PubMed

Teuwen, Christophe P; Yaksh, Ameeta; Lanters, Eva A H; Kik, Charles; van der Does, Lisette J M E; Knops, Paul; Taverne, Yannick J H J; van de Woestijne, Pieter C; Oei, Frans B S; Bekkers, Jos A; Bogers, Ad J J C; Allessie, Maurits A; de Groot, Natasja M S

2016-05-01

Bachmann's bundle (BB) is considered to be the main route of interatrial conduction and to play a role in development of atrial fibrillation (AF). The goals of this study are to characterize the presence of conduction disorders in BB during sinus rhythm and to study their relation with AF. High-resolution epicardial mapping (192 unipolar electrodes, interelectrode distance: 2 mm) of sinus rhythm was performed in 185 patients during coronary artery bypass surgery of whom 13 had a history of paroxysmal AF. Continuous rhythm monitoring was used to detect postoperative AF during the first 5 postoperative days. In 67% of the patients, BB was activated from right to left; in the remaining patients from right and middle (21%), right, central, and left (8%), or central (4%) site. Mean effective conduction velocity was 89 cm/s. Conduction block was present in most patients (75%; median 1.1%, range 0-12.8) and was higher in patients with paroxysmal AF compared with patients without a history of AF (3.2% versus 0.9%; P=0.03). A high amount of conduction block (>4%) was associated with de novo postoperative AF (P=0.02). Longitudinal lines of conduction block >10 mm were also associated with postoperative AF (P=0.04). BB may be activated through multiple directions, but the predominant route of conduction is from right to left. Conduction velocity across BB is around 90 cm/s. Conduction is blocked in both longitudinal and transverse direction in the majority of patients. Conduction disorders, particularly long lines of longitudinal conduction block, are more pronounced in patients with AF episodes. © 2016 American Heart Association, Inc.

SDF1 Reduces Interneuron Leading Process Branching through Dual Regulation of Actin and Microtubules

PubMed Central

Lysko, Daniel E.; Putt, Mary

2014-01-01

Normal cerebral cortical function requires a highly ordered balance between projection neurons and interneurons. During development these two neuronal populations migrate from distinct progenitor zones to form the cerebral cortex, with interneurons originating in the more distant ganglionic eminences. Moreover, deficits in interneurons have been linked to a variety of neurodevelopmental disorders underscoring the importance of understanding interneuron development and function. We, and others, have identified SDF1 signaling as one important modulator of interneuron migration speed and leading process branching behavior in mice, although how SDF1 signaling impacts these behaviors remains unknown. We previously found SDF1 inhibited leading process branching while increasing the rate of migration. We have now mechanistically linked SDF1 modulation of leading process branching behavior to a dual regulation of both actin and microtubule organization. We find SDF1 consolidates actin at the leading process tip by de-repressing calpain protease and increasing proteolysis of branched-actin-supporting cortactin. Additionally, SDF1 stabilizes the microtubule array in the leading process through activation of the microtubule-associated protein doublecortin (DCX). DCX stabilizes the microtubule array by bundling microtubules within the leading process, reducing branching. These data provide mechanistic insight into the regulation of interneuron leading process dynamics during neuronal migration in mice and provides insight into how cortactin and DCX, a known human neuronal migration disorder gene, participate in this process. PMID:24695713

Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma).

PubMed

Liu, Alexander G; Matthews, Jack J; Menon, Latha R; McIlroy, Duncan; Brasier, Martin D

2014-10-22

Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized muscular tissue before the Early Cambrian has hitherto remained moot, being reliant upon indirect evidence in the form of Late Ediacaran ichnofossils. We here report a candidate muscle-bearing organism, Haootia quadriformis n. gen., n. sp., from approximately 560 Ma strata in Newfoundland, Canada. This taxon exhibits sediment moulds of twisted, superimposed fibrous bundles arranged quadrilaterally, extending into four prominent bifurcating corner branches. Haootia is distinct from all previously published contemporaneous Ediacaran macrofossils in its symmetrically fibrous, rather than frondose, architecture. Its bundled fibres, morphology, and taphonomy compare well with the muscle fibres of fossil and extant Cnidaria, particularly the benthic Staurozoa. Haootia quadriformis thus potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record.

Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma)

PubMed Central

Liu, Alexander G.; Matthews, Jack J.; Menon, Latha R.; McIlroy, Duncan; Brasier, Martin D.

2014-01-01

Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized muscular tissue before the Early Cambrian has hitherto remained moot, being reliant upon indirect evidence in the form of Late Ediacaran ichnofossils. We here report a candidate muscle-bearing organism, Haootia quadriformis n. gen., n. sp., from approximately 560 Ma strata in Newfoundland, Canada. This taxon exhibits sediment moulds of twisted, superimposed fibrous bundles arranged quadrilaterally, extending into four prominent bifurcating corner branches. Haootia is distinct from all previously published contemporaneous Ediacaran macrofossils in its symmetrically fibrous, rather than frondose, architecture. Its bundled fibres, morphology, and taphonomy compare well with the muscle fibres of fossil and extant Cnidaria, particularly the benthic Staurozoa. Haootia quadriformis thus potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record. PMID:25165764

An efficient mechanism for enhancing the thermoelectricity of nanoribbons by blocking phonon transport in 2D materials.

PubMed

Liu, Yue-Yang; Zeng, Yu-Jia; Jia, Pin-Zhen; Cao, Xuan-Hao; Jiang, Xiangwei; Chen, Ke-Qiu

2018-07-11

Inspired by the novel mechanism of reducing thermal conductivity by local phonon resonance instead of by inducing structural defects, we investigate the effect of side branching on the thermoelectric properties of [Formula: see text] nanoribbons, and prove that side branching is a highly efficient mechanism for enhancing the thermoelectricity of different kinds of nanoribbons. For both armchair and zigzag [Formula: see text] nanoribbons, the side branches result in not only significant blocking of phonon transport but also notable increase of the Seebeck coefficient. Consequently, the thermoelectric figure of merit of the armchair [Formula: see text] nanoribbon is boosted from 0.72 to as high as 1.93, and the originally non-thermoelectric metallic zigzag [Formula: see text] nanoribbon is turned into a thermoelectric material due to the appearance of the band gap induced by the side branches. These results mean that the mechanism of branching is not only very efficient, but also takes effect regardless of the original properties of the nanoribbons, and thus will hold great promise for its application in the thermoelectric field.

21 CFR 886.1250 - Euthyscope.

Code of Federal Regulations, 2011 CFR

2011-04-01

... inspect the interior of the eye) that projects a bright light encompassing an arc of about 30 degrees onto the fundus of the eye. The center of the light bundle is blocked by a black disk covering the fovea... disease of the eye). (b) Classification. Class I for the battery powered device. The battery powered...

21 CFR 886.1250 - Euthyscope.

Code of Federal Regulations, 2010 CFR

2010-04-01

... inspect the interior of the eye) that projects a bright light encompassing an arc of about 30 degrees onto the fundus of the eye. The center of the light bundle is blocked by a black disk covering the fovea... disease of the eye). (b) Classification. Class I for the battery powered device. The battery powered...

Combining living anionic polymerization with branching reactions in an iterative fashion to design branched polymers.

PubMed

Higashihara, Tomoya; Sugiyama, Kenji; Yoo, Hee-Soo; Hayashi, Mayumi; Hirao, Akira

2010-06-16

This paper reviews the precise synthesis of many-armed and multi-compositional star-branched polymers, exact graft (co)polymers, and structurally well-defined dendrimer-like star-branched polymers, which are synthetically difficult, by a commonly-featured iterative methodology combining living anionic polymerization with branched reactions to design branched polymers. The methodology basically involves only two synthetic steps; (a) preparation of a polymeric building block corresponding to each branched polymer and (b) connection of the resulting building unit to another unit. The synthetic steps were repeated in a stepwise fashion several times to successively synthesize a series of well-defined target branched polymers. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An exploration of the reflow technique for the fabrication of an in vitro microvascular system to study occlusive clots.

PubMed

Li, Yang; Pan, Chuer; Li, Yunfeng; Kumacheva, Eugenia; Ramachandran, Arun

2017-09-08

Embolic ischemia and pulmonary embolism are health emergencies that arise when a particle such as a blood clot occludes a smaller blood vessel in the brain or the lungs, and restricts flow of blood downstream of the vessel. In this work, the reflow technique (Wang et al. Biomed. Microdevices 2007, 9, 657) was adapted to produce a microchannel network that mimics the occlusion process. The technique was first revisited and a simple geometrical model was developed to quantitatively explain the shapes of the resulting microchannels for different reflow parameters. A critical modification was introduced to the reflow protocol to fabricate nearly circular microchannels of different diameters from the same master, which is not possible with the traditional reflow technique. To simulate the phenomenon of occlusion by clots, a microchannel network with three generations of branches with different diameters and branching angles was fabricated, into which fibrin clots were introduced. At low constant pressure drop (ΔP), a clot blocked a branch entrance only partially, while at higher ΔP, the branch was completely blocked. Instances of simultaneous blocking of multiple channels by clots, and the consequent changes in the flow rates in the unblocked branches of the network, were also monitored. This work provides the framework for a systematic study of the distribution of clots in a network, and the rate of dissolution of embolic clots upon the introduction of a thrombolytic drug into the network.

Noninvasive, automatic optimization strategy in cardiac resynchronization therapy.

PubMed

Reumann, Matthias; Osswald, Brigitte; Doessel, Olaf

2007-07-01

Optimization of cardiac resynchronization therapy (CRT) is still unsolved. It has been shown that optimal electrode position,atrioventricular (AV) and interventricular (VV) delays improve the success of CRT and reduce the number of non-responders. However, no automatic, noninvasive optimization strategy exists to date. Cardiac resynchronization therapy was simulated on the Visible Man and a patient data-set including fiber orientation and ventricular heterogeneity. A cellular automaton was used for fast computation of ventricular excitation. An AV block and a left bundle branch block were simulated with 100%, 80% and 60% interventricular conduction velocity. A right apical and 12 left ventricular lead positions were set. Sequential optimization and optimization with the downhill simplex algorithm (DSA) were carried out. The minimal error between isochrones of the physiologic excitation and the therapy was computed automatically and leads to an optimal lead position and timing. Up to 1512 simulations were carried out per pathology per patient. One simulation took 4 minutes on an Apple Macintosh 2 GHz PowerPC G5. For each electrode pair an optimal pacemaker delay was found. The DSA reduced the number of simulations by an order of magnitude and the AV-delay and VV - delay were determined with a much higher resolution. The findings are well comparable with clinical studies. The presented computer model of CRT automatically evaluates an optimal lead position and AV-delay and VV-delay, which can be used to noninvasively plan an optimal therapy for an individual patient. The application of the DSA reduces the simulation time so that the strategy is suitable for pre-operative planning in clinical routine. Future work will focus on clinical evaluation of the computer models and integration of patient data for individualized therapy planning and optimization.

Perventricular double-device closure of wide-spaced multi-hole perimembranous ventricular septal defect.

PubMed

Liang, Fei; Hongxin, Li; Zhang, Hai-Zhou; Wenbin, Guo; Zou, Cheng-Wei; Farhaj, Zeeshan

2017-04-17

Device closure of a wide-spaced multi-hole PmVSD is difficult to succeed in percutaneous approach. This study is to evaluate the feasibility, safety and efficacy of perventricular device closure of wide-spaced multi-hole PmVSD using a double-device implanting technique. Sixteen patients with wide-spaced multi-hole PmVSD underwent perventricular closure with two devices through an inferior median sternotomy approach under transesophageal echocardiographic guidance. The largest hole and its adjacent small holes were occluded with an optimal-sized device. The far-away residual hole was occluded with the other device using a probe-assisted delivery system. All patients were followed up for a period of 1 to 4 years to determine the residual shunt, atrioventricular block and the adjacent valvular function. The number of the holes of the PmVSD was 2 to 4. The maximum distance between the holes was 5.0 to 10.0 mm (median, 6.4 mm). The diameter of the largest hole was 2.5 to 7.0 mm (median, 3.6 mm). The success rate of double-device closure was 100%. Immediate residual shunts were found in 6 patients (38%), and incomplete right bundle branch block at discharge occurred in 3 cases (19%). Both complications decreased to 6% at 1-year follow-up. Neither of them had a severe device-related complication. Perventricular closure of a wide-spaced multi-hole PmVSD using a double-device implanting technique is feasible, safe, and efficacious. In multi-hole PmVSDs with the distance between the holes of more than 5 mm, double-device implantation may achieve a complete occlusion.

Pacemaker dependency after transcatheter aortic valve implantation with the self-expanding Medtronic CoreValve System.

PubMed

van der Boon, Robert M A; Van Mieghem, Nicolas M; Theuns, Dominic A; Nuis, Rutger-Jan; Nauta, Sjoerd T; Serruys, Patrick W; Jordaens, Luc; van Domburg, Ron T; de Jaegere, Peter P T

2013-09-30

To determine pacemaker (PM) dependency at follow-up visit in patients who underwent new permanent pacemaker implantation (PPI) following transcatheter aortic valve implantation (TAVI). Single center prospective observational study including 167 patients without previous PM implantation who underwent TAVI with the self-expanding Medtronic CoreValve System (MCS) between November 2005 and February 2011. PM dependency was defined by the presence of a high degree atrioventricular block (HDAVB; second [AV2] and third degree [AV3B]), or a slow (<30 bpm) or absent ventricular escape rhythm during follow-up PM interrogation. A total of 36 patients (21.6%) received a new PM following TAVI. The indication for PM was AV2B (n=2, 5.6%), AV3B (n=28, 77.8%), postoperative symptomatic bradycardia (n=3, 8.3%), brady-tachy syndrome (n=1, 2.8%), atrial fibrilation with slow response (n=1, 2.8%) and left bundle branch block (n=1, 2.8%). Long term follow-up was complete for all patients and ranged from 1 to 40 months (median (IQR): 11.5 (5.0-18.0 months). Of those patients with a HDAVB, 16 out of the 30 patients (53.3%) were PM independent at follow-up visit (complete or partial resolution of the AV conduction abnormality). Overall, 20 out of the 36 patients (55.6%) who received a new PM following TAVI were PM independent at follow-up. Partial and even complete resolution of peri-operative AV conduction abnormalities after MCS valve implantation occurred in more than half of the patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

ST-Elevation myocardial infarction network: systematization in 205 cases reduced clinical events in the public health care system.

PubMed

Caluza, Ana Christina Vellozo; Barbosa, Adriano H; Gonçalves, Iran; Oliveira, Carlos Alexandre L de; Matos, Lívia Nascimento de; Zeefried, Claus; Moreno, Antonio Célio C; Tarkieltaub, Elcio; Alves, Cláudia Maria R; Carvalho, Antonio Carlos

2012-11-01

The major cause of death in the city of São Paulo (SP) is cardiac events. At its periphery, in-hospital mortality in acute myocardial infarction is estimated to range between 15% and 20% due to difficulties inherent in large metropoles. To describe in-hospital mortality in ST-segment elevation acute myocardial infarction (STEMI) of patients admitted via ambulance or peripheral hospitals, which are part of a structured training network (STEMI Network). Health care teams of four emergency services (Ermelino Matarazzo, Campo Limpo, Tatuapé and Saboya) of the periphery of the city of São Paulo and advanced ambulances of the Emergency Mobile Health Care Service (abbreviation in Portuguese, SAMU) were trained to use tenecteplase or to refer for primary angioplasty. A central office for electrocardiogram reading was used. After thrombolysis, the patient was sent to a tertiary reference hospital to undergo cardiac catheterization immediately (in case of failed thrombolysis) or in 6 to 24 hours, if the patient was stable. Quantitative and qualitative variables were assessed by use of uni- and multivariate analysis. From January 2010 to June 2011, 205 consecutive patients used the STEMI Network, and the findings were as follows: 87 anterior wall infarctions; 11 left bundle-branch blocks; 14 complete atrioventricular blocks; and 14 resuscitations after initial cardiorespiratory arrest. In-hospital mortality was 6.8% (14 patients), most of which due to cardiogenic shock, one hemorrhagic cerebrovascular accident, and one bleeding. The organization in the public health care system of a network for the treatment of STEMI, involving diagnosis, reperfusion, immediate transfer, and tertiary reference hospital, resulted in immediate improvement of STEMI outcomes.

Hypertrophic obstructive cardiomyopathy: the Mayo Clinic experience.

PubMed

Kotkar, Kunal D; Said, Sameh M; Dearani, Joseph A; Schaff, Hartzell V

2017-07-01

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disease characterized by left ventricular hypertrophy in the absence of other etiologies. Clinical presentation may vary from asymptomatic to sudden cardiac death. Medical treatment is the first-line therapy for symptomatic patients. Extended left ventricular septal myectomy is the procedure of choice if medical treatment is unsuccessful or intolerable. More than 3,000 patients have had septal myectomy for HCM at the Mayo Clinic (MN, USA) from 1993 to 2016. Risk of hospital death after isolated septal myectomy for obstructive HCM is <1% and is similar to the risk of operation for elective mitral valve repair. Complications, such as complete heart block requiring permanent pacemaker, are uncommon (2%), although partial or complete left bundle branch block is a frequent finding on the postoperative ECG. Relief of left ventricular outflow tract (LVOT) obstruction with septal myectomy dramatically improves symptoms and exercise capacity in symptomatic patients with obstructive HCM. More than 90% of severely symptomatic patients have improvement by at least two functional classes, and reduction of outflow gradients by myectomy decreases or eliminates symptoms of dyspnea, angina and/or syncope. Basal obstruction with systolic anterior motion (SAM) is treated by transaortic myectomy. The transapical approach was applied in 115 patients with obstructive midventricular and apical variants of HCM between 1993 and 2012. All patients with midventricular obstruction had gradient relief and none developed an apical aneurysm or ventricular septal defect. Recurrent obstruction after satisfactory myectomy was rare. Septal myectomy effectively and definitively relieves LVOT obstruction and cardiac symptoms in patients with obstructive HCM. In experienced centers, early mortality for isolated septal myectomy is less than 1%, and overall results are excellent and continue to improve in the current era.

Low permanent pacemaker rates following Lotus device implantation for transcatheter aortic valve replacement due to modified implantation protocol.

PubMed

Krackhardt, Florian; Kherad, Behrouz; Krisper, Maximilian; Pieske, Burkert; Laule, Michael; Tschöpe, Carsten

2017-01-01

Conduction disturbances requiring permanent pacemaker implantation following transcatheter aortic valve replacement (TAVR) are a common problem. Pacemaker implantation rates after TAVR appear to be higher compared to conventional aortic valve replacement. The aim of this study was to analyze whether a high annulus implantation conveys the benefit of a decreased rate of permanent pacemaker implantation while being safe and successful according to Valve Academic Research Consortium 2 (VARC2)-criteria. A total of 23 patients with symptomatic severe aortic valve stenosis, an aortic annulus of 19-27 mm and at high risk for surgery were treated with the Lotus valve. In all patients the valve was implanted in a high annulus position via femoral access. The primary device performance endpoint was VARC2-defined device success after 30 days and the primary safety endpoint was the need for permanent pacemaker implantation. The mean age was 73.23 ± 7.65 years, 46% were female, 38% were New York Heart Association class III/IV at baseline. Thirty-day follow-up data were available for all patients. The VARC2-defined device success rate after 30 days was 22/23 (96%). 2/21 (10%) patients required a newly implanted pacemaker due to 3rd degree atrioventricular block. 25% of the patients developed a new left bundle branch block after valvuloplasty or device implantation. 21 of the 23 patients (96%) had no other signs of conduction disturbances after 30 days. The approach of the modified implantation technique of Lotus TAVR device was safe and effective. The incidence of need for a permanent pacemaker following TAVR could be significantly reduced due to adopted implantation protocol.

Self-assembly of hierarchically ordered structures in DNA nanotube systems

NASA Astrophysics Data System (ADS)

Glaser, Martin; Schnauß, Jörg; Tschirner, Teresa; Schmidt, B. U. Sebastian; Moebius-Winkler, Maximilian; Käs, Josef A.; Smith, David M.

2016-05-01

The self-assembly of molecular and macromolecular building blocks into organized patterns is a complex process found in diverse systems over a wide range of size and time scales. The formation of star- or aster-like configurations, for example, is a common characteristic in solutions of polymers or other molecules containing multi-scaled, hierarchical assembly processes. This is a recurring phenomenon in numerous pattern-forming systems ranging from cellular constructs to solutions of ferromagnetic colloids or synthetic plastics. To date, however, it has not been possible to systematically parameterize structural properties of the constituent components in order to study their influence on assembled states. Here, we circumvent this limitation by using DNA nanotubes with programmable mechanical properties as our basic building blocks. A small set of DNA oligonucleotides can be chosen to hybridize into micron-length DNA nanotubes with a well-defined circumference and stiffness. The self-assembly of these nanotubes to hierarchically ordered structures is driven by depletion forces caused by the presence of polyethylene glycol. This trait allowed us to investigate self-assembly effects while maintaining a complete decoupling of density, self-association or bundling strength, and stiffness of the nanotubes. Our findings show diverse ranges of emerging structures including heterogeneous networks, aster-like structures, and densely bundled needle-like structures, which compare to configurations found in many other systems. These show a strong dependence not only on concentration and bundling strength, but also on the underlying mechanical properties of the nanotubes. Similar network architectures to those caused by depletion forces in the low-density regime are obtained when an alternative hybridization-based bundling mechanism is employed to induce self-assembly in an isotropic network of pre-formed DNA nanotubes. This emphasizes the universal effect inevitable attractive forces in crowded environments have on systems of self-assembling soft matter, which should be considered for macromolecular structures applied in crowded systems such as cells.

Three-Level De-Multiplexed Dual-Branch Complex Delta-Sigma Transmitter.

PubMed

Arfi, Anis Ben; Elsayed, Fahmi; Aflaki, Pouya M; Morris, Brad; Ghannouchi, Fadhel M

2018-02-20

In this paper, a dual-branch topology driven by a Delta-Sigma Modulator (DSM) with a complex quantizer, also known as the Complex Delta Sigma Modulator (CxDSM), with a 3-level quantized output signal is proposed. By de-multiplexing the 3-level Delta-Sigma-quantized signal into two bi-level streams, an efficiency enhancement over the operational frequency range is achieved. The de-multiplexed signals drive a dual-branch amplification block composed of two switch-mode back-to-back power amplifiers working at peak power. A signal processing technique known as quantization noise reduction with In-band Filtering (QNRIF) is applied to each of the de-multiplexed streams to boost the overall performances; particularly the Adjacent Channel Leakage Ratio (ACLR). After amplification, the two branches are combined using a non-isolated combiner, preserving the efficiency of the transmitter. A comprehensive study on the operation of this topology and signal characteristics used to drive the dual-branch Switch-Mode Power Amplifiers (SMPAs) was established. Moreover, this work proposes a highly efficient design of the amplification block based on a back-to-back power topology performing a dynamic load modulation exploiting the non-overlapping properties of the de-multiplexed Complex DSM signal. For experimental validation, the proposed de-multiplexed 3-level Delta-Sigma topology was implemented on the BEEcube™ platform followed by the back-to-back Class-E switch-mode power amplification block. The full transceiver is assessed using a 4th-Generation mobile communications standard LTE (Long Term Evolution) standard 1.4 MHz signal with a peak to average power ratio (PAPR) of 8 dB. The dual-branch topology exhibited a good linearity and a coding efficiency of the transmitter chain higher than 72% across the band of frequency from 1.8 GHz to 2.7 GHz.

Small-angle X-ray scattering and rheological characterization of alginate gels. 2. Time-resolved studies on ionotropic gels

NASA Astrophysics Data System (ADS)

Yuguchi, Y.; Urakawa, H.; Kajiwara, K.; Draget, K. I.; Stokke, B. T.

2000-10-01

Gelation was observed by time-resolved small-angle X-ray scattering and rheology on 10 mg/ml Ca-alginate gels prepared by in situ release of Ca 2+ from CaEGTA or CaCO 3 with total Ca 2+ concentration in the range 10-20 mM. This was carried out for alginates having a fraction of α- L-GulA (G) of FG=0.39 and 0.68, respectively, obtained by the selection of alginates isolated from two different brown algae, Ascophyllum nodosum and Laminaria hyperborea stipe. Correlation between the rheological data and SAXS data shows that a large fraction of the lateral association precedes the formation of a continuous network through the sample cell. Following the initial association of chain segments in junction zones, the analysis using two-component broken rod model indicates the formation of larger bundles, and that the relative weight of these bundles increases with increasing time. The molecular model for the bundles is proposed by associating 2-16 units (G-blocks) composed of 14 (1→4) linked residues of α- L-GulA in parallel according to the available crystallographic data. The storage modulus increases as the bundles composed of associated alginate chains grow during the gel formation. The gel elasticity is mainly sustained by single chains in the alginate sample with a low fraction of α- L-GulA. The alginates with a high fraction of α- L-GulA associate into thicker bundles which join to form a network. Here the gel elasticity seems to be due to the flexible joints between bundles, since the fraction of single chains is extremely low.

Defining the local nerve blocks for feline distal thoracic limb surgery: a cadaveric study

PubMed Central

Enomoto, Masataka; Lascelles, B Duncan X; Gerard, Mathew P

2016-01-01

Objectives Though controversial, onychectomy remains a commonly performed distal thoracic limb surgical procedure in cats. Peripheral nerve block techniques have been proposed in cats undergoing onychectomy but evidence of efficacy is lacking. Preliminary tests of the described technique using cadavers resulted in incomplete staining of nerves. The aim of this study was to develop nerve block methods based on cadaveric dissections and test these methods with cadaveric dye injections. Methods Ten pairs of feline thoracic limbs (n = 20) were dissected and superficial branches of the radial nerve (RSbr nn.), median nerve (M n.), dorsal branch of ulnar nerve (UDbr n.), superficial branch of palmar branch of ulnar nerve (UPbrS n.) and deep branch of palmar branch of ulnar nerve (UPbrDp n.) were identified. Based on these dissections, a four-point block was developed and tested using dye injections in another six pairs of feline thoracic limbs (n = 12). Using a 25 G × 5/8 inch needle and 1 ml syringe, 0.07 ml/kg methylene blue was injected at the site of the RSbr nn., 0.04 ml/kg at the injection site of the UDbr n., 0.08 ml/kg at the injection site of the M n. and UPbrS n., and 0.01 ml/kg at the injection site of the UPbrDp n. The length and circumference of each nerve that was stained was measured. Results Positive staining of all nerves was observed in 12/12 limbs. The lengths stained for RSbr nn., M n., UDbr n., UPbrS n. and UPbrDp n. were 34.9 ± 5.3, 26.4 ± 4.8, 29.2 ± 4.0, 39.1 ± 4.3 and 17.5 ± 3.3 mm, respectively. The nerve circumferences stained were 93.8 ± 15.5, 95.8 ± 9.7, 100 ± 0.0, 100 ± 0.0 and 93.8 ± 15.5%, respectively. Conclusions and relevance This described four-point injection method may be an effective perioperative analgesia technique for feline distal thoracic limb procedures. PMID:26250858

Structures of bacterial homologues of SWEET transporters in two distinct conformations.

PubMed

Xu, Yan; Tao, Yuyong; Cheung, Lily S; Fan, Chao; Chen, Li-Qing; Xu, Sophia; Perry, Kay; Frommer, Wolf B; Feng, Liang

2014-11-20

SWEETs and their prokaryotic homologues are monosaccharide and disaccharide transporters that are present from Archaea to plants and humans. SWEETs play crucial roles in cellular sugar efflux processes: that is, in phloem loading, pollen nutrition and nectar secretion. Their bacterial homologues, which are called SemiSWEETs, are among the smallest known transporters. Here we show that SemiSWEET molecules, which consist of a triple-helix bundle, form symmetrical, parallel dimers, thereby generating the translocation pathway. Two SemiSWEET isoforms were crystallized, one in an apparently open state and one in an occluded state, indicating that SemiSWEETs and SWEETs are transporters that undergo rocking-type movements during the transport cycle. The topology of the triple-helix bundle is similar yet distinct to that of the basic building block of animal and plant major facilitator superfamily (MFS) transporters (for example, GLUTs and SUTs). This finding indicates two possibilities: that SWEETs and MFS transporters evolved from an ancestral triple-helix bundle or that the triple-helix bundle represents convergent evolution. In SemiSWEETs and SWEETs, two triple-helix bundles are arranged in a parallel configuration to produce the 6- and 6 + 1-transmembrane-helix pores, respectively. In the 12-transmembrane-helix MFS transporters, four triple-helix bundles are arranged into an alternating antiparallel configuration, resulting in a much larger 2 × 2 triple-helix bundle forming the pore. Given the similarity of SemiSWEETs and SWEETs to PQ-loop amino acid transporters and to mitochondrial pyruvate carriers (MPCs), the structures characterized here may also be relevant to other transporters in the MtN3 clan. The insight gained from the structures of these transporters and from the analysis of mutations of conserved residues will improve the understanding of the transport mechanism, as well as allow comparative studies of the different superfamilies involved in sugar transport and the evolution of transporters in general.

Accuracy Analysis on Large Blocks of High Resolution Images

NASA Technical Reports Server (NTRS)

Passini, Richardo M.

2007-01-01

Although high altitude frequencies effects are removed at the time of basic image generation, low altitude (Yaw) effects are still present in form of affinity/angular affinity. They are effectively removed by additional parameters. Bundle block adjustment based on properly weighted ephemeris/altitude quaternions (BBABEQ) are not enough to remove the systematic effect. Moreover, due to the narrow FOV of the HRSI, position and altitude are highly correlated making it almost impossible to separate and remove their systematic effects without extending the geometric model (Self-Calib.) The systematic effects gets evident on the increase of accuracy (in terms of RMSE at GCPs) for looser and relaxed ground control at the expense of large and strong block deformation with large residuals at check points. Systematic errors are most freely distributed and their effects propagated all over the block.

Surfactant-free solvothermal synthesis of Hydroxyapatite nested bundles for the effective photodegradation of cationic dyes

NASA Astrophysics Data System (ADS)

Reeta Mary, I.; Sonia, S.; Navadeepthy, D.; Mangalaraj, D.; Viswanathan, C.; Ponpandian, N.

2018-05-01

In this study, hydroxyapatite nested bundles (HNBs) were successfully constructed from nanosticks as nanoscale building blocks via a facile, solvothermal process without using any surfactant. The fabricated HNBs were structurally analyzed using X-ray diffraction and Fourier transform infrared spectroscopy, which confirmed the purity of the HNBs. The surface characteristics were determined by field emission scanning electron microscopy and Brunauer-Emmett-Teller analysis, and the optical characteristics by ultraviolet (UV)-visible spectroscopy. The synthesized HNBs were tested to determine their activity during the degradation of methylene blue, methylene violet, and rhodamine B via photocatalysis under UV irradiation. The degradation efficiency of HNBs and the rate of degradation can be explained based on the properties of the HNBs and cationic dyes.

Effects of nanoparticle shape on the morphology and properties of porous CdSe assemblies (aerogels).

PubMed

Yu, Hongtao; Brock, Stephanie L

2008-08-01

We demonstrate the effect of differently shaped CdSe nanoscale building blocks (dots, rods, branched nanoparticles, and hyperbranched nanoparticles) on the morphologies, surface characteristics, and optical properties of resultant porous CdSe nanostructured aerogels. Monolithic CdSe aerogels were produced by controlled oxidative removal of surface thiolate ligands from differently shaped CdSe nanoparticles to yield a wet gel, followed by CO(2) supercritical drying. The X-ray diffraction data show that the resultant CdSe aerogels maintain the crystalline phase of the building blocks without significant grain growth. However, the transmission electron microscopy images indicate that the morphology of CdSe aerogels changes from a colloid-type morphology to a polymer-type morphology when the building block changes from dot to rod or the branched nanoparticle. The morphology of the CdSe aerogel assembled from hyperbranched nanoparticles appears to be intermediate between the colloid-type and the polymer-type. Nitrogen physisorption measurements suggest that the surface areas and porosity are a direct function of the shape of the primary building blocks, with aerogels formed from rods or branched particles exhibiting the greatest surface areas (>200 m(2)/g) and those prepared from hyperbranched nanoparticles exhibiting the least (<100 m(2)/g). Band gap measurements and photoluminescence studies show that the as-prepared CdSe aerogels retain to a large extent the intrinsic quantum confinement of the differently shaped building blocks, despite being connected into a 3D network.

18. METAL LIGHT STANDARD, AT NORTH END BLOCK OF EAST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. METAL LIGHT STANDARD, AT NORTH END BLOCK OF EAST PARAPET, FROM NORTH, SHOWING ORIGINAL LIGHT STANDARD, WITH REPLACEMENT BRACKET AND COBRA-HEAD LAMP - Fifth Street Viaduct, Spanning Bacon's Quarter Branch Valley on Fifth Street, Richmond, Independent City, VA

[Ultrasound-guided cutaneous intercostal branches nerves block: A good analgesic alternative for gallbladder open surgery].

PubMed

Fernández Martín, M T; López Álvarez, S; Mozo Herrera, G; Platero Burgos, J J

2015-12-01

Laparoscopic cholecystectomy has become the standard treatment for gallbladder diseases. However, there are still some patients for whom conversion to open surgery is required. This surgery can produce significant post-operative pain. Opioids drugs have traditionally been used to treat this pain, but side effects have led to seeking alternatives (plexus, nerve or fascia blocks or wound). The cases are presented of 4 patients subjected to ultrasound-guided intercostal branches blocks in the mid-axillary line from T6 to T12 with levobupivacaine as an analgesic alternative in open surgery of gallbladder, with satisfactory results. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

New branched DNA constructs.

PubMed

Chandra, Madhavaiah; Keller, Sascha; Gloeckner, Christian; Bornemann, Benjamin; Marx, Andreas

2007-01-01

The Watson-Crick base pairing of DNA is an advantageous phenomenon that can be exploited when using DNA as a scaffold for directed self-organization of nanometer-sized objects. Several reports have appeared in the literature that describe the generation of branched DNA (bDNA) with variable numbers of arms that self-assembles into predesigned architectures. These bDNA units are generated by using cleverly designed rigid crossover DNA molecules. Alternatively, bDNA can be generated by using synthetic branch points derived from either nucleoside or non-nucleoside building blocks. Branched DNA has scarcely been explored for use in nanotechnology or from self-assembling perspectives. Herein, we wish to report our results for the synthesis, characterization, and assembling properties of asymmetrical bDNA molecules that are able to generate linear and circular bDNA constructs. Our strategy for the generation of bDNA is based on a branching point that makes use of a novel protecting-group strategy. The bDNA units were generated by means of automated DNA synthesis methods and were used to generate novel objects by employing chemical and biological techniques. The entities generated might be useful building blocks for DNA-based nanobiotechnology.

Anatomical study of the articular branches innervated the hip and knee joint with reference to mechanism of referral pain in hip joint disease patients.

PubMed

Sakamoto, Junya; Manabe, Yoshitaka; Oyamada, Joichi; Kataoka, Hideki; Nakano, Jiro; Saiki, Kazunobu; Okamoto, Keishi; Tsurumoto, Toshiyuki; Okita, Minoru

2018-07-01

Referred pain in the anterior knee joint is the most common symptom in hip disease patients. The development of referred pain is considered to be related to dichotomizing peripheral sensory fibers. However, no gross anatomical findings identify any dichotomizing fibers innervating both the hip and knee joints. We dissected the femoral and obturator nerves in human cadavers to investigate the distribution of the articular branches in the hip and knee joints. Fourteen embalmed left lower limbs from 14 Japanese adult cadavers (five from females, nine from males, average age 73.8 ± 14.1 years) were observed macroscopically. The articular branches of the femoral and obturator nerves were dissected at the anterior margin of the groin toward the thigh region. After dissections of the articular nerves of the hip joints, the femoral and obturator nerves were exposed from proximally to distally to identify the articular nerves of the knee joints. The branching pattern of the articular branches in the hip and knee joints was recorded. In six of 14 limbs (42.9%), the femoral nerve supplied articular branches to the anteromedial aspect of both the hip and knee joints. These articular branches were derived from the same bundle of femoral nerve. These gross anatomical findings suggested that dichotomizing peripheral sensory fibers innervate the hip and knee joints and these could relate to the referred pain confirmed in the anterior knee joints of patients with hip disease. Clin. Anat. 31:705-709, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Flexible ex vivo phantoms for validation of diffusion tensor tractography on a clinical scanner.

PubMed

Watanabe, Makoto; Aoki, Shigeki; Masutani, Yoshitaka; Abe, Osamu; Hayashi, Naoto; Masumoto, Tomohiko; Mori, Harushi; Kabasawa, Hiroyuki; Ohtomo, Kuni

2006-11-01

The aim of this study was to develop ex vivo diffusion tensor (DT) flexible phantoms. Materials were bundles of textile threads of cotton, monofilament nylon, rayon, and polyester bunched with spiral wrapping bands and immersed in water. DT images were acquired on a 1.5-Tesla clinical magnetic resonance scanner using echo planar imaging sequences with 15 motion probing gradient directions. DT tractography with seeding and a line-tracking method was carried out by software originally developed on a PC-based workstation. We observed relatively high fractional anisotropy on the polyester phantom and were able to reconstruct tractography. Straight tracts along the bundle were displayed when it was arranged linearly. It was easy to bend arcuately or bifurcate at one end; and tracts followed the course of the bundle, whether it was curved or branched and had good agreement with direct visual observation. Tractography with the other fibers was unsuccessful. The polyester phantom revealed a diffusion anisotropic structure according to its shape and would be utilizable repeatedly under the same conditions, differently from living central neuronal system. It would be useful to validate DT sequences and to optimize an algorithm or parameters of DT tractography software. Additionally, the flexibility of the phantom would enable us to model human axonal projections.

The activity state of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.

PubMed Central

Wagenmakers, A J; Schepens, J T; Veldhuizen, J A; Veerkamp, J H

1984-01-01

An assay is described to define the proportion of the branched-chain 2-oxo acid dehydrogenase complex that is present in the active state in rat tissues. Activities are measured in homogenates in two ways: actual activities, present in tissues, by blocking both the kinase and phosphatase of the enzyme complex during homogenization, preincubation, and incubation with 1-14C-labelled branched-chain 2-oxo acid, and total activities by blocking only the kinase during the 5 min preincubation (necessary for activation). The kinase is blocked by 5 mM-ADP and absence of Mg2+ and the phosphatase by the simultaneous presence of 50 mM-NaF. About 6% of the enzyme is active in skeletal muscle of fed rats, 7% in heart, 20% in diaphragm, 47% in kidney, 60% in brain and 98% in liver. An entirely different assay, which measures activities in crude tissue extracts before and after treatment with a broad-specificity protein phosphatase, gave similar results for heart, liver and kidney. Advantages of our assay with homogenates are the presence of intact mitochondria, the simplicity, the short duration and the high sensitivity. The actual activities measured indicate that the degradation of branched-chain 2-oxo acids predominantly occurs in liver and kidney and is limited in skeletal muscle in the fed state. PMID:6430280

The activity state of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.

PubMed

Wagenmakers, A J; Schepens, J T; Veldhuizen, J A; Veerkamp, J H

1984-05-15

An assay is described to define the proportion of the branched-chain 2-oxo acid dehydrogenase complex that is present in the active state in rat tissues. Activities are measured in homogenates in two ways: actual activities, present in tissues, by blocking both the kinase and phosphatase of the enzyme complex during homogenization, preincubation, and incubation with 1-14C-labelled branched-chain 2-oxo acid, and total activities by blocking only the kinase during the 5 min preincubation (necessary for activation). The kinase is blocked by 5 mM-ADP and absence of Mg2+ and the phosphatase by the simultaneous presence of 50 mM-NaF. About 6% of the enzyme is active in skeletal muscle of fed rats, 7% in heart, 20% in diaphragm, 47% in kidney, 60% in brain and 98% in liver. An entirely different assay, which measures activities in crude tissue extracts before and after treatment with a broad-specificity protein phosphatase, gave similar results for heart, liver and kidney. Advantages of our assay with homogenates are the presence of intact mitochondria, the simplicity, the short duration and the high sensitivity. The actual activities measured indicate that the degradation of branched-chain 2-oxo acids predominantly occurs in liver and kidney and is limited in skeletal muscle in the fed state.

The Drosophila L1CAM homolog Neuroglian signals through distinct pathways to control different aspects of mushroom body axon development

PubMed Central

Goossens, Tim; Kang, Yuan Y.; Wuytens, Gunther; Zimmermann, Pascale; Callaerts-Végh, Zsuzsanna; Pollarolo, Giulia; Islam, Rafique; Hortsch, Michael; Callaerts, Patrick

2011-01-01

The spatiotemporal integration of adhesion and signaling during neuritogenesis is an important prerequisite for the establishment of neuronal networks in the developing brain. In this study, we describe the role of the L1-type CAM Neuroglian protein (NRG) in different steps of Drosophila mushroom body (MB) neuron axonogenesis. Selective axon bundling in the peduncle requires both the extracellular and the intracellular domain of NRG. We uncover a novel role for the ZO-1 homolog Polychaetoid (PYD) in axon branching and in sister branch outgrowth and guidance downstream of the neuron-specific isoform NRG-180. Furthermore, genetic analyses show that the role of NRG in different aspects of MB axonal development not only involves PYD, but also TRIO, SEMA-1A and RAC1. PMID:21389050

The Drosophila L1CAM homolog Neuroglian signals through distinct pathways to control different aspects of mushroom body axon development.

PubMed

Goossens, Tim; Kang, Yuan Y; Wuytens, Gunther; Zimmermann, Pascale; Callaerts-Végh, Zsuzsanna; Pollarolo, Giulia; Islam, Rafique; Hortsch, Michael; Callaerts, Patrick

2011-04-01

The spatiotemporal integration of adhesion and signaling during neuritogenesis is an important prerequisite for the establishment of neuronal networks in the developing brain. In this study, we describe the role of the L1-type CAM Neuroglian protein (NRG) in different steps of Drosophila mushroom body (MB) neuron axonogenesis. Selective axon bundling in the peduncle requires both the extracellular and the intracellular domain of NRG. We uncover a novel role for the ZO-1 homolog Polychaetoid (PYD) in axon branching and in sister branch outgrowth and guidance downstream of the neuron-specific isoform NRG-180. Furthermore, genetic analyses show that the role of NRG in different aspects of MB axonal development not only involves PYD, but also TRIO, SEMA-1A and RAC1.

Developmental pattern of ANF gene expression reveals a strict localization of cardiac chamber formation in chicken.

PubMed

Houweling, Arjan C; Somi, Semir; Van Den Hoff, Maurice J B; Moorman, Antoon F M; Christoffels, Vincent M

2002-02-01

In mouse, atrial natriuretic factor (ANF) gene expression was shown to be a marker for chamber formation within the embryonic heart. To gain insight into the process of chamber formation in the chicken embryonic heart, we analyzed the expression pattern of cANF during development. We found cANF to be specifically expressed in the myocardium of the morphologically distinguishable atrial and ventricular chambers, similar to ANF in mouse. cANF expression was never detected in the myocardium of the atrioventricular canal (AVC), inner curvature, and outflow tract (OFT), which is lined by endocardial cushions. Expression was strictly excluded from the interventricular myocardium and most proximal part of the bundle branches, as identified by the expression of Msx-2, whereas the rest of the bundle branches, trabeculae, and surrounding working myocardium did express cANF. The myocardium that forms de novo within the cushions after looping did not express cANF. At HH9 cANF expression was first observed in a subset of cardiomyocytes, which was localized ventrally in the fused heart tube and laterally in the unfused cardiac sheets. Together, these results show that cANF expression can be used to distinguish differentiated chamber (working) myocardium, including the peripheral ventricular conduction system, from embryonic myocardium. We conclude that differentiation of chamber myocardium takes place already at HH9 at the ventral side of the linear heart tube, possibly preceded by latero-medial signals in the unfused cardiac sheets. Copyright 2002 Wiley-Liss, Inc.

Understanding Peptide Oligomeric State in Langmuir Monolayers of Amphiphilic 3-Helix Bundle-Forming Peptide-PEG Conjugates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lund, Reidar; Ang, JooChuan; Shu, Jessica Y.

Coiled-coil peptide-polymer conjugates are an emerging class of biomaterials. Fundamental understanding of the coiled-coil oligomeric state and assembly process of these hybrid building blocks is necessary to exert control over their assembly into well-defined structures. Here in this paper, we studied the effect of peptide structure and PEGylation on the self-assembly process and oligomeric state of a Langmuir monolayer of amphiphilic coiled-coil peptide-polymer conjugates using X-ray reflectivity (XR) and grazing-incidence X-ray diffraction (GIXD). Our results show that the oligomeric state of PEGylated amphiphiles based on 3-helix bundle-forming peptide is surface pressure dependent, a mixture of dimers and trimers was formedmore » at intermediate surface pressure but transitions into trimers completely upon increasing surface pressure. Moreover, the interhelical distance within the coiled-coil bundle of 3-helix peptide-PEG conjugate amphiphiles was not perturbed under high surface pressure. Present studies provide valuable insights into the self-assembly process of hybrid peptide-polymer conjugates and guidance to develop biomaterials with controlled multivalency of ligand presentation.« less

Understanding Peptide Oligomeric State in Langmuir Monolayers of Amphiphilic 3-Helix Bundle-Forming Peptide-PEG Conjugates

DOE PAGES

Lund, Reidar; Ang, JooChuan; Shu, Jessica Y.; ...

2016-10-26

Coiled-coil peptide-polymer conjugates are an emerging class of biomaterials. Fundamental understanding of the coiled-coil oligomeric state and assembly process of these hybrid building blocks is necessary to exert control over their assembly into well-defined structures. Here in this paper, we studied the effect of peptide structure and PEGylation on the self-assembly process and oligomeric state of a Langmuir monolayer of amphiphilic coiled-coil peptide-polymer conjugates using X-ray reflectivity (XR) and grazing-incidence X-ray diffraction (GIXD). Our results show that the oligomeric state of PEGylated amphiphiles based on 3-helix bundle-forming peptide is surface pressure dependent, a mixture of dimers and trimers was formedmore » at intermediate surface pressure but transitions into trimers completely upon increasing surface pressure. Moreover, the interhelical distance within the coiled-coil bundle of 3-helix peptide-PEG conjugate amphiphiles was not perturbed under high surface pressure. Present studies provide valuable insights into the self-assembly process of hybrid peptide-polymer conjugates and guidance to develop biomaterials with controlled multivalency of ligand presentation.« less

Self-assembled nanocages based on the coiled coil bundle motif

NASA Astrophysics Data System (ADS)

Sinha, Nairiti; Villegas, Jose; Saven, Jeffery; Kiick, Kristi; Pochan, Darrin

Computational design of coiled coil peptide bundles that undergo solution phase self-assembly presents a diverse toolbox for engineering new materials with tunable and pre-determined nanostructures that can have various end applications such as in drug delivery, biomineralization and electronics. Self-assembled cages are especially advantageous as the cage geometry provides three distinct functional sites: the interior, the exterior and the solvent-cage interface. In this poster, syntheses and characterization of a peptide cage based on computationally designed homotetrameric coiled coil bundles as building blocks is discussed. Techniques such as Transmission Electron Microscopy (TEM), Small-Angle Neutron Scattering (SANS) and Analytical Ultracentrifugation (AUC) are employed to characterize the size, shape and molecular weight of the self-assembled peptide cages under different pH and temperature conditions. Various self-assembly pathways such as dialysis and thermal quenching are shown to have a significant impact on the final structure of these peptides in solution. Comparison of results with the target cage design can be used to iteratively improve the peptide design and provide greater understanding of its interactions and folding.

Catheter ablation of ventricular ectopy with para-hisian origin: importance of mapping both sides of the interventricular septum and understanding when to stop ablating.

PubMed

Madaffari, Antonio; Große, Anett; Raffa, Santi; Frommhold, Markus; Fink, Agnes; Geller, J Christoph

2016-12-01

Catheter ablation of para-Hisian premature ventricular contractions (PVCs) still represents a challenge and is a compromise between success and inadvertent AV block. We describe a possible strategy to address PVCs from this location with high-amplitude His-bundle potentials at the site of earliest activation.

Bundle Block Adjustment of Airborne Three-Line Array Imagery Based on Rotation Angles

PubMed Central

Zhang, Yongjun; Zheng, Maoteng; Huang, Xu; Xiong, Jinxin

2014-01-01

In the midst of the rapid developments in electronic instruments and remote sensing technologies, airborne three-line array sensors and their applications are being widely promoted and plentiful research related to data processing and high precision geo-referencing technologies is under way. The exterior orientation parameters (EOPs), which are measured by the integrated positioning and orientation system (POS) of airborne three-line sensors, however, have inevitable systematic errors, so the level of precision of direct geo-referencing is not sufficiently accurate for surveying and mapping applications. Consequently, a few ground control points are necessary to refine the exterior orientation parameters, and this paper will discuss bundle block adjustment models based on the systematic error compensation and the orientation image, considering the principle of an image sensor and the characteristics of the integrated POS. Unlike the models available in the literature, which mainly use a quaternion to represent the rotation matrix of exterior orientation, three rotation angles are directly used in order to effectively model and eliminate the systematic errors of the POS observations. Very good experimental results have been achieved with several real datasets that verify the correctness and effectiveness of the proposed adjustment models. PMID:24811075

Bundle block adjustment of airborne three-line array imagery based on rotation angles.

PubMed

Zhang, Yongjun; Zheng, Maoteng; Huang, Xu; Xiong, Jinxin

2014-05-07

In the midst of the rapid developments in electronic instruments and remote sensing technologies, airborne three-line array sensors and their applications are being widely promoted and plentiful research related to data processing and high precision geo-referencing technologies is under way. The exterior orientation parameters (EOPs), which are measured by the integrated positioning and orientation system (POS) of airborne three-line sensors, however, have inevitable systematic errors, so the level of precision of direct geo-referencing is not sufficiently accurate for surveying and mapping applications. Consequently, a few ground control points are necessary to refine the exterior orientation parameters, and this paper will discuss bundle block adjustment models based on the systematic error compensation and the orientation image, considering the principle of an image sensor and the characteristics of the integrated POS. Unlike the models available in the literature, which mainly use a quaternion to represent the rotation matrix of exterior orientation, three rotation angles are directly used in order to effectively model and eliminate the systematic errors of the POS observations. Very good experimental results have been achieved with several real datasets that verify the correctness and effectiveness of the proposed adjustment models.

Identification of a D-amino acid decapeptide HIV-1 entry inhibitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boggiano, Cesar; Jiang Shibo; Lu Hong

2006-09-08

Entry of human immunodeficiency virus type 1 (HIV-1) virion into host cells involves three major steps, each being a potential target for the development of entry inhibitors: gp120 binding to CD4, gp120-CD4 complex interacting with a coreceptor, and gp41 refolding to form a six-helix bundle. Using a D-amino acid decapeptide combinatorial library, we identified peptide DC13 as having potent HIV-1 fusion inhibitory activity, and effectively inhibiting infection by several laboratory-adapted and primary HIV-1 strains. While DC13 did not block binding of gp120 to CD4, nor disrupt the gp41 six-helix bundle formation, it effectively blocked the binding of an anti-CXCR4 monoclonalmore » antibody and chemokine SDF-1{alpha} to CXCR4-expressing cells. However, because R5-using primary viruses were also neutralized, the antiviral activity of DC13 implies additional mode(s) of action. These results suggest that DC13 is a useful HIV-1 coreceptor antagonist for CXCR4 and, due to its biostability and simplicity, may be of value for developing a new class of HIV-1 entry inhibitors.« less

Cost Utility Analysis of Cervical Therapeutic Medial Branch Blocks in Managing Chronic Neck Pain

PubMed Central

Manchikanti, Laxmaiah; Pampati, Vidyasagar; Kaye, Alan D.; Hirsch, Joshua A.

2017-01-01

Background:Controlled diagnostic studies have established the prevalence of cervical facet joint pain to range from 36% to 67% based on the criterion standard of ≥ 80% pain relief. Treatment of cervical facet joint pain has been described with Level II evidence of effectiveness for therapeutic facet joint nerve blocks and radiofrequency neurotomy and with no significant evidence for intraarticular injections. However, there have not been any cost effectiveness or cost utility analysis studies performed in managing chronic neck pain with or without headaches with cervical facet joint interventions. Study Design:Cost utility analysis based on the results of a double-blind, randomized, controlled trial of cervical therapeutic medial branch blocks in managing chronic neck pain. Objectives:To assess cost utility of therapeutic cervical medial branch blocks in managing chronic neck pain. Methods: A randomized trial was conducted in a specialty referral private practice interventional pain management center in the United States. This trial assessed the clinical effectiveness of therapeutic cervical medial branch blocks with or without steroids for an established diagnosis of cervical facet joint pain by means of controlled diagnostic blocks. Cost utility analysis was performed with direct payment data for the procedures for a total of 120 patients over a period of 2 years from this trial based on reimbursement rates of 2016. The payment data provided direct procedural costs without inclusion of drug treatments. An additional 40% was added to procedural costs with multiplication of a factor of 1.67 to provide estimated total costs including direct and indirect costs, based on highly regarded surgical literature. Outcome measures included significant improvement defined as at least a 50% improvement with reduction in pain and disability status with a combined 50% or more reduction in pain in Neck Disability Index (NDI) scores. Results:The results showed direct procedural costs per one-year improvement in quality adjusted life year (QALY) of United States Dollar (USD) of $2,552, and overall costs of USD $4,261. Overall, each patient on average received 5.7 ± 2.2 procedures over a period of 2 years. Average significant improvement per procedure was 15.6 ± 12.3 weeks and average significant improvement in 2 years per patient was 86.0 ± 24.6 weeks. Limitations:The limitations of this cost utility analysis are that data are based on a single center evaluation. Only costs of therapeutic interventional procedures and physician visits were included, with extrapolation of indirect costs. Conclusion:The cost utility analysis of therapeutic cervical medial branch blocks in the treatment of chronic neck pain non-responsive to conservative management demonstrated clinical effectiveness and cost utility at USD $4,261 per one year of QALY. PMID:29200944

Cost Utility Analysis of Cervical Therapeutic Medial Branch Blocks in Managing Chronic Neck Pain.

PubMed

Manchikanti, Laxmaiah; Pampati, Vidyasagar; Kaye, Alan D; Hirsch, Joshua A

2017-01-01

Background: Controlled diagnostic studies have established the prevalence of cervical facet joint pain to range from 36% to 67% based on the criterion standard of ≥ 80% pain relief. Treatment of cervical facet joint pain has been described with Level II evidence of effectiveness for therapeutic facet joint nerve blocks and radiofrequency neurotomy and with no significant evidence for intraarticular injections. However, there have not been any cost effectiveness or cost utility analysis studies performed in managing chronic neck pain with or without headaches with cervical facet joint interventions. Study Design: Cost utility analysis based on the results of a double-blind, randomized, controlled trial of cervical therapeutic medial branch blocks in managing chronic neck pain. Objectives: To assess cost utility of therapeutic cervical medial branch blocks in managing chronic neck pain. Methods: A randomized trial was conducted in a specialty referral private practice interventional pain management center in the United States. This trial assessed the clinical effectiveness of therapeutic cervical medial branch blocks with or without steroids for an established diagnosis of cervical facet joint pain by means of controlled diagnostic blocks. Cost utility analysis was performed with direct payment data for the procedures for a total of 120 patients over a period of 2 years from this trial based on reimbursement rates of 2016. The payment data provided direct procedural costs without inclusion of drug treatments. An additional 40% was added to procedural costs with multiplication of a factor of 1.67 to provide estimated total costs including direct and indirect costs, based on highly regarded surgical literature. Outcome measures included significant improvement defined as at least a 50% improvement with reduction in pain and disability status with a combined 50% or more reduction in pain in Neck Disability Index (NDI) scores. Results: The results showed direct procedural costs per one-year improvement in quality adjusted life year (QALY) of United States Dollar (USD) of $2,552, and overall costs of USD $4,261. Overall, each patient on average received 5.7 ± 2.2 procedures over a period of 2 years. Average significant improvement per procedure was 15.6 ± 12.3 weeks and average significant improvement in 2 years per patient was 86.0 ± 24.6 weeks. Limitations: The limitations of this cost utility analysis are that data are based on a single center evaluation. Only costs of therapeutic interventional procedures and physician visits were included, with extrapolation of indirect costs. Conclusion: The cost utility analysis of therapeutic cervical medial branch blocks in the treatment of chronic neck pain non-responsive to conservative management demonstrated clinical effectiveness and cost utility at USD $4,261 per one year of QALY.

Distribution of branches in whole starches from maize mutants deficient in starch synthase III.

PubMed

Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

2014-05-21

An earlier study explored the possibility of analyzing the distribution of branches directly in native, whole starch without isolating the amylopectin component. The aim of this study was to explore if this approach can be extended to include starch mutants. Whole starches from du1 maize mutants deficient in starch synthase III (SSIII) with amylose content of ∼30-40% were characterized and compared with the wild type of the common genetic background W64A. Clusters were produced from whole starch by hydrolysis with α-amylase of Bacillus amyloliquefaciens. Their compositions of building blocks and chains were analyzed further by complete α-amylolysis and by debranching, respectively, whereafter the products were subjected to gel permeation and anion exchange chromatography. The size and structure of the clusters were compared with those of their isolated amylopectin component. Whereas the whole starch of the wild type sample had a branched structure similar to that of its amylopectin component, the results showed that the du1 mutation resulted in more singly branched building blocks in the whole starch compared to the isolated amylopectin. This suggested that amylose and/or intermediate materials in whole du1 starches likely contributed to the composition of branches. This study explored an alternative procedure to characterize the composition of branches in the whole starch without fractionating the components.

[Tako-tsubo syndrome: analysis of a series of 60 cases].

PubMed

Nogales-Asensio, Juan Manuel; González-Fernández, Maria Reyes; López-Mínguez, Jose Ramón; Merchán-Herrera, Antonio; Martínez-Cáceres, Ginés; Aranda-López, Carlos

2014-09-15

The Tako-tsubo syndrome (TS) is a reversible acute cardiomyopathy simulating an infarction. We analyzed 60 patients admitted with TS in our center. A percentage of 73.3 were women (mean age: 70.6 ± 11.8 years); 83.3% had some cardiovascular risk factor, 25% had an anxiety-depressive disorder and in 58.3% a precipitating factor was identified, emotional stress being the most frequent. A percentage of 15.3 showed complete left bundle branch block (LBBB). In 23.3% of patients, contractile abnormalities respected the apex (mid ventricular or diaphragmatic types). The anterior descending artery showed no significant lesions in 35% of patients and in 68.3% it had a diaphragmatic segment. Forty percent of patients developed heart failure (HF) and 18.3% cardiogenic shock (CS). The overall in-hospital mortality was 3.3%, while it was 8.3% among those patients who developed HF. The incidence of CS was higher among patients with LBBB (44.4 vs. 13.7%, P=.05) and males (43.8 vs. 9.1%, P=.005). Although in-hospital mortality in patients admitted due to TS is low, a significant percentage of these patients develop HF with a high mortality in this subgroup. Males and patients with LBBB had higher in-hospital morbidity. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Respiratory function impairment and cardiopulmonary consequences in long-time residents of the Canadian Arctic.

PubMed Central

Schaefer, O; Eaton, R D; Timmermans, F J; Hildes, J A

1980-01-01

Spirometry, roentgenography and electrocardiography were performed during community health surveys in 1976-78 in 176 Inuit and other long-time residents of the northeastern (Arctic Bay) and western (Inuvik) Canadian Arctic, and the results were related to age, ethnic origin, occupation and history of climatic exposure, smoking and hospitalization for tuberculosis. In Arctic Bay the young men showed excellent respiratory function, normal-sized pulmonary arteries and normal electrocardiograms, but abnormalities of all three types were increasingly frequent and severe after age 25. The forced mid-expiratory flow (FMF) fell to less than 50% of the norm by age 40, and dilatation of the pulmonary artery, hypertrophy of the right ventricle, right bundle branch block and a pseudoinfarction pattern on the ECG were frequently associated. In contrast, the men in Inuvik, an urbanized centre, maintained above normal respiratory function until age 40, and the FMF and pulmonary artery diameter remained normal in the older men except for Inuit and white trappers over 60 years old who had run fox trap lines along the Arctic coast in the 1920s and 30s. These data suggest that inhalation of extremely cold air at maximum ventilation may be a prime factor in the chronic obstructive lung disease of Inuit hunters, whereas smoking has only a minor role and hospitalization for tuberculosis appears to protect from rather than contribute to this disorder. PMID:7448675

Respiratory function impairment and cardiopulmonary consequences in long-time residents of the Canadian Arctic.

PubMed

Schaefer, O; Eaton, R D; Timmermans, F J; Hildes, J A

1980-11-22

Spirometry, roentgenography and electrocardiography were performed during community health surveys in 1976-78 in 176 Inuit and other long-time residents of the northeastern (Arctic Bay) and western (Inuvik) Canadian Arctic, and the results were related to age, ethnic origin, occupation and history of climatic exposure, smoking and hospitalization for tuberculosis. In Arctic Bay the young men showed excellent respiratory function, normal-sized pulmonary arteries and normal electrocardiograms, but abnormalities of all three types were increasingly frequent and severe after age 25. The forced mid-expiratory flow (FMF) fell to less than 50% of the norm by age 40, and dilatation of the pulmonary artery, hypertrophy of the right ventricle, right bundle branch block and a pseudoinfarction pattern on the ECG were frequently associated. In contrast, the men in Inuvik, an urbanized centre, maintained above normal respiratory function until age 40, and the FMF and pulmonary artery diameter remained normal in the older men except for Inuit and white trappers over 60 years old who had run fox trap lines along the Arctic coast in the 1920s and 30s. These data suggest that inhalation of extremely cold air at maximum ventilation may be a prime factor in the chronic obstructive lung disease of Inuit hunters, whereas smoking has only a minor role and hospitalization for tuberculosis appears to protect from rather than contribute to this disorder.

Role of echocardiography before cardiac resynchronization therapy: new advances and current developments.

PubMed

Marechaux, Sylvestre; Menet, Aymeric; Guyomar, Yves; Ennezat, Pierre-Vladimir; Guerbaai, Raphaëlle Ashley; Graux, Pierre; Tribouilloy, Christophe

2016-11-01

The role of echocardiography in improving the selection of patients who will benefit from cardiac resynchronization therapy (CRT) remains a source of debate. Although previous landmark reports have demonstrated a link between mechanical dyssynchrony, assessed by delays between left ventricle (LV) walls and response to CRT, the predictive value of these findings has not yet been confirmed in multicenter trials. Indeed, recent studies demonstrated that the classical assessment of LV mechanical dyssynchrony using delay between walls by echocardiography depends not only on LV electrical activation delay (electrical dyssynchrony), but also on abnormalities in regional contractility of the LV and/or loading conditions, which do not represent an appropriate target for CRT. Recent reports highlighted the value of new indices of electromechanical dyssynchrony obtained by echocardiography, to predict LV response and outcome after CRT including septal flash, left bundle branch block-typical pattern by longitudinal strain, apical rocking, septal strain patterns, and systolic stretch index. This was achieved using a mechanistic approach, based on the contractile consequences of electrical dyssynchrony. These indices are rarely found in patients with narrow QRS (<120 ms), whereas their frequency rises in patients with an increase in QRS duration (>120 ms). Theses indices should improve candidate selection for CRT in clinical practice, especially for patients in whom the benefit of CRT remains uncertain, for example, patients with intermediate QRS width (120-150 ms). © 2016, Wiley Periodicals, Inc.

[Metabolic activity of neutrophilic granulocytes and possible ways of its correction in patients with acute coronary syndrome].

PubMed

Ryzhkova, N A; Havrylenko, T I; Parkhomenko, O M; Kozhukhov, S M

2011-01-01

The present study aimed to investigate the metabolic activity of neutrocytes and the action of corvitin on the level of superoxide anion and myeloperoxidases of cells in vitro with the calculation of index of consumption of myeloperoxidase in patients with ST-elevation acute coronary syndrome. Patient were divided into 2 groups according to the level of superoxide anion. Group 1 included the patients (68%) with the initially low level of superoxide anion, and adding of corvitin to the cells of such patients promoted normalization of this index. In this group we observed also neutrocytosis, low index of consumption of myeloperoxidase and a high level of this enzyme in general population of neutrocytes. Group 2 included patients (32%) with initially normal level of superoxide anion. In this group, corvitin did not influence substantially this factor. Such patients had a level ofmyeloperoxidase within control values and the index of consumption of this enzyme was also within control values. The analysis of hospital period showed that the patients of group 1 had a higher frequency of ventricular tachycardia/ventricular fibrillation, paroxysms of atrial fibrillation, bundle-branch blocks and worsening of the kidney function. We suppose that a low level of superoxide anion in neutrocytes play a major role in the development of complications in patients with acute coronary syndrome. An intravenous administration of corvitin was effective in restoring the metabolic activity of neutrocytes.

Minimally invasive surgical implantation of left ventricular epicardial leads for ventricular resynchronization using video-assisted thoracoscopy.

PubMed

Fernández, Angel L; García-Bengochea, José B; Ledo, Ramiro; Vega, Marino; Amaro, Antonio; Alvarez, Julián; Rubio, José; Sierra, Juan; Sánchez, Daniel

2004-04-01

Cardiac resynchronization via left ventricular or biventricular pacing is an option for selected patients with ventricular systolic dysfunction and widened QRS complex. Stimulation through a coronary vein is the technique of choice for left ventricular pacing, but this approach results in a failure rate of approximately 8%. We describe our initial experience with minimally invasive surgical implantation of left ventricular epicardial leads using video-assisted thoracoscopy. A total of 14 patients with congestive heart failure, NYHA functional class 3.2 (0.6) and mean ejection fraction 22.9 (6.8)% were included in this study. Left bundle branch block, QRS complex >140 ms and abnormal septal motion were observed in all cases. Epicardial leads were implanted on the left ventricular free wall under general anesthesia using video-assisted thoracoscopic surgery. Lead implantation was successful in 13 patients. Conversion to a small thoracotomy was necessary in one patient. All patients were extubated in the operating room. None of the patients died during their hospital stay. Follow-up showed reversal of ventricular asynchrony and significant improvement in ejection fraction and functional class. Minimally invasive surgery for ventricular resynchronization using video-assisted thoracoscopy in selected patients is a safe procedure that makes it possible to choose the best site for lead implantation and provides adequate short- and medium-term stimulation.

Early electrocardiographic abnormalities in Trypanosoma cruzi-seropositive children.

PubMed

de Andrade, A L; Zicker, F; Rassi, A; Rassi, A G; Oliveira, R M; Silva, S A; de Andrade, S S; Martelli, C M

1998-10-01

As part of a major epidemiologic study on Chagas' disease, we compared the prevalence of electrocardiographic (ECG) abnormalities among 141 school children 7-12 years of age and seropositive for Trypanosoma cruzi, and 282 age-, sex-, and school-matched seronegative children in an endemic area in Brazil. The prevalence of ECG abnormalities was 11.3% among seropositive children and 3.5% among seronegative children (odds ratio = 3.5, 95% confidence interval [CI] = 1.5-8.4). The prevalence rate of ECG alterations was 10.7% for seropositive males versus 8.9% for seropositive females. Complete right bundle branch block (CRBBB), which is highly suggestive of Chagas' disease cardiopathy, was diagnosed in nine (6.4%) seropositive children and in only one (0.3%) seronegative child (odds ratio = 18.5, 95% CI = 2.3-146.5, attributable fraction = 58.3%). Five incident new cases of CRBBB were diagnosed after a 36-month follow-up of seropositive children who were enrolled in an independent clinical field trial. No case of frequent and/or multifocal ventricular premature beats was found in the cohort of children. The surprisingly high frequency of early ECG abnormalities, which indicates a rapid evolution from infection to disease, suggests the existence of endemic areas with a particular accelerated disease progression that was not described before. Under such conditions, a public health chemotherapy program focusing on the treatment of young seropositive children would be recommended.

Wolff-Parkinson-White syndrome and noncompaction in Leber's hereditary optic neuropathy due to the variant m.3460G>A.

PubMed

Finsterer, Josef; Stollberger, Claudia; Gatterer, Edmund

2018-05-01

This report describes a 66-year-old Caucasian male who acutely developed severe, bilateral impairment of visual acuity at 24 years of age. Leber's hereditary optic neuropathy (LHON) was suspected but the diagnosis was not genetically confirmed until the age of 49 years when the primary LHON mutation m.3460G>A was detected. Since onset, visual acuity had slightly improved. The family history was positive for LHON (brother, two sisters of mother, female cousin) and genetically confirmed in his brother and one aunt. Since the age of 65 years, he had experienced recurrent vertigo. His cardiological history was positive for arterial hypertension, noncompaction, myocardial thickening, intermittent right bundle-branch-block (RBBB) and Wolff-Parkinson-White (WPW) syndrome. In addition to LHON, he presented with polyneuropathy, hyperCKaemia, carotid artery occlusion, and a history of stroke. Cardiological investigations at 66 years of age revealed mildly reduced systolic function, enlarged atria, and nonsustained ventricular tachycardias. He underwent an electrophysiological investigation, but radiofrequency ablation was ruled out due to a 'bizarre' cardiac conduction system. Instead, an implantable cardioverter defibrillator was proposed but refused by the patient. Since the vertigo did not resolve it was attributed to polyneuropathy. This case demonstrates that LHON may be associated with noncompaction, myocardial thickening, reduced systolic function, enlarged atria, RBBB, WPW syndrome and nonsustained ventricular tachycardias. WPW syndrome in LHON may require invasive antiarrhythmic treatment.

Corneal confocal microscopy detects small fiber neuropathy in CMT1A patients

PubMed Central

Tavakoli, Mitra; Marshall, Andy; Banka, Siddharth; Petropoulos, Ioannis N; Fadavi, Hassan; Kingston, Helen; Malik, Rayaz A

2012-01-01

Although unmyelinated nerve fibers are affected in CMT1A, they have not been studied in detail due to the invasive nature of the techniques needed to study them. We established alterations in C-fiber bundles of the cornea in patients with CMT1A using non-invasive corneal confocal microscopy (CCM). Twelve patients with CMT1A and twelve healthy control subjects underwent assessment of neuropathic symptoms and deficits, electrophysiology, quantitative sensory testing, corneal sensitivity and corneal confocal microscopy. Corneal sensitivity, corneal nerve fiber density, corneal nerve branch density, corneal nerve fiber length and corneal nerve fiber tortuosity were significantly reduced in CMT1A patients compared to controls. There was a significant correlation between corneal sensation and CCM parameters with the severity of painful neuropathic symptoms, cold and warm thresholds and median nerve CMAP amplitude. CCM demonstrates significant damage to C-fiber bundles, which relates to some measures of neuropathy in CMT1A patients. PMID:22996176

Design and impact of bundled payment for detox and follow-up care.

PubMed

Quinn, Amity E; Hodgkin, Dominic; Perloff, Jennifer N; Stewart, Maureen T; Brolin, Mary; Lane, Nancy; Horgan, Constance M

2017-11-01

Recent payment reforms promote movement from fee-for-service to alternative payment models that shift financial risk from payers to providers, incentivizing providers to manage patients' utilization. Bundled payment, an episode-based fixed payment that includes the prices of a group of services that would typically treat an episode of care, is expanding in the United States. Bundled payment has been recommended as a way to pay for comprehensive SUD treatment and has the potential to improve treatment engagement after detox, which could reduce detox readmissions, improve health outcomes, and reduce medical care costs. However, if moving to bundled payment creates large losses for some providers, it may not be sustainable. The objective of this study was to design the first bundled payment for detox and follow-up care and to estimate its impact on provider revenues. Massachusetts Medicaid beneficiaries' behavioral health, medical, and pharmacy claims from July 2010-April 2013 were used to build and test a detox bundled payment for continuously enrolled adults (N=5521). A risk adjustment model was developed using general linear modeling to predict beneficiaries' episode costs. The projected payments to each provider from the risk adjustment analysis were compared to the observed baseline costs to determine the potential impact of a detox bundled payment reform on organizational revenues. This was modeled in two ways: first assuming no change in behavior and then assuming a supply-side cost sharing behavioral response of a 10% reduction in detox readmissions and an increase of one individual counseling and one group counseling session. The mean total 90-day detox episode cost was $3743. Nearly 70% of the total mean cost consists of the index detox, psychiatric inpatient care, and short-term residential care. Risk mitigation, including risk adjustment, substantially reduced the variation of the mean episode cost. There are opportunities for organizations to gain revenue under this bundled payment design, but many providers will lose money under a bundled payment designed using historic payment and costs. Designing a bundled payment for detox and follow-up care is feasible, but low case volume and the adequacy of the payment are concerns. Thus, a detox episode-based payment will likely be more challenging for smaller, independent SUD treatment providers. These providers are experiencing many changes as financing shifts away from block grant funding toward Medicaid funding. A detox bundled payment in practice would need to consider different risk mitigation strategies, provider pooling, and costs based on episodes of care meeting quality standards, but could incentivize care coordination, which is important to reducing detox readmissions and engaging patients in care. Copyright © 2017 Elsevier Inc. All rights reserved.

Hierarchical Nanostructures Self-Assembled from a Mixture System Containing Rod-Coil Block Copolymers and Rigid Homopolymers

PubMed Central

Li, Yongliang; Jiang, Tao; Lin, Shaoliang; Lin, Jiaping; Cai, Chunhua; Zhu, Xingyu

2015-01-01

Self-assembly behavior of a mixture system containing rod-coil block copolymers and rigid homopolymers was investigated by using Brownian dynamics simulations. The morphologies of formed hierarchical self-assemblies were found to be dependent on the Lennard-Jones (LJ) interaction εRR between rod blocks, lengths of rod and coil blocks in copolymer, and mixture ratio of block copolymers to homopolymers. As the εRR value decreases, the self-assembled structures of mixtures are transformed from an abacus-like structure to a helical structure, to a plain fiber, and finally are broken into unimers. The order parameter of rod blocks was calculated to confirm the structure transition. Through varying the length of rod and coil blocks, the regions of thermodynamic stability of abacus, helix, plain fiber, and unimers were mapped. Moreover, it was discovered that two levels of rod block ordering exist in the helices. The block copolymers are helically wrapped on the homopolymer bundles to form helical string, while the rod blocks are twistingly packed inside the string. In addition, the simulation results are in good agreement with experimental observations. The present work reveals the mechanism behind the formation of helical (experimentally super-helical) structures and may provide useful information for design and preparation of the complex structures. PMID:25965726

Geolocation error tracking of ZY-3 three line cameras

NASA Astrophysics Data System (ADS)

Pan, Hongbo

2017-01-01

The high-accuracy geolocation of high-resolution satellite images (HRSIs) is a key issue for mapping and integrating multi-temporal, multi-sensor images. In this manuscript, we propose a new geometric frame for analysing the geometric error of a stereo HRSI, in which the geolocation error can be divided into three parts: the epipolar direction, cross base direction, and height direction. With this frame, we proved that the height error of three line cameras (TLCs) is independent of nadir images, and that the terrain effect has a limited impact on the geolocation errors. For ZY-3 error sources, the drift error in both the pitch and roll angle and its influence on the geolocation accuracy are analysed. Epipolar and common tie-point constraints are proposed to study the bundle adjustment of HRSIs. Epipolar constraints explain that the relative orientation can reduce the number of compensation parameters in the cross base direction and have a limited impact on the height accuracy. The common tie points adjust the pitch-angle errors to be consistent with each other for TLCs. Therefore, free-net bundle adjustment of a single strip cannot significantly improve the geolocation accuracy. Furthermore, the epipolar and common tie-point constraints cause the error to propagate into the adjacent strip when multiple strips are involved in the bundle adjustment, which results in the same attitude uncertainty throughout the whole block. Two adjacent strips-Orbit 305 and Orbit 381, covering 7 and 12 standard scenes separately-and 308 ground control points (GCPs) were used for the experiments. The experiments validate the aforementioned theory. The planimetric and height root mean square errors were 2.09 and 1.28 m, respectively, when two GCPs were settled at the beginning and end of the block.

[Parahisian atrial tachycardia or atrioventricular nodal reentrant tachycardia with tendon of Todaro breakthrough?].

PubMed

Orczykowski, Michał; Jaworska-Wilczyńska, Maria; Urbanek, Piotr; Bodalski, Robert; Derejko, Paweł; Gajek, Jacek; Hryniewiecki, Tomasz; Szumowski, Lukasz; Walczak, Franciszek

2010-08-01

We present a case of a 61 year-old woman with tachycardia originating close to the His bundle where radiofrequency (RF) ablation may bear potential risk of atrioventricular (AV) block. In this case report we discuss the possibility of a AV nodal reciprocating tachycardia with tendon of Todaro breakthrough. Patient was safely and effectively treated with RF catheter ablation.

Quantitative Analysis of Filament Branch Orientation in Listeria Actin Comet Tails.

PubMed

Jasnin, Marion; Crevenna, Alvaro H

2016-02-23

Several bacterial and viral pathogens hijack the host actin cytoskeleton machinery to facilitate spread and infection. In particular, Listeria uses Arp2/3-mediated actin filament nucleation at the bacterial surface to generate a branched network that will help propel the bacteria. However, the mechanism of force generation remains elusive due to the lack of high-resolution three-dimensional structural data on the spatial organization of the actin mother and daughter (i.e., branch) filaments within this network. Here, we have explored the three-dimensional structure of Listeria actin tails in Xenopus laevis egg extracts using cryo-electron tomography. We found that the architecture of Listeria actin tails is shared between those formed in cells and in cell extracts. Both contained nanoscopic bundles along the plane of the substrate, where the bacterium lies, and upright filaments (also called Z filaments), both oriented tangentially to the bacterial cell wall. Here, we were able to identify actin filament intersections, which likely correspond to branches, within the tails. A quantitative analysis of putative Arp2/3-mediated branches in the actin network showed that mother filaments lie on the plane of the substrate, whereas daughter filaments have random deviations out of this plane. Moreover, the analysis revealed that branches are randomly oriented with respect to the bacterial surface. Therefore, the actin filament network does not push directly toward the surface but rather accumulates, building up stress around the Listeria surface. Our results favor a mechanism of force generation for Listeria movement where the stress is released into propulsive motion. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

[Pre- and post-orthotopic heart transplantation electrocardiogram characteristics of 998 patients].

PubMed

Guan, H Q; Chen, Z J; Zhou, Y; Liu, J; Sun, W X; Yuan, J; Liao, Y H; Dong, N G; Liu, J P; Feng, K G; Zhang, Q; Zhao, X; Qian, C; Hu, F

2017-04-24

Objective: To analyze pre- and post-operation electrocardiograms (ECGs) features of patients underwent orthotopic heart transplantation (OHT), and provide evidences for identifying and analyzing post OHT ECGs. Methods: Nine hundreds and ninty-eight pre- and post- OHT standard 12-leads ECGs from 110 consecutive patients, who underwent OHT in our hospital from May 2008 to May 2014, were analyzed. Results: The mean heart rate(HR)was (86.9±16.4) beats per minute before OHT, and (100.0±0.4) beats per minute after OHT. P wave's amplitude, duration, amplitude multiplied by duration of donor heart in lead Ⅱ were (0.124±0.069)mV, (111.1±17.2)ms, (14.34±9.51)mV·ms before OHT; (0.054±0.037)mV, (86.9±27.0)ms, (5.02±4.03)mV·ms at 1 month after OHT; (0.073±0.049)mV, (93.9±17.5) ms, (7.00±4.81)mV·ms at 6 years after OHT. ECGs rotation occurred in 83.64%(92/110) patients after OHT, and prevalence of clockwise rotation was 76.36%(84/110). Sinus tachycardia was evidenced in 99.09%(109/110) patients after OHT, and incomplete right bundle branch block was present in 60.91%(67/110) patients after OHT. Pseudo complete atrioventricular block mostly occurred at 2 days after OHT. Prevalence of double sinus rhythm was 27.95%(263/941) post OHT, 40% of them occurred between the 1st and the 2nd month post OHT; the atrial rate of recipient hearts was (104.0±10.2) beats per minucte between the 3rd and the 6th month post OHT, and was (95.3±4.2) beats per minucte between the 4th year and the 5th year. P wave's amplitude, duration, amplitude multiplied by duration of recipient heart in lead Ⅱ were (0.066±0.055) mV, (52.8±34.7) ms, (4.67±4.95) mV·ms at 1 month after OHT, (0.043±0.040)mV, (44.4±40.5) ms , (3.11±3.61) mV·ms between the 1st year and 2nd year after OHT. The absolute value of P-wave(originating from the donor heart) terminal force in chest leads increased in 48.99%(461/941) patients post OHT, the P-wave terminal force of V(1) , V(2) and V(3) were -0.044(-0.066, -0.028), -0.060(-0.087, -0.038), -0.035(-0.056, 0) mm·s. Notched P wave in chest leads was presented in 10.31%(97/941) patients post OHT. PR segment depression in chest leads occurred in 60.24%(100/166) patients between the 3rd month and the 6th month, the incidence of PR segment depression in V(1) , V(2) and V(3) was 21.04%(198/941), 37.41%(352/941) and 28.69%(270/941), respectively. Conclusions: OHT is related to significantly changed ECGs. The mean HR increased significantly after OHT, then decreased gradually after half a year to one year, but it was still higher than preoperative mean HR after five or six years; the P waves of donor heart were usually inconspicuous or small in first month after OHT, and they became bigger after 2 months, and their duration and amplitude then became relatively steady afterwards. ECGs rotation, especially the clockwise rotation, was common post OHT. A variety of arrhythmias originating from the donor heart including sinus tachycardia and incomplete right bundle branch block could be found. Pseudo complete atrioventricular block could also be found in the early phase after OHT. With the extension of time, the incidence of double sinus rhythm reduced gradually. The atrial rate and P wave of recipient heart presented with a tendency to become lower. The absolute value of P-waves(originating from the donor heart) terminal force in chest leads (mainly V(1), V(2) and V(3)) increased, notched P waves in chest leads (mainly V(1), V(2)) and PR segments depression in chest leads (mainly V(2), V(3) and V(4)) also belong to typical post OHT ECGs features.

Supplemental branched-chain amino acids improve performance and immune response of newly-received feedlot calves

USDA-ARS?s Scientific Manuscript database

Supplemental branched-chain AA (BCAA) improved N balance of steers during a simulated pathogen challenge. The objective of this study was to determine the effect of supplemental BCAA on growth and health of newly-received feedlot steers. Steers (n = 120; initial BW = 376 ± 5 kg) were blocked by BW a...

A simple theory of molecular organization in fullerene-containing liquid crystals

NASA Astrophysics Data System (ADS)

Peroukidis, S. D.; Vanakaras, A. G.; Photinos, D. J.

2005-10-01

Systematic efforts to synthesize fullerene-containing liquid crystals have produced a variety of successful model compounds. We present a simple molecular theory, based on the interconverting shape approach [Vanakaras and Photinos, J. Mater. Chem. 15, 2002 (2005)], that relates the self-organization observed in these systems to their molecular structure. The interactions are modeled by dividing each molecule into a number of submolecular blocks to which specific interactions are assigned. Three types of blocks are introduced, corresponding to fullerene units, mesogenic units, and nonmesogenic linkage units. The blocks are constrained to move on a cubic three-dimensional lattice and molecular flexibility is allowed by retaining a number of representative conformations within the block representation of the molecule. Calculations are presented for a variety of molecular architectures including twin mesogenic branch monoadducts of C60, twin dendromesogenic branch monoadducts, and conical (badminton shuttlecock) multiadducts of C60. The dependence of the phase diagrams on the interaction parameters is explored. In spite of its many simplifications and the minimal molecular modeling used (three types of chemically distinct submolecular blocks with only repulsive interactions), the theory accounts remarkably well for the phase behavior of these systems.

Low-cost grass restoration using erosion barriers in a degraded African rangeland

USGS Publications Warehouse

Kimiti, David W; Riginos, Corinna; Belnap, Jayne

2017-01-01

Rangeland degradation, typified by extensive bare ground and soil erosion, is a serious problem around the world. In sub-Saharan Africa, rangeland degradation threatens the food security of millions of people who depend on livestock and the region's large mammalian wildlife diversity. We tested the ability of five simple, low-cost erosion barriers to promote grass and forb establishment in a bare ground-dominated rangeland in Kenya. These treatments were: (1) trenches with small berms; (2) bundles of branches; and bundles of branches with (3) elephant dung balls, (4) burlap sacking, or (5) nylon mesh sacking inside them. We also tested whether barrier performance depended on (1) supplemental seeding with the grass Cenchrus ciliaris and (2) whether a barrier was located next to existing vegetation patches versus in the open. Within months, the trench and nylon mesh barriers had accumulated 20–50% more sediment than other treatments and had greater grass and forb seedling establishment. Seeding with Cenchrusresulted in higher herbaceous cover but was not necessary for other grasses to establish. After 3 years, the trench and nylon mesh barriers had created patches of new vegetation averaging 18–63% larger than patches created by the other treatments. Barriers that were initially adjacent to existing vegetation had created new vegetation patches averaging 65% larger than those created by solitary barriers. Results suggest that all barrier types increase grass cover but that trenches—especially if placed next to existing vegetation patches—are a particularly cost-effective way to reduce bare ground and erosion in degraded rangelands.

The control of fruiting body formation in the ascomycete Sordaria macrospora Auersw. by regulation of hyphal development : An analysis based on scanning electron and light microscopic observations.

PubMed

Hock, B; Bahn, M; Walk, R A; Nitschke, U

1978-01-01

The morphological effects of biotin and L-arginine on fruiting body formation of the ascomycete Sordaria macrospora are investigated by scanning electron and light microscopy. Biotin is recognized as an elongation factor and arginine as a branching factor in vegetative and reproductive hyphae. In the absence of exogenous biotin, development is blocked after the ascogonium-core hypha stage of protoperithecial morphogenesis, whereas linear growth of the myceliar front is maintained. The addition of exogenous arginine to a biotin deficient culture induces the formation of numerous side branches even in the older mycelium. Fruiting body formation, however, remains blocked at the protoperithecial stage as before, because of the inability of the side branches to elongate. When biotin and arginine are administered simultaneously, a most vigorous branching and growth are induced in the older mycelium, accompanied by a rapid and maximal formation of fruiting bodies. The results are summarized in a model of the exogenous control of hyphal morphogenesis. The model is designed to explain the relationship between fruiting and hyphal density as well as the edge effect on fruiting body formation.

Manipulation of partially oriented hydroxyapatite building blocks to form flowerlike bundles without acid-base regulation.

PubMed

Wen, Zhenliang; Wang, Zihao; Chen, Jingdi; Zhong, Shengnan; Hu, Yimin; Wang, Jianhua; Zhang, Qiqing

2016-06-01

The application of hydroxyapatite (HAP) in different fields depends greatly on its morphology, composition and structure. Besides, the main inorganic building blocks of human bones and teeth are also HAP. Therefore, accurate shape and aggregation control and of hydroxyapatite particles will be of great interest. Herein, oriented bundles of flowerlike HAP nanorods were successfully prepared through hydrothermal treatment without acid-base regulation, with the mono-alkyl phosphate (MAP) and sodium citrate as surfactant and chelating agent, respectively. The prepared samples were characterized by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and zeta potential, the pH value and conductivity value of suspension were characterized by pH meter and conductivity measurement. The results showed that the MAP and citrate play an important role in assembly of HAP nanorods without acid-base regulation. Citrate calcium complex could decompose slowly and release citrate ions at hydrothermal conditions. Besides, the further decomposition of citrate ions could release aconitic acid as the reaction time prolongs. Moreover, the possible scheme for the formation process was discussed in detail. Copyright © 2016 Elsevier B.V. All rights reserved.

[Regional nerve block in facial surgery].

PubMed

Gramkow, Christina; Sørensen, Jesper

2008-02-11

Regional nerve blocking techniques offer a suitable alternative to local infiltration anaesthesia for facial soft tissue-surgery. Moreover, they present several advantages over general anaesthesia, including smoother recovery, fewer side effects, residual analgesia into the postoperative period, earlier discharge from the recovery room and reduced costs. The branches of the trigeminal nerve and the sensory nerves originating from the upper cervical plexus can be targeted at several anatomical locations. We summarize current knowledge on facial nerve block techniques and recommend ten nerve blocks providing efficient anaesthesia for the entire head and upper-neck region.

The Vehicle Control Systems Branch at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Barret, Chris

1990-01-01

This paper outlines the responsibility of the Vehicle Control Systems Branch at the Marshall Space Flight Center (MSFC) to analyze, evaluate, define, design, verify, and specify requirements for advanced launch vehicles and related space projects, and to conduct research in advanced flight control concepts. Attention is given to branch responsibilities which include Shuttle-C, Shuttle-C Block II, Shuttle-Z, lunar cargo launch vehicles, Mars cargo launch vehicles, orbital maneuvering vehicle, automatic docking, tethered satellite, aeroassisted flight experiment, and solid rocket booster parachute recovery system design.

Engineered short branched-chain acyl-CoA synthesis in E. coli and acylation of chloramphenicol to branched-chain derivatives.

PubMed

Bi, Huiping; Bai, Yanfen; Cai, Tao; Zhuang, Yibin; Liang, Xiaomei; Zhang, Xueli; Liu, Tao; Ma, Yanhe

2013-12-01

Short branched-chain acyl-CoAs are important building blocks for a wide variety of pharmaceutically valuable natural products. Escherichia coli has been used as a heterologous host for the production of a variety of natural compounds for many years. In the current study, we engineered synthesis of isobutyryl-CoA and isovaleryl-CoA from glucose in E. coli by integration of the branched-chain α-keto acid dehydrogenase complex from Streptomyces avermitilis. In the presence of the chloramphenicol acetyltransferase (cat) gene, chloramphenicol was converted to both chloramphenicol-3-isobutyrate and chloramphenicol-3-isovalerate by the recombinant E. coli strains, which suggested successful synthesis of isobutyryl-CoA and isovaleryl-CoA. Furthermore, we improved the α-keto acid precursor supply by overexpressing the alsS gene from Bacillus subtilis and the ilvC and ilvD genes from E. coli and thus enhanced the synthesis of short branched-chain acyl-CoAs. By feeding 25 mg/L chloramphenicol, 2.96 ± 0.06 mg/L chloramphenicol-3-isobutyrate and 3.94 ± 0.06 mg/L chloramphenicol-3-isovalerate were generated by the engineered E. coli strain, which indicated efficient biosynthesis of short branched-chain acyl-CoAs. HPLC analysis showed that the most efficient E. coli strain produced 80.77 ± 3.83 nmol/g wet weight isovaleryl-CoA. To our knowledge, this is the first report of production of short branched-chain acyl-CoAs in E. coli and opens a way to biosynthesize various valuable natural compounds based on these special building blocks from renewable carbon sources.

Electrocardiographic and echocardiographic abnormalities in Chagas disease: findings in residents of rural Bolivian communities hyperendemic for Chagas disease.

PubMed

Fernandez, Antonio B; Nunes, Maria Carmo P; Clark, Eva H; Samuels, Aaron; Menacho, Silvio; Gomez, Jesus; Bozo Gutierrez, Ricardo W; Crawford, Thomas C; Gilman, Robert H; Bern, Caryn

2015-09-01

Chagas disease is a neglected and preventable tropical disease that causes significant cardiac morbidity and mortality in Latin America. This study sought to describe cardiac findings among inhabitants of rural communities of the Bolivian Chaco. The cardiac study drew participants from an epidemiologic study in 7 indigenous Guarani communities. All infected participants 10 years or older were asked to undergo a brief physical examination and 12-lead electrocardiogram (ECG). A subset had echocardiograms. ECG and echocardiograms were read by 1 or more cardiologists. Of 1,137 residents 10 years or older, 753 (66.2%) had Trypanosoma cruzi infection. Cardiac evaluations were performed for 398 infected participants 10 years or older. Fifty-five participants (13.8%) had 1 or more ECG abnormalities suggestive of Chagas cardiomyopathy. The most frequent abnormalities were bundle branch blocks in 42 (11.3%), followed by rhythm disturbances or ventricular ectopy in 13 (3.3%), and atrioventricular blocks (AVB) in 10 participants (2.6%). The prevalence of any abnormality rose from 1.1% among those 10 to 19 years old to 14.2%, 17.3%, and 26.4% among those 20 to 39, 40 to 59, and older than 60 years, respectively. First-degree AVB was seen most frequently in participants 60 years or older, but the 4 patients with third-degree AVB were all under 50 years old. Eighteen and 2 participants had a left ventricular ejection fraction of 40% to 54% and <40%, respectively. An increasing number of ECG abnormalities was associated with progressively larger left ventricular end-diastolic dimensions and lower left ventricular ejection fraction. We found a high prevalence of ECG abnormalities and substantial evidence of Chagas cardiomyopathy. Programs to improve access to basic cardiac care (annual ECG, antiarrhythmics, pacemakers) could have an immediate impact on morbidity and mortality in these highly endemic communities. Copyright © 2015 World Heart Federation (Geneva). All rights reserved.

Conduction Abnormalities and Pacemaker Implantations After SAPIEN 3 Vs SAPIEN XT Prosthesis Aortic Valve Implantation.

PubMed

Husser, Oliver; Kessler, Thorsten; Burgdorf, Christof; Templin, Christian; Pellegrini, Costanza; Schneider, Simon; Kasel, Albert Markus; Kastrati, Adnan; Schunkert, Heribert; Hengstenberg, Christian

2016-02-01

Transcatheter aortic valve implantation is increasingly used in patients with aortic stenosis. Post-procedural intraventricular conduction abnormalities and permanent pacemaker implantations remain a serious concern. Recently, the Edwards SAPIEN 3 prosthesis has replaced the SAPIEN XT. We sought to determine the incidences of new-onset intraventricular conduction abnormalities and permanent pacemaker implantations by comparing the 2 devices. We analyzed the last consecutive 103 patients undergoing transcatheter aortic valve implantation with SAPIEN XT before SAPIEN 3 was used in the next 105 patients. To analyze permanent pacemaker implantations and new-onset intraventricular conduction abnormalities, patients with these conditions at baseline were excluded. Electrocardiograms were recorded at baseline, after the procedure, and before discharge. SAPIEN 3 was associated with higher device success (100% vs 92%; P=.005) and less paravalvular leakage (0% vs 7%; P<.001). The incidence of permanent pacemaker implantations was 12.6% (23 of 183) with no difference between the 2 groups (SAPIEN 3: 12.5% [12 of 96] vs SAPIEN XT: 12.6% [11 of 87]; P=.99). SAPIEN 3 was associated with a higher rate of new-onset intraventricular conduction abnormalities (49% vs 27%; P=.007) due to a higher rate of fascicular blocks (17% vs 5%; P=.021). There was no statistically significant difference in transient (29% [20 of 69] vs persistent 19% [12 of 64]; P=.168) left bundle branch blocks (28% [19 of 69] vs 17% [11 of 64]; P=.154) when SAPIEN 3 was compared with SAPIEN XT. We found a trend toward a higher rate of new-onset intraventricular conduction abnormalities with SAPIEN 3 compared with SAPIEN XT, although this did not result in a higher permanent pacemaker implantation rate. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Structure of clusters and building blocks in amylopectin from African rice accessions.

PubMed

Gayin, Joseph; Abdel-Aal, El-Sayed M; Marcone, Massimo; Manful, John; Bertoft, Eric

2016-09-05

Enzymatic hydrolysis in combination with gel-permeation and anion-exchange chromatography techniques were employed to characterise the composition of clusters and building blocks of amylopectin from two African rice (Oryza glaberrima) accessions-IRGC 103759 and TOG 12440. The samples were compared with one Asian rice (Oryza sativa) sample (cv WITA 4) and one O. sativa×O. glaberrima cross (NERICA 4). The average DP of clusters from the African rice accessions (ARAs) was marginally larger (DP=83) than in WITA 4 (DP=81). However, regarding average number of chains, clusters from the ARAs represented both the smallest and largest clusters. Overall, the result suggested that the structure of clusters in TOG 12440 was dense with short chains and high degree of branching, whereas the situation was the opposite in NERICA 4. IRGC 103759 and WITA 4 possessed clusters with intermediate characteristics. The commonest type of building blocks in all samples was group 2 (single branched dextrins) representing 40.3-49.4% of the blocks, while groups 3-6 were found in successively lower numbers. The average number of building blocks in the clusters was significantly larger in NERICA 4 (5.8) and WITA 4 (5.7) than in IRGC 103759 and TOG 12440 (5.1 and 5.3, respectively). Copyright © 2016 Elsevier Ltd. All rights reserved.

Rod-Coil Block Polyimide Copolymers

NASA Technical Reports Server (NTRS)

Meador, Mary Ann B. (Inventor); Kinder, James D. (Inventor)

2005-01-01

This invention is a series of rod-coil block polyimide copolymers that are easy to fabricate into mechanically resilient films with acceptable ionic or protonic conductivity at a variety of temperatures. The copolymers consist of short-rigid polyimide rod segments alternating with polyether coil segments. The rods and coil segments can be linear, branched or mixtures of linear and branched segments. The highly incompatible rods and coil segments phase separate, providing nanoscale channels for ion conduction. The polyimide segments provide dimensional and mechanical stability and can be functionalized in a number of ways to provide specialized functions for a given application. These rod-coil black polyimide copolymers are particularly useful in the preparation of ion conductive membranes for use in the manufacture of fuel cells and lithium based polymer batteries.

Protocol for a Delay-Tolerant Data-Communication Network

NASA Technical Reports Server (NTRS)

Torgerson, Jordan; Hooke, Adrian; Burleigh, Scott; Fall, Kevin

2004-01-01

As its name partly indicates, the Delay-Tolerant Networking (DTN) Bundle Protocol is a protocol for delay-tolerant transmission of data via communication networks. This protocol was conceived as a result of studies of how to adapt Internet protocols so that Internet-like services could be provided across interplanetary distances in support of deep-space exploration. The protocol, and software to implement the protocol, is being developed in collaboration among experts at NASA's Jet Propulsion Laboratory and other institutions. No current Internet protocols can accommodate long transmission delay times or intermittent link connectivity. The DTN Bundle Protocol represents a departure from the standard Internet assumption that a continuous path is available from a host computer to a client computer: It provides for routing of data through networks that may be disjointed and may be characterized by long transmission delays. In addition to networks that include deepspace communication links, examples of such networks include terrestrial ones within which branches are temporarily disconnected. The protocol is based partly on the definition of a message-based overlay above the transport layers of the networks on which it is hosted.

Efficiency of timing delays and electrode positions in optimization of biventricular pacing: a simulation study.

PubMed

Miri, Raz; Graf, Iulia M; Dössel, Olaf

2009-11-01

Electrode positions and timing delays influence the efficacy of biventricular pacing (BVP). Accordingly, this study focuses on BVP optimization, using a detailed 3-D electrophysiological model of the human heart, which is adapted to patient-specific anatomy and pathophysiology. The research is effectuated on ten heart models with left bundle branch block and myocardial infarction derived from magnetic resonance and computed tomography data. Cardiac electrical activity is simulated with the ten Tusscher cell model and adaptive cellular automaton at physiological and pathological conduction levels. The optimization methods are based on a comparison between the electrical response of the healthy and diseased heart models, measured in terms of root mean square error (E(RMS)) of the excitation front and the QRS duration error (E(QRS)). Intra- and intermethod associations of the pacing electrodes and timing delays variables were analyzed with statistical methods, i.e., t -test for dependent data, one-way analysis of variance for electrode pairs, and Pearson model for equivalent parameters from the two optimization methods. The results indicate that lateral the left ventricle and the upper or middle septal area are frequently (60% of cases) the optimal positions of the left and right electrodes, respectively. Statistical analysis proves that the two optimization methods are in good agreement. In conclusion, a noninvasive preoperative BVP optimization strategy based on computer simulations can be used to identify the most beneficial patient-specific electrode configuration and timing delays.

Epicardial left ventricular lead placement for cardiac resynchronization therapy: optimal pace site selection with pressure-volume loops.

PubMed

Dekker, A L A J; Phelps, B; Dijkman, B; van der Nagel, T; van der Veen, F H; Geskes, G G; Maessen, J G

2004-06-01

Patients in heart failure with left bundle branch block benefit from cardiac resynchronization therapy. Usually the left ventricular pacing lead is placed by coronary sinus catheterization; however, this procedure is not always successful, and patients may be referred for surgical epicardial lead placement. The objective of this study was to develop a method to guide epicardial lead placement in cardiac resynchronization therapy. Eleven patients in heart failure who were eligible for cardiac resynchronization therapy were referred for surgery because of failed coronary sinus left ventricular lead implantation. Minithoracotomy or thoracoscopy was performed, and a temporary epicardial electrode was used for biventricular pacing at various sites on the left ventricle. Pressure-volume loops with the conductance catheter were used to select the best site for each individual patient. Relative to the baseline situation, biventricular pacing with an optimal left ventricular lead position significantly increased stroke volume (+39%, P =.01), maximal left ventricular pressure derivative (+20%, P =.02), ejection fraction (+30%, P =.007), and stroke work (+66%, P =.006) and reduced end-systolic volume (-6%, P =.04). In contrast, biventricular pacing at a suboptimal site did not significantly change left ventricular function and even worsened it in some cases. To optimize cardiac resynchronization therapy with epicardial leads, mapping to determine the best pace site is a prerequisite. Pressure-volume loops offer real-time guidance for targeting epicardial lead placement during minimal invasive surgery.

Evaluation of left ventricular function by bedside ultrasound in acute toxic myocarditis.

PubMed

Brown, Cara; Budhram, Gavin

2013-10-01

Myocarditis can be difficult to diagnose in the Emergency Department (ED) due to the lack of classic symptoms and the wide variation in presentations. Poor cardiac contractility is a common finding in myocarditis and can be evaluated by bedside ultrasound. To demonstrate the utility of fractional shortening measurements as an estimation of left ventricular function during bedside cardiac ultrasound evaluation in the ED. A 54-year-old man presented to the ED complaining of 3 days of chest tightness, palpitations, and dyspnea, as well as persistent abdominal pain and vomiting. An electrocardiogram (ECG) showed sinus tachycardia with presumably new ST-segment elevation and signs of an incomplete right bundle branch block. A bedside echocardiogram was performed by the emergency physician that showed poor left ventricular function by endocardial fractional shortening measurements. On further questioning, the patient revealed that for the past 2 weeks he had been regularly huffing a commercially available compressed air duster. Based on these history and examination findings, the patient was given a presumptive diagnosis of toxic myocarditis. A follow-up echocardiogram approximately 7 weeks later demonstrated resolution of the left ventricular systolic dysfunction and his ECG findings normalized. Cardiac ultrasound findings of severely reduced global function measured by endocardial fractional shortening were seen in this patient and supported the diagnosis of myocarditis. Endocardial fractional shortening is a useful means of easily evaluating and documenting left ventricular function and can be performed at the bedside in the ED. Copyright © 2013 Elsevier Inc. All rights reserved.

Depression, psychological distress, and quality of life in patients with cardioverter defibrillator with or without cardiac resynchronization therapy.

PubMed

Knackstedt, Christian; Arndt, Marlies; Mischke, Karl; Marx, Nikolaus; Nieman, Fred; Kunert, Hanns Jürgen; Schauerte, Patrick; Norra, Christine

2014-05-01

Congestive heart failure is frequent and leads to reduced exercise capacity, reduced quality of life (QoL), and depression in many patients. Cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillators (ICD) offer therapeutic options and may have an impact on QoL and depression. This study was performed to evaluate physical and mental health in patients undergoing ICD or combined CRT/ICD-implantation (CRT-D). Echocardiography, spiroergometry, and psychometric questionnaires [Beck Depression Inventory, General World Health Organization Five Well-being Index (WHO-5), Brief Symptom Inventory and 36-item Short Form (SF-36)] were obtained in 39 patients (ICD: 17, CRT-D: 22) at baseline and 6-month follow-up (FU) after device implantation. CRT-D patients had a higher NYHA class and broader left bundle branch block than ICD patients at baseline. At FU, ejection fraction (EF), peak oxygen uptake, and NYHA class improved significantly in CRT-D patients but remained unchanged in ICD patients. Patients with CRT-D implantation showed higher levels of depressive symptoms, psychological distress, and impairment in QoL at baseline and FU compared to ICD patients. These impairments remained mostly unchanged in all patients after 6 months. Overall, these findings imply that there is a need for careful assessment and treatment of psychological distress and depression in ICD and CRT-D patients in the course of device implantation as psychological burden seems to persist irrespective of physical improvement.

Sudden visual loss after cardiac resynchronization therapy device implantation.

PubMed

De Vitis, Luigi A; Marchese, Alessandro; Giuffrè, Chiara; Carnevali, Adriano; Querques, Lea; Tomasso, Livia; Baldin, Giovanni; Maestranzi, Gisella; Lattanzio, Rosangela; Querques, Giuseppe; Bandello, Francesco

2017-03-10

To report a case of sudden decrease in visual acuity possibly due to a cardiogenic embolism in a patient who underwent cardiac resynchronization therapy (CRT) device implantation. A 62-year-old man with severe left ventricular systolic dysfunction and a left bundle branch block was referred to our department because of a sudden decrease in visual acuity. Nine days earlier, he had undergone cardiac transapical implantation of a CRT device, which was followed, 2 days later, by an inflammatory reaction. The patient underwent several general and ophthalmologic examinations, including multimodal imaging. At presentation, right eye (RE) best-corrected visual acuity (BCVA) was counting fingers and RE pupil was hyporeactive. Fundus examination revealed white-centered hemorrhagic dots suggestive of Roth spots. Fluorescein angiography showed delay in vascular perfusion during early stage, late hyperfluorescence of the macula and optic disk, and peripheral perivascular leakage. The first visual field test showed complete loss of vision RE and a normal left eye. Due to suspected giant cell arteritis, temporal artery biopsy was performed. Thirty minutes after the procedure, an ischemic stroke with right hemisyndrome and aphasia occurred. The RE BCVA worsened to hands motion. Four months later, RE BCVA did not improve, despite improvement in fluorescein angiography inflammatory sign. We report a possible cardiogenic embolism secondary to undiagnosed infective endocarditis causing monocular visual loss after CRT device implantation. It remains unclear how the embolus caused severe functional damage without altering the retinal anatomical structure.

[A case of Leigh syndrome associated with respiratory chain complex I deficiency due to mitochondrial gene 13513G>A mutation].

PubMed

Wei, Xiao-Qiong; Kong, Qing-Peng; Zhang, Yao; Yang, Yan-Ling; Chang, Xing-Zhi; Qi, Yu; Qi, Zhao-Yue; Xiao, Jiang-Xi; Qin, Jiong; Wu, Xi-Ru

2009-05-01

Leigh syndrome is a genetically heterogeneous disease caused by defects in enzymes involved in aerobic energy metabolism and the Krebs', cycle. Mitonchondrial complex I deficiency is a main cause of Leigh syndrome. In this study, a Chinese child with Leigh syndrome caused by 13513G>A mutation was reported. The proband was the first child of his parents. The previously healthy boy presented with generalized epilepsy at 12 years of age. When he visited Peking University First Hospital at 13 years of age, he had subacute loss of vision in two eyes and temporal defect of visual field in the left eye. He walked with a spastic gait. His blood lactate and pyruvate levels were elevated. Muscle biopsy showed mild lipid accumulation in muscle fiber. An electrocardiogram showed incomplete right bundle branch block. Brain magnetic resonance imaging showed bilateral, symmetrical lesions in the basal ganglia, supporting the diagnosis of Leigh syndrome. 13513G>A mutation was identified by gene analysis in the patient, which led to mitochondrial respiratory chain complex I deficiency. Multivitamins and L-carnitine were administered. At present, the patient is 16 years old and has progressive deterioration with significant muscle weakness and body weight loss. He is absent from school. He has no obvious retardation in intelligence. 13513G>A mutation was first identified by gene analysis in Chinese population with Leigh syndrome. This may be helpful in genetic counseling.

Arrhythmia-induced cardiomyopathies: the riddle of the chicken and the egg still unanswered?

PubMed

Simantirakis, Emmanuel N; Koutalas, Emmanuel P; Vardas, Panos E

2012-04-01

The hypothesis testing of inappropriate fast, irregular, or asynchronous myocardial contraction provoking cardiomyopathy has been the primary focus of numerous research efforts, especially during the last few decades. Rapid ventricular rates resulting from supraventricular arrhythmias and atrial fibrillation (AF), irregularity of heart rhythm-basic element of AF-and asynchrony, as a consequence of right ventricular pacing, bundle branch block, or frequent premature ventricular complexes, have been established as primary causes of arrhythmia-induced cardiomyopathy. The main pathophysiological pathways involved have been clarified, including neurohumoral activation, energy stores depletion, and abnormalities in stress and strain. Unfortunately, from a clinical point of view, patients usually seek medical advice only when symptoms develop, while the causative arrhythmia may be present for months or years, resulting in myocardial remodelling, diastolic, and systolic dysfunction. In some cases, making a definite diagnosis may become a strenuous exercise for the treating physician, as the arrhythmia may not be present and, additionally, therapy must be applied for the diagnosis to be confirmed retrospectively. The diagnostic process is also hardened due to the fact that strict diagnosing criteria are still a matter of discrepancy. Therapy options include pharmaceutical agents trials, catheter-based therapies and, in the context of chronic ventricular pacing, resynchronization. For the majority of patients, partial or complete recovery is expected, although they have to be followed up thoroughly due to the risk of recurrence. Large, randomized controlled trials are more than necessary to optimize patients' stratification and therapeutic strategy choices.

ELECTROCARDIOGRAPHIC ABNORMALITIES AMONG MEXICAN AMERICANS: CORRELATIONS WITH DIABETES, OBESITY, AND THE METABOLIC SYNDROME.

PubMed

Queen, Saulette R; Smulevitz, Beverly; Rentfro, Anne R; Vatcheva, Kristina P; Kim, Hyunggun; McPherson, David D; Hanis, Craig L; Fisher-Hoch, Susan P; McCormick, Joseph B; Laing, Susan T

2012-04-01

Resting ischemic electrocardiographic abnormalities have been associated with cardiovascular mortality. Simple markers of abnormal autonomic tone have also been associated with diabetes, obesity, and the metabolic syndrome in some populations. Data on these electrocardiographic abnormalities and correlations with coronary risk factors are lacking among Mexican Americans wherein these conditions are prevalent. This study aimed to evaluate the prevalent resting electrocardiographic abnormalities among community-dwelling Mexican Americans, and correlate these findings with coronary risk factors, particularly diabetes, obesity, and the metabolic syndrome. Study subjects (n=1280) were drawn from the Cameron County Hispanic Cohort comprised of community-dwelling Mexican Americans living in Brownsville, Texas at the United States-Mexico border. Ischemic electrocardiographic abnormalities were defined as presence of ST/T wave abnormalities suggestive of ischemia, abnormal Q waves, and left bundle branch block. Parameters that reflect autonomic tone, such as heart rate-corrected QT interval and resting heart rate, were also measured. Ischemic electrocardiographic abnormalities were more prevalent among older persons and those with hypertension, diabetes, obesity, and the metabolic syndrome. Subjects in the highest quartiles of QTc interval and resting heart rate were also more likely to be diabetic, hypertensive, obese, or have the metabolic syndrome. Among Mexican Americans, persons with diabetes, obesity, and the metabolic syndrome were more likely to have ischemic electrocardiographic abnormalities, longer QTc intervals, and higher resting heart rates. A resting electrocardiogram can play a complementary role in the comprehensive evaluation of cardiovascular risk in this minority population.

T wave amplitude in lead aVR as a novel diagnostic marker for cardiac sarcoidosis.

PubMed

Tanaka, Yoshihiro; Konno, Tetsuo; Yoshida, Shohei; Tsuda, Toyonobu; Sakata, Kenji; Furusho, Hiroshi; Takamura, Masayuki; Yoshimura, Kenichi; Yamagishi, Masakazu; Hayashi, Kenshi

2017-03-01

It is vital to identify cardiac involvement (CI) in patients with sarcoidosis as the condition could initially lead to sudden cardiac death. Although the T wave amplitude in lead aVR (TWAaVR) is reportedly associated with adverse cardiac events in various cardiovascular diseases, only scarce data are available concerning the utility of lead aVR in identifying CI in patients with sarcoidosis. We retrospectively investigated the diagnostic values of TWAaVR in patients with sarcoidosis in comparison with conventional electrocardiography parameters such as bundle branch block (BBB). From January 2006 to December 2014, 93 consecutive patients with sarcoidosis were enrolled (mean age, 55.7 ± 15.7 years; male, 31 %; cardiac involvement, n = 26). TWAaVR showed the greatest sensitivity (39 %) and specificity (92 %) in distinguishing between sarcoidosis patients with and without CI, at a cutoff value of -0.08 mV. The diagnostic value of BBB for cardiac involvement was significantly improved when combined with TWAaVR (sensitivity: 61-94 %, specificity: 97-89 %, area under the curve: 0.79-0.92, p = 0.018). Multivariate logistic regression analysis indicated that TWAaVR and BBB were independent electrocardiography parameters associated with CI. In summary, we observed that sarcoidosis patients exhibiting a high TWAaVR were likely to have CI. Thus, the application of a combination of BBB with TWAaVR may be useful when screening for CI in sarcoidosis patients.

Spatiotemporal Characteristics of QRS Complexes Enable the Diagnosis of Brugada Syndrome Regardless of the Appearance of a Type 1 ECG.

PubMed

Guillem, Maria S; Climent, Andreu M; Millet, José; Berne, Paola; Ramos, Rafael; Brugada, Josep; Brugada, Ramon

2016-05-01

The diagnosis of Brugada syndrome based on the ECG is hampered by the dynamic nature of its ECG manifestations. Brugada syndrome patients are only 25% likely to present a type 1 ECG. The objective of this study is to provide an ECG diagnostic criterion for Brugada syndrome patients that can be applied consistently even in the absence of a type 1 ECG. We recorded 67-lead body surface potential maps from 94 Brugada syndrome patients and 82 controls (including right bundle branch block patients and healthy individuals). The spatial propagation direction during the last r' wave and the slope at the end of the QRS complex were measured and compared between patients groups. Receiver-operating characteristic curves were constructed for half of the database to identify optimal cutoff values; sensitivity and specificity for these cutoff values were measured in the other half of the database. A spontaneous type 1 ECG was present in only 30% of BrS patients. An orientation in the sagittal plane < 101º during the last r' wave and a descending slope < 9.65 mV/s enables the diagnosis of the syndrome with a sensitivity of 69% and a specificity of 97% in non-type 1 Brugada syndrome patients. Spatiotemporal characteristics of surface ECG recordings can enable a robust identification of BrS even without the presence of a type 1 ECG. © 2016 Wiley Periodicals, Inc.

Intravascular migration of a broken cerclage wire into the left heart.

PubMed

Leonardi, Francesco; Rivera, Fabrizio

2014-10-01

This article describes a patient in whom a broken cerclage wire migrated from the left hip into the left ventricle. A 71-year-old woman was admitted to the authors' hospital for preoperative examination before femoral hernia repair. Chest radiograph showed a metallic wire in the left ventricle. Twenty-four years earlier, she had a revision arthroplasty. During revision surgery, fragments of the osteotomy were fixed to the femur with multiple cerclage wires. During the past 5 years, radiographic follow-up showed progressive multiple ruptures of cerclage wires. The cerclage wiring was not removed because the patient had no related clinical symptoms. Radiograph of the left hip showed a well-fixed cemented acetabular ring and an uncemented femoral stem with a healed trochanteric osteotomy. All cerclage wires were broken into multiple parts, and it was very difficult to determine which part had migrated into the heart. Thoracic computed tomography scan showed wire that had migrated into the anterior left ventricular myocardial wall at the atrioventricular level. The patient had no clinical symptoms. Electrocardiogram showed a normal sinus rhythm and right bundle branch block. Because of the high risk of surgical left ventriculotomy associated with searching for wire that had migrated into the myocardial wall, patient monitoring was planned. Definitive management of this complication constitutes a dilemma. Although this complication is highly unusual, the possibility of intracardiac migration of broken wire should be considered when deciding on prophylactic surgical removal of hardware after fracture or osteotomy healing. Copyright 2014, SLACK Incorporated.

Symplasmic transport and phloem loading in gymnosperm leaves

PubMed Central

Liesche, Johannes; Martens, Helle Juel

2010-01-01

Despite more than 130 years of research, phloem loading is far from being understood in gymnosperms. In part this is due to the special architecture of their leaves. They differ from angiosperm leaves among others by having a transfusion tissue between bundle sheath and the axial vascular elements. This article reviews the somewhat inaccessible and/or neglected literature and identifies the key points for pre-phloem transport and loading of photoassimilates. The pre-phloem pathway of assimilates is structurally characterized by a high number of plasmodesmata between all cell types starting in the mesophyll and continuing via bundle sheath, transfusion parenchyma, Strasburger cells up to the sieve elements. Occurrence of median cavities and branching indicates that primary plasmodesmata get secondarily modified and multiplied during expansion growth. Only functional tests can elucidate whether this symplasmic pathway is indeed continuous for assimilates, and if phloem loading in gymnosperms is comparable with the symplasmic loading mode in many angiosperm trees. In contrast to angiosperms, the bundle sheath has properties of an endodermis and is equipped with Casparian strips or other wall modifications that form a domain border for any apoplasmic transport. It constitutes a key point of control for nutrient transport, where the opposing flow of mineral nutrients and photoassimilates has to be accommodated in each single cell, bringing to mind the principle of a revolving door. The review lists a number of experiments needed to elucidate the mode of phloem loading in gymnosperms. PMID:21107620

Anatomical and neurohistological observations on the heart of the rose ringed parakeet, Psittacula krameri.

PubMed

Qayyum, M A; Shaad, F U

1976-01-01

Anatomy, histology and innervation of the heart of the rose ringed parakeet, Psittacula krameri have been studied in the present investigation. The sinuatrial node is found to be well-developed. It is located towards the right side of the cephalic end of the interatrial septum and composed of a few nucleated cells and a large fibrous mass. The atrioventricular node is poorly defined, present at the caudal end of the interatrial septum. The node is somewhat triangular in shape and is composed of elongated and multinucleated specialized fibres. The node is not covered by any connective tissue sheath. The poor development of the atrio ventricular node and the absence of any sheath around it may be correlated with the fast rate of the heart beat. The atrioventricular bundle is observed at the cephalic end of the interventricular septum. A branch from the right limb of the atrioventricular bundle is noted to pass directly into the right atrioventricular valve. The heart is richly innervated. Ganglion cells along with nerve fibres have been observed at the sulcus terminalis and the atrioventricular junction. A direct nervous connection could be observed between the sinuatrial and atrioventricular nodes. It is argued that the impulse which originates in the sinuatrial node would reach the atrioventricular node through the unspecialized muscle fibres and nerve fibres of the interatrial septum. Nerve cells could not be traced in the substance of the sinuatrial node, atrioventricular node and atrioventricular bundle.

Change in desorption mechanism from pore blocking to cavitation with temperature for nitrogen in ordered silica with cagelike pores.

PubMed

Morishige, Kunimitsu; Tateishi, Masayoshi; Hirose, Fumi; Aramaki, Kenji

2006-10-24

To verify pore blocking controlled desorption in ink-bottle pores, we measured the temperature dependence of the adsorption-desorption isotherms of nitrogen on four kinds of KIT-5 samples with expanded cavities hydrothermally treated for different periods of time at 393 K. In the samples, almost spherical cavities are arranged in a face-centered cubic array and the cavities are connected through small channels. The pore size of the channels increased with an increase in the hydrothermal treatment time. At lower temperatures a steep desorption branch changed to a gradual one as the hydrothermal treatment was prolonged. For the sample hydrothermally treated only for 1 day, the rectangular hysteresis loop shrank gradually with increasing temperature while keeping its shape. The temperature dependence of the evaporation pressure observed was identical with that expected for cavitation-controlled desorption. On the other hand, for the samples hydrothermally treated for long times, the gradual desorption branch became a sharp one with increasing temperature. This strongly suggests that the desorption mechanism is altered from pore blocking to cavitation with temperature. Application of percolation theory to the pore blocking controlled desorption observed here is discussed.

Theoretical study of the self-assembly of Janus Bottlebrush Polymers from A-Branch-B Diblock Macromonomers

NASA Astrophysics Data System (ADS)

Gadelrab, Karim; Alexander-Katz, Alfredo; LaboratoryTheoretical Soft Materials Team

The self-assembly of block copolymers BCP has provided an impressive control over the nanoscale structure of soft matter. While the main focus of the research in the field has been directed towards simple linear diblocks, the development of advanced polymer architecture provided improved performance and access to new structures. In particular, bottlebrush BCPs (BBCPs) have interesting characteristics due to their dense functionality, high molecular weight, low levels of entanglement, and tendency to efficiently undergo rapid bulk phase separation. In this work, we are interested in theoretically studying the self-assembly of Janus-type ``A-branch-B'' BBCPs where A and B blocks can phase separate with the bottlebrush polymer backbone serving as the interface between the two blocks. Hence, the polymer backbone adds an extra constraint on the equilibrium spacing between neighboring linear diblock chains. In this regard, the segment length of the backbone separating the AB junctions has a direct effect of the observed domain spacing and effective segregation strength of the AB blocks. We employ self-consistent field theoretic SCFT simulations to capture the effect of volume fraction of different constituents and construct a phase diagram of the accessible morphologies of these BBCPs.

A NEW PRINCIPLE FOR ELECTROMAGNETIC CATHETER FLOW METERS*

PubMed Central

Kolin, Alexander

1969-01-01

An electromagnetic catheter flow meter is described in which the magnetic field is generated by two parallel bundles of wire carrying equal currents in opposite directions. The electrodes are fixed centrally to the insulated wire bundles that generate the magnetic field. The flow sensor is flexible, resembling a split catheter. The flow transducer is designed to constrict as it is introduced through a branch artery and to expand in the main artery over the span of its diameter. The principle is suitable for branch flow measurement as well as for measurement of flow in a major artery or vein by the same transducer. A special method of guiding the electrode wires results in a zero base line at zero flow for the entire range of diameters accommodating the field generating coil. The electrodes could be used in this configuration with a magnetic field generated by coils external to the patient for blood flow measurements with a catheter of reduced gauge. The transducer can be made smaller in circumference than those employed in other electromagnetic flow measuring catheter devices. This feature is of special value for envisaged clinical uses (percutaneous introduction) to minimize surgical intervention. The velocity sensitivity of the flow transducer is a logarithmic function of the tube diameter. The flow throughout the entire tube cross section contributes to the flow signal. It is sufficient to calibrate the transducer by one measurement in a dielectric conduit of less than maximum diameter. The sensitivity at other diameters follows from a logarithmic plot. The diameter of the blood vessel is outlined by the transducer in radiograms, thus obviating the need for radiopaque materials. The principle was demonstrated by measurements in vitro. Experiments in vivo, derivation of equations, and construction details will be published elsewhere. Images PMID:5257127

Growth of modern branched columnar stromatolites in Lake Joyce, Antarctica.

PubMed

Mackey, T J; Sumner, D Y; Hawes, I; Jungblut, A D; Andersen, D T

2015-07-01

Modern decimeter-scale columnar stromatolites from Lake Joyce, Antarctica, show a change in branching pattern during a period of lake level rise. Branching patterns correspond to a change in cyanobacterial community composition as preserved in authigenic calcite crystals. The transition in stromatolite morphology is preserved by mineralized layers that contain microfossils and cylindrical molds of cyanobacterial filaments. The molds are composed of two populations with different diameters. Large diameter molds (>2.8 μm) are abundant in calcite forming the oldest stromatolite layers, but are absent from younger layers. In contrast, <2.3 μm diameter molds are common in all stromatolites layers. Loss of large diameter molds corresponds to the transition from smooth-sided stromatolitic columns to branched and irregular columns. Mold diameters are similar to trichome diameters of the four most abundant living cyanobacteria morphotypes in Lake Joyce: Phormidium autumnale morphotypes have trichome diameters >3.5 μm, whereas Leptolyngbya antarctica, L. fragilis, and Pseudanabaena frigida morphotypes have diameters <2.3 μm. P. autumnale morphotypes were only common in mats at <12 m depth. Mats containing abundant P. autumnale morphotypes were smooth, whereas mats with few P. autumnale morphotypes contained small peaks and protruding bundles of filaments, suggesting that the absence of P. autumnale morphotypes allowed small-scale topography to develop on mats. Comparisons of living filaments and mold diameters suggest that P. autumnale morphotypes were present early in stromatolite growth, but disappeared from the community through time. We hypothesize that the mat-smoothing behavior of P. autumnale morphotypes inhibited nucleation of stromatolite branches. When P. autumnale morphotypes were excluded from the community, potentially reflecting a rise in lake level, short-wavelength roughness provided nuclei for stromatolite branches. This growth history provides a conceptual model for initiation of branched stromatolite growth resulting from a change in microbial community composition. © 2015 John Wiley & Sons Ltd.

Co-Registration of Terrestrial and Uav-Based Images - Experimental Results

NASA Astrophysics Data System (ADS)

Gerke, M.; Nex, F.; Jende, P.

2016-03-01

For many applications within urban environments the combined use of images taken from the ground and from unmanned aerial platforms seems interesting: while from the airborne perspective the upper parts of objects including roofs can be observed, the ground images can complement the data from lateral views to retrieve a complete visualisation or 3D reconstruction of interesting areas. The automatic co-registration of air- and ground-based images is still a challenge and cannot be considered solved. The main obstacle is originating from the fact that objects are photographed from quite different angles, and hence state-of-the-art tie point measurement approaches cannot cope with the induced perspective transformation. One first important step towards a solution is to use airborne images taken under slant directions. Those oblique views not only help to connect vertical images and horizontal views but also provide image information from 3D-structures not visible from the other two directions. According to our experience, however, still a good planning and many images taken under different viewing angles are needed to support an automatic matching across all images and complete bundle block adjustment. Nevertheless, the entire process is still quite sensible - the removal of a single image might lead to a completely different or wrong solution, or separation of image blocks. In this paper we analyse the impact different parameters and strategies have on the solution. Those are a) the used tie point matcher, b) the used software for bundle adjustment. Using the data provided in the context of the ISPRS benchmark on multi-platform photogrammetry, we systematically address the mentioned influences. Concerning the tie-point matching we test the standard SIFT point extractor and descriptor, but also the SURF and ASIFT-approaches, the ORB technique, as well as (A)KAZE, which are based on a nonlinear scale space. In terms of pre-processing we analyse the Wallis-filter. Results show that in more challenging situations, in this case for data captured from different platforms at different days most approaches do not perform well. Wallis-filtering emerged to be most helpful especially for the SIFT approach. The commercial software pix4dmapper succeeds in overall bundle adjustment only for some configurations, and especially not for the entire image block provided.

Framework for cascade size calculations on random networks

NASA Astrophysics Data System (ADS)

Burkholz, Rebekka; Schweitzer, Frank

2018-04-01

We present a framework to calculate the cascade size evolution for a large class of cascade models on random network ensembles in the limit of infinite network size. Our method is exact and applies to network ensembles with almost arbitrary degree distribution, degree-degree correlations, and, in case of threshold models, for arbitrary threshold distribution. With our approach, we shift the perspective from the known branching process approximations to the iterative update of suitable probability distributions. Such distributions are key to capture cascade dynamics that involve possibly continuous quantities and that depend on the cascade history, e.g., if load is accumulated over time. As a proof of concept, we provide two examples: (a) Constant load models that cover many of the analytically tractable casacade models, and, as a highlight, (b) a fiber bundle model that was not tractable by branching process approximations before. Our derivations cover the whole cascade dynamics, not only their steady state. This allows us to include interventions in time or further model complexity in the analysis.

Accuracy of ultrasound-guided nerve blocks of the cervical zygapophysial joints.

PubMed

Siegenthaler, Andreas; Mlekusch, Sabine; Trelle, Sven; Schliessbach, Juerg; Curatolo, Michele; Eichenberger, Urs

2012-08-01

Cervical zygapophysial joint nerve blocks typically are performed with fluoroscopic needle guidance. Descriptions of ultrasound-guided block of these nerves are available, but only one small study compared ultrasound with fluoroscopy, and only for the third occipital nerve. To evaluate the potential usefulness of ultrasound-guidance in clinical practice, studies that determine the accuracy of this technique using a validated control are essential. The aim of this study was to determine the accuracy of ultrasound-guided nerve blocks of the cervical zygapophysial joints using fluoroscopy as control. Sixty volunteers were studied. Ultrasound-imaging was used to place the needle to the bony target of cervical zygapophysial joint nerve blocks. The levels of needle placement were determined randomly (three levels per volunteer). After ultrasound-guided needle placement and application of 0.2 ml contrast dye, fluoroscopic imaging was performed for later evaluation by a blinded pain physician and considered as gold standard. Raw agreement, chance-corrected agreement κ, and chance-independent agreement Φ between the ultrasound-guided placement and the assessment using fluoroscopy were calculated to quantify accuracy. One hundred eighty needles were placed in 60 volunteers. Raw agreement was 87% (95% CI 81-91%), κ was 0.74 (0.64-0.83), and Φ 0.99 (0.99-0.99). Accuracy varied significantly between the different cervical nerves: it was low for the C7 medial branch, whereas all other levels showed very good accuracy. Ultrasound-imaging is an accurate technique for performing cervical zygapophysial joint nerve blocks in volunteers, except for the medial branch blocks of C7.

Reversible second degree atrioventricular block after a severe sickle cell crisis.

PubMed

Jaeggi, E; Bolens, M; Friedli, B

1998-01-01

Despite the high prevalence of sickle cell disease and trait in the black population and its serious potential for microinfarction, there are only a few reports on acute myocardial damage during vasoocclusive crisis. We report a unique case of transient second degree atrioventricular (A-V) block of Mobitz I and II type during a severe sickle cell crisis. Localized high ventricular septum hypoperfusion demonstrated by a 99mTc-MIBI radionuclide study and reversible echocardiographic wall motion abnormalities in the same area were strong indicators for a local ischemic event in the A-V node and His bundle area, explaining the observed transient conduction abnormalities. The present report draws attention to a potentially lethal complication of sickle cell crisis.

C-terminal fragment of amebin promotes actin filament bundling, inhibits acto-myosin ATPase activity and is essential for amoeba migration.

PubMed

Jóźwiak, Jolanta; Rzhepetskyy, Yuriy; Sobczak, Magdalena; Kocik, Elżbieta; Skórzewski, Radosław; Kłopocka, Wanda; Rędowicz, Maria Jolanta

2011-02-01

Amebin [formerly termed as ApABP-FI; Sobczak et al. (2007) Biochem. Cell Biol. 85] is encoded in Amoeba proteus by two transcripts, 2672-nt and 1125-nt. A product of the shorter transcript (termed as C-amebin), comprising C-terminal 375 amino-acid-residue fragment of amebin, has been expressed and purified as the recombinant GST-fusion protein. GST-C-amebin bound both to monomeric and filamentous actin. The binding was Ca(2+)-independent and promoted filament bundling, as revealed with the transmission electron microscopy. GST-C-amebin significantly decreased MgATPase activity of rabbit skeletal muscle acto-S1. Removal with endoproteinase ArgC of a positively charged C-terminal region of GST-amebin containing KLASMWEQ sequence abolished actin-binding and bundling as well as the ATPase-inhibitory effect of C-amebin, indicating that this protein region was involved in the interaction with actin. Microinjection of amoebae with antibody against C-terminus of amebin significantly affected amoebae morphology, disturbed cell polarization and transport of cytoplasmic granules as well as blocked migration. These data indicate that amebin may be one of key regulators of the actin-cytoskeleton dynamics and actin-dependent motility in A. proteus. Copyright © 2010 Elsevier Inc. All rights reserved.

High-Resolution Topography of Mercury from Messenger Orbital Stereo Imaging - the Southern Hemisphere Quadrangles

NASA Astrophysics Data System (ADS)

Preusker, F.; Oberst, J.; Stark, A.; Burmeister, S.

2018-04-01

We produce high-resolution (222 m/grid element) Digital Terrain Models (DTMs) for Mercury using stereo images from the MESSENGER orbital mission. We have developed a scheme to process large numbers, typically more than 6000, images by photogrammetric techniques, which include, multiple image matching, pyramid strategy, and bundle block adjustments. In this paper, we present models for map quadrangles of the southern hemisphere H11, H12, H13, and H14.

Effect of Pulsed Radiofrequency Treatment on the Thoracic Medial Branch for Managing Chronic Thoracic Facet Joint Pain Refractory to Medial Branch Block with Local Anesthetics.

PubMed

Chang, Min Cheol

2018-03-01

To evaluate the effect of pulsed radiofrequency (PRF) stimulation of the thoracic medial branch of the dorsal ramus in patients with chronic thoracic facet joint (TFJ) pain who were refractory to medial branch block (MBB). This was a prospective, observational study. The author retrospectively reviewed data from 72 patients who had received therapeutic MBB with 0.5 mL of 2% lidocaine mixed with 0.5 mL of 0.25% bupivacaine to treat TFJ-origin upper or midback pain. Of these patients, 20 were included to evaluate the effects of PRF on the thoracic medical branch to manage TFJ pain refractory to therapeutic MBB. PRF stimulation was administered at 5 Hz and a 5-millisecond pulsed width for 360 seconds at 45 V. The pain-reducing effect of the PRF procedure was evaluated via the numeric rating scale (NRS) at 1, 2, and 3 months after treatment. Successful pain relief was defined as ≥50% reduction in the NRS score compared with the score before treatment. The NRS scores changed significantly over time (pretreatment, 6.0 ± 1.0; 1 month, 3.3 ± 2.2; 2 months, 3.9 ± 2.1; and 3 months, 4.0 ± 2.2). At 1, 2, and 3 months after the PRF procedure, the NRS scores were significantly reduced compared with the scores before the treatment. Eleven (55%) of 20 patients reported successful pain relief at 3 months after PRF. The author suggests that PRF on the thoracic medial branch is an effective and safe interventional technique for the control of chronic TFJ pain. Copyright © 2017 Elsevier Inc. All rights reserved.

extendFromReads

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Kelly P.

2013-10-03

This package assists in genome assembly. extendFromReads takes as input a set of Illumina (eg, MiSeq) DNA sequencing reads, a query seed sequence and a direction to extend the seed. The algorithm collects all seed-- ]matching reads (flipping reverse-- ]orientation hits), trims off the seed and additional sequence in the other direction, sorts the remaining sequences alphabetically, and prints them aligned without gaps from the point of seed trimming. This produces a visual display distinguishing the flanks of multi- ]copy seeds. A companion script hitMates.pl collects the mates of seed-- ]hi]ng reads, whose alignment reveals longer extensions from the seed.more » The collect/trim/sort strategy was made iterative and scaled up in the script denovo.pl, for de novo contig assembly. An index is pre-- ]built using indexReads.pl that for each unique 21-- ]mer found in all the reads, records its gfate h of extension (whether extendable, blocked by low coverage, or blocked by branching after a duplicated sequence) and other characteristics. Importantly, denovo.pl records all branchings that follow a branching contig endpoint, providing contig- ]extension information« less

Treatment of chronic neurogenic cough with in-office superior laryngeal nerve block.

PubMed

Simpson, C Blake; Tibbetts, Kathleen M; Loochtan, Michael J; Dominguez, Laura M

2018-04-18

Neurogenic cough is believed to result from a sensory neuropathy involving the internal branch of the superior laryngeal nerve (SLN). We present our outcomes for the treatment of neurogenic cough with localized blockade of the internal branch of the SLN. A retrospective chart review of patients who underwent in-office percutaneous SLN block for treatment of neurogenic cough between 2015 and 2017 was conducted. Patient demographics, indications for injection, and response to treatment were recorded and analyzed. Cough severity index (CSI) scores before and after treatment were compared. Twenty-three patients underwent percutaneous blockade of the internal branch of the SLN in the clinic setting, and five patients were excluded for incomplete records. The indication was neurogenic cough as a diagnosis of exclusion. The injectable substance used was a 1:1 mixture of a long-acting particulate corticosteroid and a local anesthetic. Unilateral injections were performed in 13 patients, and five patients underwent bilateral injections. Of the unilateral injections, 10 were left-sided. Patients underwent an average of 2.4 SLN block procedures (range 1-7). Mean follow-up time postinjection was 85.4 days (7-450 days). Cough severity index scores decreased significantly from an average of 26.8 pretreatment to 14.6 posttreatment (P < 0.0001). The SLN block is an effective treatment for neurogenic cough, with average CSI scores significantly improved following injection. Further study is necessary to determine the characteristics of patients' responses to treatment, long-term outcomes, and efficacy of the procedure when compared to placebo and other accepted treatments for neurogenic cough. 4. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

Left ventricular approach for recording His bundle potential in man.

PubMed

Lee, Y S; Lien, W P

1975-06-01

The electrical potentials of the His bundle (HB) were recorded from the left ventricular endocardial surface in 28 patients ranging from 16 to 63 years of age. In 14 of the patients the left bundle branch (LB) potentials were also obtained. Placement of a bipolar electrode catheter tip toward the interventricular septum, right at and also 1 to 2 cm below the aortic valve, resulted in stable recordings of both potentials in successive cardiac cycles even at performing atrial or HB pacing from the right heart. The following intervals were measured in milliseconds (msec): P-A, A-H, H, H-V, LB, and LB-V. The average values in 12 patients (average age 26 plus or minus 7 years and average heart rate 90 plus or minus 16 beats per minute) with normal A-V conduction were as follows: P-A 28 plus or minus 7, A-H 76 plus or minus 16, H 19 plus or minus 3 and H-V 45 plus or minus 6 msec. The average values for LB and LB-V in 10 of these 12 patients were 15 plus or minus 3 and 25 plus or minus 3 msec respectively. Validation of the His bundle electrogram (HBE) from the left ventricular endocardial surface was based on simultaneous recordings of the intracardiac electrograms from both left and right sides of the heart in 18 patients. The individual average values for the intervals obtained from both sides of the heart in these patients were statistically not different, except that the H potential was slightly longer in duration fr m the left heart (P equals 0.05). Among these, 16 showed simultaneous onset of the H potentials, and the LB-V and RB-V conduction times from comparable points were almost the same. Indications for the left sided electro-physiologic studies include the following situations: (a) inability to record H from the right of the heart; (b) giant right atrium; and (c) possibly during atrial fibrillation.

Whole-Mount Adult Ear Skin Imaging Reveals Defective Neuro-Vascular Branching Morphogenesis in Obese and Type 2 Diabetic Mouse Models.

PubMed

Yamazaki, Tomoko; Li, Wenling; Yang, Ling; Li, Ping; Cao, Haiming; Motegi, Sei-Ichiro; Udey, Mark C; Bernhard, Elise; Nakamura, Takahisa; Mukouyama, Yoh-Suke

2018-01-11

Obesity and type 2 diabetes are frequently associated with peripheral neuropathy. Though there are multiple methods for diagnosis and analysis of morphological changes of peripheral nerves and blood vessels, three-dimensional high-resolution imaging is necessary to appreciate the pathogenesis with an anatomically recognizable branching morphogenesis and patterning. Here we established a novel technique for whole-mount imaging of adult mouse ear skin to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels. Whole-mount immunostaining of adult mouse ear skin showed that peripheral sensory and sympathetic nerves align with large-diameter blood vessels. Diet-induced obesity (DIO) mice exhibit defective vascular smooth muscle cells (VSMCs) coverage, while there is no significant change in the amount of peripheral nerves. The leptin receptor-deficient db/db mice, a severe obese and type 2 diabetic mouse model, exhibit defective VSMC coverage and a large increase in the amount of smaller-diameter nerve bundles with myelin sheath and unmyelinated nerve fibers. Interestingly, an increase in the amount of myeloid immune cells was observed in the DIO but not db/db mouse skin. These data suggest that our whole-mount imaging method enables us to investigate the neuro-vascular and neuro-immune phenotypes in the animal models of obesity and diabetes.

Highways of the emotional intellect: white matter microstructural correlates of an ability-based measure of emotional intelligence.

PubMed

Pisner, Derek A; Smith, Ryan; Alkozei, Anna; Klimova, Aleksandra; Killgore, William D S

2017-06-01

Individuals differ in their ability to understand emotional information and apply that understanding to make decisions and solve problems effectively - a construct known as Emotional Intelligence (EI). While considerable evidence supports the importance of EI in social and occupational functioning, the neural underpinnings of this capacity are relatively unexplored. We used Tract-Based Spatial Statistics (TBSS) to determine the white matter correlates of EI as measured by the ability-based Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Participants included 32 healthy adults (16 men; 16 women), aged 18-45 years. White matter integrity in key tracts was positively correlated with the Strategic Area branches of the MSCEIT (Understanding Emotions and Managing Emotions), but not the Experiential branches (Perceiving and Facilitating Emotions). Specifically, the Understanding Emotions branch was associated with greater fractional anisotropy (FA) within somatosensory and sensory-motor fiber bundles, particularly those of the left superior longitudinal fasciculus and corticospinal tract. Managing Emotions was associated with greater FA within frontal-affective association tracts including the anterior forceps and right uncinate fasciculus, along with frontal-parietal cingulum and interhemispheric corpus callosum tracts. These findings suggest that specific components of EI are directly related to the structural microarchitecture of major axonal pathways.

Rational growth of branched nanowire heterostructures with synthetically encoded properties and function

PubMed Central

Jiang, Xiaocheng; Tian, Bozhi; Xiang, Jie; Qian, Fang; Zheng, Gengfeng; Wang, Hongtao; Mai, Liqiang; Lieber, Charles M.

2011-01-01

Branched nanostructures represent unique, 3D building blocks for the “bottom-up” paradigm of nanoscale science and technology. Here, we report a rational, multistep approach toward the general synthesis of 3D branched nanowire (NW) heterostructures. Single-crystalline semiconductor, including groups IV, III–V, and II–VI, and metal branches have been selectively grown on core or core/shell NW backbones, with the composition, morphology, and doping of core (core/shell) NWs and branch NWs well controlled during synthesis. Measurements made on the different composition branched NW structures demonstrate encoding of functional p-type/n-type diodes and light-emitting diodes (LEDs) as well as field effect transistors with device function localized at the branch/backbone NW junctions. In addition, multibranch/backbone NW structures were synthesized and used to demonstrate capability to create addressable nanoscale LED arrays, logic circuits, and biological sensors. Our work demonstrates a previously undescribed level of structural and functional complexity in NW materials, and more generally, highlights the potential of bottom-up synthesis to yield increasingly complex functional systems in the future. PMID:21730174

Angiogenesis-Based Cancer Therapeutic | NCI Technology Transfer Center | TTC

Cancer.gov

The National Cancer Institute's Urologic Oncology Branch seeks interested parties to co-develop antagonists to VEGF-A and hepatocyte growth factor (HGF) that block signal transduction and associated cellular responses.

Recovery from distal ulnar motor conduction block injury: serial EMG studies.

PubMed

Montoya, Liliana; Felice, Kevin J

2002-07-01

Acute conduction block injuries often result from nerve compression or trauma. The temporal pattern of clinical, electrophysiologic, and histopathologic changes following these injuries has been extensively studied in experimental animal models but not in humans. Our recent evaluation of a young man with an injury to the deep motor branch of the ulnar nerve following nerve compression from weightlifting exercises provided the opportunity to follow the course and recovery of a severe conduction block injury with sequential nerve conduction studies. The conduction block slowly and completely resolved, as did the clinical deficit, over a 14-week period. The reduction in conduction block occurred at a linear rate of -6.1% per week. Copyright 2002 Wiley Periodicals, Inc.

The iMars web-GIS - spatio-temporal data queries and single image web map services

NASA Astrophysics Data System (ADS)

Walter, S. H. G.; Steikert, R.; Schreiner, B.; Sidiropoulos, P.; Tao, Y.; Muller, J.-P.; Putry, A. R. D.; van Gasselt, S.

2017-09-01

We introduce a new approach for a system dedicated to planetary surface change detection by simultaneous visualisation of single-image time series in a multi-temporal context. In the context of the EU FP-7 iMars project we process and ingest vast amounts of automatically co-registered (ACRO) images. The base of the co-registration are the high precision HRSC multi-orbit quadrangle image mosaics, which are based on bundle-block-adjusted multi-orbit HRSC DTMs.

Multi-model stereo restitution

USGS Publications Warehouse

Dueholm, K.S.

1990-01-01

Methods are described that permit simultaneous orientation of many small-frame photogrammetric models in an analytical plotter. The multi-model software program enables the operator to move freely between the oriented models during interpretation and mapping. Models change automatically when the measuring mark is moved from one frame to another, moving to the same ground coordinates in the neighboring model. Thus, data collection and plotting can be performed continuously across model boundaries. The orientation of the models is accomplished by a bundle block adjustment. -from Author

Understanding the Effect of the Dianhydride Structure on the Properties of Semiaromatic Polyimides Containing a Biobased Fatty Diamine

PubMed Central

2017-01-01

In this work we report the effect of the hard block dianhydride structure on the overall properties of partially biobased semiaromatic polyimides. For the study, four polyimides were synthesized using aliphatic fatty dimer diamine (DD1) as the soft block and four different commercially available aromatic dianhydrides as the hard block: 4,4′-(4,4′-isopropylidenediphenoxy) bis(phthalic anhydride) (BPADA), 4,4′-oxidiphthalic anhydride (ODPA), 4,4′-(Hexafluoroisopropylidene) diphthalic anhydride (6FDA), and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA). The polymers synthesized were fully organo-soluble thermoplastic branched polyimides with glass transition temperatures close to room temperature. The detailed analysis took into account several aspects of the dianhydrides structure (planarity, rigidity, bridging group between the phtalimides, and electronic properties) and related them to the results obtained by differential scanning calorimetry, rheology, fluorescence and broadband dielectric spectroscopy. Moreover, the effects of physical parameters (crystallization and electronic interactions) on the relaxation behavior are discussed. Despite the presence of the bulky branched soft block given by the dimer diamine, all polyimides showed intermolecular charge transfer complexes, whose extent depends on the electronic properties of the dianhydride hard block. Furthermore, the results showed that polyimides containing flexible and bulky hard blocks turned out fully amorphous while the more rigid dianhydride (BPDA) led to a nanophase separated morphology with low degree of crystallinity resulting in constrained segmental relaxation with high effect on its mechanical response with the annealing time. This work represents the first detailed report on the development and characterization of polyimides based on a biobased fatty dimer diamine. The results highlight the potential of polymer property design by controlled engineering of the aromatic dianhydride blocks. PMID:29333351

Whiplash and Whiplash Associated Disorder (WAS)

MedlinePlus

... Patient Education Committee The spine is a long chain of bones, discs, muscles and ligaments that extends ... is to perform an injection called "medial branch block (MBB)," which is discussed below. Disc injury can ...

Vasovagal Rates in Flouroscopically Guided Interventional Procedures: A Study of Over 8,000 Injections

PubMed Central

Kennedy, David J.; Schneider, Byron; Casey, Ellen; Rittenberg, Joshua; Conrad, Bryan; Smuck, Matthew; Plastaras, Christopher T.

2014-01-01

Objective To determine the rate of vasovagal (vv) complications in fluoroscopically guided interventional procedures. Design Retrospective case series analysis of prospectively collected data from March 8, 2004 to January 30, 2009. Setting A single academic medical center. Subjects Four thousand one hundred eighty-three subjects undergoing 8,010 consecutive injections. Outcome Measures Pearson's chi-square test was used to determine the relationship between categorical variables. Results A total of 8,010 injections, including epidural steroid injections, radiofrequency nerve ablations, medial branch blocks, hip injections, knee injections, and glenohumeral injections were performed. Overall vv reaction rate was 2.6%, with 0.8% of procedures resulting in early terminated due to vv reaction. Peripheral joint injections had a vv rate of 0.2%, all occurring in hip injections. Transforaminal epidural steroid injections had a vv rate of 3.5%. Diagnostic blocks of the medial branches had the highest rate of vv (5.1%). Other predictors of vv reactions were identified including preprocedure pain score visual analog scale <5 (P = 0.004), male gender (P < 0.001), and age less than 65 years old (P < 0.001). Conclusions vv reactions have an overall low occurrence rate (2.6%) in interventional procedures ranging from 0% in peripheral knee and shoulder injections to 5.1% in medial branch blocks. Conservative treatment of vv reaction and willingness to terminate procedures resulted in no serious adverse events related to vv reaction in 8,010 procedures. PMID:24118835

Middle Triassic back-arc basalts from the blocks in the Mersin Mélange, southern Turkey: Implications for the geodynamic evolution of the Northern Neotethys

NASA Astrophysics Data System (ADS)

Sayit, Kaan; Bedi, Yavuz; Tekin, U. Kagan; Göncüoglu, M. Cemal; Okuyucu, Cengiz

2017-01-01

The Mersin Mélange is a tectonostratigraphic unit within the allochthonous Mersin Ophiolitic Complex in the Taurides, southern Turkey. This chaotic structure consists of blocks and tectonic slices of diverse origins and ages set in a clastic matrix of Upper Cretaceous age. In this study, we examine two blocks at two different sections characterized by basaltic lava flows alternating with radiolarian-bearing pelagic sediments. The radiolarian assemblage extracted from the mudstone-chert alternation overlying the lavas yields an upper Anisian age (Middle Triassic). The immobile element geochemistry suggests that the lava flows are predominantly characterized by sub-alkaline basalts. All lavas display pronounced negative Nb anomalies largely coupled with normal mid-ocean basalt (N-MORB)-like high field strength element (HFSE) patterns. On the basis of geochemical modelling, the basalts appear to have dominantly derived from spinel-peridotite and pre-depleted spinel-peridotite sources, while some enriched compositions can be explained by contribution of garnet-facies melts from enriched domains. The overall geochemical characteristics suggest generation of these Middle Triassic lavas at an intra-oceanic back-arc basin within the northern branch of Neotethys. This finding is of significant importance, since these rocks may represent the presence of the oldest subduction zone found thus far from the Neotethyan branches. This, in turn, suggests that the rupturing of the Gondwanan lithosphere responsible for the opening of the northern branch of Neotethys should have occurred during the Lower Triassic or earlier.

Shape analysis of the cingulum, uncinate and arcuate fasciculi in patients with bipolar disorder

PubMed Central

Sun, Zhong Yi; Houenou, Josselin; Duclap, Delphine; Sarrazin, Samuel; Linke, Julia; Daban, Claire; Hamdani, Nora; d’Albis, Marc-Antoine; Le Corvoisier, Philippe; Guevara, Pamela; Delavest, Marine; Bellivier, Frank; Almeida, Jorge; Versace, Amelia; Poupon, Cyril; Leboyer, Marion; Phillips, Mary; Wessa, Michèle; Mangin, Jean-François

2017-01-01

Background Abnormal maturation of brain connectivity is supposed to underlie the dysfunctional emotion regulation in patients with bipolar disorder (BD). To test this hypothesis, white matter integrity is usually investigated using measures of water diffusivity provided by MRI. Here we consider a more intuitive aspect of the morphometry of the white matter tracts: the shape of the fibre bundles, which is associated with neurodevelopment. We analyzed the shape of 3 tracts involved in BD: the cingulum (CG), uncinate fasciculus (UF) and arcuate fasciculus (AF). Methods We analyzed diffusion MRI data in patients with BD and healthy controls. The fibre bundles were reconstructed using Q-ball–based tractography and automated segmentation. Using Isomap, a manifold learning method, the differences in the shape of the reconstructed bundles were visualized and quantified. Results We included 112 patients and 82 controls in our analysis. We found the left AF of patients to be further extended toward the temporal pole, forming a tighter hook than in controls. We found no significant difference in terms of shape for the left UF, the left CG or the 3 right fasciculi. However, in patients compared with controls, the ventrolateral branch of the left UF in the orbitofrontal region had a tendency to be larger, and the left CG of patients had a tendency to be smaller in the frontal lobe and larger in the parietal lobe. Limitations This was a cross-sectional study. Conclusion Our results suggest neurodevelopmental abnormalities in the left AF in patients with BD. The statistical tendencies observed for the left UF and left CG deserve further study. PMID:28234596

Shape analysis of the cingulum, uncinate and arcuate fasciculi in patients with bipolar disorder.

PubMed

Sun, Zhong Yi; Houenou, Josselin; Duclap, Delphine; Sarrazin, Samuel; Linke, Julia; Daban, Claire; Hamdani, Nora; d'Albis, Marc-Antoine; Le Corvoisier, Philippe; Guevara, Pamela; Delavest, Marine; Bellivier, Frank; Bellivier, Frank; Almeida, Jorge; Versace, Amelia; Poupon, Cyril; Leboyer, Marion; Phillips, Mary; Wessa, Michèle; Mangin, Jean-François

2017-01-01

Abnormal maturation of brain connectivity is supposed to underlie the dysfunctional emotion regulation in patients with bipolar disorder (BD). To test this hypothesis, white matter integrity is usually investigated using measures of water diffusivity provided by MRI. Here we consider a more intuitive aspect of the morphometry of the white matter tracts: the shape of the fibre bundles, which is associated with neurodevelopment. We analyzed the shape of 3 tracts involved in BD: the cingulum (CG), uncinate fasciculus (UF) and arcuate fasciculus (AF). We analyzed diffusion MRI data in patients with BD and healthy controls. The fibre bundles were reconstructed using Q-ball-based tractography and automated segmentation. Using Isomap, a manifold learning method, the differences in the shape of the reconstructed bundles were visualized and quantified. We included 112 patients and 82 controls in our analysis. We found the left AF of patients to be further extended toward the temporal pole, forming a tighter hook than in controls. We found no significant difference in terms of shape for the left UF, the left CG or the 3 right fasciculi. However, in patients compared with controls, the ventrolateral branch of the left UF in the orbitofrontal region had a tendency to be larger, and the left CG of patients had a tendency to be smaller in the frontal lobe and larger in the parietal lobe. This was a cross-sectional study. Our results suggest neurodevelopmental abnormalities in the left AF in patients with BD. The statistical tendencies observed for the left UF and left CG deserve further study.

Stranded cost recovery presents stumbling block to open access

DOE Office of Scientific and Technical Information (OSTI.GOV)

Del Roccili, J.A.

Much of the impetus for the movement to competitive power markets is a result of the tremendous variance in energy prices across the country. Large commercial and industrial customers are becoming increasingly aware of these discrepancies and are marshaling the market and political forces required to guarantee the eventual development of a national open-access transmission policy. Such a policy will facilitate competition and equalize prices on a regional, and to some extent, national level. The stumbling block, however, is the recovery of stranded investment. Under traditional regulation, historical costs could be collected through approved rates for a bundled service. Withmore » the protection of a monopoly franchise, average electricity prices provide the possibility of cost recovery for assets that might not be recoverable in a competitive market.« less

Lineage-associated tracts defining the anatomy of the Drosophila first instar larval brain

PubMed Central

Hartenstein, Volker; Younossi-Hartenstein, Amelia; Lovick, Jennifer; Kong, Angel; Omoto, Jaison; Ngo, Kathy; Viktorin, Gudrun

2015-01-01

Fixed lineages derived from unique, genetically specified neuroblasts form the anatomical building blocks of the Drosophila brain. Neurons belonging to the same lineage project their axons in a common tract, which is labeled by neuronal markers. In this paper, we present a detailed atlas of the lineage-associated tracts forming the brain of the early Drosophila larva, based on the use of global markers (anti-Neuroglian, anti-Neurotactin, Inscuteable-Gal4>UAS-chRFP-Tub) and lineage-specific reporters. We describe 68 discrete fiber bundles that contain axons of one lineage or pairs/small sets of adjacent lineages. Bundles enter the neuropil at invariant locations, the lineage tract entry portals. Within the neuropil, these fiber bundles form larger fascicles that can be classified, by their main orientation, into longitudinal, transverse, and vertical (ascending/descending) fascicles. We present 3D digital models of lineage tract entry portals and neuropil fascicles, set into relationship to commonly used, easily recognizable reference structures such as the mushroom body, the antennal lobe, the optic lobe, and the Fasciclin II-positive fiber bundles that connect the brain and ventral nerve cord. Correspondences and differences between early larval tract anatomy and the previously described late larval and adult lineage patterns are highlighted. Our L1 neuro-anatomical atlas of lineages constitutes an essential step towards following morphologically defined lineages to the neuroblasts of the early embryo, which will ultimately make it possible to link the structure and connectivity of a lineage to the expression of genes in the particular neuroblast that gives rise to that lineage. Furthermore, the L1 atlas will be important for a host of ongoing work that attempts to reconstruct neuronal connectivity at the level of resolution of single neurons and their synapses. PMID:26141956

Lineage-associated tracts defining the anatomy of the Drosophila first instar larval brain.

PubMed

Hartenstein, Volker; Younossi-Hartenstein, Amelia; Lovick, Jennifer K; Kong, Angel; Omoto, Jaison J; Ngo, Kathy T; Viktorin, Gudrun

2015-10-01

Fixed lineages derived from unique, genetically specified neuroblasts form the anatomical building blocks of the Drosophila brain. Neurons belonging to the same lineage project their axons in a common tract, which is labeled by neuronal markers. In this paper, we present a detailed atlas of the lineage-associated tracts forming the brain of the early Drosophila larva, based on the use of global markers (anti-Neuroglian, anti-Neurotactin, inscuteable-Gal4>UAS-chRFP-Tub) and lineage-specific reporters. We describe 68 discrete fiber bundles that contain axons of one lineage or pairs/small sets of adjacent lineages. Bundles enter the neuropil at invariant locations, the lineage tract entry portals. Within the neuropil, these fiber bundles form larger fascicles that can be classified, by their main orientation, into longitudinal, transverse, and vertical (ascending/descending) fascicles. We present 3D digital models of lineage tract entry portals and neuropil fascicles, set into relationship to commonly used, easily recognizable reference structures such as the mushroom body, the antennal lobe, the optic lobe, and the Fasciclin II-positive fiber bundles that connect the brain and ventral nerve cord. Correspondences and differences between early larval tract anatomy and the previously described late larval and adult lineage patterns are highlighted. Our L1 neuro-anatomical atlas of lineages constitutes an essential step towards following morphologically defined lineages to the neuroblasts of the early embryo, which will ultimately make it possible to link the structure and connectivity of a lineage to the expression of genes in the particular neuroblast that gives rise to that lineage. Furthermore, the L1 atlas will be important for a host of ongoing work that attempts to reconstruct neuronal connectivity at the level of resolution of single neurons and their synapses. Copyright © 2015 Elsevier Inc. All rights reserved.

The Structural Role of Elastic Fibers in the Cornea Investigated Using a Mouse Model for Marfan Syndrome

PubMed Central

White, Tomas L.; Lewis, Philip; Hayes, Sally; Fergusson, James; Bell, James; Farinha, Luis; White, Nick S.; Pereira, Lygia V.; Meek, Keith M.

2017-01-01

Purpose The presence of fibrillin-rich elastic fibers in the cornea has been overlooked in recent years. The aim of the current study was to elucidate their functional role using a mouse model for Marfan syndrome, defective in fibrillin-1, the major structural component of the microfibril bundles that constitute most of the elastic fibers. Methods Mouse corneas were obtained from animals with a heterozygous fibrillin-1 mutation (Fbn1+/−) and compared to wild type controls. Corneal thickness and radius of curvature were calculated using optical coherence tomography microscopy. Elastic microfibril bundles were quantified and visualized in three-dimensions using serial block face scanning electron microscopy. Transmission electron microscopy was used to analyze stromal ultrastructure and proteoglycan distribution. Center-to-center average interfibrillar spacing was determined using x-ray scattering. Results Fbn1+/− corneas were significantly thinner than wild types and displayed a higher radius of curvature. In the Fbn1+/− corneas, elastic microfibril bundles were significantly reduced in density and disorganized compared to wild-type controls, in addition to containing a higher average center-to-center collagen interfibrillar spacing in the center of the cornea. No other differences were detected in stromal ultrastructure or proteoglycan distribution between the two groups. Proteoglycan side chains appeared to colocalize with the microfibril bundles. Conclusions Elastic fibers have an important, multifunctional role in the cornea as highlighted by the differences observed between Fbn1+/− and wild type animals. We contend that the presence of normal quantities of structurally organized elastic fibers are required to maintain the correct geometry of the cornea, which is disrupted in Marfan syndrome. PMID:28395026

Lower-Extremity Weakness in a Teenager Due to Thyrotoxic Periodic Paralysis.

PubMed

Thornton, Matthew D

2017-04-01

Thyrotoxic hypokalemic paralysis is the hallmark of thyrotoxic periodic paralysis (TPP). TPP is a potentially deadly complication of hyperthyroidism that occurs because of rapid and dramatic intracellular shift of potassium. This transference results in severe hypokalemia and clinically manifests itself as muscle weakness or paralysis. This condition predominantly affects males of Asian descent, and its presentation can range from mild to severe, as seen in our case. We present the case of a 15-year-old Asian-American male who presented to a tertiary-care pediatric emergency department complaining of generalized weakness and flaccid paralysis of his lower extremities. The differential for such a complaint is extremely broad, and the symptoms can result from etiologies arising from the cerebral cortex, the spinal cord, peripheral nerves, the neuromuscular junction, or even the muscles themselves. Our patient was found to have an extremely low serum potassium concentration, as well as an electrocardiogram that revealed a prolonged QT interval and right bundle branch block. The etiology of these abnormalities and the patient's symptoms was found to be undiagnosed and uncontrolled hyperthyroidism from Grave's disease, which resulted in this dramatic presentation of thyrotoxic hypokalemic paralysis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This entity is common in Asia but still somewhat rare in the United States and other Western countries. Our case illustrates that careful history taking and a focused diagnostic evaluation, in conjunction with having an awareness of this disease, can help expedite diagnosis and management, as well as avoid unnecessary and potential harmful testing in the emergency department setting. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic value of isoproterenol testing in arrhythmogenic right ventricular cardiomyopathy.

PubMed

Denis, Arnaud; Sacher, Frédéric; Derval, Nicolas; Lim, Han S; Cochet, Hubert; Shah, Ashok J; Daly, Matthew; Pillois, Xavier; Ramoul, Khaled; Komatsu, Yuki; Zemmoura, Adlane; Amraoui, Sana; Ritter, Philippe; Ploux, Sylvain; Bordachar, Pierre; Hocini, Mélèze; Jaïs, Pierre; Haïssaguerre, Michel

2014-08-01

Although the Task Force Criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) have recently been updated, the diagnosis remains challenging in the early stages. The aim of this study was to evaluate the diagnostic value of β-adrenergic stimulation in ARVC. We evaluated 412 consecutive patients (213 men, age 41.5±16 years) referred for premature ventricular contractions evaluation or suspected ARVC. Isoproterenol testing was performed with continuous infusion of isoproterenol (45 μg/min) for 3 minutes. It was considered positive if there were either (1) polymorphic premature ventricular contractions with ≥1 couplet or (2) sustained or nonsustained ventricular tachycardia with left bundle branch block excluding right ventricular outflow tract ventricular tachycardia. ARVC was diagnosed in 35 patients at initial evaluation (23 men, aged 42±15 years). Isoproterenol testing was positive in 32 of 35 (91.4%) patients with ARVC and in 42 of 377 (11.1%) patients without ARVC (P<0.0001). Sensitivity, specificity, positive, and negative predictive values of isoproterenol testing to diagnose ARVC were 91.4%, 88.9%, 43.2%, and 99.1%, respectively. During a mean follow-up period of 5.6±4.4 years, 6 additional patients met diagnostic criteria for ARVC. Importantly, initial isoproterenol testing was positive in 6 of 6 (100%) of these patients. Survival free from ARVC diagnosis was significantly lower in the positive isoproterenol group than in the negative isoproterenol group (P<0.0001, exact log-rank test). Ventricular arrhythmogenicity during isoproterenol testing is highly sensitive (sensitivity, 91.4%) for the diagnosis of ARVC, particularly in its early stages. © 2014 American Heart Association, Inc.

Electrocardiographic findings in athletes: the prevalence of left ventricular hypertrophy and conduction defects.

PubMed

Langdeau, J B; Blier, L; Turcotte, H; O'Hara, G; Boulet, L P

2001-06-01

To determine whether there are electrocardiographic differences or distinctive abnormalities between athletes and sedentary subjects, and to verify the relationship between vagal activity measured by heart rate variability (SD of all normal-to-normal intervals [SDNN]) and possible electrocardiographic abnormalities. Resting electrocardiograms and heart rate variability measurements were performed separately during a single visit on 100 athletes and 50 nonathlete control subjects aged 18 to 55 years. The athletes were from the following various sports disciplines: long-distance running, mountain biking, cross-country skiing, biathlon, speed skating, swimming and triathlon. There were significantly longer RR intervals, PR intervals and QT intervals in athletes than in control subjects (all P<0.05). The QRS complex and QTc did not show significant differences (both P>0.05). The prevalence of left ventricular hypertrophy (LVH) and incomplete right bundle branch block (IRBBB) was 10% and 7%, respectively, in athletes, but these conditions were absent in control subjects; among athletes, 2% presented with both conditions. LVH and IRBBB were more common among long-distance runners (six of 14 and four of 14, respectively) and could be attributed to normal, long term adaptation to intense, repeated exercise. LVH was related to age (P=0.04), whereas IRBBB was influenced by the number of years of training in the respective sports discipline (P=0.03). The mean SDNN value was significantly more elevated in athletes (P=0.0001), reflecting a higher parasympathetic tone than in sedentary control subjects. However, there was no relationship between vagal activity and LVH or IRBBB (both P>0.05).

Tailor-made heart simulation predicts the effect of cardiac resynchronization therapy in a canine model of heart failure.

PubMed

Panthee, Nirmal; Okada, Jun-ichi; Washio, Takumi; Mochizuki, Youhei; Suzuki, Ryohei; Koyama, Hidekazu; Ono, Minoru; Hisada, Toshiaki; Sugiura, Seiryo

2016-07-01

Despite extensive studies on clinical indices for the selection of patient candidates for cardiac resynchronization therapy (CRT), approximately 30% of selected patients do not respond to this therapy. Herein, we examined whether CRT simulations based on individualized realistic three-dimensional heart models can predict the therapeutic effect of CRT in a canine model of heart failure with left bundle branch block. In four canine models of failing heart with dyssynchrony, individualized three-dimensional heart models reproducing the electromechanical activity of each animal were created based on the computer tomographic images. CRT simulations were performed for 25 patterns of three ventricular pacing lead positions. Lead positions producing the best and the worst therapeutic effects were selected in each model. The validity of predictions was tested in acute experiments in which hearts were paced from the sites identified by simulations. We found significant correlations between the experimentally observed improvement in ejection fraction (EF) and the predicted improvements in ejection fraction (P<0.01) or the maximum value of the derivative of left ventricular pressure (P<0.01). The optimal lead positions produced better outcomes compared with the worst positioning in all dogs studied, although there were significant variations in responses. Variations in ventricular wall thickness among the dogs may have contributed to these responses. Thus CRT simulations using the individualized three-dimensional heart models can predict acute hemodynamic improvement, and help determine the optimal positions of the pacing lead. Copyright © 2016 Elsevier B.V. All rights reserved.

Integration of mechanical, structural and electrical imaging to understand response to cardiac resynchronization therapy.

PubMed

Silva, Etelvino; Bijnens, Bart; Berruezo, Antonio; Mont, Lluis; Doltra, Adelina; Andreu, David; Brugada, Josep; Sitges, Marta

2014-10-01

There is extensive controversy exists on whether cardiac resynchronization therapy corrects electrical or mechanical asynchrony. The aim of this study was to determine if there is a correlation between electrical and mechanical sequences and if myocardial scar has any relevant impact. Six patients with normal left ventricular function and 12 patients with left ventricular dysfunction and left bundle branch block, treated with cardiac resynchronization therapy, were studied. Real-time three-dimensional echocardiography and electroanatomical mapping were performed in all patients and, where applicable, before and after therapy. Magnetic resonance was performed for evaluation of myocardial scar. Images were postprocessed and mechanical and electrical activation sequences were defined and time differences between the first and last ventricular segment to be activated were determined. Response to therapy was defined as a reduction in left ventricular end-systolic volume ≥ 15% after 12 months of follow-up. Good correlation between electrical and mechanical timings was found in patients with normal left ventricular function (r(2) = 0.88; P = .005) but not in those with left ventricular dysfunction (r(2) = 0.02; P = not significant). After therapy, both timings and sequences were modified and improved, except in those with myocardial scar. Despite a close electromechanical relationship in normal left ventricular function, there is no significant correlation in patients with dysfunction. Although resynchronization therapy improves this correlation, the changes in electrical activation may not yield similar changes in left ventricular mechanics particularly depending on the underlying myocardial substrate. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Physical activity, opportunity for reinfection, and sibling history of heart disease as risk factors for Chagas' cardiopathy.

PubMed

Zicker, F; Smith, P G; Netto, J C; Oliveira, R M; Zicker, E M

1990-11-01

A case-control study was conducted to examine whether physical activity, sibling history of heart disease (HHD), and length of residence in an area endemic for Chagas' disease were associated with the risk of developing Chagas' cardiopathy. Two hundred forty-seven cases of Chagas' heart disease and 345 seropositive subjects with normal ECG (controls) were selected in a population survey in Goiânia, Brazil. Prevalence ratios for exposure variables were estimated for cases in relation to controls and for subgroups of seropositives with selected ECG abnormalities in relation to controls. Increasing age and male sex were consistently and significantly related to an increased risk of ECG abnormalities. HHD was significantly associated with ECG alterations in 3 of the 5 comparison subgroups (any ECG alteration, right bundle branch block, and left anterior hemiblock). No association was found between length of residence in an area endemic, physical activity, and ECG abnormalities. A sample of 529 seronegative subjects were also examined and the interaction between exposure variables and seropositivity was tested to assess whether the associations found were specific for seropositives. Males were at greater risk of any ECG alteration and left anterior hemiblock in relation to females if they were seropositive. An increasing risk of ventricular premature beats with age was clearer for seropositive than for seronegative subjects. Subjects with HHD were at an increased risk of ECG abnormalities and this was greater in those with a positive serological test (P less than 0.05). The findings suggest a possible geographical clustering or a familial aggregation of cases of Chagas' heart disease.

Prospective evaluation of eligibility for thrombolytic therapy in acute myocardial infarction.

PubMed Central

French, J. K.; Williams, B. F.; Hart, H. H.; Wyatt, S.; Poole, J. E.; Ingram, C.; Ellis, C. J.; Williams, M. G.; White, H. D.

1996-01-01

OBJECTIVES--To determine the proportion of patients presenting with acute myocardial infarction who are eligible for thrombolytic therapy. DESIGN--Cohort follow up study. SETTING--The four coronary care units in Auckland, New Zealand. SUBJECTS--All 3014 patients presenting to the units with suspected myocardial infarction in 1993. MAIN OUTCOME MEASURES--Eligibility for reperfusion with thrombolytic therapy (presentation within 12 hours of the onset of ischaemic chest pain with ST elevation > or = 2 mm in leads V1-V3, ST elevation > or = 1 mm in any other two contiguous leads, or new left bundle branch block); proportions of (a) patients eligible for reperfusion and (b) patients with contraindications to thrombolysis; death (including causes); definite myocardial infarction. RESULTS--948 patients had definite myocardial infarction, 124 probable myocardial infarction, and nine ST elevation but no infarction; 1274 patients had unstable angina and 659 chest pain of other causes. Of patients with definite or probable myocardial infarction, 576 (53.3%) were eligible for reperfusion, 39 had definite contraindications to thrombolysis (risk of bleeding). Hence 49.7% of patients (537/1081) were eligible for thrombolysis and 43.5% (470) received this treatment. Hospital mortality among patients eligible for reperfusion was 11.7% (55/470 cases) among those who received thrombolysis and 17.0% (18/106) among those who did not. CONCLUSIONS--On current criteria about half of patients admitted to coronary care units with definite or probable myocardial infarction are eligible for thrombolytic therapy. Few eligible patients have definite contraindications to thrombolytic therapy. Mortality for all community admissions for myocardial infarction remains high. PMID:8664716

Prevalence of Cardiovascular Disorders Among Iranian Elite Athletes.

PubMed

Salehi, Shahin; Moradi Shahpar, Farhad; Norouzi, Gholamreza; Ghazalian, Farshad; Poursaid Esfehani, Mehrshad; Abedi Yekta, Amir Hosein

2016-06-01

Athletes' health is an important issue and for promoting it, pre-participation examination (PPE) is widely performed by responsible bodies around the world. This study was to determine prevalence of cardiovascular disorders among athletes participating in the Asian games and answering the question whether the electrocardiogram (ECG) is a necessary part of pre-participation examination (PPE) for prevention of sudden cardiac death. All athletes participated at Asian games came to sports medicine federation for a PPE including a comprehensive questionnaire, physical examination and ECG. In this retrospective study all profiles of 338 athletes have been studied as well as their electrocardiograms. Multiple logistic regressions as well as Firth's bias reduction were used with R statistical software and SPSS. For predicting the changes in ECG, receiver operating characteristic (ROC) curve has done. Among 388 athletes, 80 (20.6%) were female and 308 (79.4%) male with mean age of 23.2 + 8 years. Nine athletes (2.3%) were smokers, 28 of them (7.2%) experienced chest pain and discomfort, 45 of them (13.3%) had palpitations and 28 (7.2%) had history of anemia. Study of their electrocardiograms showed that long Q-T interval was not seen for anyone, but evidence of left ventricular hypertrophy was seen in 12 (3.1%), inverted T wave in 6 (1.5%), and right bundle branch block in 45 (13.3%). PPE provides very important information of athletes' health. This study has shown that there was not any significant relation between current examination and electrocardiogram changes but regarding the ECG changes we recommend it as a routine part of PPE.

Feasibility, safety and efficacy of transcutaneous vagus nerve stimulation in chronic tinnitus: an open pilot study.

PubMed

Kreuzer, Peter M; Landgrebe, Michael; Resch, Markus; Husser, Oliver; Schecklmann, Martin; Geisreiter, Florian; Poeppl, Timm B; Prasser, Sarah J; Hajak, Goeran; Rupprecht, Rainer; Langguth, Berthold

2014-01-01

Vagus nerve stimulation represents an established treatment strategy for epilepsy and affective disorders. Recently, positive effects were also shown in animals and humans with tinnitus. Here we report the results of an open pilot study exploring feasibility, safety and efficacy of tVNS in the treatment of chronic tinnitus. Fifty patients with chronic tinnitus underwent tVNS in an open single-armed pilot study which was conducted in two phases applying two different stimulating devices (Cerbomed CM02 and NEMOS). Clinical assessment was based on Tinnitus Questionnaire (TQ), Tinnitus Handicap Inventory (THI), Beck Depression Inventory (BDI), WHO Quality of Life, and various numeric rating scales. Primary outcome was defined as change in TQ (baseline vs. final visit in week 24). The study has been registered with clinicaltrials.gov (NCT01176734). Primary analysis indicated mean TQ reductions of 3.7 points (phase 1) and 2.8 points (phase 2) significant for the first study phase. Secondary analyses indicated a significant BDI reduction for phase 1 (uncorrected for multiple testing), but no further systematic or significant effects. Adverse events included twitching and pressure at electrode placement site. The occurrence of one hospitalization because of palpations and the development of a left bundle branch block were considered as unrelated to the intervention. Cognitive testing revealed no significant changes. Our data demonstrate the feasibility of tVNS over a period of 6 months. There was no clinically relevant improvement of tinnitus complaints. Our data suggest tVNS to be considered safe in patients without a history of cardiac disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Are classic predictors of voltage valid in cardiac amyloidosis? A contemporary analysis of electrocardiographic findings.

PubMed

Sperry, Brett W; Vranian, Michael N; Hachamovitch, Rory; Joshi, Hariom; McCarthy, Meghann; Ikram, Asad; Hanna, Mazen

2016-07-01

Low voltage electrocardiography (ECG) coupled with increased ventricular wall thickness is the hallmark of cardiac amyloidosis. However, patient characteristics influencing voltage in the general population, including bundle branch block, have not been evaluated in amyloid heart disease. A retrospective analysis was performed of patients with newly diagnosed cardiac amyloidosis from 2002 to 2014. ECG voltage was calculated using limb (sum of QRS complex in leads I, II and III) and precordial (Sokolow: S in V1 plus R in V5-V6) criteria. The associations between voltage and clinical variables were tested using multivariable linear regression. A Cox model assessed the association of voltage with mortality. In 389 subjects (transthyretin ATTR 186, light chain AL 203), 30% had conduction delay (QRS >120ms). In those with narrow QRS, 68% met low limb, 72% low Sokolow and 57% both criteria, with lower voltages found in AL vs ATTR. LV mass index as well as other typical factors that impact voltage (age, sex, race, hypertension, BSA, and smoking) in the general population were not associated with voltage in this cardiac amyloidosis cohort. Patients with LBBB and IVCD had similar voltages when compared to those with narrow QRS. Voltage was significantly associated with mortality (p<0.001 for both criteria) after multivariable adjustment. Classic predictors of ECG voltage in the general population are not valid in cardiac amyloidosis. In this cohort, the prevalence estimates of ventricular conduction delay and low voltage are higher than previously reported. Voltage predicts mortality after multivariable adjustment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characteristics of Responders to Cardiac Resynchronization Therapy: The Impact of Echocardiographic Left Ventricular Volume

PubMed Central

Park, Mi Young; Altman, Robert K.; Orencole, Mary; Kumar, Prabhat; Parks, Kimberly A.; Heist, Kevin E.; Singh, Jagmeet P.; Picard, Michael H.

2012-01-01

Summary Background One third of patients who receive cardiac resynchronization therapy (CRT) are classified as nonresponders. Characteristics of responders to CRT have been studied in multiple clinical trials. Hypothesis We aimed to examine characteristics of CRT responders in a routine clinical practice. Method One hundred and twenty five patients were examined retrospectively from a multidisciplinary CRT clinic program. Echocardiographic CRT response was defined as a decrease in left ventricular (LV) end systolic volume (ESV) of ≥ 15% and/or absolute increase of 5% in LV ejection fraction (EF) at 6 month visit. Results There were 81 responders and 44 nonresponders. By univariate analyses, female gender, nonischemic cardiomyopathy etiology, baseline QRS duration, the presence of left bundle branch block (LBBB) and left ventricular end-diastolic volume (LVEDV) index predicted CRT response. However, multivariate analysis demonstrated only QRS duration, LBBB and LVEDV index were independent predictors (QRS width: Odd ratio [OR] 1.027, 95% CI 1.004 – 1.050, p = 0.023; LBBB: OR 3.568, 95% CI 1.284 – 9.910, p=0.015; LV EDV index: OR 0.970, 95% CI 0.953 – 0.987, p= 0.001). While female gender and nonischemic etiology were associated with an improved CRT response on univariate analyses, after adjusting for LV volumes, they were not independent predictors. Conclusion QRS width, LBBB and LVEDV index are independent predictors for echocardiographic CRT response. Previously reported differences in CRT response for gender and cardiomyopathy etiology are associated with differences in baseline LV volumes in our clinical practice. PMID:22886700

QRS Width as a Predictor of Right Ventricular Remodeling After Percutaneous Pulmonary Valve Implantation.

PubMed

Paech, C; Dähnert, I; Riede, F T; Wagner, R; Kister, T; Nieschke, K; Wagner, F; Gebauer, R A

2017-08-01

Recent data showed a right ventricular dyssynchrony in patients with tetralogy of Fallot (TOF). Percutaneous pulmonary valve implantation (PPVI) has become an important procedure to treat a pulmonary stenosis and/or regurgitation of the right ventricular outflow tract in these patients. Despite providing good results, there is still a considerable number of nonresponders to PPVI. The authors speculated that electrical dysfunction of the right ventricle plays an underestimated role in the outcome of patients after PPVI. This study aimed to investigate the influence of right ventricular electrical dysfunction, i.e., right bundle branch block (RBBB) on the RV remodeling after PPVI. The study included consecutive patients after correction of TOF with or without RBBB, who had received a PPVI previously at the Heart Center of the University of Leipzig, Germany during the period from 2012 to 2015. 24 patients were included. Patients without RBBB, i.e., with narrow QRS complexes pre-intervention, had significantly better RV function and had smaller right ventricular volumes. Patients with pre-interventionally QRS width below 150 ms showed a post-interventional remodeling of the right ventricle with the decreasing RV volumes (p = 0.001). The parameters of LV function and volume as well as RV ejection fraction remained unaffected by RBBB. The presented data indicate that the QRS width seems to be a valuable parameter in the prediction of right ventricular remodeling after PPVI, as it represents both electrical and mechanical functions of the right ventricle and may serve as an additional parameter for optimal timing of a PPVI.

Gender differences in symptoms of myocardial ischaemia.

PubMed

Mackay, Martha H; Ratner, Pamela A; Johnson, Joy L; Humphries, Karin H; Buller, Christopher E

2011-12-01

Better understanding of symptoms of myocardial ischaemia is needed to improve timeliness of treatment for acute coronary syndromes (ACS). Although researchers have suggested sex differences exist in ischaemic symptoms, methodological issues prevent conclusions. Using percutaneous coronary intervention (PCI) balloon inflation as a model of myocardial ischaemia, we explored sex differences in reported symptoms of ischaemia. Patients having non-emergent PCI, but not haemodynamic instability or left bundle branch block or non-acute coronary occlusion, were prospectively recruited. Pre-procedure, descriptions of pre-existing symptoms were obtained using open-ended questioning. Inflation was maintained for 2 min or until moderate discomfort or clinical instability occurred. During inflation, subjects were exhaustively questioned about their symptoms. Concurrent ECG data were collected. The final sample was 305 [39.7% women; mean age 63.9 (± 10.6)]. No sex differences were found in rates of chest or typical ischaemic discomfort, regardless of ischaemic status. Women were significantly more likely to report throat/jaw discomfort [odds ratio: 2.91; 95% confidence interval: 1.58-5.37] even after statistical adjustment for clinical and demographic variables. This prospective study with ECG-affirmed ischaemia found no statistically significant differences in women's and men's rates of chest and other typical symptoms during ischaemia, although women were more likely to experience throat and jaw discomfort. Currently both popular press and some patient education materials suggest women experience myocardial ischaemia differently from men. Steps to ensure women and health professionals are alert for the classic symptoms of myocardial ischaemia in women, as well as men, may be warranted.

[Cardiac resynchronization therapy for heart failure - from experimental pacing to evidence-based therapy].

PubMed

Götze, S; Butter, C; Fleck, E

2006-01-01

Within the last decade, cardiac resynchronization therapy (CRT) has become an evidence-based cornerstone for a subset of patients with chronic heart failure. For those, who suffer from ischemic or non-ischemic cardiomyopathies at NYHA III or IV, have sinus rhythm, a left bundle branch block and a left ventricular ejection fraction below 35%, CRT has evolved as an important treatment option with promising results. Numerous studies have shown that in these patients pacemaker-mediated correction of intra- and interventicular conduction disturbances can improve not only clinical symptoms, exercise tolerance and the frequency of hospitalizations, but even more important the overall mortality. These clinical results are due to several functional aspects. In the failing heart characteristic intra- and interventricular alterations in electrical conduction result in mechanical asynchrony that leads to an abnormal contraction of the left ventricle with delayed activation of the lateral wall, a paradoxical septal movement, a reduced diastolic filling and a mitral regurgitation due to dyssynchrony of papillary muscle activation. It is conceivable that these functional changes have fatal consequences for the failing heart. AV-optimized left- or biventricular stimulation by modern pacemakers can correct the pathological dyssynchrony, thereby improving cardiac function and clinical outcome in these patients. Although tremendous progress in cardiac resynchronization therapy has been made during the last decade, a couple of questions still need to be resolved. Critical issues are the identification of patients, who will predictably benefit from CRT, the value of CRT-pacemakers versus CRT-ICDs, and the usefullness of CRT in patients with atrial fibrillation.

Electrocardiographic Predictors of Long-Term Cardiac Pacing Dependency Following Transcatheter Aortic Valve Implantation.

PubMed

Naveh, Sivan; Perlman, Gidon Y; Elitsur, Yair; Planer, David; Gilon, Dan; Leibowitz, David; Lotan, Chaim; Danenberg, Haim; Alcalai, Ronny

2017-02-01

Conduction disorders requiring permanent pacemaker (PPM) implantation are a known complication of transcatheter aortic valve implantation (TAVI). Indications for permanent pacing in this setting are still controversial. The study aim was to characterize the natural history of conduction disorders related to TAVI, and to identify predictors for long-term pacing dependency. Consecutive patients who underwent TAVI were included in this prospective observational study. The conduction system was investigated by reviewing 12-lead ECGs during hospitalization and up to 1-year follow-up and by analyzing pacemaker interrogation data. Multivariate analysis was performed in order to identify independent predictors for pacemaker dependency. Of 110 patients included in the analysis, 38 (34.5%) underwent PPM implantation. Of those, 26 (68.4%) had a long-term pacing dependency (required PPM), while 12 (31.6%) did not (not-required PPM). Logistic regression revealed that baseline RBBB (P = 0.01, OR = 18.0), baseline PR interval (P = 0.019, OR = 1.14), post-TAVI PR interval and the change in PR interval from baseline (P < 0.001 for both, OR = 1.17 for each 10 milliseconds increment) were independent predictors for long-term pacing dependency. A PR interval increment of greater than 28 milliseconds had the best accuracy in predicting pacemaker dependency. Increased pre- and postprocedural PR intervals and pre-existing RBBB are reliable predictors for long-term PPM dependency, while left bundle branch block or QRS width are misleading factors. Our study suggests that the decision for implanting PPM after TAVI should be based mostly on the prolongation of the PR interval. © 2016 Wiley Periodicals, Inc.

The zebrafish as a novel animal model to study the molecular mechanisms of mechano-electrical feedback in the heart

PubMed Central

Werdich, Andreas A; Brzezinski, Anna; Jeyaraj, Darwin; Ficker, Eckhard; Wan, Xiaoping; McDermott, Brian M; Sabeh, M Khaled; MacRae, Calum A; Rosenbaum, David S

2013-01-01

Altered mechanical loading of the heart leads to hypertrophy, decompensated heart failure and fatal arrhythmias. However, the molecular mechanisms that link mechanical and electrical dysfunction remain poorly understood. Growing evidence suggest that ventricular electrical remodeling (VER) is a process that can be induced by altered mechanical stress, creating persistent electrophysiological changes that predispose the heart to life-threatening arrhythmias. While VER is clearly a physiological property of the human heart, as evidenced by “T wave memory”, it is also thought to occur in a variety of pathological states associated with altered ventricular activation such as bundle branch block, myocardial infarction, and cardiac pacing. Animal models that are currently being used for investigating stretch-induced VER have significant limitations. The zebrafish has recently emerged as an attractive animal model for studying cardiovascular disease and could overcome some of these limitations. Owing to its extensively sequenced genome, high conservation of gene function, and the comprehensive genetic resources that are available in this model, the zebrafish may provide new insights into the molecular mechanisms that drive detrimental electrical remodeling in response to stretch. Here, we have established a zebrafish model to study mechano-electrical feedback in the heart, which combines efficient genetic manipulation with high-precision stretch and high-resolution electrophysiology. In this model, only ninety minutes of ventricular stretch caused VER and recapitulated key features of VER found previously in the mammalian heart. Our data suggest that the zebrafish model is a powerful platform for investigating the molecular mechanisms underlying mechano-electrical feedback and VER in the heart. PMID:22835662

Sustained Performance of a "Physicianless" System of Automated Prehospital STEMI Diagnosis and Catheterization Laboratory Activation.

PubMed

Potter, Brian J; Matteau, Alexis; Mansour, Samer; Naim, Charbel; Riahi, Mounir; Essiambre, Richard; Montigny, Martine; Sareault, Isabelle; Gobeil, François

2017-01-01

Treatment times for primary percutaneous coronary intervention frequently exceed the recommended maximum delay. Automated "physicianless" systems of prehospital cardiac catheterization laboratory (CCL) activation show promise, but have been met with resistance over concerns regarding the potential for false positive and inappropriate activations (IAs). From 2010 to 2015, first responders performed electrocardiograms (ECGs) in the field for all patients with a complaint of chest pain or dyspnea. An automated machine diagnosis of "acute myocardial infarction" resulted in immediate CCL activation and direct transfer without transmission or human reinterpretation of the ECG prior to patient arrival. Any activation resulting from a nondiagnostic ECG (no ST-elevation) was deemed an IA, whereas activations resulting from ECG's compatible with ST-elevation myocardial infarction but without angiographic evidence of a coronary event were deemed false positive. In 2012, the referral algorithm was modified to exclude supraventricular tachycardia and left bundle branch block. There were 155 activations in the early cohort (2010-2012; prior to algorithm modification) and 313 in the late cohort (2012-2015). Algorithm modification resulted in a 42% relative decrease in the rate of IAs (12% vs 7%; P < 0.01) without a significant effect on treatment delay. A combination of prehospital automated ST-elevation myocardial infarction diagnosis and "physicianless" CCL activation is safe and effective in improving treatment delay and these results are sustainable over time. The performance of the referral algorithm in terms of IA and false positive is at least on par with systems that ensure real-time human oversight. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Detection of Cardiac Abnormalities from Multilead ECG using Multiscale Phase Alternation Features.

PubMed

Tripathy, R K; Dandapat, S

2016-06-01

The cardiac activities such as the depolarization and the relaxation of atria and ventricles are observed in electrocardiogram (ECG). The changes in the morphological features of ECG are the symptoms of particular heart pathology. It is a cumbersome task for medical experts to visually identify any subtle changes in the morphological features during 24 hours of ECG recording. Therefore, the automated analysis of ECG signal is a need for accurate detection of cardiac abnormalities. In this paper, a novel method for automated detection of cardiac abnormalities from multilead ECG is proposed. The method uses multiscale phase alternation (PA) features of multilead ECG and two classifiers, k-nearest neighbor (KNN) and fuzzy KNN for classification of bundle branch block (BBB), myocardial infarction (MI), heart muscle defect (HMD) and healthy control (HC). The dual tree complex wavelet transform (DTCWT) is used to decompose the ECG signal of each lead into complex wavelet coefficients at different scales. The phase of the complex wavelet coefficients is computed and the PA values at each wavelet scale are used as features for detection and classification of cardiac abnormalities. A publicly available multilead ECG database (PTB database) is used for testing of the proposed method. The experimental results show that, the proposed multiscale PA features and the fuzzy KNN classifier have better performance for detection of cardiac abnormalities with sensitivity values of 78.12 %, 80.90 % and 94.31 % for BBB, HMD and MI classes. The sensitivity value of proposed method for MI class is compared with the state-of-art techniques from multilead ECG.

Predictors of Total Mortality and Echocardiographic Response for Cardiac Resynchronization Therapy: A Cohort Study

PubMed Central

Gazzoni, Guilherme Ferreira; Fraga, Matheus Bom; Ferrari, Andres Di Leoni; Soliz, Pablo da Costa; Borges, Anibal Pires; Bartholomay, Eduardo; Kalil, Carlos Antonio Abunader; Giaretta, Vanessa; Rohde, Luis Eduardo Paim

2017-01-01

Background Clinical studies demonstrate that up to 40% of patients do not respond to cardiac resynchronization therapy (CRT), thus, appropriate patient selection is critical to the success of CRT in heart failure. Objective Evaluation of mortality predictors and response to CRT in the Brazilian scenario. Methods Retrospective cohort study including patients submitted to CRT in a tertiary hospital in southern Brazil from 2008 to 2014. Survival was assessed through a database of the State Department of Health (RS). Predictors of echocardiographic response were evaluated using Poisson regression. Survival analysis was performed by Cox regression and Kaplan Meyer curves. A two-tailed p value less than 0.05 was considered statistically significant. Results A total of 170 patients with an average follow-up of 1011 ± 632 days were included. The total mortality was 30%. The independent predictors of mortality were age (hazard ratio [HR] of 1.05, p = 0.027), previous acute myocardial infarction (AMI) (HR of 2.17, p = 0.049) and chronic obstructive pulmonary disease (COPD) (HR of 3.13, p = 0.015). The percentage of biventricular stimulation at 6 months was identified as protective factor of mortality ([HR] 0.97, p = 0.048). The independent predictors associated with the echocardiographic response were absence of mitral insufficiency, presence of left bundle branch block and percentage of biventricular stimulation. Conclusion Mortality in patients submitted to CRT in a tertiary hospital was independently associated with age, presence of COPD and previous AMI. The percentage of biventricular pacing evaluated 6 months after resynchronizer implantation was independently associated with improved survival and echocardiographic response. PMID:29185615

Hierarchical self-assembly, coassembly, and self-organization of novel liquid crystalline lattices and superlattices from a twin-tapered dendritic benzamide and its four-cylinder-bundle supramolecular polymer.

PubMed

Percec, Virgil; Bera, Tushar K; Glodde, Martin; Fu, Qiongying; Balagurusamy, Venkatachalapathy S K; Heiney, Paul A

2003-02-17

The synthesis and structural analysis of the twin-dendritic benzamide 10, based on the first-generation, self-assembling, tapered dendrons 3,4,5-tris(4'-dodecyloxybenzyloxy)benzoic acid and 3,4,5-tris(4'-dodecyloxybenzyloxy)-1-aminobenzene, and the polymethacrylate, 20, which contains 10 as side groups, are presented. Benzamide 10 self-assembles into a supramolecular cylindrical dendrimer that self-organizes into a columnar hexagonal (Phi(h)) liquid crystalline (LC) phase. Polymer 20 self-assembles into an imperfect four-cylinder-bundle supramolecular dendrimer, and creates a giant vesicular supercylinder that self-organizes into a columnar nematic (N(c)) LC phase which displays short-range hexagonal order. In mixtures of 20 and 10, 10 acts as a guest and 20 as a host to create a perfect four-cylinder-bundle host-guest supramolecular dendrimer that coorganizes with 10. A diversity of Phi(h), simple rectangular columnar (Phi(r-s)) and centered rectangular columnar (Phi(r-c)), superlattices are produced at different ratios between 20 and 10. This diversity of LC lattices and superlattices is facilitated by the architecture of the twin-dendritic building block, polymethacrylate, the host-guest supramolecular assembly, and by hydrogen bonding along the center of the supramolecular cylinders generated from 10 and 20.

A new building block for DNA network formation by self-assembly and polymerase chain reaction.

PubMed

Bußkamp, Holger; Keller, Sascha; Robotta, Marta; Drescher, Malte; Marx, Andreas

2014-01-01

The predictability of DNA self-assembly is exploited in many nanotechnological approaches. Inspired by naturally existing self-assembled DNA architectures, branched DNA has been developed that allows self-assembly to predesigned architectures with dimensions on the nanometer scale. DNA is an attractive material for generation of nanostructures due to a plethora of enzymes which modify DNA with high accuracy, providing a toolbox for many different manipulations to construct nanometer scaled objects. We present a straightforward synthesis of a rigid DNA branching building block successfully used for the generation of DNA networks by self-assembly and network formation by enzymatic DNA synthesis. The Y-shaped 3-armed DNA construct, bearing 3 primer strands is accepted by Taq DNA polymerase. The enzyme uses each arm as primer strand and incorporates the branched construct into large assemblies during PCR. The networks were investigated by agarose gel electrophoresis, atomic force microscopy, dynamic light scattering, and electron paramagnetic resonance spectroscopy. The findings indicate that rather rigid DNA networks were formed. This presents a new bottom-up approach for DNA material formation and might find applications like in the generation of functional hydrogels.

Distribution of radiodense contrast medium after perineural injection of the palmar and palmar metacarpal nerves (low 4-point nerve block): an in vivo and ex vivo study in horses.

PubMed

Nagy, A; Bodò, G; Dyson, S J; Compostella, F; Barr, A R S

2010-09-01

Evidence-based information is limited on distribution of local anaesthetic solution following perineural analgesia of the palmar (Pa) and palmar metacarpal (PaM) nerves in the distal aspect of the metacarpal (Mc) region ('low 4-point nerve block'). To demonstrate the potential distribution of local anaesthetic solution after a low 4-point nerve block using a radiographic contrast model. A radiodense contrast medium was injected subcutaneously over the medial or the lateral Pa nerve at the junction of the proximal three-quarters and distal quarter of the Mc region (Pa injection) and over the ipsilateral PaM nerve immediately distal to the distal aspect of the second or fourth Mc bones (PaM injection) in both forelimbs of 10 mature horses free from lameness. Radiographs were obtained 0, 10 and 20 min after injection and analysed subjectively and objectively. Methylene blue and a radiodense contrast medium were injected in 20 cadaver limbs using the same techniques. Radiographs were obtained and the limbs dissected. After 31/40 (77.5%) Pa injections, the pattern of the contrast medium suggested distribution in the neurovascular bundle. There was significant proximal diffusion with time, but the main contrast medium patch never progressed proximal to the mid-Mc region. The radiological appearance of 2 limbs suggested that contrast medium was present in the digital flexor tendon sheath (DFTS). After PaM injections, the contrast medium was distributed diffusely around the injection site in the majority of the limbs. In cadaver limbs, after Pa injections, the contrast medium and the dye were distributed in the neurovascular bundle in 8/20 (40%) limbs and in the DFTS in 6/20 (30%) of limbs. After PaM injections, the contrast and dye were distributed diffusely around the injection site in 9/20 (45%) limbs and showed diffuse and tubular distribution in 11/20 (55%) limbs. Proximal diffusion of local anaesthetic solution after a low 4-point nerve block is unlikely to be responsible for decreasing lameness caused by pain in the proximal Mc region. The DFTS may be penetrated inadvertently when performing a low 4-point nerve block.

Transthoracic Arteriovenous Graft Repair With the Pectoralis (PECS) II Nerve Block for Primary Intraoperative Anesthesia and Postoperative Analgesia: A Case Report.

PubMed

Farkas, Gabriel; Weber, Garret; Miller, Jonathon; Xu, Jeff

2018-05-07

The PECS II nerve block is a relatively new regional anesthetic technique that targets the medial and lateral pectoral nerves, as well as the lateral cutaneous branches of the intercostal nerves. It has been described for surgical cases involving the breast, as an adjunct or alternative to neuraxial or paravertebral techniques. This case report describes the first successful use of the PECS II nerve block placed using ultrasound guidance as the primary anesthetic and postoperative analgesic in a non-breast-related chest wall surgery.

Icing Branch Current Research Activities in Icing Physics

NASA Technical Reports Server (NTRS)

Vargas, Mario

2009-01-01

Current development: A grid block transformation scheme which allows the input of grids in arbitrary reference frames, the use of mirror planes, and grids with relative velocities has been developed. A simple ice crystal and sand particle bouncing scheme has been included. Added an SLD splashing model based on that developed by William Wright for the LEWICE 3.2.2 software. A new area based collection efficiency algorithm will be incorporated which calculates trajectories from inflow block boundaries to outflow block boundaries. This method will be used for calculating and passing collection efficiency data between blade rows for turbo-machinery calculations.

Hair cell recovery in mitotically blocked cultures of the bullfrog saccule

NASA Technical Reports Server (NTRS)

Baird, R. A.; Burton, M. D.; Fashena, D. S.; Naeger, R. A.

2000-01-01

Hair cells in many nonmammalian vertebrates are regenerated by the mitotic division of supporting cell progenitors and the differentiation of the resulting progeny into new hair cells and supporting cells. Recent studies have shown that nonmitotic hair cell recovery after aminoglycoside-induced damage can also occur in the vestibular organs. Using hair cell and supporting cell immunocytochemical markers, we have used confocal and electron microscopy to examine the fate of damaged hair cells and the origin of immature hair cells after gentamicin treatment in mitotically blocked cultures of the bullfrog saccule. Extruding and fragmenting hair cells, which undergo apoptotic cell death, are replaced by scar formations. After losing their bundles, sublethally damaged hair cells remain in the sensory epithelium for prolonged periods, acquiring supporting cell-like morphology and immunoreactivity. These modes of damage appear to be mutually exclusive, implying that sublethally damaged hair cells repair their bundles. Transitional cells, coexpressing hair cell and supporting cell markers, are seen near scar formations created by the expansion of neighboring supporting cells. Most of these cells have morphology and immunoreactivity similar to that of sublethally damaged hair cells. Ultrastructural analysis also reveals that most immature hair cells had autophagic vacuoles, implying that they originated from damaged hair cells rather than supporting cells. Some transitional cells are supporting cells participating in scar formations. Supporting cells also decrease in number during hair cell recovery, supporting the conclusion that some supporting cells undergo phenotypic conversion into hair cells without an intervening mitotic event.

Hair cell recovery in mitotically blocked cultures of the bullfrog saccule

PubMed Central

Baird, Richard A.; Burton, Miriam D.; Fashena, David S.; Naeger, Rebecca A.

2000-01-01

Hair cells in many nonmammalian vertebrates are regenerated by the mitotic division of supporting cell progenitors and the differentiation of the resulting progeny into new hair cells and supporting cells. Recent studies have shown that nonmitotic hair cell recovery after aminoglycoside-induced damage can also occur in the vestibular organs. Using hair cell and supporting cell immunocytochemical markers, we have used confocal and electron microscopy to examine the fate of damaged hair cells and the origin of immature hair cells after gentamicin treatment in mitotically blocked cultures of the bullfrog saccule. Extruding and fragmenting hair cells, which undergo apoptotic cell death, are replaced by scar formations. After losing their bundles, sublethally damaged hair cells remain in the sensory epithelium for prolonged periods, acquiring supporting cell-like morphology and immunoreactivity. These modes of damage appear to be mutually exclusive, implying that sublethally damaged hair cells repair their bundles. Transitional cells, coexpressing hair cell and supporting cell markers, are seen near scar formations created by the expansion of neighboring supporting cells. Most of these cells have morphology and immunoreactivity similar to that of sublethally damaged hair cells. Ultrastructural analysis also reveals that most immature hair cells had autophagic vacuoles, implying that they originated from damaged hair cells rather than supporting cells. Some transitional cells are supporting cells participating in scar formations. Supporting cells also decrease in number during hair cell recovery, supporting the conclusion that some supporting cells undergo phenotypic conversion into hair cells without an intervening mitotic event. PMID:11050201

Hair cell recovery in mitotically blocked cultures of the bullfrog saccule.

PubMed

Baird, R A; Burton, M D; Lysakowski, A; Fashena, D S; Naeger, R A

2000-10-24

Hair cells in many nonmammalian vertebrates are regenerated by the mitotic division of supporting cell progenitors and the differentiation of the resulting progeny into new hair cells and supporting cells. Recent studies have shown that nonmitotic hair cell recovery after aminoglycoside-induced damage can also occur in the vestibular organs. Using hair cell and supporting cell immunocytochemical markers, we have used confocal and electron microscopy to examine the fate of damaged hair cells and the origin of immature hair cells after gentamicin treatment in mitotically blocked cultures of the bullfrog saccule. Extruding and fragmenting hair cells, which undergo apoptotic cell death, are replaced by scar formations. After losing their bundles, sublethally damaged hair cells remain in the sensory epithelium for prolonged periods, acquiring supporting cell-like morphology and immunoreactivity. These modes of damage appear to be mutually exclusive, implying that sublethally damaged hair cells repair their bundles. Transitional cells, coexpressing hair cell and supporting cell markers, are seen near scar formations created by the expansion of neighboring supporting cells. Most of these cells have morphology and immunoreactivity similar to that of sublethally damaged hair cells. Ultrastructural analysis also reveals that most immature hair cells had autophagic vacuoles, implying that they originated from damaged hair cells rather than supporting cells. Some transitional cells are supporting cells participating in scar formations. Supporting cells also decrease in number during hair cell recovery, supporting the conclusion that some supporting cells undergo phenotypic conversion into hair cells without an intervening mitotic event.

24. Perspective view of central tower from roof of main ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. Perspective view of central tower from roof of main block, looking northeast, with HABS team - National Home for Disabled Volunteer Soldiers, Northwestern Branch, Main Building, 5000 West National Avenue, Milwaukee, Milwaukee County, WI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolton, Justin; Rzayev, Javid

Polystyrene–poly(methyl methacrylate)–polylactide (PS–PMMA–PLA) triblock bottlebrush copolymer with nearly symmetric volume fractions was synthesized by grafting from a symmetrical triblock backbone and the resulting melt was characterized by scanning electron microscopy and small-angle X-ray scattering. The copolymer backbone was prepared by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization of solketal methacrylate (SM), 2-(bromoisobutyryl)ethyl methacrylate (BIEM), and 5-(trimethylsilyl)-4-pentyn-1-ol methacrylate (TPYM). PMMA branches were grafted by atom transfer radical polymerization from the poly(BIEM) segment, PS branches were grafted by RAFT polymerization from the poly(TPYM) block after installment of the RAFT agents, while PLA side chains were grafted from the deprotected poly(SM) block. Themore » resulting copolymer was found to exhibit a lamellae morphology with a domain spacing of 79 nm. Differential scanning calorimetry analysis indicated that PMMA was preferentially mixing with PS while phase separating from PLA domains.« less

Enhancement of L-valine production in Bacillus licheniformis by blocking three branched pathways.

PubMed

Liang, Chengwen; Huo, Yanli; Qi, Gaofu; Wei, Xuetuan; Wang, Qin; Chen, Shouwen

2015-06-01

Bacillus licheniformis WX-02 is used for the production of many valuable chemicals. Here, we have sought to improve L-valine production by blocking the metabolic pathways related to branched-chain amino acids. The synthesis genes of L-leucine (leuA) and L-isoleucine (ilvA) were deleted to obtain mutant strains. L-Valine yields of WX-02ΔleuA and WX-02ΔilvA reached 33.2 and 21.1 mmol/l, respectively, which are 22 and 14 times higher than the wild-type WX-02 (1.53 mmol/l). After further deletion of L-lactate dehydrogenase gene (ldh) from WX-02ΔleuA, the productivity reached 0.47 mmol/l h, an increase of 19 %. We provide a possibility to over-produce L-valine using genetically-modified B. licheniformis using remodeling of the biosynthetic pathway to L-valine.

Influence of blue light on the leaf morphoanatomy of in vitro Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae).

PubMed

Leal-Costa, Marcos Vinicius; Nascimento, Luana Beatriz dos Santos; Moreira, Nattacha dos Santos; Reinert, Fernanda; Costa, Sônia Soares; Lage, Celso Luiz Salgueiro; Tavares, Eliana Schwartz

2010-10-01

Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) (air plant, miracle leaf) is popularly used to treat gastrointestinal disorders and wounds. Recently, the species was tested to treat cutaneous leishmaniasis with successful results. This medicinal activity was associated with the phenolic fraction of the plant. Blue light induces biosynthesis of phenolic compounds and many changes in anatomical characteristics. We studied the effects of supplementary blue light on the leaf morphology of in vitro K. pinnata. Plants cultured under white light (W plants) only and white light plus blue light (WB plants) show petioles with plain-convex section, amphistomatic leaf blades with simple epidermis, homogeneous mesophyll with densely packed cells, and a single collateral vascular bundle in the midrib. W plants have longer branches, a larger number of nodes per branch, and smaller leaves, whereas WB plant leaves have a thicker upper epidermis and mesophyll. Leaf fresh weight and leaf dry weight were similar in both treatments. Phenolic idioblasts were observed in the plants supplemented with blue light, suggesting that blue light plays an important role in the biosynthesis of phenolic compounds in K. pinnata.

[Anatomical planes and landmarks of transanal total mesorectal excision for rectal cancer and prophylaxis of intraoperative complications].

PubMed

Shen, Zhanlong; Ye, Yingjiang; Wang, Shan

2017-07-25

Total mesorectal excision (TME) is a mile-stone procedure in the history of rectal cancer surgery, but the exposure of surgical field of distal rectum is usually poor in patients with male, obese and narrow pelvis, which may lead to tumor residue and relative complications. Recently, a new technique called transanal TME (taTME) is considered to solve the above problems, but most medical centers are still in the learning curve of this procedure. Therefore, anatomical planes and landmarks of taTME for rectal cancer and prophylaxis of intraoperative complications are induced in this paper, which includes posterior plane: angle of anus and distal mesorectum and bleeding of mesorectum; rectosacral fascia and presacral bleeding; lateral and posterior-lateral plane: posterior branches of pelvic plexus and damage of anal function; anterior plane: vessel branches of neurovascular bundle and bleeding. Familiarity with the specific anatomical planes and landmarks plays an important role in shortening the learning curve, decreasing the complications, increasing the success rate of operation and standardization of taTME.

Rayleigh Wave Phase Velocities Beneath the Central and Southern East African Rift System

NASA Astrophysics Data System (ADS)

Adams, A. N.; Miller, J. C.

2017-12-01

This study uses the Automated Generalized Seismological Data Function (AGSDF) method to develop a model of Rayleigh wave phase velocities in the central and southern portions of the East African Rift System (EARS). These phase velocity models at periods of 20-100s lend insight into the lithospheric structures associated with surficial rifting and volcanism, as well as basement structures that pre-date and affect the course of rifting. A large dataset of >700 earthquakes is used, comprised of Mw=6.0+ events that occurred between the years 1995 and 2016. These events were recorded by a composite array of 176 stations from twelve non-contemporaneous seismic networks, each with a distinctive array geometry and station spacing. Several first-order features are resolved in this phase velocity model, confirming findings from previous studies. (1) Low velocities are observed in isolated regions along the Western Rift Branch and across the Eastern Rift Branch, corresponding to areas of active volcanism. (2) Two linear low velocity zones are imaged trending southeast and southwest from the Eastern Rift Branch in Tanzania, corresponding with areas of seismic activity and indicating possible incipient rifting. (3) High velocity regions are observed beneath both the Tanzania Craton and the Bangweulu Block. Furthermore, this model indicates several new findings. (1) High velocities beneath the Bangweulu Block extend to longer periods than those found beneath the Tanzania Craton, perhaps indicating that rifting processes have not altered the Bangweulu Block as extensively as the Tanzania Craton. (2) At long periods, the fast velocities beneath the Bangweulu Block extend eastwards beyond the surficial boundaries, to and possibly across the Malawi Rift. This may suggest the presence of older, thick blocks of lithosphere in regions where they are not exposed at the surface. (3) Finally, while the findings of this study correspond well with previous studies in regions of overlapping data, the greatest deviations, as well as the highest standard deviation in measurements, are found in volcanically active regions characterized by high anisotropy, suggesting that the influence of seismic anisotropy may have vary significantly between tomography methods.

Kinematics of the southern Red Sea-Afar Triple Junction and implications for plate dynamics

NASA Astrophysics Data System (ADS)

McClusky, Simon; Reilinger, Robert; Ogubazghi, Ghebrebrhan; Amleson, Aman; Healeb, Biniam; Vernant, Philippe; Sholan, Jamal; Fisseha, Shimelles; Asfaw, Laike; Bendick, Rebecca; Kogan, Lewis

2010-03-01

GPS measurements adjacent to the southern Red Sea and Afar Triple Junction, indicate that the Red Sea Rift bifurcates south of 17° N latitude with one branch following a continuation of the main Red Sea Rift (˜150° Az.) and the other oriented more N-S, traversing the Danakil Depression. These two rift branches account for the full Arabia-Nubia relative motion. The partitioning of extension between rift branches varies approximately linearly along strike; north of ˜16°N latitude, extension (˜15 mm/yr) is all on the main Red Sea Rift while at ˜13°N, extension (˜20 mm/yr) has transferred completely to the Danakil Depression. The Danakil Block separates the two rifts and rotates in a counterclockwise sense with respect to Nubia at a present-day rate of 1.9 ± 0.1°/Myr around a pole located at 17.0 ± 0.2°N, 39.7 ± 0.2°E, accommodating extension along the rifts and developing the roughly triangular geometry of the Danakil Depression. Rotating the Danakil Block back in time to close the Danakil Depression, and assuming that the rotation rate with respect to Nubia has been roughly constant, the present width of the Danakil Depression is consistent with initiation of block rotation at 9.3 ± 4 Ma, approximately coincident with the initiation of ocean spreading in the Gulf of Aden, and a concomitant ˜70% increase in the rate of Nubia-Arabia relative motion.

Dystrophic Serotonergic Axons in Neurodegenerative Diseases

PubMed Central

Azmitia, Efrain C.; Nixon, Ralph

2012-01-01

Neurodegenerative diseases such as Parkinson's disease (PD), frontal lobe dementia (FLD) and Diffuse Lewy-Body dementia (DLBD) have diverse neuropathologic features. Here we report that serotonin fibers are dystrophic in the brains of individuals with these three diseases. In neuropathologically normal (control) brains (n=3), serotonin axons immunoreactive (IR) with antibodies against the serotonin transporter (5-HTT) protein were widely distributed in cortex (entorhinal and dorsolateral prefrontal), hippocampus and rostral brainstem. 5-HTT-IR fibers of passage appeared thick, smooth, and un-branched in medial forebrain bundle, medial lemniscus and cortex white matter. The terminal branches were fine, highly branched and varicose in substantia nigra, hippocampus and cortical gray matter. In the diseased brains, however, 5-HTT-IR fibers in the forebrain were reduced in number and were frequently bulbous, splayed, tightly clustered and enlarged. Morphometric analysis revealed significant differences in the size distribution of the 5-HTT-IR profiles in dorsolateral prefrontal area between neurodegenerative diseases and controls. Our observations provide direct morphologic evidence for degeneration of human serotonergic axons in the brains of patients with neurodegenerative diseases despite the limited size (n=3 slices for each region (3) from each brain (4), total slices was n=36) and lack of extensive clinical characterization of the analyzed cohort. This is the first report of dystrophic 5-HTT-IR axons in postmortem human tissue PMID:18502405

A vector-free ECG interpretation with P, QRS & T waves as unbalanced transitions between stable configurations of the heart electric field during P-R, S-T & T-P segments

PubMed Central

2014-01-01

Since cell membranes are weak sources of electrostatic fields, this ECG interpretation relies on the analogy between cells and electrets. It is here assumed that cell-bound electric fields unite, reach the body surface and the surrounding space and form the thoracic electric field that consists from two concentric structures: the thoracic wall and the heart. If ECG leads measure differences in electric potentials between skin electrodes, they give scalar values that define position of the electric field center along each lead. Repolarised heart muscle acts as a stable positive electric source, while depolarized heart muscle produces much weaker negative electric field. During T-P, P-R and S-T segments electric field is stable, only subtle changes are detectable by skin electrodes. Diastolic electric field forms after ventricular depolarization (T-P segments in the ECG recording). Telediastolic electric field forms after the atria have been depolarized (P-Q segments in the ECG recording). Systolic electric field forms after the ventricular depolarization (S-T segments in the ECG recording). The three ECG waves (P, QRS and T) can then be described as unbalanced transitions of the heart electric field from one stable configuration to the next and in that process the electric field center is temporarily displaced. In the initial phase of QRS, the rapidly diminishing septal electric field makes measured potentials dependent only on positive charges of the corresponding parts of the left and the right heart that lie within the lead axes. If more positive charges are near the "DOWN" electrode than near the "UP" electrode, a Q wave will be seen, otherwise an R wave is expected. Repolarization of the ventricular muscle is dampened by the early septal muscle repolarization that reduces deflection of T waves. Since the "UP" electrode of most leads is near the usually larger left ventricle muscle, T waves are in these leads positive, although of smaller amplitude and longer duration than the QRS wave in the same lead. The proposed interpretation is applied to bundle branch blocks, fascicular (hemi-) blocks and changes during heart muscle ischemia. PMID:24506945

Highly-branched anisotropic hybrid nanoparticles at surfaces.

NASA Astrophysics Data System (ADS)

Tsukruk, Vladimir

2009-03-01

We present a brief overview of our recent studies on combined hybrid anisotropic structures composed of inorganic nanoparticles and highly branched molecules such as modified silsesquioxanes polyhedra cores (POSS) with mixed hydrophobic-hydrophilic tails and silver nanowires with functionalized star block copolymer with embedded gold nanoparticles (nanocobs). We demonstrate two-stage melting of that branched POSS and their ability to form monolayer and multilayered LB structures. On the other hand, we observed that silver-BCP-gold nanocobs display extremely bright Raman scattering caused by surface enhanced Raman effect with very different longitudinal and transversal optical properties as revealed by high-resolution confocal Raman microscopy. To study these hybrid nanostructures we applied combined AFM, SEM, TEM, XPS, SERS, UV-vis, and XR techniques.

Stable, polymer-directed and SPION-nucleated magnetic amphiphilic block copolymer nanoprecipitates with readily reversible assembly in magnetic fields

NASA Astrophysics Data System (ADS)

Giardiello, Marco; Hatton, Fiona L.; Slater, Rebecca A.; Chambon, Pierre; North, Jocelyn; Peacock, Anita K.; He, Tao; McDonald, Tom O.; Owen, Andrew; Rannard, Steve P.

2016-03-01

The formation of inorganic-organic magnetic nanocomposites using reactive chemistry often leads to a loss of super-paramagnetisim when conducted in the presence of iron oxide nanoparticles. We present here a low energy and chemically-mild process of co-nanoprecipitation using SPIONs and homopolymers or amphiphilic block copolymers, of varying architecture and hydrophilic/hydrophobic balance, which efficiently generates near monodisperse SPION-containing polymer nanoparticles with complete retention of magnetism, and highly reversible aggregation and redispersion behaviour. When linear and branched block copolymers with inherent water-solubility are used, a SPION-directed nanoprecipitation mechanism appears to dominate the nanoparticle formation presenting new opportunities for tailoring and scaling highly functional systems for a range of applications.The formation of inorganic-organic magnetic nanocomposites using reactive chemistry often leads to a loss of super-paramagnetisim when conducted in the presence of iron oxide nanoparticles. We present here a low energy and chemically-mild process of co-nanoprecipitation using SPIONs and homopolymers or amphiphilic block copolymers, of varying architecture and hydrophilic/hydrophobic balance, which efficiently generates near monodisperse SPION-containing polymer nanoparticles with complete retention of magnetism, and highly reversible aggregation and redispersion behaviour. When linear and branched block copolymers with inherent water-solubility are used, a SPION-directed nanoprecipitation mechanism appears to dominate the nanoparticle formation presenting new opportunities for tailoring and scaling highly functional systems for a range of applications. Electronic supplementary information (ESI) available: Additional experimental details, NMR spectra, GPC chromatograms, kinetics experiments, graphs of nanopreciptate aggregation and cycling studies and SPION characterisation. See DOI: 10.1039/c6nr00788k

Global structure of forked DNA in solution revealed by high-resolution single-molecule FRET.

PubMed

Sabir, Tara; Schröder, Gunnar F; Toulmin, Anita; McGlynn, Peter; Magennis, Steven W

2011-02-09

Branched DNA structures play critical roles in DNA replication, repair, and recombination in addition to being key building blocks for DNA nanotechnology. Here we combine single-molecule multiparameter fluorescence detection and molecular dynamics simulations to give a general approach to global structure determination of branched DNA in solution. We reveal an open, planar structure of a forked DNA molecule with three duplex arms and demonstrate an ion-induced conformational change. This structure will serve as a benchmark for DNA-protein interaction studies.

Anatomical analysis of medial branches of dorsal rami of cervical nerves for radiofrequency thermocoagulation.

PubMed

Kweon, Tae Dong; Kim, Ji Young; Lee, Hye Yeon; Kim, Myung Hwa; Lee, Youn-Woo

2014-01-01

Cervical medial branch blocks are used to treat patients with chronic neck pain. The aim of this study was to clarify the anatomical aspects of the cervical medial branches to improve the accuracy and safety of radiofrequency denervation. Twenty cervical specimens were harvested from 20 adult cadavers. The anatomical parameters of the C4-C7 cervical medial branches were measured. The 3-dimensional computed tomography reconstruction images of the bone were also analyzed. Based on cadaveric analysis, most of the cervical dorsal rami gave off 1 medial branch; however, the cervical dorsal rami gave off 2 medial branches in 27%, 15%, 2%, and 0% at the vertebral level C4, C5, C6, and C7, respectively. The diameters of the medial branches varied from 1.0 to 1.2 mm, and the average distance from the notch of inferior articular process to the medial branches was about 2 mm. Most of the bifurcation sites were located at the medial side of the posterior tubercle of the transverse process. On the analysis of 3-dimensional computed tomography reconstruction images, cervical medial branches (C4 to C6) passed through the upper 49% to 53% of a line between the tips of 2 consecutive superior articular processes (anterior line). Also, cervical medial branches passed through the upper 28% to 35% of a line between the midpoints of 2 consecutive facet joints (midline). The present anatomical study may help improve accuracy and safety during radiofrequency denervation of the cervical medial branches.

Sub-Camera Calibration of a Penta-Camera

NASA Astrophysics Data System (ADS)

Jacobsen, K.; Gerke, M.

2016-03-01

Penta cameras consisting of a nadir and four inclined cameras are becoming more and more popular, having the advantage of imaging also facades in built up areas from four directions. Such system cameras require a boresight calibration of the geometric relation of the cameras to each other, but also a calibration of the sub-cameras. Based on data sets of the ISPRS/EuroSDR benchmark for multi platform photogrammetry the inner orientation of the used IGI Penta DigiCAM has been analyzed. The required image coordinates of the blocks Dortmund and Zeche Zollern have been determined by Pix4Dmapper and have been independently adjusted and analyzed by program system BLUH. With 4.1 million image points in 314 images respectively 3.9 million image points in 248 images a dense matching was provided by Pix4Dmapper. With up to 19 respectively 29 images per object point the images are well connected, nevertheless the high number of images per object point are concentrated to the block centres while the inclined images outside the block centre are satisfying but not very strongly connected. This leads to very high values for the Student test (T-test) of the finally used additional parameters or in other words, additional parameters are highly significant. The estimated radial symmetric distortion of the nadir sub-camera corresponds to the laboratory calibration of IGI, but there are still radial symmetric distortions also for the inclined cameras with a size exceeding 5μm even if mentioned as negligible based on the laboratory calibration. Radial and tangential effects of the image corners are limited but still available. Remarkable angular affine systematic image errors can be seen especially in the block Zeche Zollern. Such deformations are unusual for digital matrix cameras, but it can be caused by the correlation between inner and exterior orientation if only parallel flight lines are used. With exception of the angular affinity the systematic image errors for corresponding cameras of both blocks have the same trend, but as usual for block adjustments with self calibration, they still show significant differences. Based on the very high number of image points the remaining image residuals can be safely determined by overlaying and averaging the image residuals corresponding to their image coordinates. The size of the systematic image errors, not covered by the used additional parameters, is in the range of a square mean of 0.1 pixels corresponding to 0.6μm. They are not the same for both blocks, but show some similarities for corresponding cameras. In general the bundle block adjustment with a satisfying set of additional parameters, checked by remaining systematic errors, is required for use of the whole geometric potential of the penta camera. Especially for object points on facades, often only in two images and taken with a limited base length, the correct handling of systematic image errors is important. At least in the analyzed data sets the self calibration of sub-cameras by bundle block adjustment suffers from the correlation of the inner to the exterior calibration due to missing crossing flight directions. As usual, the systematic image errors differ from block to block even without the influence of the correlation to the exterior orientation.

The Notch ligand Delta-like 4 negatively regulates endothelial tip cell formation and vessel branching

PubMed Central

Suchting, Steven; Freitas, Catarina; le Noble, Ferdinand; Benedito, Rui; Bréant, Christiane; Duarte, Antonio; Eichmann, Anne

2007-01-01

Delta-like 4 (Dll4) is a transmembrane ligand for Notch receptors that is expressed in arterial blood vessels and sprouting endothelial cells. Here we show that Dll4 regulates vessel branching during development by inhibiting endothelial tip cell formation. Heterozygous deletion of dll4 or pharmacological inhibition of Notch signaling using γ-secretase inhibitor revealed a striking vascular phenotype, with greatly increased numbers of filopodia-extending endothelial tip cells and increased expression of tip cell marker genes compared with controls. Filopodia extension in dll4+/− retinal vessels required the vascular growth factor VEGF and was inhibited when VEGF signaling was blocked. Although VEGF expression was not significantly altered in dll4+/− retinas, dll4+/− vessels showed increased expression of VEGF receptor 2 and decreased expression of VEGF receptor 1 compared with wild-type, suggesting they could be more responsive to VEGF stimulation. In addition, expression of dll4 in wild-type tip cells was itself decreased when VEGF signaling was blocked, indicating that dll4 may act downstream of VEGF as a “brake” on VEGF-mediated angiogenic sprouting. Taken together, these data reveal Dll4 as a negative regulator of vascular sprouting and vessel branching that is required for normal vascular network formation during development. PMID:17296941

The Notch ligand Delta-like 4 negatively regulates endothelial tip cell formation and vessel branching.

PubMed

Suchting, Steven; Freitas, Catarina; le Noble, Ferdinand; Benedito, Rui; Bréant, Christiane; Duarte, Antonio; Eichmann, Anne

2007-02-27

Delta-like 4 (Dll4) is a transmembrane ligand for Notch receptors that is expressed in arterial blood vessels and sprouting endothelial cells. Here we show that Dll4 regulates vessel branching during development by inhibiting endothelial tip cell formation. Heterozygous deletion of dll4 or pharmacological inhibition of Notch signaling using gamma-secretase inhibitor revealed a striking vascular phenotype, with greatly increased numbers of filopodia-extending endothelial tip cells and increased expression of tip cell marker genes compared with controls. Filopodia extension in dll4(+/-) retinal vessels required the vascular growth factor VEGF and was inhibited when VEGF signaling was blocked. Although VEGF expression was not significantly altered in dll4(+/-) retinas, dll4(+/-) vessels showed increased expression of VEGF receptor 2 and decreased expression of VEGF receptor 1 compared with wild-type, suggesting they could be more responsive to VEGF stimulation. In addition, expression of dll4 in wild-type tip cells was itself decreased when VEGF signaling was blocked, indicating that dll4 may act downstream of VEGF as a "brake" on VEGF-mediated angiogenic sprouting. Taken together, these data reveal Dll4 as a negative regulator of vascular sprouting and vessel branching that is required for normal vascular network formation during development.

The impact of lignin source on its self-assembly in solution

DOE PAGES

Ratnaweera, Dilru R.; Saha, Dipendu; Pingali, Sai Venkatesh; ...

2015-07-30

Recently, there has been a growing interest in developing value added uses for lignin, including the utilization of lignins as a precursor for carbon materials. Proper understanding of the association behavior of lignins during solution processing provides important structural information that is needed to rationally optimize the use of lignins in industry in a range of value added applications. In this paper, we follow the assembly of lignin molecules from a variety of sources in dimethyl sulfoxide, a good solvent for lignins, using small angle neutron scattering. In order to mimic industrial processing conditions, concentrations of lignins were kept abovemore » the overlap concentration. At small length scales, short lignin segments with ~4–10 monolignol units associate to form rigid rod-like/cylindrical building blocks, where the number of repeat units in a cylindrical segment decreases with increasing lignin concentration. These cylindrical building blocks associate to form aggregates with low cross-linking densities and a random coil or network like structures from highly branched lignin structures. The degree of branching of the base lignin molecule, which varies with source, plays a crucial role in determining their association behavior. Finally, the overall sizes of the aggregates decrease with increasing concentration at low cross-linking densities, whereas the opposite trend is observed for highly branched lignins.« less

Calbindin and parvalbumin are early markers of non-mitotically regenerating hair cells in the bullfrog vestibular otolith organs

NASA Technical Reports Server (NTRS)

Steyger, P. S.; Burton, M.; Hawkins, J. R.; Schuff, N. R.; Baird, R. A.

1997-01-01

Earlier studies have demonstrated hair cell regeneration in the absence of cell proliferation, and suggested that supporting cells could phenotypically convert into hair cells following hair cell loss. Because calcium-binding proteins are involved in gene up-regulation, cell growth, and cell differentiation, we wished to determine if these proteins were up-regulated in scar formations and regenerating hair cells following gentamicin treatment. Calbindin and parvalbumin immunolabeling was examined in control or gentamicin-treated (GT) bullfrog saccular and utricular explants cultured for 3 days in amphibian culture medium or amphibian culture medium supplemented with aphidicolin, a blocker of nuclear DNA replication in eukaryotic cells. In control cultures, calbindin and parvalbumin immunolabeled the hair bundles and, less intensely, the cell bodies of mature hair cells. In GT or mitotically-blocked GT (MBGT) cultures, calbindin and parvalbumin immunolabeling was also seen in the hair bundles, cuticular plates, and cell bodies of hair cells with immature hair bundles. Thus, these antigens were useful markers for both normal and regenerating hair cells. Supporting cell immunolabeling was not seen in control cultures nor in the majority of supporting cells in GT cultures. In MBGT cultures, calbindin and parvalbumin immunolabeling was up-regulated in the cytosol of single supporting cells participating in scar formations and in supporting cells with hair cell-like characteristics. These data provide further evidence that non-mitotic hair cell regeneration in cultures can be accomplished by the conversion of supporting cells into hair cells.

A novel mechanism of bradycardia and the character of acetylcholine in the heart.

PubMed

Młynarska, M S; Garlicki, M; Jakobczak, M M; Skowron-Cendrzak, A

2006-01-01

At first the aim of our study was to observe the simultaneous responses of two hearts after intraarterial (into a. femoralis) adrenaline administration, in the rat with its own heart and a transplanted one--hence non-innervated. After these, some next experiments were performed: in some rats the His bundle of the heterotopically transplanted heart was damaged before transplantation. In all experiments the heart rate was observed on ECG and simultaneously, the arterial blood pressure was recorded from femoral artery in Vetbutal-anaesthetized rats. 1) both the heterotopically transplanted, non-innervated heart and the animal's own heart reacted to adrenaline administeration by producing bradycardia, 2) the heterotopically transplanted heart with the damaged His bundle--hence with a ventricular block reacted to adrenaline administration by raising the heart rate, whereas at the same time and in the same animal its own heart reacted by producing bradycardia. 1) the cause of bradycardia after adrenaline administration does not lie in the reflex from the arcus aortae, since we observed bradycardia after adrenaline administration also in the transplanted, non-innervated heart; therefore the baroreceptor reflex is not the cause of bradycardia after adrenaline administration; 2) bradycardia after adrenaline occurs in both the proper heart and the transplanted, non-innervated one, as a result of an interaction between two cholinergic centres which must be situated above and below the point of the His bundle interruption. The role of acetylcholine in the heart results from the interaction between these two centres.

78 FR 13761 - Designation of One Entity Pursuant to Executive Order 13448

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-28

... branches, of the persons listed in the Annex to E.O. 13448, as well as those persons determined by the..., Burma; No. 1 Ywama Curve, Ba Yint Naung Road, Block (2), Hlaing Township, Yangon, Burma; SWIFT/BIC AYAB...

Articulated Bone Block for Posterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Autograft: Surgical Technique to Facilitate Graft Passage.

PubMed

Cugat, Ramón; Alentorn-Geli, Eduard; Cuscó, Xavier; Navarro, Jordi; Steinbacher, Gilbert; Álvarez-Díaz, Pedro; Seijas, Roberto; Barastegui, David; García-Balletbó, Montse

2018-02-01

Posterior cruciate ligament reconstruction using the transtibial technique provides successful clinical outcomes. However, a bone-patellar tendon-bone (BTB) autograft with the transtibial technique has not been used by some surgeons because of concerns with graft passage from the tibial to the femoral tunnels (sharp turn) that can damage graft fibers. In the present surgical technique, an arthroscopic, transtibial, single-bundle technique for posterior cruciate ligament reconstruction using the BTB autograft with an easy and effective technical tip to facilitate graft passage is presented. Once the BTB is harvested, the femoral bone block is divided into 2 equal-sized blocks providing an articulated structure while preserving the tendon component. This facilitates the passage of the BTB tendon once it is entered in the posterior tibia and the graft has to make a sharp turn to reach the femoral tunnel. This easy and effective technique tip may avoid graft damage during the sharp turn, while maintaining all the advantages of a BTB autograft (bone-to-bone healing, own tissue with fast incorporation, and strong fixation and stability).

Mechanosensilla in the adult abdomen of Drosophila: engrailed and slit help to corral the peripheral sensory axons into segmental bundles.

PubMed

Fabre, Caroline C G; Casal, José; Lawrence, Peter A

2010-09-01

The abdomen of adult Drosophila bears mechanosensory bristles with axons that connect directly to the CNS, each hemisegment contributing a separate nerve bundle. Here, we alter the amount of Engrailed protein and manipulate the Hedgehog signalling pathway in clones of cells to study their effects on nerve pathfinding within the peripheral nervous system. We find that high levels of Engrailed make the epidermal cells inhospitable to bristle neurons; sensory axons that are too near these cells are either deflected or fail to extend properly or at all. We then searched for the engrailed-dependent agent responsible for these repellent properties. We found slit to be expressed in the P compartment and, using genetic mosaics, present evidence that Slit is the responsible molecule. Blocking the activity of the three Robo genes (putative receptors for Slit) with RNAi supported this hypothesis. We conclude that, during normal development, gradients of Slit protein repel axons away from compartment boundaries - in consequence, the bristles from each segment send their nerves to the CNS in separated sets.

Bioinspired M-13 bacteriophage-based photonic nose for differential cell recognition† †Electronic supplementary information (ESI) available: Instrumentation, diagrams, protein sequences and additional results. See DOI: 10.1039/c6sc02021f Click here for additional data file.

PubMed Central

Moon, Jong-Sik; Kim, Won-Geun; Shin, Dong-Myeong; Lee, So-Young; Kim, Chuntae; Lee, Yujin; Han, Jiye; Kim, Kyujung

2017-01-01

A bioinspired M-13 bacteriophage-based photonic nose was developed for differential cell recognition. The M-13 bacteriophage-based photonic nose exhibits characteristic color patterns when phage bundle nanostructures, which were genetically modified to selectively capture vapor phase molecules, are structurally deformed. We characterized the color patterns of the phage bundle nanostructure in response to cell proliferation via several biomarkers differentially produced by cells, including hydrazine, o-xylene, ethylbenzene, ethanol and toluene. A specific color enables the successful identification of different types of molecular and cellular species. Our sensing technique utilized the versatile M-13 bacteriophage as a building block for fabricating bioinspired photonic crystals, which enables ease of fabrication and tunable selectivity through genetic engineering. Our simple and versatile bioinspired photonic nose could have possible applications in sensors for human health and national security, food discrimination, environmental monitoring, and portable and wearable sensors. PMID:28572902

Low Night Temperature Affects the Phloem Ultrastructure of Lateral Branches and Raffinose Family Oligosaccharide (RFO) Accumulation in RFO-Transporting Plant Melon (Cucumismelo L.) during Fruit Expansion

PubMed Central

Hao, Jinghong; Gu, Fengying; Zhu, Jie; Lu, Shaowei; Liu, Yifei; Li, Yunfei; Chen, Weizhi; Wang, Liping; Fan, Shuangxi; Xian, Cory J.

2016-01-01

Due to the importance and complexity of photo assimilate transport in raffinose family oligosaccharide (RFO)-transporting plants such as melon, it is important to study the features of the transport structure (phloem) particularly of the lateral branches connecting the source leaves and the sink fruits, and its responses to environmental challenges. Currently, it is unclear to what extents the cold environmental temperature stress would alter the phloem ultrastructure and RFO accumulation in RFO-transporting plants. In this study, we firstly utilized electron microscopy to investigate the changes in the phloem ultrastructure of lateral branches and RFO accumulation in melons after being subjected to low night temperatures (12°C and 9°C). The results demonstrated that exposure to 9°C and 12°C altered the ultrastructure of the phloem, with the effect of 9°C being more obvious. The most obvious change was the appearance of plasma membrane invaginations in 99% companion cells and intermediary cells. In addition, phloem parenchyma cells contained chloroplasts with increased amounts of starch grains, sparse cytoplasm and reduced numbers of mitochondria. In the intermediary cells, the volume of cytoplasm was reduced by 50%, and the central vacuole was present. Moreover, the treatment at 9°C during the night led to RFO accumulation in the vascular bundles of the lateral branches and fruit carpopodiums. These ultrastructural changes of the transport structure (phloem) following the treatment at 9°C represented adaptive responses of melons to low temperature stresses. Future studies are required to examine whether these responses may affect phloem transport. PMID:27501301

Low Night Temperature Affects the Phloem Ultrastructure of Lateral Branches and Raffinose Family Oligosaccharide (RFO) Accumulation in RFO-Transporting Plant Melon (Cucumismelo L.) during Fruit Expansion.

PubMed

Hao, Jinghong; Gu, Fengying; Zhu, Jie; Lu, Shaowei; Liu, Yifei; Li, Yunfei; Chen, Weizhi; Wang, Liping; Fan, Shuangxi; Xian, Cory J

2016-01-01

Due to the importance and complexity of photo assimilate transport in raffinose family oligosaccharide (RFO)-transporting plants such as melon, it is important to study the features of the transport structure (phloem) particularly of the lateral branches connecting the source leaves and the sink fruits, and its responses to environmental challenges. Currently, it is unclear to what extents the cold environmental temperature stress would alter the phloem ultrastructure and RFO accumulation in RFO-transporting plants. In this study, we firstly utilized electron microscopy to investigate the changes in the phloem ultrastructure of lateral branches and RFO accumulation in melons after being subjected to low night temperatures (12°C and 9°C). The results demonstrated that exposure to 9°C and 12°C altered the ultrastructure of the phloem, with the effect of 9°C being more obvious. The most obvious change was the appearance of plasma membrane invaginations in 99% companion cells and intermediary cells. In addition, phloem parenchyma cells contained chloroplasts with increased amounts of starch grains, sparse cytoplasm and reduced numbers of mitochondria. In the intermediary cells, the volume of cytoplasm was reduced by 50%, and the central vacuole was present. Moreover, the treatment at 9°C during the night led to RFO accumulation in the vascular bundles of the lateral branches and fruit carpopodiums. These ultrastructural changes of the transport structure (phloem) following the treatment at 9°C represented adaptive responses of melons to low temperature stresses. Future studies are required to examine whether these responses may affect phloem transport.

Structure and Evolution of Insect Sperm: New Interpretations in the Age of Phylogenomics.

PubMed

Dallai, Romano; Gottardo, Marco; Beutel, Rolf Georg

2016-01-01

This comprehensive review of the structure of sperm in all orders of insects evaluates phylogenetic implications, with the background of a phylogeny based on transcriptomes. Sperm characters strongly support several major branches of the phylogeny of insects-for instance, Cercophora, Dicondylia, and Psocodea-and also different infraordinal groups. Some closely related taxa, such as Trichoptera and Lepidoptera (Amphiesmenoptera), differ greatly in sperm structure. Sperm characters are very conservative in some groups (Heteroptera, Odonata) but highly variable in others, including Zoraptera, a small and morphologically uniform group with a tremendously accelerated rate of sperm evolution. Unusual patterns such as sperm dimorphism, the formation of bundles, or aflagellate and immotile sperm have evolved independently in several groups.

Method and device for tensile testing of cable bundles

DOEpatents

Robertson, Lawrence M; Ardelean, Emil V; Goodding, James C; Babuska, Vit

2012-10-16

A standard tensile test device is improved to accurately measure the mechanical properties of stranded cables, ropes, and other composite structures wherein a witness is attached to the top and bottom mounting blocks holding the cable under test. The witness is comprised of two parts: a top and a bottom rod of similar diameter with the bottom rod having a smaller diameter stem on its upper end and the top rod having a hollow opening in its lower end into which the stem fits forming a witness joint. A small gap is present between the top rod and the larger diameter portion of the bottom rod. A standard extensometer is attached to the top and bottom rods of the witness spanning this small witness gap. When a force is applied to separate the mounting blocks, the gap in the witness expands the same length that the entire test specimen is stretched.

Electrocardiographic findings in chronic hemodialysis patients.

PubMed

Bignotto, Luís Henrique; Kallás, Marina Esteves; Djouki, Rafael Jorge Teixeira; Sassaki, Marcela Mayume; Voss, Guilherme Ota; Soto, Cristina Lopez; Frattini, Fernando; Medeiros, Flávia Silva Reis

2012-01-01

Cardiovascular disease is the leading cause of mortality among patients on dialysis. When considering all causes of death, about 30% are classified as cardiac arrest, death of unknown cause or cardiac arrhythmia. The increasing time of ventricular depolarization and repolarization, measured non-invasively by measuring the QT interval on the electrocardiogram at rest, has emerged as a predictor of complex ventricular arrhythmias, a major cause of sudden cardiac death. To determine the electrocardiographic alterations present in hemodialysis (HD) patients, measuring the QT interval and its relationship with clinical and laboratory variables. Patients above 18 years on dialysis were approached to participate in the study and, after consent, were submitted to the examination of 12-lead electrocardiogram. Clinical data were reviewed to assess the presence of comorbidities, as well as anthropometric and blood pressure measures. Blood samples were collected to determinate hemoglobin and serum levels of calcium, phosphorus and potassium. One hundred and seventy nine patients were included in the study. The majority of the patients were male (64.8%) and white (54.7%); the average age was 58.5 ± 14.7 years old. About 50% of all patients had, at least, one electrical conduction disturb. About 50% of all patients had QTc prolongation and experienced a significant increase in the frequency of Left Ventricular Hypertrophy (LVH), changes of the cardiac rhythm and bundle branch blocks, and a lower body mass index (BMI), when compared with normal QTc interval patients. Patients with chronic kidney disease (CKD) on hemodialysis had high frequency of abnormal electrocardiographic findings, including a high prevalence of patients with prolonged QTc interval. This study also found a significant association between prolonged QTc interval and the presence of Diabetes and lower values of BMI.

Anomalous origin of coronary arteries from the "wrong" sinus in athletes: Diagnosis and management strategies.

PubMed

Palmieri, Vincenzo; Gervasi, Salvatore; Bianco, Massimiliano; Cogliani, Roberta; Poscolieri, Barbara; Cuccaro, Francesco; Marano, Riccardo; Mazzari, Mario; Basso, Cristina; Zeppilli, Paolo

2018-02-01

Although anomalous origin of left (AOLCA) and right coronary artery (AORCA) from the wrong sinus may cause sudden death (SD) in athletes, early diagnosis and management of these anomalies are still challenging. We analysed clinical/instrumental profiles of athletes identified with AOLCA/AORCA focusing our attention on diagnosis, management and follow-up. We report 23 athletes (17 males, mean age 27±17yrs.), 6 with AOLCA and 17 with AORCA. Diagnosis was made by trans-thoracic echocardiography (TTE) in 21/23(91%). Symptoms were present only in 10(41%). Only 3 had an abnormal rest-ECG and 9(39%) an abnormal stress test ECG (3 ST-depression, 4 ventricular arrhythmias, 1 supraventricular arrhythmias, 1 rate-dependent left-bundle-branch-block). Anatomy of the anomalous coronary artery showed no significant correlation with clinical presentation, except for a tendency to higher occurrence of proximal hypoplasia in symptomatic athletes (83% vs 40%, p=0.09). All athletes were disqualified from competitive-sports and advised to avoid strenuous effort. Surgery was recommended to all athletes with AOLCA and 6 with AORCA, but only 6 underwent surgery. No major cardiac events or ischemic symptoms/signs occurred during a mean follow-up of 65±70months. Early diagnosis of AOLCA/AORCA in athletes is feasible by TTE. Typical symptoms/signs of myocardial ischemia are present only in one third of cases thus underlying the need of a high index of clinical suspicion to achieve the diagnosis. After exercise restriction, none had major cardiac events or ischemia symptoms/signs recurrence. There was no correlation between anatomical characteristics and clinical presentation with the possible exception of coronary hypoplasia. Copyright © 2017 Elsevier B.V. All rights reserved.

Subcutaneous Implantable Cardioverter Defibrillator in Patients With Hypertrophic Cardiomyopathy: An Initial Experience.

PubMed

Weinstock, Jonathan; Bader, Yousef H; Maron, Martin S; Rowin, Ethan J; Link, Mark S

2016-02-12

The subcutaneous implantable cardioverter defibrillator (S-ICD) has been developed to avert risks associated with transvenous defibrillator leads. The technology is attractive for younger patients, such as those with hypertrophic cardiomyopathy (HCM). However, there are limited data on S-ICD use in HCM. HCM patients identified at risk for sudden death were considered for S-ICD implantation. Patients were screened for potential oversensing by surface electrocardiography (ECG). At implant, defibrillation threshold (DFT) testing was performed at 65, 50, and 35 joules (J). Twenty-seven patients were considered for S-ICD implantation, and after screening, 23 (85%) remained eligible. The presence of a bundle branch block was associated with screening failure, whereas elevated body mass index (BMI) showed a trend toward association. One patient passed screening at rest, but failed with an ECG obtained after exercise. At implant, the S-ICD terminated ventricular fibrillation (VF) with a 65J shock in all 15 implanted patients and a 50J shock was successful in 12 of 15. A 35J shock terminated VF in 10 of 12 patients. DFT failure at 50 J was associated with a higher BMI. There were no appropriate shocks after a median follow-up of 17.5 (3-35) months, and 1 patient received an inappropriate shock attributable to a temporary reduction in QRS amplitude while bending forward, resulting in oversensing, despite successful screening. In a high-risk HCM cohort without a pacing indication referred for consideration of an ICD, the majority were eligible for S-ICD. The S-ICD is effective at recognizing and terminating VF at implant with a wide safety margin. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Amisulpride overdose is frequently associated with QT prolongation and torsades de pointes.

PubMed

Isbister, Geoffrey K; Balit, Corrine R; Macleod, Dawson; Duffull, Stephen B

2010-08-01

This study aimed to describe the effects of the antipsychotic amisulpride in overdose, including the frequency of QT prolongation and torsades de pointes. Cases of amisulpride overdose (>1 g) were recruited from 2 state poison centers and a tertiary toxicology unit over 5 years. A 1-page clinical research form was used to collect clinical information. Copies of all electrocardiograms were obtained. Electrocardiogram parameters (QRS and QT intervals) were manually measured as previously described, and plots of QT-heart rate (HR) pairs were compared with the QT nomogram. There were 83 patients with amisulpride overdoses with a median age of 29 years (interquartile range [IQR], 23-40 years), and 42 (51%) were female. The median dose ingested was 6 g (IQR, 3-13 g, range, 1.2-120 g). The median HR was 66 beats/min (IQR, 60-81 beats/min). Bradycardia occurred in 20 cases (24%), and hypotension in 19 (23%). From 440 electrocardiograms (average of 5 per case; range, 1-15), an abnormal QT-HR pair occurred in 61 cases (73%). Torsades de pointes developed in 6 cases (7%), with doses of 4, 4.6, 18, 24, 32, and 80 g. The patient taking 32 g died after a cardiac arrest. Widened QRS did not occur except transient rate-dependent bundle-branch block in 3 cases. There were significant associations of bradycardia, hypokalemia, and hypocalcaemia, with QT prolongation and torsades de pointes. Central nervous system effects were uncommon with coma in 7 cases, seizures in 2, and dystonic reactions in 2. Amisulpride overdose commonly causes QT prolongation, bradycardia, and hypotension. Torsades de pointes occurred commonly enough to suggest that amisulpride is highly cardiotoxic in overdose.

Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images.

PubMed

Zweerink, Alwin; Allaart, Cornelis P; Kuijer, Joost P A; Wu, LiNa; Beek, Aernout M; van de Ven, Peter M; Meine, Mathias; Croisille, Pierre; Clarysse, Patrick; van Rossum, Albert C; Nijveldt, Robin

2017-12-01

Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. • Myocardial strain analysis could potentially improve patient selection for CRT. • Currently a well validated clinical approach to derive segmental strains is lacking. • The novel SLICE technique derives segmental strains from standard CMR cine images. • SLICE-derived strain markers of CRT response showed close agreement with CMR-TAG. • Future studies will focus on the prognostic value of SLICE in CRT candidates.

[Thrombocytopenia induced by type II heparin and myocardial infarct: 2 case reports].

PubMed

Antonijević, Nabojsa; Stanojević, Milica; Perunicić, Jovan; Djokić, Milan; Miković, Danijla; Kovac, Mirjana; Miljić, Predrag; Milosević, Rajko; Terzić, Branka; Vasiljević, Zorana

2004-01-01

Heparin-induced thrombocytopenia (HIT) type II is an acquired thrombophylic state and life-threatening immune complication of a heparin treatment mainly clinically manifested by marked thrombocytopenia, frequently by arterial and venous thrombosis, and sometimes by skin changes. Functional assay as heparin aggregation test and 14C-serotonin release assays are used in diagnostics as well as antigen assays of which detection tests for heparin-platelet factor 4 antibodies are most frequently used. Considering the fact that there is no single reliable assays for HIT II detection available, sometimes it is necessary to combine both of the above-mentioned types of assays. We present the case of a 57-year-old patient with an acute anterior myocardial infarction with cardiac insufficiency of III and IV degree according to Killip, recurrent ventricular fibrillation and diabetes mellitus type II developing thrombocytopenia to 37 x 10(9)/l accompanied with typical skin changes. The diagnosis was confirmed by the heparin aggregation test. The second patient aged 70 undergoing the treatment for anteroseptal myocardial infarction and reinfarction of the inferior wall complicated by a cardiogenic shock and acute right bundle branch block developed thrombocytopenia 59 x 10(9)/l on the third day of the heparin therapy, with the remark that he had received a heparin therapy during the first infarction as well. Antibodies against heparin-platelet factor 4 were detected by particle gel ID-HPF4 immuno-assay. In both patients, the disease had a lethal outcome despite all then available therapeutic measures applied. Further on we discuss advantages of certain types of tests, a therapy doctrine, need for urgent therapeutic measures, inclusive of the administration of antithrombins, avoidance of harmful procedures like low-molecular-weight heparins administration and prophylactic platelet transfusion as well as preventive measures.

Distinctive Left Ventricular Activations Associated With ECG Pattern in Heart Failure Patients.

PubMed

Derval, Nicolas; Duchateau, Josselin; Mahida, Saagar; Eschalier, Romain; Sacher, Frederic; Lumens, Joost; Cochet, Hubert; Denis, Arnaud; Pillois, Xavier; Yamashita, Seigo; Komatsu, Yuki; Ploux, Sylvain; Amraoui, Sana; Zemmoura, Adlane; Ritter, Philippe; Hocini, Mélèze; Haissaguerre, Michel; Jaïs, Pierre; Bordachar, Pierre

2017-06-01

In contrast to patients with left bundle branch block (LBBB), heart failure patients with narrow QRS and nonspecific intraventricular conduction delay (NICD) display a relatively limited response to cardiac resynchronization therapy. We sought to compare left ventricular (LV) activation patterns in heart failure patients with narrow QRS and NICD to patients with LBBB using high-density electroanatomic activation maps. Fifty-two heart failure patients (narrow QRS [n=18], LBBB [n=11], NICD [n=23]) underwent 3-dimensional electroanatomic mapping with a high density of mapping points (387±349 LV). Adjunctive scar imaging was available in 37 (71%) patients and was analyzed in relation to activation maps. LBBB patients typically demonstrated (1) a single LV breakthrough at the septum (38±15 ms post-QRS onset); (2) prolonged right-to-left transseptal activation with absence of direct LV Purkinje activity; (3) homogeneous propagation within the LV cavity; and (4) latest activation at the basal lateral LV. In comparison, both NICD and narrow QRS patients demonstrated (1) multiple LV breakthroughs along the posterior or anterior fascicles: narrow QRS versus LBBB, 5±2 versus 1±1; P =0.0004; NICD versus LBBB, 4±2 versus 1±1; P =0.001); (2) evidence of early/pre-QRS LV electrograms with Purkinje potentials; (3) rapid propagation in narrow QRS patients and more heterogeneous propagation in NICD patients; and (4) presence of limited areas of late activation associated with LV scar with high interindividual heterogeneity. In contrast to LBBB patients, narrow QRS and NICD patients are characterized by distinct mechanisms of LV activation, which may predict poor response to cardiac resynchronization therapy. © 2017 American Heart Association, Inc.

Late deterioration of left ventricular function after right ventricular pacemaker implantation.

PubMed

Bellmann, Barbara; Muntean, Bogdan G; Lin, Tina; Gemein, Christopher; Schmitz, Kathrin; Schauerte, Patrick

2016-09-01

Right ventricular (RV) pacing induces a left bundle branch block pattern on ECG and may promote heart failure. Patients with dual chamber pacemakers (DCPs) who present with progressive reduction in left ventricular ejection fraction (LVEF) secondary to RV pacing are candidates for cardiac resynchronization therapy (CRT). This study analyzes whether upgrading DCP to CRT with the additional implantation of a left ventricular (LV) lead improves LV function in patients with reduced LVEF following DCP implantation. Twenty-two patients (13 males) implanted with DCPs and a high RV pacing percentage (>90%) were evaluated in term of new-onset heart failure symptoms. The patients were enrolled in this retrospective single-center study after obvious causes for a reduced LVEF were excluded with echocardiography and coronary angiography. In all patients, DCPs were then upgraded to biventricular devices. LVEF was analyzed with a two-sided t-test. QRS duration and brain natriuretic peptide (BNP) levels were analyzed with the unpaired t-test. LVEF declined after DCP implantation from 54±10% to 31±7%, and the mean QRS duration was 161±20 ms during RV pacing. NT-pro BNP levels were elevated (3365±11436 pmol/L). After upgrading to a biventricular device, a biventricular pacing percentage of 98.1±2% was achieved. QRS duration decreased to 108±16 ms and 106±20 ms after 1 and 6 months, respectively. There was a significant increase in LVEF to 38±8% and 41±11% and a decrease in NT-pro BNP levels to 3088±2326 pmol/L and 1860±1838 pmol/L at 1 and 6 months, respectively. Upgrading to CRT may be beneficial in patients with DCPs and heart failure induced by a high RV pacing percentage.

The clinical benefit of cardiac resynchronization therapy optimization using a device-based hemodynamic sensor in a patient with dilated cardiomyopathy: a case report.

PubMed

Volpicelli, Mario; Covino, Gregorio; Capogrosso, Paolo

2015-12-19

Results on the evolution of the clinical status of patients undergoing cardiac resynchronization therapy with a defibrillator after automatic optimization of their cardiac resynchronization therapy are scarce. We observed a rapid and important change in the clinical status of our non-responding patient following activation of a sensor capable of weekly atrioventricular and interventricular delays' optimization. A 78-year-old Caucasian man presented with dilated cardiomyopathy, left bundle branch block, a left ventricular ejection fraction of 35 %, New York Heart Association class III/IV heart failure, and paroxysmal atrial fibrillation. Our patient was implanted with a cardiac resynchronization device with a defibrillator and the SonRtip atrial lead. Right ventricular and left ventricular leads were also implanted. Because of the recurrence of atrial fibrillation, the automatic optimization was set off at discharge. Consequently, the device did not optimize atrioventricular and interventricular delays (programming at discharge: 125 ms for the atrioventricular delay and 0 ms for the interventriculardelay). Our patient was treated with an anti-arrhythmic drug. Five months after implantation, his clinical status remained impaired (left ventricular ejection fraction = 30 %). The SonR signal amplitude had also decreased from 0.52 g to 0.29 g. Nevertheless, because our patient was no longer presenting with atrial fibrillation, the anti-arrhythmic treatment was stopped and the SonR optimization system was activated. After 2 months of automatic cardiac resynchronization therapy with defibrillator optimization, our patient's clinical status had significantly improved (left ventricular ejection fraction = 60 %, New York Heart Association class II) and the SonR signal amplitude had doubled shortly after the first weekly automatic optimization. In this non-responding patient, device-based automatic cardiac resynchronization therapy optimization was shown to significantly improve his clinical status.

Functional response to cardiac resynchronization therapy is associated with improved clinical outcome and absence of appropriate shocks.

PubMed

Van Boven, Nick; Bogaard, Kjell; Ruiter, Jaap; Kimman, Geert; Theuns, Dominic; Kardys, Isabella; Umans, Victor

2013-03-01

We evaluated clinical outcome and incidence of (in)appropriate shocks in consecutive chronic heart failure (CHF) patients treated with CRT with a defibrillator (CRT-D) according to functional response status. Furthermore, we investigated which factors predict such functional response. In a large teaching hospital, 179 consecutive CHF patients received CRT-D in 2005-2010. Patients were considered functional responders if left ventricular ejection fraction (LVEF) increased to ≥ 35% postimplantation. Analysis was performed on 142 patients, who had CRT-D as primary prevention, complete data and a baseline LVEF <35%. Endpoints consisted of all-cause mortality, heart failure (HF) hospitalizations, appropriate shocks and inappropriate shocks. Median follow-up was 3.0 years (interquartile range [IQR] 1.6-4.4) and median baseline LVEF was 20% (IQR 18-25%). The functional response-group consisted of 42 patients. In this group no patients died, none were hospitalized for HF, none received appropriate shocks and 3 patients (7.1%) received ≥ 1 inappropriate shocks. In comparison, the functional nonresponse group consisted of 100 patients, of whom 22 (22%) died (P = 0.003), 17 (17%) were hospitalized for HF (P = 0.007), 17 (17%) had ≥ 1 appropriate shocks (P = 0.003) and 8 (8.1%) received ≥ 1 inappropriate shocks (P = 0.78). Multivariable analysis showed that left bundle branch block (LBBB), QRS duration ≥ 150 milliseconds and no need for diuretics at baseline are independent predictors of functional response. Functional responders to CRT have a good prognosis and rarely need ICD therapy. LBBB, QRS duration ≥ 150 milliseconds and lack of chronic diuretic use predict functional response. © 2012 Wiley Periodicals, Inc.

Mortality in patients with TIMI 3 flow after PCI in relation to time delay to reperfusion.

PubMed

Vichova, Teodora; Maly, Marek; Ulman, Jaroslav; Motovska, Zuzana

2016-03-01

Percutaneous coronary intervention (PCI) performed within 12 h from symptom onset enables complete blood flow restoration in infarct-related artery in 90% of patients. Nevertheless, even with complete restoration of epicardial blood flow in culprit vessel (postprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade 3), myocardial perfusion at tissue level may be insufficient. We hypothesized that the outcome of patients with STEMI/bundle branch block (BBB)-myocardial infarction and post-PCI TIMI 3 flow is related to the time to reperfusion. Observational study based on a retrospective analysis of population of 635 consecutive patients with STEMI/BBB-MI and post-PCI TIMI 3 flow from January 2009 to December 2011 (mean age 63 years, 69.6% males). Mortality of patients was evaluated in relation to the time from symptom onset to reperfusion. A total of 83 patients (13.07%) with postprocedural TIMI 3 flow after PCI had died at 1-year follow-up. Median TD in patients who survived was 3.92 h (iqr 5.43), in patients who died 6.0 h (iqr 11.42), P = 0.004. Multiple logistic regression analysis identified time delay ≥ 9 h as significantly related to 1-year mortality of patients with STEMI/BBB-MI and post-PCI TIMI 3 flow (OR 1.958, P = 0.026). Other significant variables associated with mortality in multivariate regression analysis were: left ventricle ejection fraction < 30% (P = 0.006), age > 65 years (P < 0.001), Killip class >2 (P <0.001), female gender (P = 0.019), and creatinine clearance < 30 mL/min (P < 0.001). Time delay to reperfusion is significantly related to 1-year mortality of patients with STEMI/BBB-MI and complete restoration of epicardial blood flow in culprit vessel after PCI.

Malignant ventricular arrhythmias in alcoholic cardiomyopathy.

PubMed

Guzzo-Merello, Gonzalo; Dominguez, Fernando; González-López, Esther; Cobo-Marcos, Marta; Gomez-Bueno, Manuel; Fernandez-Lozano, Ignacio; Millan, Isabel; Segovia, Javier; Alonso-Pulpon, Luis; Garcia-Pavia, Pablo

2015-11-15

Excessive alcohol consumption is a well-known aetiology of atrial arrhythmias but there is little information concerning the prevalence or incidence of malignant ventricular arrhythmias in alcoholic cardiomyopathy (ACM). This study sought to investigate incidence and predictive factors of ventricular arrhythmias in ACM. Retrospective observational study of the clinical characteristics and long-term arrhythmic events in 282 consecutive patients with ACM (94 individuals) and idiopathic dilated cardiomyopathy (IDCM) (188 individuals) evaluated between 1993 and 2011. During a median follow-up of 38months (IQR:12-77), 42 patients died and 79 underwent heart transplantation [31 (33%) with ACM vs 90 (48%) with IDCM; p=0.017]. A total of 37 (13%) patients [18 (19%) ACM vs 20 (11%) IDCM; p=0.048] suffered malignant ventricular arrhythmias. On multivariate analysis, left bundle branch block (LBBB) (OR 2.4; CI95%: 1.2-5; p=0.015) and alcoholic aetiology (OR 2.3; CI95%: 1.1-4.5; p=0.026) were the only independent predictors of malignant ventricular arrhythmic events. A total of 18 (19%) ACM patients experienced 20 malignant ventricular arrhythmic events (4 aborted SCD, 8 SCD and 8 appropriate ICD therapies). At baseline evaluation, the only independent predictor of malignant ventricular arrhythmias in ACM patients was LBBB (OR 11.2; CI95%: 2.6-50; p=0.001). No malignant ventricular arrhythmias were recorded during follow-up in ACM patients if left ventricular ejection fraction (LVEF) had increased or remained ≥40%. Malignant ventricular arrhythmias are more frequent in ACM than in IDCM. LBBB identifies ACM patients with increased risk of SCD. No malignant ventricular arrhythmias were found during follow-up in ACM patients when LVEF was ≥40%. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effect of PR Interval on Outcomes Following Cardiac Resynchronization Therapy: A Secondary Analysis of the COMPANION Trial.

PubMed

Lin, Jeffrey; Buhr, Kevin A; Kipp, Ryan

2017-02-01

Prolonged PR intervals may impair atrioventricular mechanical coupling and adversely affect cardiac performance. We hypothesize that patients with advanced systolic heart failure, wide QRS complexes, and prolonged PR intervals will have improved survival from CRT-D regardless of whether left bundle branch block (LBBB) or non-LBBB is present. A total of 308 patients enrolled in the optimal pharmacologic therapy (OPT) and 595 patients in the cardiac resynchronization therapy with defibrillation (CRT-D) arms of the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure trial were stratified according to normal (≤230 ms) or prolonged PR interval (>230 ms). The incidence of all-cause mortality (ACM) or hospitalization (primary endpoint) and ACM (secondary endpoint) was compared using Kaplan-Meier curves. Cox proportional hazards models for the primary and secondary endpoints were fit with LBBB status and baseline PR interval. CRT-D treatment reduced both hospitalization/ACM (P = 0.002) and ACM (P = 0.003) compared to OPT. However, CRT-D was increasingly more effective in reducing ACM hazard in patients with longer baseline PR intervals (P = 0.002) regardless of LBBB status. In particular, in the prolonged baseline PR interval subgroup, ACM was reduced with CRT-D compared to OPT (P = 0.001) with little evidence of ACM reduction in the normal PR subgroup (P = 0.07). In patients with advanced systolic heart failure, wide QRS complexes, and prolonged PR intervals, restoration of atrioventricular mechanical coupling with CRT-D may improve survival regardless of LBBB status. In patients with non-LBBB, a benefit from CRT-D may occur with prolonged PR intervals. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Sleep-disordered breathing and daytime cardiac conduction abnormalities on 12-lead electrocardiogram in community-dwelling older men

PubMed Central

Kwon, Younghoon; Picel, Katherine; Adabag, Selcuk; Vo, Tien; Taylor, Brent C.; Redline, Susan; Stone, Katie; Mehra, Reena; Ancoli-Israel, Sonia

2016-01-01

Purpose Nocturnal cardiac conduction abnormalities are commonly observed in patients with sleep-disordered breathing (SDB). However, few population-based studies have examined the association between SDB and daytime cardiac conduction abnormalities. Methods We examined a random sample of 471 community-dwelling men, aged ≥67 years, enrolled in the multi-center Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study. SDB severity was categorized using percent of total sleep time with oxygen saturation <90 % (%TST < 90) and apnea hypopnea index (AHI). Cardiac conduction parameters were assessed by resting 12-lead electrocardiography (ECG). All analyses were adjusted for age, site, β-blocker use, coronary heart disease, calcium channel blocker use, and use of antiarrhythmic medications. Results Mean age was 77 ± 6 years, median %TST < 90 was 0.7 (IQR 0.00–3.40), and median AHI was 7.06 (IQR 2.55–15.32). Men with greater nocturnal hypoxemia (%TST < 90 ≥ 3.5 %) compared with those without hypoxemia (%TST < 90 < 1.0 %) had a lower odds of bradycardia (OR 0.55 [0.32–0.94]) and right bundle branch block (RBBB) (OR 0.24 [0.08–0.75]) but a higher odds of ventricular paced rhythm (OR 4.42 [1.29–15.19]). Heart rate (HR) increased in a graded manner with increasing %TST < 90 (p-trend 0.01) and increasing AHI (p-trend 0.006), but these gradients were small in absolute magnitude. There were no associations of SDB measures with other ECG conduction parameters. Conclusions Greater nocturnal hypoxemia in older men was associated with a lower prevalence of daytime sinus bradycardia and RBBB, a higher prevalence of ventricular paced rhythm, and higher resting HR. PMID:26971326

Predictive value of preoperative electrocardiography for perioperative cardiovascular outcomes in patients undergoing noncardiac, nonvascular surgery.

PubMed

Biteker, Murat; Duman, Dursun; Tekkeşin, Ahmet Ilker

2012-08-01

The utility of routine preoperative electrocardiography (ECG) for assessing perioperative cardiovascular risk in patients undergoing noncardiac, nonvascular surgery (NCNVS) is unclear. There would be an association between preoperative ECG and perioperative cardiovascular outcomes in patients undergoing NCNVS. A total of 660 patients undergoing NCNVS were prospectively evaluated. Patients age >18 years who underwent an elective, nonday case, open surgical procedure were enrolled. Troponin I concentrations and 12-lead ECG were evaluated the day before surgery, immediately after surgery, and on the first 5 postoperative days. Preoperative ECG showing atrial fibrillation, left or right bundle branch block, left ventricular hypertrophy, frequent premature ventricular complexes, pacemaker rhythm, Q-wave, ST-segment changes, or sinus tachycardia or bradycardia were classified as abnormal. The patients were followed up during hospitalization and were evaluated for the presence of perioperative cardiovascular events (PCE). Eighty patients (12.1%) experienced PCE. Patients with abnormal ECG findings had a greater incidence of PCE than those with normal ECG results (16% vs 6.4%; P < 0.001). Mean QTc interval was significantly longer in the patients who had PCE (436.6 ± 31.4 vs 413.3 ± 16.7 ms; P < 0.001). Univariate analysis showed a significant association between preoperative atrial fibrillation, pacemaker rhythm, ST-segment changes, QTc prolongation, and in-hospital PCE. However, only QTc prolongation (odds ratio: 1.15, 95% confidence interval: 1.06-1.2, P < 0.001) was an independent predictor of PCE according to the multivariate analysis. Every 10-ms increase in QTc interval was related to a 13% increase for PCE. Prolongation of the QTc interval on the preoperative ECG was related with PCE in patients undergoing NCNVS. © 2011 Wiley Periodicals, Inc.

An individual patient meta-analysis of five randomized trials assessing the effects of cardiac resynchronization therapy on morbidity and mortality in patients with symptomatic heart failure.

PubMed

Cleland, John G; Abraham, William T; Linde, Cecilia; Gold, Michael R; Young, James B; Claude Daubert, J; Sherfesee, Lou; Wells, George A; Tang, Anthony S L

2013-12-01

Cardiac resynchronization therapy (CRT) with or without a defibrillator reduces morbidity and mortality in selected patients with heart failure (HF) but response can be variable. We sought to identify pre-implantation variables that predict the response to CRT in a meta-analysis using individual patient-data. An individual patient meta-analysis of five randomized trials, funded by Medtronic, comparing CRT either with no active device or with a defibrillator was conducted, including the following baseline variables: age, sex, New York Heart Association class, aetiology, QRS morphology, QRS duration, left ventricular ejection fraction (LVEF), and systolic blood pressure. Outcomes were all-cause mortality and first hospitalization for HF or death. Of 3782 patients in sinus rhythm, median (inter-quartile range) age was 66 (58-73) years, QRS duration was 160 (146-176) ms, LVEF was 24 (20-28)%, and 78% had left bundle branch block. A multivariable model suggested that only QRS duration predicted the magnitude of the effect of CRT on outcomes. Further analysis produced estimated hazard ratios for the effect of CRT on all-cause mortality and on the composite of first hospitalization for HF or death that suggested increasing benefit with increasing QRS duration, the 95% confidence bounds excluding 1.0 at ∼140 ms for each endpoint, suggesting a high probability of substantial benefit from CRT when QRS duration exceeds this value. QRS duration is a powerful predictor of the effects of CRT on morbidity and mortality in patients with symptomatic HF and left ventricular systolic dysfunction who are in sinus rhythm. QRS morphology did not provide additional information about clinical response. NCT00170300, NCT00271154, NCT00251251.

Association of subclinical atherosclerosis using carotid intima-media thickness, carotid plaque, and coronary calcium score with left ventricular dyssynchrony: the multi-ethnic Study of Atherosclerosis.

PubMed

Sharma, Ravi K; Donekal, Sirisha; Rosen, Boaz D; Tattersall, Matthew C; Volpe, Gustavo J; Ambale-Venkatesh, Bharath; Nasir, Khurram; Wu, Colin O; Polak, Joseph F; Korcarz, Claudia E; Stein, James H; Carr, James; Watson, Karol E; Bluemke, David A; Lima, João A C

2015-04-01

The role of atherosclerosis in the progression of global left ventricular dysfunction and cardiovascular events has been well recognized. Left ventricular (LV) dyssynchrony is a measure of regional myocardial dysfunction. Our objective was to investigate the relationship of subclinical atherosclerosis with mechanical LV dyssynchrony in a population-based asymptomatic multi-ethnic cohort. Participants of the Multi-Ethnic Study of Atherosclerosis (MESA) at exam 5 were evaluated using 1.5T cardiac magnetic resonance (CMR) imaging, carotid ultrasound (n = 2062) for common carotid artery (CCA) and internal carotid artery (ICA) intima-media thickness (IMT), and cardiac computed tomography (n = 2039) for coronary artery calcium (CAC) assessment (Agatston method). Dyssynchrony indices were defined as the standard deviation of time to peak systolic circumferential strain (SD-TPS) and the difference between maximum and minimum (max-min) time to peak strain using harmonic phase imaging in 12 segments (3-slices × 4 segments). Multivariable regression analyses were performed to assess associations after adjusting for participant demographics, cardiovascular risk factors, LV mass, and ejection fraction. In multivariable analyses, SD-TPS was significantly related to measures of atherosclerosis, including CCA-IMT (8.7 ms/mm change in IMT, p = 0.020), ICA-IMT (19.2 ms/mm change in IMT, p < 0.001), carotid plaque score (1.2 ms/unit change in score, p < 0.001), and log transformed CAC+1 (0.66 ms/unit log-CAC+1, p = 0.018). These findings were consistent with other parameter of LV dyssynchrony i.e. max-min. In the MESA cohort, measures of atherosclerosis are associated with parameters of subclinical LV dyssynchrony in the absence of clinical coronary event and left-bundle-branch block. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Increased sensitivity of prolonged P-wave during exercise stress test in detection of angiographically documented coronary artery disease.

PubMed

Wsol, Agnieszka; Wydra, Wioletta; Chmielewski, Marek; Swiatowiec, Andrzej; Kuch, Marek

2017-01-01

A retrospective study was designed to investigate P-wave duration changes in exercise stress test (EST) for the prediction of angiographically documented substantial coronary artery disease (CAD). We analyzed 265 cases of patients, who underwent EST and subsequently coronary angiography. Analysis of P-wave duration was performed in leads II, V5 at rest, and in the recovery period. The sensitivity and specificity for the isolated ST-segment depression were only 31% and 76%, respectively. The combination of ST-depression with other exercise-induced clinical and electrocardio-graphic abnormalities (chest pain, ventricular arrhythmia, hypotension, left bundle branch block) was characterized by 41% sensitivity and 69% specificity. The combination of abnormal recovery P-wave duration (≥ 120 ms) with ST-depression and other exercise-induced abnormalities had 83% sensitivity but only 20% specificity. Combined analysis of increased delta P-wave duration, ST-depression and other exercise-induced abnormalities had 69% sensitivity and 42% specificity. Sensitivity and specificity of the increase in delta P-wave duration for left CAD was 69% and 47%, respectively, and for 3-vessel CAD 70% and 50%, respectively. The presence of arterial hypertension negatively influenced the prog-nostic value of P-wave changes in the stress test. The results of the study show that an addition of P-wave duration changes assessment to ST-depression analysis and other exercise-induced abnormalities increase sensitivity of EST, especially for left CAD and 3-vessel coronary disease. We have also provided evidence for the negative influence of the presence of arterial hypertension on the predictive value of P-wave changes in the stress test. (Cardiol J 2017; 24, 2: 159-166).

T-wave area as biomarker of clinical response to cardiac resynchronization therapy.

PubMed

Végh, Eszter M; Engels, Elien B; van Deursen, Caroline J M; Merkely, Béla; Vernooy, Kevin; Singh, Jagmeet P; Prinzen, Frits W

2016-07-01

There is increasing evidence that left bundle branch block (LBBB) morphology on the electrocardiogram is a positive predictor for response to cardiac resynchronization therapy (CRT). We previously demonstrated that the vectorcardiography (VCG)-derived T-wave area predicts echocardiographic CRT response in LBBB patients. In the present study, we investigate whether the T-wave area also predicts long-term clinical outcome to CRT. This is a retrospective study consisting of 335 CRT recipients. Primary endpoint were the composite of heart failure (HF) hospitalization, heart transplantation, left ventricular assist device implantation or death during a 3-year follow-up period. HF hospitalization and death alone were secondary endpoints. The patient subgroup with a large T-wave area and LBBB 36% reached the primary endpoint, which was considerably less (P < 0.01) than for patients with LBBB and a small T-wave area or non-LBBB patients with a small or large T-wave area (48, 57, and 51%, respectively). Similar differences were observed for the secondary endpoints, HF hospitalization (31 vs. 51, 51, and 38%, respectively, P < 0.01) and death (19 vs. 42, 34, and 42%, respectively, P < 0.01). In multivariate analysis, a large T-wave area and LBBB were the only independent predictors of the combined endpoint besides high creatinine levels and use of diuretics. T-wave area may be useful as an additional biomarker to stratify CRT candidates and improve selection of those most likely to benefit from CRT. A large T-wave area may derive its predictive value from reflecting good intrinsic myocardial properties and a substrate for CRT. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Management and outcome of patients with acute myocardial infarction presenting with pacemaker rhythm.

PubMed

Bertel, Noemi; Witassek, Fabienne; Puhan, Milo; Erne, Paul; Rickli, Hans; Naegeli, Barbara; Pedrazzini, Giovanni; Stauffer, Jean-Christophe; Radovanovic, Dragana

2017-03-01

Diagnosis of acute myocardial infarction (MI) is challenging in pacemaker patients. Little is known about this patient group. Patients with MI enrolled in the Swiss national AMIS Plus registry between January 2005 and December 2015 were analyzed. All patients with either paced ventricular rhythm or sinus rhythm with intrinsic ventricular conduction (IVC) were included in this study. Outcomes using crude data and propensity score matching were compared between patients with pacemaker rhythm and patients with IVC. The primary endpoint was in-hospital death. Data from 300 patients with paced rhythm and 27,595 with IVC were analyzed. Patients with pacemaker rhythm were older (78.2y vs 65.4y; p<0.001), had more comorbidities (Charlson Index (CCI)>1: 54.0% vs 21.1%; p<0.001) and a higher rate of heart failure upon presentation (Killip class>2, 11.0% vs 5.9%; p<0.001) compared to patients with IVC. Door to balloon time in patients undergoing acute PCI is markedly delayed in contrast to patients with IVC (280min vs 85min; p<0.001). Consequently, crude mortality in patients with pacemakers was high (11.3% vs 4.6%; p<0.001). However, when analyzed with propensity matching for gender, age, CCI>1 and Killip>2, mortality was similar (11.2% vs 10.5%; p=0.70). Pacemaker patients with acute MI represent a high-risk group with doubled crude mortality compared to patients without pacemakers, due to higher age and higher Killip class. Diagnosis is difficult and results in delayed treatment. Treatment algorithms for MI with paced rhythm should possibly be adapted to those used for STEMI or new left bundle branch block. NCT01305785. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Selvester scoring in patients with strict LBBB using the QUARESS software.

PubMed

Xia, Xiaojuan; Chaudhry, Uzma; Wieslander, Björn; Borgquist, Rasmus; Wagner, Galen S; Strauss, David G; Platonov, Pyotr; Ugander, Martin; Couderc, Jean-Philippe

2015-01-01

Estimation of the infarct size from body-surface ECGs in post-myocardial infarction patients has become possible using the Selvester scoring method. Automation of this scoring has been proposed in order to speed-up the measurement of the score and improving the inter-observer variability in computing a score that requires strong expertise in electrocardiography. In this work, we evaluated the quality of the QuAReSS software for delivering correct Selvester scoring in a set of standard 12-lead ECGs. Standard 12-lead ECGs were recorded in 105 post-MI patients prescribed implantation of an implantable cardiodefibrillator (ICD). Amongst the 105 patients with standard clinical left bundle branch block (LBBB) patterns, 67 had a LBBB pattern meeting the strict criteria. The QuAReSS software was applied to these 67 tracings by two independent groups of cardiologists (from a clinical group and an ECG core laboratory) to measure the Selvester score semi-automatically. Using various level of agreement metrics, we compared the scores between groups and when automatically measured by the software. The average of the absolute difference in Selvester scores measured by the two independent groups was 1.4±1.5 score points, whereas the difference between automatic method and the two manual adjudications were 1.2±1.2 and 1.3±1.2 points. Eighty-two percent score agreement was observed between the two independent measurements when the difference of score was within two point ranges, while 90% and 84% score agreements were reached using the automatic method compared to the two manual adjudications. The study confirms that the QuAReSS software provides valid measurements of the Selvester score in patients with strict LBBB with minimal correction from cardiologists. Copyright © 2015 Elsevier Inc. All rights reserved.

Electrocardiogram changes and atrial arrhythmias in individuals carrying sodium channel SCN5A D1275N mutation.

PubMed

Vanninen, Sari U M; Nikus, Kjell; Aalto-Setälä, Katriina

2017-09-01

The cardiac sodium channel SCN5A regulates atrioventricular and ventricular depolarization as well as cardiac conduction. Patients with cardiac electrical abnormalities have an increased risk of sudden cardiac death (SCD) and cardio-embolic stroke. Optimal management of cardiac disease includes the understanding of association between the causative mutations and the clinical phenotype. A 12-lead electrocardiogram (ECG) is an easy and inexpensive tool for finding risk patients. A blood sample for DNA extraction was obtained in a Finnish family with 43 members; systematic 12-lead ECG analysis was performed in 13 of the family members carrying an SCN5A D1275N mutation. Conduction defects and supraventricular arrhythmias, including atrial fibrillation/flutter, atrioventricular nodal re-entry tachycardia (AVNRT) and junctional rhythm were searched for. Five (38%) mutation carriers had fascicular or bundle branch block, 10 had atrial arrhythmias; no ventricular arrhythmias were found. Notching of the R- and S waves - including initial QRS fragmentation - and prolonged S-wave upstroke were present in all the affected family members. Notably, four (31%) affected family members had a stroke before the age of 31 and two experienced premature death. A 12-lead ECG can be used to predict arrhythmias in SCN5A D1275N mutation carriers. Key messages The 12-lead ECG may reveal cardiac abnormalities even before clinical symptoms occur. Specific ECG findings - initial QRS fragmentation, prolonged S-wave upstroke as well as supraventricular arrhythmias - were frequently encountered in all SCN5A D1257N mutation carriers. ECG follow-up is recommended for all SCN5A D1275N mutation carriers.

Prevalence of Electrocardiographic Patterns Associated With Sudden Cardiac Death in the Spanish Population Aged 40 Years or Older. Results of the OFRECE Study.

PubMed

Awamleh García, Paula; Alonso Martín, Joaquín Jesús; Graupner Abad, Catherine; Jiménez Hernández, Rosa María; Curcio Ruigómez, Alejandro; Talavera Calle, Pedro; Cristóbal Varela, Carmen; Serrano Antolín, José; Muñiz, Javier; Gómez Doblas, Juan José; Roig, Eulalia

2017-10-01

Some electrocardiographic patterns are associated with an increased risk of sudden cardiac death due to ventricular arrhythmias. There is no information on the prevalence of these patterns in the general population in Spain. The objective of this study was to analyze the prevalence of these patterns and associated clinical and epidemiological factors. This subanalysis of the OFRECE study selected a representative sample of the Spanish population aged ≥ 40 years. We studied the presence or absence of electrocardiographic patterns of Brugada syndrome and QT interval abnormalities. Clinical data and electrocardiograms were available in all participants. Electrocardiograms were evaluated by 2 cardiologists and a third cardiologist was consulted if there was disagreement in the diagnosis. We calculated the weighted prevalence and clinical factors associated with the presence of Brugada-type patterns or QT segment abnormalities. Overall, 8343 individuals were evaluated (59.2 years, 52.4% female). There were 12 Brugada cases (type 1, 2 cases; type 2, 10 cases; weighted prevalence, 0.13%). For corrected QT (QTc) analysis, we excluded participants with left bundle branch block or without sinus rhythm. Weighted prevalences were as follows: short QTc (< 340ms) 0.18%, borderline QTc (441-469ms) 8.33%, long QTc (≥ 470ms criterion) 1.01% and long QTc (≥ 480 criterion) 0.42%. A total of 0.6% to 1.1% of the Spanish population aged ≥ 40 years has an electrocardiographic pattern associated with a higher risk of sudden death (Brugada syndrome, long QT, or short QT). Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Role of electrocardiographic changes in discriminating acute or chronic right ventricular pressure overload.

PubMed

Can, Mehmet Mustafa; Özveren, Olcay; Biteker, Murat; Şengül, Cihan; Uz, Ömer; Işılak, Zafer; Kırılmaz, Ata

2013-06-01

Pulmonary embolism (PE) and severe pulmonary stenosis (PS) are two distinct conditions accompanied by increased pressure load of the right ventricle (RV). Despite major advances in our understanding of the mechanisms of RV adaptation to the increased pressure, substantial gaps in our knowledge remain unsettled. One of much less known aspect of pressure overload of RV is its impact on electrocardiographic (ECG) changes. In this study, we aimed to study whether acute and chronic RV overload are accompanied by different ECG patterns. Thirty-eight patients with PE underwent ECG monitoring were compared with 20 matched patients with PS in this observational retrospective study. ECG abnormalities suggestive of RV overload were recorded and analyzed in both groups. Logistic regression analysis was used to define the predictors of chronic RV overload. Among the ECG changes studied, premature atrial contraction (OR-12.2, 95% CI, 1.3-107, p=0.008), right axis deviation (OR-20.4, 95% CI 4.2-98, p<0.001), indeterminate axis (OR-0.11, 95% CI 0.02-0.44, p=0.001 0.11), incomplete right bundle branch block (OR-4.2, 95% CI, 1.1-15.4, p=0.02), late R in aVR (OR-8.4, 95% CI 2.1-33.2, p=0.001), qR in V1 lead (OR-8.3, 95% CI 1.2-74.8, p=0.03) were found to be the independent predictors of chronic RV pressure overload. Our data indicate that the ECG changes that attributed to the acute RV pressure loading states may be more prevalent in chronic RV overload as compared with acute RV overload.

Sleep-disordered breathing and daytime cardiac conduction abnormalities on 12-lead electrocardiogram in community-dwelling older men.

PubMed

Kwon, Younghoon; Picel, Katherine; Adabag, Selcuk; Vo, Tien; Taylor, Brent C; Redline, Susan; Stone, Katie; Mehra, Reena; Ancoli-Israel, Sonia; Ensrud, Kristine E

2016-12-01

Nocturnal cardiac conduction abnormalities are commonly observed in patients with sleep-disordered breathing (SDB). However, few population-based studies have examined the association between SDB and daytime cardiac conduction abnormalities. We examined a random sample of 471 community-dwelling men, aged ≥67 years, enrolled in the multi-center Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study. SDB severity was categorized using percent of total sleep time with oxygen saturation <90 % (%TST < 90) and apnea hypopnea index (AHI). Cardiac conduction parameters were assessed by resting 12-lead electrocardiography (ECG). All analyses were adjusted for age, site, β-blocker use, coronary heart disease, calcium channel blocker use, and use of antiarrhythmic medications. Mean age was 77 ± 6 years, median %TST < 90 was 0.7 (IQR 0.00-3.40), and median AHI was 7.06 (IQR 2.55-15.32). Men with greater nocturnal hypoxemia (%TST < 90 ≥ 3.5 %) compared with those without hypoxemia (%TST < 90 < 1.0 %) had a lower odds of bradycardia (OR 0.55 [0.32-0.94]) and right bundle branch block (RBBB) (OR 0.24 [0.08-0.75]) but a higher odds of ventricular paced rhythm (OR 4.42 [1.29-15.19]). Heart rate (HR) increased in a graded manner with increasing %TST < 90 (p-trend 0.01) and increasing AHI (p-trend 0.006), but these gradients were small in absolute magnitude. There were no associations of SDB measures with other ECG conduction parameters. Greater nocturnal hypoxemia in older men was associated with a lower prevalence of daytime sinus bradycardia and RBBB, a higher prevalence of ventricular paced rhythm, and higher resting HR.

The Shortest QRS Duration of an Electrocardiogram Might Be an Optimal Electrocardiographic Predictor for Response to Cardiac Resynchronization Therapy.

PubMed

Chen, Jan-Yow; Lin, Kuo-Hung; Chang, Kuan-Cheng; Chou, Che-Yi

2017-08-03

QRS duration has been associated with the response to cardiac resynchronization therapy (CRT). However, the methods for defining QRS duration to predict the outcome of CRT have discrepancies in previous reports. The aim of this study was to determine an optimal measurement of QRS duration to predict the response to CRT.Sixty-one patients who received CRT were analyzed. All patients had class III-IV heart failure, left ventricular ejection fraction not more than 35%, and complete left bundle branch block. The shortest, longest, and average QRS durations from the 12 leads of each electrocardiogram (ECG) were measured. The responses to CRT were determined using the changes in echocardiography after 6 months. Thirty-five (57.4%) patients were responders and 26 (42.6%) patients were non-responders. The pre-procedure shortest, average, and longest QRS durations and the QRS shortening (ΔQRS) of the shortest QRS duration were significantly associated with the response to CRT in a univariate logistic regression analysis (P = 0.002, P = 0.03, P = 0.04 and P = 0.04, respectively). Based on the measurement of the area under curve of the receiver operating characteristic curve, only the pre-procedure shortest QRS duration and the ΔQRS of the shortest QRS duration showed significant discrimination for the response to CRT (P = 0.002 and P = 0.038, respectively). Multivariable logistic regression showed the pre-procedure shortest QRS duration is an independent predictor for the response to CRT.The shortest QRS duration from the 12 leads of the electrocardiogram might be an optimal measurement to predict the response to CRT.

Effect of cardiac resynchronization therapy on beat-to-beat T-wave amplitude variability.

PubMed

Žižek, David; Cvijić, Marta; Tasič, Jerneja; Jan, Matevž; Frljak, Sabina; Zupan, Igor

2012-11-01

T-wave amplitude variability (TAV) is a promising non-invasive predictor of arrhythmic events in patients with dilated cardiomyopathy. We aimed to evaluate the effect of cardiac resynchronization therapy (CRT) on native TAV, its relation with left ventricular (LV) reverse remodelling and the occurrence of ventricular tachyarrhythmias (VTs). In this prospective study, we included 40 heart failure patients with left bundle branch block in sinus rhythm (25 male; 16 with ischaemic aetiology; aged 62.7 ± 9.5 years; New York Heart Association class II-IV). Echocardiographic parameters and TAV were evaluated at baseline and 6 months after implantation of CRT device combined with an implantable cardioverter-defibrillator. T-wave amplitude variability was determined by a 20-min high-resolution electrocardiogram Holter recording during native conduction. After TAV assessment, patients were monitored for 15.7 ± 5.2 months for the occurrence of VTs. Decrease in median TAV [from 40.45 μV (24.75-56.00) to 28.15 μV (20.93-37.95), P = 0.004] was observed after 6 months of CRT. However, decrease of median TAV was only noticed in patients with LV reverse remodelling [46.9 μV (27.5-70.0) to 25.8 μV (20.2-32.4), P < 0.001] and in patients without VTs [40.5 μV (27.5-55.9) to 24.4 μV (17.1-31.5), P < 0.001]. Native median TAV > 35.4 µV after 6 months of CRT had an 83% sensitivity and 93% specificity for predicting the occurrence of VTs. Decrease of TAV after CRT is associated with LV reverse remodelling and indicates a reduction of the intrinsic arrhythmogenic substrate. Median TAV after CRT had a good predicting value for VT occurrence in long-term follow-up.

Left ventricular lead placement in the latest activated region guided by coronary venous electroanatomic mapping.

PubMed

Rad, Masih Mafi; Blaauw, Yuri; Dinh, Trang; Pison, Laurent; Crijns, Harry J; Prinzen, Frits W; Vernooy, Kevin

2015-01-01

Left ventricular (LV) lead placement in the latest activated region is an important determinant of response to cardiac resynchronization therapy (CRT). We investigated the feasibility of coronary venous electroanatomic mapping (EAM) to guide LV lead placement to the latest activated region. Twenty-five consecutive CRT candidates with left bundle-branch block underwent intra-procedural coronary venous EAM using EnSite NavX. A guidewire was used to map the coronary veins during intrinsic activation, and to test for phrenic nerve stimulation (PNS). The latest activated region, defined as the region with an electrical delay >75% of total QRS duration, was located anterolaterally in 18 (basal, n = 10; mid, n = 8) and inferolaterally in 6 (basal, n = 3; mid, n = 3). In one patient, identification of the latest activated region was impeded by limited coronary venous anatomy. In patients with >1 target vein (n = 12), the anatomically targeted inferolateral vein was rarely the vein with maximal electrical delay (n = 3). A concordant LV lead position was achieved in 18 of 25 patients. In six patients, this was hampered by PNS (n = 4), lead instability (n = 1), and coronary vein stenosis (n = 1). Coronary venous EAM can be used intraprocedurally to guide LV lead placement to the latest activated region free of PNS. This approach especially contributes to optimization of LV lead electrical delay in patients with multiple target veins. Conventional anatomical LV lead placement strategy does not target the vein with maximal electrical delay in many of these patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Clinical Characteristics and Prognosis of End-stage Hypertrophic Cardiomyopathy.

PubMed

Xiao, Yan; Yang, Kun-Qi; Yang, Yan-Kun; Liu, Ya-Xin; Tian, Tao; Song, Lei; Jiang, Xiong-Jing; Zhou, Xian-Liang

2015-06-05

End-stage hypertrophic cardiomyopathy (HCM) is complicated by substantial adverse events. However, few studies have focused on electrocardiographic features and their prognostic values in HCM. This study aimed to evaluate the clinical manifestations and prognostic value of electrocardiography in patients with end-stage HCM. End-stage HCM patients were enrolled from a total of 1844 consecutive HCM patients from April 2002 to November 2013 at Fuwai Hospital. Clinical data, including medical history, electrocardiography, and echocardiography, were analyzed. Cox hazards regression analysis was used to assess the risk factors for cardiovascular mortality. End-stage HCM was identified in 99 (5.4%) patients, averaged at 52 ± 16 years old at entry. Atrial fibrillation was observed in 53 patients and mural thrombus in 19 patients. During 3.9 ± 3.0 years of follow-up, embolic stroke, refractory heart failure, and death or transplantation were observed in 20, 39, and 51 patients, respectively. The incidence of annual mortality was 13.2%. Multivariate Cox hazards regression analysis identified New York Heart Association Class (NYHA) III/IV at entry (hazard ratio [HR]: 1.99; 95% confidence interval [CI]: 1.05-3.80; P = 0.036), left bundle branch block (LBBB) (HR: 2.80; 95% CI: 1.47-5.31; P = 0.002), and an abnormal Q wave (HR: 2.21; 95% CI: 1.16-4.23; P = 0.016) as independent predictors of cardiovascular death, in accordance with all-cause death and heart failure-related death. LBBB and an abnormal Q wave are risk factors of cardiovascular mortality in end-stage HCM and provide new evidence for early intervention. Susceptibility of end-stage HCM patients to mural thrombus and embolic events warrants further attention.

Acute hemodynamic effects of right and left ventricular lead positions during the implantation of cardiac resynchronization therapy defibrillators.

PubMed

Stockinger, Jochem; Staier, Klaus; Schiebeling-Römer, Jochen; Keyl, Cornelius

2011-11-01

To evaluate the acute hemodynamic effects of different right (RV) and left ventricular (LV) pacing sites in patients undergoing the implantation of a cardiac resynchronization therapy defibrillator (CRT-D). Stroke volume index (SVI), assessed via pulse contour analysis, and dp/dt max, obtained in the abdominal aorta, were analyzed in 21 patients with New York Heart Association class III heart failure and left bundle branch block (mean ejection fraction of 24 ± 6%), scheduled for CRT-D implantation under general anesthesia. We compared the hemodynamic effects of RV apical (A), RV septal (B), and biventricular pacing using the worst (lowest SVI; C) and best (highest SVI; D) coronary sinus lead positions. Mean arterial pressure, SVI, and dp/dt max did not differ significantly between RV apical and septal pacing. Dp/dt max and SVI increased significantly during biventricular pacing (dp/dt max: B, 588 ± 160 mmHg/s; C, 651 ± 218 mmHg/s, P = 0.03 vs B; D, 690 ± 220 mmHg/s, P = 0.02 vs C; SVI: B, 33.6 ± 5.5 mL/m², C, 34.8 ± 6.1 mL/m², P = 0.08 vs B, D 36.0 ± 6.0 mL/m², P < 0.001 vs C). The best hemodynamic response was associated with lateral or inferior lead positions in 15 patients. Other LV lead positions were most effective in six patients. The optimal LV lead position varies significantly among patients and should be individually determined during CRT-D implantation. The impact of the RV stimulation site in patients with intraventricular conduction delay, undergoing CRT-D implantation, has to be investigated in further studies.

Analysis of Electrocardiograms Associated with Pediatric Electrical Burns.

PubMed

McLeod, Jennifer S; Maringo, Alison E; Doyle, Patrick J; Vitale, Lisa; Klein, Justin D; Shanti, Christina M

2017-05-26

The purpose of this study was to examine the utility of electrocardiograms (EKGs) for low-risk, low-voltage pediatric electrical burn victims. A retrospective chart review was conducted on 86 pediatric patients who presented to the children's hospital between 2000 and 2015 after sustaining electrical burns. Variables included source and estimated voltage, extent of injuries, length of stay, high risk factors, and EKG results. High risk factors included estimated voltage > 1000 V, lightning, tetany, symptoms, loss of consciousness, or seizures. Statistical analyses were conducted. Average age was 5 years. Of those who sustained burns, 84.5% (n = 71/84) had second-degree burns ≤ 1% TBSA or less. Eleven patients had high risk factors, 12.9% (n = 11/85) and most had length of stay < 3 days (91.8%; n = 78/85). Majority sustained burns from low-voltage (< 300 V) household electrical outlets, cords, or light bulb sockets (90.4%; n = 75/83). Among patients with available EKGs, 12 had arrhythmias on initial EKG (i.e., low right atrial rhythm, t-wave inversions, sinus tachycardia, bundle branch block; 20.7%; n = 12/58). All were transient and nonfatal. The data suggest that low estimated voltage (< 300 V) electrical injuries were associated with negative EKGs; however, due to the low rate of arrhythmias, a Fisher's exact test did not show significance, P = 0.09 (P > 0.05). Preliminary data suggest that most pediatric electrical burns are due to low voltage (< 300 V) household sources. Few have high risk factors or arrhythmias that were transient and nonfatal. These data suggest that low-risk, asymptomatic, low-voltage pediatric electrical burns may not require an initial screening EKG.

"A Tale of Two Planes": Deep Versus Superficial Serratus Plane Block for Postmastectomy Pain Syndrome.

PubMed

Piracha, Mohammad M; Thorp, Stephen L; Puttanniah, Vinay; Gulati, Amitabh

Postmastectomy pain syndrome (PMPS) is a significant burden for breast cancer survivors. Although multiple therapies have been described, an evolving field of serratus anterior plane blocks has been described in this population. We describe the addition of the deep serratus anterior plane block (DSPB) for PMPS. Four patients with history of PMPS underwent DSPB for anterior chest wall pain. A retrospective review of these patients' outcomes was obtained through postprocedure interviews. Three of the patients previously had a superficial serratus anterior plane block, which was not as efficacious as the DSPB. The fourth patient had a superficial serratus anterior plane that was difficult to separate with hydrodissection but had improved pain control with a DSPB. We illustrate 4 patients who have benefitted from a DSPB and describe indications that this block may be more efficacious than a superficial serratus plane block. Further study is recommended to understand the intercostal nerve branches within the lateral and anterior muscular chest wall planes.

Two-Dimensional Liquid Chromatography Analysis of Polystyrene/Polybutadiene Block Copolymers.

PubMed

Lee, Sanghoon; Choi, Heejae; Chang, Taihyun; Staal, Bastiaan

2018-05-15

A detailed characterization of a commercial polystyrene/polybutadiene block copolymer material (Styrolux) was carried out using two-dimensional liquid chromatography (2D-LC). The Styrolux is prepared by statistical linking reaction of two different polystyrene- block-polybutadienyl anion precursors with a multivalent linking agent. Therefore, it is a mixture of a number of branched block copolymers different in molecular weight, composition, and chain architecture. While individual LC analysis, including size exclusion chromatography, interaction chromatography, or liquid chromatography at critical condition, is not good enough to resolve all the polymer species, 2D-LC separations coupling two chromatography methods were able to resolve all polymer species present in the sample; at least 13 block copolymer species and a homopolystyrene blended. Four different 2D-LC analyses combining a different pair of two LC methods provide their characteristic separation results. The separation characteristics of the 2D-LC separations are compared to elucidate the elution characteristics of the block copolymer species.

Structure-property relationships in a series of diglycerol tetraether model lipids and their lyotropic assemblies: the effect of branching topology and chirality.

PubMed

Markowski, Thomas; Drescher, Simon; Meister, Annette; Blume, Alfred; Dobner, Bodo

2014-06-14

Three novel diglycerol tetraether lipids with one membrane-spanning chain have been synthesized. These lipids contain only two or four racemic methyl branches at selected positions of the hydrophobic chains in contrast to natural lipids from archaebacterial membranes with an isoprenoid substitution pattern. The insertion of the methyl moieties was realized starting from either (RS)-citronellyl bromide or the inexpensive methyl malonic acid ethyl ester. For chain elongation the Cu-catalysed Grignard coupling reaction was used. The preparation of diglycerol tetraethers was either performed by condensing suitable blocked monoglycerol diethers by Grubbs metathesis or by reaction of the transmembrane C32-chain with blocked glycerols followed by further alkylation steps. Finally, we could show that the resulting lipids can form closed lipid vesicles comparable to the optically pure counterparts. Therefore, these much simpler lipids compared to the natural lipids from archaebacterial membranes are also suitable for preparation of stable tailored liposomes.

Present-day kinematics of the Danakil block (southern Red Sea-Afar) constrained by GPS

NASA Astrophysics Data System (ADS)

Ladron de Guevara, R.; Jonsson, S.; Ruch, J.; Doubre, C.; Reilinger, R. E.; Ogubazghi, G.; Floyd, M.; Vasyura-Bathke, H.

2017-12-01

The rifting of the Arabian plate from the Nubian and Somalian plates is primarily accommodated by seismic and magmatic activity along two rift arms of the Afar triple junction (the Red Sea and Gulf of Aden rifts). The spatial distribution of active deformation in the Afar region have been constrained with geodetic observations. However, the plate boundary configuration in which this deformation occurs is still not fully understood. South of 17°N, the Red Sea rift is composed of two parallel and overlapping rift branches separated by the Danakil block. The distribution of the extension across these two overlapping rifts, their potential connection through a transform fault zone and the counterclockwise rotation of the Danakil block have not yet been fully resolved. Here we analyze new GPS observations from the Danakil block, the Gulf of Zula area (Eritrea) and Afar (Ethiopia) together with previous geodetic survey data to better constrain the plate kinematics and active deformation of the region. The new data has been collected in 2016 and add up to 5 years to the existing geodetic observations (going back to 2000). Our improved GPS velocity field shows differences with previously modeled GPS velocities, suggesting that the rate and rotation of the Danakil block need to be updated. The new velocity field also shows that the plate-boundary strain is accommodated by broad deformation zones rather than across sharp boundaries between tectonic blocks. To better determine the spatial distribution of the strain, we first implement a rigid block model to constrain the overall regional plate kinematics and to isolate the plate-boundary deformation at the western boundary of the Danakil block. We then study whether the recent southern Red Sea rifting events have caused detectable changes in observed GPS velocities and if the observations can be used to constrain the scale of this offshore rift activity. Finally, we investigate different geometries of transform faults that might connect the two overlapping branches of the southern Red Sea rift in the Gulf of Zula region.

Comparative study of the novel and conventional injection approach for inferior alveolar nerve block.

PubMed

Boonsiriseth, K; Sirintawat, N; Arunakul, K; Wongsirichat, N

2013-07-01

This study aimed to evaluate the efficacy of anesthesia obtained with a novel injection approach for inferior alveolar nerve block compared with the conventional injection approach. 40 patients in good health, randomly received each of two injection approaches of local anesthetic on each side of the mandible at two separate appointments. A sharp probe and an electric pulp tester were used to test anesthesia before injection, after injection when the patients' sensation changed, and 5 min after injection. This study comprised positive aspiration and intravascular injection 5% and neurovascular bundle injection 7.5% in the conventional inferior alveolar nerve block, but without occurrence in the novel injection approach. A visual analog scale (VAS) pain assessment was used during injection and surgery. The significance level used in the statistical analysis was p<0.05. For the novel injection approach compared with the conventional injection approach, no significant difference was found on the subjective onset, objective onset, operation time, duration of anesthesia and VAS pain score during operation, but the VAS pain score during injection was significantly different. The efficacy of inferior alveolar nerve block by the novel injection approach provided adequate anesthesia and caused less pain and greater safety during injection. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.