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Sample records for isolated ventricular noncompaction

  1. [Isolated left ventricular noncompaction causing refractory heart failure].

    PubMed

    Meneguz-Moreno, Rafael Alexandre; Rodrigues da Costa Teixeira, Felipe; Rossi Neto, João Manoel; Finger, Marco Aurélio; Casadei, Carolina; Castillo, Maria Teresa; Sanchez de Almeida, Antonio Flávio

    2016-03-01

    Left ventricular noncompaction is a rare congenital anomaly characterized by excessive left ventricular trabeculation, deep intertrabecular recesses and a thin compacted layer due to the arrest of compaction of myocardial fibers during embryonic development. We report the case of a young patient with isolated left ventricular noncompaction, leading to refractory heart failure that required extracorporeal membrane oxygenation followed by emergency heart transplantation. PMID:26928017

  2. Anesthetic experience of patient with isolated left ventricular noncompaction: a case report

    PubMed Central

    Kim, Doyeon; Kim, Eunhee; Lee, Jong-Hwan; Lee, Sangmin Maria; Lee, Jung Eun

    2016-01-01

    Isolated left ventricular noncompaction (LVNC) is a rare primary genetic cardiomyopathy characterized by prominent trabeculation of the left ventricular wall and intertrabecular recesses. Perioperative management of the patient with LVNC might be challenging due to the clinical symptoms of heart failure, systemic thromboembolic events, and fatal left ventricular arrhythmias. We conducted real time intraoperative transesophageal echocardiography in a patient with LVNC undergoing general anesthesia for ovarian cystectomy. PMID:27274374

  3. Effects of carvedilol on left ventricular function, mass, and scintigraphic findings in isolated left ventricular non-compaction

    PubMed Central

    Toyono, M; Kondo, C; Nakajima, Y; Nakazawa, M; Momma, K; Kusakabe, K

    2001-01-01

    A four month old infant with isolated left ventricular non-compaction was treated with carvedilol. Haemodynamic studies and various types of imaging—including echocardiography, radiographic angiography, magnetic resonance imaging, and single photon emission computed tomography with 201Tl, 123I-β-methyliodophenylpentadecanoic acid (BMIPP), and 123I-metaiodobenzylguanidine (MIBG)—were performed before and 14 months after treatment. Left ventricular ejection fraction increased from 30% to 57%, and left ventricular end diastolic volume, end systolic volume, and end diastolic pressure showed striking reductions during treatment. Left ventricular mass decreased to about two thirds of the baseline value after treatment. Per cent wall thickening increased after carvedilol in the segments corresponding to non-compacted myocardium. A mismatch between 201Tl and BMIPP uptake in the area of non-compaction observed before carvedilol disappeared after treatment. Impaired sympathetic neuronal function shown by MIBG recovered after treatment. Thus carvedilol had beneficial effects on left ventricular function, hypertrophy, and both metabolic and adrenergic abnormalities in isolated left ventricular non-compaction.


Keywords: isolated left ventricular non-compaction; carvedilol; cardiac sympathetic nerve; ventricular remodelling PMID:11410581

  4. Echocardiographic and pathoanatomical characteristics of isolated left ventricular non-compaction: a step towards classification as a distinct cardiomyopathy

    PubMed Central

    Jenni, R; Oechslin, E; Schneider, J; Jost, C; Kaufmann, P

    2001-01-01

    AIM—To determine clear cut echocardiographic criteria for isolated ventricular non-compaction (IVNC), a cardiomyopathy as yet "unclassified" by the World Health Organization. The disease is not widely known and its diagnosis mostly missed.
METHODS AND RESULTS—In seven out of a series of 34 patients with IVNC the in vivo echocardiographic characteristics were validated against the anatomical examination of the heart removed after death in four and due to heart transplantation in three patients. Four morphological criteria diagnostic for IVNC were found. (1) Coexisting cardiac abnormalities were absent (by definition). (2) A two layer structure was seen, with a compacted thin epicardial band and a much thicker non-compacted endocardial layer of trabecular meshwork with deep endomyocardial spaces. A maximal end systolic ratio of non-compacted to compacted layers of > 2 is diagnostic. (3) The predominant localisation of the pathology was to mid-lateral (seven of seven patients), apical (six), and mid-inferior (seven) areas. The pathological preparations confirmed the echocardiographic findings. Concomitant regional hypokinesia was not confined to the non-compacted segments. (4) There was colour Doppler evidence of deep perfused intertrabecular recesses.
CONCLUSIONS—Four clear cut echocardiographic diagnostic criteria were established. It is suggested that the WHO classification of cardiomyopathies be reconsidered to include IVNC as a distinct cardiomyopathy.


Keywords: isolated ventricular non-compaction; morphological criteria; cardiomyopathy; echocardiography; pathology PMID:11711464

  5. Unusual distribution of noncompaction of left ventricular myocardium.

    PubMed

    Bhardwaj, Ravindra; Abro, Masroor; Gharib, Wissam; Warden, Bradford E; Jain, Abnash; Failinger, Conard F

    2015-01-01

    This case report highlights a rare case of isolated septal noncompaction of the left ventricle, a congenital condition, in a previously asymptomatic adult patient who presented with syncope. Management of left ventricular noncompaction (LVNC) includes treatment for heart failure, arrhythmias, and thromboembolic events; but no criteria exist for primary prophylaxis in patients that might be at high risk. To our knowledge this is the first report of isolated septal noncompaction in a previously asymptomatic adult patient. PMID:25665274

  6. Left ventricular noncompaction: A rare indication for pediatric heart transplantation.

    PubMed

    Magalhães, Mariana; Costa, Patrícia; Vaz, Maria Teresa; Pinheiro Torres, José; Areias, José Carlos

    2016-01-01

    Isolated left ventricular noncompaction is a rare congenital cardiomyopathy, characterized morphologically by a dilated left ventricle, prominent trabeculations and deep intertrabecular recesses in the ventricular myocardium, with no other structural heart disease. It is thought to be secondary to an arrest of normal myocardial compaction during fetal life. Clinically, the disease presents with heart failure, embolic events, arrhythmias or sudden death. Current diagnostic criteria are based on clinical and imaging data and two-dimensional and color Doppler echocardiography is the first-line exam. There is no specific therapy and treatment is aimed at associated comorbidities. Cases refractory to medical therapy may require heart transplantation. The authors describe a case of severe and refractory heart failure, which was the initial presentation of isolated left ventricular noncompaction in a previously healthy male child, who underwent successful heart transplantation. PMID:26777414

  7. Speckle myocardial imaging modalities for early detection of myocardial impairment in isolated left ventricular non-compaction

    PubMed Central

    Bellavia, Diego; Michelena, Hector I; Martinez, Matthew; Pellikka, Patricia A; Bruce, Charles J; Connolly, Heidi M; Villarraga, Hector R; Veress, Gabriella; Oh, Jae K; Miller, Fletcher A

    2013-01-01

    Objective To examine the hypothesis that speckle myocardial imaging (SMI) modalities, including longitudinal, radial and circumferential systolic (s) and diastolic (d) myocardial velocity imaging, displacement (D), strain rate (SR) and strain (S), as well as left ventricular (LV) rotation/torsion are sensitive for detecting early myocardial dysfunction in isolated LV non-compaction (iLVNC). Design and results Twenty patients with iLVNC diagnosed by cardiac magnetic resonance (15) or echocardiography (5) were included. Patients were divided into two groups: ejection fraction (EF)>50% (n=10) and EF≤50% (n=10). Standard measures of systolic and diastolic function including pulsed wave tissue Doppler Imaging (PWTDI) were obtained. Longitudinal, radial and circumferential SMI, and LV rotation/torsion were compared with values for 20 age/sex-matched controls. EF, PWTDI E′, E/E′ and all of the SMI modalities were significantly abnormal for patients with EF≤50% compared with controls. In contrast, EF and PWTDI E′, E/E′ were not significantly different between controls and patients with iLVNC (EF>50%). However, SMI-derived longitudinal sS, sSR, sD and radial sS, as well as LV rotation/torsion values, were all reduced in iLVNC (EF>50%) compared with controls. Measurements with the highest discriminating power between iLVNC (EF>50%) and controls were longitudinal sS mean of the six apical segments (area under the curve (AUC)=0.94), sS global average (AUC=0.94), LV rotation apical mean (AUC=0.94); LV torsion (AUC=0.93) LV torsion rate (AUC=0.94). Conclusions LV SMI values are reduced in patients with iLVNC, even those with normal EF and PWTDI. The most accurate SMI modalities to discriminate between patients and controls are longitudinal sS mean of the six apical segments, LV apical rotation or LV torsion rate. PMID:19966109

  8. Left Ventricular Non-compaction with Multiple Ventricular Septal Defects

    PubMed Central

    Moorthy, Nagaraja; Jain, Sandeep; Neyaz, Zafar; Kumar, Sunil; Goel, Pravin K.

    2015-01-01

    Left ventricular non-compaction (LVNC) is a congenital cardiomyopathy characterized by deep ventricular trabeculations thought to be due to an arrest of myocardial morphogenesis. Integration of various cardiac imaging modalities such as echocardiography, cardiac computed tomography and cardiac magnetic resonance imaging help in the diagnosis of this rare clinical entity. We describe a child with rare variant of LVNC with predominant involvement of interventricular septum resulting in multiple ventricular septal defects. PMID:27326350

  9. Left Ventricular Noncompaction: A Distinct Genetic Cardiomyopathy?

    PubMed

    Arbustini, Eloisa; Favalli, Valentina; Narula, Nupoor; Serio, Alessandra; Grasso, Maurizia

    2016-08-30

    Left ventricular noncompaction (LVNC) describes a ventricular wall anatomy characterized by prominent left ventricular (LV) trabeculae, a thin compacted layer, and deep intertrabecular recesses. Individual variability is extreme, and trabeculae represent a sort of individual "cardioprinting." By itself, the diagnosis of LVNC does not coincide with that of a "cardiomyopathy" because it can be observed in healthy subjects with normal LV size and function, and it can be acquired and is reversible. Rarely, LVNC is intrinsically part of a cardiomyopathy; the paradigmatic examples are infantile tafazzinopathies. When associated with LV dilation and dysfunction, hypertrophy, or congenital heart disease, the genetic cause may overlap. The prevalence of LVNC in healthy athletes, its possible reversibility, and increasing diagnosis in healthy subjects suggests cautious use of the term LVNC cardiomyopathy, which describes the morphology but not the functional profile of the cardiomyopathy. PMID:27561770

  10. The Current Approach to Diagnosis and Management of Left Ventricular Noncompaction Cardiomyopathy: Review of the Literature

    PubMed Central

    Bennett, Courtney E.; Freudenberger, Ronald

    2016-01-01

    Isolated left ventricular noncompaction (LVNC) is a genetic cardiomyopathy characterized by prominent ventricular trabeculations and deep intertrabecular recesses, or sinusoids, in communication with the left ventricular cavity. The low prevalence of patients with this cardiomyopathy presents a unique challenge for large, prospective trials to assess its pathogenesis, management, and outcomes. In this paper we review the embryology and genetics of LVNC, the diagnostic approach, and propose a management approach based on the current literature available. PMID:26881173

  11. Left Ventricular Non-compaction in Holt-Oram Syndrome.

    PubMed

    Kapadia, Renuka; Choudhary, Preeti; Collins, Nicholas; Celermajer, David; Puranik, Rajesh

    2016-06-01

    Holt-Oram Syndrome is an autosomal dominant condition with complete penetrance and which involves upper limb skeletal and cardiac abnormalities. The latter can be structural defects or involve the conduction system. This report details the occurrence of left ventricular non-compaction in multiple family members with Holt-Oram Syndrome. It is recommended that patients with the Holt-Oram Syndrome be considered for comprehensive cardiac evaluation to exclude non-compaction cardiomyopathy as this may have significant prognostic implications. PMID:26874791

  12. Left ventricular noncompaction: a new form of heart failure.

    PubMed

    Towbin, Jeffrey A

    2010-10-01

    In this article the newly classified cardiomyopathy known as left ventricular noncompaction is discussed. This genetic inherited form of heart disease has substantial risk of heart failure, stroke, metabolic derangement, arrhythmias, and sudden cardiac death. The disorder seems to occur because of an arrest of the normal process of development, and the genes identified to date seem to encode for cytoskeletal or sarcomeric proteins. These features are outlined. PMID:20869646

  13. Ebstein's Anomaly, Left Ventricular Noncompaction, and Sudden Cardiac Death.

    PubMed

    McGee, Michael; Warner, Luke; Collins, Nicholas

    2015-01-01

    Ebstein's anomaly is a congenital disorder characterized by apical displacement of the septal leaflet of the tricuspid valve. Ebstein's anomaly may be seen in association with other cardiac conditions, including patent foramen ovale, atrial septal defect, and left ventricular noncompaction (LVNC). LVNC is characterized by increased trabeculation within the left ventricular apex. Echocardiography is often used to diagnose LVNC; however, magnetic resonance (MR) imaging offers superior characterization of the myocardium. We report a case of sudden cardiac death in a patient with Ebstein's anomaly with unrecognized LVNC noted on post mortem examination with screening documenting the presence of LVNC in one of the patient's twin sons. PMID:26240764

  14. Noncompaction of the Ventricular Myocardium and Polycystic Kidney Disease: A Case Report.

    PubMed

    Fukino, Keiko; Ishiwata, Junpei; Shinohara, Hiroki; Oshima, Tsukasa; Kozaki, Tsunashi; Ikutomi, Masayasu; Amaki, Toshihiro; Nakamura, Fumitaka

    2016-06-01

    Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary disorders, characterized by the formation of multiple cysts in the kidneys and other organs, as well as noncystic manifestations such as cerebral aneurysm. The most common cardiovascular disorders associated with ADPKD include valvular abnormalities and aortic aneurysm. An association between ADPKD and impaired left ventricular function has occasionally been reported. We describe a 74-year-old woman with ADPKD and exertional dyspnea. Impaired left ventricular function resulting from noncompaction of the ventricular myocardium (NVM) and secondary left ventricular aneurysm were diagnosed. Cardiac sarcoidosis and ischemic heart disease were ruled out. Myocardial ischemia resulting from NVM was the presumptive cause of the ventricular aneurysm. To our knowledge, this is the first report of concurrent isolated NVM and left ventricular aneurysm in a patient with ADPKD. ADPKD and various cardiomyopathies, including NVM, are all reported to involve mutations of sarcomere genes, suggesting a possible link between the conditions. PMID:26873255

  15. A rare form of cardiomyopathy: left ventricular non-compaction cardiomyopathy

    PubMed Central

    Goud, Aditya; Padmanabhan, Sriram

    2016-01-01

    Left ventricular non-compaction is a recently recognized, rare form of cardiomyopathy. It is based on the arrest of endomyocardial morphogenesis during embryogenesis. It was first described in 1984 by Engberding who described it as isolated ‘sinusoids’ within the LV. Right now its prevalence is estimated at 0.014 to 1.3 and 3–4% in heart failure patients. Its clinical manifestations are highly variable, ranging from no symptoms to disabling congestive heart failure, arrhythmias, and systemic thromboemboli. Doppler Echocardiogram is considered the diagnostic procedure of choice and treatment is symptomatic management of its symptoms and complications. PMID:26908378

  16. Postnatal Outcome of Fetal Left Ventricular Hypertrabeculation/Noncompaction.

    PubMed

    Stöllberger, Claudia; Wegner, Christian; Benatar, Abraham; Chin, Thomas K; Dangel, Joanna; Majoor-Krakauer, Danielle; Mondal, Tapas K; Sivanandam, Shanthi; Silverman, Norman H; van Waning, Jaap; Finsterer, Josef

    2016-06-01

    Left ventricular hypertrabeculation/noncompaction (LVHT) is a cardiac abnormality of unknown etiology. Prenatal diagnosis of LVHT can be established by fetal echocardiography. A review of 106 published cases showed that 46 cases with prenatally diagnosed LVHT were alive 0.5-120 months after birth. Since the course of cases with prenatally LVHT after publication is unknown, we aimed to collect follow-up-information. Information regarding vital status, cardiac and extracardiac morbidity was gathered by contacting the authors of the 46 cases. Fourteen of the 28 authors answered and gave information about 18 cases (six females, seven males, five gender-unknown, age 18 months to 10 years, mean follow-up 60 months). No differences were found between the 18 cases with follow-up and the 28 cases without follow-up regarding age, gender, cardiac or extracardiac comorbidities, and interventions. Three of the 18 cases had died subsequently from heart failure, osteosarcoma, and enterocolitis, respectively. Mutations or chromosomal abnormalities were found in six of the seven examined patients, extracardiac abnormalities in nine patients. Three patients received a pacemaker because of complete AV block, and two patients underwent heart transplantation. Cardiac surgical or interventional procedures were carried out in four patients. None suffered from malignant arrhythmias or had a cardioverter-defibrillator implanted. Based on the limited information, there are indications that cases with fetal diagnosis of LVHT have a continuing morbidity and mortality, even if they receive appropriate care. Since fetal LVHT is frequently associated with genetic abnormalities, further research about survival and underlying genetic causes is needed. PMID:27033242

  17. Left ventricular noncompaction (LVNC) and low mitochondrial membrane potential are specific for Barth syndrome.

    PubMed

    Karkucinska-Wieckowska, Agnieszka; Trubicka, Joanna; Werner, Bozena; Kokoszynska, Katarzyna; Pajdowska, Magdalena; Pronicki, Maciej; Czarnowska, Elzbieta; Lebiedzinska, Magdalena; Sykut-Cegielska, Jolanta; Ziolkowska, Lidia; Jaron, Weronika; Dobrzanska, Anna; Ciara, Elzbieta; Wieckowski, Mariusz R; Pronicka, Ewa

    2013-11-01

    Barth syndrome (BTHS) is an X-linked mitochondrial defect characterised by dilated cardiomyopathy, neutropaenia and 3-methylglutaconic aciduria (3-MGCA). We report on two affected brothers with c.646G > A (p.G216R) TAZ gene mutations. The pathogenicity of the mutation, as indicated by the structure-based functional analyses, was further confirmed by abnormal monolysocardiolipin/cardiolipin ratio in dry blood spots of the patients as well as the occurrence of this mutation in another reported BTHS proband. In both brothers, 2D-echocardiography revealed some features of left ventricular noncompaction (LVNC) despite marked differences in the course of the disease; the eldest child presented with isolated cardiomyopathy from late infancy, whereas the youngest showed severe lactic acidosis without 3-MGCA during the neonatal period. An examination of the patients' fibroblast cultures revealed that extremely low mitochondrial membrane potentials (mtΔΨ about 50 % of the control value) dominated other unspecific mitochondrial changes detected (respiratory chain dysfunction, abnormal ROS production and depressed antioxidant defense). 1) Our studies confirm generalised mitochondrial dysfunction in the skeletal muscle and the fibroblasts of BTHS patients, especially a severe impairment in the mtΔΨ and the inhibition of complex V activity. It can be hypothesised that impaired mtΔΨ and mitochondrial ATP synthase activity may contribute to episodes of cardiac arrhythmia that occurred unexpectedly in BTHS patients. 2) Severe lactic acidosis without 3-methylglutaconic aciduria in male neonates as well as an asymptomatic mild left ventricular noncompaction may characterise the ranges of natural history of Barth syndrome. PMID:23361305

  18. Purkinje fiber dysplasia (histiocytoid cardiomyopathy) with ventricular noncompaction in a savannah kitten.

    PubMed

    Gelberg, H B

    2009-07-01

    In a 2-month-old female savannah kitten that died unexpectedly, the pathologic findings of significance were restricted to the heart and included abnormal Purkinje fibers and biventricular myocardial trabeculation or noncompaction. The Purkinje fibers were large, angular, and tightly packed. They contained few disorganized myofibrils among a rarified cytoplasm. The fibers were distinct from adjacent myocytes and were immunohistochemically positive for desmin, muscle actin, myoglobin, sarcomeric actin, and chromogranin A. These findings are identical to those that occur in children with histiocytoid cardiomyopathy, a fatal genetic mitochondrial disorder of Purkinje fibers. Ventricular noncompaction likely has a multifactoral cause that results from fetal arrest of ventricular organizational development that might occur in conjunction with, or independent of, histiocytoid cardiomyopathy. PMID:19276060

  19. Successful staged Fontan completion for a tricuspid atresia patient with left ventricular non-compaction.

    PubMed

    Shimada, Masatoshi; Sakamoto, Takahiko; Umezu, Kentaro; Harada, Yorikazu

    2016-03-01

    We report a case of Fontan completion for a tricuspid atresia (TA) patient with left ventricular non-compaction (LVNC). The patient was diagnosed with TA (Ia) with LVNC by fetal echocardiography. Because the unfavourable prognosis of LVNC was anticipated, Imidapril as well as Carvedilol were administered to improve cardiac function, from the early stages of infancy. Staged Fontan completion with fenestration was successfully achieved with improvement of LV function. PMID:26689445

  20. Left Ventricular Noncompaction Combined With Epinephrine-Secreted Pheochromocytoma Inducing Heart Failure.

    PubMed

    Han, Ling; Luo, Jing-Gang; Chen, Xin; Hu, Wen-Ze; Chen, Li-Wei; Xin, Xiao-Ming; Yang, Ming; Duan, Jun; Zou, Feng-Jun; Teng, Xu; Qi, Yong-Fen

    2016-03-22

    Pheochromocytomas and left ventricular noncompaction (LVNC) are both rare diseases. In this patient, the long duration of the catecholamine-secreted pheochromocytoma caused myocardial ischemia, pressure overload, and hypertrophy, resulting in the onset of heart failure (HF). The LVNC might be associated with the acute attack of HF induced by the pheochromocytoma. This is the first case reporting LVNC in combination with HF secondary to pheochromocytoma. PMID:26973259

  1. [Perioperative Management of Emergency Gastrointestinal Surgery in a Patient with Left Ventricular Non-compaction].

    PubMed

    Kurazumi, Takuya; Suzuki, Takeshi; Ideno, Satoshi; Sakuma, Takahiro; Nagafuchi, Mari; Sato, Tomoyuki; Oshida, Junya

    2015-02-01

    Left ventricular non-compaction (LVNC) is a rare congenital cardiomyopathy characterized by heart failure, arrhythmia, and embolic events. A 65-year-old man, previously diagnosed as LVNC, was admitted to the emergency department with severe abdominal pain. He was diagnosed as appendicitis and treated conservatively with antibiotics. The echocardiogram examination showed left ventricular ejection fraction of less than 25%, and his B-type natriuretic peptide assay was > 5,000 pg x ml(-1) on admission. Ten days after admission, he underwent emergency surgery for suspected perforation of vermiform appendix. Transesophageal echocardiography (TEE) was used for real-time evaluation of cardiac function and restrictive fluid management during surgery. He was transferred to intensive care unit (ICU) for postoperative care, and extubated 16 hours after surgery. On the third postoperative day, he was discharged from ICU without any complications. We consider that perioperative hemodynamic management with TEE may be useful for gastrointestinal tract surgeries in patients with severe cardiac disease, such as LVNC. PMID:26121812

  2. Loss of Function Mutations in NNT Are Associated with Left Ventricular Noncompaction

    PubMed Central

    Bainbridge, Matthew N.; Davis, Erica E.; Choi, Wen-Yee; Dickson, Amy; Martinez, Hugo R.; Wang, Min; Dinh, Huyen; Muzny, Donna; Pignatelli, Ricardo; Katsanis, Nicholas; Boerwinkle, Eric; Gibbs, Richard; Jefferies, John L.

    2015-01-01

    Background Left ventricular noncompaction (LVNC) is an autosomal dominant, genetically heterogeneous cardiomyopathy with variable severity, which may co-occur with cardiac hypertrophy. Methods and Results Here, we generated whole exome sequence (WES) data from multiple members from five families with LVNC. In four out of five families, the candidate causative mutation segregates with disease in known LVNC genes MYH7 and TPM1. Subsequent sequencing of MYH7 in a larger LVNC cohort identified seven novel likely disease causing variants. In the fifth family, we identified a frameshift mutation in NNT, a nuclear encoded mitochondrial protein, not implicated previously in human cardiomyopathies. Resequencing of NNT in additional LVNC families identified a second likely pathogenic missense allele. Suppression of nnt in zebrafish caused early ventricular malformation and contractility defects, likely driven by altered cardiomyocyte proliferation. In vivo complementation studies showed that mutant human NNT failed to rescue nnt morpholino-induced heart dysfunction, indicating a probable haploinsufficiency mechanism. Conclusions Together, our data expand the genetic spectrum of LVNC and demonstrate how the intersection of WES with in vivo functional studies can accelerate the identification of genes that drive human genetic disorders. PMID:26025024

  3. LVAD as a Bridge to Heart Transplantation in a Patient with Left Ventricular Noncompaction Cardiomyopathy and Advanced Heart Failure.

    PubMed

    Cerar, Andraž; Kšela, Juš; Poglajen, Gregor; Vrtovec, Bojan; Kneževič, Ivan

    2016-01-01

    Left ventricular noncompaction cardiomyopathy (LVNC) is a rare hereditary cardiomyopathy characterized by the formation of an outer compacted and inner noncompacted layer of the myocardium. The latter is characterized by prominent trabeculations and deep intertrabecular recesses and is functionally inferior to the compacted myocardium. As there is no specific treatment for patients with LVNC who develop heart failure, the management of these patients is limited and many patients progress to advanced stages of the disease. For LVNC patients with advanced heart failure, the data regarding the use of mechanical circulatory support are scarce. We report a case of a 29-year-old patient with LVNC and advanced refractory heart failure, who was successfully bridged to heart transplantation using a long-term continuous-flow left ventricular assist device. PMID:27355148

  4. A Rare Association of Non-Compaction of the Ventricular Myocardium, and Non-Immune Hydrops Fetalis.

    PubMed

    Nandyal, Raja; Moorthy, Ganga

    2016-01-01

    Hydrops fetalis is a rare manifestation of severe congestive heart failure in a fetus, resulting in pathological fluid accumulation in fetal soft tissues and/or serous cavities. Non-compaction of the ventricular myocardium, frequently referred to as the left ventricular non-compaction (LVNC), is a very rare congenital cardiomyopathy. For LVNC, echocardiography is the diagnostic modality of choice. Various diagnostic criteria exist based on either echocardiography or MRI. Currently, nonimmune hydrops fetalis (NIHF) comprise almost 90% of all hydrops fetalis cases. Among cardiovascular conditions that contribute to NIHF (20%), structural malformations (especially hypoplastic left heart, endocardial cushion defect) and arrhythmias are the most frequent etiological factors. We describe an extremely preterm neonate who presented with features of non-Immune hydrops fetalis (NIHF) associated with LVNC and profound refractory systemic hypotension. PMID:27328555

  5. Effects of β-blocker therapy on electrocardiographic and echocardiographic characteristics of left ventricular noncompaction.

    PubMed

    Li, Jin; Franke, Jennifer; Pribe-Wolferts, Regina; Meder, Benjamin; Ehlermann, Philipp; Mereles, Derliz; Andre, Florian; Abdelrazek, Mohamed Assem; Merten, Constanze; Schweizer, Patrick A; Becker, Rüdiger; Katus, Hugo A; Thomas, Dierk

    2015-03-01

    Left ventricular noncompaction (LVNC) is a cardiomyopathy with hypertrabeculation of the LV, often complicated by heart failure, arrhythmia and thromboembolic events. The features of LVNC are still incompletely characterized due to its late recognition as clinically relevant condition. The aims of this study were to describe echocardiographic and electrophysiologic characteristics of LVNC patients and to assess the effects of chronic β-blocker treatment. Study patients (n = 20; 42.5 [36.3; 52.5] years; 12 men) exhibited reduced LV ejection fraction (median LVEF = 32 %) and an increased LV mass of 210 g. Sinus rhythm was present in 19 patients, whereas one patient was in atrial fibrillation. Baseline heart rate was 77.5 beats per minute. Left bundle branch block was detected in five cases. In a subgroup of patients receiving β-blocker therapy (n = 17), LV mass was reduced from 226 [178; 306] g to 220 [169; 254] g (p = 0.007) at 13 ± 6 months follow-up. By contrast, a subgroup of three patients that were not treated with an anti-β-adrenergic agent showed LV mass increase from 180 [169; 197] g to 199 [185; 213] g (p = 0.023). LVEF and electrocardiographic parameters were not significantly modulated during chronic β-blocker treatment. There was no sustained symptomatic ventricular tachyarrhythmia, thromboembolic event or death in either group. In conclusion, this study reveals reduction of LV mass among LVNC patients during β-blocker therapy. Effects of β-blocker treatment in LVNC require validation in prospective controlled studies. PMID:25331160

  6. Noncompaction of the Ventricular Myocardium Is Associated with a De Novo Mutation in the β-Myosin Heavy Chain Gene

    PubMed Central

    Budde, Birgit S.; Binner, Priska; Waldmüller, Stephan; Höhne, Wolfgang; Blankenfeldt, Wulf; Hassfeld, Sabine; Brömsen, Jürgen; Dermintzoglou, Anastassia; Wieczorek, Marcus; May, Erik; Kirst, Elisabeth; Selignow, Carmen; Rackebrandt, Kirsten; Müller, Melanie; Goody, Roger S.; Vosberg, Hans-Peter; Nürnberg, Peter; Scheffold, Thomas

    2007-01-01

    Noncompaction of the ventricular myocardium (NVM) is the morphological hallmark of a rare familial or sporadic unclassified heart disease of heterogeneous origin. NVM results presumably from a congenital developmental error and has been traced back to single point mutations in various genes. The objective of this study was to determine the underlying genetic defect in a large German family suffering from NVM. Twenty four family members were clinically assessed using advanced imaging techniques. For molecular characterization, a genome-wide linkage analysis was undertaken and the disease locus was mapped to chromosome 14ptel-14q12. Subsequently, two genes of the disease interval, MYH6 and MYH7 (encoding the α- and β-myosin heavy chain, respectively) were sequenced, leading to the identification of a previously unknown de novo missense mutation, c.842G>C, in the gene MYH7. The mutation affects a highly conserved amino acid in the myosin subfragment-1 (R281T). In silico simulations suggest that the mutation R281T prevents the formation of a salt bridge between residues R281 and D325, thereby destabilizing the myosin head. The mutation was exclusively present in morphologically affected family members. A few members of the family displayed NVM in combination with other heart defects, such as dislocation of the tricuspid valve (Ebstein's anomaly, EA) and atrial septal defect (ASD). A high degree of clinical variability was observed, ranging from the absence of symptoms in childhood to cardiac death in the third decade of life. The data presented in this report provide first evidence that a mutation in a sarcomeric protein can cause noncompaction of the ventricular myocardium. PMID:18159245

  7. PLEKHM2 mutation leads to abnormal localization of lysosomes, impaired autophagy flux and associates with recessive dilated cardiomyopathy and left ventricular noncompaction.

    PubMed

    Muhammad, Emad; Levitas, Aviva; Singh, Sonia R; Braiman, Alex; Ofir, Rivka; Etzion, Sharon; Sheffield, Val C; Etzion, Yoram; Carrier, Lucie; Parvari, Ruti

    2015-12-20

    Gene mutations, mostly segregating with a dominant mode of inheritance, are important causes of dilated cardiomyopathy (DCM), a disease characterized by enlarged ventricular dimensions, impaired cardiac function, heart failure and high risk of death. Another myocardial abnormality often linked to gene mutations is left ventricular noncompaction (LVNC) characterized by a typical diffuse spongy appearance of the left ventricle. Here, we describe a large Bedouin family presenting with a severe recessive DCM and LVNC. Homozygosity mapping and exome sequencing identified a single gene variant that segregated as expected and was neither reported in databases nor in Bedouin population controls. The PLEKHM2 cDNA2156_2157delAG variant causes the frameshift p.Lys645AlafsTer12 and/or the skipping of exon 11 that results in deletion of 30 highly conserved amino acids. PLEKHM2 is known to interact with several Rabs and with kinesin-1, affecting endosomal trafficking. Accordingly, patients' primary fibroblasts exhibited abnormal subcellular distribution of endosomes marked by Rab5, Rab7 and Rab9, as well as the Golgi apparatus. In addition, lysosomes appeared to be concentrated in the perinuclear region, and autophagy flux was impaired. Transfection of wild-type PLEKHM2 cDNA into patient's fibroblasts corrected the subcellular distribution of the lysosomes, supporting the causal effect of PLEKHM2 mutation. PLEKHM2 joins LAMP-2 and BAG3 as a disease gene altering autophagy resulting in an isolated cardiac phenotype. The association of PLEKHM2 mutation with DCM and LVNC supports the importance of autophagy for normal cardiac function. PMID:26464484

  8. Biventricular non-compaction with predominant right ventricular involvement, reduced left ventricular systolic and diastolic function, and pulmonary hypertension in a Hispanic male

    PubMed Central

    Said, Sarmad; Cooper, Chad J.; Quevedo, Karla; Rodriguez, Emmanuel; Hernandez, German T.

    2013-01-01

    Patient: Male, 22 Final Diagnosis: Cardiomyopathy Symptoms: Shortness of breath • dispnoea • chest discomfort Medication: — Clinical Procedure: Echocardiogram • cardiac MRI Specialty: Cardiology Objective: Challenging differential diagnosis Background: Non-compaction cardiomyopathy (NCM) is a rare congenital cardiomyopathy characterized by increased trabeculation in one or more segments of the ventricle. The left ventricle is most commonly affected. However, biventricular involvement or right ventricle predominance has also been described. Clinical features of NCM are non-specific and can range from being asymptomatic to symptoms of congestive heart failure, arrhythmia, and systemic thromboembolism. Case Report: 22-year-old Hispanic male presented with two month history of chest discomfort. Laboratory workup revealed an elevated brain-natriuretic-peptide of 1768 pg/ml. ECG and chest x-ray was nonspecific. Transthoracic echocardiogram revealed prominent trabeculae and spongiform appearance of the left ventricle (LV) with an ejection-fraction of 15–20%; 5 of 9 segments of the LV were trabeculated with deep intertrabecular recesses also involving the right ventricle (RV) with demonstrated blood flow in these recesses on color-doppler. The biventricular spongiform appearance was morphologically suggestive for NCM with involvement of the RV. Confirmatory cardiac MRI was performed, demonstrating excessive trabeculation of the left-ventricular apex and mid-ventricular segments. Hypertrabecularion was exhibited at the apical and lateral wall of the RV. Cardiac catheterization showed an intact cardiac vessel system. The patient was discharged on heart failure treatment and was placed on the heart transplantation list. Conclusions: NCM is a unique disorder resulting in serious and severe complications. The majority of the reported cases describe the involvement of the left ventricle. However, the right ventricle should be taken into careful consideration. The early

  9. Monoamniotic monochorionic twins discordant for noncompaction cardiomyopathy.

    PubMed

    Ng, Dianna; Bouhlal, Yosr; Ursell, Philip C; Shieh, Joseph T C

    2013-06-01

    Occasionally "identical twins" are phenotypically different, raising the question of zygosity and the issue of genetic versus environmental influences during development. We recently noted monochorionic-monoamniotic twins, one of which had an isolated cardiac abnormality, noncompaction cardiomyopathy, a condition characterized by cardiac ventricular hypertrabeculation. We examined the prenatal course and subsequent pathologic correlation since ventricular morphogenesis may depend on early muscular contraction and blood flow. The monochorionic-monoamniotic female twin pair was initially identified since one fetus presented with increased nuchal translucency. Complete heart block was later identified in the fetus with nuchal translucency who did not survive after delivery. In contrast, the unaffected twin had normal cardiac studies both prenatally and postnatally. Pathologic analysis of the affected twin demonstrated noncompaction of the left ventricle with dysplasia of the aortic and pulmonary valves. Dissection of the cardiac conduction system disclosed atrioventricular bundle fibrosis. Maternal lupus studies, amniocentesis with karyotype, and studies for 22q11.2 were normal. To test for zygosity, we performed multiple STR marker analysis and found that all markers were shared even using nonblood tissues from the affected twin. These studies demonstrate that monozygotic twins that are monochorionic monoamniotic can be discordant for cardiac noncompaction. The results suggest further investigation into the potential roles of pathologic fibrosis, contractility, and blood flow in cardiac ventricle development. PMID:23636980

  10. Ebstein anomaly, left ventricular non-compaction, and early onset heart failure associated with a de novo α-tropomyosin gene mutation.

    PubMed

    Kelle, Angela M; Bentley, S Jared; Rohena, Luis O; Cabalka, Allison K; Olson, Timothy M

    2016-08-01

    Ebstein anomaly of the tricuspid valve (EA) can be associated with left ventricular non-compaction (LVNC), a rare congenital cardiomyopathy. We report a 2 year-old female with EA and severe tricuspid regurgitation, LVNC, pulmonary hypertension, and chronic biventricular systolic heart failure, who died during evaluation for cardiac transplantation. Gene panel testing revealed a heterozygous de novo missense mutation in TPM1, which encodes the cardiac sarcomeric thin filament protein α-tropomyosin. The c.475G>A variant results in a p.Asp159Asn substitution, altering a highly conserved residue predicted to be damaging to protein structure and function. TPM1 is the second gene linked to EA with LVNC in humans, implicating overlap in the molecular basis of structural and myopathic heart disease. © 2016 Wiley Periodicals, Inc. PMID:27177193

  11. Next-generation sequencing (NGS) as a fast molecular diagnosis tool for left ventricular noncompaction in an infant with compound mutations in the MYBPC3 gene.

    PubMed

    Schaefer, Elise; Helms, Pauline; Marcellin, Luc; Desprez, Philippe; Billaud, Philippe; Chanavat, Valérie; Rousson, Robert; Millat, Gilles

    2014-03-01

    Left ventricular noncompaction (LVNC) is a clinically heterogeneous disorder characterized by a trabecular meshwork and deep intertrabecular myocardial recesses that communicate with the left ventricular cavity. LVNC is classified as a rare genetic cardiomyopathy. Molecular diagnosis is a challenge for the medical community as the condition shares morphologic features of hypertrophic and dilated cardiomyopathies. Several genetic causes of LVNC have been reported, with variable modes of inheritance, including autosomal dominant and X-linked inheritance, but relatively few responsible genes have been identified. In this report, we describe a case of a severe form of LVNC leading to death at 6 months of life. NGS sequencing using a custom design for hypertrophic cardiomyopathy panel allowed us to identify compound heterozygosity in the MYBPC3 gene (p.Lys505del, p.Pro955fs) in 3 days, confirming NGS sequencing as a fast molecular diagnosis tool. Other studies have reported neonatal presentation of cardiomyopathies associated with compound heterozygous or homozygous MYBPC3 mutations. In this family and in families in which parental truncating MYBPC3 mutations are identified, preimplantation or prenatal genetic screening should be considered as these genotypes leads to neonatal mortality and morbidity. PMID:24602869

  12. Myocardial Noncompaction Presenting With Myocardial Bridge

    PubMed Central

    Shen, Yuechun; Li, Xinchun; Lu, Dongfeng; Xiao, Aiyi; Li, Jun

    2015-01-01

    Abstract Myocardial noncompaction, namly isolated noncompaction of the left ventricular myocardium (NVM), is a rare congenital disease. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects, mostly stenotic lesions of the left ventricular outflow tract. A myocardial bridge (MB) is thought being associated with coronary heart disease, such as coronary spasm, arrhythmia, and so on. The significance of MB in association with other congenital cardiac conditions is unknown. We report a novel case who was presented NVM and MB. A 34-year-old man complained of chest prickling-like pain and dizzy for 1 year. His blood pressure was 110/70 mm Hg. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV); deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall; and LV ejection fraction of 57%. A coronary computerized tomography scan showed that part, 38.9 cm, of left descending artery tunnel was surrounding by cardiac muscles rather than resting on top of the myocardium. The therapeutics interventions included lifestyle cares, agents of anti-ischemia and improvement myocardial cell metabolism. The patient was followed up for 2.6 years, and his general condition was stable. This case indicates that NVM can be developed with MB, and the complete diagnosis of NVM and MB should be made by different image studies. PMID:26356695

  13. A mouse model of human congenital heart disease: high incidence of diverse cardiac anomalies and ventricular noncompaction produced by heterozygous Nkx2-5 homeodomain missense mutation

    PubMed Central

    Chang, Eileen I.; Terada, Ryota; Ryan, Nicole J.; Briggs, Laura E.; Chowdhury, Rajib; Zárate, Miguel A.; Sugi, Yukiko; Nam, Hyun-Joo; Benson, D. Woodrow; Anderson, Robert H.; Kasahara, Hideko

    2014-01-01

    Background Heterozygous human mutations of NKX2-5 are highly penetrant and associated with varied congenital heart defects. The heterozygous knockout of murine Nkx2-5, in contrast, manifests less profound cardiac malformations, with low disease penetrance. We sought to study this apparent discrepancy between human and mouse genetics. Since missense mutations in the NKX2-5 homeodomain (DNA binding domain) are the most frequently reported type of human mutation, we replicated this genetic defect in a murine knock-in model. Methods and Results We generated a murine model in a 129/Sv genetic background by knocking-in an Nkx2-5 homeodomain missense mutation previously identified in humans. The mutation was located at homeodomain position 52Arg→Gly (R52G). All the heterozygous neonatal Nkx2-5+/R52G mice demonstrated a prominent trabecular layer in the ventricular wall, so called noncompaction, along with diverse cardiac anomalies, including atrioventricular septal defects, Ebstein’s malformation of the tricuspid valve, and perimembranous and/or muscular ventricular septal defects. In addition, P10 Nkx2-5+/R52G mice demonstrated atrial septal anomalies, with significant increase in the size of the inter-atrial communication and fossa ovalis, and decrease in the length of the flap valve compared to control Nkx2-5+/+ or Nkx2-5+/− mice. Conclusion The results of our study demonstrate that heterozygous missense mutation in the murine Nkx2-5 homeodomain (R52G) are highly penetrant, and result in pleiotropic cardiac effects. Thus, in contrast to heterozygous Nkx2-5 knockout mice, the effects of the heterozygous knock-in mimic findings in humans with heterozygous missense mutation in NKX2-5 homeodomain. PMID:25028484

  14. Arrhythmogenic Noncompaction Cardiomyopathy: Is There an Echocardiographic Phenotypic Overlap of Two Distinct Cardiomyopathies?

    PubMed Central

    Aras, Dursun; Cay, Serkan; Ozcan, Firat; Baser, Kazım; Dogan, Umuttan; Unlu, Murat; Demirkan, Burcu; Tufekcioglu, Omac; Topaloglu, Serkan

    2015-01-01

    The clinical diagnosis of right ventricular (RV) cardiomyopathies is often challenging. It is difficult to differentiate the isolated left ventricular (LV) noncompaction cardiomyopathy (NC) from biventricular NC or from coexisting arrhythmogenic ventricular cardiomyopathy (AC). There are currently few established morphologic criteria for the diagnosis other than RV dilation and presence of excessive regional trabeculation. The gross and microscopic changes suggest pathological similarities between, or coexistence of, RV-NC and AC. Therefore, the term arrhythmogenic right ventricular cardiomyopathy is somewhat misleading as isolated LV or biventricular involvement may be present and thus a broader term such as AC should be preferred. We describe an unusual case of AC associated with a NC in a 27-year-old man who had a history of permanent pacemaker 7 years ago due to second-degree atrioventricular block. PMID:26448828

  15. Isolated right ventricular infarction: a diagnostic challenge.

    PubMed

    Vieira, Catarina; Santa Cruz, Andre; Arantes, Carina; Rocha, Sérgia

    2016-01-01

    A 73-year-old woman was admitted to the emergency room due to sudden-onset dyspnoea, altered mental status and haemodynamic instability. ECG showed a junctional rhythm, T-wave inversion in I, aVL and V2-V6 (present in a previous ECG), and no ST/T changes in the right precordial leads. Transthoracic echocardiography, however, revealed a severe depression of global systolic function of right ventricle with akinesia of free wall and a normal left ventricular function. Coronary angiography showed an occlusion of the proximal segment of the right coronary artery, which was treated with balloon angioplasty, and a chronic lesion of the anterior descending artery. The patient had a good recovery and was discharged on the 14th day. Myocardial perfusion scintigraphy (stress and rest) was performed a month later, showing a fixed perfusion defect in the apex and anterior wall (medium-apical), with no signs of ischaemia. PMID:27143166

  16. A Rare Case of Renal Infarct due to Noncompaction Cardiomyopathy: A Case Report and Literature Review

    PubMed Central

    Chen, On; Uppal, Nupur Nippun; Batul, Syeda Atiqa; Moskovits, Norbert; Shetty, Vijay; Shani, Jacob

    2016-01-01

    Left ventricular noncompaction cardiomyopathy is a rare myocardial disorder which results from failure of left ventricle to compact in embryogenesis. We present a case of a 53-year-old female who came because of abdominal pain and was found to have renal infarct secondary to noncompaction cardiomyopathy. PMID:27022488

  17. Common arterial trunk and ventricular non-compaction in Lrp2 knockout mice indicate a crucial role of LRP2 in cardiac development.

    PubMed

    Baardman, Maria E; Zwier, Mathijs V; Wisse, Lambertus J; Gittenberger-de Groot, Adriana C; Kerstjens-Frederikse, Wilhelmina S; Hofstra, Robert M W; Jurdzinski, Angelika; Hierck, Beerend P; Jongbloed, Monique R M; Berger, Rolf M F; Plösch, Torsten; DeRuiter, Marco C

    2016-04-01

    Lipoprotein-related receptor protein 2 (LRP2) is important for development of the embryonic neural crest and brain in both mice and humans. Although a role in cardiovascular development can be expected, the hearts ofLrp2knockout (KO) mice have not yet been investigated. We studied the cardiovascular development ofLrp2KO mice between embryonic day 10.5 (E10.5) and E15.5, applying morphometry and immunohistochemistry, using antibodies against Tfap2α (neural crest cells), Nkx2.5 (second heart field), WT1 (epicardium derived cells), tropomyosin (myocardium) and LRP2. TheLrp2KO mice display a range of severe cardiovascular abnormalities, including aortic arch anomalies, common arterial trunk (persistent truncus arteriosus) with coronary artery anomalies, ventricular septal defects, overriding of the tricuspid valve and marked thinning of the ventricular myocardium. Both the neural crest cells and second heart field, which are essential for the lengthening and growth of the right ventricular outflow tract, are abnormally positioned in theLrp2KO. This explains the absence of the aorto-pulmonary septum, which leads to common arterial trunk and ventricular septal defects. Severe blebbing of the epicardial cells covering the ventricles is seen. Epithelial-mesenchymal transition does occur; however, there are fewer WT1-positive epicardium-derived cells in the ventricular wall as compared to normal, coinciding with the myocardial thinning and deep intertrabecular spaces. LRP2 plays a crucial role in cardiovascular development in mice. This corroborates findings of cardiac anomalies in humans withLRP2mutations. Future studies should reveal the underlying signaling mechanisms in which LRP2 is involved during cardiogenesis. PMID:26822476

  18. Common arterial trunk and ventricular non-compaction in Lrp2 knockout mice indicate a crucial role of LRP2 in cardiac development

    PubMed Central

    Baardman, Maria E.; Zwier, Mathijs V.; Wisse, Lambertus J.; Gittenberger-de Groot, Adriana C.; Kerstjens-Frederikse, Wilhelmina S.; Hofstra, Robert M. W.; Jurdzinski, Angelika; Hierck, Beerend P.; Jongbloed, Monique R. M.; Berger, Rolf M. F.; Plösch, Torsten; DeRuiter, Marco C.

    2016-01-01

    ABSTRACT Lipoprotein-related receptor protein 2 (LRP2) is important for development of the embryonic neural crest and brain in both mice and humans. Although a role in cardiovascular development can be expected, the hearts of Lrp2 knockout (KO) mice have not yet been investigated. We studied the cardiovascular development of Lrp2 KO mice between embryonic day 10.5 (E10.5) and E15.5, applying morphometry and immunohistochemistry, using antibodies against Tfap2α (neural crest cells), Nkx2.5 (second heart field), WT1 (epicardium derived cells), tropomyosin (myocardium) and LRP2. The Lrp2 KO mice display a range of severe cardiovascular abnormalities, including aortic arch anomalies, common arterial trunk (persistent truncus arteriosus) with coronary artery anomalies, ventricular septal defects, overriding of the tricuspid valve and marked thinning of the ventricular myocardium. Both the neural crest cells and second heart field, which are essential for the lengthening and growth of the right ventricular outflow tract, are abnormally positioned in the Lrp2 KO. This explains the absence of the aorto-pulmonary septum, which leads to common arterial trunk and ventricular septal defects. Severe blebbing of the epicardial cells covering the ventricles is seen. Epithelial-mesenchymal transition does occur; however, there are fewer WT1-positive epicardium-derived cells in the ventricular wall as compared to normal, coinciding with the myocardial thinning and deep intertrabecular spaces. LRP2 plays a crucial role in cardiovascular development in mice. This corroborates findings of cardiac anomalies in humans with LRP2 mutations. Future studies should reveal the underlying signaling mechanisms in which LRP2 is involved during cardiogenesis. PMID:26822476

  19. Dual Endothelin Receptor Blockade Abrogates Right Ventricular Remodeling and Biventricular Fibrosis in Isolated Elevated Right Ventricular Afterload

    PubMed Central

    Nielsen, Eva Amalie; Sun, Mei; Honjo, Osami; Hjortdal, Vibeke E.; Redington, Andrew N.; Friedberg, Mark K.

    2016-01-01

    Background Pulmonary arterial hypertension is usually fatal due to right ventricular failure and is frequently associated with co-existing left ventricular dysfunction. Endothelin-1 is a powerful pro-fibrotic mediator and vasoconstrictor that is elevated in pulmonary arterial hypertension. Endothelin receptor blockers are commonly used as pulmonary vasodilators, however their effect on biventricular injury, remodeling and function, despite elevated isolated right ventricular afterload is unknown. Methods Elevated right ventricular afterload was induced by progressive pulmonary artery banding. Seven rabbits underwent pulmonary artery banding without macitentan; 13 received pulmonary artery banding + macitentan; and 5 did not undergo inflation of the pulmonary artery band (sham-operated controls). Results: Right and left ventricular collagen content was increased with pulmonary artery banding compared to sham-operated controls and ameliorated by macitentan. Right ventricular fibrosis signaling (connective tissue growth factor and endothelin-1 protein levels); extra-cellular matrix remodeling (matrix-metalloproteinases 2 and 9), apoptosis and apoptosis-related peptides (caspases 3 and 8) were increased with pulmonary artery banding compared with sham-operated controls and decreased with macitentan. Conclusion Isolated right ventricular afterload causes biventricular fibrosis, right ventricular apoptosis and extra cellular matrix remodeling, mediated by up-regulation of endothelin-1 and connective tissue growth factor signaling. These pathological changes are ameliorated by dual endothelin receptor blockade despite persistent elevated right ventricular afterload. PMID:26765263

  20. Noncompaction Cardiomyopathy: Case Presentation with Cardiac Magnetic Resonance Imaging Findings and Literature Review

    PubMed Central

    Saeedan, Mnahi Bin; Fathala, Ahmed L.; Mohammed, Tan-Lucien H.

    2015-01-01

    Left ventricular noncompaction cardiomyopathy is a very rare condition, yet believed to be often overlooked. It is thought to be caused by the developmental arrest in embryogenesis and characterized by an increase in the noncompacted, trabeculated myocardium adjacent to compacted myocardium in the left ventricular. The clinical presentations of this type of cardiomyopathy are of variable severity. Echocardiography used to be the diagnostic modality, but recent reports suggest that cardiac magnetic resonance imaging has higher sensitivity and specificity by showing a ratio of the noncompacted myocardium to compacted myocardium of >2.3. PMID:26900424

  1. An interesting case of cryptogenic stroke in a young man due to left ventricular non-compaction: role of cardiac MRI in the accurate diagnosis

    PubMed Central

    Kannan, Arun; Das, Anindita; Janardhanan, Rajesh

    2014-01-01

    A 28-year-old man arrived for an outpatient cardiac MRI (CMR) study to evaluate cardiac structure. At the age of 24 the patient presented with acute onset expressive aphasia and was diagnosed with ischaemic stroke. Echocardiography at that time was reported as ‘apical wall thickening consistent with apical hypertrophic cardiomyopathy’. CMR revealed a moderately dilated left ventricle with abnormal appearance of the left ventricular (LV) apical segments. Further evaluation was consistent with a diagnosis of LV non­compaction (LVNC) cardiomyopathy with a ratio of non­compacted to compacted myocardium measuring 3. There was extensive delayed hyperenhancement signal involving multiple segments representing a significant myocardial scar which is shown to have a prognostic role. Our patient, with no significant cerebrovascular risk factors, would likely have had an embolic stroke. This case demonstrates the role of CMR in accurately diagnosing LVNC in a patient with young stroke where prior echocardiography was non­diagnostic. PMID:24962593

  2. Isolated Left Ventricular Hypoplasia in a Postpartum Patient.

    PubMed

    Ding, Wern Yew; Meah, Mohammed; Rao, Archana; Fairbairn, Timothy; Hasleton, Jonathan

    2016-06-01

    A 22-year-old woman presented with lethargy and shortness of breath at 13 weeks postpartum. She was clinically tachypnoeic with signs of fluid overload. Telemetry revealed 2 different morphologies of nonsustained ventricular tachycardia, associated with chest discomfort. Cardiac imaging demonstrated a truncated, spherical left ventricle (LV) with severe systolic dysfunction and fatty replacement of the LV apex but no evidence of myocardial fibrosis. The right ventricle was elongated wrapping around the LV apex and had moderate systolic impairment. A diagnosis of "isolated LV apical hypoplasia" was made with possible concomitant peripartum cardiomyopathy. PMID:26706664

  3. Predicting self-terminating ventricular fibrillations in an isolated heart

    NASA Astrophysics Data System (ADS)

    Le, Duy-Manh; Dvornikov, Alexey V.; Lai, Pik-Yin; Chan, C. K.

    2013-11-01

    Ventricular fibrillations (VFs) in isolated hearts induced by fast pacing are studied in a Langendorff preparation by measuring the electrical signals from the right atrium (V_a) and the ventricle (V_v) . We find that when there is a strong component of Vv detected in Va during VF, the induced VFs are usually not self-terminating. Criteria for the prediction of self-terminating VFs are developed based on the analysis of Vv and Va by the cross-wavelet power spectrum and cross-Fourier power spectrum methods. The success rate of our prediction criteria is about 80-90 %. Our findings suggest that a heart under VF can recover its sinus rhythm only when the sino-atrial node of the heart is not under strong influence of the VF from its ventricle.

  4. Isolated Right Ventricular Dilated Cardiomyopathy: An Early Diagnosis

    PubMed Central

    Briongos Figuero, Sem; Acena Navarro, Alvaro

    2015-01-01

    Because of an incomplete right bundle branch block, a severe right ventricular dilatation with no left ventricular cardiomyopathy was found in a 44-year-old man. Magnetic resonance and transesophageal echocardiography confirmed the finding and these tests also failed to find any potential cause. A pulmonary hemodynamic study and a coronary angiography were strictly normal. Lastly pulmonary function tests and a pulmonary angiography were performed, which did not find any lung disease causing the right ventricular dilatation. The patient was catalogued as an early stage of an idiopathic form of right ventricular dilated cardiomyopathy. PMID:26346826

  5. Non-compaction cardiomyopathy in an asymptomatic athlete.

    PubMed

    Manus, Margaret Kapor; Roy, Satyajeet; Stag, Rosemarie; Hyman, Daniel

    2016-01-01

    Prevention of sudden cardiac death in athletes requires the screening and recognition of pathologies that often remain clinically silent for years until provoked by a physiologic stressor. This can result in the manifestation of disease and even death. Left ventricular non-compaction cardiomyopathy (LVNC), newly classified as a distinct entity arising in the adult population, is a cardiomyopathy that at initial presentation can manifest as a wide spectrum of symptoms from asymptomatic to ventricular arrhythmias, systemic embolism and even sudden cardiac death. We present the case of an asymptomatic athlete found to have LVNC and discuss the implications this finding may have on sports participation. PMID:27535732

  6. Isolated right ventricular cardiomyopathy with autoimmune hypothyroidism: a rare association in an adolescent.

    PubMed

    Yelve, Kavita; Panandikar, Gajanan Ashok; Pazare, Amar; Bajpai, Smrati

    2015-01-01

    A 13-year-old girl presented with progressive dyspnoea and palpitation, diagnosed on echocardiography as primary right ventricular cardiomyopathy with atrial fibrillation. Her thyroid profile was positive for antithyroid microsomal antibody, and antithyroid peroxidase antibodies were suggestive of autoimmune hypothyroidism. She was managed with furosemide, digoxin, acenocoumarol and thyroxine following which she showed significant improvement. This is a rare case of isolated right ventricular cardiomyopathy and its association with autoimmune hypothyroidism presenting at the age of 13. PMID:25795745

  7. Isolated acute occlusion of a large right ventricular branch of the right coronary artery following coronary balloon angioplasty. The only true 'model' to study ECG changes in acute, isolated right ventricular infarction.

    PubMed

    van der Bolt, C L; Vermeersch, P H; Plokker, H W

    1996-02-01

    An isolated right ventricular infarction occurs rarely and data on its electrocardiographic appearance and underlying angiographically proven cause are scarce. The electrocardiographic response of acute right ventricular ischaemia is often obscured by the coexisting forces of the ischaemic mass of the inferior wall of the left ventricle when the right coronary artery itself becomes occluded. Percutaneous transluminal coronary angioplasty of the right coronary artery may cause an isolated occlusion of a right ventricular branch. We encountered this phenomenon in nine patients. In all, it led to acute isolated right ventricular ischaemia with ST elevations in the right precordial leads (V1-V3, V3R and V4R) on the electrocardiogram. We conclude that the ECG pattern of pure right ventricular ischaemia can be seen when an isolated occlusion of a large right ventricular branch occurs, for example as a complication of percutaneous transluminal coronary angioplasty. PMID:8732378

  8. Surgical management of isolated multiple ventricular septal defects. Logical approach in 130 cases.

    PubMed

    Serraf, A; Lacour-Gayet, F; Bruniaux, J; Ouaknine, R; Losay, J; Petit, J; Binet, J P; Planché, C

    1992-03-01

    From January 1980 through September 1990, 130 children underwent surgical closure of isolated multiple ventricular septal defects (mean age 14 +/- 18 months, mean weight 7.0 +/- 4.4 kg). Sixty-one were less than 1 year of age. Sixty-one children had pulmonary protection, 51 had pulmonary artery banding, and 10 had pulmonary valve stenosis. All other patients had severe pulmonary hypertension (mean systolic pressure 75.7 +/- 20.5 mm Hg and already disabling heart failure (New York Heart Association classes III and IV). The surgical management was based on the location of the defects and the ventricular dominance that were assessed preoperatively and intraoperatively. Midtrabecular ventricular septal defects were always centered by the moderator band and were therefore divided into low trabecular, midtrabecular, and high trabecular defects. The perimembranous septum was involved in 102 patients, the trabecular in 121, the inlet septum in 12, and the infundibular septum in 9. Fifty patients had the "Swiss cheese" form of the lesion. Closure of the ventricular septal defects included Dacron patch and mattress sutures. They were always first approached through a right atriotomy, which was sufficient for complete repair in 82 patients. In midtrabecular ventricular septal defects, section of the moderator band (n = 24) allowed closure of all the defects with a single Dacron patch. In 48 patients a right atriotomy and a right (n = 32) or left (n = 14) (particularly for low trabecular ventricular septal defects) or both right and left (n = 2) ventriculotomies were necessary to secure the repair. The hospital mortality rate was 7.7% (10 patients). The causes of deaths were residual ventricular septal defect (n = 5), pulmonary hypertension (n = 2), hypoplastic right ventricle (n = 1) and left ventricle (n = 1), and myocardial infarction (n = 1). Among eighteen survivors with residual ventricular septal defect, six were reoperated on; there were two deaths. A permanent

  9. Calcium current in isolated neonatal rat ventricular myocytes.

    PubMed Central

    Cohen, N M; Lederer, W J

    1987-01-01

    1. Calcium currents (ICa) from neonatal rat ventricular heart muscle cells grown in primary culture were examined using the 'whole-cell' voltage-clamp technique (Hamill, Marty, Neher, Sakmann & Sigworth, 1981). Examination of ICa was limited to one calcium channel type, 'L' type (Nilius, Hess, Lansman & Tsien, 1985), by appropriate voltage protocols. 2. We measured transient and steady-state components of ICa, and could generally describe ICa in terms of the steady-state activation (d infinity) and inactivation (f infinity) parameters. 3. We observed that the reduction of ICa by the calcium channel antagonist D600 can be explained by both a shift of d infinity to more positive potentials as well as a slight reduction of ICa conductance. D600 did not significantly alter either the rate of inactivation of ICa or the voltage dependence of f infinity. 4. The calcium channel modulator BAY K8644 shifted both d infinity and f infinity to more negative potentials. Additionally, BAY K8644 increased the rate of inactivation at potentials between +5 and +55 mV. Furthermore, BAY K8644 also increased ICa conductance, a change consistent with a promotion of 'mode 2' calcium channel activity (Hess, Lansman & Tsien, 1984). 5. We conclude that, as predicted by d infinity and f infinity, there is a significant steady-state component of ICa ('window current') at plateau potentials in neonatal rat heart cells. Modulation of the steady-state and transient components of ICa by various agents can be attributed both to specific alterations in d infinity and f infinity and to more complicated alterations in the mode of calcium channel activity. PMID:2451004

  10. Noncompaction and embolic myocardial infarction: the importance of oral anticoagulation.

    PubMed

    Pulignano, Giovanni; Tinti, Maria Denitza; Tolone, Stefano; Musto, Carmine; De Lio, Lucia; Pino, Paolo Giuseppe; Minardi, Giovanni; Violini, Roberto; Uguccioni, Massimo

    2015-01-01

    Left ventricular noncompaction (LVNC) is characterized by left ventricular (LV) hypertrabeculations and is associated with heart failure, arrhythmias and embolism. We report the case of a 67-year-old LVNC patient, under oral anticoagulation (OAC) therapy for apical thrombosis. After she discontinued OAC, the thrombus involved almost the whole of the left ventricle; in a few months her condition worsened, requiring hospitalization, and despite heparin infusion she experienced myocardial infarction (MI), caused by embolic occlusion of the left anterior descending artery. Although infrequent as a complication of LVNC, and usually attributable to microvascular dysfunction, in this case MI seems due to coronary thromboembolism from dislodged thrombotic material in the left ventricle. PMID:26162290

  11. The non-compact Weyl equation

    NASA Astrophysics Data System (ADS)

    Doikou, Anastasia; Ioannidou, Theodora

    2011-04-01

    A non-compact version of the Weyl equation is proposed, based on the infinite dimensional spin zero representation of the mathfrak{s}{mathfrak{l}_2} algebra. Solutions of the aforementioned equation are obtained in terms of the Kummer functions. In this context, we discuss the ADHMN approach in order to construct the corresponding non-compact BPS monopoles.

  12. The effect of hexane on the ventricular fibrillation threshold of the isolated perfused rat heart.

    PubMed

    Khedun, S M; Maharaj, B; Leary, W P; Lockett, C J

    1992-01-01

    This investigation was conducted to determine the influence of hexane on the ventricular fibrillation threshold of the isolated perfused rat heart and myocardial electrolyte levels. Ventricular fibrillation threshold was measured using the Langendorff perfusion apparatus. Heart rate was measured by a universal digital counter and the cardiac flow by collecting the outflow of the heating chamber below the heart into a graduated measuring cylinder. Magnesium and zinc were measured by atomic absorption spectrophotometry and potassium by flame photometry. Two groups of rats were studied; those in the experimental group were given 0.2 ml of hexane and the control group 0.2 ml olive oil subcutaneously for 90 days. Their hearts were removed under anaesthesia. Half of the experimental and control hearts were mounted on the Langendorff perfusion apparatus and the heart rate, coronary flow and ventricular fibrillation threshold were measured. The hearts of the other half were used to measure myocardial electrolyte levels. In the experimental group the ventricular fibrillation threshold decreased (4.72 (S.D. +/- 1.87) vs 9.48 (S.D. +/- 2.98); P less than 0.001). There was no change in the coronary flow and heart rate in between the groups. The mean myocardial potassium levels (2586 (S.D. +/- 162) vs 2968 (S.D. +/- 218) micrograms/g; P less than 0.001), magnesium levels (164 (S.D. +/- 28) vs 208 (S.D. +/- 18) micrograms/g; P less than 0.001) and zinc levels (19.6 (S.D. +/- 4) vs 33.8 (S.D. +/- 6.8) micrograms/g; P less than 0.001) were significantly lower in the hexane-treated group compared to controls. Hexane, a constituent of glue and benzine, is cardiotoxic; marked derangement in myocardial electrolytes and a reduced ventricular fibrillation threshold, indicating an increased myocardial vulnerability to arrhythmias, was noted in the experimental animals. PMID:1729763

  13. Singularities of noncompact charged objects

    NASA Astrophysics Data System (ADS)

    Sharif, M.; G., Abbas

    2013-03-01

    We formulate a model for noncompact spherical charged objects in the framework of noncommutative field theory. The Einstein—Maxwell field equations are solved with charged anisotropic fluid. We choose matter and charge densities as functions of the two parameters, instead of defining these quantities in terms of the Gaussian distribution function. It is found that the corresponding densities and the Ricci scalar are singular in origin, whereas the metric is nonsingular, indicating a spacelike singularity. The numerical solution of the horizon equation implies that there are two or one or no horizon(s), depending on the mass. We also evaluate the Hawking temperature and find that a black hole with two horizons is evaporated to an extremal black hole with one horizon.

  14. Differential Expression Levels of Integrin α6 Enable the Selective Identification and Isolation of Atrial and Ventricular Cardiomyocytes

    PubMed Central

    Wiencierz, Anne Maria; Kernbach, Manuel; Ecklebe, Josephine; Monnerat, Gustavo; Tomiuk, Stefan; Raulf, Alexandra; Christalla, Peter; Malan, Daniela; Hesse, Michael; Bosio, Andreas; Fleischmann, Bernd K.; Eckardt, Dominik

    2015-01-01

    Rationale Central questions such as cardiomyocyte subtype emergence during cardiogenesis or the availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, current methodologies do not allow for a transgene-free selective isolation of atrial or ventricular cardiomyocytes due to the lack of subtype specific cell surface markers. Methods and Results In order to develop cell surface marker-based isolation procedures for cardiomyocyte subtypes, we performed an antibody-based screening on embryonic mouse hearts. Our data indicate that atrial and ventricular cardiomyocytes are characterized by differential expression of integrin α6 (ITGA6) throughout development and in the adult heart. We discovered that the expression level of this surface marker correlates with the intracellular subtype-specific expression of MLC-2a and MLC-2v on the single cell level and thereby enables the discrimination of cardiomyocyte subtypes by flow cytometry. Based on the differential expression of ITGA6 in atria and ventricles during cardiogenesis, we developed purification protocols for atrial and ventricular cardiomyocytes from mouse hearts. Atrial and ventricular identities of sorted cells were confirmed by expression profiling and patch clamp analysis. Conclusion Here, we introduce a non-genetic, antibody-based approach to specifically isolate highly pure and viable atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This will facilitate in-depth characterization of the individual cellular subsets and support translational research applications. PMID:26618511

  15. Streptozotocin-induced diabetes prolongs twitch duration without affecting the energetics of isolated ventricular trabeculae

    PubMed Central

    2014-01-01

    Background Diabetes induces numerous electrical, ionic and biochemical defects in the heart. A general feature of diabetic myocardium is its low rate of activity, commonly characterised by prolonged twitch duration. This diabetes-induced mechanical change, however, seems to have no effect on contractile performance (i.e., force production) at the tissue level. Hence, we hypothesise that diabetes has no effect on either myocardial work output or heat production and, consequently, the dependence of myocardial efficiency on afterload of diabetic tissue is the same as that of healthy tissue. Methods We used isolated left ventricular trabeculae (streptozotocin-induced diabetes versus control) as our experimental tissue preparations. We measured a number of indices of mechanical (stress production, twitch duration, extent of shortening, shortening velocity, shortening power, stiffness, and work output) and energetic (heat production, change of enthalpy, and efficiency) performance. We calculated efficiency as the ratio of work output to change of enthalpy (the sum of work and heat). Results Consistent with literature results, we showed that peak twitch stress of diabetic tissue was normal despite suffering prolonged duration. We report, for the first time, the effect of diabetes on mechanoenergetic performance. We found that the indices of performance listed above were unaffected by diabetes. Hence, since neither work output nor change of enthalpy was affected, the efficiency-afterload relation of diabetic tissue was unaffected, as hypothesised. Conclusions Diabetes prolongs twitch duration without having an effect on work output or heat production, and hence efficiency, of isolated ventricular trabeculae. Collectively, our results, arising from isolated trabeculae, reconcile the discrepancy between the mechanical performance of the whole heart and its tissues. PMID:24731754

  16. Biventricular Noncompaction Cardiomyopathy in an Adult with Unique Facial Dysmorphisms: Case Report and Brief Review

    PubMed Central

    Rao, Gaurav; Tauras, James

    2015-01-01

    Left ventricular noncompaction (LVNC) is a rare cardiomyopathy that is believed it to arise from an arrest in embryonic endomyocardial development. More recent studies suggest that it can be acquired later on in life sporadically. It may be accompanied by life-threatening complications, which are most commonly heart failure, arrhythmias, and thromboembolic events. We report a case of biventricular noncompaction cardiomyopathy in a 36-year-old man presenting for the first time with clinical heart failure as well as atrial arrhythmia. Transthoracic echocardiography (TTE) revealed LVNC with depressed ejection fraction (EF). Cardiac magnetic resonance imaging (MRI) further revealed a left atrial appendage thrombus as well as right ventricular noncompaction involvement. His physical exam was unique for a characteristic facial dysmorphisms pattern and developmental delays reminiscent of the earliest descriptions of LVNC in the pediatric population and it was rarely described in adult patients. This unique presentation underscores the importance of a better understanding of the genetics and natural course of LVNC. This will help us to elucidate the uncertainty surrounding its clinical management, discussed in a brief review of the literature following the case. PMID:26266056

  17. Noncompaction and Dilated Cardiomyopathy in a Patient with Schizophrenia

    PubMed Central

    Stöllberger, Claudia

    2016-01-01

    Objectives. Psychosis and left ventricular hypertrabeculation (or noncompaction) (LVHT) have not been described in the same patient. Here we report a patient with a long-term history of schizophrenia who was later diagnosed with dilated cardiomyopathy (dCMP) and LVHT. Case Report. A 47-year-old Caucasian male developed nondifferentiated schizophrenia at the age of 26 y. Since the age of 33 y he was regularly drinking alcohol. At the age of 47 y he developed heart failure. Transthoracic echocardiography showed an enlarged left ventricle, reduced systolic function, and surprisingly LVHT in the apical segment. Additionally, the left atrium was enlarged, the right ventricular cavities were mildly enlarged, and there were pulmonary hypertension and a small pericardial effusion. Cardiac MRI confirmed the echocardiographic findings. Since coronary angiography was normal, dilated cardiomyopathy was additionally diagnosed. Since he was taking clozapine during years, dilated cardiomyopathy could be due to not only alcohol consumption but also the long-term neuroleptic medication. Conclusions. LVHT may be associated with nondifferentiated psychosis. Management of LVHT is challenging in patients with psychosis due to poor compliance and adherence of these patients. Patients with LVHT and psychosis need particular attention since they usually take cardiotoxic drugs for a long time, which may further deteriorate the prognosis of LVHT. PMID:27547471

  18. Pharmacological inhibition of IK1 by PA-6 in isolated rat hearts affects ventricular repolarization and refractoriness.

    PubMed

    Skarsfeldt, Mark A; Carstensen, Helena; Skibsbye, Lasse; Tang, Chuyi; Buhl, Rikke; Bentzen, Bo H; Jespersen, Thomas

    2016-04-01

    The inwardly rectifying potassium current (IK 1) conducted through Kir2.X channels contribute to repolarization of the cardiac action potential and to stabilization of the resting membrane potential in cardiomyocytes. Our aim was to investigate the effect of the recently discovered IK 1 inhibitor PA-6 on action potential repolarization and refractoriness in isolated rat hearts. Transiently transfected HEK-293 cells expressing IK 1 were voltage-clamped with ramp protocols. Langendorff-perfused heart experiments were performed on male Sprague-Dawley rats, effective refractory period, Wenckebach cycle length, and ventricular effective refractory period were determined following 200 nmol/L PA-6 perfusion. 200 nmol/L PA-6 resulted in a significant time-latency in drug effect on the IK 1 current expressed in HEK-293 cells, giving rise to a maximal effect at 20 min. In the Langendorff-perfused heart experiments, PA-6 prolonged the ventricular action potential duration at 90% repolarization (from 41.8 ± 6.5 msec to 72.6 ± 21.1 msec, 74% compared to baseline, P < 0.01, n = 6). In parallel, PA-6 significantly prolonged the ventricular effective refractory period compared to baseline (from 34.8 ± 4.6 msec to 58.1 ± 14.7 msec, 67%, P < 0.01, n = 6). PA-6 increased the short-term beat-to-beat variability and ventricular fibrillation was observed in two of six hearts. Neither atrial ERP nor duration of atrial fibrillation was altered following PA-6 application. The results show that pharmacological inhibition of cardiac IK 1 affects ventricular action potential repolarization and refractoriness and increases the risk of ventricular arrhythmia in isolated rat hearts. PMID:27117805

  19. Infinitely many singular interactions on noncompact manifolds

    SciTech Connect

    Kaynak, Burak Tevfik Turgut, O. Teoman

    2015-05-15

    We show that the ground state energy is bounded from below when there are infinitely many attractive delta function potentials placed in arbitrary locations, while all being separated at least by a minimum distance, on two dimensional non-compact manifold. To facilitate the reading of the paper, we first present the arguments in the setting of Cartan–Hadamard manifolds and then subsequently discuss the general case. For this purpose, we employ the heat kernel techniques as well as some comparison theorems of Riemannian geometry, thus generalizing the arguments in the flat case following the approach presented in Albeverio et al. (2004). - Highlights: • Schrödinger-operator for infinitely many singular interactions on noncompact manifolds. • Proof of the finiteness of the ground-state energy.

  20. Isolated congenital cardiac diverticulum originating from the left ventricular apex: Report of a pediatric case.

    PubMed

    Uysal, Fahrettin; Bostan, Ozlem Mehtap; Toprak, Muhammed Hamza Halil; Signak, Isik Senkaya; Cil, Ergun

    2016-01-01

    Congenital ventricular diverticulum is a rare cardiac anomaly defined as a localized protrusion of the ventricular free wall. Although, it is usually asymptomatic, complications such as embolism, infective endocarditis, and arrhythmias can occur. The diagnosis can be made by echocardiography, cardiac magnetic resonance imaging, or catheter angiography. Surgical resection is the treatment of choice in symptomatic patients, whereas the management of asymptomatic patients often represents a therapeutic dilemma. We report here, a 9-month-old patient with asymptomatic congenital left ventricular (LV) diverticulum associated with epigastric hernia. PMID:27212863

  1. Isolated congenital cardiac diverticulum originating from the left ventricular apex: Report of a pediatric case

    PubMed Central

    Uysal, Fahrettin; Bostan, Ozlem Mehtap; Toprak, Muhammed Hamza Halil; Signak, Isik Senkaya; Cil, Ergun

    2016-01-01

    Congenital ventricular diverticulum is a rare cardiac anomaly defined as a localized protrusion of the ventricular free wall. Although, it is usually asymptomatic, complications such as embolism, infective endocarditis, and arrhythmias can occur. The diagnosis can be made by echocardiography, cardiac magnetic resonance imaging, or catheter angiography. Surgical resection is the treatment of choice in symptomatic patients, whereas the management of asymptomatic patients often represents a therapeutic dilemma. We report here, a 9-month-old patient with asymptomatic congenital left ventricular (LV) diverticulum associated with epigastric hernia. PMID:27212863

  2. Caffeine-induced immobilization of gating charges in isolated guinea-pig ventricular heart cells

    PubMed Central

    Leroy, Jérôme; Lignon, Jacques M; Gannier, François; Argibay, Jorge A; Malécot, Claire O

    2002-01-01

    The effects of 10 mM caffeine (CAF) on intramembrane charge movements (ICM) were studied in isolated guinea-pig ventricular heart cells with the whole-cell patch-clamp technique.In the presence of CAF, the properties (voltage dependence, maximum QON [Qmax], availability with voltage) of QON charge activated from −110 mV were barely affected. Following a 100 ms prepulse to −50 mV to decrease the participation of charges originating from Na channels, the voltage dependence of QON was shifted by 5 mV (negative component) and by 10 mV (positive component) towards negative potentials, and Qmax was depressed by 16.5%.CAF drastically reduced in a time- and voltage-dependent manner QOFF on repolarization to −50 mV, the effects being greater at positive potentials.CAF-induced QOFF immobilization could be almost entirely removed by repolarization to voltages as negative as −170 mV. In these conditions, the voltage-dependence of QOFF (repolarization to +30 to −170 mV) was shifted by 17 mV (negative component) and 30 mV (positive component) towards negative potentials, suggesting an interconversion into charge 2.Most of CAF effects were suppressed when the sarcoplasmic reticulum (SR) was not functional or when the cells were loaded with BAPTA-AM.We conclude that CAF effects on ICM are likely due to Ca2+ ions released from the SR, and which accumulate in the subsarcolemmal fuzzy spaces in the vicinity of the Ca channels. Because CAF effects were more pronounced on QOFF than on QON the channels have likely to open before Ca2+ ions could affect their gating properties. It is speculated that such an effect on gating charges might contribute to the Ca-induced inactivation of the Ca current. PMID:11834620

  3. Itraconazole decreases left ventricular contractility in isolated rabbit heart: Mechanism of action

    SciTech Connect

    Qu, Yusheng; Fang, Mei; Gao, BaoXi; Amouzadeh, Hamid R.; Li, Nianyu; Narayanan, Padma; Acton, Paul; Lawrence, Jeff; Vargas, Hugo M.

    2013-04-15

    Itraconazole (ITZ) is an approved antifungal agent that carries a “black box warning” in its label regarding a risk of negative cardiac inotropy based on clinical findings. Since the mechanism of the negative inotropic effect is unknown, we performed a variety of preclinical and mechanistic studies to explore the pharmacological profile of ITZ and understand the negative inotropic mechanism. ITZ was evaluated in: (1) an isolated rabbit heart (IRH) preparation using Langendorff retrograde perfusion; (2) ion channel studies; (3) a rat heart mitochondrial function profiling screen; (4) a mitochondrial membrane potential (MMP) assay; (5) in vitro pharmacology profiling assays (148 receptors, ion channels, transporters, and enzymes); and (6) a kinase selectivity panel (451 kinases). In the IRH, ITZ decreased cardiac contractility (> 30%) at 0.3 μM, with increasing effect at higher concentrations, which indicated a direct negative inotropic effect upon the heart. It also decreased heart rate and coronary flow (≥ 1 μM) and prolonged PR/QRS intervals (3 μM). In mechanistic studies, ITZ inhibited the cardiac NaV channel (IC{sub 50}: 4.2 μM) and was devoid of any functional inhibitory effect at the remaining pharmacological targets. Lastly, ITZ did not affect MMP, nor interfere with mitochondrial enzymes or processes involved with fuel substrate utilization or energy formation. Overall, the cardiovascular and mechanistic data suggest that ITZ-induced negative inotropy is a direct effect on the heart, in addition, the potential involvement of mitochondria function and L-type Ca{sup 2+} channels are eliminated. The exact mechanism underlying the negative inotropy is uncertain, and requires further study. - Highlights: ► Effect of itraconazole (ITZ) was assessed in the isolated rabbit heart (IRH) assay. ► ITZ decreased ventricular contractility in IRH, indicating a direct effect. ► IC{sub 50} of ITZ on L-type I{sub Ca} was greater than 30 μM, on I{sub Na} was 4

  4. Ventricular filling slows epicardial conduction and increases action potential duration in an optical mapping study of the isolated rabbit heart

    NASA Technical Reports Server (NTRS)

    Sung, Derrick; Mills, Robert W.; Schettler, Jan; Narayan, Sanjiv M.; Omens, Jeffrey H.; McCulloch, Andrew D.; McCullough, A. D. (Principal Investigator)

    2003-01-01

    INTRODUCTION: Mechanical stimulation can induce electrophysiologic changes in cardiac myocytes, but how mechanoelectric feedback in the intact heart affects action potential propagation remains unclear. METHODS AND RESULTS: Changes in action potential propagation and repolarization with increased left ventricular end-diastolic pressure from 0 to 30 mmHg were investigated using optical mapping in isolated perfused rabbit hearts. With respect to 0 mmHg, epicardial strain at 30 mmHg in the anterior left ventricle averaged 0.040 +/- 0.004 in the muscle fiber direction and 0.032 +/- 0.006 in the cross-fiber direction. An increase in ventricular loading increased average epicardial activation time by 25%+/- 3% (P < 0.0001) and correspondingly decreased average apparent surface conduction velocity by 16%+/- 7% (P = 0.007). Ventricular loading did not significantly alter action potential duration at 20% repolarization (APD20) but did at 80% repolarization (APD80), from 179 +/- 7 msec to 207 +/- 5 msec (P < 0.0001). The dispersion of APD20 was decreased with loading from 19 +/- 2 msec to 13 +/- 2 msec (P = 0.024), whereas the dispersion of APD80 was not significantly changed. These electrophysiologic changes with ventricular loading were not affected by the nonspecific stretch-activated channel blocker streptomycin (200 microM) and were not attributable to changes in myocardial perfusion or the presence of an electromechanical decoupling agent (butanedione monoxime) during optical mapping. CONCLUSION: Acute loading of the left ventricle of the isolated rabbit heart decreased apparent epicardial conduction velocity and increased action potential duration by a load-dependent mechanism that may not involve stretch-activated channels.

  5. [Isolated left ventricular--right atrial shunt after blunt chest trauma (author's transl)].

    PubMed

    Kreuzer, E; Beyer, J

    1978-12-01

    A case of left-ventricular-right-atrial septal defect secundary to blunt chest trauma is described. The etiology of this type of septal defect, e. g. congenital, following aortic and mitral valve replacement, endocarditis and trauma, is discussed. Early defect closure is recommended in the presence of significant shunt volume. PMID:751280

  6. A high-resolution thermoelectric module-based calorimeter for measuring the energetics of isolated ventricular trabeculae at body temperature.

    PubMed

    Johnston, Callum M; Han, June-Chiew; Ruddy, Bryan P; Nielsen, Poul M F; Taberner, Andrew J

    2015-07-15

    Isolated ventricular trabeculae are the most common experimental preparations used in the study of cardiac energetics. However, the experiments have been conducted at subphysiological temperatures. We have overcome this limitation by designing and constructing a novel calorimeter with sufficiently high thermal resolution for simultaneously measuring the heat output and force production of isolated, contracting, ventricular trabeculae at body temperature. This development was largely motivated by the need to better understand cardiac energetics by performing such measurements at body temperature to relate tissue performance to whole heart behavior in vivo. Our approach uses solid-state thermoelectric modules, tailored for both temperature sensing and temperature control. The thermoelectric modules have high sensitivity and low noise, which, when coupled with a multilevel temperature control system, enable an exceptionally high temperature resolution with a noise-equivalent power an order of magnitude greater than those of other existing muscle calorimeters. Our system allows us to rapidly and easily change the experimental temperature without disturbing the state of the muscle. Our calorimeter is useful in many experiments that explore the energetics of normal physiology as well as pathophysiology of cardiac muscle. PMID:26001412

  7. Non-compact nonlinear sigma models

    NASA Astrophysics Data System (ADS)

    de Rham, Claudia; Tolley, Andrew J.; Zhou, Shuang-Yong

    2016-09-01

    The target space of a nonlinear sigma model is usually required to be positive definite to avoid ghosts. We introduce a unique class of nonlinear sigma models where the target space metric has a Lorentzian signature, thus the associated group being non-compact. We show that the would-be ghost associated with the negative direction is fully projected out by 2 second-class constraints, and there exist stable solutions in this class of models. This result also has important implications for Lorentz-invariant massive gravity: There exist stable nontrivial vacua in massive gravity that are free from any linear vDVZ-discontinuity and a Λ2 decoupling limit can be defined on these vacua.

  8. MRI assessment of pacing induced ventricular dyssynchrony in an isolated human heart.

    PubMed

    Eggen, Michael D; Bateman, Michael G; Rolfes, Christopher D; Howard, Stephen A; Swingen, Cory M; Iaizzo, Paul A

    2010-02-01

    This study demonstrates the capabilities of MRI in the assessment of cardiac pacing induced ventricular dyssynchrony, and the findings support the need for employing more physiological pacing. A human donor heart deemed non-viable for transplantation, was reanimated using an MR compatible, four-chamber working perfusion system. The heart was imaged using a 1.5T MR scanner while being paced from the right ventricular apex (RVA) via an epicardial placed lead. Four-chamber, short-axis, and tagged short-axis cines were acquired in order to track wall motion and intramyocardial strain during pacing. The results of this study revealed that the activation patterns of the left ventricle (LV) during RVA pacing demonstrated intraventricular dyssynchrony; as the left ventricular mechanical activation proceeded from the septum and anterior wall to the lateral wall, with the posterior wall being activated last. As such, the time difference to peak contraction between the septum and lateral wall was approximately 125 msec. Likewise, interventricular dyssynchrony was demonstrated from the four-chamber cine as the time difference between the peak LV and RV free wall motion was 180 msec. With the ongoing development of MR safe and MR compatible pacing systems, we can expect MRI to be added to the list of imaging modalities used to optimize cardiac resynchronization therapy (CRT) and/or alternate site pacing. PMID:20099368

  9. MRI Assessment of Pacing Induced Ventricular Dyssynchrony in an Isolated Human Heart

    PubMed Central

    Eggen, Michael D.; Bateman, Michael G.; Rolfes, Christopher D.; Howard, Stephen A.; Swingen, Cory M.; Iaizzo, Paul A.

    2010-01-01

    This study demonstrates the capabilities of MR imaging in the assessment of cardiac pacing induced ventricular dyssynchrony, and findings support the need for employing more physiological pacing. A human donor heart deemed non-viable for transplantation, was reanimated using an MR compatible, four-chamber working perfusion system. The heart was imaged using a 1.5T MR scanner while being paced from the right ventricular apex (RVA) via an epicardial placed lead. Four-chamber, short-axis, and tagged short-axis cines were acquired in order track wall motion and intramyocardial strain during pacing. The results of this study revealed that the activation patterns of the left ventricle (LV) during RVA pacing demonstrated intraventricular dyssynchrony; as the left ventricular mechanical activation proceeded from the septum and anterior wall to the lateral wall, with the posterior wall being activated last. As such, the time difference to peak contraction between the septum and lateral wall was ∼125 ms. Likewise, interventricular dyssynchrony was demonstrated from the four-chamber cine as the time difference between the peak LV and RV free wall motion was 180 ms. With the ongoing development of MR safe and MR compatible pacing systems, we can expect MRI to be added to the list of imaging modalities used to optimize cardiac resynchronization therapy and/or alternate site pacing. PMID:20099368

  10. Prolonged asystole in a patient with an isolated left ventricular assist device.

    PubMed

    Javed, Wasim; Chaggar, Parminder S; Venkateswaran, Rajamiyer; Shaw, Steven M

    2016-09-01

    Left ventricular assist devices (LVADs) are well established in the management of end-stage heart failure as either destination therapy, a bridge prior to cardiac transplantation or during myocardial recovery. Despite LVADs requiring adequate left ventricular preload to effectively augment systemic circulation, there have been rare cases of patients with LVADs surviving sustained, normally fatal arrhythmias, such as ventricular fibrillation and asystole. Whilst current reports describe an LVAD patient surviving 15 days with such an arrhythmia, we describe the case of a patient with an LVAD surviving 104 days of asystole via a Fontan mechanism of circulation, which we believe is the longest known survival of a sustained fatal arrhythmia. This case highlights the physiology of circulations supported by LVADs and the unique challenges that may arise in managing ambulant LVAD patients, such as predicting prognosis. Given the increasing use of LVADs to treat end-stage heart failure, these issues are likely to become more frequently encountered in the future. PMID:27539188

  11. A combination of right ventricular hypertrabeculation/noncompaction and arrhythmogenic right ventricular cardiomyopathy: a syndrome?

    PubMed Central

    Song, Ze-Zhou

    2008-01-01

    A combination of ARVC and RV NVM/HVM, which is extremely rare, to our knowledge, is never reported. RV NVM/HVM could be the cause and consequence of ARVC, or RV NVM/HVM and ARVC could be a consequence of a certain undetermined cause. It must be kept in mind, however, that the interaction of NVM/HVM and ARVC could be in part of pathophysiology mechanism of the combination even if as a consequence of an underlying genetic factor. PMID:19105817

  12. The hypertrabeculated (noncompacted) left ventricle is different from the ventricle of embryos and ectothermic vertebrates.

    PubMed

    Jensen, Bjarke; Agger, Peter; de Boer, Bouke A; Oostra, Roelof-Jan; Pedersen, Michael; van der Wal, Allard C; Nils Planken, R; Moorman, Antoon F M

    2016-07-01

    Ventricular hypertrabeculation (noncompaction) is a poorly characterized condition associated with heart failure. The condition is widely assumed to be the retention of the trabeculated ventricular design of the embryo and ectothermic (cold-blooded) vertebrates. This assumption appears simplistic and counterfactual. Here, we measured a set of anatomical parameters in hypertrabeculation in man and in the ventricles of embryos and animals. We compared humans with left ventricular hypertrabeculation (N=21) with humans with structurally normal left ventricles (N=54). We measured ejection fraction and ventricular trabeculation using cardiovascular MRI. Ventricular trabeculation was further measured in series of embryonic human and 9 animal species, and in hearts of 15 adult animal species using MRI, CT, or histology. In human, hypertrabeculated left ventricles were significantly different from structurally normal left ventricles by all structural measures and ejection fraction. They were far less trabeculated than human embryonic hearts (15-40% trabeculated volume versus 55-80%). Early in development all vertebrate embryos acquired a ventricle with approximately 80% trabeculations, but only ectotherms retained the 80% trabeculation throughout development. Endothermic (warm-blooded) animals including human slowly matured in fetal and postnatal stages towards ventricles with little trabeculations, generally less than 30%. Further, the trabeculations of all embryos and adult ectotherms were very thin, less than 50 μm wide, whereas the trabeculations in adult endotherms and in the setting of hypertrabeculation were wider by orders of magnitude. It is concluded in contrast to a prevailing assumption, the hypertrabeculated left ventricle is not like the ventricle of the embryo or of adult ectotherms. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes

  13. Effects of pethidine and nalorphine on the mechanical and electrical activities of mammalian isolated ventricular muscle.

    PubMed

    Grundy, H F; Tritthart, H

    1972-09-01

    1. The strength of the isometric mechanical contraction of electricallydriven ventricular muscle has been recorded simultaneously with the resting and action potentials; the effects of pethidine and of nalorphine on these parameters have been studied.2. When lower concentrations of pethidine (0.22-6.5 mug/ml) were perfused, isometric peak tension was decreased in parallel with the maximum upstroke velocity of the action potential; these actions are considered to result from membrane stabilization. At higher concentrations (11.8-109 mug/ml) pethidine usually produced, in addition, a progressive decrease in the resting and action potentials associated with marked irregularities in, or even abolition of, the mechanical response. It is suggested that these effects of the higher doses might be due to a depression of ATPase activity in the myocardial membrane.3. Compared with pethidine, nalorphine had similar, but weaker, actions. PMID:4263795

  14. Compound heterozygous or homozygous truncating MYBPC3 mutations cause lethal cardiomyopathy with features of noncompaction and septal defects

    PubMed Central

    Wessels, Marja W; Herkert, Johanna C; Frohn-Mulder, Ingrid M; Dalinghaus, Michiel; van den Wijngaard, Arthur; de Krijger, Ronald R; Michels, Michelle; de Coo, Irenaeus FM; Hoedemaekers, Yvonne M; Dooijes, Dennis

    2015-01-01

    Familial hypertrophic cardiomyopathy (HCM) is usually caused by autosomal dominant pathogenic mutations in genes encoding sarcomeric or sarcomere-associated cardiac muscle proteins. The disease mainly affects adults, although young children with severe HCM have also been reported. We describe four unrelated neonates with lethal cardiomyopathy, and performed molecular studies to identify the genetic defect. We also present a literature overview of reported patients with compound heterozygous or homozygous pathogenic MYBPC3 mutations and describe their clinical characteristics. All four children presented with feeding difficulties, failure to thrive, and dyspnea. They died from cardiac failure before age 13 weeks. Features of left ventricular noncompaction were diagnosed in three patients. In the fourth, hypertrabeculation was not a clear feature, but could not be excluded. All of them had septal defects. Two patients were compound heterozygotes for the pathogenic c.2373dup p.(Trp792fs) and c.2827C>T p.(Arg943*) mutations, and two were homozygous for the c.2373dup and c.2827C>T mutations. All patients with biallelic truncating pathogenic mutations in MYBPC3 reported so far (n=21) were diagnosed with severe cardiomyopathy and/or died within the first few months of life. In 62% (13/21), septal defects or a patent ductus arteriosus accompanied cardiomyopathy. In contrast to heterozygous pathogenic mutations, homozygous or compound heterozygous truncating pathogenic MYBPC3 mutations cause severe neonatal cardiomyopathy with features of left ventricular noncompaction and septal defects in approximately 60% of patients. PMID:25335496

  15. Regulation of unloaded cell shortening by sarcolemmal sodium-calcium exchange in isolated rat ventricular myocytes.

    PubMed Central

    Bouchard, R A; Clark, R B; Giles, W R

    1993-01-01

    1. Regulation of unloaded cell shortening and relaxation by sarcolemmal Na(+)-Ca2+ exchange was investigated in rat ventricular myocytes. Contraction of single cells at 22 +/- 1 degrees C was measured simultaneously with membrane current and voltage using the whole-cell voltage clamp technique in combination with a video edge-detection device. 2. The extent of mechanical activation (cell shortening amplitude) was strongly dependent on diastolic membrane potential over the voltage range -140 to -50 mV. This voltage sensitivity of contraction was abolished completely when a recently described inhibitory peptide of the cardiac Na(+)-Ca2+ exchanger (XIP, 2 x 10(-5) M) was present in the recording pipette, demonstrating that in rat ventricular cells Na(+)-Ca2+ exchange is modulated by diastolic membrane potential. 3. Possible influences of Na(+)-Ca2+ exchange on contraction were studied from a holding potential of -80 mV. Depolarizations (-50 to +60 mV) resulted in a bell-shaped shortening-voltage (S-V) relationship. These contractions were suppressed completely by either Cd2+ (10(-4) M) or verapamil (10(-5) M), but remained unchanged during superfusion with tetrodotoxin (TTX, 1.5 x 10(-5) M), when [NA+]o was reduced from 140 to 10 mM by substitution with either Li+ or Cs+ ions or when pipette Na+ was varied between 8 and 13 mM. XIP (2 x 10(-5) M) increased the magnitude and duration of twitch contractions, but had no effect on the shape of the S-V relationship. Thus, the Ca2+ current but not the Na+ current or Ca2+ influx due to reversed Na(+)-Ca2+ exchange can release Ca2+ from the sarcoplasmic reticulum (SR) under these experimental conditions. 4. The effect of the rate of repolarization on cell shortening was studied under voltage clamp by applying ramp waveforms immediately following the depolarizations which activated contraction. Although slowing of the rate of repolarization had no effect on the first contraction following a train of conditioning depolarizations

  16. High-frequency periodic sources underlie ventricular fibrillation in the isolated rabbit heart.

    PubMed

    Chen, J; Mandapati, R; Berenfeld, O; Skanes, A C; Jalife, J

    The mechanism(s) underlying ventricular fibrillation (VF) remain unclear. We hypothesized that at least some forms of VF are not random and that high-frequency periodic sources of activity manifest themselves as spatiotemporal periodicities, which drive VF. Twenty-four VF episodes from 8 Langendorff-perfused rabbit hearts were studied using high-resolution video imaging in conjunction with ECG recordings and spectral analysis. Sequential wavefronts that activated the ventricles in a spatially and temporally periodic fashion were identified. In addition, we analyzed the lifespan and dynamics of wavelets in VF, using a new method of phase mapping that enables identification of phase singularity points (PSs), which flank individual wavelets. Spatiotemporal periodicity was found in 21 of 24 episodes. Complete reentry on the epicardial surface was observed in 3 of 24 episodes. The cycle length of discrete regions of spatiotemporal periodicity correlated highly with the dominant frequency of the optical pseudo-ECG (R(2)=0.75) and with the global bipolar electrogram (R(2)=0.79). The lifespan of PSs was short (14.7+/-14.4 ms); 98% of PSs existed for <1 rotation. The mean number of waves entering (6.50+/-0.69) exceeded the mean number of waves that exited our mapping field (4.25+/-0.56; P<0.05). These results strongly suggest that ongoing stable sources are responsible for the majority of the frequency content of VF and therefore play a role in its maintenance. In this model, multiple wavelets resulting from wavebreaks do not appear to be responsible for the sustenance of this arrhythmia, but are rather the consequence of breakup of high-frequency activation from a dominant reentrant source. PMID:10625309

  17. Characterization and agonist regulation of muscarinic ([3H]N-methyl scopolamine) receptors in isolated ventricular myocytes from rat.

    PubMed

    Horackova, M; Robinson, B; Wilkinson, M

    1990-11-01

    Cell surface muscarinic cholinergic receptors have been characterized and quantified for the first time, in intact, isolated adult rat cardiomyocytes. The cells were previously established as functionally fully compatible with cellular responses in intact cardiac tissue. The specific binding of the hydrophilic radioligand, [3H]-NMS, (N-methyl-[3H]-scopolamine methylchloride) was found to be stereo-specific, saturable, reversible and of high affinity. Binding of [3H]-NMS demonstrated appropriate drug specificity and was positively correlated with increasing cell concentrations. Bmax for [3H]-NMS binding to ventricular myocytes, enzymatically dissociated from adult male rats, was 15.8 +/- 1.03 fmol/25 x 10(3) cells (at 4 degrees C) and KD was 0.27 +/- 0.05 nM (n = 14). Binding assays performed at a higher incubation temperature (30 degrees C) yielded a higher Bmax value (22.1 +/- 1.6 fmol/25 x 10(3) cells; n = 11; P less than 0.005 vs. Bmax at 4 degrees C) but an unchanged KD (0.23 +/- 0.06 nM). Pretreatment of myocytes with the muscarinic agonist carbachol (1 mM) at 37 degrees C resulted in a reduction (down-regulation) in specific binding of the hydrophilic ligand [3H]-NMS. The magnitude of this reduction and its rate of recovery were dependent on the time of the exposure to carbachol. Exposures of 30-60 min elicited down-regulated by 35% (Bmax = 14.29 +/- 1.66 changed to 9.5 +/- 1.79 fmol/25 x 10(3) cells, without change in KD P less than 0.01, n = 4). The down-regulation of the muscarinic receptors by carbachol was insensitive to application of bacitracin - an inhibitor of endocytosis. On the other hand preincubation with 10(-9)M atropine, a muscarinic antagonist, hindered the agonist-induced receptor "loss" from the cell surface confirming the muscarinic nature of these receptors. We conclude that our preparation of intact, isolated ventricular cardiomyocytes is ideally suited for the study of cell surface muscarinic receptor regulation under physiological and

  18. A new class III antiarrhythmic drug, MS-551, blocks the inward rectifier potassium channel in isolated guinea pig ventricular myocytes.

    PubMed

    Sato, R; Koumi, S; Hisatome, I; Takai, H; Aida, Y; Oyaizu, M; Karasaki, S; Mashiba, H; Katori, R

    1995-07-01

    We have studied the effects of MS-551 on the inward rectifier potassium channel (IK1) in isolated guinea-pig ventricular myocytes by use of whole-cell and single-channel recording techniques. MS-551 (5 microM) blocked the IK1 current. The percent blockade of the peak and steady-state IK1 current by MS-551 was constant at each test potential. In contrast 50 microM MS-551 failed to block either the sodium or the calcium current. Under cell-attached patch conditions, MS-551 reduced the open probability of IK1 channel activity by prolonging the interburst interval without changing either the unitary amplitude or the equilibrium potential. The blockade of IK1 was concentration-dependent. MS-551 did not change either the mean open time or mean closed time within a burst. Extracellular acidification (pH 6.4) strongly attenuated the effect of MS-551 on the open probability of IK1 channel activity when compared with its effect at pH 7.4. In summary, our results demonstrated that MS-551 blocked the IK1 channel. The neutral form of this drug molecules may penetrate the cardiac cell membrane via a hydrophobic pathway to block the steady-state IK1 current by reduction of open probability. PMID:7616432

  19. Right aortic arch with isolation of the left innominate artery in a case of double chamber right ventricle and ventricular septal defect.

    PubMed

    Mangukia, Chirantan; Sethi, Sonali; Agarwal, Saket; Mishra, Smita; Satsangi, Deepak Kumar

    2014-05-01

    Herein, we report an unusual case of right aortic arch with isolation of the left innominate artery in a case of double chamber right ventricle with ventricular septal defect. The blood supply to the innominate artery was by a collateral arising from the descending aorta. The embryological development of this anomaly can be explained by the hypothetical double aortic arch model proposed by Edwards with interruption of the arch at two levels. PMID:24987265

  20. Three-Dimensional Endo-Cardiovascular Volume-Rendered Cine Computed Tomography of Isolated Left Ventricular Apical Hypoplasia: A Case Report and Literature Review.

    PubMed

    Hong, Sun Hwa; Kim, Yang Min; Lee, Hyun Jong

    2016-01-01

    We report multidetector computed tomography (MDCT) and cardiac magnetic resonance (CMR) findings of a 34-year-old female with isolated left ventricular apical hypoplasia. The MDCT and CMR scans displayed a spherical left ventricle (LV) with extensive fatty infiltration within the myocardium at the apex, interventricular septum and inferior wall, anteroapical origin of the papillary muscle, right ventricle wrapping around the deficient LV apex, and impaired systolic function. MDCT visualized morphologic and also functional findings of this unique cardiomyopathy. PMID:26798219

  1. Cardiotoxicity of emetine dihydrochloride by calcium channel blockade in isolated preparations and ventricular myocytes of guinea-pig hearts.

    PubMed Central

    Lemmens-Gruber, R.; Karkhaneh, A.; Studenik, C.; Heistracher, P.

    1996-01-01

    1. The cardiotoxic effects of emetine dihydrochloride on mechanical and electrical activity were studied in isolated preparations (papillary muscles, sinoatrial and atrioventricular nodes, ventricular myocytes) of the guinea-pig heart. 2. Force of contraction was measured isometrically, action potentials and maximum rate of rise of the action potential were recorded by means of the intracellular microelectrode technique. Single channel L-type calcium current (Ba2+ ions as charge carrier) was studied with the patch-clamp technique in the cell-attached mode. 3. Emetine dihydrochloride (8-256 microM) reduced force of contraction in papillary muscles and spontaneous activity of sinoatrial and atrioventricular nodes concentration-dependently; the negative inotropic effect was abolished when the extracellular Ca2+ concentration was increased. 4. Maximum diastolic potential, action potential amplitude, maximum rate of rise of the action potential and the slope of the slow diastolic depolarization were decreased by emetine in sinoatrial as well as atrioventricular noes, while action potential duration was prolonged in both preparations (1-64 microM). 5. The amplitude of the L-type calcium single channel current was not altered by emetine dihydrochloride, while average open state probability was decreased concentration-dependently (10, 30 and 60 microM). 6. The most prominent effect of emetine dihydrochloride on single channel current was an increase of sweeps without activity. 7. At 60 microM, emetine dihydrochloride caused a decrease of the mean open time an increase of the mean closed time. The number of openings per record and number of bursts per record were reduced. 8. It is concluded that emetine dihydrochloride produces an L-type calcium channel block which might contribute to its cardiac side effects. PMID:8789394

  2. Mechanism of extracellular ATP-induced increase of cytosolic Ca2+ concentration in isolated rat ventricular myocytes.

    PubMed Central

    Christie, A; Sharma, V K; Sheu, S S

    1992-01-01

    1. Changes in the cytosolic Ca2+ concentration ([Ca2+]i) of isolated rat ventricular myocytes in suspension were measured in response to extracellular ATP using the fluorescent Ca2+ indicators Quin-2 and Fura-2. 2. ATP produced a concentration-, time- and Mg(2+)-dependent, biphasic increase of [Ca2+]i whereas slowly hydrolysable ATP analogues produced a slow, monophasic increase of [Ca2+]i and the non-hydrolysable ATP analogues were without effect. 3. Extracellular Ca2+ was required for the ATP-induced increase of [Ca2+]i and pre-treatment of the cells with caffeine, ryanodine, verapamil or nimodipine partially inhibited the [Ca2+]i increase. 4. Whole-cell patch-clamp experiments revealed that ATP activated an ionic current that had a linear current-voltage relationship with a reversal potential near O mV. Quinidine, a putative P2 purinergic receptor blocker, abolished the ATP-activated current. The ATP-activated current was Mg2+ dependent. 5. Associated with the ATP-activated current was cellular depolarization. In a physiological solution, ATP depolarized cells to the threshold for the firing of action potentials. In the presence of the voltage-activated ion channel blockers tetrodotoxin, 4-aminopyridine, caesium and nitrendipine, ATP depolarized cells to -44 +/- 6 mV from a resting potential of -66 +/- 4 mV (n = 11). 6. Sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis and autoradiography demonstrated that extracellular ATP stimulated the phosphorylation of several extracellular membrane-bound proteins. The phosphorylation of these proteins was concentration, time and Mg2+ dependent. Pre-treatment of cells with the slowly hydrolysable ATP analogues inhibited the ATP-induced phosphorylation. Adenosine 5'-O-3-thiotriphosphate (ATP gamma S) thiophosphorylated proteins with the same apparent molecular weight as the proteins phosphorylated by ATP. 7. These results suggest that the ATP-induced increase of [Ca2+]i is a result of the activation, possibly

  3. Modulation of L-type Ca2+ current by extracellular ATP in ferret isolated right ventricular myocytes.

    PubMed Central

    Qu, Y; Campbell, D L; Strauss, H C

    1993-01-01

    1. The effects of extracellular adenosine triphosphate (ATP) on the basal L-type Ca2+ current (ICa) were investigated in ferret isolated right ventricular myocytes using the gigaohm seal voltage clamp in the whole-cell and cell-attached configurations. 2. Micromolar levels of extracellular ATP reversibly inhibited ICa in a concentration-dependent manner, without any significant changes in the voltage dependence of either the peak ICa I-V relationship or steady-state activation curve. 3. In contrast, micromolar levels of extracellular ATP did significantly alter the inactivation characteristics of ICa. Ten micromolar ATP: (i) increased the degree of steady-state inactivation of ICa; (ii) altered the time constants of ICa inactivation at 0 mV; and (iii) decreased the time constant of ICa recovery from inactivation at -70 mV. 4. The inhibitory effect of ATP on ICa was not blocked by atropine, a muscarinic cholinergic receptor antagonist, or CPDPX (8-cyclopentyl-3,4-dipropylxanthine), an A1 adenosine receptor antagonist. In contrast, the inhibitory effect of 10 microM ATP could be nearly completely antagonized by 100 microM suramin, a purinergic P2 receptor antagonist. 5. The potency order of ATP analogues in inhibiting ICa was 2-methyl-thio-ATP > ATP > alpha,beta-methylene-ATP, indicating involvement of a P2Y-type ATP receptor. 6. Pretreatment of cells with pertussis toxin (PTX) did not prevent the ATP-induced decrease in ICa. However, (i) ATP produced an irreversible decrease of ICa in the presence of intracellular GTP gamma S, and (ii) the inhibitory effect was significantly attenuated in the presence of intracellular GDP beta S, indicating the involvement of a PTX-insensitive G protein in the P2Y receptor-coupling process. 7. Neither (i) replacing extracellular Ca2+ with 1 mM Ba2+, nor (ii) intracellular perfusion of 10 mM BAPTA for at least 30 min attenuated the inhibitory effect of ATP on the current through Ca2+ channels, suggesting that the inhibitory effect

  4. Left ventricular restoration devices.

    PubMed

    Oliveira, Guilherme H; Al-Kindi, Sadeer G; Bezerra, Hiram G; Costa, Marco A

    2014-04-01

    Left ventricular (LV) remodeling results in continuous cardiac chamber enlargement and contractile dysfunction, perpetuating the syndrome of heart failure. With current exhaustion of the neurohormonal medical paradigm, surgical and device-based therapies have been increasingly investigated as a way to restore LV chamber architecture and function. Left ventricular restoration has been attempted with surgical procedures, such as partial left ventriculectomy, surgical ventricular restoration with or without revascularization, and devices, such as the Acorn CorCap, the Paracor HeartNet, and the Myocor Myosplint. Whereas all these techniques require surgical access, with or without cardiopulmonary bypass, a newer ventricular partitioning device (VPD) called Parachute, can be delivered percutaneously through the aortic valve. Designed to achieve LV restoration from within the ventricle, this VPD partitions the LV by isolating aneurysmal from normal myocardium thereby diminishing the functioning cavity. This review aims to critically appraise the above methods, with particular attention to device-based therapies. PMID:24574107

  5. Role of left ventricular twist mechanics in cardiomyopathies, dance of the helices

    PubMed Central

    Kauer, Floris; Geleijnse, Marcel Leonard; van Dalen, Bastiaan Martijn

    2015-01-01

    Left ventricular twist is an essential part of left ventricular function. Nevertheless, knowledge is limited in “the cardiology community” as it comes to twist mechanics. Fortunately the development of speckle tracking echocardiography, allowing accurate, reproducible and rapid bedside assessment of left ventricular twist, has boosted the interest in this important mechanical aspect of left ventricular deformation. Although the fundamental physiological role of left ventricular twist is undisputable, the clinical relevance of assessment of left ventricular twist in cardiomyopathies still needs to be established. The fact remains; analysis of left ventricular twist mechanics has already provided substantial pathophysiological understanding on a comprehensive variety of cardiomyopathies. It has become clear that increased left ventricular twist in for example hypertrophic cardiomyopathy may be an early sign of subendocardial (microvascular) dysfunction. Furthermore, decreased left ventricular twist may be caused by left ventricular dilatation or an extensive myocardial scar. Finally, the detection of left ventricular rigid body rotation in noncompaction cardiomyopathy may provide an indispensible method to objectively confirm this difficult diagnosis. All this endorses the value of left ventricular twist in the field of cardiomyopathies and may further encourage the implementation of left ventricular twist parameters in the “diagnostic toolbox” for cardiomyopathies. PMID:26322187

  6. Dietary pre-exposure of rats to fish oil does not enhance myocardial efficiency of isolated working hearts or their left ventricular trabeculae

    PubMed Central

    Goo, Soyeon; Han, June-Chiew; Nisbet, Linley A; LeGrice, Ian J; Taberner, Andrew J; Loiselle, Denis S

    2014-01-01

    Numerous epidemiological studies, supported by clinical and experimental findings, have suggested beneficial effects of dietary fish or fish oil supplementation on cardiovascular health. One such experimental study showed a profound (100%) increase in myocardial efficiency (i.e. the ratio of work output to metabolic energy input) of the isolated whole heart, achieved by a corresponding decrease in the rate of myocardial oxygen consumption. However, a number of other investigations have returned null results on the latter energetic index. Such conflicting findings have motivated us to undertake a re-examination. To that effect, we investigated the effects of dietary fatty acid supplementation on myocardial mechano–energetics, with our primary focus on cardiac efficiency. We used both isolated hearts and isolated left ventricular trabeculae of rats fed with one of three distinct diets: reference (REF), fish oil-supplemented (FO) or saturated fat-supplemented (SFA). For all three groups, and at both spatial levels, we supplied 10 mm glucose as the exogenous metabolic substrate. In the working heart experiments, we found no difference in the average mechanical efficiency among the three dietary groups: 14.8 ± 1.1% (REF), 13.9 ± 0.6% (FO) and 13.6 ± 0.7% (SFA). Likewise, we observed no difference in peak mechanical efficiency of left ventricular trabeculae among the REF, FO and SFA groups: 13.3 ± 1.4, 11.2 ± 2.2 and 12.5 ± 1.5%, respectively. We conclude that there is no effect of a period of pre-exposure to a diet supplemented with either fish oil or saturated fatty acids on the efficiency of the myocardium at either spatial level: tissue or whole heart. PMID:24535444

  7. Protection against cardiac anoxia--role and limitations of increased glycogen reserves in the isolated rat right ventricular strip.

    PubMed

    Towart, R; Schlossmann, K; Kazda, S

    1981-01-01

    The effects of drugs on rat cardiac glycogen reserves in vivo, and on the subsequent in vitro sensitivity of the right ventricular strip preparation to anoxia have been investigated. Isoproterenol (0.2 mg/kg i.p.) causes immediate cardiac stimulation and reduction of glycogen reserves, coupled with an increased susceptibility to anoxia. Several hours after administration, glycogen levels are found to be greatly (100-200%) increased, by a "supercompensation" mechanism, and a marked tolerance to anoxia can be simultaneously demonstrated. In contrast, large doses of corticosteroids (dexamethasone, 8 mg/kg i.m.) increase glycogen levels without initial stimulation and glycogen depletion; increased myocardial tolerance to anoxia parallels the increase in glycogen reserves in vivo. We conclude that the myocardial tolerance to anoxia in this model is related to increased glycogen reserves, which increase the rate and/or duration of anaerobic glycolysis during anoxia. PMID:7332516

  8. Closure of aorto-right ventricular tunnel with Amplatzer duct occluder II.

    PubMed

    Vijayalakshmi, I B; Narasimhan, Chitra; Agarwal, Ashish

    2013-04-01

    Aorto-right ventricular tunnel (ARVT) is a very rare, congenital, abnormal extracardiac channel that connects the ascending aorta at or above the sinotubular junction to the cavity of the right ventricle. Only 16 cases have been reported thus far in the English literature. We report the first transcatheter closure of ARVT with the Amplatzer duct occluder II in an infant, with both coronary arteries arising from the left coronary sinus and with biventricular apical non-compaction. PMID:23549501

  9. Knockout of SRC-1 and SRC-3 in Mice Decreases Cardiomyocyte Proliferation and Causes a Noncompaction Cardiomyopathy Phenotype

    PubMed Central

    Chen, Xian; Qin, Li; Liu, Zhaoliang; Liao, Lan; Martin, James F.; Xu, Jianming

    2015-01-01

    Noncompaction cardiomyopathy (NCC) is a congenital heart disease that causes ventricular dysfunction and high mortality rate in children. The mechanisms responsible for NCC are still unknown. The steroid receptor coactivator-1 (SRC-1) and SRC-3 are transcriptional coactivators for nuclear hormone receptors and certain other transcription factors that regulate many genes in development and organ function. However, the roles of SRC-1/3 in heart morphogenesis, function and NCC occurrence are unknown. This study aims to examine the spatial and temporal expression patterns of SRC-1/3 in the heart and investigate the specific roles of SRC-1/3 in heart development, function and NCC occurrence. Immunochemical analysis detected SRC-1/3 expressions in the proliferating cardiomyocytes of mouse heart at prenatal and neonatal stages, while these expressions disappeared within two weeks after birth. Through generating and characterizing mouse lines with global or cardiomyocyte-specific knockouts of SRC-1/3, we found ablation of SRC-1/3 in the myocardial lineage resulted in prominent trabeculae, deep intertrabecular recesses and thin ventricular wall and septum. These developmental defects caused a failure of trabecular compaction, decreased internal ventricular dimension, reduced cardiac ejection fraction and output and led to a high rate of postnatal mortality. Collectively, these structural and functional abnormalities closely simulate the phenotype of NCC patients. Further molecular analysis of cardiomyocytes in vivo and in vitro revealed that SRC-1/3 directly up-regulate cyclin E2, cyclin B1 and myocardin to promote cardiomyocyte proliferation and differentiation. In conclusion, SRC-1/3 are required for cardiomyocyte proliferation and differentiation at earlier developmental stages, and their dysfunction causes NCC-like abnormalities in the hearts of newborn and adult mice. PMID:26221073

  10. Ventricular tachycardia

    MedlinePlus

    ... of implanting a device called an implantable cardioverter defibrillator (ICD). The ICD is most often implanted in ... tachycardia; V tach; Tachycardia - ventricular Images Implantable cardioverter-defibrillator References Olgin JE, Zipes DP. Specific Arrhythmias: Diagnosis ...

  11. Ventricular fibrillation

    MedlinePlus

    ... Fibrillation is an uncontrolled twitching or quivering of muscle fibers (fibrils). When it occurs in the lower chambers of the heart, it is called ventricular fibrillation. During ... the heart muscle does not get enough oxygen for any reason. ...

  12. A novel, voltage-dependent nonselective cation current activated by insulin in guinea pig isolated ventricular myocytes.

    PubMed

    Zhang, Yin Hua; Hancox, Jules C

    2003-04-18

    Insulin regulates cardiac metabolism and function by targeting metabolic proteins or voltage-gated ion channels. This study provides evidence for a novel, voltage-dependent, nonselective cation channel (NSCC) in the heart. Under voltage clamp at 37 degrees C and with major known conductances blocked, insulin (1 nmol/L to 1 micromol/L) activated an outwardly rectifying current (Iinsulin) in guinea pig ventricular myocytes. Iinsulin could be carried by Cs+, K+, Li+, and Na+ ions but not by NMDG+. It was inhibited by the NSCC blockers gadolinium and SKF96365 but not flufenamic acid. Iinsulin was largely blocked by the insulin receptor tyrosine kinase inhibitor HNMPA-(AM)3 and by the phospholipase C inhibitor U73122 but not by its inactive analogue U73433. Staurosporine, a potent blocker of protein kinase C, did not prevent the activation of Iinsulin. Application of an analogue of diacylglycerol, 1-oleoyl-2-acetyl-sn-glycerol, mimicked the effect of insulin. This activated an outwardly rectifying NSCC that could be carried by Cs+, K+, Li+, or Na+ and that was blocked by gadolinium but not by flufenamic acid or staurosporine. We conclude that the intracellular pathway leading to activation of this novel cardiac NSCC involves phospholipase C, is protein kinase C-independent, and may depend on direct channel activation by diacylglycerol. PMID:12637365

  13. Aeroacoustic theory for noncompact wing-gust interaction

    NASA Technical Reports Server (NTRS)

    Martinez, R.; Widnall, S. E.

    1981-01-01

    Three aeroacoustic models for noncompact wing-gust interaction were developed for subsonic flow. The first is that for a two dimensional (infinite span) wing passing through an oblique gust. The unsteady pressure field was obtained by the Wiener-Hopf technique; the airfoil loading and the associated acoustic field were calculated, respectively, by allowing the field point down on the airfoil surface, or by letting it go to infinity. The second model is a simple spanwise superposition of two dimensional solutions to account for three dimensional acoustic effects of wing rotation (for a helicopter blade, or some other rotating planform) and of finiteness of wing span. A three dimensional theory for a single gust was applied to calculate the acoustic signature in closed form due to blade vortex interaction in helicopters. The third model is that of a quarter infinite plate with side edge through a gust at high subsonic speed. An approximate solution for the three dimensional loading and the associated three dimensional acoustic field in closed form was obtained. The results reflected the acoustic effect of satisfying the correct loading condition at the side edge.

  14. Wilson loops in noncompact U(1) gauge theories at criticality

    SciTech Connect

    Metlitski, Max A.

    2008-04-15

    We study the properties of Wilson loops in three-dimensional noncompact U(1) gauge theories with global Abelian symmetries. We use duality in the continuum and on the lattice to argue that, close to the critical point between the Higgs and Coulomb phases, all correlators of the Wilson loops are periodic functions of the Wilson loop charge, Q. The period depends on the global symmetry of the theory, which determines the magnetic flux carried by the dual particles. For single flavor scalar electrodynamics, the emergent period is Q=1. In the general case of N complex scalars with a U(1){sup N-1} global symmetry, the period is Q=N. We also give some arguments why this phenomenon does not generalize to theories with a full non-Abelian SU(N) symmetry, where no periodicity in Q is expected. Implications for lattice simulations, as well as for physical systems, such as easy-plane antiferromagnets and disordered superfluids, are noted.

  15. Effects of salicylic acid on post-ischaemic ventricular function and purine efflux in isolated mouse hearts.

    PubMed

    Farthing, Don; Gehr, Lynne; Karnes, H Thomas; Sica, Domenic; Gehr, Todd; Larus, Terri; Farthing, Christine; Xi, Lei

    2007-01-01

    Acetyl salicylic acid (aspirin) is one of the most widely used drugs in the world. Various plasma concentrations of aspirin and its predominant metabolite, salicylic acid, are required for its antiarthritic (1.5-2.5 mM), anti-inflammatory (0.5-5.0 mM) or antiplatelet (0.18-0.36 mM) actions. A recent study demonstrated the inhibitory effects of both aspirin and salicylic acid on oxidative phosphorylation and ATP synthesis in isolated rat cardiac mitochondria in a dose-dependent manner (0-10 mM concentration range). In this context, the present study was conducted to determine the effects of salicylic acid on inosine efflux (a potential biomarker of acute cardiac ischaemia) as well as cardiac contractile function in the isolated mouse heart following 20 min of zero-flow global ischaemia. Inosine efflux was found at significantly higher concentrations in ischaemic hearts perfused with Krebs buffer fortified with 1.0 mM salicylic acid compared with those without salicylic acid (12575+/-3319 vs. 1437+/-348 ng ml(-1) min(-1), mean+/-SEM, n=6 per group, p<0.01). These results indicate that 1.0 mM salicylic acid potentiates 8.8-fold ATP nucleotide purine catabolism into its metabolites (e.g. inosine, hypoxanthine). Salicylic acid (0.1 or 1.0 mM) did not appreciably inhibit purine nucleoside phosphorylase (the enzyme converts inosine to hypoxanthine) suggesting the augmented inosine efflux was due to the salicylic acid effect on upstream elements of cellular respiration. Whereas post-ischaemic cardiac function was further depressed by 1.0 mM salicylic acid, perfusion with 0.1 mM salicylic acid led to a remarkable functional improvement despite moderately increased inosine efflux (2.7-fold). We conclude that inosine is a sensitive biomarker for detecting cardiac ischaemia and salicylic acid-induced effects on cellular respiration. However, the inosine efflux level appears to be a poor predictor of the individual post-ischaemic cardiac functional recovery in this ex vivo

  16. Invariant Differential Operators for Non-Compact Lie Groups: Euclidean Jordan Groups or Conformal Lie Groups

    NASA Astrophysics Data System (ADS)

    Dobrev, V. K.

    2013-01-01

    In the present paper we continue the project of systematic construction of invariant differential operators for non-compact semisimple Lie groups. Our starting points is the class of algebras, which we call 'conformal Lie algebras' (CLA), which have very similar properties to the conformal algebras of Minkowski space-time, though our aim is to go beyond this class in a natural way. For this we introduce the new notion of parabolic relation between two non-compact semisimple Lie algebras Script G and Script G' that have the same complexification and possess maximal parabolic subalgebras with the same complexification.

  17. Effects of the Selective Stretch-Activated Channel Blocker GsMtx4 on Stretch-Induced Changes in Refractoriness in Isolated Rat Hearts and on Ventricular Premature Beats and Arrhythmias after Coronary Occlusion in Swine

    PubMed Central

    Barrabés, José A.; Inserte, Javier; Agulló, Luis; Rodríguez-Sinovas, Antonio; Alburquerque-Béjar, Juan J.; Garcia-Dorado, David

    2015-01-01

    Mechanical factors may contribute to ischemic ventricular arrhythmias. GsMtx4 peptide, a selective stretch-activated channel blocker, inhibits stretch-induced atrial arrhythmias. We aimed to assess whether GsMtx4 protects against ventricular ectopy and arrhythmias following coronary occlusion in swine. First, the effects of 170-nM GsMtx4 on the changes in the effective refractory period (ERP) induced by left ventricular (LV) dilatation were assessed in 8 isolated rat hearts. Then, 44 anesthetized, open-chest pigs subjected to 50-min left anterior descending artery occlusion and 2-h reperfusion were blindly allocated to GsMtx4 (57 μg/kg iv. bolus and 3.8 μg/kg/min infusion, calculated to attain the above concentration in plasma) or saline, starting 5-min before occlusion and continuing until after reflow. In rat hearts, LV distension induced progressive reductions in ERP (35±2, 32±2, and 29±2 ms at 0, 20, and 40 mmHg of LV end-diastolic pressure, respectively, P<0.001) that were prevented by GsMTx4 (33±2, 33±2, and 32±2 ms, respectively, P=0.002 for the interaction with LV end-diastolic pressure). Pigs receiving GsMtx4 had similar number of ventricular premature beats during the ischemic period as control pigs (110±28 vs. 103±21, respectively, P=0.842). There were not significant differences among treated and untreated animals in the incidence of ventricular fibrillation (13.6 vs. 22.7%, respectively, P=0.696) or tachycardia (36.4 vs. 50.0%, P=0.361) or in the number of ventricular tachycardia episodes during the occlusion period (1.8±0.7 vs. 5.5±2.6, P=0.323). Thus, GsMtx4 administered under these conditions does not suppress ventricular ectopy following coronary occlusion in swine. Whether it might protect against malignant arrhythmias should be tested in studies powered for these outcomes. PMID:25938516

  18. Unusual electrocardiographic presentation of right ventricular myocardial infarction.

    PubMed Central

    Wilson, J M; Kalife, G; Rogers, M; Strickman, N E; Massumi, A

    1996-01-01

    Isolated right ventricular infarction is uncommon, but when it occurs its prompt recognition may alter therapy substantially. Electrocardiographic changes accompanying acute right ventricular infarction are variable and may be difficult to recognize. The case of a 40-year-old man who had right ventricular infarction with unusual electrocardiographic findings is presented. The clinical, hemodynamic, and electrocardiographic findings of right ventricular infarction are discussed. Images PMID:8969034

  19. Intracellular Ca2+ Transient Phase II Can be Assessed by Half-Logistic Function Model in Isolated Aequorin-Injected Mouse Left Ventricular Papillary Muscle

    PubMed Central

    Mizuno, Ju; Otsuji, Mikiya; Arita, Hideko; Hanaoka, Kazuo; Yokoyama, Takeshi

    2013-01-01

    Background Myocardial contraction and relaxation are regulated by increases and decreases in intracellular cytoplasmic calcium (Ca2+) concentration ([Ca2+]i). In previous studies, we found that a half-logistic (h-L) function, which represents a half-curve of a symmetrical sigmoid logistic function with a boundary at the inflection point, curve-fits the first half of the ascending phase (CaTI) and the second half of the descending phase of the [Ca2+]i transient curve (CaTIV) better than a mono-exponential (m-E) function. In the present study, we investigated the potential application of an h-L function to the analysis of the second half of the ascending phase of the [Ca2+]i transient curve (CaTII). Methods The [Ca2+]i transient was measured using the Ca2+-sensitive photoprotein aequorin, which was microinjected into 15 isolated left ventricular (LV) papillary muscles of mice. The observed CaTII data during the time duration from the point corresponding to the maximum of the first-order time derivative of Ca2+ concentration (dCa/dtmax) to the point corresponding to the peak Ca2+ concentration was curve-fitted by the least-squares method using the h-L and m-E function equations. Results The mean correlation coefficient (r) values of the h-L and m-E curve-fits for CaTII were 0.9996 and 0.9984, respectively. The Z transformation of h-L r was larger than that of m-E r (p < 0.0001). H-L residual mean square (RMS) was smaller than m-E RMS (p < 0.001). Conclusions The h-L function tracks the magnitudes and time courses of CaTII more accurately than the m-E function in isolated aequorin-injected mouse LV papillary muscle. Compared with the m-E time constant, the h-L time constant of CaTII is a more reliable index for evaluating the time duration of the change in the increase in [Ca2+]i during the combination of the middle part of the contraction process and the early part of the relaxation process. CaTII can be assessed by the h-L function model in cardiac muscles. The h

  20. Arrhythmogenic Right Ventricular Dysplasia

    MedlinePlus

    MENU Return to Web version Arrhythmogenic Right Ventricular Dysplasia Overview What is arrhythmogenic right ventricular dysplasia? Arrhythmogenic right ventricular dysplasia (say: “uh-rith-mo-jen-ic right ven-trick- ...

  1. On a Mathematical Model with Noncompact Boundary Conditions Describing Bacterial Population

    NASA Astrophysics Data System (ADS)

    Boulanouar, Mohamed

    2013-04-01

    In this work, we are concerned with the well-posedness of a mathematical model describing a maturation-velocity structured bacterial population. Each bacterium is distinguished by its degree of maturity and its maturation velocity. The bacterial mitosis is mathematically described by noncompact boundary conditions. We show that the mathematical model is governed by a positive strongly continuous semigroup.

  2. Prevalence, Patterns, and Clinical Predictors of Left Ventricular Late Gadolinium Enhancement in Patients Undergoing Cardiac Magnetic Resonance Prior to Pulmonary Vein Antral Isolation for Atrial Fibrillation

    PubMed Central

    Nance, John W.; Khurram, Irfan M.; Nazarian, Saman; DeWire, Jane; Calkins, Hugh; Zimmerman, Stefan L.

    2015-01-01

    Abstract Cardiac magnetic resonance (CMR) imaging is increasingly used to evaluate patients with atrial fibrillation (AF) before pulmonary vein antral isolation (PVAI). The purpose of this study was to assess the incidence and pattern of left ventricular (LV) late gadolinium enhancement (LGE) in patients undergoing CMR before PVAI and compare the clinical and demographic differences of patients with and without LV LGE. Clinical and demographic data on 62 patients (mean age 61 ± 7.9, 69% male) undergoing CMR before PVAI for AF were collected. Two observers, masked to clinical histories, independently recorded the prevalence, extent (number of myocardial segments), and pattern (subendocardial, midmyocardial, or subepicardial) of LV LGE in each patient. Clinical and demographic predictors of LV LGE were determined using logistic regression. Twenty-three patients (37%) demonstrated LV LGE affecting a mean of 3.0 ± 2.1 myocardial segments. There was no difference in LV ejection fraction between patients with and without LGE, and most (65%) patients with LGE had normal wall motion. Only age (P = 0.04) and a history of congestive heart failure (P = .03) were statistically significant independent predictors of LGE. The most common LGE pattern was midmyocardial, seen in 17 of 23 (74%) patients. Only 4 of 23 (17%) patients had LGE in an “expected” pattern based on clinical history. Of the remaining 19 patients, 4 had known congestive heart failure, 5 nonischemic cardiomyopathy, 4 known coronary artery disease, and 2 prior aortic valve replacement. Six of 23 (26%) patients had no known coronary artery, valvular, or myocardial disease. There is a high prevalence of unexpected LV scar in patients undergoing CMR before PVAI for AF, with most patients demonstrating a nonischemic pattern of LV LGE and no wall motion abnormalities (ie, subclinical disease). The high prevalence of unexpected LGE in these patients may argue for CMR as the modality of choice for

  3. Usefulness of Fragmented QRS Complex to Predict Arrhythmic Events and Cardiovascular Mortality in Patients With Noncompaction Cardiomyopathy.

    PubMed

    Cetin, Mehmet Serkan; Ozcan Cetin, Elif Hande; Canpolat, Ugur; Cay, Serkan; Topaloglu, Serkan; Temizhan, Ahmet; Aydogdu, Sinan

    2016-05-01

    We aimed to evaluate the prevalence and prognostic role of fragmented QRS complex (fQRS) in predicting arrhythmic events and cardiovascular mortality in patients with noncompaction cardiomyopathy (NCC). A total of 88 patients (64.8% men, mean age 38.6 ± 17.7 years) with the diagnosis of NCC were enrolled. Median follow-up time was 42.4 months. The fQRS was defined as the presence of ≥1 additional R wave (R') or notch on the R/S waves in ≥2 contiguous leads representing anterior (V1 to V5), inferior (II, III, and aVF), or lateral (I, aVL, and V6) myocardial segments. Compared to patients without fQRS group, patients with fQRS (fQRS (+) group) showed higher rates for total arrhythmic events, ventricular tachycardia, bradyarrhythmia requiring pacemaker, sudden cardiac death, cardiovascular mortality, and all-cause mortality. The cut-off point of ≥3 leads for the fQRS was the optimal point discriminating an arrhythmic event and cardiovascular mortality. In Kaplan-Meier survival analysis, total arrhythmic events and cardiovascular mortality occurred more frequently in the fQRS (+) group. In multivariate Cox proportional hazard regression analysis, after adjusting for other confounding factors, the presence of fQRS were found to be as an independent predictor of arrhythmic events (hazard ratio 3.850, 95% CI 1.062 to 9.947, p = 0.002) and cardiovascular mortality (hazard ratio 2.719, 95% CI 1.494 to 9.262, p = 0.005). In conclusion, the presence of fQRS complex, as a simple and feasible electrocardiographic marker, seems to be a novel predictor of arrhythmic events and cardiovascular mortality in patients with NCC. This simple parameter may be used in identifying patients at high risk for arrhythmic events and so individualization of specific therapies can be applied. PMID:26979479

  4. Isolation of cardiac myosin light-chain isotypes by chromatofocusing. Comparison of human cardiac atrial light-chain 1 and foetal ventricular light-chain 1.

    PubMed

    Vincent, N D; Cummins, P

    1985-04-01

    Cardiac myosin light chain isotypes have been resolved using chromatofocusing, a new preparative column chromatographic technique. The method relies on production of narrow-range, shallow and stable pH gradients using ion-exchange resins and buffers with even buffering capacity over the required pH range. Light chains were resolved in order of decreasing isoelectric point in the pH range 5.2-4.5. Gradients of delta pH = 0.004-0.006/ml elution volume were achieved which were capable of resolving light chains with isoelectric point differences of only 0.03. Analytical isoelectric focusing of light chains in polyacrylamide gels could be used to predict the results of preparative chromatofocusing for method development. Chromatofocusing was capable of resolving human and bovine cardiac light chain 1 and 2 subunits, atrial (ALC) and ventricular (VLC) light chain isotypes and homologous VLC-2 and VLC-2* light chains. The technique was used to purify and resolve the human foetal ventricular light chain 1 (FLC-1) from adult ventricular light chain 1 (VLC-1) present in foetal ventricles and the atrial light chain 1 (ALC-1) in adult atria. Comparative peptide mapping studies and amino acid analyses were carried out on FLC-1 and ALC-1. No differences were detected between FLC-1 and ALC-1 using three different proteases and amino acid compositions were similar with the exception of glycine content. The studies indicate that FLC-1 and ALC-1 are homologous, and possibly identical, light chains. Comparison of human FLC-1/ALC-1 with VLC-1 suggested marked structural and chemical differences in these light chain isotypes, in particular in the contents of methionine, proline, lysine and alanine residues. Differences in the contents of these residues were also apparent in the corresponding bovine atrial and ventricular light chains [Wikman-Coffelt, J. & Srivastava, S. (1979) FEBS Lett. 106, 207-212]. The latter three residues are known to be rich in the N-termini of cardiac and

  5. Coordinating cardiomyocyte interactions to direct ventricular chamber morphogenesis.

    PubMed

    Han, Peidong; Bloomekatz, Joshua; Ren, Jie; Zhang, Ruilin; Grinstein, Jonathan D; Zhao, Long; Burns, C Geoffrey; Burns, Caroline E; Anderson, Ryan M; Chi, Neil C

    2016-06-30

    Many organs are composed of complex tissue walls that are structurally organized to optimize organ function. In particular, the ventricular myocardial wall of the heart comprises an outer compact layer that concentrically encircles the ridge-like inner trabecular layer. Although disruption in the morphogenesis of this myocardial wall can lead to various forms of congenital heart disease and non-compaction cardiomyopathies, it remains unclear how embryonic cardiomyocytes assemble to form ventricular wall layers of appropriate spatial dimensions and myocardial mass. Here we use advanced genetic and imaging tools in zebrafish to reveal an interplay between myocardial Notch and Erbb2 signalling that directs the spatial allocation of myocardial cells to their proper morphological positions in the ventricular wall. Although previous studies have shown that endocardial Notch signalling non-cell-autonomously promotes myocardial trabeculation through Erbb2 and bone morphogenetic protein (BMP) signalling, we discover that distinct ventricular cardiomyocyte clusters exhibit myocardial Notch activity that cell-autonomously inhibits Erbb2 signalling and prevents cardiomyocyte sprouting and trabeculation. Myocardial-specific Notch inactivation leads to ventricles of reduced size and increased wall thickness because of excessive trabeculae, whereas widespread myocardial Notch activity results in ventricles of increased size with a single-cell-thick wall but no trabeculae. Notably, this myocardial Notch signalling is activated non-cell-autonomously by neighbouring Erbb2-activated cardiomyocytes that sprout and form nascent trabeculae. Thus, these findings support an interactive cellular feedback process that guides the assembly of cardiomyocytes to morphologically create the ventricular myocardial wall and more broadly provide insight into the cellular dynamics of how diverse cell lineages organize to create form. PMID:27357797

  6. A 5D noncompact and non Ricci flat Kaluza-Klein Cosmology

    NASA Astrophysics Data System (ADS)

    Darabi, F.

    2009-03-01

    A model universe is proposed in the framework of 5D noncompact Kaluza-Klein cosmology which is not Ricci flat. The 4D part as the Robertson-Walker metric is coupled to conventional perfect fluid, and its extra-dimensional part is coupled to a dark pressure through a scalar field. It is shown that neither early inflation nor current acceleration of the 4D universe would happen if the nonvacuum states of the scalar field would contribute to 4D cosmology.

  7. a 5d Noncompact Kaluza-Klein Cosmology in the Presence of Null Perfect Fluid

    NASA Astrophysics Data System (ADS)

    Farajollahi, Hossein; Amiri, Hamed

    For the description of the early inflation and acceleration expansion of the universe that are compatible with observational data, the 5D noncompact Kaluza-Klein cosmology is investigated. It is proposed that the 5D space is filled with a null perfect fluid, resulting in a perfect fluid in a 4D universe, plus one along the fifth dimension. By analyzing the reduced field equations for the flat FRW model, we show the early inflationary behavior and the current acceleration of the universe.

  8. QED{sub 3} on a space-time lattice: Compact versus noncompact formulation

    SciTech Connect

    Fiore, R.; Giudice, P.; Giuliano, D.; Marmottini, D.; Papa, A.; Sodano, P.

    2005-11-01

    We study quantum electrodynamics in a (2+1)-dimensional space-time with two flavors of dynamical fermions by numerical simulations on the lattice. We discretize the theory using both the compact and the noncompact formulations and analyze the behavior of the chiral condensate and of the monopole density in the finite lattice regime as well as in the continuum limit. By comparing the results obtained with the two approaches, we draw some conclusions about the possible equivalence of the two lattice formulations in the continuum limit.

  9. Percutaneous left ventricular restoration.

    PubMed

    Ige, Mobolaji; Al-Kindi, Sadeer G; Attizzani, Guilherme; Costa, Marco; Oliveira, Guilherme H

    2015-04-01

    The ventricular partitioning device known as Parachute is the first and only percutaneously implantable device aimed at restoration of normal left ventricular geometry in humans. Since its conception, this technology has undergone extensive animal and human testing, with proved feasibility and safety, and is currently being studied in a pivotal randomized clinical trial. This article discusses ventricular remodeling and therapies attempted in the past, details the components of the ventricular partitioning device, describes the implanting technique, and reviews the most current experience of this device in humans. PMID:25834974

  10. Classification of Invariant Differential Operators for Non-Compact Lie Algebras via Parabolic Relations

    NASA Astrophysics Data System (ADS)

    Dobrev, V. K.

    2014-05-01

    In the present paper we review the progress of the project of classification and construction of invariant differential operators for non-compact semisimple Lie groups. Our starting points is the class of algebras, which we called earlier 'conformal Lie algebras' (CLA), which have very similar properties to the conformal algebras of Minkowski space-time, though our aim is to go beyond this class in a natural way. For this we introduced recently the new notion of parabolic relation between two non-compact semisimple Lie algebras G and G' that have the same complexification and possess maximal parabolic subalgebras with the same complexification. Thus, we consider the exceptional algebra E7(7) which is parabolically related to the CLA E7(-25). Other interesting examples are the orthogonal algebras so(p, q) all of which are parabolically related to the conformal algebra so(n, 2) with p + q = n + 2, the parabolic subalgebras including the Lorentz subalgebra so(n - 1,1) and its analogs so(p - 1, q - 1). Further we consider the algebras sl(2n, Bbb R) and for n = 2k the algebras su* (4k) which are parabolically related to the CLA su(n,n). Further we consider the algebras sp(r,r) which are parabolically related to the CLA sp(2r, Bbb R). We consider also E6(6) and E6(2) which are parabolically related to the hermitian symmetric case E6(-14),

  11. [Treatment of ventricular tachycardia].

    PubMed

    Iturralde Torres, P

    2001-01-01

    Evaluation and management of postinfarct ventricular tachycardia has changed dramatically in the past two decades. The introduction of the implantable cardioverter defibrillator has played a major role in this change, alternating both, the purpose of the patients evaluation and treatment options. Episodes of sustained ventricular tachycardia can occur in a variety of clinical settings; the most common of which is the patient who has suffered a myocardial infarction. In this paper, I explore the causes and effects of some of these changes and review current strategies, specially the radiofrequency catheter ablation, for the management of the patient with postinfarct ventricular tachycardia. PMID:11565352

  12. The index theory on non-compact manifolds with proper group action

    NASA Astrophysics Data System (ADS)

    Braverman, Maxim

    2015-12-01

    We construct a regularized index of a generalized Dirac operator on a complete Riemannian manifold endowed with a proper action of a unimodular Lie group. We show that the index is preserved by a certain class of non-compact cobordisms and prove a gluing formula for the regularized index. The results of this paper generalize our previous construction of index for compact group action and the recent paper of Hochs and Mathai who studied the case of a Hamiltonian action on a symplectic manifold. As an application of the cobordism invariance of the index we give an affirmative answer to a question of Hochs and Mathai about the independence of the Hochs-Mathai quantization of the metric, connection and other choices.

  13. Cardiac involvement of primary hyperoxaluria accompanied by non-compaction cardiomyopathy and patent ductus arteriosus.

    PubMed

    Arat, Nurcan; Akyıldız, Murat; Tellioğlu, Gürkan; Tokat, Yaman

    2015-04-01

    Primary hyperoxaluria is a rare hereditary metabolic disorder resulting in accumulation of calcium oxalate in visceral organs, including the heart. We report a 19-year-old male with non- compaction cardiomyopathy combined with patent ductus arteriosus awaiting combined liver-kidney transplantation for primary hyperoxaluria. After surgical closure of the patent ductus arteriosus, the patient underwent a successful renal and subsequent liver transplantation. The presence of hypertrophic cardiomyopathy in hyperoxaluria patients has been reported before, but this is the first report of non-compaction myocardium with patent ductus arteriosus in a patient with primary hyperoxaluria. At the third month after combined liver and renal transplantation, improvement in cardiac functions were observed. Primary hyperoxaluria is a clinical entity to be taken into consideration in differential diagnosis of hypertrophied myocardium with high myocardial echocardiographic intensity. In cases of hyperoxaluria, additional congenital abnormalities may complicate the clinical picture. PMID:25906003

  14. Noncompact lattice QED with two charges: Phase diagram and renormalization group flow

    SciTech Connect

    Ali Khan, A.

    1996-06-01

    The phase diagram of noncompact lattice QED in four dimensions with staggered fermions of charges 1 and {minus}1/2 is investigated. The renormalized charges are determined and found to be in agreement with perturbation theory. This is an indication that there is no continuum limit with nonvanishing renormalized gauge coupling, and that the theory has a validity bound for every finite value of the renormalized coupling. The renormalization group flow of the charges is investigated and an estimate for the validity bound as a function of the cutoff is obtained. Generalizing this estimate to all fermions in the standard model, it is found that a cutoff at the Planck scale implies that {alpha}{sub {ital R}} has to be less than 1/80. Because of spontaneous chiral symmetry breaking, strongly bound fermion-antifermion composite states are generated. Their spectrum is discussed. {copyright} {ital 1996 The American Physical Society.}

  15. Invariant differential operators for non-compact Lie algebras parabolically related to conformal Lie algebras

    NASA Astrophysics Data System (ADS)

    Dobrev, V. K.

    2013-02-01

    In the present paper we continue the project of systematic construction of invariant differential operators for non-compact semisimple Lie groups. Our starting points is the class of algebras, which we call 'conformal Lie algebras' (CLA), which have very similar properties to the conformal algebras of Minkowski space-time, though our aim is to go beyond this class in a natural way. For this we introduce the new notion of parabolic relation between two non-compact semisimple Lie algebras G and G ' that have the same complexification and possess maximal parabolic subalgebras with the same complexification. Thus, we consider the exceptional algebra E 7(7) which is parabolically related to the CLA E 7(-25) , the parabolic subalgebras including E 6(6) and E 6(-26). Other interesting examples are the orthogonal algebras so(p, q) all of which are parabolically related to the conformal algebra so( n, 2) with p + q = n + 2, the parabolic subalgebras including the Lorentz subalgebra so( n - 1, 1) and its analogs so( p - 1, q - 1). We consider also E6(6) and E6(2) which are parabolically related to the hermitian symmetric case E6(-14) , the parabolic subalgebras including real forms of sl(6). We also give a formula for the number of representations in the main multiplets valid for CLAs and all algebras that are parabolically related to them. In all considered cases we give the main multiplets of indecomposable elementary representations including the necessary data for all relevant invariant differential operators. In the case of so( p, q) we give also the reduced multiplets. We should stress that the multiplets are given in the most economic way in pairs of shadow fields. Furthermore we should stress that the classification of all invariant differential operators includes as special cases all possible conservation laws and conserved currents, unitary or not.

  16. Cardiac ventricular aneurysm

    PubMed Central

    Harley, Hugh R. S.

    1969-01-01

    A case of successful excision of a ventricular aneurysm due to myocardial infarction is presented. The aetiology, incidence, pathogenesis, pathology, clinical features, and diagnosis of the condition are discussed. An account is given of the haemodynamic upset caused by aneurysms of the ventricle. The prognosis of untreated aneurysms is discussed. Although there is difference of opinion, it is concluded that a ventricular aneurysm adversely affects the prognosis after myocardial infarction. The indications for, and the mortality and results of, resection of ventricular aneurysms are discussed. The conclusion is drawn that persistent cardiac failure and angina can be relieved and the risk of systemic embolism reduced by the excision of expansile ventricular aneurysms of a fibrous nature. It is possible that excision may also reduce the incidence of subsequent acute myocardial infarction. Images PMID:5821618

  17. Quantum reference frames associated with noncompact groups: The case of translations and boosts and the role of mass

    NASA Astrophysics Data System (ADS)

    Smith, Alexander R. H.; Piani, Marco; Mann, Robert B.

    2016-07-01

    Quantum communication without a shared reference frame or the construction of a relational quantum theory requires the notion of a quantum reference frame. We analyze aspects of quantum reference frames associated with noncompact groups, specifically, the group of spatial translations and Galilean boosts. We begin by demonstrating how the usually employed group average, used to dispense of the notion of an external reference frame, leads to unphysical states when applied to reference frames associated with noncompact groups. However, we show that this average does lead naturally to a reduced state on the relative degrees of freedom of a system, which was previously considered by Angelo et al. [J. Phys. A: Math. Theor. 44, 145304 (2011), 10.1088/1751-8113/44/14/145304]. We then study in detail the informational properties of this reduced state for systems of two and three particles in Gaussian states.

  18. Right ventricular lead ring capture in sequential biventricular pacing with pseudo-bipolar left ventricular lead configuration: an unwanted effect.

    PubMed

    Satish, Oruganti Sai; Yeh, Kuan-Hung; Wen, Ming-Shien; Wang, Chun-Chieh

    2007-01-01

    We report here on three patients who underwent biventricular pacing (BVP) for severe heart failure and the problems encountered with pseudo-bipolar left ventricular (LV) lead configuration. With this configuration, right ventricular anode capture with simultaneous biventricular stimulation was noted at higher output during the isolated LV pacing mode in these patients, which forced us to program the LV pacing to unipolar configuration in one patient. The implication of this phenomenon in sequential BVP therapy is discussed. PMID:17596008

  19. Half-Logistic Function Model for First Half of Descending Phase of Cardiomyocyte Cytoplasmic Ca2+ Concentration ([Ca2+]i)-Time Curve (CaTCIII) in Isolated Aequorin-Injected Mouse Left Ventricular Papillary Muscle

    PubMed Central

    Mizuno, Ju; Otsuji, Mikiya; Yokoyama, Takeshi; Arita, Hideko; Hanaoka, Kazuo

    2016-01-01

    Background Myocardial contraction and relaxation are regulated by increases and decreases in cytoplasmic calcium concentration ([Ca2+]i). In previous studies, we found that a half-logistic (h-L) function, which represents a half-curve of a symmetrical sigmoid logistic function with a boundary at the inflection point, curve-fits the first half of the ascending phase and the second half of the descending phase of the [Ca2+]i transient curve better than a mono-exponential (m-E) function. In the present study, we investigated the potential application of an h-L function to analyse the first half of the descending phase of CaTC (CaTCIII). Methods The [Ca2+]i was measured using the Ca2+-sensitive aequorin, which was microinjected into 15 isolated mouse left ventricular (LV) papillary muscles. The observed CaTCIII data in the interval from the point corresponding to the peak [Ca2+]i to the point corresponding to dCa/dtmin was curve-fitted using the h-L and m-E function equations by the least-squares method. Results The mean correlation coefficient (r) values of the h-L and m-E function best curve-fits for 11 CaTCIIIs were 0.9986 and 0.9982, respectively. The Z transformation of h-L r (3.64 ± 0.45) was larger than that of m-E r (3.50 ± 0.33) (p < 0.05). Conclusions The h-L function can evaluate most CaTCIIIs more accurately than the m-E function in isolated aequorin-injected mouse LV papillary muscle. The three calculated h-L parameters i.e., amplitude constant, time constant, and non-zero asymptote, are more reliable indices than m-E for evaluating the magnitude and time course of the change in the decrease in [Ca2+]i. PMID:27122933

  20. Inverse scattering theory: Inverse scattering series method for one dimensional non-compact support potential

    SciTech Connect

    Yao, Jie; Lesage, Anne-Cécile; Hussain, Fazle; Bodmann, Bernhard G.; Kouri, Donald J.

    2014-12-15

    The reversion of the Born-Neumann series of the Lippmann-Schwinger equation is one of the standard ways to solve the inverse acoustic scattering problem. One limitation of the current inversion methods based on the reversion of the Born-Neumann series is that the velocity potential should have compact support. However, this assumption cannot be satisfied in certain cases, especially in seismic inversion. Based on the idea of distorted wave scattering, we explore an inverse scattering method for velocity potentials without compact support. The strategy is to decompose the actual medium as a known single interface reference medium, which has the same asymptotic form as the actual medium and a perturbative scattering potential with compact support. After introducing the method to calculate the Green’s function for the known reference potential, the inverse scattering series and Volterra inverse scattering series are derived for the perturbative potential. Analytical and numerical examples demonstrate the feasibility and effectiveness of this method. Besides, to ensure stability of the numerical computation, the Lanczos averaging method is employed as a filter to reduce the Gibbs oscillations for the truncated discrete inverse Fourier transform of each order. Our method provides a rigorous mathematical framework for inverse acoustic scattering with a non-compact support velocity potential.

  1. Right Ventricular Myxoma.

    PubMed

    Vadivelmurugan, S; Senthamarai; Sakthimohan; Janarthanan; Balanayagam; Anand, Vijay; Venkateswaran, K J; Ramkumar; Selvaraj

    2015-10-01

    We report a case of 30 year female who presented with complaints of intermittent chest pain and breathlessness for 8 months, Diagnosed to have right ventricular mass protruding into main pulmonary artery during each systole. The mass was completely excised. Histopathological examination showed myxoma. PMID:27608701

  2. Noninvasive mapping of ventricular arrhythmias.

    PubMed

    Shah, Ashok J; Lim, Han S; Yamashita, Seigo; Zellerhoff, Stephan; Berte, Benjamin; Mahida, Saagar; Hooks, Darren; Aljefairi, Nora; Derval, Nicolas; Denis, Arnaud; Sacher, Frédéric; Jais, Pierre; Dubois, Rémi; Hocini, Meleze; Haissaguerre, Michel

    2015-03-01

    Several decades of research has led to the development of a 252-lead electrocardiogram-based three-dimensional imaging modality to refine noninvasive diagnosis and improve the management of heart rhythm disorders. This article reviews the clinical potential of this noninvasive mapping technique in identifying the sources of electrical disorders and guiding the catheter ablation of ventricular arrhythmias (premature ventricular beats and ventricular tachycardia). The article also briefly refers to the noninvasive electrical imaging of the arrhythmogenic ventricular substrate based on the electrophysiologic characteristics of postinfarction ventricular myocardium. PMID:25784026

  3. Ventricular Tachycardias: Characteristics and Management.

    PubMed

    Baldzizhar, Aksana; Manuylova, Ekaterina; Marchenko, Roman; Kryvalap, Yury; Carey, Mary G

    2016-09-01

    Ventricular tachycardias include ventricular tachycardia, ventricular fibrillation, and torsades de pointes; although these rhythms may be benign and asymptomatic, others may be life threatening and lead to increased morbidity and mortality. To optimize patient outcomes, ventricular tachycardias need to be rapidly diagnosed and managed, and often the electrocardiogram (ECG) is the first and only manifestation of a cardiac defect. Understanding of the initial electrocardiographic pattern and subsequent changes can lead to early intervention and an improved outcome. This article describes mechanisms, ECG characteristics, and management of ventricular tachycardias. PMID:27484660

  4. Transcatheter device closure of pseudoaneurysms of the left ventricular wall: An emerging therapeutic option.

    PubMed

    Madan, Tarun; Juneja, Manish; Raval, Abhishek; Thakkar, Bhavesh

    2016-02-01

    Left ventricular pseudoaneurysm is a rare but serious complication of acute myocardial infarction and cardiac surgery. While surgical intervention is the conventional therapeutic option, transcatheter closure can be considered in selected patients with suitable morphology of the pseudoaneurysm. We report a case of successful transcatheter closure of a left ventricular pseudoaneurysm orifice and isolation of the sac using an Amplatzer septal occluder. PMID:26852302

  5. Deficiency in the mouse mitochondrial adenine nucleotide translocator isoform 2 gene is associated with cardiac noncompaction.

    PubMed

    Kokoszka, Jason E; Waymire, Katrina G; Flierl, Adrian; Sweeney, Katelyn M; Angelin, Alessia; MacGregor, Grant R; Wallace, Douglas C

    2016-08-01

    The mouse fetal and adult hearts express two adenine nucleotide translocator (ANT) isoform genes. The predominant isoform is the heart-muscle-brain ANT-isoform gene 1 (Ant1) while the other is the systemic Ant2 gene. Genetic inactivation of the Ant1 gene does not impair fetal development but results in hypertrophic cardiomyopathy in postnatal mice. Using a knockin X-linked Ant2 allele in which exons 3 and 4 are flanked by loxP sites combined in males with a protamine 1 promoter driven Cre recombinase we created females heterozygous for a null Ant2 allele. Crossing the heterozygous females with the Ant2(fl), PrmCre(+) males resulted in male and female ANT2-null embryos. These fetuses proved to be embryonic lethal by day E14.5 in association with cardiac developmental failure, immature cardiomyocytes having swollen mitochondria, cardiomyocyte hyperproliferation, and cardiac failure due to hypertrabeculation/noncompaction. ANTs have two main functions, mitochondrial-cytosol ATP/ADP exchange and modulation of the mitochondrial permeability transition pore (mtPTP). Previous studies imply that ANT2 biases the mtPTP toward closed while ANT1 biases the mtPTP toward open. It has been reported that immature cardiomyocytes have a constitutively opened mtPTP, the closure of which signals the maturation of cardiomyocytes. Therefore, we hypothesize that the developmental toxicity of the Ant2 null mutation may be the result of biasing the cardiomyocyte mtPTP to remain open thus impairing cardiomyocyte maturation and resulting in cardiomyocyte hyperproliferation and failure of trabecular maturation. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:27048932

  6. Anger and ventricular arrhythmias

    PubMed Central

    Lampert, Rachel

    2011-01-01

    Purpose of review Although anecdotal evidence has long suggested links between emotion and ventricular arrhythmia, more recent studies have prospectively demonstrated the arrhythmogenic effects of anger, as well as mechanisms underlying these effects. Recent findings Epidemiological studies reveal that psychological stress increases sudden death, as well as arrhythmias, in patients with implantable cardioverter-defibrillators, in populations during emotionally devastating disasters such as earthquake or war. Diary-based studies confirm that anger and other negative emotions can trigger potentially lethal ventricular arrhythmias. Anger alters electrophysiological properties of the myocardium, including T-wave alternans, a measure of heterogeneity of repolarization, suggesting one mechanistic link between emotion and arrhythmia. Pilot studies of behavioral interventions have shown promise in decreasing arrhythmias in patients with implantable cardioverter-defibrillators. Summary Anger and other strong emotions can trigger polymorphic, potentially life-threatening ventricular arrhythmias in vulnerable patients. Through autonomic changes including increased sympathetic activity and vagal withdrawal, anger leads to increases in heterogeneity of repolarization as measured by T-wave alternans, known to be associated with arrhythmogenesis, as well as increasing inducibility of arrhythmia. Further delineation of mechanisms linking anger and arrhythmia, and of approaches to decrease the detrimental effects of anger and other negative emotions on arrhythmogenesis, are important areas of future investigation. PMID:19864944

  7. Electrocardiogram in corrected transposition of the great vessels of the bulbo-ventricular inversion type

    PubMed Central

    Fernández, F.; Laurichesse, J.; Scebat, L.; Lenègre, J.

    1970-01-01

    Twenty cases of corrected transposition of the great vessels of the bulbo-ventricular inversion type, either lone or combined with other intracardiac anomalies, were analysed. Rhythm and/or atrio-ventricular conduction disturbances were common to all groups of cases. QRS pattern changes were found to be related both to ventricular inversion and to ventricular hypertrophy. Isolated corrected transposition and corrected transposition with systemic ventriculo-atrial regurgitation give rise to tracings suggestive of systemic ventricular hypertrophy. Corrected transposition of the great vessels with pulmonary stenosis or pulmonary artery hypertension is usually accompanied by the electrocardiographic signs of a venous-ventricular hypertrophy, with a characteristic inversion of the normal praecordial pattern. The conventional criteria of ventricular hypertrophy may be applied in corrected transposition of the great vessels but are less reliable than in cases without ventricular inversion. The so-called electrocardiographic pattern of `ventricular inversion' in this anomaly is related not only to the inverted position of the ventricles but to a greater extent to the predominant, anatomically left, venous-ventricular hypertrophy which re-establishes the normal weight ratio between the anatomically right and anatomically left ventricles. Images PMID:5440512

  8. Fat in the ventricular septum

    PubMed Central

    Donaldson, Erin E.; Ko, Jong Mi; Kuiper, Johannes J.; Chamogeorgakis, Themistokles

    2014-01-01

    Described herein is a 68-year-old man who underwent cardiac transplantation for severe chronic heart failure resulting from ischemic cardiomyopathy. Examination of the excised heart showed not only extensive left ventricular scarring but also a huge collection of adipose tissue in the subepicardial region and surprisingly also in the ventricular septum. The finding of fat in the ventricular septum is extremely rare and prompted this report. PMID:24982572

  9. Imaging for the Diagnosis of an Unusual Case of Left Ventricular Aneurysm

    SciTech Connect

    Russo, G. Sarais, C.; Corbetti, F.; Ramondo, A.; Daliento, L.

    2005-04-15

    An isolated ventricular diverticulum in an adult patient investigated for chest pain is reported. An exhaustive diagnosis was obtained by different means and complementary imaging techniques such as echocardiography, cardiovascular magnetic resonance imaging and cineangiography.

  10. [Electrovectocardiographic manifestations of left ventricular and biventricular growth].

    PubMed

    de Micheli, A; Medrano, G A

    1988-01-01

    The basic criteria for the electrical diagnosis of left ventricular and biventricular enlargements are discussed on the basis of the myocardial depolarization and repolarization sequence. Left ventricular dilatation secondary to isolated diastolic overloading increases the manifestation of the main vectors resulting from the activation of this ventricle. These changes reflect the proximity of the left ventricular walls to the exploring electrodes. The above mentioned vectors appear as tall R waves and wide ventricular curves with counterclockwise rotation on the three planes. If the diastolic overload is a isolated phenomenon, T waves are positive and asymmetric on the left leads while the T loop, of secondary type, is concordant in its orientation with the R loop. This fact is due to a prolonged duration of the repolarization phase of the left ventricle. Global left ventricular hypertrophy produced by a sustained systolic overloading increases the magnitude and manifestation of all the vectors resulting from the depolarization of this ventricle (I, II l, III l) owing to the prolonged duration of the corresponding activation fronts. When LBBB is also present, the first septal vector is not evident. In extreme degrees of the systolic overload, the T wave is inverted and shows morphologic secondary characteristics in left leads, and the T loop opposes the R loop on frontal and horizontal planes. The directional changes of the repolarization fronts of free left ventricular walls can satisfactorily explain these features. Left ventricular hypertrophy of a segmentary type, such as that observed in idiopathic myocardiopathy, generally increases the magnitude and manifestation of septal vector I and II left. When both ventricles are hypertrophied, the electromotive forces originating in the more severely affected heart chamber predominate in electrical records. PMID:2967067

  11. Nonischemic Left Ventricular Scar as a Substrate of Life-Threatening Ventricular Arrhythmias and Sudden Cardiac Death in Competitive Athletes

    PubMed Central

    Zorzi, Alessandro; Perazzolo Marra, Martina; Rigato, Ilaria; De Lazzari, Manuel; Susana, Angela; Niero, Alice; Pilichou, Kalliopi; Migliore, Federico; Rizzo, Stefania; Giorgi, Benedetta; De Conti, Giorgio; Sarto, Patrizio; Serratosa, Luis; Patrizi, Giampiero; De Maria, Elia; Pelliccia, Antonio; Basso, Cristina; Schiavon, Maurizio; Bauce, Barbara; Iliceto, Sabino; Thiene, Gaetano

    2016-01-01

    Background— The clinical profile and arrhythmic outcome of competitive athletes with isolated nonischemic left ventricular (LV) scar as evidenced by contrast-enhanced cardiac magnetic resonance remain to be elucidated. Methods and Results— We compared 35 athletes (80% men, age: 14–48 years) with ventricular arrhythmias and isolated LV subepicardial/midmyocardial late gadolinium enhancement (LGE) on contrast-enhanced cardiac magnetic resonance (group A) with 38 athletes with ventricular arrhythmias and no LGE (group B) and 40 healthy control athletes (group C). A stria LGE pattern with subepicardial/midmyocardial distribution, mostly involving the lateral LV wall, was found in 27 (77%) of group A versus 0 controls (group C; P<0.001), whereas a spotty pattern of LGE localized at the junction of the right ventricle to the septum was respectively observed in 11 (31%) versus 10 (25%; P=0.52). All athletes with stria pattern showed ventricular arrhythmias with a predominant right bundle branch block morphology, 13 of 27 (48%) showed ECG repolarization abnormalities, and 5 of 27 (19%) showed echocardiographic hypokinesis of the lateral LV wall. The majority of athletes with no or spotty LGE pattern had ventricular arrhythmias with a predominant left bundle branch block morphology and no ECG or echocardiographic abnormalities. During a follow-up of 38±25 months, 6 of 27 (22%) athletes with stria pattern experienced malignant arrhythmic events such as appropriate implantable cardiac defibrillator shock (n=4), sustained ventricular tachycardia (n=1), or sudden death (n=1), compared with none of athletes with no or LGE spotty pattern and controls. Conclusions— Isolated nonischemic LV LGE with a stria pattern may be associated with life-threatening arrhythmias and sudden death in the athlete. Because of its subepicardial/midmyocardial location, LV scar is often not detected by echocardiography. PMID:27390211

  12. Right ventricular failure after left ventricular assist device implantation: the need for an implantable right ventricular assist device.

    PubMed

    Furukawa, Kojiro; Motomura, Tadashi; Nosé, Yukihiko

    2005-05-01

    Right ventricular failure after implantation of a left ventricular assist device is an unremitting problem. Consideration of portal circulation is important for reversing liver dysfunction and preventing multiple organ failure after left ventricular assist device implantation. To achieve these objectives, it is imperative to maintain the central venous pressure as low as possible. A more positive application of right ventricular assistance is recommended. Implantable pulsatile left ventricular assist devices cannot be used as a right ventricular assist device because of their structure and device size. To improve future prospects, it is necessary to develop an implantable right ventricular assist device based on a rotary blood pump. PMID:15854212

  13. Electrical injury causing ventricular arrhythmias.

    PubMed Central

    Jensen, P J; Thomsen, P E; Bagger, J P; Nørgaard, A; Baandrup, U

    1987-01-01

    Dangerous or long lasting ventricular arrhythmias developed in three patients who had sustained an electrical injury in which current passed through the thorax. In all three cases there was a delay of 8-12 hours between the injury and the onset of symptoms. The ventricular arrhythmias were severe and long lasting. In two of the three patients, ventricular tachycardia or ventricular fibrillation or both occurred and in one patient ventricular parasystole developed. No enzymatic evidence of myocardial necrosis was found but the results of an endomyocardial biopsy carried out in two of the three patients showed focal myocardial fibrosis and increased numbers of Na, K-pumps. The two patients with ventricular tachycardia became symptom free after appropriate antiarrhythmic treatment and in the third patient ventricular parasystole disappeared spontaneously within two years. Patients sustaining electrical injury in which current passes through the thorax should be monitored electrocardiographically for at least 24 hours, and patients with unexpected arrhythmias should be questioned about previous electrical injury. Images Fig 2 PMID:3566986

  14. Epicardial ventricular tachycardia.

    PubMed

    Garan, Hasan

    2013-12-01

    In ventricular tachycardia (VT) arising in the myocardial tissue, the site of origin may be the endocardium, mid-myocardium or epicardium. The incidence of epicardial origin varies with the underlying heart disease, and is probably not more than 20% in ischemic heart disease and higher in non-ischemic cardiomyopathies. Percutaneous subxiphoid access to the pericardial space has enabled a non-surgical approach to catheter mapping and ablation of epicardial VT. Several algorithms are available for electrocardiographic recognition of epicardial origin. Idiopathic epicardial VTs are rare but may be curable by catheter ablation. The electrophysiologic principles guiding the mapping and ablation of epicardial VTs are similar to those used for endocardial VTs, but the biophysics of energy delivery may be different. Complications of the epicardial approach are also different from those of endocardial ablation, and specific precautions have to be taken to protect the coronary arteries and phrenic nerves and to avoid pericardial tamponade. PMID:24351953

  15. Arrhythmogenic right ventricular cardiomyopathy in a weimaraner

    PubMed Central

    Eason, Bryan D.; Leach, Stacey B.; Kuroki, Keiichi

    2015-01-01

    Arrhythmogenic right ventricular cardiomyopathy (ARVC) was diagnosed postmortem in a weimaraner dog. Syncope, ventricular arrhythmias, and sudden death in this patient combined with the histopathological fatty tissue infiltration affecting the right ventricular myocardium are consistent with previous reports of ARVC in non-boxer dogs. Arrhythmogenic right ventricular cardiomyopathy has not been previously reported in weimaraners. PMID:26483577

  16. Noncompact three-dimensional quantum electrodynamics with N{sub f}=1 and N{sub f}=4

    SciTech Connect

    Hands, S.J.; Kogut, J.B.; Scorzato, L.; Strouthos, C.G.

    2004-09-01

    We present numerical results for noncompact three-dimensional quantum electrodynamics for numbers of flavors N{sub f}=1 and N{sub f}=4. In particular, we address the issue of whether chiral symmetry is spontaneously broken in the continuum limit, and obtain a positive answer for N{sub f}=1, with a dimensionless condensate estimated to be {beta}{sup 2}<{psi}{psi}>{approx_equal}O(10{sup -3}), implying that the critical number of flavors N{sub fc}>1. We also compare the N{sub f}=1 and N{sub f}=4 models by analyzing the transition from strong to weak coupling behavior using an equation of state based on a continuous phase transition. While some qualitative differences emerge, it appears difficult to determine whether N{sub f}=4 lies above or below N{sub fc}.

  17. Left ventricular pseudoaneurysm after perventricular ventricular septal defect device closure.

    PubMed

    Trezzi, Matteo; Kavarana, Minoo N; Hlavacek, Anthony M; Bradley, Scott M

    2014-03-01

    Perventricular ventricular septal defect (VSD) closure has been adopted as a therapeutic option for selected patients with muscular VSDs. This technique may combine some of the advantages of surgical and interventional techniques. Complication rates have been low: only one case of procedure-related left ventricular (LV) pseudoaneurysm has been documented. We report the surgical repair for a LV pseudoaneurysm after perventricular VSD device closure. PMID:24131474

  18. Facts about Ventricular Septal Defect

    MedlinePlus

    ... The size of the ventricular septal defect will influence what symptoms, if any, are present, and whether ... this image. Close Information For... Media Policy Makers Language: English Español (Spanish) File Formats Help: How do ...

  19. Usefulness of ventricular endocardial electric reconstruction from body surface potential maps to noninvasively localize ventricular ectopic activity in patients

    NASA Astrophysics Data System (ADS)

    Lai, Dakun; Sun, Jian; Li, Yigang; He, Bin

    2013-06-01

    As radio frequency (RF) catheter ablation becomes increasingly prevalent in the management of ventricular arrhythmia in patients, an accurate and rapid determination of the arrhythmogenic site is of important clinical interest. The aim of this study was to test the hypothesis that the inversely reconstructed ventricular endocardial current density distribution from body surface potential maps (BSPMs) can localize the regions critical for maintenance of a ventricular ectopic activity. Patients with isolated and monomorphic premature ventricular contractions (PVCs) were investigated by noninvasive BSPMs and subsequent invasive catheter mapping and ablation. Equivalent current density (CD) reconstruction (CDR) during symptomatic PVCs was obtained on the endocardial ventricular surface in six patients (four men, two women, years 23-77), and the origin of the spontaneous ectopic activity was localized at the location of the maximum CD value. Compared with the last (successful) ablation site (LAS), the mean and standard deviation of localization error of the CDR approach were 13.8 and 1.3 mm, respectively. In comparison, the distance between the LASs and the estimated locations of an equivalent single moving dipole in the heart was 25.5 ± 5.5 mm. The obtained CD distribution of activated sources extending from the catheter ablation site also showed a high consistency with the invasively recorded electroanatomical maps. The noninvasively reconstructed endocardial CD distribution is suitable to predict a region of interest containing or close to arrhythmia source, which may have the potential to guide RF catheter ablation.

  20. Ventricular assist devices in pediatrics

    PubMed Central

    Fuchs, A; Netz, H

    2001-01-01

    The implantation of a mechanical circulatory device for end-stage ventricular failure is a possible therapeutic approach in adult and pediatric cardiac surgery and cardiology. The aim of this article is to present mechanical circulatory assist devices used in infants and children with special emphasis on extracorporeal membrane oxygenation, Berlin Heart assist device, centrifugal pump and Medos assist device. The success of long-term support with implantable ventricular assist devices in adults and children has led to their increasing use as a bridge to transplantation in patients with otherwise non-treatable left ventricular failure, by transforming a terminal phase heart condition into a treatable cardiopathy. Such therapy allows rehabilitation of patients before elective cardiac transplantation (by removing contraindications to transplantation mainly represented by organ impairment) or acting as a bridge to recovery of the native left ventricular function (depending on underlying cardiac disease). Treatment may also involve permanent device implantation when cardiac transplantation is contraindicated. Indications for the implantation of assisted circulation include all states of cardiac failure that are reversible within a variable period of time or that require heart transplantation. This article will address the current status of ventricular assist devices by examining historical aspects of its development, current technical issues and clinical features of pediatric ventricular assist devices, including indications and contraindications for support. PMID:22368605

  1. The relationship of left ventricular trabeculation to ventricular function and structure over 9.5 years follow up: the Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Zemrak, Filip; Ahlman, Mark A.; Captur, Gabriella; Mohiddin, Saidi A; Kawel-Boehm, Nadine; Prince, Martin R.; Moon, James C.; Hundley, William G.; Lima, João A.C.; Bluemke, David A; Petersen, Steffen E

    2015-01-01

    Background Left ventricular (LV) trabeculation is highly variable between individuals, is increased in some diseases (e.g. congenital heart disease or cardiomyopathies), but its significance in population representative individuals is unknown. Objectives To determine if excessive LV trabeculation in population representative subjects is associated with preceding changes in cardiac volumes and function. Methods The extent of trabeculation, expressed as the ratio of non-compacted to compacted (NC/C) myocardium was measured for technical reasons on cardiac magnetic resonance (CMR) long-axis cine images in 2742 subjects in the Multi-Ethnic Study of Atherosclerosis (mean age 68.7 years, 52.3% women, 56.4% with hypertension, 16.8% with diabetes) at the exam 5. These were considered in quintiles of trabeculation extent, with quintile 5’s NC/C 2.46 – 5.41. We determined the relationship between maximal NC/C ratio and preceding change (9.5 year between exam 1 and 5) in end-systolic volume indexed to the body surface area (ESVi). Secondary analysis assessed associations between maximal NC/C and preceding changes in end-diastolic volume indexed to the body surface area (EDVi) and ejection fraction (EF). Results Over 9.5 years, ESVi decreased by 1.3 ml/m2, EDVi decreased by 5.1 ml/m2 and EF decreased by 0.6% (p<0.0001). There were no clinically relevant differences in LV volumes and systolic function change between the quintiles of trabeculation extent, even in subjects with the excessive trabeculation. Conclusions Greater extent of and even excessive LV trabeculations measured in end-diastole in asymptomatic population representative individuals appears benign and is not associated with deterioration in left ventricular volumes or function over an almost 10 year period. PMID:25440091

  2. Catheter Ablation of Polymorphic Ventricular Tachycardia and Ventricular Fibrillation

    PubMed Central

    Peichl, Petr

    2013-01-01

    Recently, catheter ablation (CA) has become a therapeutic option to target focal triggers of polymorphic ventricular tachycardia and ventricular fibrillation (VF) in the setting of electrical storm (ES). This strategy was first described in subjects without organic heart disease (i.e. idiopathic VF) and subsequently in other conditions, especially in patients with ischaemic heart disease. In the majority of cases, the triggering focus originates in the ventricular Purkinje system. In patients with Brugada syndrome, besides ablation of focal trigger in the right ventricular outflow tract, modification of a substrate in this region has been described to prevent recurrences of VF. In conclusion, CA appears to be a reasonable strategy for intractable cases of ES due to focally triggered polymorphic ventricular tachycardia and VF. Therefore, early transport of the patient into the experience centre for CA should be considered since the procedure could be in some cases life-saving. Therefore, the awareness of this entity and link to the nearest expert centre are important.

  3. New strategies for ventricular tachycardia and ventricular fibrillation ablation.

    PubMed

    Hooks, Darren A; Berte, Benjamin; Yamashita, Seigo; Mahida, Saagar; Sellal, Jean-Marc; Aljefairi, Nora; Frontera, Antonio; Derval, Nicolas; Denis, Arnaud; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre; Sacher, Frederic

    2015-03-01

    Patients with ventricular tachycardia (VT) and ventricular fibrillation (VF) and no reversible cause are difficult to treat. While implantable defibrillators prolong survival, many patients remain symptomatic due to device shocks and syncope. To address this, there have been recent advances in the catheter ablation of VT and VF. For example, non-invasive imaging has improved arrhythmia substrate characterisation, 3D catheter navigation tools have facilitated mapping of arrhythmia and substrate and ablation catheters have advanced in their ability to deliver effective lesions. However, the long-term success rates of ablation for VT and VF remain modest, with nearly half of treated patients developing recurrence within 2-3 years, and this drives the ongoing innovation in the field. This review focuses on the challenges particular to ablation of life-threatening ventricular arrhythmia, and the strategies that have been recently developed to improve procedural efficacy. Patient sub-groups that illustrate the use of new strategies are described. PMID:25666031

  4. Pediatric ventricular assist devices.

    PubMed

    Adachi, Iki; Burki, Sarah; Zafar, Farhan; Morales, David Luis Simon

    2015-12-01

    The domain of pediatric ventricular assist device (VAD) has recently gained considerable attention. Despite the fact that, historically, the practice of pediatric mechanical circulatory support (MCS) has lagged behind that of adult patients, this gap between the two groups is narrowing. Currently, the Berlin EXCOR VAD is the only pediatric-specific durable VAD approved by the U.S Food and Drug Administration (FDA). The prospective Berlin Heart trial demonstrated a successful outcome, either bridge to transplantation (BTT), or in rare instances, bridge to recovery, in approximately 90% of children. Also noted during the trial was, however, a high incidence of adverse events such as embolic stroke, bleeding and infection. This has incentivized some pediatric centers to utilize adult implantable continuous-flow devices, for instance the HeartMate II and HeartWare HVAD, in children. As a result of this paradigm shift, the outlook of pediatric VAD support has dramatically changed: Treatment options previously unavailable to children, including outpatient management and even destination therapy, have now been becoming a reality. The sustained demand for continued device miniaturization and technological refinements is anticipated to extend the range of options available to children-HeartMate 3 and HeartWare MVAD are two examples of next generation VADs with potential pediatric application, both of which are presently undergoing clinical trials. A pediatric-specific continuous-flow device is also on the horizon: the redesigned Infant Jarvik VAD (Jarvik 2015) is undergoing pre-clinical testing, with a randomized clinical trial anticipated to follow thereafter. The era of pediatric VADs has begun. In this article, we discuss several important aspects of contemporary VAD therapy, with a particular focus on challenges unique to the pediatric population. PMID:26793341

  5. Pediatric ventricular assist devices

    PubMed Central

    Burki, Sarah; Zafar, Farhan; Morales, David Luis Simon

    2015-01-01

    The domain of pediatric ventricular assist device (VAD) has recently gained considerable attention. Despite the fact that, historically, the practice of pediatric mechanical circulatory support (MCS) has lagged behind that of adult patients, this gap between the two groups is narrowing. Currently, the Berlin EXCOR VAD is the only pediatric-specific durable VAD approved by the U.S Food and Drug Administration (FDA). The prospective Berlin Heart trial demonstrated a successful outcome, either bridge to transplantation (BTT), or in rare instances, bridge to recovery, in approximately 90% of children. Also noted during the trial was, however, a high incidence of adverse events such as embolic stroke, bleeding and infection. This has incentivized some pediatric centers to utilize adult implantable continuous-flow devices, for instance the HeartMate II and HeartWare HVAD, in children. As a result of this paradigm shift, the outlook of pediatric VAD support has dramatically changed: Treatment options previously unavailable to children, including outpatient management and even destination therapy, have now been becoming a reality. The sustained demand for continued device miniaturization and technological refinements is anticipated to extend the range of options available to children—HeartMate 3 and HeartWare MVAD are two examples of next generation VADs with potential pediatric application, both of which are presently undergoing clinical trials. A pediatric-specific continuous-flow device is also on the horizon: the redesigned Infant Jarvik VAD (Jarvik 2015) is undergoing pre-clinical testing, with a randomized clinical trial anticipated to follow thereafter. The era of pediatric VADs has begun. In this article, we discuss several important aspects of contemporary VAD therapy, with a particular focus on challenges unique to the pediatric population. PMID:26793341

  6. Molecular mechanisms of ventricular hypoplasia.

    PubMed

    Srivastava, D; Gottlieb, P D; Olson, E N

    2002-01-01

    We have established the beginnings of a road map to understand how ventricular cells become specified, differentiate, and expand into a functional cardiac chamber (Fig. 5). The transcriptional networks described here provide clear evidence that disruption of pathways affecting ventricular growth could be the underlying etiology in a subset of children born with malformation of the right or left ventricle. As we learn details of the precise mechanisms through which the critical factors function, the challenge will lie in devising innovative methods to augment or modify the effects of gene mutations on ventricular development. Because most congenital heart disease likely occurs in a setting of heterozygous, predisposing mutations of one or more genes, modulation of activity of critical pathways in a preventive fashion may be useful in averting disease in genetically susceptible individuals. PMID:12858532

  7. Genetics Home Reference: catecholaminergic polymorphic ventricular tachycardia

    MedlinePlus

    ... for This Page Cerrone M, Napolitano C, Priori SG. Catecholaminergic polymorphic ventricular tachycardia: A paradigm to understand ... on PubMed Central Liu N, Ruan Y, Priori SG. Catecholaminergic polymorphic ventricular tachycardia. Prog Cardiovasc Dis. 2008 ...

  8. Left Ventricular Assist Devices

    PubMed Central

    2004-01-01

    Executive Summary Objective The objective of this health technology policy assessment was to determine the effectiveness and cost-effectiveness of using implantable ventricular assist devices in the treatment of end-stage heart failure. Heart Failure Heart failure is a complex syndrome that impairs the ability of the heart to maintain adequate blood circulation, resulting in multiorgan abnormalities and, eventually, death. In the period of 1994 to 1997, 38,702 individuals in Ontario had a first hospital admission for heart failure. Despite reported improvement in survival, the five-year mortality rate for heart failure is about 50%. For patients with end-stage heart failure that does not respond to medical therapy, surgical treatment or traditional circulatory assist devices, heart transplantation (in appropriate patients) is the only treatment that provides significant patient benefit. Heart Transplant in Ontario With a shortage in the supply of donor hearts, patients are waiting longer for a heart transplant and may die before a donor heart is available. From 1999 to 2003, 55 to 74 people received a heart transplant in Ontario each year. Another 12 to 21 people died while waiting for a suitable donor heart. Of these, 1 to 5 deaths occurred in people under 18 years old. The rate-limiting factor in heart transplant is the supply of donor hearts. Without an increase in available donor hearts, attempts at prolonging the life of some patients on the transplant wait list could have a harmful effect on other patients that are being pushed down the waiting list (knock on effect). LVAD Technology Ventricular assist devices [VADs] have been developed to provide circulatory assistance to patients with end-stage heart failure. These are small pumps that usually assist the damaged left ventricle [LVADs] and may be situated within the body (intracorporeal] or outside the body [extracorporeal). Some of these devices were designed for use in the right ventricle [RVAD] or both

  9. Allicin inhibits transient outward potassium currents in mouse ventricular myocytes

    PubMed Central

    CAO, HONG; HUANG, CONGXIN; WANG, XIN

    2016-01-01

    Allicin is the active constituent of garlic, a widely used spice and food. The remedial properties of garlic have also been extensively researched and it has been demonstrated that allicin is able to inhibit the transient outward potassium current (Ito) in atrial myocytes. However, the direct effect of allicin on Ito in ventricular myocytes has yet to be elucidated. In the present study, the effects of allicin on Ito in ventricular myocytes isolated from mice were investigated, using the whole-cell patch recording technique. The results revealed that Ito current was not significantly suppressed by allicin in the low-dose group (10 µmol/l; P>0.05). However, Ito was significantly inhibited by higher doses of allicin (30, 100 and 300 µmol/l; P<0.05 vs. control; n=6) in a concentration-dependent manner (IC50=41.6 µmol/l). In addition, a high concentration of allicin (≥100 µmol/l) was able to accelerate the voltage-dependent inactivation of Ito in mouse ventricular myocytes. In conclusion, the present study revealed that allicin inhibited the Ito in mouse ventricular myocytes, which may be the mechanism through which allicin exerts its antiarrhythmic effect. PMID:27168824

  10. Two Ti13-oxo-clusters showing non-compact structures, film electrode preparation and photocurrent properties.

    PubMed

    Hou, Jin-Le; Luo, Wen; Wu, Yin-Yin; Su, Hu-Chao; Zhang, Guang-Lin; Zhu, Qin-Yu; Dai, Jie

    2015-12-14

    Two benzene dicarboxylate (BDC) and salicylate (SAL) substituted titanium-oxo-clusters, Ti13O10(o-BDC)4(SAL)4(O(i)Pr)16 (1) and Ti13O10(o-BDC)4(SAL-Cl)4(O(i)Pr)16 (2), are prepared by one step in situ solvothermal synthesis. Single crystal analysis shows that the two Ti13 clusters take a paddle arrangement with an S4 symmetry. The non-compact (non-sphere) structure is stabilized by the coordination of BDC and SAL. Film photoelectrodes are prepared by the wet coating process using the solution of the clusters and the photocurrent response properties of the electrodes are studied. It is found that the photocurrent density and photoresponsiveness of the electrodes are related to the number of coating layers and the annealing temperature. Using ligand coordinated titanium-oxo-clusters as the molecular precursors of TiO2 anatase films is found to be effective due to their high solubility, appropriate stability in solution and hence the easy controllability. PMID:26508128

  11. [Drug-induced ventricular tachycardia].

    PubMed

    Fauchier, J P; Fauchier, L; Babuty, D; Breuillac, J C; Cosnay, P; Rouesnel, P

    1993-05-01

    Certain drugs can induce ventricular tachycardia (VT) by creating reentry, ventricular after potentials or exaggerating the slope of phase 4. These may or may not be symptomatic, sustained or non-sustained and have variable ECG appearances: monomorphic or polymorphic, bidirectional, torsades de pointes. They risk degenerating into ventricular flutter of fibrillation and have been held responsible for the increased mortality observed unexpectedly in some long-term treatments. The drugs responsible are mainly those used in cardiology, probably due to predisposing circumstances (cardiomegaly, cardiac failure, previous severe ventricular arrhythmias, therapeutic associations, metabolic abnormalities). These include primarily the antiarrhythmic drugs (IA, IC, sotalol and bepridil), digitalis, sympathomimetics and phosphodiesterase inhibitors. These complications may be toxic or idiosyncratic, in patients with or without cardiac disease, and may also occur with other drugs: vasodilators and anti-anginal drugs (lidoflazine, vincamine, fenoxedil), psychotropic agents (phenothiazine and imipramine), antimitotics, antimalarials (chloroquine) or antibiotics (erythromycin, pentamidine). The prognosis is severe and the treatment is often difficult which makes prevention, helped by repeated surface ECG (or Holter monitoring), very important with careful assessment of patients at risk. PMID:8267504

  12. Protooncogene expression identifies a transient columnar organization of the forebrain within the late embryonic ventricular zone

    SciTech Connect

    Johnston, J.G.; Van Der Kooy, D. )

    1989-02-01

    Immunocytochemical studies using monoclonal antibodies directed against oncogenic peptides revealed a heterogeneous distribution of the peptides within the ventricular zone of the embryonic day 18 rat forebrain. This sis-, src-, ras-, and myc-encoded peptides were concentrated in the same isolated clusters of 5-25 radial glial cells (also identified by vimentin staining), providing a transient columnar compartmentalization to the ventricular zone. An increased number of ({sup 3}H)thymidine-labeled ventricular zone cells were observed within the protooncogene stained radial glial cell columns as compared to noncolumn areas. The columnar heterogeneity of radial glial cells reveals the mosaicism of the embryonic ventricular zone and the differential proliferation of its cells.

  13. Intracellular recording of in situ ventricular cells during ventricular fibrillation.

    PubMed

    Akiyama, T

    1981-04-01

    Transmembrane action potentials (AP) from ventricular cells during ventricular fibrillation (VF) have not been systematically studied. We have recently developed a motion-compensated micropipette holder that holds a micropipette and moves in synchrony with heart motion. AP of subepicardial ventricular cells were recorded in 14 open-chest anesthetized dogs prior to occlusion (control) of left anterior descending artery (LAD) and during first 10 min of reperfusion-induced VF. During control, characteristics (means +/- SE) of AP are: excitation rate (R), 112 +/- 4 beats/min; resting potential (Vr), -79.3 +/- 1.0 mV; overshoot potential (Vov), 17.9 +/- 1.8 mV; 90% AP duration (APD), 251 +/- 8 ms. During VF, AP from the reperfused areas are: R, 173 +/- 27 beats/min; Vr, -60.6 +/- 2.2 mV; Vov, 3.4 +/- 2.9 mV; APD, 134 +/- 9 ms (significantly different from control at P less than 0.001, except R). During VF, cells from the reperfused areas are made inexcitable with verapamil, but not by tetrodotoxin. In conclusion, during VF accurate AP recording is possible from in situ heart, and subepicardial cells in reperfused areas seem to have AP of slow-channel type. PMID:7223899

  14. Ventricular assist devices: initial orientation

    PubMed Central

    Dave, Hitendu; Lemme, Frithjof; Romanchenko, Olga; Hofmann, Michael; Hübler, Michael

    2013-01-01

    Ventricular assist device (VAD) technology has come from large pulsatile-flow devices with a high rate of technical malfunctions to small continuous flow (cf) devices. Mechanical circulatory support (MCS) systems may be used as short-, mid- or long-term support. Especially if mid- or long-term support is anticipated left VADs (LVADs) have been reported with excellent one and two year survival rates and improved quality of life (QoL). Timing of implantation, patient selection, assessing function of the right ventricular and surgical considerations regarding surgical access side, valve pathology and exit side of the percutaneous lead remain crucial issues for the outcome. In contrast VADs designed for children especially for all age groups, are still underrepresented but increased experience with existing pediatric VADs as well as introduction of second and third generation VADs into in the pediatric age group, offer new perspectives. PMID:23991317

  15. Dabigatran for left ventricular thrombus.

    PubMed

    Kolekar, Satishkumar; Munjewar, Chandrashekhar; Sharma, Satyavan

    2015-01-01

    Male patient in dilated phase of hypertrophic cardiomyopathy had multiple hospitalizations during the past 2 years either due to congestive heart failure, stroke, scar epilepsy, or atrial fibrillation and ventricular tachycardia. Medication included evidence based therapy for heart failure, cordarone and warfarin. Anticoagulation had to be discontinued due to marked fluctuations in INR. Transthoracic Echocardiography (TTE) revealed a mobile mass in the left ventricle. He was treated with Dabigatran 110mg twice a day for 4 months without any bleeding or embolic episode and complete resolution of thrombus. Dabigatran is a reversible direct thrombin inhibitor and currently approved for the prevention of thromboembolic episodes in non-valvar atrial fibrillation. This case demonstrates possible thrombolytic properties of dabigatran in resolution of left ventricular thrombus. PMID:26432747

  16. Different effects of abnormal activation and myocardial disease on left ventricular ejection and filling times

    PubMed Central

    Zhou, Q; Henein, M; Coats, A; Gibson, D

    2000-01-01

    BACKGROUND—Ventricular activation is often abnormal in patients with dilated cardiomyopathy, but its specific effects on timing remain undetermined.
OBJECTIVE—To investigate the use of the ratio of the sum of left ventricular ejection and filling times to the total RR interval (Z ratio) to dissociate the effects of abnormal activation from those of cavity dilatation.
METHODS—Subjects were 20 normal individuals, 11 patients with isolated left bundle branch block (LBBB, QRS duration > 120 ms), 17 with dilated cardiomyopathy and normal activation, and 23 with dilated cardiomyopathy and LBBB. An additional 30 patients (nine with normal ventricular systolic function and 21 with dilated cardiomyopathy) were studied before and after right ventricular pacing. Left ventricular ejection and filling times were measured by pulsed wave Doppler and cavity size by M mode echocardiography.
RESULTS—Z ratio was independent of RR interval in all groups. Mean (SD) Z ratio was 82 (10)% for normal subjects, 66 (10)% for isolated LBBB (p < 0.01 v normal), 77 (7)% for dilated cardiomyopathy without LBBB (NS v normal), and 61 (7)% for dilated cardiomyopathy with LBBB (p < 0.01 v normal). In the nine patients with normal left ventricular size and QRS duration, Z ratio fell from 88 (6)% in sinus rhythm to 77 (10)% with right ventricular pacing (p = 0.26). In the 21 patients with dilated cardiomyopathy and LBBB, Z ratio rose from 59 (10)% in sinus rhythm to 74 (9)% with right ventricular DDD pacing (p < 0.001).
CONCLUSIONS—Z ratio dissociates the effects of abnormal ventricular activation and systolic disease. It also clearly differentiates right ventricular pacing from LBBB. It may thus be useful in comparing the haemodynamic effects of different pacing modes in patients with or without left ventricular disease.


Keywords: dilated cardiomyopathy; pacemaker; left bundle branch block; echocardiography. PMID:10956289

  17. Echocardiographic Predictors of Ventricular Tachycardia

    PubMed Central

    Catanzaro, John N; Makaryus, John N; Makaryus, Amgad N; Sison, Cristina; Vavasis, Christos; Fan, Dali; Jadonath, Ram

    2014-01-01

    BACKGROUND Patients with structural heart disease are prone to ventricular tachycardia (VT) and ventricular fibrillation (VF), which account for the majority of sudden cardiac deaths (SCDs). We sought to examine echocardiographic parameters that can predict VT as documented by implantable cardioverter-defibrillator (ICD) appropriate discharge. We examine echocardiographic parameters other than ejection fraction that may predict VT as recorded via rates of ICD discharge. METHODS Analysis of 586 patients (469 males; mean age = 68 ± 3 years; mean follow-up time of 11 ± 14 months) was undertaken. Echo parameters assessed included left ventricular (LV) internal end diastolic/systolic dimension (LVIDd, LVIDs), relative wall thickness (RWT), and left atrial (LA) size. RESULTS The incidence of VT was 0.22 (114 VT episodes per 528 person-years of follow-up time). Median time-to-first VT was 3.8 years. VT was documented in 79 patients (59 first VT incidence, 20 multiple). The echocardiographic parameter associated with first VT was LVIDs >4 cm (P = 0.02). CONCLUSION The main echocardiographic predictor associated with the first occurrence of VT was LVIDs >4 cm. Patients with an LVIDs >4 cm were 2.5 times more likely to have an episode of VT. Changes in these echocardiographic parameters may warrant aggressive pharmacologic therapy and implantation of an ICD. PMID:25861227

  18. Regional myocardial shape and dimensions of the working isolated canine left ventricle

    NASA Technical Reports Server (NTRS)

    Ritman, E. L.; Tsuiki, K.; Donald, D.; Wood, E. H.

    1975-01-01

    The extent to which the dynamic shape and dimensions of the isolated left ventricular myocardial wall differ throughout the myocardium and how these differences are characteristic of the anatomic location was demonstrated. The use of a biplane X-ray technique and a metabolically-supported isolated canine left ventricle preparation provided an angiographically ideal means of measuring mechanical dynamics of the myocardium while the intact left ventricular myocardial structure and electrical activation pattern retains most of the in situ ventricular characteristics.

  19. Left ventricular pseudoaneurysm after reimplantation procedure.

    PubMed

    Inoue, Takahiro; Hashimoto, Kazuhiro; Sakamoto, Yoshimasa; Yoshitake, Michio; Matsumura, Yoko; Kinami, Hiroo; Takagi, Tomomitsu

    2016-04-01

    Postoperative left ventricular pseudoaneurysm is a rare, but potentially lethal, complication because of the high risk of rupture and high mortality of repair. We report a 64-year-old man with Marfan syndrome who underwent the reimplantation valve-sparing aortic root replacement complicated by a postoperative left ventricular pseudoaneurysm that required urgent repair. Careful handling of the aortic root is required to avoid a left ventricular pseudoaneurysm, particularly in patients with connective tissue disorder. PMID:24917204

  20. Hypokalemia-induced ultrastructural, histochemical and connexin-43 alterations resulting in atrial and ventricular fibrillations.

    PubMed

    Tribulová, N; Manoach, M; Varon, D; Okruhlicová, L; Slobodová, Z; Kubovcáková, L

    1999-12-01

    Perfusion of the isolated guinea pig heart with hypokalemic solution provide simple model for examination of the molecular mechanisms involved in the incidence of atrial and/or ventricular fibrillations. The results point out that dispersion of the metabolic and subcellular alterations and heterogenously impaired intercellular coupling might account for electrical disturbances and desynchronization of the myocardium thus facilitate occurrence of fibrillation. PMID:10707826

  1. Right ventricular failure after left ventricular assist devices.

    PubMed

    Lampert, Brent C; Teuteberg, Jeffrey J

    2015-09-01

    Most patients with advanced systolic dysfunction who are assessed for a left ventricular assist device (LVAD) also have some degree of right ventricular (RV) dysfunction. Hence, RV failure (RVF) remains a common complication of LVAD placement. Severe RVF after LVAD implantation is associated with increased peri-operative mortality and length of stay and can lead to coagulopathy, altered drug metabolism, worsening nutritional status, diuretic resistance, and poor quality of life. However, current medical and surgical treatment options for RVF are limited and often result in significant impairments in quality of life. There has been continuing interest in developing risk models for RVF before LVAD implantation. This report reviews the anatomy and physiology of the RV and how it changes in the setting of LVAD support. We will discuss proposed mechanisms and describe biochemical, echocardiographic, and hemodynamic predictors of RVF in LVAD patients. We will describe management strategies for reducing and managing RVF. Finally, we will discuss the increasingly recognized and difficult to manage entity of chronic RVF after LVAD placement and describe opportunities for future research. PMID:26267741

  2. Idiopathic left ventricular apical hypoplasia.

    PubMed

    Raza, Ali; Waleed, Mohammad; Balerdi, Matthew; Bragadeesh, Thanjavur; Clark, Andrew L

    2014-01-01

    A 46-year-old man was found to have an abnormal ECG taken during a routine health and blood pressure check. His only symptom was non-specific central chest discomfort, unrelated to exertion. His ECG showed sinus rhythm, a normal axis and poor R wave progression across the chest leads and lateral T wave flattening. An echocardiogram showed a dilated left ventricle with a thin and hypokinetic septum bulging to the right. The apex was 'not well seen' but also appeared thin and hypokinetic. The right heart and valves were normal. The patient was further investigated for left ventricular hypoplasia. PMID:24585345

  3. Epicardial Ablation For Ventricular Tachycardia

    PubMed Central

    Maccabelli, Giuseppe; Mizuno, Hiroya; Della Bella, Paolo

    2012-01-01

    Epicardial ablation has lately become a necessary tool to approach some ventricular tachycardias in different types of cardiomyopathy. Its diffusion is now limited to a few high volume centers not because of the difficulty of the pericardial puncture but since it requires high competence not only in the VT ablation field but also in knowing and recognizing the possible complications each of which require a careful treatment. This article will review the state of the art of epicardial ablation with special attention to the procedural aspects and to the possible selection criteria of the patients PMID:23233758

  4. 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

  5. Outflow Tract Premature Ventricular Contractions and Ventricular Tachycardia: The Typical and the Challenging.

    PubMed

    John, Roy M; Stevenson, William G

    2016-09-01

    The ventricular outflow tracts are the most common sites of origin for ventricular arrhythmias that occur in the absence of structural heart disease. Drug therapy with β-blockers and calcium blockers has limited efficacy for control. In the presence of marked symptoms or frequent arrhythmia causing left ventricular (LV) dysfunction, catheter ablation is a consideration. The right ventricular outflow tract, aortic root, LV outflow endocardium, and epicardium are potential sites for ablation for these arrhythmias. In intractable cases of highly symptomatic ventricular arrhythmias originating from the LV summit, surgical ablation is an option. PMID:27521088

  6. FGF23 induces left ventricular hypertrophy

    PubMed Central

    Faul, Christian; Amaral, Ansel P.; Oskouei, Behzad; Hu, Ming-Chang; Sloan, Alexis; Isakova, Tamara; Gutiérrez, Orlando M.; Aguillon-Prada, Robier; Lincoln, Joy; Hare, Joshua M.; Mundel, Peter; Morales, Azorides; Scialla, Julia; Fischer, Michael; Soliman, Elsayed Z.; Chen, Jing; Go, Alan S.; Rosas, Sylvia E.; Nessel, Lisa; Townsend, Raymond R.; Feldman, Harold I.; St. John Sutton, Martin; Ojo, Akinlolu; Gadegbeku, Crystal; Di Marco, Giovana Seno; Reuter, Stefan; Kentrup, Dominik; Tiemann, Klaus; Brand, Marcus; Hill, Joseph A.; Moe, Orson W.; Kuro-o, Makoto; Kusek, John W.; Keane, Martin G.; Wolf, Myles

    2011-01-01

    Chronic kidney disease (CKD) is a public health epidemic that increases risk of death due to cardiovascular disease. Left ventricular hypertrophy (LVH) is an important mechanism of cardiovascular disease in individuals with CKD. Elevated levels of FGF23 have been linked to greater risks of LVH and mortality in patients with CKD, but whether these risks represent causal effects of FGF23 is unknown. Here, we report that elevated FGF23 levels are independently associated with LVH in a large, racially diverse CKD cohort. FGF23 caused pathological hypertrophy of isolated rat cardiomyocytes via FGF receptor–dependent activation of the calcineurin-NFAT signaling pathway, but this effect was independent of klotho, the coreceptor for FGF23 in the kidney and parathyroid glands. Intramyocardial or intravenous injection of FGF23 in wild-type mice resulted in LVH, and klotho-deficient mice demonstrated elevated FGF23 levels and LVH. In an established animal model of CKD, treatment with an FGF–receptor blocker attenuated LVH, although no change in blood pressure was observed. These results unveil a klotho-independent, causal role for FGF23 in the pathogenesis of LVH and suggest that chronically elevated FGF23 levels contribute directly to high rates of LVH and mortality in individuals with CKD. PMID:21985788

  7. Ventricular-Fold Dynamics in Human Phonation

    ERIC Educational Resources Information Center

    Bailly, Lucie; Bernardoni, Nathalie Henrich; Müller, Frank; Rohlfs, Anna-Katharina; Hess, Markus

    2014-01-01

    Purpose: In this study, the authors aimed (a) to provide a classification of the ventricular-fold dynamics during voicing, (b) to study the aerodynamic impact of these motions on vocal-fold vibrations, and (c) to assess whether ventricular-fold oscillations could be sustained by aerodynamic coupling with the vocal folds. Method: A 72-sample…

  8. An Unusual Etiology for Bidirectional Ventricular Tachycardia.

    PubMed

    Zhao, Yun-Tao; Wang, Lei; Yi, Zhong

    2016-03-01

    Bidirectional ventricular tachycardia is a rare variety of tachycardia with a morphologically distinct presentation. The QRS axis and/or morphology alternate in the frontal plane leads. We report a patient with bidirectional ventricular tachycardia in association with aconitine poisoning. PMID:26604120

  9. Bidirectional ventricular tachycardia of unusual etiology

    PubMed Central

    Chakraborty, Praloy; Kaul, Bhavna; Mandal, Kausik; Isser, H.S.; Bansal, Sandeep; Subramanian, Anandaraja

    2016-01-01

    Bidirectional ventricular tachycardia (BDVT) is a rare form of ventricular arrhythmia, characterized by changing QRS axis of 180 degrees. Digitalis toxicity is considered as commonest cause of BDVT; other causes include aconite toxicity, myocarditis, myocardial infarction, metastatic cardiac tumour and cardiac channelopathies. We describe a case of BDVT in a patient with Anderson-Tawil syndrome.

  10. 21 CFR 882.4060 - Ventricular cannula.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ventricular cannula. 882.4060 Section 882.4060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  11. 21 CFR 882.4060 - Ventricular cannula.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ventricular cannula. 882.4060 Section 882.4060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  12. 21 CFR 882.4060 - Ventricular cannula.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ventricular cannula. 882.4060 Section 882.4060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  13. 21 CFR 882.4060 - Ventricular cannula.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular cannula. 882.4060 Section 882.4060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  14. 21 CFR 882.4060 - Ventricular cannula.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ventricular cannula. 882.4060 Section 882.4060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular cannula is a device used to puncture the ventricles of the brain for aspiration...

  15. What Is a Ventricular Assist Device?

    MedlinePlus

    ... basic types of VADs are a left ventricular assist device (LVAD) and a right ventricular assist device (RVAD). If both types are used at the same time, they're called a biventricular assist device (BIVAD). The LVAD is the most common type of VAD. It ...

  16. Right Ventricular Dysfunction in Chronic Lung Disease

    PubMed Central

    Kolb, Todd M.; Hassoun, Paul M.

    2012-01-01

    Right ventricular dysfunction arises in chronic lung disease when chronic hypoxemia and disruption of pulmonary vascular beds contribute to increase ventricular afterload, and is generally defined by hypertrophy with preserved myocardial contractility and cardiac output. Although the exact prevalence is unknown, right ventricular hypertrophy appears to be a common complication of chronic lung disease, and more frequently complicates advanced lung disease. Right ventricular failure is rare, except during acute exacerbations of chronic lung disease or when multiple co-morbidities are present. Treatment is targeted at correcting hypoxia and improving pulmonary gas exchange and mechanics. There are presently no convincing data to support the use of pulmonary hypertension-specific therapies in patients with right ventricular dysfunction secondary to chronic lung disease. PMID:22548815

  17. Takotsubo cardiomyopathy recurrence with left ventricular apical ballooning following isolated right ventricular involvement: A case report

    PubMed Central

    JOE, BYUNG-HYUN; HWANG, HUI-JEONG; PARK, CHANG-BUM; JIN, EUN-SUN; SOHN, IL-SUK; CHO, JIN-MAN; KIM, CHONG-JIN

    2013-01-01

    We report a case of Takotsubo cardiomyopathy, which involved the right ventricle at first presentation and demonstrated involvement of the left ventricle during recurrence. The patient was admitted to Kyung Hee University Hospital due to a left hip fracture, which was considered a result of physical stress. Complete recovery was confirmed by echocardiography prior to recurrence. The cause of the second event was surgery for the left hip fracture. Recurrence of Takotsubo cardiomyopathy at various cardiac locations provides evidence against the existing hypotheses that variants of Takotsubo cardiomyopathy are associated with anatomically different distributions of cardiac adrenergic receptors, the degree of stimulation by sympathetic activity and different susceptibilities to such sympathetic stimulation. PMID:23935757

  18. Coronary haemodynamics in left ventricular hypertrophy.

    PubMed Central

    Wallbridge, D. R.; Cobbe, S. M.

    1996-01-01

    BACKGROUND: Left ventricular hypertrophy is associated with an increased risk of cardiovascular morbidity and mortality. Previous studies have shown that patients with left ventricular hypertrophy develop electrocardiographic changes and left ventricular dysfunction during acute hypotension, and suggest that the lower end of autoregulation may be shifted upwards. AIM: To measure coronary blood flow (velocity) and flow reserve during acute hypotension in patients with left ventricular hypertrophy. PATIENTS: Eight patients with atypical chest pain and seven with hypertensive left ventricular hypertrophy; all with angiographically normal epicardial vessels. SETTING: Tertiary referral centre. METHODS: The physiological range of blood pressure was determined by previous ambulatory monitoring. Left ventricular mass was determined by echocardiography. At cardiac catheterisation, left coronary blood flow velocity was measured using a Judkins style Doppler tipped catheter. During acute hypotension with sodium nitroprusside, coronary blood flow velocity was recorded at rest and during maximal hyperaemia induced by intracoronary injection of adenosine. Quantitative coronary angiography was performed manually. RESULTS: For both groups coronary blood flow velocity remained relatively constant over a range of physiological diastolic blood pressures and showed a steep relation with diastolic blood pressure during maximal hyperaemia with intracoronary adenosine. Absolute coronary blood flow (calculated from quantitative angiographic data), standardised for left ventricular mass, showed reduced flow in the hypertensive group at rest and during maximal vasodilatation. CONCLUSION: The results are consistent with an inadequate blood supply to the hypertrophied heart, but no upward shift of the lower end of the autoregulatory range was observed. PMID:8705764

  19. Ventricular Aneurysm Following Myocardial Infarction

    PubMed Central

    Walters, M. B.

    1966-01-01

    Cineradiographic examination appears to be the best method for the study of cardiac pulsations. Fifty consecutive patients, who had sustained transmural myocardial infarction at least six months previously, were studied by this technique. Thirty-six had some abnormality of pulsation and eight had dynamic ventricular aneurysm. Six of the eight had suffered severe infarct. Functional recovery in those with aneurysm was not as complete as in the rest of the group. Two made a poor functional recovery, two a fair recovery, and four a moderately good recovery. Clinically, there were no systemic emboli in the patients with dynamic aneurysms. Five of the 50 had persistent ST-segment elevation and “coving” of the T waves; three of these patients had aneurysms. There was no good correlation between the electrocardiographic site of the infarct and the site of the abnormal pulsation. ImagesFig. 1 PMID:5928534

  20. Ventricular capture by anodal pacemaker stimulation.

    PubMed

    Occhetta, Eraldo; Bortnik, Miriam; Marino, Paolo

    2006-05-01

    This report describes the case of an 86-year-old male with syncopal paroxysmal 2:1 atrioventricular block and a single chamber VVI pacemaker programmed to bipolar sensing and unipolar pacing. After recurrence of syncope, a complete loss of ventricular capture with regular ventricular sensing was observed on ECG; fluoroscopic examination suggested perforation of the right ventricle by the helix of the implanted screw-in lead. Reprogramming the pacemaker to bipolar pacing/sensing resulted in regular ventricular capture and sensing, suggesting effective anodal stimulation from the ring electrode permitting complete non-invasive palliation. PMID:16636000

  1. Ventricular-Vascular Interaction in Heart Failure

    PubMed Central

    Borlaug, Barry A.; Kass, David A.

    2008-01-01

    Synopsis Nearly half of all patients with heart failure have preserved ejection fraction (HFpEF). HFpEF patients tend to be older, female, and hypertensive, and characteristically display increased ventricular and arterial stiffening. In this review, we discuss the pathophysiology of abnormal ventriculoarterial stiffening and how the latter affects ventricular function, cardiovascular hemodynamics, reserve capacity, and symptoms. We conclude by exploring how novel treatment strategies targeting abnormal ventricular-arterial interaction might prove useful in the treatment of patients with HFpEF. PMID:18313622

  2. Memory and ventricular size in alcoholics.

    PubMed

    Acker, C; Jacobson, R R; Lishman, W A

    1987-05-01

    The relationship between memory performance and CT scan measures of ventricular size was investigated in a sample of 39 chronic alcoholics and 39 controls. Measures of verbal, non-verbal, recognition and recall memory were derived from the tests administered and were viewed in relation to the lateral ventricle and third ventricular size measurements. The results showed that the memory performance of male alcoholics was significantly related to measures of third ventricular size, but probably not to measures of the lateral ventricles. An association between verbal memory performance and CT scan measures was found in the male controls. PMID:3602226

  3. Intravenous disopyramide phosphate and ventricular overdrive pacing in the termination of paroxysmal ventricular tachycardia.

    PubMed

    Camm, J; Ward, D; Washington, H G; Spurrell, R A

    1979-07-01

    Both antiarrhythmic drugs and bursts of rapid ventricular pacing provide alternatives to DC cardioversion for the treatment of paroxysmal ventricular tachycardia. This report considers the individual and combined success of burst ventricular pacing and intravenous disopyramide phosphate in the tretment of 11 examples of paroxysmal ventricular tachycardia. Rapid ventricular pacing, at a rate of up to 50 beats/min faster than the tachycardia rate terminated 7 of the tachycardias. Intravenous disopyramide resulted in increased tachycardiac cycle length (342 +/- 34 ms-385 +/- 56 ms), increased QRS complex width (147 +/- 42 ms-180 +/- 41 ms) and termination of 8 the tachycardias. The remaining 3 tachycardias could be terminated by bursts of ventricular pacing following the infusion of disopyramide. Of these, 2 could not be terminated prior to disopyramide. The use of both techniques allowed the extinction of all 11 tachycardias and prevented the need to proceed to DC conversion. PMID:95308

  4. Discrete series of unitary irreducible representations of the U{sub q}(u(3, 1)) and U{sub q}(u(n, 1)) noncompact quantum algebras

    SciTech Connect

    Smirnov, Yu. F.; Asherova, R. M.

    2011-06-15

    The structure of all discrete series of unitary irreducible representations of the U{sub q}(u(3, 1)) and U{sub q}(u(n, 1)) noncompact quantum algebras are investigated with the aid of extremal projection operators and the q-analog of the Mickelsson-Zhelobenko algebra Z(g, g Prime ){sub q}. The orthonormal basis constructed in the infinite-dimensional space of irreducible representations of the U{sub q}(u(n, 1)) Superset-Of-Or-Equal-To U{sub q}(u(n)) algebra is the q-analog of the Gelfand-Graev basis in the space of the corresponding irreducible representations of the u(n, 1) Superset-Of-Or-Equal-To u(n) classical algebra.

  5. Arrhythmogenic ventricular cardiomyopathy: A paradigm shift from right to biventricular disease

    PubMed Central

    Saguner, Ardan M; Brunckhorst, Corinna; Duru, Firat

    2014-01-01

    Arrhythmogenic ventricular cardiomyopathy (AVC) is generally referred to as arrhythmogenic right ventricular (RV) cardiomyopathy/dysplasia and constitutes an inherited cardiomyopathy. Affected patients may succumb to sudden cardiac death (SCD), ventricular tachyarrhythmias (VTA) and heart failure. Genetic studies have identified causative mutations in genes encoding proteins of the intercalated disk that lead to reduced myocardial electro-mechanical stability. The term arrhythmogenic RV cardiomyopathy is somewhat misleading as biventricular involvement or isolated left ventricular (LV) involvement may be present and thus a broader term such as AVC should be preferred. The diagnosis is established on a point score basis according to the revised 2010 task force criteria utilizing imaging modalities, demonstrating fibrous replacement through biopsy, electrocardiographic abnormalities, ventricular arrhythmias and a positive family history including identification of genetic mutations. Although several risk factors for SCD such as previous cardiac arrest, syncope, documented VTA, severe RV/LV dysfunction and young age at manifestation have been identified, risk stratification still needs improvement, especially in asymptomatic family members. Particularly, the role of genetic testing and environmental factors has to be further elucidated. Therapeutic interventions include restriction from physical exercise, beta-blockers, sotalol, amiodarone, implantable cardioverter-defibrillators and catheter ablation. Life-long follow-up is warranted in symptomatic patients, but also asymptomatic carriers of pathogenic mutations. PMID:24772256

  6. Polymorphic Ventricular Tachycardia/Ventricular Fibrillation and Sudden Cardiac Death in the Normal Heart.

    PubMed

    Shah, Ashok J; Hocini, Meleze; Denis, Arnaud; Derval, Nicolas; Sacher, Frederic; Jais, Pierre; Haissaguerre, Michel

    2016-09-01

    Primary electrical diseases manifest with polymorphic ventricular tachycardia (PMVT) and ventricular fibrillation (VF) and along with idiopathic VF contribute to about 10% of sudden cardiac deaths (SCDs) overall. These disorders include long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome, and early repolarization syndrome. This article reviews the clinical electrophysiological management of PMVT/VF in a structurally normal heart affected with these disorders. PMID:27521091

  7. Chiral symmetry breaking in monolayer graphene by strong coupling expansion of compact and non-compact U(1) lattice gauge theories

    SciTech Connect

    Araki, Yasufumi

    2011-06-15

    Research Highlights: > Monolayer graphene is treated by strong coupling expansion of lattice gauge theory. > Spontaneous gap generation is shown in the strong coupling regime. > Results from compact and non-compact gauge formulations are compared. > Dispersion relation of the collective excitations are derived. - Abstract: Due to effective enhancement of the Coulomb coupling strength in the vacuum-suspended graphene, the system may turn from a semimetal into an insulator by the formation of a gap in the fermionic spectrum. This phenomenon is analogous to the spontaneous breaking of chiral symmetry in the strong-coupling relativistic field theories. We study this 'chiral symmetry breaking' and associated collective excitations on graphene in the strong coupling regime by taking U(1) lattice gauge theory as an effective model for graphene. Both compact and non-compact formulations of the U(1) gauge action show chiral symmetry breaking with equal magnitude of the chiral condensate (exciton condensate) in the strong coupling limit, while they start to deviate from the next-to-leading order in the strong coupling expansion. Phase and amplitude fluctuations of the order parameter are also investigated: in particular, a mass formula for the pseudo-Nambu-Goldstone mode ({pi}-exciton), which is analogous to Gell-Mann-Oakes-Renner relation for the pion in quantum chromodynamics (QCD), is derived from the axial Ward-Takahashi identity. To check the applicability of the effective field theory description, typical energy scales of fermionic and bosonic excitations are estimated by identifying the lattice spacing of the U(1) gauge theory with that of the original honeycomb lattice of graphene.

  8. Left ventricular function in patients with ventricular arrhythmias and aortic valve disease

    SciTech Connect

    Santinga, J.T.; Kirsh, M.M.; Brady, T.J.; Thrall, J.; Pitt, B.

    1983-02-01

    Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease.

  9. Rest and exercise ventricular function in adults with congenital ventricular septal defects

    SciTech Connect

    Jablonsky, G.; Hilton, J.D.; Liu, P.P.; Morch, J.E.; Druck, M.N.; Bar-Shlomo, B.Z.; McLaughlin, P.R.

    1983-01-15

    Rest and exercise right and left ventricular function were compared using equilibrium gated radionuclide angiography in 19 normal sedentary control subjects and 34 patients with hemodynamically documented congenital ventricular septal defect (VSD). Gated radionuclide angiography was performed at rest and during each level of graded supine bicycle exercise to fatigue. Heart rate, blood pressure, maximal work load achieved, and right and left ventricular ejection fractions were assessed. The control subjects demonstrated an increase in both the left and right ventricular ejection fractions with exercise. All study groups failed to demonstrate an increase in ejection fraction in either ventricle with exercise. Furthermore, resting left ventricular ejection fraction in Groups 2 and 3 was lower than that in the control subjects and resting right ventricular ejection fraction was lower in Group 3 versus control subjects. Thus left and right ventricular function on exercise were abnormal in patients with residual VSD as compared with control subjects; rest and exercise left ventricular ejection fractions remained abnormal despite surgical closure of VSD in the remote past; resting left and right ventricular function was abnormal in patients with Eisenmenger's complex; lifelong volume overload may be detrimental to myocardial function.

  10. [Ventricular Septal Perforation after Inferior Myocardial Infarction].

    PubMed

    Sato, Hisashi; Nakayama, Yoshihiro; Tanaka, Hideya; Takahashi, Baku

    2016-07-01

    We report a rare case of ventricular septal perforation (VSP) after inferior myocardial infarction. Surgical repair of VSP after inferior infarction is technically difficult because of its anatomical location. An 81-year-old female presented with dyspnea on the 8th day after percutaneous coronary intervention for acute inferior myocardial infarction. Echocardiography revealed a ventricular septal perforation. Urgent operation was performed. There was a VSP around the base of the ventricular septum. The myocardial infarction extended to the adjacent muscle of the mitral valve annulus. Two bovine pericardial patches were used in the left ventricular cavity. The patches were sewn on the mitral valve annulus which was the only normal tissue in the region. The 1st patch was used to close the VSP directly, and the 2nd patch was sutured to the normal myocardium to exclude the infracted area. No residual shunt flow was observed. The postoperative course was uneventful. PMID:27365060

  11. Ventricular repolarization measures for arrhythmic risk stratification

    PubMed Central

    Monitillo, Francesco; Leone, Marta; Rizzo, Caterina; Passantino, Andrea; Iacoviello, Massimo

    2016-01-01

    Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave (QT). Several physiological, pathological and iatrogenic factors can influence ventricular repolarization. It has been demonstrated that small perturbations in this process can be a potential trigger of malignant arrhythmias, therefore the analysis of ventricular repolarization represents an interesting tool to implement risk stratification of arrhythmic events in different clinical settings. The aim of this review is to critically revise the traditional methods of static analysis of ventricular repolarization as well as those for dynamic evaluation, their prognostic significance and the possible application in daily clinical practice. PMID:26839657

  12. Sequential Notch activation regulates ventricular chamber development

    PubMed Central

    D'Amato, Gaetano; Luxán, Guillermo; del Monte-Nieto, Gonzalo; Martínez-Poveda, Beatriz; Torroja, Carlos; Walter, Wencke; Bochter, Matthew S.; Benedito, Rui; Cole, Susan; Martinez, Fernando; Hadjantonakis, Anna-Katerina; Uemura, Akiyoshi; Jiménez-Borreguero, Luis J.; de la Pompa, José Luis

    2016-01-01

    Ventricular chambers are essential for the rhythmic contraction and relaxation occurring in every heartbeat throughout life. Congenital abnormalities in ventricular chamber formation cause severe human heart defects. How the early trabecular meshwork of myocardial fibres forms and subsequently develops into mature chambers is poorly understood. We show that Notch signalling first connects chamber endocardium and myocardium to sustain trabeculation, and later coordinates ventricular patterning and compaction with coronary vessel development to generate the mature chamber, through a temporal sequence of ligand signalling determined by the glycosyltransferase manic fringe (MFng). Early endocardial expression of MFng promotes Dll4–Notch1 signalling, which induces trabeculation in the developing ventricle. Ventricular maturation and compaction require MFng and Dll4 downregulation in the endocardium, which allows myocardial Jag1 and Jag2 signalling to Notch1 in this tissue. Perturbation of this signalling equilibrium severely disrupts heart chamber formation. Our results open a new research avenue into the pathogenesis of cardiomyopathies. PMID:26641715

  13. Ventricular Septal Defect from Takotsubo Syndrome

    PubMed Central

    Caplow, Julie; Quatromoni, Neha

    2016-01-01

    Takotsubo Syndrome is a transient condition characterized by left ventricular systolic dysfunction with apical akinesis/dyskinesis and ballooning. Although the prognosis with medical management is excellent in most cases, rare cases of serious complications can occur. We present here a case of a 71-year-old woman presenting with acute decompensated heart failure with initial findings consistent with a myocardial infarction, who was found instead to have an acute ventricular septal defect as a complication of Takotsubo Syndrome. PMID:27563471

  14. [Ventricular contractility: Physiology and clinical projection].

    PubMed

    Domenech, Raúl J; Parra, Víctor M

    2016-06-01

    The contractile state of the heart is the result of myocardial contractility, the intrinsic mechanism that regulates the force and the shortening of the ventricle and determines the ventricular ejection volume. However, the ejection volume is also modulated by ventricular preload (diastolic ventricular volume) and afterload (resistance to ejection). Accordingly, a decrease in contractility may be masked by changes in preload or afterload, maintaining a normal ejection volume and delaying the diagnosis of myocardial damage. Thus, it is necessary to develop a non-invasive method to measure contractility in the clinical practice. We review in this article the basic principles of cardiac contraction, the concept of contractility and its measurement with the ventricular pressure-volume loop, an experimental method that also measures most of the hemodynamic variables of the cardiac cycle including preload, afterload, ventricular work, ventricular lusitropy and arterial elastance. This method has been recently validated in cardiac patients and allows to evaluate the evolution of contractility in heart failure in a non invasive way. Although some modifications are still necessary, it will probably have an extensive use in practical cardiology in the near future. PMID:27598497

  15. Resveratrol reduces intracellular free calcium concentration in rat ventricular myocytes.

    PubMed

    Liu, Zheng; Zhang, Li-Ping; Ma, Hui-Jie; Wang, Chuan; Li, Ming; Wang, Qing-Shan

    2005-10-25

    Resveratrol (trans-3, 4', 5-trihydroxy stilbene), a phytoalexin found in grape skins and red wine, has been reported to have a wide range of biological and pharmacological properties. It has been speculated that resveratrol may have cardioprotective activity. The objective of our study was to investigate the effects of resveratrol on intracellular calcium concentration ([Ca(2+)](i)) in rat ventricular myocytes. [Ca(2+)](i) was detected by laser scanning confocal microscopy. The results showed that resveratrol (15~60 mumol/L) reduced [Ca(2+)](i) in normal and Ca(2+)-free Tyrode's solution in a concentration-dependent manner. The effects of resveratrol on [Ca(2+)](i) in normal Tyrode's solution was partially inhibited by pretreatment with sodium orthovanadate (Na3VO4, 1.0 mmol/L, P<0.01), an inhibitor of protein tyrosine phosphatase, or L-type Ca(2+) channel agonist Bay K8644 (10 mumol/L, P<0.05), but could not be antagonized by NO synthase inhibitor L-NAME (1.0 mmol/L). Resveratrol also markedly inhibited the ryanodine-induced [Ca(2+)](i) increase in Ca(2+)-free Tyrode's solution (P<0.01). When Ca(2+) waves were produced by increasing extracellular Ca(2+) concentration from 1 to 10 mmol/L, resveratrol (60 mumol/L) could reduce the velocity and duration of propagating waves, and block the propagating waves of elevated [Ca(2+)](i). These results suggest that resveratrol may reduce the [Ca(2+)](i) in isolated rat ventricular myocytes. The inhibition of voltage-dependent Ca(2+) channel and tyrosine kinase, and alleviation of Ca(2+) release from sarcoplasmic reticulum (SR) are possibly involved in the effects of resveratrol on rat ventricular myocytes. These findings could help explain the protective activity of resveratrol against cardiovascular disease. PMID:16220198

  16. Anaesthesia and right ventricular failure.

    PubMed

    Forrest, P

    2009-05-01

    Acute right ventricular (RV) failure has until recently received relatively little attention in the cardiology, critical care or anaesthesia literature. However, it is frequently encountered in cardiac surgical cases and is a significant cause of mortality in patients with severe pulmonary hypertension who undergo non-cardiac surgery. RV dysfunction may be primarily due to impaired RV contractility, or volume or pressure overload. In these patients, an increased pulmonary vascular resistance (PVR) or a decreased aortic root pressure may lead to RV ischaemia, resulting in a rapid, downward haemodynamic spiral. The key aspects of 'RV protection' in patients who are at risk of perioperative decompensation are prevention, detection and treatment aimed at reversing the underlying pathophysiology. Minimising PVR and maintaining systemic blood pressure are of central importance in the prevention of RV decompensation, which is characterised by a rising central venous pressure and a falling cardiac output. Although there are no outcome data to support any therapeutic strategy for RV failure when PVR is elevated, the combination of inhaled iloprost or intravenous milrinone with oral sildenafil produces a synergistic reduction in PVR, while sparing systemic vascular resistance. Levosimendan is a promising new inotrope for the treatment of RV failure, although its role in comparison to older agents such as dobutamine, adrenaline and milrinone has yet to be determined. This is also the case for the use of vasopressin as an alternative pressor to noradrenaline. If all else has failed, mechanical support of the RV should be considered in selected cases. PMID:19499856

  17. Electrohydraulic ventricular assist device development.

    PubMed

    Diegel, P D; Mussivand, T; Holfert, J W; Juretich, J T; Miller, J A; Maclean, G K; Szurmak, Z; Santerre, J P; Rajagopalan, K; Dew, P A

    1992-01-01

    An electrohydraulic ventricular assist device has been developed. An axial flow pump driven by a brushless DC motor provides actuation. Energy is supplied by internal Ni/Cd batteries and by external Ag/Zn batteries, both rechargeable. Electromagnetic induction is used to pass energy through the skin with a transcutaneous energy transfer (TET) system. Physiologic control, battery management, motor commutation, and communication functions are performed by a surface mount internal controller. An infrared data link within the TET coils provides bidirectional communication between the external and internal controllers. A computer model was developed to predict system performance. The dimensions are 180 mm x 116 mm x 40 mm. An in vitro system pumped 5.7 L/min at 10 mmHg inflow and 100 mmHg outflow pressure. The internal battery can provide the projected energy requirements for 40 min after 540 charge/discharge cycles, and the external battery is capable of 4 hr of operation after 150 cycles. The TET system can deliver 60 W of power and exceeds 80% efficiency between 15 and 30 W. The device configuration is based on human cadaver and intraoperative fit trials. The device is being modified for calf implantation by redirecting the blood ports, increasing the output, and incorporating the internal controller in the unified device base. PMID:1457871

  18. Synchronized defibrillation for ventricular fibrillation

    PubMed Central

    Manoharan, Ganesh; Navarro, Cesar; Walsh, Simon J; Allen, John D; Anderson, John McC; Adgey, AA Jennifer

    2012-01-01

    Objective: Optimization of defibrillation success is important to improve efficacy and minimize post-shock sequelae. Previous work has suggested an improvement in shock success when an intracardiac shock is delivered synchronized to the upslope of a VF wave. We investigated the efficacy of transthoracic defibrillation success using a novel external biphasic defibrillator which delivers shocks synchronized to the upslope of the surface ECG. Methods: A prospective, controlled, randomized study in a research institute laboratory of male and female pigs (54.2±1.8 kg). Ventricular fibrillation (VF) was induced in 10 anaesthetized and ventilated pigs. Shocks were delivered randomly from a biphasic defibrillator in synchronized or non-synchronized mode via self-adhesive electrode pads following 30 s of VF. Energy settings at 50, 70, 80, and 100J were randomly tested. VF amplitude, impedance, and shock outcome were recorded and analysed digitally. Results: A total of 300 shocks were delivered. Synchronized shocks were delivered on the upslope of the VF wave in 99% of cases. There was no significant difference in shock success between shocks delivered in synchronized or non-synchronized modes (p=0.695). There was no significant difference in the amplitude of VF between successful and unsuccessful shocks (p=0.163). Furthermore, there was no association between shock success and transthoracic impedance. Conclusion: The novel defibrillator used in this study was able to consistently deliver shocks on the upslope portion of the VF wave but did not show an improvement in shock success. PMID:24062919

  19. Arrhythmogenic right ventricular cardiomyopathy/dysplasia.

    PubMed

    Thiene, Gaetano; Corrado, Domenico; Basso, Cristina

    2007-01-01

    Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a heart muscle disease clinically characterized by life-threatening ventricular arrhythmias. Its prevalence has been estimated to vary from 1:2,500 to 1:5,000. ARVC/D is a major cause of sudden death in the young and athletes. The pathology consists of a genetically determined dystrophy of the right ventricular myocardium with fibro-fatty replacement to such an extent that it leads to right ventricular aneurysms. The clinical picture may include: a subclinical phase without symptoms and with ventricular fibrillation being the first presentation; an electrical disorder with palpitations and syncope, due to tachyarrhythmias of right ventricular origin; right ventricular or biventricular pump failure, so severe as to require transplantation. The causative genes encode proteins of mechanical cell junctions (plakoglobin, plakophilin, desmoglein, desmocollin, desmoplakin) and account for intercalated disk remodeling. Familiar occurrence with an autosomal dominant pattern of inheritance and variable penetrance has been proven. Recessive variants associated with palmoplantar keratoderma and woolly hair have been also reported. Clinical diagnosis may be achieved by demonstrating functional and structural alterations of the right ventricle, depolarization and repolarization abnormalities, arrhythmias with the left bundle branch block morphology and fibro-fatty replacement through endomyocardial biopsy. Two dimensional echo, angiography and magnetic resonance are the imaging tools for visualizing structural-functional abnormalities. Electroanatomic mapping is able to detect areas of low voltage corresponding to myocardial atrophy with fibro-fatty replacement. The main differential diagnoses are idiopathic right ventricular outflow tract tachycardia, myocarditis, dialted cardiomyopathy and sarcoidosis. Only palliative therapy is available and consists of antiarrhythmic drugs, catheter ablation and

  20. Left ventricular function: time-varying elastance and left ventricular aortic coupling.

    PubMed

    Walley, Keith R

    2016-01-01

    Many aspects of left ventricular function are explained by considering ventricular pressure-volume characteristics. Contractility is best measured by the slope, Emax, of the end-systolic pressure-volume relationship. Ventricular systole is usefully characterized by a time-varying elastance (ΔP/ΔV). An extended area, the pressure-volume area, subtended by the ventricular pressure-volume loop (useful mechanical work) and the ESPVR (energy expended without mechanical work), is linearly related to myocardial oxygen consumption per beat. For energetically efficient systolic ejection ventricular elastance should be, and is, matched to aortic elastance. Without matching, the fraction of energy expended without mechanical work increases and energy is lost during ejection across the aortic valve. Ventricular function curves, derived from ventricular pressure-volume characteristics, interact with venous return curves to regulate cardiac output. Thus, consideration of ventricular pressure-volume relationships highlight features that allow the heart to efficiently respond to any demand for cardiac output and oxygen delivery. PMID:27613430

  1. Cardiac Metastasis of Leiomyosarcoma Complicated with Complete Atrio-Ventricular Block and Ventricular Tachycardia

    PubMed Central

    Shin, Jae Ouk; Kim, Minsu; Kang, Woong Chol; Moon, Jeonggeun; Chung, Wook-Jin; Sung, Yon Mi

    2016-01-01

    We described a case of a 54-year-old male who presented with dizziness and dyspnea due to cardiac metastasis of leiomyosarcoma. Cardiac metastasis of leiomyosarcoma caused both bradyarrhythmia and tachyarrhythmia in the patient. He was treated with implantation of a permanent pacemaker for management of complete atrio-ventricular block and anti-arrhythmic drug that suppressed ventricular tachycardia successfully. PMID:27014358

  2. Mitral subannular left ventricular aneurysm. A case presenting with ventricular tachycardia.

    PubMed Central

    Fitchett, D H; Kanji, M

    1983-01-01

    A young African immigrant presented with ventricular tachycardia in association with two mitral subannular left ventricular aneurysms. Although an unusual finding, the recognition of such aneurysms is important as prophylactic measures may prevent complications. Furthermore, they are a surgically treatable cause of heart failure and arrhythmias. Images PMID:6652004

  3. Significance of Late Gadolinium Enhancement at Right Ventricular Attachment to Ventricular Septum in Patients With Hypertrophic Cardiomyopathy.

    PubMed

    Chan, Raymond H; Maron, Barry J; Olivotto, Iacopo; Assenza, Gabriele E; Haas, Tammy S; Lesser, John R; Gruner, Christiane; Crean, Andrew M; Rakowski, Harry; Rowin, Ethan; Udelson, James; Lombardi, Massimo; Tomberli, Benedetta; Spirito, Paolo; Formisano, Francesco; Marra, Martina P; Biagini, Elena; Autore, Camillo; Manning, Warren J; Appelbaum, Evan; Roberts, William C; Basso, Cristina; Maron, Martin S

    2015-08-01

    Cardiovascular magnetic resonance (CMR) with extensive late gadolinium enhancement (LGE) is a novel marker for increased risk for sudden death (SD) in patients with hypertrophic cardiomyopathy (HC). Small focal areas of LGE confined to the region of right ventricular (RV) insertion to ventricular septum (VS) have emerged as a frequent and highly visible CMR imaging pattern of uncertain significance. The aim of this study was to evaluate the prognostic significance of LGE confined to the RV insertion area in patients with HC. CMR was performed in 1,293 consecutive patients with HC from 7 HC centers, followed for 3.4 ± 1.7 years. Of 1,293 patients (47 ± 14 years), 134 (10%) had LGE present only in the anterior and/or inferior areas of the RV insertion to VS, occupying 3.7 ± 2.9% of left ventricular myocardium. Neither the presence nor extent of LGE in these isolated areas was a predictor of adverse HC-related risk, including SD (adjusted hazard ratio 0.82, 95% confidence interval 0.45 to 1.50, p = 0.53; adjusted hazard ratio 1.16/10% increase in LGE, 95% confidence interval 0.29 to 4.65, p = 0.83, respectively). Histopathology in 20 HC hearts show the insertion areas of RV attachment to be composed of a greatly expanded extracellular space characterized predominantly by interstitial-type fibrosis and interspersed disorganized myocyte patterns and architecture. In conclusion, LGE confined to the insertion areas of RV to VS was associated with low risk of adverse events (including SD). Gadolinium pooling in this region of the left ventricle does not reflect myocyte death and repair with replacement fibrosis or scarring. PMID:26026863

  4. Exercise thallium testing in ventricular preexcitation

    SciTech Connect

    Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

    1987-05-01

    Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation.

  5. Distinguishing ventricular septal bulge versus hypertrophic cardiomyopathy in the elderly.

    PubMed

    Canepa, Marco; Pozios, Iraklis; Vianello, Pier Filippo; Ameri, Pietro; Brunelli, Claudio; Ferrucci, Luigi; Abraham, Theodore P

    2016-07-15

    The burgeoning evidence of patients diagnosed with sigmoidal hypertrophic cardiomyopathy (HCM) later in life has revived the quest for distinctive features that may help discriminate it from more benign forms of isolated septal hypertrophy often labelled ventricular septal bulge (VSB). HCM is diagnosed less frequently than VSB at older ages, with a reversed female predominance. Most patients diagnosed with HCM at older ages suffer from hypertension, similar to those with VSB. A positive family history of HCM and/or sudden cardiac death and the presence of exertional symptoms usually support HCM, though they are less likely in older patients with HCM, and poorly investigated in individuals with VSB. A more severe hypertrophy and the presence of left ventricular outflow obstruction are considered diagnostic of HCM, though stress echocardiography has not been consistently used in VSB. Mitral annulus calcification is very prevalent in both conditions, whereas a restrictive filling pattern is found in a minority of older patients with HCM. Genetic testing has low applicability in this differential diagnosis at the current time, given that a causative mutation is found in less than 10% of elderly patients with suspected HCM. Emerging imaging modalities that allow non-invasive detection of myocardial fibrosis and disarray may help, but have not been fully investigated. Nonetheless, there remains a considerable morphological overlap between the two conditions. Comprehensive studies, particularly imaging based, are warranted to offer a more evidence-based approach to elderly patients with focal septal thickening. PMID:27122487

  6. Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report.

    PubMed

    Yue-Chun, Li; Jia-Feng, Lin; Jia-Xuan, Lin

    2015-10-01

    Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes. PMID:26496347

  7. Left ventricular wall stress compendium.

    PubMed

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models

  8. Modified Stumper technique for acute postoperative bifurcation stenosis causing right ventricular failure after Ross procedure

    PubMed Central

    Divekar, Abhay A

    2016-01-01

    In this report, we describe a 15-year-old patient who underwent a Ross procedure for a regurgitant bicuspid aortic valve and ascending aortic dilation. After the operation was over, he could not be separated from cardiopulmonary bypass and was noted to have isolated right ventricular failure. This report takes the reader through the diagnostic evaluation, highlights the importance of invasive assessment in the immediate postoperative period, and discusses successful transcatheter intervention in the acute postoperative setting. PMID:27625524

  9. Ventricular patch endocarditis caused by Propionibacterium acnes: advantages of gallium scanning.

    PubMed

    Vandenbos, F; Roger, P M; Mondain-Miton, V; Dunais, B; Fouché, R; Kreitmann, P; Carles, D; Migneco, O; Dellamonica, P

    2001-11-01

    Propionibacterium acnes is a weakly pathogenic commensal of the skin. When isolated from blood cultures it is often considered a contaminant. However, P. acnes may be responsible for severe infections and its role in certain cases of infectious endocarditis has now been definitely established.(1) We report a case of endocarditis due to P. acnes stemming from a ventricular patch and revealed by a gallium 67 scan. PMID:11869063

  10. Unusual Manifestation of Graves' Disease: Ventricular Fibrillation

    PubMed Central

    Kobayashi, Hiroki; Haketa, Akira; Abe, Masanori; Tahira, Kazunobu; Hatanaka, Yoshinari; Tanaka, Sho; Ueno, Takahiro; Soma, Masayoshi

    2015-01-01

    Background It is well known that thyrotoxicosis causes rhythm disorders including sinus tachycardia, atrial fibrillation, and atrial flutter. Atrial fibrillation is the most common arrhythmia in thyrotoxicosis, occurring in 5-15% of patients over 60 years of age, whereas ventricular arrhythmia is an unusual manifestation. Case Report An 18-year-old Japanese woman was admitted to our emergency department because of loss of consciousness caused by ventricular fibrillation. She had been diagnosed with Graves' disease only 5 days earlier and had no other past medical history. Blood examination showed no obvious abnormality except thyrotoxicosis, and coronary angiography revealed patent coronary arteries. She was diagnosed with thyroid storm due to Graves' disease and is currently healthy during outpatient follow-up. Conclusion This case highlights that thyrotoxicosis can, albeit extremely rarely, cause ventricular fibrillation even in the absence of hypokalemia or underlying cardiovascular disease. PMID:26558239

  11. Morphologic study of left ventricular bands.

    PubMed

    Deniz, M; Kilinç, M; Hatipoglu, E S

    2004-06-01

    The presence of left ventricular bands has drawn attention to their possible clinical importance, though there are no concrete data to support their role in serious clinical diseases. We have investigated the incidence, location, microscopic and macroscopic structure of left ventricular bands in the human and animals. We examined 100 hearts: 28 human and 72 animal (dog, goat, sheep). Left ventricular bands were present in 13 of 28 (46%) human hearts and 62 of 72 (86%) animal hearts. The bands usually extended from the interventricular septum to the free walls in human hearts and from the papillary muscles to the interventricular septum in animal hearts. They were composed of muscle tissue in various proportions in human and dog hearts, and of connective and conductive tissue in sheep and goat hearts. PMID:14648038

  12. Respiratory acoustic impedance in left ventricular failure.

    PubMed

    Depeursinge, F B; Feihl, F; Depeursinge, C; Perret, C H

    1989-12-01

    The measurement of respiratory acoustic impedance (Zrs) by forced pseudorandom noise provides a simple means of assessing respiratory mechanics in nonintubated intensive care patients. To characterize the lung mechanical alterations induced by acute vascular congestion of the lung, Zrs was measured in 14 spontaneously breathing patients hospitalized for acute left ventricular failure. The Zrs data in the cardiac patients were compared with those of 48 semirecumbent normal subjects and those of 23 sitting asthmatic patients during allergen-induced bronchospasm. In the patients with acute left ventricular failure, the Zrs abnormalities noted were an excessive frequency dependence of resistance from 10 to 20 Hz and an abnormally low reactance at all frequencies, abnormalities qualitatively similar to those observed in the asthmatic patients but of lesser magnitude. Acute lung vascular congestion modifies the acoustic impedance of the respiratory system. Reflex-induced bronchospasm might be the main mechanism altering respiratory acoustic impedance in acute left ventricular failure. PMID:2582846

  13. Right Ventricular Cardiomyopathy Meeting the Arrhythmogenic Right Ventricular Dysplasia Revised Criteria? Don't Forget Sarcoidosis!

    PubMed Central

    Vasaturo, Sabina; Ploeg, David E.; Buitrago, Guadalupe; Zeppenfeld, Katja; Veselic-Charvat, Maud

    2015-01-01

    A 53-year-old woman was referred for ventricular fibrillation with resuscitation. A CT-angiography showed signs of a right ventricular enlargement without obvious cause. A cardiac MRI demonstrated a dilated and hypokinetic right ventricle with extensive late gadolinium enhancement. Arrhythmogenic right ventricular dysplasia (ARVD) was suspected according to the "revised ARVD task force criteria". An endomyocardial biopsy was inconclusive. The patient developed purulent pericarditis after epicardial ablation therapy and died of toxic shock syndrome. The post-mortem pathologic examination demonstrated sarcoidosis involving the heart, lungs, and thyroid gland. PMID:25995699

  14. Premature Ventricular Complexes in Apparently Normal Hearts.

    PubMed

    Luebbert, Jeffrey; Auberson, Denise; Marchlinski, Francis

    2016-09-01

    Premature ventricular complexes (PVCs) are consistently associated with worse prognosis and higher morbidity and mortality. This article reviews PVCs and their presentation in patients with an apparently normal heart. Patients with PVCs may be completely asymptomatic, whereas others may note severely disabling symptoms. Cardiomyopathy may occur with frequent PVCs. Diagnostic work-up is directed at obtaining 12-lead ECG to characterize QRS morphology, Holter monitor to assess frequency, and echo and advanced imaging to assess for early cardiomyopathy and exclude structural heart disease. Options for management include watchful waiting, medical therapy, or catheter ablation. Malignant variants of PVCs may induce ventricular fibrillation even in a normal heart. PMID:27521085

  15. Mechanisms of transplant right ventricular dysfunction.

    PubMed Central

    Van Trigt, P; Bittner, H B; Kendall, S W; Milano, C A

    1995-01-01

    OBJECTIVE: Right ventricular (RV) dysfunction remains the leading cause of early mortality after cardiac transplantation. The effect of brain death and subsequent hypothermic cardioplegic arrest and storage on subsequent post-transplant right ventricular function was examined. SUMMARY BACKGROUND DATA: Right ventricular dysfunction in the donor heart usually is attributed to failure of the donor right ventricle to adapt to the sudden increase in afterload (pulmonary vascular resistance) in the recipient. Strategies to improve ventricular mechanics in the postoperative period are aimed at reducing pulmonary vascular resistance with vasodilators or augmenting right ventricular contractility with inotropic agents. Events occurring in the donor heart (brain death, hypothermic cardioplegic arrest, and storage) also may be directly related to post-transplant RV dysfunction. METHODS: A canine model of brain death and orthotopic cardiac transplantation was used. A dynamic pressure-volume analysis of RV mechanics was performed using micromanometers and sonomicrometric dimension transducers. Systolic function was assessed by measurement of preload recruitable stroke work (PRSW). Brain death was induced in 17 dogs by inflation of an intracranial balloon. Right ventricular function then was assessed serially to 6 hours (PRSW). Right ventricular adrenergic beta receptor density and function was sampled at control and after 6 hours of brain death. The effect of cardioplegic arrest and hypothermic storage was assessed in a second group of 17 dogs, using the same instrumentation and method of RV analysis. RESULTS: A significant decrease in right ventricular PRSW occurred after brain death, with the average decrease being 37% +/- 10.4% from the control. The RV myocardial beta adrenergic receptor density did not significantly change (253 +/- 34 fmol/ng control vs. 336 +/- 54 fmol/ng after brain death). The adenylyl cyclase activity of the RV beta receptor was assessed and was not

  16. Pattern Organization of Premature Ventricular Heartbeats

    NASA Astrophysics Data System (ADS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Ivanov, Plamen; Stanley, H. Eugene; Stanley, Gene; Goldberger, Ary L.

    2000-03-01

    Increased number of premature (abnormal) ventricular beats in a record of heartbeat intervals are known to be associated with an advanced stage of pathology (e.g. congestive heart failure). These abnormal beats usually occur in repeated bursts for relatively short periods of time. Here we ask the question if particular abnormal patterns appear throughout records of heartbeat intervals. We study the temporal organization of specific patterns of ventricular beats in long 24 hour records and their relation to different stages of disease. We analyze the statistical properties of such patterns and combination of patterns by means of crosscorrelation matrices.

  17. Metastatic breast cancer with right ventricular erosion.

    PubMed

    Chou, Wei-Han; Chi, Nai-Hsin; Wang, Yi-Chia; Huang, Chi-Hsiang

    2016-03-01

    Cancer that has metastasized to the heart and pericardium has a dismal outcome. Individualized treatment to preserve the quality of life and reduce surgical mortality is important. We describe a 57-year old woman who had a recurrence of breast cancer 23 years after the initial complete treatment. Cardiac metastasis with poor anterior chest wall healing led to right ventricular rupture, which caused hypovolaemic shock. The right ventricular wall defect was repaired with a percutaneous patch and a myocutaneous flap without cardiopulmonary bypass. The patient was discharged home after intensive wound care. Our patient shows that even with complete initial treatment, clinicians should be alert for the recurrence of breast cancer. PMID:25890934

  18. Ventricular Tachycardia in Congenital Pulmonary Stenosis.

    PubMed

    Ruckdeschel, Emily Sue; Schuller, Joseph; Nguyen, Duy Thai

    2016-03-01

    With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Although congenital pulmonary valve stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope. PMID:26920196

  19. Impact of Ancillary Subunits on Ventricular Repolarization

    PubMed Central

    Abbott, Geoffrey W.; Xu, Xianghua; Roepke, Torsten K.

    2007-01-01

    Voltage-gated potassium (Kv) channels generate the outward K+ ion currents that constitute the primary force in ventricular repolarization. Kv channels comprise tetramers of pore-forming α subunits and, in probably the majority of cases in vivo, ancillary or β subunits that help define the properties of the Kv current generated. Ancillary subunits can be broadly categorized as cytoplasmic or transmembrane, and can modify Kv channel trafficking, conductance, gating, ion selectivity, regulation and pharmacology. Because of their often profound effects on Kv channel function, studies of the molecular correlates of ventricular repolarization must take into account ancillary subunits as well as α subunits. Cytoplasmic ancillary subunits include the Kvβ subunits, which regulate a range of Kv channels and may link channel gating to redox potential; and the KChIPs, which appear most often associated with Kv4 subfamily channels that generate the ventricular Ito current. Transmembrane ancillary subunits include the MinK-related proteins (MiRPs) encoded by KCNE genes, which modulate members of most Kv α subunit subfamilies; and the putative 12-transmembrane domain KCR1 protein which modulates hERG. In some cases, such as the ventricular IKs channel complex, it is well-established that the KCNQ1 α subunit must co-assemble with the MinK (KCNE1) single transmembrane domain ancillary subunit for recapitulation of the characteristic, unusually slowly-activating IKs current. In other cases it is not so clear-cut, and in particular the roles of the other MinK-related proteins (MiRPs 1–4) in regulating cardiac Kv channels such as KCNQ1 and hERG in vivo are under debate. MiRP1 alters hERG function and pharmacology, and inherited MiRP1 mutations are associated with inherited and acquired arrhythmias, but controversy exists over the native role of MiRP1 in regulating hERG (and therefore ventricular IKr) in vivo. Some ancillary subunits may exhibit varied expression to shape

  20. Arrhythmias in two patients with left ventricular bypass transplants.

    PubMed Central

    Kennelly, B M; Corte, P; Losman, J; Barnard, C N

    1976-01-01

    Two patients who underwent left ventricular bypass transplants are described. Both patients sustained postoperative rhythm disturbances of their own hearts during sinus rhythm of the donor hearts. Illustrative examples of atrial flutter, ventricular flutter, ventricular fibrillation, blocked atrial extrasystoles, and double ventricular parasystole in the recipient hearts are presented. The patients tolerated all these arrhythmias well during uninterrupted sinus rhythm in the donor heart. The problems in interpretation of arrhythmias in the presence of two hearts are discussed. Images PMID:788729

  1. Is ventricular ectopy a legitimate target for ablation?

    PubMed Central

    Gumbrielle, T; Bourke, J P; Furniss, S S

    1994-01-01

    Radiofrequency ablation has an established role in the treatment of non-ischaemic ventricular tachycardia. A few patients present with symptomatic but benign ventricular ectopy that can be mapped to the right ventricular outflow tract. The successful use of radiofrequency ablation in a patient with drug resistant, symptomatic ventricular ectopy is reported. Radiofrequency ablation may have a useful role in more benign arrhythmias. PMID:7818971

  2. Outcomes of Catheter Ablation of Ventricular Tachycardia in the Setting of Structural Heart Disease.

    PubMed

    Betensky, B P; Marchlinski, F E

    2016-07-01

    Sustained ventricular tachycardias are common in the setting of structural heart disease, either due to prior myocardial infarction or a variety of non-ischemic etiologies, including idiopathic dilated cardiomyopathy, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. Over the past two decades, percutaneous catheter ablation has evolved dramatically and has become an effective tool for the control of ventricular arrhythmias. Single and multicenter observational studies as well as several prospective randomized trials have begun to investigate long-term outcomes after catheter ablation procedures. These studies encompass a wide range of mapping and ablation techniques, including conventional activation mapping/entrainment criteria, substrate modification guided by pacemapping, late potential and abnormal electrogram ablation, scar de-channeling, and core isolation. While large-scale, multicenter prospective randomized clinical trials are somewhat limited, the published data demonstrate favorable outcomes with respect to a reduction in overall ventricular tachycardia (VT) burden, reduction of implantable cardioverter defibrillator (ICD) shocks, and discontinuation of anti-arrhythmic medications across varying disease subtypes and convincingly support the use of catheter ablation as the standard of care for many patients with VT in the setting of structural heart disease. PMID:27234813

  3. Left-ventricular cavity automated-border detection using an autocovariance technique in echocardiography

    NASA Astrophysics Data System (ADS)

    Morda, Louis S.; Konofagou, Elisa E.

    2005-04-01

    Left-ventricular (LV) segmentation is essential in the early detection of heart disease, where left-ventricular wall motion is being tracked in order to detect ischemia. In this paper, a new method for automated segmentation of the left-ventricular chamber is described. An autocorrelation-based technique isolates the LV cavity from the myocardial wall on 2-D slices of 3D short-axis echocardiograms. A morphological closing function and median filtering are used to generate a uniform border. The proposed segmentation technique is designed to be used in identifying the endocardial border and estimating the motion of the endocardial wall over a cardiac cycle. To this purpose, the proposed technique is particularly successful in border delineation by tracing around structures like papillary muscles and the mitral valve, which constitute the typical obstacle in LV segmentation techniques. The results using this new technique are compared to the manual detection results in short-axis views obtained at the papillary muscle level from 3D datasets in human and canine experiments in vivo. Qualitatively, the automatically-detected borders are highly comparable to the manually-detected borders enclosing regions in the left-ventricular cavity with a relative error within the range of 4.2% - 6%. The new technique constitutes, thus, a robust segmentation method for automated segmentation of endocardial borders and suitable for wall motion tracking for automated detection of ischemia.

  4. A murine experimental model for the mechanical behaviour of viable right-ventricular myocardium

    PubMed Central

    Valdez-Jasso, Daniela; Simon, Marc A; Champion, Hunter C; Sacks, Michael S

    2012-01-01

    Although right-ventricular function is an important determinant of cardio-pulmonary performance in health and disease, right ventricular myocardium mechanical behaviour has received relatively little attention. We present a novel experimental method for quantifying the mechanical behaviour of transmurally intact, viable right-ventricular myocardium. Seven murine right ventricular free wall (RVFW) specimens were isolated and biaxial mechanical behaviour measured, along with quantification of the local transmural myofibre and collagen fibre architecture. We developed a complementary strain energy function based method to capture the average biomechanical response. Overall, murine RVFW revealed distinct mechanical anisotropy. The preferential alignment of the myofibres and collagen fibres to the apex-to-outflow-tract direction was consistent with this also being the mechanically stiffer axis. We also observed that the myofibre and collagen fibre orientations were remarkably uniform throughout the entire RVFW thickness. Thus, our findings indicate a close correspondence between the tissue microstructure and biomechanical behaviour of the RVFW myocardium, and are a first step towards elucidating the structure–function of non-contracted murine RVFW myocardium in health and disease. PMID:22848044

  5. Left ventricular pseudoaneurysm perceived as a left lung mass

    PubMed Central

    Yaliniz, Hafize; Gocen, Ugur; Atalay, Atakan; Salih, Orhan Kemal

    2016-01-01

    Left ventricular pseudoaneurysm is a rare complication of aneurysmectomy. We present a case of a surgically treated left ventricular pseudoaneurysm, which was diagnosed three years after coronary artery bypass grafting and left ventricular aneurysmectomy. The presenting symptoms, diagnostic evaluation, and surgical repair are described.

  6. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that assists... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ventricular bypass (assist) device....

  7. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that assists... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular bypass (assist) device....

  8. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that assists... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ventricular bypass (assist) device....

  9. [Right ventricular dysplasia and dilated cardiomyopathy observed by radionuclide images].

    PubMed

    Takamura, I; Ando, J; Miyamoto, A; Kobayashi, T; Sakamoto, S; Yasuda, H

    1985-12-01

    Four cases of right ventricular dysplasia (RVD) and 28 cases of dilated cardiomyopathy (DCM) were studied. RVD was characterized clinically by syncope, sustained recurrent ventricular tachycardia with left bundle branch block patterns on the surface electrocardiogram, and right heart failure. Furthermore, moderate to severe dilatation of the right ventricle and depressed right ventricular function were apparent on radionuclide angiography. However, left ventricular dilatation and depressed left ventricular function were documented in DCM. Right ventricular volume was proportional to left ventricular volume in DCM, however, right ventricular volume was disproportionately greater in RVD. On the T1-201 perfusion image, left ventricular perfusion defects were delineated in 10 of 26 patients with DCM, and in one of four RVD patients. During two to eight year follow-up periods, six patients died suddenly five of whom had left ventricular perfusion defects. However, in 19 patients without left ventricular perfusion defects, only one sudden death was observed. A connecting link between sudden death and left ventricular perfusion defect is suggested. PMID:3841888

  10. Adverse ventricular-ventricular interactions in right ventricular pressure load: Insights from pediatric pulmonary hypertension versus pulmonary stenosis.

    PubMed

    Driessen, Mieke M P; Hui, Wei; Bijnens, Bart H; Dragulescu, Andreea; Mertens, Luc; Meijboom, Folkert J; Friedberg, Mark K

    2016-06-01

    Right ventricular (RV) pressure overload has a vastly different clinical course in children with idiopathic pulmonary arterial hypertension (iPAH) than in children with pulmonary stenosis (PS). While RV function is well recognized as a key prognostic factor in iPAH, adverse ventricular-ventricular interactions and LV dysfunction are less well characterized and the pathophysiology is incompletely understood. We compared ventricular-ventricular interactions as hypothesized drivers of biventricular dysfunction in pediatric iPAH versus PS Eighteen iPAH, 16 PS patients and 18 age- and size-matched controls were retrospectively studied. Cardiac cycle events were measured by M-mode and Doppler echocardiography. Measurements were compared between groups using ANOVA with post hoc Dunnet's or ANCOVA including RV systolic pressure (RVSP; iPAH 96.8 ± 25.4 mmHg vs. PS 75.4 ± 18.9 mmHg; P = 0.011) as a covariate. RV-free wall thickening was prolonged in iPAH versus PS, extending beyond pulmonary valve closure (638 ± 76 msec vs. 562 ± 76 msec vs. 473 ± 59 msec controls). LV and RV isovolumetric relaxation were prolonged in iPAH (P < 0.001; LV 102.8 ± 24.1 msec vs. 63.1 ± 13.7 msec; RV 95 [61-165] vs. 28 [0-43]), associated with adverse septal kinetics; characterized by rightward displacement in early systole and leftward displacement in late RV systole (i.e., early LV diastole). Early LV diastolic filling was decreased in iPAH (73 ± 15.9 vs. PS 87.4 ± 14.4 vs. controls 95.8 ± 12.5 cm/sec; P = 0.004). Prolonged RVFW thickening, prolonged RVFW isovolumetric times, and profound septal dyskinesia are associated with interventricular mechanical discoordination and decreased early LV filling in pediatric iPAH much more than PS These adverse mechanics affect systolic and diastolic biventricular efficiency in iPAH and may form the basis for worse clinical outcomes. We used clinically derived data to study the pathophysiology of ventricular-ventricular

  11. Left Ventricular Aneurysm and Ventricular Tachycardia as Initial Presentation of Cardiac Sarcoidosis

    PubMed Central

    Jmeian, Ashraf; Thawabi, Mohammad; Goldfarb, Irvin; Shamoon, Fayez

    2015-01-01

    Context: Cardiac sarcoidosis (CS) is a rare, potentially fatal disease. It has a wide range of clinical presentations that range from asymptomatic electrocardiogram changes to sudden cardiac death. Ventricular aneurysms and ventricular tachycardia are seen late in the disease, and are rarely the presenting manifestation of the disease. Diagnosis of CS is challenging and often missed or delayed. Case Report: We report a 35-year-old patient who presented with sustained ventricular tachycardia and ST-elevation on electrocardiogram. Cardiac catheterization showed normal coronaries and left ventricular aneurysm. Subsequent 2D-echocardiography showed an infiltrative disease pattern. Cardiac MRI was done and showed late gadolinium enhancement in the septum, apex and lateral wall. The patient was diagnosed with cardiac sarcoidosis and treated with immune suppression and antiarrhythmic agent. In addition underwent AICD implantation. Conclusion: Our case highlights the importance of suspecting cardiac sarcoidosis in young patients presenting with electrocardiogram changes, and present an atypical presentation of this disease. PMID:25839003

  12. Clinical efficacy of intravenous amiodarone in the short term treatment of recurrent sustained ventricular tachycardia and ventricular fibrillation.

    PubMed Central

    Schützenberger, W; Leisch, F; Kerschner, K; Harringer, W; Herbinger, W

    1989-01-01

    The clinical efficacy of intravenous amiodarone in terminating sustained ventricular tachycardia and in preventing recurrences of ventricular tachycardia and ventricular fibrillation was evaluated in 26 patients. All of them presented with organic heart disease accompanied by depressed left ventricular function. Intravenous amiodarone terminated spontaneous ventricular tachycardia in eight of 19 patients. Fifteen of the 26 patients had had at least one episode of ventricular tachycardia or ventricular fibrillation each day in the period immediately before the intravenous administration of amiodarone. Amiodarone controlled ventricular tachycardia or ventricular fibrillation in nine of these 15 patients; in three further cases it was successful when supplemented by additional administration of a previously ineffective antiarrhythmic drug and ventricular pacing. Two patients died despite these measures. In one, the amiodarone infusion had to be stopped because of an arrhythmogenic effect. Sustained deterioration of haemodynamic function or of pre-existing intraventricular conduction disturbances was never seen. Intravenous amiodarone was effective in terminating sustained ventricular tachycardia and in preventing frequent episodes of ventricular arrhythmia that were refractory to other antiarrhythmic drugs. PMID:2590589

  13. Induction of ventricular fibrillation predicts sudden death in patients treated with amiodarone because of ventricular tachyarrhythmias after a myocardial infarction.

    PubMed Central

    Rodríguez, L. M.; Sternick, E. B.; Smeets, J. L.; Timmermans, C.; den Dulk, K.; Oreto, G.; Wellens, H. J.

    1996-01-01

    OBJECTIVE--To examine the value of programmed electrical stimulation of the heart in predicting sudden death in patients receiving amiodarone to treat ventricular tachyarrhythmias after myocardial infarction. DESIGN--Consecutive patients; retrospective study. SETTING--Referral centre for cardiology, academic hospital. PATIENTS--106 patients with ventricular tachycardia (n = 77) or ventricular fibrillation (n = 29) late after myocardial infarction. INTERVENTIONS--Programmed electrical stimulation was performed while on amiodarone treatment for at least one month. MEASUREMENTS AND MAIN RESULTS--In 80/106 patients either ventricular fibrillation (n = 15) or sustained monomorphic ventricular tachycardia (n = 65) was induced. After a mean follow up of 50 (SD 40) months (1-144), 11 patients died suddenly and two used their implantable cardioverter debfibrillator. By multivariate analysis two predictors for sudden death were found: (1) inducibility of ventricular fibrillation under amiodarone treatment (P << 0.001), and (2) a left ventricular ejection fraction of < 40% (P < 0.05). The survival rate at one, two, three, and five years was 70%, 62%, 62%, and 40% respectively for patients in whom ventricular fibrillation was induced, and 98%, 96%, 94%, 94% for patients with induced sustained monomorphic ventricular tachycardia. Where there was no sustained arrhythmia, five year survival was 100%. CONCLUSIONS--In patients receiving amiodarone because of life threatening ventricular arrhythmias after myocardial infarction, inducibility of ventricular fibrillation, but not of sustained monomorphic ventricular tachycardia, indicates a high risk of sudden death. PMID:8624866

  14. Radionuclide analysis of right and left ventricular response to exercise in patients with atrial and ventricular septal defects

    SciTech Connect

    Peter, C.A.; Bowyer, K.; Jones, R.H.

    1983-03-01

    In patients with ventricular or atrial septal defect, the ventricle which is chronically volume overloaded might not appropriately respond to increased demand for an augmentation in output and thereby might limit total cardiac function. In this study we simultaneously measured right and left ventricular response to exercise in 10 normal individuals, 10 patients with ventricular septal defect (VSD), and 10 patients with atrial septal defect (ASD). The normal subjects increased both right and left ventricular ejection fraction, end-diastolic volume, and stroke volume to achieve a higher cardiac output during exercise. Patients with VSD failed to increase right ventricular ejection fraction, but increased right ventricular end-diastolic volume and stroke volume. Left ventricular end-diastolic volume did not increase in these patients but ejection fraction, stroke volume, and forward left ventricular output achieved during exercise were comparable to the response observed in healthy subjects. In the patients with ASD, no rest-to-exercise change occurred in either right ventricular ejection fraction, end-diastolic volume, or stroke volume. In addition, left ventricular end-diastolic volume failed to increase, and despite an increase in ejection fraction, left ventricular stroke volume remained unchanged from rest to exercise. Therefore, cardiac output was augmented only by the heart rate increase in these patients. Right ventricular function appeared to be the major determinant of total cardiac output during exercise in patients with cardiac septal defects and left-to-right shunt.

  15. Comparison of effectiveness of right ventricular septal pacing versus right ventricular apical pacing.

    PubMed

    Cano, Oscar; Osca, Joaquín; Sancho-Tello, María-José; Sánchez, Juan M; Ortiz, Víctor; Castro, José E; Salvador, Antonio; Olagüe, José

    2010-05-15

    Chronic right ventricular apical pacing (RVAP) has been associated with negative hemodynamic and clinical effects. The aim of the present study was to compare RVAP with right ventricular septal pacing (RVSP) in terms of echocardiographic features and clinical outcomes. A total of 93 patients without structural heart disease and with an indication for a permanent pacemaker were randomly assigned to receive a screw-in lead either in the RV apex (n = 46) or in the RV mid-septum (n = 47). The patients were divided into 3 subgroups according to the percentage of ventricular pacing: control group (n = 21, percentage of ventricular pacing < or =10%), RVAP group (n = 28), or RVSP group (n = 32; both latter groups had a percentage of ventricular pacing >10%). The RVAP group had more intraventricular dyssynchrony and a trend toward a worse left ventricular ejection fraction compared to the RVSP and control groups at 12 months of follow-up (maximal delay to peak systolic velocity between any of the 6 left ventricular basal segments was 57.8 +/- 38.2, 35.5 +/- 20.6, and 36.5 +/- 17.8 ms for RVAP, RVSP, and control group, respectively; p = 0.006; mean left ventricular ejection fraction 62.9 +/- 7.9%, 66.5 +/- 7.2%, and 66.6 +/- 7.2%, respectively, p = 0.14). Up to 48.1% of the RVAP patients showed significant intraventricular dyssynchrony compared to 19.4% of the RVSP patients and 23.8% of the controls (p = 0.04). However, no overt clinical benefits from RVSP were found. In conclusion, RVAP was associated with increased dyssynchrony compared to the RVSP and control patients. RVSP could represent an alternative pacing site in selected patients to reduce the harmful effects of traditional RVAP. PMID:20451689

  16. Intramural Reentrant Ventricular Tachycardia in a Patient with Severe Hypertensive Left Ventricular Hypertrophy

    PubMed Central

    Lin, Chin-Yu; Chung, Fa-Po; Lin, Yenn-Jiang

    2015-01-01

    We describe the case of a patient with severe hypertensive left ventricular hypertrophy and sustained hemodynamically unstable ventricular tachycardia (VT). Entrainment was demonstrated in the electrophysiological study. Activation mapping and pacemapping identified the location of the intramural reentrant VT with the exit site close to the epicardium. However, VT persisted after ablation at the epicardial exit site. Successful ablation was performed endocardially at the corresponding position. PMID:26617657

  17. Left ventricular mass: Myxoma or thrombus?

    PubMed Central

    Raut, Monish S.; Maheshwari, Arun; Dubey, Sumir; Joshi, Sandip

    2015-01-01

    Patient with embolic episode should always be evaluated for cardiac mass. Mass in left ventricular can be a myxoma or thrombus even in a normal functioning heart. In either case, mobile mass with embolic potential should be surgically resected. PMID:25566719

  18. [Mapping and ablation of malignant ventricular arrhythmias].

    PubMed

    Hocini, M; Jais, P; Sacher, F; Reuter, S; Clémenty, J; Haïssaguerre, M

    2005-12-01

    Endocavitary investigations showed that the ventricular extrasystoles originated in the common ventricular myocardium (pulmonary infundibulum) in only 9 cases whereas the majority arose from the Parkinje system either on the anterior wall of the right ventricle or in septal region of the left ventricle. The extrasystoles arising from the Parkinje system and pulmonary infundibulum differed in their duration and polymorphism (128 +/- 18 ms vs 145 +/- 13 ms, p = 0.05; 3.3 +/- 2.7 morphologies vs 1.1 +/- 0.4, p < 0.001, respectively). During the extrasystoles, the local Pukinje potential preceded the ventricular activation by variable intervals, some of which were very long, up to 150 ms. Seven applications of radiofrequency were delivered on average per patient on the most distal part of the Purkinje system leading to ablation of the specific activation. The clinical results were spectacular: 88% of patients had no further episodes of ventricular fibrillation as demonstrated by analysis of the defibrillator with an average follow-up period of more than 34 months. PMID:16433241

  19. Myocardial infarction complicated by ventricular septal rupture.

    PubMed

    Sahjian, Michael; Ventriglia, Rich; Bolton, Lauri

    2012-01-01

    Transporting patients with an ST segment elevation myocardial infarction (STEMI) is a fairly common practice for most critical care transport teams. When a STEMI is complicated by ventricular septal rupture, the care can become more challenging, especially if the rupture is not yet diagnosed. This article describes such a transport and reviews the pathophysiology of the process along with treatment options. PMID:22225564

  20. Carcinoid Syndrome-Induced Ventricular Tachycardia

    PubMed Central

    Ahmadjee, Abdulmohsin; Morshedzadeh, Jack H.; Ranjan, Ravi

    2016-01-01

    Introduction. Carcinoid tumors are rare neuroendocrine malignancies that secrete multiple bioactive substances. These bioactive substances are responsible for the carcinoid syndrome characterized by diarrhea, flushing, syncope, and right-sided valvular heart disease. Previous case reports have described carcinoid syndrome associated with coronary vasospasm and the well-characterized carcinoid heart disease. Case. Our patient is a 73-year-old female with complex past medical history most notable for metastatic carcinoid tumors diagnosed in 2013-05. She initially presented in 2014-09 with syncope and dizziness associated with sinus pause on an event monitor. She received a pacemaker given normal left ventricular function and was discharged. However, she was readmitted with similar symptoms corresponding to multiple episodes of ventricular tachycardia. She was started on high-dose beta blockade and has had no recurrence of arrhythmia over a follow-up period of 12 months. Conclusion. We hypothesize that the patient's ventricular tachycardia was mediated by the multiple bioactive substances secreted by her carcinoid tumors. Her carcinoid tumor biomarkers were elevated and other explanations for arrhythmia were investigated and ruled out. To our knowledge, this is the first case of ventricular tachycardia mediated by carcinoid syndrome and suppressed by beta-blocker. Further investigation into this relationship is needed. PMID:27088017

  1. Ventricular myocardial architecture in marine fishes.

    PubMed

    Sanchez-Quintana, D; Hurle, J M

    1987-03-01

    The fiber architecture of the ventricular myocardium has been studied in elasmobranch (Isurus oxyrhinchus, Galeorhinus galeus, Prionace glauca) and teleost (Xiphias gladius, Thunnus thynnus, Thunnus alalunga) fish species with hearts displaying mixed types of ventricular musculature (compact and trabecular). In all cases, the compact myocardium is organized in layers of fiber bundles with an orderly arrangement within the ventricular walls. The number of these layers appears to be dependent on the relative thickness of the compact myocardium. Differences in the pattern of myocardial fiber arrangement were observed among the different fish species. In elasmobranchs the compact myocardium at the level of the atrioventricular orifice is continuous with the trabeculated myocardium. Furthermore, in elasmobranchs the trabeculated myocardium displays a precise arrangement in arcuate trabeculae running from the auriculoventricular to the conoventricular orifices. In teleosts, the compact myocardium is independent of the trabeculated myocardium and a large number of fibers insert into the bulboventricular fibrous ring. The trabeculated myocardium in these species displays an anarchic arrangement except at the level of the bulboventricular orifice, where the fibers tend to be aligned longitudinally, also being inserted into the fibrous ring. Minor differences, consisting mainly of the presence of extra bundles of fibers, were also observed among different individuals of the same species. The possible relationship between myocardial fiber architecture and ventricular shape is discussed. PMID:3578842

  2. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  3. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  4. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  5. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  6. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  7. Catheter ablation of ventricular tachycardia related to a septo-apical left ventricular aneurysm

    PubMed Central

    Rosu, Radu; Cismaru, Gabriel; Muresan, Lucian; Puiu, Mihai; Andronache, Marius; Gusetu, Gabriel; Pop, Dana; Mircea, Petru-Adrian; Zdrenghea, Dumitru

    2015-01-01

    A 60-year-old male patient with previous myocardial infarction (30 years ago) presented to our cardiology department for sustained monomorphic ventricular tachycardia. The patient presented multiple episodes of tachycardia treated by his internal cardiac defibrillator. Radiofrequency ablation was proposed as curative treatment. The mechanism of the ventricular tachycardia was demonstrated by electrophysiological study using three-dimensional mapping system: Carto 3 (Biosense Webster). Ventricular tachycardia was induced either mechanically or by programmed ventricular stimulation. The tachycardia cycle length was 380 msec. The voltage map confirmed the presence of the septo-apical aneurysm with a local voltage < 0.5 mV. Activation mapping revealed a figure-in-8 circuit of VT with the entrance point inside the dense scar and the exit point at the border zone (between the aneurysm and the healthy tissue of the left ventricular septo-apical region). Radiofrequency energy was delivered at the isthmus of the tachycardia rendering it uniducible by programmed ventricular stimulation. PMID:26770613

  8. Fontan-Like Hemodynamics Complicated With Ventricular Fibrillation During Left Ventricular Assist Device Support.

    PubMed

    Imamura, Teruhiko; Kinugawa, Koichiro; Nitta, Daisuke; Kinoshita, Osamu; Nawata, Kan; Ono, Minoru

    2016-07-27

    We experienced a patient who had received an implantable continuous-flow left ventricular assist device (LVAD) (HeartMate II, Thoratec Corp, Pleasanton, CA, USA) and was admitted to our hospital because of repeated ventricular tachyarrhythmias refractory to electrical defibrillation as well as intensive pharmacological therapy. We decided to discontinue defibrillating, but under ventricular fibrillation his hemodynamics were maintained without end-organ dysfunction during LVAD support (mean right atrial pressure 18 mmHg; pulmonary vascular resistance 1.6 WU; pulmonary capillary wedge pressure 11 mmHg; cardiac index 2.04 L/minute/m(2)) due to optimization of the rotation speed (from 8800 to 9200 rpm). Such "Fontan-like circulation" could be accomplished by adequate volume control, lowering pulmonary vascular resistance, and potent LV blood removal by optimal rotation speed of the LVAD, although the precise conditions to maintain the Fontan-like circulation during LVAD therapy remained uncertain. Considering the severe donor heart shortage and high degree of difficulty of the catheter ablation procedure to manage ventricular tachyarrhythmias, constructing a Fontan-like circulation in the presence of ventricular tachyarrhythmias may be one unique strategy. Longterm prognosis in patients with sustained ventricular tachyarrhythmias during LVAD support would be a future concern. PMID:27385606

  9. Surgical management of left ventricular thrombus following severe dehydration.

    PubMed

    Tanaka, Yuki; Nie, Masaki; Yamamoto, Nobuyuki; Ohara, Kuniyoshi; Miyaji, Kagami

    2016-08-01

    We experienced a case involving a left ventricular ball-like thrombus caused by severe following a 150 mile cycling road race. The patient had lower-limb arterial obstruction due to systemic thromboembolism on admission with no significant embolism, including the cerebral arteries, were detected. Left ventricular wall motion was good with no evidence of left and right coronary artery occlusion; therefore, we performed emergency left ventricular thrombectomy. Although there are many reports of left ventricular thrombus following acute myocardial infarction, dehydration is a very rare cause. Herein, we describe the surgical and management approaches to the treatment of left ventricular thrombectomy in this case. PMID:26266631

  10. Left ventricular function in chronic aortic regurgitation

    SciTech Connect

    Iskandrian, A.S.; Hakki, A.H.; Manno, B.; Amenta, A.; Kane, S.A.

    1983-06-01

    Left ventricular performance was determined in 42 patients with moderate or severe aortic regurgitation during upright exercise by measuring left ventricular ejection fraction and volume with radionuclide ventriculography. Classification of the patients according to exercise tolerance showed that patients with normal exercise tolerance (greater than or equal to 7.0 minutes) had a significantly higher ejection fraction at rest (probability (p) . 0.02) and during exercise (p . 0.0002), higher cardiac index at exercise (p . 0.0008) and lower exercise end-systolic volume (p . 0.01) than did patients with limited exercise tolerance. Similar significant differences were noted in younger patients compared with older patients in ejection fraction at rest and exercise (both p . 0.001) and cardiac index at rest (p . 0.03) and exercise (p . 0.0005). The end-diastolic volume decreased during exercise in 60% of the patients. The patients with a decrease in volume were significantly younger and had better exercise tolerance and a larger end-diastolic volume at rest than did patients who showed an increase in volume. The mean corrected left ventricular end-diastolic radius/wall thickness ratio was significantly greater in patients with abnormal than in those with normal exercise reserve (mean +/- standard deviation 476 +/- 146 versus 377 +/- 92 mm Hg, p less than 0.05). Thus, in patients with chronic aortic regurgitation: 1) left ventricular systolic function during exercise was related to age, exercise tolerance and corrected left ventricular end-diastolic radius/wall thickness ratio, and 2) the end-diastolic volume decreased during exercise, especially in younger patients and patients with normal exercise tolerance or a large volume at rest.

  11. Two-dimensional echocardiographic features of right ventricular infarction

    SciTech Connect

    D'Arcy, B.; Nanda, N.C.

    1982-01-01

    Real-time, two-dimensional echocardiographic studies were performed in 10 patients with acute myocardial infarction who had clinical features suggestive of right ventricular involvement. All patients showed right ventricular wall motion abnormalities. In the four-chamber view, seven patients showed akinesis of the entire right ventricular diaphragmatic wall and three showed akinesis of segments of the diaphragmatic wall. Segmental dyskinetic areas involving the right ventricular free wall were identified in four patients. One patient showed a large right ventricular apical aneurysm. Other echocardiographic features included enlargement of the right ventricle in eight cases, paradoxical ventricular septal motion in seven cases, tricuspid incompetence in eight cases, dilation of the stomach in four cases and localized pericardial effusion in two cases. Right ventricular infarction was confirmed by radionuclide methods in seven patients, at surgery in one patient and at autopsy in two patients.

  12. Increased dispersion of ventricular repolarization and ventricular tachyarrhythmias in the globally ischaemic rabbit heart.

    PubMed

    Kurz, R W; Xiao-Lin, R; Franz, M R

    1993-11-01

    Contemporary concepts of ischaemic ventricular tachyarrhythmias (VTA) are based on increased electrophysiological heterogeneity of the myocardium. We developed a multi-site monophasic action potential recording system for an isolated rabbit heart to study the effects of global ischaemia on the electrophysiological properties at different ventricular sites simultaneously. The hearts were paced from the right ventricle (RV), and conduction time (CT), action potential duration (APD) and total repolarization time (TRT = [CT + APD]) were measured during normal perfusion and ischaemia. The dispersion of these parameters was calculated as the maximal difference between simultaneous recordings. Inducibility of VTA by programmed extrastimulation (ES) was investigated under normal and ischaemic conditions. During global ischaemia, CT increased progressively, showing a faster and greater increase at the left ventricle (LV) than at the RV. After 10 min the prolongation of CT reached a plateau at the LV while it continued to rise in the RV. The dispersion of CT increased from 14.5 +/- 2.7 ms during normal perfusion to a maximum of 79.8 +/- 17.2 ms after 14 min of ischaemia (P < 0.0001). APD was uniform at the three sites (190.9 +/- 10.2, 185.0 +/- 8.6 and 179.3 +/- 9.8 ms, ns) during normal perfusion but changed non-uniformly during ischaemia. There was a transient lengthening of APD until 1 and 3 min of ischaemia at the LV sites followed by a rapid shortening of APD. At the RV site, APD continued to increase until 5 min of ischaemia and then shortened gradually. Consequently, dispersion of APD showed a rapid initial rise from 17.7 +/- 2.7 ms to 77.8 +/- 10.2 ms (P < 0.0001) followed by a slower final increase. TRT was uniform during normal perfusion (210.4 +/- 10.3, 213.1 +/- 7.8, 212.1 +/- 10.3 ms, ns) but became non-uniform during global ischaemia. The dispersion of TRT increased from 15.4 +/- 4.2 ms to 92.6 +/- 23.2 ms (P < 0.0001) during 14 min of global ischaemia. Both CT

  13. Protective effect of atrial natriuretic peptide on electrical-field-stimulated rat ventricular strips during hypoxia.

    PubMed

    Ljusegren, M E; Andersson, R G

    1994-12-01

    We have previously shown that atrial natriuretic peptide reduces lactate accumulation in non-beating rat ventricular myocardium exposed to hypoxic conditions, and that hypoxia induces release of atrial natriuretic peptide from isolated rat atrial tissue. In these studies we suggested that atrial natriuretic peptide may be physiologically important for protection of the myocardium during periods of oxygen deficit. In the present study, we used isolated strips of rat right ventricle, contracted by electrical-field-stimulation, as a model of a beating myocardium. After contraction stabilization, hypoxic conditions were introduced through aeration with 20% O2, held for 20 or 30 min., and then interrupted by reoxygenation with 95% O2. The contractile force was recorded and the percentage regain of the contractions after reoxygenation was considered as an indication of the amount of cell damage induced during the period of hypoxia. The results show that after 30 min. of hypoxia and subsequent reoxygenation, ventricular strips treated with atrial natriuretic peptide (0.1 microM) recovered 67.9 +/- 2.8% of the prehypoxic force of contraction; control strips from the same ventricle regained 44.9 +/- 4.4% (P = 0.015) of their initial contractile activity. After 20 min. of hypoxia followed by reoxygenation, a ventricular strip incubated together with an atrium regained 78.6 +/- 2.4% of the prehypoxic force of contraction as compared to a 60.2 +/- 2.7% regain (P = 0.002) for the control strip. We conclude that atrial natriuretic peptide protects the working ventricular myocardium during hypoxia, which further supports our previously reported suggestion that the effect on myocardial metabolism is physiologically relevant during situations of oxygen deficit in heart muscle. PMID:7899254

  14. Are isolated wetlands isolated?

    USGS Publications Warehouse

    Smith, Loren M.; Euliss, Ned H.; Haukos, David A.

    2011-01-01

    While federal regulations during the past 10 years have treated isolated wetlands as unconnected to aquatic resources protected by the Clean Water Act, they provide critical ecosystem services to society that extend well beyond their wetland boundaries. The authors offer well-documented examples from the scientific literature on some of the ecosystem services provided by isolated wetlands to society and other ecosystems.

  15. Morphometric analysis of cerebral ventricular system from MR images

    NASA Astrophysics Data System (ADS)

    Aziz, Aamer; Hu, QingMao; Nowinski, Wieslaw L.

    2004-04-01

    Cerebrospinal fluid filled ventricular system is an essential part of brain. The volume, shape and size of this ventricular system remain more or less constant and various pathologies directly or indirectly affect them. Morphometric analysis of cerebral ventricular system is important for evaluating changes due to growth, aging, intrinsic and extrinsic pathologies. Previous quantification efforts using ex vivo techniques suffered considerable error due to deformation of slices during sectioning, and numerous other factors. In vivo studies using air or contrast media also introduce volumetric changes in the ventricles thus giving erroneous quantitative information. Imaging of ventricular anatomy avoids these problems and allows repetitive studies following progression of ventricular system changes due to disease or natural processes. We have developed a methodology for automated extraction of ventricular system from MR neuroimages. Once extracted, landmarks are located on the surface of ventricular system automatically. These landmarks are then used for calculation of the ventricular shape, volume and size. A total of 20 brain ventricular systems were analyzed. The morphometric dimensions of the ventricles are presented in this paper. This study forms an initial basis for more advanced work on ventricular segmentation and morphometry.

  16. Electrocardiographic and morphometric features in patients with ventricular tachycardia of right ventricular origin

    PubMed Central

    Kazmierczak, J; De Sutter, J; Tavernier, R; Cuvelier, C; Dimmer, C; Jordaens, L

    1998-01-01

    Objective—To study differences between repetitive monomorphic ventricular tachycardia (RMVT) of right ventricular origin, and ventricular tachycardia in arrhythmogenic right ventricular dysplasia (ARVD).
Patients—Consecutive groups with RMVT (n = 15) or ARVD (n = 12), comparable for age and function.
Methods—Analysis of baseline, tachycardia, and signal averaged ECGs, clinical data, and right endomyocardial biopsies. Pathological findings were related to regional depolarisation (QRS width) and repolarisation (QT interval, QT dispersion).
Results—There was no difference in age, ejection fraction, QRS width in leads I, V1, and V6, and QT indices. During ventricular tachycardia, more patients with ARVD had a QS wave in V1 (p < 0.05). There were significant differences for unfiltered QRS, filtered QRS, low amplitude signal duration, and the root mean square voltage content. In the absence of bundle branch block, differences became non-significant for unfiltered and filtered QRS duration. Mean (SD) percentage of biopsy surface differed between RMVT and ARVD: normal myocytes (74(3.4)% v 64.5(9.3)%; p < 0.05); fibrosis (3(1.7)% v 8.9(5.2)%; p < 0.05). When all patients were included, there were significant correlations between fibrosis and age (r = 0.6761), and fibrosis and QRS width (r = 0.5524 for lead I; r = 0.5254 for lead V1; and r = 0.6017 for lead V6).
Conclusions—The ECG during tachycardia and signal averaging are helpful in discriminating between ARVD and RMVT patients. There are differences in the proportions of normal myocytes and fibrosis. The QRS duration is correlated with the amount of fibrous tissue in patients with ventricular tachycardia of right ventricular origin.

 Keywords: arrhythmogenic right ventricular dysplasia;  electrocardiography;  endomyocardial biopsy;  ventricular arrhythmias PMID:9616349

  17. Left Ventricular Dilatation Increases the Risk of Ventricular Arrhythmias in Patients With Reduced Systolic Function

    PubMed Central

    Aleong, Ryan G; Mulvahill, Matthew J; Halder, Indrani; Carlson, Nichole E; Singh, Madhurmeet; Bloom, Heather L; Dudley, Samuel C; Ellinor, Patrick T; Shalaby, Alaa; Weiss, Raul; Gutmann, Rebecca; Sauer, William H; Narayanan, Kumar; Chugh, Sumeet S; Saba, Samir; London, Barry

    2015-01-01

    Background Reduced left ventricular (LV) ejection fraction increases the risk of ventricular arrhythmias; however, LV ejection fraction has a low sensitivity to predict ventricular arrhythmias. LV dilatation and mass may be useful to further risk-stratify for ventricular arrhythmias. Methods and Results Patients from the Genetic Risk of Assessment of Defibrillator Events (GRADE) study (N =930), a study of heart failure subjects with defibrillators, were assessed for appropriate implantable cardioverter-defibrillator shock and death, heart transplant, or ventricular assist device placement by LV diameter and mass. LV mass was divided into normal, mild, moderate, and severe classifications. Severe LV end-diastolic diameter had worse shock-free survival than normal and mild LV end-diastolic diameter (P =0.0002 and 0.0063, respectively; 2-year shock free, severe 74%, moderate 80%, mild 91%, normal 88%; 4-year shock free, severe 62%, moderate 69%, mild 72%, normal 81%) and freedom from death, transplant, or ventricular assist device compared with normal and moderate LV end-diastolic diameter (P<0.0001 and 0.0441, respectively; 2-year survival: severe 78%, moderate 85%, mild 82%, normal 89%; 4-year survival: severe 55%, moderate 64%, mild 63%, normal 74%). Severe LV mass had worse shock-free survival than normal and mild LV mass (P =0.0370 and 0.0280, respectively; 2-year shock free: severe 80%, moderate 81%, mild 91%, normal 87%; 4-year shock free: severe 68%, moderate 73%, mild 76%, normal 76%) but no association with death, transplant, or ventricular assist device (P =0.1319). In a multivariable Cox proportional hazards analysis adjusted for LV ejection fraction, LV end-diastolic diameter was associated with appropriate implantable cardioverter-defibrillator shocks (hazard ratio 1.22, P =0.020). LV end-diastolic diameter was associated with time to death, transplant, or ventricular assist device (hazard ratio 1.29, P =0.0009). Conclusions LV dilatation may complement

  18. Right ventricular hydatid cyst ruptured to pericardium

    PubMed Central

    Sabzi, Feridoun; Vaziri, Siavoosh; Faraji, Reza

    2015-01-01

    Cardiac hydatidosis is rare presentation of body hydatidosis. Incidence of cardiac involvements range from 5% to 5% of patients with hydatid disease. Most common site of hydatid cyst in heart is interventricular septum and left ventricular free wall. Right ventricular free wall involvement by cyst that ruptured to pericardial cavity is very rare presentation of hydatid cyst. Cardiac involvement may have serious consequences such as rupture to blood steam or pericardial cavity. Both the disease and its surgical treatment carry a high complication rate, including rupture leading to cardiac tamponade, anaphylaxis and also death. In the present report, a 43-year-old man with constrictive pericarditis secondary to a pericardial hydatid cyst is described. PMID:26139761

  19. Echocardiographic assessment for ventricular assist device placement

    PubMed Central

    Essandoh, Michael; Yerington, Gregory C.; Bhatt, Amar M.; Iyer, Manoj H.; Perez, William; Davila, Victor R.; Tripathi, Ravi S.; Turner, Katja; Dimitrova, Galina; Andritsos, Michael J.

    2015-01-01

    While many factors depend on successful implantation and outcome of left ventricular assist devices (LVAD), echocardiography remains an integral part and is vital to the success of this process. Transesophageal echocardiography (TEE) allows interrogation of all the cardiac structures and great vessels. The pre-implantation TEE exam establishes a baseline and may identify potential problems that need palliation. Among these, most significant are aortic insufficiency (AI), intracardiac thrombi, poor right ventricular (RV) function, and intracardiac shunts. The post-implantation exam allows for adequate de-airing of the heart and successful LVAD initiation. The position and flow profiles of the inflow and outflow cannulas of the LVAD may be assessed. Finally, it assists in the astute management and vigilant identification and correction of a number of complications in the immediate post-implantation period. TEE will continue to remain vital to the successful outcomes LVAD patients. PMID:26793334

  20. Left ventricular heart failure and pulmonary hypertension†

    PubMed Central

    Rosenkranz, Stephan; Gibbs, J. Simon R.; Wachter, Rolf; De Marco, Teresa; Vonk-Noordegraaf, Anton; Vachiéry, Jean-Luc

    2016-01-01

    In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65–80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a ‘left ventricular phenotype’ to a ‘right ventricular phenotype’ across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context. PMID:26508169

  1. Salbutamol Abuse is Associated with Ventricular Fibrillation.

    PubMed

    Uysal, Emin; Solak, Suleyman; Carus, Murat; Uzun, Nedim; Cevik, Erdem

    2015-06-01

    Salbutamol-induced cardiac complications are well-established. Herein, we describe a case of a 24-year female who was admitted to the emergency department because of a suicide attempt with salbutamol (76 mg). Salbutamol abuse induced the development of supraventricular tachycardia and ventricular fibrillation. Regular sinus rhythm was restored with defibrillation. The hypokalemic patient who stayed in the intensive care unit was discharged after 48 hours of hospitalization. PMID:27336070

  2. [Ventricular preexcitation: is risk stratification feasible?].

    PubMed

    De Rosa, Francesco; Mancuso, Paola; Chiatto, Mario; Calvelli, Antonio; De Donato, Vincenzo; Mazza, Salvatore; Spadafora, Gabriele

    2010-04-01

    The Wolff-Parkinson-White syndrome is a current debated clinical issue. Although the anatomical characteristics, polymorphic electrocardiographic features, and electrophysiological mechanisms of arrhythmias and sudden cardiac death are well known, the identification of patients at risk of sudden cardiac death remains challenging. Owing to the lack of effective therapeutic strategies, in the pre-ablation era many studies have been conducted to define the prognostic value of clinical and instrumental tests, and to define the actual risk of sudden cardiac death in patients with ventricular preexcitation. Nowadays, radiofrequency transcatheter ablation of anomalous atrioventricular pathways is a strong therapeutic option for all patients, independent of the risk of sudden cardiac death. However, radiofrequency ablation is associated with serious complications, but many studies confirm an overall good prognosis for most of the patients with electrocardiographic pattern of ventricular preexcitation. The aim of this review is to assess the prognostic value of clinical and instrumental tests in patients with ventricular preexcitation, referring to the latest knowledge. PMID:20677574

  3. Management of arrhythmogenic right ventricular cardiomyopathy.

    PubMed

    Silvano, Maria; Mastella, Giulio; Zorzi, Alessandro; Migliore, Federico; Pilichou, Kalliopi; Bauce, Barbara; Rigato, Ilaria; Perazzolo Marra, Martina; Iliceto, Sabino; Thiene, Gaetano; Basso, Cristina; Corrado, Domenico

    2016-08-01

    Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically determined heart muscle disorder, predisposing to sudden cardiac death (SCD), particularly in young patients and athletes. Pathological features include loss of myocytes and fibrofatty replacement of right ventricular myocardium; a biventricular involvement is often observed. The diagnosis of ARVC (prevalence 1:5.000 in the general population) does not rely on a single gold standard test but is achieved using a scoring system, proposed in 2010 by an International Task Force, which encompasses familial and genetic factors, ECG abnormalities, arrhythmias, and structural/functional ventricular alterations. The main goal of treatment is the prevention of SCD. Implantable cardioverter defibrillator (ICD) is the only proven "lifesaving" therapy; however, it is associated with a significant morbidity due to device-related complications and inappropriate ICD interventions. Other treatment options such as life style changes, antiarrhythmic drugs, beta-blockers and catheter ablation may reduce the arrhythmic burden and alleviate symptoms, without evident impact on prevention of SCD. Selection of patient candidates to ICD implantation is the most challenging issue in the clinical management of ARVC. This article reviews the current perspective on management of ARVC, focusing on clinical manifestations, diagnostic criteria, risk stratification and therapeutic strategies of affected patients. PMID:27186923

  4. Left ventricular function in chronic renal failure.

    PubMed Central

    Lewis, B S; Milne, F J; Goldberg, B

    1976-01-01

    Left ventricular function was studied in 14 patients with end-stage chronic renal failure using non-invasive methods (echocardiography and systolic time intervals). Patients were divided into 3 groups. Group 1 consisted of 5 patients who were normotensive at the time of study and group 2 of 7 patients who were hypertensive when studied. Group 3 consisted of 2 patients: one was receiving propranolol and the other, studied 302 days after renal transplantation, was receiving digitalis for recurrent episodes of cardiac failure. All except the patient receiving propranolol had normal left ventricular function in systole with normal measurements of fractional fibre shortening (% delta S, EF) and normal measurements relating to the velocity of ventricular contraction (mean Vcf, mean velocity of posterior wall motion). Stroke volume and cardiac output were normal in some patients but were increased in patients with fluid overload. Early diastolic compliance of the left ventricle seemed to be normal except in the patient with recurrent cardiac failure. The study provided no evidence for the existence of a specific uraemic cardiomyopathy. PMID:1008967

  5. A new electric method for non-invasive continuous monitoring of stroke volume and ventricular volume-time curves

    PubMed Central

    2012-01-01

    Background In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP) is presented, that measures the average stroke volume (SV) for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition) with six independent electrode pairs distributed over the frontal thoracic skin. In contrast to existing non-invasive electric methods, our method does not use the algorithms of impedance or bioreactance cardiography. Instead, our method is based on specific 2D spatial patterns on the thoracic skin, representing the distribution, over the thorax, of changes in the applied current field caused by cardiac volume changes during the cardiac cycle. Since total heart volume variation during the cardiac cycle is a poor indicator for ventricular stroke volume, our HCP separates atrial filling effects from ventricular filling effects, and retrieves the volume changes of only the ventricles. Methods ex-vivo experiments on a post-mortem human heart have been performed to measure the effects of increasing the blood volume inside the ventricles in isolation, leaving the atrial volume invariant (which can not be done in-vivo). These effects have been measured as a specific 2D pattern of voltage changes on the thoracic skin. Furthermore, a working prototype of the HCP has been developed that uses these ex-vivo results in an algorithm to decompose voltage changes, that were measured in-vivo by the HCP on the thoracic skin of a human volunteer, into an atrial component and a ventricular component, in almost real-time (with a delay of maximally 39 seconds). The HCP prototype has been tested in-vivo on 7 human volunteers, using G-suit inflation and deflation to provoke stroke volume changes, and LVot Doppler as a reference technique. Results The ex-vivo measurements showed that ventricular filling caused a pattern over the

  6. Left ventricular performance indices by transesophageal Doppler.

    PubMed

    Thys, D M; Hillel, Z

    1988-11-01

    The purpose of this study was to assess whether blood flow velocity signals, obtained by esophageal continuous-wave Doppler, reflect changes in ventricular performance. Ventricular performance has previously been determined by analysis of blood flow velocity signals sampled in the ascending aorta. In this investigation velocity signals were acquired from the descending aorta, with the use of an esophageal Doppler transducer. Maximum blood flow velocity (Vm), maximum blood flow volume acceleration (Accv), and maximum linear blood flow acceleration (Acc) were the velocity signals used to evaluate left ventricular performance. Twenty-six patients scheduled for myocardial revascularization and anesthetized with fentanyl (50 micrograms/kg) and pancuronium (0.15 mg/kg) were studied. In seven patients (Group I) a good correlation (r = 0.91) was observed between Accv in the ascending and descending aorta. In 10 patients (Group 2), halothane (0.5 and 1.0 MAC end-tidal) was added to the anesthetic. At these halothane concentrations Vm, Accv, and Acc measured in the descending aorta remained unchanged. Decreases were noted in the product of mean arterial pressure (MAP) and Acc (P-Acc; decreased 20% at 0.5 MAC and 39% at 1 MAC) and the product of systemic vascular resistance and Acc (R-Acc; decreased 25% at 1 MAC). In nine patients (Group 3), phenylephrine was used to reverse the decrease in MAP induced by 1 MAC halothane. Under these conditions Vm, Accv, Acc, and P-Acc showed similar decreases (approximately 30% of baseline values), whereas R-Acc returned to baseline values. In summary, indices of blood flow in the descending aorta were easily determined with a commercial transesophageal continuous-wave Doppler device. Descending and ascending aortic blood flow Accv correlated well, and the changes in the product of MAP and Acc in the descending aorta reflected the anticipated, halothane-induced, changes in left ventricular performance. In conclusion, descending aortic blood

  7. Dealing with a left ventricular pseudoaneurysm during assist device implant.

    PubMed

    Ha, Richard V; Chiu, Peter; Banerjee, Dipanjan; Sheikh, Ahmad Y

    2016-06-01

    Despite increasing use of left ventricular devices for the surgical treatment of heart failure, there is limited experience with implantation of devices in the setting of challenging left apical anatomy. We report the case of a 68-year-old man with a chronic post-infarction calcified apical pseudoaneurysm, who underwent pseudoaneurysmectomy, ventricular myoplasty, and left ventricular assist device implantation. A review of the literature and operative strategies are presented. PMID:25834125

  8. Ventricular Tachycardia Following Surgical Repair of Complex Congenital Heart Disease.

    PubMed

    Baysa, Sherrie Joy; Kanter, Ronald J

    2016-03-01

    A nine year old boy with complex congenital heart disease requiring right ventricular outflow tract surgery and palpitations had inducible monomorphic ventricular tachycardia at 300 bpm by programmed ventricular stimulation. He was treated with enteral phenytoin. With a therapeutic plasma level, repeat electrophysiological study was negative for inducible ventricular tachycardia using an aggressive pacing protocol. An insertable loop recorder was implanted, and the family was prescribed an automatic external defibrillator. The decision to not place an implantable cardioverter-defibrillator was based upon anticipated need for serial cardiac MRI scans to monitor the effect of progressive outflow tract stenosis and regurgitation. PMID:26920195

  9. Left ventricular thrombus associated with arteriovenous extra corporeal membrane oxygenation

    PubMed Central

    Makdisi, George; Hashmi, Zubair A.; Wozniak, Thomas C.

    2015-01-01

    Extra corporeal membrane oxygenation (ECMO) has remarkably progressed over the recent years. It has become an invaluable tool in the care of adults and pediatric patients with severe cardiogenic shock. At the initiation of ECMO support, the left ventricular contractility is profoundly impaired. Inadequate right ventricular drainage and bronchial circulation can lead to left ventricular distension, with potential deleterious consequences, ranging from inadequate myocardial rest, pulmonary edema, or intracardiac clot formation. Therefore, it is of extreme importance to ensure an adequate left ventricular drainage. Here we present a case of LV thrombus developed while the patient is on central venoarterial (VA) ECMO. PMID:26716054

  10. Left ventricular thrombus associated with arteriovenous extra corporeal membrane oxygenation.

    PubMed

    Makdisi, George; Hashmi, Zubair A; Wozniak, Thomas C; Wang, I-Wen

    2015-11-01

    Extra corporeal membrane oxygenation (ECMO) has remarkably progressed over the recent years. It has become an invaluable tool in the care of adults and pediatric patients with severe cardiogenic shock. At the initiation of ECMO support, the left ventricular contractility is profoundly impaired. Inadequate right ventricular drainage and bronchial circulation can lead to left ventricular distension, with potential deleterious consequences, ranging from inadequate myocardial rest, pulmonary edema, or intracardiac clot formation. Therefore, it is of extreme importance to ensure an adequate left ventricular drainage. Here we present a case of LV thrombus developed while the patient is on central venoarterial (VA) ECMO. PMID:26716054

  11. Detection of Shockable Ventricular Arrhythmia using Variational Mode Decomposition.

    PubMed

    Tripathy, R K; Sharma, L N; Dandapat, S

    2016-04-01

    Ventricular tachycardia (VT) and ventricular fibrillation (VF) are shockable ventricular cardiac ailments. Detection of VT/VF is one of the important step in both automated external defibrillator (AED) and implantable cardioverter defibrillator (ICD) therapy. In this paper, we propose a new method for detection and classification of shockable ventricular arrhythmia (VT/VF) and non-shockable ventricular arrhythmia (normal sinus rhythm, ventricular bigeminy, ventricular ectopic beats, and ventricular escape rhythm) episodes from Electrocardiogram (ECG) signal. The variational mode decomposition (VMD) is used to decompose the ECG signal into number of modes or sub-signals. The energy, the renyi entropy and the permutation entropy of first three modes are evaluated and these values are used as diagnostic features. The mutual information based feature scoring is employed to select optimal set of diagnostic features. The performance of the diagnostic features is evaluated using random forest (RF) classifier. Experimental results reveal that, the feature subset derived from mutual information based scoring and the RF classifier produces accuracy, sensitivity and specificity values of 97.23 %, 96.54 %, and 97.97 %, respectively. The proposed method is compared with some of the existing techniques for detection of shockable ventricular arrhythmia episodes from ECG. PMID:26798076

  12. Hemolysis and Pulmonary Insufficiency following Right Ventricular Assist Device Implantation.

    PubMed

    Schubert, Sarah A; Soleimani, Behzad; Pae, Walter E

    2012-01-01

    We report a case of severe hemolysis and pulmonary valve insufficiency (PI) following right ventricular support using a paracorporeal pneumatic pump (Abiomed, Danvers, MA, USA). We speculate that the high velocity jet of blood emanating from the outflow cannula caused turbulence above the pulmonary valve, leading to PI and hemolysis. Despite the growing number of implanted ventricular assist devices, we could find no report in the literature describing pulmonary valve insufficiency secondary to right ventricular assist device (RVAD) placement. Fortunately, in this case, right ventricular function recovered sufficiently after seven days of support, allowing explantation of the device and resolution of PI and hemolysis. PMID:23213613

  13. Bi-ventricular circulatory support with the Abiomed AB5000 system in a patient with idiopathic refractory ventricular fibrillation.

    PubMed

    Zhang, Li; Kapetanakis, Emmanouil I; Cooke, Richard H; Sweet, Leslie C; Boyce, Steven W

    2007-01-01

    A 45-year-old man had life-threatening recurrent idiopathic ventricular fibrillation and persistent cardiogenic shock develop. The episodes of ventricular fibrillation were refractory to aggressive medical management; therefore an Abiomed AB5000 bi-ventricular support system was implanted for arrhythmia control. The device was able to maintain hemodynamic stability during the following 2 weeks. The patient was discharged from the hospital with fully recovered cardiac function. PMID:17184687

  14. Genetic manipulation of periostin expression reveals a role in cardiac hypertrophy and ventricular remodeling.

    PubMed

    Oka, Toru; Xu, Jian; Kaiser, Robert A; Melendez, Jaime; Hambleton, Michael; Sargent, Michelle A; Lorts, Angela; Brunskill, Eric W; Dorn, Gerald W; Conway, Simon J; Aronow, Bruce J; Robbins, Jeffrey; Molkentin, Jeffery D

    2007-08-01

    The cardiac extracellular matrix is a dynamic structural support network that is both influenced by, and a regulator of, pathological remodeling and hypertrophic growth. In response to pathologic insults, the adult heart reexpresses the secreted extracellular matrix protein periostin (Pn). Here we show that Pn is critically involved in regulating the cardiac hypertrophic response, interstitial fibrosis, and ventricular remodeling following long-term pressure overload stimulation and myocardial infarction. Mice lacking the gene encoding Pn (Postn) were more prone to ventricular rupture in the first 10 days after a myocardial infarction, but surviving mice showed less fibrosis and better ventricular performance. Pn(-/-) mice also showed less fibrosis and hypertrophy following long-term pressure overload, suggesting an intimate relationship between Pn and the regulation of cardiac remodeling. In contrast, inducible overexpression of Pn in the heart protected mice from rupture following myocardial infarction and induced spontaneous hypertrophy with aging. With respect to a mechanism underlying these alterations, Pn(-/-) hearts showed an altered molecular program in fibroblast function. Indeed, fibroblasts isolated from Pn(-/-) hearts were less effective in adherence to cardiac myocytes and were characterized by a dramatic alteration in global gene expression (7% of all genes). These are the first genetic data detailing the function of Pn in the adult heart as a regulator of cardiac remodeling and hypertrophy. PMID:17569887

  15. Latent Left Ventricular Outflow Tract Obstruction Due to Accessory Mitral Valve in a 12-Year-Old Boy

    PubMed Central

    Yun, Kyung Won; Park, Yong Hyun; Lee, Sang Hyun; Kim, Jeong Su; Kim, June Hong; Chun, Kook Jin

    2016-01-01

    Accessory mitral valve (AMV) is a rare congenital anomaly which can cause left ventricular outflow tract (LVOT) obstruction. Patients with isolated AMV usually present with exertional dyspnea, chest pain, or syncope during the first ten years of life. In patients with AMV, detection of latent LVOT obstruction can be clinically challenging. We here present a case of AMV causing latent LVOT obstruction in an adolescent, which was diagnosed by echocardiography with dobutamine provocation and finally treated by successful surgical resection. PMID:27471367

  16. B-Type Natriuretic Peptide Levels Predict Ventricular Arrhythmia Post Left Ventricular Assist Device Implantation.

    PubMed

    Hellman, Yaron; Malik, Adnan S; Lin, Hongbo; Shen, Changyu; Wang, I-Wen; Wozniak, Thomas C; Hashmi, Zubair A; Pickrell, Jeanette; Jani, Milena; Caccamo, Marco A; Gradus-Pizlo, Irmina; Hadi, Azam

    2015-12-01

    B-type natriuretic peptide (BNP) levels have been shown to predict ventricular arrhythmia (VA) and sudden death in patients with heart failure. We sought to determine whether BNP levels before left ventricular assist device (LVAD) implantation can predict VA post LVAD implantation in advanced heart failure patients. We conducted a retrospective study consisting of patients who underwent LVAD implantation in our institution during the period of May 2009-March 2013. The study was limited to patients receiving a HeartMate II or HeartWare LVAD. Acute myocardial infarction patients were excluded. We compared between the patients who developed VA within 15 days post LVAD implantation to the patients without VA. A total of 85 patients underwent LVAD implantation during the study period. Eleven patients were excluded (five acute MI, four without BNP measurements, and two discharged earlier than 13 days post LVAD implantation). The incidence of VA was 31%, with 91% ventricular tachycardia (VT) and 9% ventricular fibrillation. BNP remained the single most powerful predictor of VA even after adjustment for other borderline significant factors in a multivariate logistic regression model (P < 0.05). BNP levels are a strong predictor of VA post LVAD implantation, surpassing previously described risk factors such as age and VT in the past. PMID:25864448

  17. Catheter ablation for ventricular tachyarrhythmias in patients supported by continuous-flow left ventricular assist devices.

    PubMed

    Garan, Arthur R; Iyer, Vivek; Whang, William; Mody, Kanika P; Yuzefpolskaya, Melana; Colombo, Paolo C; Te-Frey, Rosie; Takayama, Hiroo; Naka, Yoshifumi; Garan, Hasan; Jorde, Ulrich P; Uriel, Nir

    2014-01-01

    Ventricular arrhythmias (VAs) are common after implantation of a left ventricular assist device (LVAD) and in a subset of patients may be refractory to medication. Morbidity from VA in this population includes right ventricular failure (RVF). We sought to evaluate the efficacy of catheter ablation for VA in patients with LVAD. A retrospective analysis of patients supported by continuous-flow LVAD referred for catheter ablation of ventricular tachycardia (VT) between 2008 and the present was performed. Seven patients were referred for VT ablation an average of 236 ± 292 days after LVAD implantation. Three patients (42.9%) developed RVF in the setting of intractable arrhythmias. A transfemoral approach was used for six patients (85.7%) and an epicardial for one patient (14.3%). The clinical VT was inducible and successfully ablated in six patients (85.7%). The location of these arrhythmias was apical in three cases (42.9%). A total of 13 VTs were ablated in seven patients. Although the majority had reduction in VA frequency, recurrent VAs were observed in six patients (85.7%). One patient (14.3%) experienced a bleeding complication after the procedure. For patients with a high VA burden after LVAD implantation, VT ablation is safe and feasible, but VA frequently recurs. PMID:24614361

  18. Hemodynamic effects of encainide in patients with ventricular arrhythmia and poor ventricular function

    SciTech Connect

    Sami, M.H.; Derbekyan, V.A.; Lisbona, R.

    1983-09-01

    Gated cardiac scanning was used to evaluate the hemodynamic effects of encainide in 19 patients (1 woman) with complex ventricular arrhythmia and depressed left ventricular (LV) function (ejection fraction less than 45%). Patients were 36 to 80 years old (average 61). All were candidates for long-term encainide therapy after having failed with currently available antiarrhythmics. Sixty-three percent had congestive heart failure before they received encainide. All were evaluated in the hospital before encainide therapy by a gated cardiac scan performed at least 3 days after discontinuing all antiarrhythmic drugs. Patients received oral encainide in doses of 75 to 200 mg. Gated cardiac scans were repeated 1 to 2 weeks later when an 80% reduction in frequency of premature ventricular complexes was observed on a 24-hour Holter recording. No patient had worsening of congestive heart failure during encainide therapy. Encainide did not significantly affect ejection fraction, which averaged 22 +/- 10% before and 25 +/- 14% (SD) after encainide (difference not significant (NS)). Other hemodynamic variables, including heart rate, blood pressure, stroke volume and end-diastolic volume, remained unchanged during encainide therapy. Digoxin blood levels in 10 patients averaged 1.04 +/- 0.43 before and 1.22 +/- 0.47 mg/ml (NS) during encainide therapy. Thus, encainide given orally in clinically effective doses does not appear to have significant hemodynamic effects in patients with ventricular arrhythmia and depressed LV function.

  19. Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium

    PubMed Central

    Myles, Rachel C.; Bernus, Olivier; Burton, Francis L.; Cobbe, Stuart M.

    2010-01-01

    Although transmural heterogeneity of action potential duration (APD) is established in single cells isolated from different tissue layers, the extent to which it produces transmural gradients of repolarization in electrotonically coupled ventricular myocardium remains controversial. The purpose of this study was to examine the relative contribution of intrinsic cellular gradients of APD and electrotonic influences to transmural repolarization in rabbit ventricular myocardium. Transmural optical mapping was performed in left ventricular wedge preparations from eight rabbits. Transmural patterns of activation, repolarization, and APD were recorded during endocardial and epicardial stimulation. Experimental results were compared with modeled data during variations in electrotonic coupling. A transmural gradient of APD was evident during endocardial stimulation, which reflected differences previously seen in isolated cells, with the longest APD at the endocardium and the shortest at the epicardium (endo: 165 ± 5 vs. epi: 147 ± 4 ms; P < 0.05). During epicardial stimulation, this gradient reversed (epi: 162 ± 4 vs. endo: 148 ± 6 ms; P < 0.05). In both activation sequences, transmural repolarization followed activation and APD shortened along the activation path such that significant transmural gradients of repolarization did not occur. This correlation between transmural activation time and APD was recapitulated in simulations and varied with changes in intercellular coupling, confirming that it is mediated by electrotonic current flow between cells. These data suggest that electrotonic influences are important in determining the transmural repolarization sequence in rabbit ventricular myocardium and that they are sufficient to overcome intrinsic differences in the electrophysiological properties of the cells across the ventricular wall. PMID:20889843

  20. [Recurrent failed ICD therapy of ventricular tachycardia].

    PubMed

    Hein, W; Ellringmann, U; Vollmann, D; Rostock, T; Schott, P

    2012-11-01

    Implantable cardioverter defibrillators (ICD) are used as standard therapy to prevent sudden cardiac death in heart failure patients. Today, physicians in emergency and intensive care medicine are often confronted with problems of ICD therapy in these patients. We report a case of a patient suffering from recurrent ventricular tachycardia (VT) requiring antiarrhythmia treatment with amiodarone. With an increasing drug loading, the VT cycle length was progressively prolonged resulting in a slow VT undetectable for the ICD. Subsequently, the patient was scheduled for VT ablation after which the patient became free of arrhythmia recurrences. PMID:23070331

  1. Ventricular shunt infections: Immunopathogenesis and clinical management

    PubMed Central

    Gutierrez-Murgas, Yenis; Snowden, Jessica N.

    2014-01-01

    Ventricular shunts are the most common neurosurgical procedure performed in the United States. This hydrocephalus treatment is often complicated by infection of the device with biofilm-forming bacteria. In this review, we discuss the pathogenesis of shunt infection, as well as the implications of the biofilm formation on treatment and prevention of these infections. Many questions remain, including the contribution of glia and the impact of inflammation on developmental outcomes following infection. Immune responses within the CNS must be carefully regulated to contain infection while minimizing bystander damage; further study is needed to design optimal treatment strategies for these patients. PMID:25156073

  2. The future of left ventricular assist devices

    PubMed Central

    2015-01-01

    The widespread acceptance of left ventricular assist device (LVAD) implantation in the treatment of heart failure has revolutionized the way end stage heart failure is treated. Advances in LVAD technology combined with a better understanding of patient selection has led to unparalleled survival as well as a reduction in the adverse event profile of these pumps. As our understanding of heart failure continues to grow, there is little doubt that LVADs will continue to play a pivotal role as a therapeutic option for those suffering from heart failure. PMID:26793340

  3. Loeffler endocarditis: silent right ventricular myocardium!

    PubMed

    Çetin, Süha; Heper, Gülümser; Gökhan Vural, Mustafa; Hazirolan, Tuncay

    2016-07-01

    We present the case of a 54-year-old male patient with Loeffler endocarditis. It is a rare disorder characterized by fibrous thickening of the endocardium leading to apical obliteration and restrictive cardiomyopathy resulting in heart failure, thromboembolic events or atrial fibrillation. To the best of our knowledge, this is the first case reporting the electrical silence of the right ventricular (RV) apex caused by fibrothrombotic thickening of this area. Under these circumstances RV apical implantation of an implantable cardioverter defibrillator (ICD) or pacemaker electrode may lead to unsuccessful stimulation of these devices. PMID:26980214

  4. Current-Voltage Relationship for Late Na(+) Current in Adult Rat Ventricular Myocytes.

    PubMed

    Clark, R B; Giles, W R

    2016-01-01

    It is now well established that the slowly inactivating component of the Na(+) current (INa-L) in the mammalian heart is a significant regulator of the action potential waveform. This insight has led to detailed studies of the role of INa-L in a number of important and challenging pathophysiological settings. These include genetically based ventricular arrhythmias (LQT 1, 2, and 3), ventricular arrhythmias arising from progressive cardiomyopathies (including diabetic), and proarrhythmic abnormalities that develop during local or global ventricular ischemia. Inhibition of INa-L may also be a useful strategy for management of atrial flutter and fibrillation. Many important biophysical parameters that characterize INa-L have been identified; and INa-L as an antiarrhythmia drug target has been studied extensively. However, relatively little information is available regarding (1) the ion transfer or current-voltage relationship for INa-L or (2) the time course of its reactivation at membrane potentials similar to the resting or diastolic membrane potential in mammalian ventricle. This chapter is based on our preliminary findings concerning these two very important physiological/biophysical descriptors for INa-L. Our results were obtained using whole-cell voltage clamp methods applied to enzymatically isolated rat ventricular myocytes. A chemical agent, BDF 9148, which was once considered to be a drug candidate in the Na(+)-dependent inotropic agent category has been used to markedly enhance INa-L current. BDF acts in a potent, selective, and reversible fashion. These BDF 9148 effects are compared and contrasted with the prototypical activator of INa-L, a sea anemone toxin, ATX II. PMID:27586292

  5. A Randomized Controlled Trial:Treatments on Infundibular Ventricular Septal Defect

    ClinicalTrials.gov

    2015-02-06

    Heart Septal Defects, Ventricular; Double Outlet Right Ventricle, Noncommitted VSD; Double Outlet Right Ventricle, Subaortic VSD; Double Outlet Right Ventricle, Subpulmonary VSD; Supracristal Ventricular Septal Defect

  6. The role of intraventricular vortices in the left ventricular filling?

    NASA Astrophysics Data System (ADS)

    Martinez-Legazpi, Pablo; Bermejo, Javier; Benito, Yolanda; Alhama, Marta; Yotti, Raquel; Perez Del Villar, Candelas; Gonzalez-Mansilla, Ana; Barrio, Alicia; Fernandez-Aviles, Francisco; Del Alamo, Juan Carlos

    2013-11-01

    The generation of vortices during early filling is a salient feature of left ventricular hemodynamics. Existing clinical data suggest that these intraventricular vortices may facilitate pulling flow from the left atrium. To test this hypothesis, we have quantitatively dissected the contribution of the vortex to intraventricular pressure gradients by isolating its induced flow in ultrasound-derived data in 20 patients with non-ischemic dilated cardiomyopathy (NIDCM), 20 age-matched healthy controls and 20 patients with hypertrophied cardiomyopathy. We have observed that, in patients with NIDCM, the hemodynamic forces were shown to be partially supported by the flow inertia whereas that effect was minimized in healthy hearts. In patients with hypertrophied cardiomiopathy such effect was not observed. Supported by grants, PIS09/02603, RD06/0010 (RECAVA), CM12/00273 (to CPV) and BA11/00067 (to JB) from the Instituto de Salud Carlos III, Spain. PML and JCA were partially supported by NIH grant 1R21 HL108268-01.

  7. Echocardiographic assessment of ejection fraction in left ventricular hypertrophy

    PubMed Central

    Wandt, B; Bojo, L; Tolagen, K; Wranne, B

    1999-01-01

    OBJECTIVE—To investigate the value of Simpson's rule, Teichholz's formula, and recording of mitral ring motion in assessing left ventricular ejection fraction (EF) in patients with left ventricular hypertrophy.
DESIGN—Left ventricular ejection fraction calculated by Simpson's rule and by Techholz's formula and estimated by mitral ring motion was compared with values obtained by radionuclide angiography.
SETTING—Secondary referral centre.
PATIENTS—16 patients with left ventricular hypertrophy and a clinical diagnosis of hypertrophic cardiomyopathy or hypertension.
RESULTS—Calculation by Teichholz's formula overestimated left ventricular ejection fraction by 10% (p = 0.002) and estimation based on mitral ring motion—that is, long axis measurements—underestimated ejection fraction by 19% (p = 0.002), without significant correlation between ring motion and ejection fraction. There was no significant difference between mean values of ejection fraction calculated by Simpson's rule and measured by the reference method, but a considerable scatter about the regression line with a standard error of the estimate of 9.3 EF%.
CONCLUSIONS—In patients with left ventricular hypertrophy the ejection fraction, calculated by Teichholz's formula or Simpson's rule, is a poor measure of left ventricular function. When mitral ring motion is used for the assessment in these patients the function should be expressed in ways other than by the ejection fraction.


Keywords: left ventricular hypertrophy; ejection fraction; mitral ring motion; atrioventricular plane displacement PMID:10409535

  8. Right ventricular dysfunction in patients with septic shock.

    PubMed

    Dhainaut, J F; Lanore, J J; de Gournay, J M; Huyghebaert, M F; Brunet, F; Villemant, D; Monsallier, J F

    1988-01-01

    Using a rapid computerized thermodilution method, we examined the evolution of right ventricular performance in 23 patients with septic shock. Nine survived the episode of septic shock. The other 14 patients died of refractory circulatory shock. Significant right ventricular systolic dysfunction, defined as decreased ejection fraction (-39%) and right ventricular dilation (+38%) was observed in all patients with septic shock. However, in the survivors, increased right ventricular preload may prevent hemodynamic evidence of right ventricular pump failure by utilizing the Frank-Starling mechanism to maintain stroke volume. Conversely, in the nonsurvivors, right ventricular dysfunction was more prononced two days after the onset of septic shock, leading to a fall in stroke. In the last patients, a decrease in contractility appears to be the major factor accounting for decreased right ventricular performance, as evidenced by the marked increase in end-systolic volume (+27%) without significant change in pulmonary artery pressure, during the later stage of septic shock. The observed right ventricular pump failure then appears associated with an alteration in diastolic mechanical properties of this ventricle, as suggested by a leftward displacement of the individual pressure-volume curves. PMID:3403793

  9. Direct recording of concealed ventricular extrasystoles producing pacer inhibition.

    PubMed

    Bowers, Mark; Berger, Marcie

    2013-10-01

    We report a case of concealed extrasystoles recorded from a pacing lead. The concealed extrasystoles were observed with right ventricular pacing, biventricular unipolar, and biventricular bipolar pacing. The simultaneous surface EKG did not show manifest ventricular extrasystoles with the concealed intracardiac potentials. This case highlights a cause of oversensing that has been theoretically reported in the literature but never directly observed. PMID:23600888

  10. Aortic coarctation, aneurysm, and ventricular dysfunction in an asymptomatic infant.

    PubMed

    García, Ana I; Aguilar, Juan M; García, Enrique

    2016-06-01

    Aortic arch coarctation with post-coarctation aneurysm is rare in infants. We present the case of an asymptomatic 3-month-old infant with severe left ventricular dysfunction in this setting. The patient underwent surgical repair, and the left ventricular ejection fraction improved to recovery the 4th post-operative month. PMID:26980403

  11. Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy

    PubMed Central

    Lanjewar, Swapnil S; Chhabra, Lovely; Chaubey, Vinod K; Joshi, Saurabh; Kulkarni, Ganesh; Kothagundla, Chandrasekhar; Kaul, Sudesh; Spodick, David H

    2013-01-01

    Background The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration. Methods We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1) were computed and compared between the two subgroups. Results There was no statistically significant difference in qualitative lung function (FEV1) between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy. Conclusion The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration. PMID:24293995

  12. Detection of left ventricular aneurysm on two dimensional echocardiography.

    PubMed

    Baur, H R; Daniel, J A; Nelson, R R

    1982-07-01

    The differentiation of left ventricular aneurysm from diffuse left ventricular dilation and hypokinesia may have important therapeutic consequences. Thus the diagnostic accuracy of wide angle two dimensional echocardiography for the detection of left ventricular aneurysm was evaluated in a prospective study of 26 consecutive patients with the clinical suspicion of left ventricular aneurysm referred over a 10 month period. Every patients was examined with two dimensional echocardiography and left ventricular cineangiography, and findings were interpreted by two independent observers. A dilated hypokinetic left ventricle without aneurysm formation on cineangiography in nine patients was identified in all with two dimensional echocardiography. A left ventricular aneurysm on cineangiography in 17 patients was correctly identified in 14 with the two dimensional study, as were the site and extent of the lesion (apical in 12, anterior in 1 and inferior in 1). One apical aneurysm was interpreted on the two dimensional study as apical dyskinesia; one anterior and one posterobasal aneurysm were missed with this technique. Mural thrombi were correctly identified with two dimensional echocardiography in seven of seven patients. It is concluded that two dimensional echocardiography is an accurate noninvasive method that allows differentiation of left ventricular aneurysm from diffuse left ventricular dilation in the majority of patients. It provides information regarding the resectability of the aneurysm and may obviate cineangiography in many cases. PMID:7091001

  13. A Case Report of Renal Sympathetic Denervation for the Treatment of Polymorphic Ventricular Premature Complexes: Expanding Horizons.

    PubMed

    Kiuchi, Márcio Galindo; Vitorio, Frederico Puppim; da Silva, Gustavo Ramalho; Paz, Luis Marcelo Rodrigues; Souto, Gladyston Luiz Lima

    2015-12-01

    Premature ventricular complexes are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Recently, Armaganijan et al reported the relevance of sympathetic activation in patients with ventricular arrhythmias and suggested a potential role for catheter-based renal sympathetic denervation in reducing the arrhythmic burden. In this report, we describe a 32-year-old hypertensive male patient presenting with a high incidence of polymorphic premature ventricular complexes on a 24  hour Holter monitor. Beginning 1 year prior, the patient experienced episodes of presyncope, syncope, and tachycardia palpitations. The patient was taking losartan 100  mg/day, which kept his blood pressure (BP) under control, and sotalol 160  mg twice daily. Bisoprolol 10  mg/day was used previously but was not successful for controlling the episodes. The 24  hour Holter performed after the onset of sotalol 160  mg twice daily showed a heart rate ranging between 48 (minimum)-78 (average)-119 (maximum) bpm; 14,286 polymorphic premature ventricular complexes; 3 episodes of nonsustained ventricular tachycardia, the largest composed of 4 beats at a rate of 197 bpm; and 14 isolated atrial ectopic beats. Cardiac magnetic resonance imaging with gadolinium perfusion performed at rest and under pharmacological stress with dipyridamole showed increased left atrial internal volume, preserved systolic global biventricular function, and an absence of infarcted or ischemic areas. The patient underwent bilateral renal sympathetic denervation. The only drug used postprocedure was losartan 25  mg/day. Three months after the patient underwent renal sympathetic denervation, the mean BP value dropped to 132/86  mmHg, the mean systolic/diastolic 24  hour ambulatory BP measurement was reduced to 128/83

  14. Ventricular fiber optimization utilizing the branching structure.

    PubMed

    Washio, Takumi; Yoneda, Kazunori; Okada, Jun-Ichi; Kariya, Taro; Sugiura, Seiryo; Hisada, Toshiaki

    2016-07-01

    In this paper, we propose an algorithm that optimizes the ventricular fiber structure of the human heart. A number of histological studies and diffusion tensor magnetic resonance imaging analyses have revealed that the myocardial fiber forms a right-handed helix at the endocardium. However, the fiber formation changes its orientation as a function of transmural depth, becoming a left-handed helix at the epicardium. To determine how nature can construct such a structure, which obtains surprising pumping performance, we introduce macroscopic modeling of the branching structure of cardiac myocytes in our finite element ventricular model and utilize this in an optimization process. We put a set of multidirectional fibers around a central fiber orientation at each point of the ventricle walls and simulate heartbeats by generating contraction forces along each of these directions. We examine two optimization processes using the workloads or impulses measured in these directions to update the central fiber orientation. Both processes improve the pumping performance towards an optimal value within several tens of heartbeats, starting from an almost-flat fiber orientation. However, compared with the workload optimization, the impulse optimization produces better agreement with experimental studies on transmural changes of fiber helix angle, streamline patterns of characteristic helical structures, and temporal changes in strain. Furthermore, the impulse optimization is robust under geometrical changes of the heart and tends to homogenize various mechanical factors such as the stretch and stretch rate along the fiber orientation, the contraction force, and energy consumption. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26453026

  15. Left ventricular assist using a jet pump.

    PubMed

    Rhee, K; Blackshear, P L

    1990-01-01

    A simple, effective, cardiac assist device was developed using a jet pump, a device that performs pumping by energy transfer from a high speed jet to low speed surrounding fluids. This jet pump is inserted retrograde through the aorta and placed in the left ventricle transvalvularly. The jet of oxygenated venous blood entrains blood inside the left ventricle and pumps into the aorta through the aortic valve. Jet velocity is kept below the hemolytic threshold of 1000 cm/sec. The device was placed in a mock circulatory system that stimulates the left ventricle and vascular system by generating a pressure wave (120/75 mmHg) with a 4 L/min cardiac output (CO). A bypass loop (from the venous reservoir to aorta using a Biomedicus pump, Biomedicus Inc., Eden Prairie, MN) was set up, and the jet pump was installed. When the jet pump is turned on, bypass flow rate (BF) is 2.5 L/min, entrainment pumping 1.5 L/min, and peak ventricular pressure (VP) falls below aortic pressure (AP), while maintaining the mean AP. Time tension index (TTI) is decreased 31%. This result, when compared with simple bypass at differing BF, shows more than a 20% reduction in TTI. This simple jet pump provided significant unloading of the left ventricle and may be potentially useful as a left ventricular assist device. PMID:2252738

  16. Phase statistics approach to human ventricular fibrillation

    NASA Astrophysics Data System (ADS)

    Wu, Ming-Chya; Watanabe, Eiichi; Struzik, Zbigniew R.; Hu, Chin-Kun; Yamamoto, Yoshiharu

    2009-11-01

    Ventricular fibrillation (VF) is known to be the most dangerous cardiac arrhythmia, frequently leading to sudden cardiac death (SCD). During VF, cardiac output drops to nil and, unless the fibrillation is promptly halted, death usually ensues within minutes. While delivering life saving electrical shocks is a method of preventing SCD, it has been recognized that some, though not many, VF episodes are self-terminating, and understanding the mechanism of spontaneous defibrillation might provide newer therapeutic options for treatment of this otherwise fatal arrhythmia. Using the phase statistics approach, recently developed to study financial and physiological time series, here, we reveal the timing characteristics of transient features of ventricular tachyarrhythmia (mostly VF) electrocardiogram (ECG) and find that there are three distinct types of probability density function (PDF) of phase distributions: uniform (UF), concave (CC), and convex (CV). Our data show that VF patients with UF or CC types of PDF have approximately the same probability of survival and nonsurvival, while VF patients with CV type PDF have zero probability of survival, implying that their VF episodes are never self-terminating. Our results suggest that detailed phase statistics of human ECG data may be a key to understanding the mechanism of spontaneous defibrillation of fatal VF.

  17. Prolonged Ventricular Asystole: A Rare Adverse Effect of Hydrocodone Use

    PubMed Central

    Sudhakaran, Sivakumar; Surani, Saherish S.; Surani, Salim R.

    2014-01-01

    Patient: Female, 56 Final Diagnosis: Ventricular asystole Symptoms: Dizziness, headache, near-syncope, weakness Medication: — Clinical Procedure: — Specialty: Cardiology Objective: Unusual clinical course Background: Prolonged ventricular asystole is a rare vagal reaction caused by hydrocodone use. Sinus bradycardia is a characteristic presentation of the vasovagal response; examples of other presentations include arrest or atrioventricular block. Physicians need to be aware of ventricular asystole due to vagally-mediated atrioventricular block caused by hydrocodone or other opiates. Case Report: We present a case of prolonged ventricular asystole in a young patient due to a vasovagal reaction caused by the hydrocodone found in the hydrocodone/acetaminophen combination. Conclusions: Ventricular asystole can be a rare complication of hydrocodone found in hydrocodone/acetaminophen. Physicians need to be aware of this adverse effect, rather then resorting to expensive diagnostic interventions. PMID:25330933

  18. Left Ventricular Assist Device Implantation After Intracardiac Parachute Device Removal.

    PubMed

    Abu Saleh, Walid K; Al Jabbari, Odeaa; Bruckner, Brian A; Suarez, Erik E; Estep, Jerry D; Loebe, Matthias

    2015-08-01

    Left ventricular assist device implantation is a proven and efficient modality for the treatment of end-stage heart failure. Left ventricular assist device versatility as a bridge to heart transplantation or destination therapy has led to improved patient outcomes with a concomitant rise in its overall use. Other less invasive treatment modalities are being developed to improve heart function and morbidity and mortality for the heart failure population. Percutaneous ventricular restoration is a new investigational therapy that deploys an intracardiac parachute to wall off damaged myocardium in patients with dilated left ventricles and ischemic heart failure. Clinical trials are under way to test the efficacy of percutaneous ventricular restoration using the parachute device. This review describes our encounter with the parachute device, its explantation due to refractory heart failure, and surgical replacement with a left ventricular assist device. PMID:26234850

  19. Logistic time constant of isometric relaxation force curve of ferret ventricular papillary muscle: reliable index of lusitropism.

    PubMed

    Mizuno, J; Araki, J; Mikane, T; Mohri, S; Imaoka, T; Matsubara, H; Okuyama, H; Kurihara, S; Ohe, T; Hirakawa, M; Suga, H

    2000-10-01

    We have found that a logistic function fits the left ventricular isovolumic relaxation pressure curve in the canine excised, cross-circulated heart more precisely than a monoexponential function. On this basis, we have proposed a logistic time constant (tau(L)) as a better index of ventricular isovolumic lusitropism than the conventional monoexponential time constant (tau(E)). We hypothesize in the present study that this tau(L) would also be a better index of myocardial isometric lusitropism than the conventional tau(E). We tested this hypothesis by analyzing the isometric relaxation force curve of 114 twitches of eight ferret isolated right ventricular papillary muscles. The muscle length was changed between 82 and 100% L(max) and extracellular Ca(2+) concentrations ([Ca(2+)](o)) between 0.2 and 8 mmol/l. We found that the logistic function always fitted the isometric relaxation force curve much more precisely than the monoexponential function at any muscle length and [Ca(2+)](o) level. We also found that tau(L) was independent of the choice of the end of isometric relaxation but tau(E) was considerably dependent on it as in ventricular relaxation. These results validated our present hypothesis. We conclude that tau(L) is a more reliable, though still empirical, index of lusitropism than conventional tau(E) in the myocardium as in the ventricle. PMID:11120914

  20. [Relationship between left ventricular mass and prognosis of arterial hypertension].

    PubMed

    Devereux, R B

    1990-12-01

    Echocardiographic measurement of left ventricular mass has provided a way of evaluating the undesirable effects of high blood pressure on the heart in the same way as for obesity, excess salt intake and blood hyperviscosity. Recently, the left ventricular mass was shown to correlate (r = 0.81) with the hemodynamic stimuli of blood pressure, stroke volume and left ventricular contractility. Prospective trials at Cornell and Framingham indicate that left ventricular mass is a powerful predictive factor of the risk of complications in hypertension. In the first of these trials, we demonstrated in a 5 year follow-up study of 140 men with uncomplicated hypertension that the incidence of death, myocardial infarction or angina requiring myocardial revascularisation, was four times greater in patients with increased left ventricular mass and that this association was independent of the blood pressure levels. Then, in a 10 year follow-up study of hypertensive patients of both sexes, we established that the left ventricular mass was the most powerful predictive factor of mortality and morbidity and that this was so marked (15% death rate in subjects with LVH vs 1% in subjects with normal left ventricular mass--p less than 0.00001--, cardiovascular accidents in 26% of subjects with LVH compared with 12% in subjects with normal left ventricular mass--p less than 0.0001) that only left ventricular mass and age were independant predictive factors of morbid events in multiple variable analysis. In the Framingham study, the frequency of coronary events in a 4 year follow-up period of healthy subjects from the original cohort (average age 69 years) was significantly related to the left ventricular mass and independent of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2080892

  1. Comparative electrophysiological effects of captopril or hydralazine combined with nitrate in patients with left ventricular dysfunction and inducible ventricular tachycardia.

    PubMed Central

    Bashir, Y; Sneddon, J F; O'Nunain, S; Paul, V E; Gibson, S; Ward, D E; Camm, A J

    1992-01-01

    OBJECTIVE--To assess the electrophysiological and antiarrhythmic effects of pharmacological load manipulation by an angiotensin converting enzyme (ACE) inhibitor (captopril) and a direct vasodilator (hydralazine plus isosorbide mononitrate) in patients with inducible ventricular tachycardia and impaired left ventricular function. DESIGN--Randomised open label cross-over comparison of three regimens. SETTING--Tertiary arrhythmia referral centre. SUBJECTS--Eight patients with reduced left ventricular function and sustained ventricular tachycardia inducible by programmed stimulation. INTERVENTIONS--Three treatment regimens each of 48 hours duration: captopril, hydralazine plus isosorbide mononitrate, and control (no vasodilator). MAIN OUTCOME MEASURES--Changes in central haemodynamics, electrophysiological parameters, and induction of ventricular tachycardia during treatment with captopril, or hydralazine combined with nitrate, compared with a control period. RESULTS--Both vasodilator treatments produced similar balanced reductions in peak systolic pressures and filling pressures compared with controls. Captopril had no effect on sinus cycle length, atrial refractoriness, or intraventricular conduction, but prolonged ventricular effective and functional refractory periods and QT interval during constant rate atrial pacing. Hydralazine combined with nitrate did not significantly alter any electrophysiological variable. Ventricular tachycardia was similarly inducible during all three periods. CONCLUSIONS--Load manipulation by captopril but not hydralazine combined with nitrate prolonged ventricular refractoriness and repolarisation, possibly reflecting a combination of mechano-electrical effect with the restraining influence of ACE inhibitors on reflex sympathetic stimulation. PMID:1389714

  2. Effects of chronic beta-adrenergic blockade on the left ventricular and cardiocyte abnormalities of chronic canine mitral regurgitation.

    PubMed Central

    Tsutsui, H; Spinale, F G; Nagatsu, M; Schmid, P G; Ishihara, K; DeFreyte, G; Cooper, G; Carabello, B A

    1994-01-01

    The mechanism by which beta blockade improves left ventricular dysfunction in various cardiomyopathies has been ascribed to improved contractile function of the myocardium or to improved beta-adrenergic responsiveness. In this study we tested two hypotheses: (a) that chronic beta blockade would improve the left ventricular dysfunction which develops in mitral regurgitation, and (b) that an important mechanism of this effect would be improved innate contractile function of the myocardium. Two groups of six dogs with chronic severe mitral regurgitation were studied. After 3 mo both groups had developed similar and significant left ventricular dysfunction. One group was then gradually beta-blocked while the second group continued to be observed without further intervention. In the group that remained unblocked, contractile function remained depressed. However, in the group that received chronic beta blockade, contractile function improved substantially. The contractility of cardiocytes isolated from the unblocked hearts and then studied in the absence of beta receptor stimulation was extremely depressed. However, contractility of cardiocytes isolated from the beta-blocked ventricles was virtually normal. Consistent with these data, myofibrillar density was much higher, 55 +/- 4% in the beta-blocked group vs. 39 +/- 2% (P < 0.01) in the unblocked group; thus, there were more contractile elements to generate force in the beta-blocked group. We conclude that chronic beta blockade improves left ventricular function in chronic experimental mitral regurgitation. This improvement was associated with an improvement in the innate contractile function of isolated cardiocytes, which in turn is associated with an increase in the number of contractile elements. Images PMID:7911128

  3. Relationship of ventricular arrhythmias to the angiographically and scintigraphically estimated extent of ventricular damage late after myocardial infarction

    SciTech Connect

    Huikuri, H.V.; Korhonen, U.R.; Linnaluoto, M.K.; Takkunen, J.T.

    1987-03-01

    In order to study the quantitative relationship of ventricular arrhythmias to myocardial damage and ischemia, 61 patients with a previous myocardial infarction (at least 6 months previously) were studied by 24-hour ambulatory ECG monitoring, cardiac catheterization, and thallium-201 scintigraphy. Thirty-five patients (57%) had no ectopic beats or only infrequent, unifocal ones and 26 patients (43%) had complex ventricular arrhythmias. Left ventricular function was lower in the latter, but the number of diseased vessels did not differ in the two groups. The reduction of thallium activity in the infarct area was more marked in patients with complex arrhythmias. Multiple thallium defects were not more common in arrhythmia patients, however. These data support the view that complex ventricular arrhythmias are more closely related to the severity of ventricular damage than the presence of myocardial ischemia remote to the area of previous infarction.

  4. Witten index for noncompact dynamics

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Joo; Yi, Piljin

    2016-06-01

    Among gauged dynamics motivated by string theory, we find many with gapless asymptotic directions. Although the natural boundary condition for ground states is L 2, one often turns on chemical potentials or supersymmetric mass terms to regulate the infrared issues, instead, and computes the twisted partition function. We point out how this procedure generically fails to capture physical L 2 Witten index with often misleading results. We also explore how, nevertheless, the Witten index is sometimes intricately embedded in such twisted partition functions. For d = 1 theories with gapless continuum sector from gauge multiplets, such as non-primitive quivers and pure Yang-Mills, a further subtlety exists, leading to fractional expressions. Quite unexpectedly, however, the integral L 2 Witten index can be extracted directly and easily from the twisted partition function of such theories. This phenomenon is tied to the notion of the rational invariant that appears naturally in the wall-crossing formulae, and offers a general mechanism of reading off Witten index directly from the twisted partition function. Along the way, we correct early numerical results for some of mathcal{N} = 4 , 8 , 16 pure Yang-Mills quantum mechanics, and count threshold bound states for general gauge groups beyond SU( N ).

  5. The Burden of Ventricular Arrhythmias Following Left Ventricular Assist Device Implantation

    PubMed Central

    Griffin, Jan M

    2014-01-01

    Few innovations in medicine have so convincingly and expeditiously improved patient outcomes more than the development of the left ventricular assist device (LVAD). Where optimal pharmacotherapy once routinely failed those with end-stage disease, the LVAD now offers considerable hope for the growing advanced heart failure population. Despite improvements in mortality, however, mechanical circulatory support is not without its limitations. Those supported with an LVAD are at increased risk of several complications, including infection, bleeding, stroke and arrhythmic events. While once considered benign, ventricular arrhythmias in the LVAD patient are being increasingly recognised for their deleterious influence on patient morbidity and quality of life. In addition, the often multifactorial aetiology to these episodes makes treatment difficult and optimal therapeutic management controversial. Novel strategies are clearly needed to better predict, prevent, and eradicate these arrhythmias in order to allow future generations of heart failure patients to reap the full benefits of LVAD implantation. PMID:26835082

  6. Right Ventricular Dysfunction During Intensive Pharmacologic Unloading Persists After Mechanical Unloading

    PubMed Central

    Palardy, Maryse; Nohria, Anju; Rivero, Jose; Lakdawala, Neal; Campbell, Patricia; Kato, Mahoto; Griffin, Leslie M.; Smith, Colleen M.; Couper, Gregory S.; Stevenson, Lynne W.; Givertz, Michael M.

    2014-01-01

    Background Right ventricular (RV) dysfunction is associated with adverse outcomes in heart failure (HF). Mechanical unloading should be more effective than pharmacologic therapy to reduce RV afterload and improve RV function. We compared RV size and function after aggressive medical unloading therapy to that achieved in the same patients after 3 months of left ventricular assist device (LVAD) support. Methods and Results We studied twenty patients who underwent isolated LVAD placement (9 pulsatile and 11 axial flow). Echocardiograms were performed after inpatient optimization with diuretic and inotropic therapy and compared to studies done after 3 months of LVAD support. After medical optimization right atrial pressure was 11±5 mm Hg, mean pulmonary artery pressure 36±11 mm Hg, pulmonary capillary wedge pressure 23±9 mm Hg, and cardiac index 2.0±0.6 L/min/m2. Pre-operatively, RV dysfunction was moderate (2.6 ±0.9 on 0-4 scale), RV diameter at the base was 3.1±0.6 cm, and mid-RV was 3.5±0.6 cm. After median LVAD support of 123 days (92-170), RV size and global RV dysfunction (2.6 ±0.9) failed to improve, despite reduced RV afterload. Conclusions RV dysfunction seen on intensive medical therapy persisted after 3 months of LVAD unloading therapy. Selection of candidates for isolated LV support should anticipate persistence of RV dysfunction observed on inotropic therapy. PMID:20206896

  7. Left Ventricular Relative Wall Thickness Versus Left Ventricular Mass Index in Non-Cardioembolic Stroke Patients

    PubMed Central

    Hashem, M-Sherif; Kalashyan, Hayrapet; Choy, Jonathan; Chiew, Soon K.; Shawki, Abdel-Hakim; Dawood, Ahmed H.; Becher, Harald

    2015-01-01

    Abstract In non-cardioembolic stroke patients, the cardiac manifestations of high blood pressure are of particular interest. Emerging data suggest that echocardiographically determined left ventricular hypertrophy is independently associated with risk of ischemic stroke. The primary objective of this study was to evaluate the frequency of different patterns of left ventricular (LV) remodeling and hypertrophy in a group of consecutive patients admitted with non-cardioembolic stroke or transient ischemic attack (TIA). In particular, we were interested in how often the relative wall thickness (RWT) was abnormal in patients with normal LV mass index (LVMI). As both abnormal RWT and LVMI indicate altered LV remodeling, the secondary objective of this research was to study whether a significant number of patients would be missing the diagnosis of LV remodeling if the RWT is not measured. All patients were referred within 48 hours after a stroke or a TIA for a clinically indicated transthoracic echocardiogram. The echocardiographic findings of consecutive patients with non-cardioembolic stroke or TIA were analyzed. All necessary measurements were performed in 368 patients, who were enrolled in the study. Mean age was 63.7 ± 12.5 years, 64.4% men. Concentric remodeling carried the highest frequency, 49.2%, followed by concentric hypertrophy, 30.7%, normal pattern, 15.5%, and eccentric hypertrophy, 4.1%. The frequency of abnormal left ventricular RWT (80.4%) was significantly higher than that of abnormal LVMI (35.3%), (McNemar P < 0.05). In this group of non-cardioembolic stroke patients, abnormal LV remodeling as assessed by relative wall thickness is very frequent. As RWT was often found without increased LV mass, the abnormal left ventricular geometry may be missed if RWT is not measured or reported. PMID:25997067

  8. Relation of magnetocardiographic arrhythmia risk parameters to delayed ventricular conduction in postinfarction ventricular tachycardia.

    PubMed

    Korhonen, Petri; Pesola, Katja; Järvinen, Antero; Mäkijärvi, Markku; Katila, Toivo; Toivonen, Lauri

    2002-09-01

    Time-domain late field and intra-QRS fragmentation parameters in magnetocardiography (MCG) identify patients prone to VT after myocardial infarction. This study investigated if they are related to slow ventricular conduction and affected by arrhythmia surgery. Twenty-two patients with old myocardial infarction undergoing map-guided subendocardial resection to treat sustained VT were included. Bipolar electrograms were recorded during operation using an epicardial jacket and endocardial balloon electrode array. The time from the QRS onset to the end of local ventricular excitation in each electrogram was measured during sinus rhythm. Multi-channel MCG was recorded before and after operation and filtered QRS duration (QRSd), root mean square amplitude of the magnetic field strength during the last 40 ms of the QRS complex (RMS40), duration of the low amplitude signal < 300 fT (LAS300), fragmentation index M (M), and fragmentation score S (S) were determined. All patients had one or two VT foci localized and resected. MCG parameters correlated with time to the latest end of ventricular excitation; r = 0.45 for QRSd (P = 0.035), r = 0.64 for M (P = 0.001), and r = 0.73 for S (P < 0.001). The correlations were even better in patients with anterior infarction (e.g., r = 0.87 for QRSd, P < 0.001; r = 0.91 for M, P < 0.001). The operation reduced the abnormalities in MCG parameters and 20 of the 21 patients tested postoperatively became noninducible. MCG parameters indicating postinfarction arrhythmia propensity are related to delayed ventricular conduction. Abolition of the arrhythmia substrate reverses the abnormality of these parameters. PMID:12380770

  9. [Case report: idiopathic ventricular tachycardia from the aortic sinus cusp].

    PubMed

    Tejera-Jurado, Luis Carlos; Nava, Santiago; Colín-Lizalde, Luis; Márquez, Manlio F; Gómez-Flores, Jorge; González-Hermosillo, Jesús Antonio; Iturralde-Torres, Pedro

    2009-01-01

    Idiopathic ventricular tachycardia is identified in 10% of the patients presenting with ventricular tachycardia, and they consist of various subtypes that can originate from different areas, including the aortic cusps which represent 0.7% of the total. Electrocardiographically, these ventricular tachycardias display a left bundle branch block pattern and inferior axis, and although rare, should be considered in the differential diagnosis with tachycardias originating from the septal region of the right ventricular outflow tract, which comprise 80% of the idiopathic ventricular tachycardias. Despite the vicinity of the left coronary artery ostium, radiofrequency catheter ablation can be curative in more than 90% of cases with a low risk (< 1% of serious complication). Therefore, it must be considered first-line therapy in patients who have failed or are intolerant to therapy with antiarrhythmic agents. The aim of this article is to describe the first case reported in Mexico of a successful ablation idiopathic ventricular tachycardia from the aortic sinus cusp in a patient with incessant ventricular tachycardia. PMID:19902669

  10. Mapping ventricular expansion onto cortical gray matter in older adults.

    PubMed

    Madsen, Sarah K; Gutman, Boris A; Joshi, Shantanu H; Toga, Arthur W; Jack, Clifford R; Weiner, Michael W; Thompson, Paul M

    2015-01-01

    Dynamic changes in the brain's lateral ventricles on magnetic resonance imaging are powerful biomarkers of disease progression in mild cognitive impairment (MCI) and Alzheimer's disease (AD). Ventricular measures can represent accumulation of diffuse brain atrophy with very high effect sizes. Despite having no direct role in cognition, ventricular expansion co-occurs with volumetric loss in gray and white matter structures. To better understand relationships between ventricular and cortical changes over time, we related ventricular expansion to atrophy in cognitively relevant cortical gray matter surfaces, which are more challenging to segment. In ADNI participants, percent change in ventricular volumes at 1-year (N = 677) and 2-year (N = 536) intervals was significantly associated with baseline cortical thickness and volume in the full sample controlling for age, sex, and diagnosis, and in MCI separately. Ventricular expansion in MCI was associated with thinner gray matter in frontal, temporal, and parietal regions affected by AD. Ventricular expansion reflects cortical atrophy in early AD, offering a useful biomarker for clinical trials of interventions to slow AD progression. PMID:25311280

  11. Evaluation of ventricular function in patients with coronary artery disease

    SciTech Connect

    Rocco, T.P.; Dilsizian, V.; Fischman, A.J.; Strauss, H.W.

    1989-07-01

    The recent expansion of interventional cardiovascular technologies has stimulated a concomitant expansion of noninvasive cardiac studies, both to assist in diagnosis and to evaluate treatment outcomes. Radionuclide ventricular function studies provide a reliable, reproducible means to quantify global left ventricular systolic performance, a critical determinant of prognosis in patients with cardiovascular disease. In addition, the ability to evaluate regional left ventricular wall motion and to assess ventricular performance during exercise have secured a fundamental role for such studies in the screening and treatment of patients with coronary artery disease. Radionuclide techniques have been extended to the evaluation of left ventricular relaxation/filling events, left ventricular systolic/diastolic function in the ambulatory setting, and with appropriate technical modifications, to the assessment of right ventricular performance at rest and with exercise. As a complement to radionuclide perfusion studies, cardiac blood-pool imaging allows for thorough noninvasive description of cardiac physiology and function in both normal subjects and in patients with a broad range of cardiovascular diseases. 122 references.

  12. Concentric left ventricular morphology in aerobically trained kayak canoeists.

    PubMed

    Gates, Phillip E; Campbell, Ian G; George, Keith P

    2004-09-01

    The aim of the present study was to test the hypothesis that upper body aerobically trained athletes (kayak canoeists) would have greater left ventricular wall thickness, but similar left ventricular diastolic chamber dimensions, compared with recreationally active and sedentary men. Ultrasound echocardiography was used to determine cardiac structure and function in highly trained kayak canoeists (n = 10), moderately active (n = 10) and sedentary men (n = 10). The septal and posterior left ventricular walls were approximately 0.2 cm thicker in kayak canoeists (P < 0.05), and left ventricular mass was 51% and 32% greater (P < 0.05) in canoeists than in the sedentary and moderately trained participants, respectively. There were no differences in left ventricular chamber dimension, suggesting that the kayak canoeists had a concentric pattern of left ventricular adaptation to aerobic upper body training. Scaling the data to body composition indices had no effect on the outcome of the statistical analysis. There were no differences in resting Doppler left ventricular diastolic or systolic function among the groups. Ejection fraction was lower in the kayak canoeists, but the magnitude of the difference was within the normal variability for this measurement. Thus aerobically upper body trained athletes demonstrated a concentric pattern of cardiac enlargement, but resting left ventricle function was not different between athletes, moderately active and sedentary individuals. PMID:15513280

  13. Arrhythmogenic right ventricular cardiomyopathy: contribution of different electrocardiographic techniques.

    PubMed

    Moreira, Davide; Delgado, Anne; Marmelo, Bruno; Correia, Emanuel; Gama, Pedro; Pipa, João; Nunes, Luís; Santos, Oliveira

    2014-04-01

    Arrhythmogenic right ventricular cardiomyopathy, also known as arrhythmogenic right ventricular dysplasia, is a condition in which myocardium is replaced by fibrous or fibrofatty tissue, predominantly in the right ventricle. It is clinically characterized by potentially lethal ventricular arrhythmias, and is a leading cause of sudden cardiac death. Its prevalence is not known exactly but is estimated at approximately 1:5000 in the adult population. Diagnosis can be on the basis of structural and functional alterations of the right ventricle, electrocardiographic abnormalities (including depolarization and repolarization alterations and ventricular arrhythmias) and family history. Diagnostic criteria facilitate the recognition and interpretation of non-specific clinical features of this disease. The authors present a case in which the diagnosis of arrhythmogenic right ventricular cardiomyopathy was prompted by the suspicion of right ventricular disease on transthoracic echocardiography. This was confirmed by detection of epsilon waves on analysis of the ECG, which generally go unnoticed but in this case were the key to the diagnosis. Their presence was also shown by non-conventional ECG techniques such as modified Fontaine ECG. The course of the disease culminated in the occurrence of ventricular tachycardia, which prompted placement of an implantable cardioverter-defibrillator. PMID:24780127

  14. Epicardial Ventricular Tachycardia Ablation for Which Patients?

    PubMed Central

    Roten, Laurent; Sacher, Frédéric; Daly, Matthew; Pascale, Patrizio; Komatsu, Yuki; Ramoul, Khaled; Scherr, Daniel; Chaumeil, Arnaud; Shah, Ashok; Denis, Arnaud; Derval, Nicolas; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre

    2012-01-01

    With the widespread use of implantable cardioverter-defibrillators, an increasing number of patients present with ventricular tachycardia (VT). Large multicentre studies have shown that ablation of VT successfully reduces recurrent VT and this procedure is being performed by an increasing number of centres. However, for a number of reasons, many patients experience VT recurrence after ablation. One important reason for VT recurrence is the presence of an epicardial substrate involved in the VT circuit which is not affected by endocardial ablation. Epicardial access and ablation is now frequently performed either after failed endocardial VT ablation or as first-line treatment in selected patients. This review will focus on the available evidence for identifying VT of epicardial origin, and discuss in which patients an epicardial approach would be benefitial. PMID:26835028

  15. CT of left ventricular assist devices.

    PubMed

    Carr, Carrie M; Jacob, Jaisy; Park, Soon J; Karon, Barry L; Williamson, Eric E; Araoz, Philip A

    2010-03-01

    Left ventricular assist devices (LVADs) have become an increasingly beneficial option for patients with heart failure, especially in light of the insufficient availability of donor hearts. LVADs have been used effectively in end-stage heart failure as a bridge to heart transplantation, as destination therapy for those ineligible for transplantation, or as a bridge to myocardial recovery. Presently, a wide variety of LVADs are being used therapeutically. Four different LVADs have been used at the authors' institution. The records of 42 patients who underwent implantation of 46 total LVADs during a 17-month period were reviewed; in 23 of these patients, computed tomography of the device was performed. Increased use of LVADs necessitates understanding of the normal positioning of a variety of these devices and recognition of potential complications, which include inflow and outflow cannula complications, postoperative hemorrhage, pericardial tamponade, thrombus formation, aortic valve stenosis, aortic valve insufficiency, right-sided heart failure, and infection. PMID:20228327

  16. Clinical Challenges in Catecholaminergic Polymorphic Ventricular Tachycardia.

    PubMed

    Imberti, Jacopo F; Underwood, Katherine; Mazzanti, Andrea; Priori, Silvia G

    2016-08-01

    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inheritable cardiac disorder associated with exercise- and stress-induced sudden death in young individuals. Although important steps forward have been made in the comprehension and treatment of this disease, several aspects remain unclear. Firstly, from an epidemiological standpoint the actual prevalence of CPVT is still unknown and possibly underestimated. In addition, the diagnostic process remains very challenging and can be supported by genetic analysis in only about half of the cases. Finally, up to one third of CPVT patients continue to present complex arrhythmias despite beta blocker treatment; the role of newer therapeutic options, such as flecainide and left cardiac sympathetic denervation, needs to be further elucidated. All these points constitute challenges for the cardiologist in the management of CPVT patients and fuel research into new diagnostic, prognostic and therapeutic approaches. PMID:26948768

  17. Ventricular fibrillation: triggers, mechanisms and therapies.

    PubMed

    Krummen, David E; Ho, Gordon; Villongco, Christopher T; Hayase, Justin; Schricker, Amir A

    2016-05-01

    Ventricular fibrillation (VF) is a common, life-threatening arrhythmia responsible for significant morbidity and mortality. Due to challenges in safely mapping VF, a comprehensive understanding of its mechanisms remains elusive. Recent findings have provided new insights into mechanisms that sustain early VF. Notably, the central role of electrical rotors and catheter-based ablation of VF rotor substrate have been recently reported. In this article, we will review data regarding four stages of VF: initiation, transition, maintenance and evolution. We will discuss the particular mechanisms for each stage and therapies targeting these mechanisms. We also examine inherited arrhythmia syndromes, including the mechanisms and therapies specific to each. We hope that the overview of VF outlined in this work will assist other investigators in designing future therapies to interrupt this life-threatening arrhythmia. PMID:27120223

  18. Coma due to malplaced external ventricular drain.

    PubMed

    Chai, Feng Yih; Farizal, Fadzil; Jegan, Thanabalan

    2013-01-01

    Ventriculostomy or external ventricular drain (EVD) placement by free-hand technique has a high malplacement rate. It is a blind procedure that often requires multiple attempts and revisions. To date, no neurological complication due to EVD malplacement has been reported in the literature. In this report, we present the first case of coma induced by a malplaced EVD and the patient regained consciousness after the drain was adjusted. Our discussion focused on various techniques that can improve the accuracy of EVD insertion. EVD insertion under image guidance provides better accuracy with limited disadvantages. We hypothesized that the patient's coma was due to the mass effect and irritation of the malplaced EVD exerted onto the ventral periaqueductal grey matter and the ascending neurons from upper brainstem. PMID:24101284

  19. Metastatic right ventricular mass with intracavitary obliteration

    PubMed Central

    Kalvakuri, Kavitha; Banga, Sandeep; Upalakalin, Nalinee; Shaw, Crystal; Davila, Wilmer Fernando; Mungee, Sudhir

    2016-01-01

    Metastatic cardiac tumors are more common than the primary cardiac tumors. Cervical cancer metastasizing outside of the pelvis is commonly spread to the lungs, liver, bones and lymph nodes than to the heart. Right-sided metastasis to the heart is more common than to the left side. Intramural spread is more common than intracavitary growth of metastatic cardiac tumors leading to delayed clinical presentation. Intracavitary mass can be confused with intracavitary thrombus which can be seen in the setting of pulmonary embolism. Transthoracic echocardiography plays a major role in the decision making and management of pulmonary embolism, and this modality can also be used to diagnose cardiac masses. Other modalities like TEE, cardiac CT, cardiac MRI and PET-CT scan have further utility in delineating these masses. This may help to plan appropriate management of the right ventricular mass particularly in cases where the patient history and CT pulmonary angiography results favor the diagnosis of pulmonary embolism. We present the case of a 49-year-old woman with a history of supracervical hysterectomy and salpingo-oophorectomy on oral estrogen therapy who was admitted with complaints of pleuritic chest pain and respiratory insufficiency after a long flight. Initial work-up showed sub-segmental pulmonary embolus in the right posterior lower lobe pulmonary artery, and the patient was managed on intravenous heparin. Lack of appropriate response to standard therapy led to further evaluation. Multimodality imaging and biopsies revealed a large right intracavitary ventricular metastatic squamous cell tumor, with the cervix as the primary source. PMID:27406457

  20. Abnormal right ventricular relaxation in pulmonary hypertension

    PubMed Central

    La Gerche, Andre; Roberts, Timothy J.; Prior, David L.; MacIsaac, Andrew I.; Burns, Andrew T.

    2015-01-01

    Abstract Left ventricular diastolic dysfunction is a well-described complication of systemic hypertension. However, less is known regarding the effect of chronic pressure overload on right ventricular (RV) diastolic function. We hypothesized that pulmonary hypertension (PHT) is associated with abnormal RV early relaxation and that this would be best shown by invasive pressure measurement. Twenty-five patients undergoing right heart catheterization for investigation of breathlessness and/or suspected PHT were studied. In addition to standard measurements, RV pressure was sampled with a high-fidelity micromanometer, and RV pressure/time curves were analyzed. Patients were divided into a PHT group and a non-PHT group on the basis of a derived mean pulmonary artery systolic pressure of 25 mmHg. Eleven patients were classified to the PHT group. This group had significantly higher RV minimum diastolic pressure ( vs. mmHg, ) and RV end-diastolic pressure (RVEDP; vs. mmHg, ), and RV τ was significantly prolonged ( vs. ms, ). There were strong correlations between RV τ and RV minimum diastolic pressure (, ) and between RV τ and RVEDP (, ). There was a trend toward increased RV contractility (end-systolic elastance) in the PHT group ( vs. mmHg/mL, ) and a correlation between RV systolic pressure and first derivative of maximum pressure change (, ). Stroke volumes were similar. Invasive measures of RV early relaxation are abnormal in patients with PHT, whereas measured contractility is static or increasing, which suggests that diastolic dysfunction may precede systolic dysfunction. Furthermore, there is a strong association between measures of RV relaxation and RV filling pressures. PMID:26064464

  1. Catheter Ablation of Fascicular Ventricular Tachycardia

    PubMed Central

    Liu, Yaowu; Fang, Zhen; Yang, Bing; Kojodjojo, Pipin; Chen, Hongwu; Ju, Weizhu; Cao, Kejiang; Chen, Minglong

    2015-01-01

    Background— Fascicular ventricular tachycardia (FVT) is a common form of sustained idiopathic left ventricular tachycardia with an Asian preponderance. This study aimed to prospectively investigate long-term clinical outcomes of patients undergoing ablation of FVT and identify predictors of arrhythmia recurrence. Methods and Results— Consecutive patients undergoing FVT ablation at a single tertiary center were enrolled. Activation mapping was performed to identify the earliest presystolic Purkinje potential during FVT that was targeted by radiofrequency ablation. Follow-up with clinic visits, ECG, and Holter monitoring was performed at least every 6 months. A total of 120 consecutive patients (mean age, 29.3±12.7 years; 82% men; all patients with normal ejection fraction) were enrolled. FVT involved left posterior fascicle and left anterior fascicle in 118 and 2 subjects, respectively. VT was noninducible in 3 patients, and ablation was acutely successful in 117 patients. With a median follow-up of 55.7 months, VT of a similar ECG morphology recurred in 17 patients, and repeat procedure confirmed FVT recurrence involving the same fascicle. Shorter VT cycle length was the only significant predictor of FVT recurrence (P=0.03). Six other patients developed new-onset upper septal FVT that was successfully ablated. Conclusions— Ablation of FVT guided by activation mapping is associated with a single procedural success rate without the use of antiarrhythmic drugs of 80.3%. Arrhythmia recurrences after an initially successful ablation were caused by recurrent FVT involving the same fascicle in two thirds of patients or new onset of upper septal FVT in the remainder. PMID:26386017

  2. Left Ventricular Diastolic Dysfunction in Peritoneal Dialysis

    PubMed Central

    Wu, Cho-Kai; Lee, Jen-Kuang; Wu, Yi-Fan; Tsai, Chia-Ti; Chiang, Fu-Tien; Hwang, Juey-Jen; Lin, Jiunn-Lee; Hung, Kuan-Yu; Huang, Jenq-Wen; Lin, Jou-Wei

    2015-01-01

    Abstract Left ventricular diastolic dysfunction (LVDD) is common among patients undergoing peritoneal dialysis (PD). We examined the relationship between LVDD, major adverse cardiovascular events (MACE), and mortality in PD patients. A total of 149 patients undergoing PD with preserved left ventricular systolic function were included and followed for 3.5 years. LVDD was diagnosed (according to the European Society of Cardiology guidelines) by conventional and tissue Doppler echocardiography. Serum high-sensitivity C-reactive protein (hsCRP) was measured. The location and volume of adipose tissue were assessed by computed tomography (CT) at the level of the fourth lumbar vertebra. Subjects with LVDD had higher levels of hsCRP, and more visceral and peritoneal fat than controls. The relationship between adjusted visceral adipose tissue and LVDD became nonsignificant when hsCRP and baseline demographic data were introduced into the logistic regression model (odds ratio = 1.52, P = 0.07). Subsequent hierarchical multivariate Cox regression analysis showed that LVDD was one of the most powerful determinants of MACE and mortality after adjusting for all confounding factors (hazard ratio [HR]: 1.71, 95% confidence interval [CI]: 1.43–3.51, P = 0.02 and HR: 2.25, 95% CI: 1.45–2.91, P = 0.04, respectively). Systemic inflammation (hsCRP) was also significantly associated with MACE and mortality (HR: 2.03, P = 0.03 and HR: 2.16, P = 0.04, respectively). LVDD is associated with systemic inflammation and increased visceral fat in patients undergoing PD. LVDD is also a sensitive, independent indicator of future MACE and mortality in PD patients. PMID:25997054

  3. Safety Testing of Left Ventricular Vent Valves.

    PubMed

    Gavin, Caroline; Coblentz, John; Acsell, Jeffrey R; Shackelford, Anthony G; Sistino, Joseph J

    2015-03-01

    Vent vacuum relief valves (VRVs) are used to limit the negative pressure at the ventricular vent catheter tip as well as prevent reversal of blood flow and prevention of air embolism. The purpose of this study was to evaluate the performance of three commercially available ventricular vent valves. The negative pressure at which the vent valve opened was measured at the valve inlet using high-fidelity pressure transducers. Also, the flow rate at which air entrainment occurred due to valve opening was recorded. Using a 51.5 cm column of saline, the resistance for each valve was calculated. The mean ± SD opening negative pressures were -231.3 ± 35.2 mmHg for the Quest Medical valve, -219.8 mmHg ± 17.2 for the Sorin valve, and -329.6 · 38.0 mmHg for the Terumo valve. The red Quest Medical valve opened at a lower flow (1.44 ± .03 L/min) than the dark blue Sorin valve (2.93 ± .01 L/min) and light blue LH130 Terumo valve (2.36 ± .02 L/min). The Sorin valve had the least resistance of 34.1 dyn-s/cm, followed by the Terumo LH130 valve resistance of 58.1 dyn·s/cm5, and the Quest Medical VRV-II valve with a resistance of 66.5 dyn·s/cm. We found that the valves are significantly different in the negative pressure generated. Understanding the limitations of these devices is important to reduce the occurrence of adverse events associated with venting and to select the best device for a specific clinical application. PMID:26390676

  4. Percutaneous Ventricular Assist Devices: New Deus Ex Machina?

    PubMed Central

    Arroyo, Diego; Cook, Stéphane

    2011-01-01

    The development of ventricular assist devices has broadened the means with which one can treat acute heart failure. Percutaneous ventricular assist devices (pVAD) have risen from recent technological advances. They are smaller, easier, and faster to implant, all important qualities in the setting of acute heart failure. The present paper briefly describes the functioning and assets of the most common devices used today. It gives an overview of the current evidence and indications for left ventricular assist device use in cardiogenic shock and high-risk percutaneous coronary intervention. Finally, extracorporeal life support devices are dealt with in the setting of hemodynamic support. PMID:22091361

  5. Right ventricular obstruction in various types of hypertrophic cardiomyopathy.

    PubMed

    Stierle, U; Sheikhzadeh, A; Shakibi, J G; Langbehn, A F; Diederich, K W

    1987-01-01

    Hypertrophic cardiomyopathy (HCM) is most probably a genetically transmitted disease with different clinical and hemodynamic features. In hypertrophic obstructive cardiomyopathy (HOCM) the obstruction is predominantly in the left ventricular outflow tract (IHSS). In a minority of cases the obstruction is strictly located in midventricle (midventricular obstruction, MO). Hypertrophic nonobstructive cardiomyopathy (HNCM) includes asymmetric septal hypertrophy (ASH) and apical hypertrophy (AH). Right ventricular hypertrophic obstruction (RVHO) is an uncommon type of HCM and is almost always combined with other types of left ventricular HCM. We describe in the present report 1 case of RVHO with IHSS, 2 cases with MO and, to our knowledge, the first case with AH. PMID:3599397

  6. Hypothyroid cardiomyopathy complicated by a left ventricular laminar thrombus.

    PubMed

    Van Treeck, Benjamin J; Masoud, Amgad G

    2014-01-01

    Clinical hypothyroidism is the most common hormone deficiency in the United States and is found in 0.3% of the U.S. population. It is associated with characteristic symptoms that can be readily identified by a careful history and physical examination. Hypothyroidism affects many bodily systems; in particular the cardiovascular system is impacted via multiple mechanisms.3 Occasionally hypothyroidism leads to transient left ventricular systolic dysfunction, termed hypothyroid cardiomyopathy. A rare sequela of this condition is a left ventricular thrombus, which has been described in two case reports thus far. Here we report a third case of reversible hypothyroid cardiomyopathy complicated by a left ventricular laminar thrombus. PMID:25438369

  7. Aprindine for treatment of ventricular arrhythmias in the dog.

    PubMed

    Muir, W W; Bonagura, J D

    1982-10-01

    Aprindine hydrochloride was administered IV and orally to 20 dogs with ventricular tachycardia. Seventeen of the 20 dogs had been unsuccessfully treated with conventional antiarrhythmic drugs. Fifteen of the 20 dogs converted to sinus rhythm after IV aprindine therapy, 4 dogs demonstrated marked slowing of their ventricular tachycardia, and 1 dog showed an increase in the rate of ventricular tachycardia. Emesis, ataxia, salivation, and nystamus were observed in 7 dogs after IV aprindine therapy. One dog developed clinical and laboratory evidence compatible with acute hepatitis. PMID:7149383

  8. The relationship between R-wave magnitude and ventricular volume during continuous left ventricular assist device assistance: experimental study.

    PubMed

    Fresiello, Libera; Trivella, Maria Giovanna; Di Molfetta, Arianna; Ferrari, Gianfranco; Bernini, Fabio; Meste, Olivier

    2015-05-01

    The current use of left ventricular assist devices (LVADs) as destination therapy is associated with the clinical need of monitoring patient-pump interaction. To this aim, the present work investigated the possibility of getting useful information about the status of the assisted left ventricle using electrocardiographic (ECG) data. A total of six animals, undergoing Gyro Centrifugal Pump 2 implantation (a new version of Gyro Centrifugal Pump C1E3 [Kyocera Corporation, Kyoto, Japan]) and CircuLite Synergy Micropump (CircuLite, Inc., Saddlebrooke, NJ, USA) in atrio-aortic connection, were analyzed. Data refer to different LVAD speeds with consequently different levels of ventricular unloading. From ECG signal, the R wave peak was individuated together with the corresponding left ventricular volume. Then on both signals, a moving average analysis was performed to reduce the effect of the ventilation. A regression and correlation analysis performed on the two resulting signals evidenced that the R wave peak and the ventricular volume are strictly related. Specifically, any change of LVAD speed, inducing a change in ventricular volume, is associated with a change in R wave peak value. The present work is a first step in investigating the usefulness of the ECG signal during LVAD therapy, for the monitoring of mechanical parameters of the heart such as the ventricular volumes. The correlation found between the ECG and the ventricular volume can be a promising starting point for possible future noninvasive LVAD patient monitoring. PMID:25377695

  9. Birth weight-related percentiles of brain ventricular system as a tool for assessment of posthemorrhagic hydrocephalus and ventricular enlargement.

    PubMed

    Hartenstein, Sebastian; Bamberg, Christian; Proquitté, Hans; Metze, Boris; Bührer, Christoph; Schmitz, Thomas

    2016-03-01

    Besides remarkable improvements of neonatal medical therapy, neurological morbidity remains a major concern in preterm infants. In particular, intracranial hemorrhage is a severe complication strongly correlated to poor neurological outcome. For early clinical assessment of intracranial hemorrhage and its impact on the ventricular system, cranial sonography is an important bedside diagnostic tool. Reference values of ventricular sizes are available in relation to gestational age (GA). So far, it has not been demonstrated that ventricular size values are also reliable in relation to birth weight (BW). In this study, we performed cranial ultrasonography in 250 preterm and term newborn infants. Measurements of the intracranial ventricular system by cranial ultrasound examination were performed within 72 h after birth. We determined ventricular index, anterior horn width, width of the third ventricle, width and length of the fourth ventricle for statistical analysis in relation to BW and GA. GA ranged from 23 weeks, 3 days to 42 weeks, 1 day (mean: 33 weeks), BW ranged from 345 to 5620 g (mean: 2146 g). Ventricular index and fourth ventricle width revealed a significant correlation to birth weight with r=0.75, each. A significant correlation to birth weight was also obtained for width and length of the third ventricle (r=0.55 and 0.47, respectively). Correlations obtained for ventricular measures in relation to GA were similar to those referring to BW. In preterm and term infants, ventricular sizes in relation to BW seem reliable for assessment and monitoring of ventricular pathologies, i.e. after intracranial hemorrhage. PMID:26378487

  10. A Case of Cough-induced Ventricular Tachycardia in a Patient with a Left Ventricular Assist Device.

    PubMed

    Ruckdeschel, Emily Sue; Wolfel, Eugene; Nguyen, Duy Thai

    2016-03-01

    In this case, the patient's ventricular tachycardia (VT) was specifically induced by coughing, which has not previously been described. Decreasing the rotational speed of the left ventricular assist device (LVAD) and increasing preload by stopping the patient's nitrates and reducing diuretic dose allowed improved filling of the left ventricle (LV) and increased LV volumes. When coughing recurred, the effects on the LV cavity were less pronounced and thus VT was reduced. Although ventricular arrhythmias are common after LVAD placement, this is a unique case in which VT was caused by coughing, which is ordinarily not considered arrhythmogenic. PMID:26920187

  11. Norwood Stage 1 With Surgical Ventricular Reconstruction and Mitral Valve Repair for Neonatal Idiopathic Left Ventricular Dilated Cardiomyopathy.

    PubMed

    Myers, Patrick O; Sologashvili, Tornike; Beghetti, Maurice; Tissot, Cécile

    2016-07-01

    A newborn girl presented with a prenatal diagnosis of dilated left ventricular cardiomyopathy, mitral valve regurgitation, and ductal-dependent circulation. The left ventricle was severely dilated and hypokinetic. The patient underwent Norwood stage 1 single ventricle palliation with a Damus-Kaye-Stansel anastomosis, atrioseptectomy, and a modified Blalock-Taussig shunt. The left ventricle was managed with Batista surgical ventricular reconstruction, with resection of the dilated and thinned ventricular myocardium, along with periventricular Alfieri repair of the mitral valve. The patient had an uneventful postoperative recovery, followed by stage 2 bidirectional Glenn and tricuspid valvuloplasty at 2.75 months of age. PMID:27343520

  12. The Importance of Purkinje Activation in Long Duration Ventricular Fibrillation

    PubMed Central

    Huang, Jian; Dosdall, Derek J.; Cheng, Kang‐An; Li, Li; Rogers, Jack M.; Ideker, Raymond E.

    2014-01-01

    Background The mechanisms that maintain long duration ventricular fibrillation (LDVF) are unclear. The difference in distribution of the Purkinje system in dogs and pigs was explored to determine if Purkinje activation propagates to stimulate working myocardium (WM) during LDVF and WM pacing. Methods and Results In‐vivo extracellular recordings were made from 1044 intramural plunge and epicardial plaque electrodes in 6 pig and 6 dog hearts. Sinus activation propagated sequentially from the endocardium to the epicardium in dogs but not pigs. During epicardial pacing, activation propagated along the endocardium and traversed the LV wall almost parallel to the epicardium in dogs, but in pigs propagated away from the pacing site approximately perpendicular to the epicardium. After 1 minute of VF, activation rate near the endocardium was significantly faster than near the epicardium in dogs (P<0.01) but not pigs (P>0.05). From 2 to 10 minutes of LDVF, recordings exhibiting Purkinje activations were near the endocardium in dogs (P<0.01) but were scattered transmurally in pigs, and the WM activation rate in recordings in which Purkinje activations were present was significantly faster than the WM activation rate in recordings in which Purkinje activations were absent (P<0.01). In 10 isolated perfused dog hearts, the LV endocardium was exposed and 2 microelectrodes were inserted into Purkinje and adjacent myocardial cells. After 5 minutes of LDVF, mean Purkinje activation rate was significantly faster than mean WM activation rate (P<0.01). Conclusion These extracellular and intracellular findings about activation support the hypothesis that Purkinje activation propagates to stimulate WM during sinus rhythm, pacing, and LDVF. PMID:24584738

  13. l-Arginine currents in rat cardiac ventricular myocytes

    PubMed Central

    Peluffo, R Daniel

    2007-01-01

    l-Arginine (l-Arg) is a basic amino acid that plays a central role in the biosynthesis of nitric oxide, creatine, agmantine, polyamines, proline and glutamate. Most tissues, including myocardium, must import l-Arg from the circulation to ensure adequate intracellular levels of this amino acid. This study reports novel l-Arg-activated inward currents in whole-cell voltage-clamped rat ventricular cardiomyocytes. Ion-substitution experiments identified extracellular l-Arg as the charge-carrying cationic species responsible for these currents, which, thus, represent l-Arg import into cardiac myocytes. This result was independently confirmed by an increase in myocyte nitric oxide production upon extracellular application of l-Arg. The inward movement of Arg molecules was found to be passive and independent of Na2+, K2+, Ca2+ and Mg2+. The process displayed saturation and membrane potential (Vm)-dependent kinetics, with a K0.5 for l-Arg that increased from 5 mm at hyperpolarizing Vm to 20 mm at +40 mV. l-Lysine and l-ornithine but not d-Arg produced currents with characteristics similar to that activated by l-Arg indicating that the transport process is stereospecific for cationic l-amino acids. l-Arg current was fully blocked after brief incubation with 0.2 mmN-ethylmaleimide. These features suggest that the activity of the low-affinity, high-capacity CAT-2A member of the y2+ family of transporters is responsible for l-Arg currents in acutely isolated cardiomyocytes. Regardless of the mechanism, we hypothesize that a low-affinity arginine transport process in heart, by ensuring substrate availability for sustained NO production, might play a cardio-protective role during catabolic states known to increase Arg plasma levels severalfold. PMID:17303641

  14. Eisenmenger ventricular septal defect in a Humboldt penguin (Spheniscus humboldti).

    PubMed

    Laughlin, D S; Ialeggio, D M; Trupkiewicz, J G; Sleeper, M M

    2016-09-01

    The Eisenmenger ventricular septal defect is an uncommon type of ventricular septal defect characterised in humans by a traditionally perimembranous ventricular septal defect, anterior deviation (cranioventral deviation in small animal patients) of the muscular outlet septum causing malalignment relative to the remainder of the muscular septum, and overriding of the aortic valve. This anomaly is reported infrequently in human patients and was identified in a 45-day-old Humboldt Penguin, Spheniscus humboldti, with signs of poor growth and a cardiac murmur. This case report describes the findings in this penguin and summarises the anatomy and classification of this cardiac anomaly. To the authors' knowledge this is the first report of an Eisenmenger ventricular septal defect in a veterinary patient. PMID:27286906

  15. How best to assess right ventricular function by echocardiography*

    PubMed Central

    DiLorenzo, Michael P.; Bhatt, Shivani M.; Mercer-Rosa, Laura

    2016-01-01

    Right ventricular function is a crucial determinant of long-term outcomes of children with heart disease. Quantification of right ventricular systolic and diastolic performance by echocardiography is of paramount importance, given the prevalence of children with heart disease, particularly those with involvement of the right heart, such as single or systemic right ventricles, tetralogy of Fallot, and pulmonary arterial hypertension. Identification of poor right ventricular performance can provide an opportunity to intervene. In this review, we will go through the different systolic and diastolic indices, as well as their application in practice. Quantification of right ventricular function is possible and should be routinely performed using a combination of different measures, taking into account each disease state. Quantification is extremely useful for individual patient follow-up. Laboratories should continue to strive to optimise reproducibility through quality improvement and quality assurance efforts in addition to investing in technology and training for new, promising techniques, such as three-dimensional echocardiography. PMID:26675593

  16. [Fascicular ventricular tachycardia in a 49-year-old patient].

    PubMed

    Bellmann, Barbara; Nagel, Patrick; Tscholl, Verena; Roser, Mattias; Rillig, Andreas

    2016-06-01

    We report a 49-year-old patient who presented with tachycardia in our emergency room. The 12-lead ECG showed a wide complex tachycardia with a heart rate of 234 beats per minute. After structural heart disease was excluded via echocardiography, coronary angiography and magnetic resonance imaging, an electrophysiological study was performed. During programmed ventricular stimulation, a fascicular tachycardia was induced, which was successfully treated by radiofrequency ablation. Fascicular ventricular tachycardia is a rare tachycardia that occurs in patients without structural heart disease. Radiofrequency ablation can be performed safely and shows a high success rate. Differential diagnoses of fascicular ventricular tachycardias are substrate-based ventricular tachycardia and supraventricular tachycardia. PMID:27193769

  17. Ventricular assist devices and non-cardiac surgery.

    PubMed

    Roberts, S Michael; Hovord, David G; Kodavatiganti, Ramesh; Sathishkumar, Subramanian

    2015-01-01

    The use of ventricular assist devices has expanded significantly since their approval by the Food and Drug Administration in the United States in 1994. In addition to this, the prevalence of heart failure continues to increase. We aim to provide an overview of perioperative considerations and management of these patients for non-cardiac surgery. We performed a Medline search for the words "ventricular assist device," "Heartmate" and "HeartWare" to gain an overview of the literature surrounding these devices, and chose studies with relevance to the stated aims of this review. Patients with ventricular assist devices are presenting more frequently for surgery not related to their cardiac pathology. As the mechanically supported population grows, general anesthesiologists will be faced with managing these patients, possibly outside of the tertiary care setting. The unique challenges of this patient population can best be addressed by a thorough understanding of ventricular assist device physiology and a multidisciplinary approach to care. PMID:26685884

  18. Idiopathic Paroxysmal Ventricular Tachycardia in Infants and Children

    ERIC Educational Resources Information Center

    Hernandez, Antonio; And Others

    1975-01-01

    Laboratory tests including blood count serum electrolyte measures, and electroencephalograms were performed on seven children ages 1 day to 18 years with recurrent attacks of rapid heart action known as idiopathic paroxysmal ventricular tachycardia. (CL)

  19. Left ventricular assist devices-current state and perspectives.

    PubMed

    Prinzing, Anatol; Herold, Ulf; Berkefeld, Anna; Krane, Markus; Lange, Rüdiger; Voss, Bernhard

    2016-08-01

    Mechanical circulatory support devices have become an important treatment tool for severe acute and chronic heart failure, since heart transplantation cannot meet the demands because of a lack of available donor organs. Since implantation of the first ventricular assist device a constant development of the suitability of these devices has been made. This review will introduce different generations of left ventricular assist devices (LVAD) and elaborate on clinical indications, risk stratification and current literature. PMID:27621895

  20. Ventricular Assist Devices (VAD) Therapy: New Technology, New Hope?

    PubMed Central

    Rodriguez, Limael E.; Suarez, Erik E.; Loebe, Matthias; Bruckner, Brian A.

    2013-01-01

    Ventricular assist devices are commonly utilized in the treatment of end-stage heart failure. Advances in continuous flow technology have improved efficiency, size, implantability, extended support, and overall patient outcomes. This has led to an expanded role of left ventricular assist device (LVAD) clinical use and applications. This review describes the advances and current state of LVAD devices and provides a future outlook for this technology. PMID:23519193

  1. Ultrasound stylet for non-image-guided ventricular catheterization.

    PubMed

    Coulson, Nathaniel K; Chiarelli, Peter A; Su, David K; Chang, Jason J; MacConaghy, Brian; Murthy, Revathi; Toms, Peter; Robb, Terrence L; Ellenbogen, Richard G; Browd, Samuel R; Mourad, Pierre D

    2015-10-01

    OBJECT Urgent ventriculostomy placement can be a lifesaving procedure in the setting of hydrocephalus or elevated intracranial pressure. While external ventricular drain (EVD) insertion is common, there remains a high rate of suboptimal drain placement. Here, the authors seek to demonstrate the feasibility of an ultrasound-based guidance system that can be inserted into an existing EVD catheter to provide a linear ultrasound trace that guides the user toward the ventricle. METHODS The ultrasound stylet was constructed as a thin metal tube, with dimensions equivalent to standard catheter stylets, bearing a single-element, ceramic ultrasound transducer at the tip. Ultrasound backscatter signals from the porcine ventricle were processed by custom electronics to offer real-time information about ventricular location relative to the catheter. Data collected from the prototype device were compared with reference measurements obtained using standard clinical ultrasound imaging. RESULTS A study of porcine ventricular catheterization using the experimental device yielded a high rate of successful catheter placement after a single pass (10 of 12 trials), despite the small size of pig ventricles and the lack of prior instruction on porcine ventricular architecture. A characteristic double-peak signal was identified, which originated from ultrasound reflections off of the near and far ventricular walls. Ventricular dimensions, as obtained from the width between peaks, were in agreement with standard ultrasound reference measurements (p < 0.05). Furthermore, linear ultrasound backscatter data permitted in situ measurement of the stylet distance to the ventricular wall (p < 0.05), which assisted in catheter guidance. CONCLUSIONS The authors have demonstrated the ability of the prototype ultrasound stylet to guide ventricular access in the porcine brain. The alternative design of the device makes it potentially easy to integrate into the standard workflow for bedside EVD

  2. Left ventricular assist devices—current state and perspectives

    PubMed Central

    Herold, Ulf; Berkefeld, Anna; Krane, Markus; Lange, Rüdiger; Voss, Bernhard

    2016-01-01

    Mechanical circulatory support devices have become an important treatment tool for severe acute and chronic heart failure, since heart transplantation cannot meet the demands because of a lack of available donor organs. Since implantation of the first ventricular assist device a constant development of the suitability of these devices has been made. This review will introduce different generations of left ventricular assist devices (LVAD) and elaborate on clinical indications, risk stratification and current literature. PMID:27621895

  3. Left ventricular endocardial ecchinococcosis associated with multiple intracranial hydatid cysts

    PubMed Central

    2013-01-01

    Cardiac ecchinococcosis is a rare disease. Its incidence varies from 0.02-2%. Commonly seen in the left ventricle arising from the myocardium in the subepicardial region. We report a 15-year-old boy presented with a rare combination of a left ventricular subendocardial hydatid cyst associated with multiple cysts in the left cerebral hemisphere and right posterior occipital lobe. The patient underwent successful surgical excision of the left ventricular hydatid cyst using cardiopulmonary bypass. PMID:23601473

  4. [Electrical aspects of experimental diastolic and mixed ventricular overload].

    PubMed

    de Micheli, A; Medrano, G A; Casanova, J M

    1990-01-01

    Hemodynamic and electrical adaptation of ventricular myocardium to progressive diastolic and combined overloads was studied in mongrel dogs weighing between 15 and 20 Kg, anesthetized with intraperitoneal sodium pentobarbital (35 mg/Kg). Unipolar epicardial and intracavitary records as well as corresponding ventricular pressure curves were obtained every 30 mn after infusion was begun. The systolic arterial pressure was followed continuously by a mercury manometer. Right ventricular overload was produced by means of continuous venous infusion of saline solution in a group of 115 dogs with open pericardium (Series A) and in another of 45 dogs with intact pericardium (Series B). In Series A, right proximal and peripheral blocks were present in all the cases, beginning at 180 mn of infusion. In Series B, at 210 mn blocks were not present in 18 dogs (40%), and right peripheral blocks were present in 27 (60%). Left ventricular overload was obtained through continuous infusion of saline serum into left atria of 31 dogs with open pericardium (Series A1) and of another 50 with intact pericardium (Series B1). Only peripheral left blocks appeared in both series. Between 240 and 300 mn of infusion, the percentage of surviving animals was greater in Series B1, with a statistically significant difference at 270 and 300 mn. The pericardium seems to hinder the adaptation of right ventricular myocardium to the overloads evaluated, while it seems to help the response of the left ventricular myocardium to diastolic and combined overload. PMID:2344221

  5. Mild carbon monoxide poisoning impairs left ventricular diastolic function

    PubMed Central

    Çiftçi, Özgür; Günday, Murat; Çalışkan, Mustafa; Güllü, Hakan; Doğan, Rafi; Güven, Aytekin; Müderrisoğlu, Haldun

    2013-01-01

    Rationale: Carbon monoxide (CO) poisoning is associated with direct cardiovascular toxicity. In mild CO poisoning in which cardiovascular life support is not required, the effects of CO on left and right ventricular functions are unknown in patients without cardiac failure. Objectives: Echocardiography was used to determine whether or not mild CO poisoning impairs ventricular function. Twenty otherwise healthy patients with CO poisoning and 20 age- and gender-matched controls were studied. Echocardiographic examinations were performed at the time of admission and 1 week after poisoning. Results: The impairment observed in the left and right ventricular diastolic function at the time of admission was greater than the impairment 1 week after poisoning. Mild CO poisoning did not have a significant effect on systolic function. Carboxyhemoglobin levels were positively correlated with left ventricular diastolic dysfunction, whereas the levels were not correlated with right ventricular diastolic function. Conclusions: In CO intoxication, the development of left and right ventricular diastolic dysfunction precedes systolic abnormality. Patients with mild CO poisoning do not manifest cardiovascular symptoms; however, it should be borne in mind that most of these patients have myocardial involvement. PMID:24082611

  6. Mechanism of shock associated with right ventricular infarction.

    PubMed Central

    Creamer, J E; Edwards, J D; Nightingale, P

    1991-01-01

    Various mechanisms have been proposed to explain the shock sometimes associated with right ventricular infarction, but only small numbers of patients with clinical shock have been studied. The haemodynamic profiles of seven patients with clinical cardiogenic shock after right ventricular myocardial infarction were studied prospectively. They were selected because all had a stable cardiac rhythm and none had absolute hypovolaemia during the study period. In all of them the mean right atrial pressure exceeded the pulmonary artery occlusion pressure. After treatment with varying combinations of dopamine, dobutamine, and glyceryl trinitrate (titrated to achieve the optimum haemodynamic response) the mean systemic arterial pressure increased, as did the cardiac index. There was an associated increase in the left ventricular stroke work index but the right ventricular stroke work index was unchanged. There was no significant change in heart rate, mean right atrial pressure, or pulmonary artery occlusion pressure. This suggests that the probable mechanism of the shock associated with right ventricular infarction is concomitant severe left ventricular dysfunction. PMID:1867948

  7. The helical ventricular myocardial band of Torrent-Guasp.

    PubMed

    Kocica, Mladen J; Corno, Antonio F; Lackovic, Vesna; Kanjuh, Vladimir I

    2007-01-01

    We live in an era of substantial progress in understanding myocardial structure and function at genetic, molecular, and microscopic levels. Yet, ventricular myocardium has proven remarkably resistant to macroscopic analyses of functional anatomy. Pronounced and practically indefinite global and local structural anisotropy of its fibers and other ventricular wall constituents produces electrical and mechanical properties that are nonlinear, anisotropic, time varying, and spatially inhomogeneous. The helical ventricular myocardial band of Torrent-Guasp is a revolutionary new concept in understanding global, 3-dimensional, functional architecture of the ventricular myocardium. This concept defines the principal, cumulative vectors, integrating the tissue architecture (ie, form) and net forces developed (ie, function) within the ventricular mass. The primary purpose of this review is to emphasize the importance of this concept, in the light of collaborative efforts to establish an integrative approach, defining ventricular form and function by linking across multiple scales of biological organization, as explained in the ongoing Physiome project. Because one of the most important scientific missions in this century is integration of basic research with clinical medicine, we believe that this knowledge is not of merely academic importance, but is also the essential prerequisite in clinical evaluation and treatment of different heart diseases. PMID:17433993

  8. Unruptured Sinus of Valsalva Aneurysm with Right Ventricular Outflow Tract Obstruction and Supracristal Ventricular Septal Defect: A Rare Case

    PubMed Central

    Sadiq, Muhammad Athar; Ahmad, Wan Azman Wan; Supuramaniam, Chitra; Watson, Timothy; Abidin, Imran Zainal; Chee, Kok Han

    2015-01-01

    Unruptured right sinus of Valsalva aneurysm that causes severe obstruction of the right ventricular outflow tract is extremely rare. We describe the case of a 47-year-old woman who presented with exertional dyspnea. Upon investigation, we discovered an unruptured right sinus of Valsalva aneurysm with associated right ventricular outflow tract obstruction and a supracristal ventricular septal defect. To our knowledge, only 2 such cases have previously been reported in the medical literature. Although treatment of unruptured sinus of Valsalva aneurysm remains debatable, surgery should be considered for extremely large aneurysms or for progressive enlargement of the aneurysm on serial evaluation. Surgery was undertaken in our patient because there was clear evidence of right ventricular outflow tract obstruction, right-sided heart dilation, and associated exertional dyspnea. PMID:26504442

  9. Relationship Between MDCT‐Imaged Myocardial Fat and Ventricular Tachycardia Substrate in Arrhythmogenic Right Ventricular Cardiomyopathy

    PubMed Central

    Komatsu, Yuki; Jadidi, Amir; Sacher, Frederic; Denis, Arnaud; Daly, Matthew; Derval, Nicolas; Shah, Ashok; Lehrmann, Heiko; Park, Chan‐Il; Weber, Reinhold; Arentz, Thomas; Pache, Gregor; Sermesant, Maxime; Ayache, Nicholas; Relan, Jatin; Montaudon, Michel; Laurent, François; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre; Cochet, Hubert

    2014-01-01

    Background Myocardial fibrofatty infiltration is a milieu for ventricular tachycardia (VT) in arrhythmogenic right ventricular cardiomyopathy (ARVC) and can be depicted as myocardial hypodensity on contrast‐enhanced multidetector computed tomography (MDCT) with high spatial and temporal resolution. This study aimed to assess the relationship between MDCT‐imaged myocardial fat and VT substrate in ARVC. Methods and Results We studied 16 patients with ARVC who underwent ablation and preprocedural MDCT. High‐resolution imaging data were processed and registered to high‐density endocardial and epicardial maps in sinus rhythm on 3‐dimensional electroanatomic mapping (3D‐EAM) (626±335 and 575±279 points/map, respectively). Analysis of the locations of low‐voltage and fat segmentation included the following endocardial and epicardial regions: apex, mid (anterior, lateral, inferior), and basal (anterior, lateral, inferior). The location of local abnormal ventricular activities (LAVA) was compared with fat distribution. RV myocardial fat was successfully segmented and integrated with 3D‐EAM in all patients. The κ agreement test demonstrated a good concordance between the epicardial low voltage and fat (κ=0.69, 95% CI 0.54 to 0.84), but fair concordance with the endocardium (κ=0.41, 95% CI 0.27 to 0.56). The majority of LAVA (520/653 [80%]) were located within the RV fat segmentation, of which 90% were not farther than 20 mm from its border. Registration of MDCT allowed direct visualization of the coronary arteries, thus avoiding coronary damage during epicardial radiofrequency delivery. Conclusions The integration of MDCT‐imaged myocardial fat with 3D‐EAM provides valuable information on the extent and localization of VT substrate and demonstrates ablation targets clustering in its border region. PMID:25103203

  10. Left ventricular mechanics and arterial-ventricular coupling following high-intensity interval exercise

    PubMed Central

    Cote, Anita T.; Bredin, Shannon S. D.; Phillips, Aaron A.; Koehle, Michael S.; Glier, Melissa B.; Devlin, Angela M.

    2013-01-01

    High-intensity exercise induces marked physiological stress affecting the secretion of catecholamines. Sustained elevations in catecholamines are thought to desensitize cardiac beta receptors and may be a possible mechanism in impaired cardiac function following strenuous exercise. In addition, attenuated arterial-ventricular coupling may identify vascular mechanisms in connection with postexercise attenuations in ventricular function. Thirty-nine normally active (NA) and endurance-trained (ET) men and women completed an echocardiographic evaluation of left ventricular function before and after an acute bout of high-intensity interval exercise (15 bouts of 1:2 min work:recovery cycling: 100% peak power output and 50 W, respectively). Following exercise, time to peak twist and peak untwisting velocity were delayed (P < 0.01) but did not differ by sex or training status. Interactions for sex and condition (rest vs. exercise) were found for longitudinal diastolic strain rate (men, 1.46 ± 0.19 to 1.28 ± 0.23 s−1 vs. women, 1.62 ± 0.25 to 1.63 ± 0.26 s−1; P = 0.01) and arterial elastance (men 2.20 ± 0.65 to 3.24 ± 1.02 mmHg·ml−1·m−2 vs. women 2.51 ± 0.61 to 2.93 ± 0.68 mmHg·ml−1·m−2; P = 0.04). No cardiac variables were found associated with catecholamine levels. The change in twist mechanics was associated with baseline aortic pulse-wave velocity (r2 = 0.27, P = 0.001). We conclude that males display greater reductions in contractility in response to high-intensity interval exercise, independent of catecholamine concentrations. Furthermore, a novel association of arterial stiffness and twist mechanics following high-intensity acute exercise illustrates the influence of vascular integrity on cardiac mechanics. PMID:24052036

  11. Vibration isolation

    NASA Technical Reports Server (NTRS)

    Bastin, Paul

    1990-01-01

    Viewgraphs on vibration isolation are presented. Techniques to control and isolate centrifuge disturbances were identified. Topics covered include: disturbance sources in the microgravity environment; microgravity assessment criteria; life sciences centrifuge; flight support equipment for launch; active vibration isolation system; active balancing system; and fuzzy logic control.

  12. [The process of ventricular remodeling after acute myocardial infarct associated with left ventricular aneurysm and ventricular septum rupture treated with radical surgery].

    PubMed

    Hůla, J

    1997-01-01

    Even after a successful operation of mechanical complications on account of acute myocardial infarction gradually developing adverse remodelling of the left ventricle has to be envisaged. In a six-year clinical study by means of echocardiography the authors followed up systematically some cardiac dimensions and volumes and functional systolic and diastolic left ventricular parameters. The changes pertained in particular to the endsystolic and enddiastolic volume, the ejection fraction, the peak maximum rate, early and late diastolic filling and their ratio as well as to indirect values of the mean pressure in the pulmonary artery. These changes, which at first indicated impaired relaxation, are caused subsequently by increasing stiffness of the left ventricle. With regard to the large number of complicated pathophysiological phenomena pertaining to active relaxation and passive elastic properties of the left ventricle during ventricular diastole, different Doppler parameters must be evaluated very carefully, individually and with regard to the clinical condition. Attention is drawn to the importance of complicating mitral regurgitations and an increased pressure in the left atrium and lesser circulation after aneurysmectomy of the left ventricle. Mitral regurgitation has an impact on the process of left ventricular filling investigated by means of diastolic Doppler functions. Despite limitations of echocardiographic methods within the framework of assessment of diastolic left ventricular functions after myocardial infarction echocardiography remains the main means for evaluating left ventricular function by a non-invasive route and its position in this respect is irreplaceable. Further experimental work is needed for better understanding, use and more intelligent interpretation of non-invasive parameters of left ventricular function also in these complicated conditions after surgery of mechanical complications resulting from myocardial infarction. PMID:9221569

  13. Predictors of Increased Left Ventricular Filling Pressure in Dialysis Patients with Preserved Left Ventricular Ejection Fraction

    PubMed Central

    Bajraktari, Gani; Berbatovci-Ukimeraj, Mimoza; Hajdari, Ali; Ibraimi, Lavdim; Daullxhiu, Irfan; Elezi, Ymer; Ndrepepa, Gjin

    2009-01-01

    Aim To study the left and right ventricular function and to assess the predictors of increased left ventricular (LV) filling pressure in dialysis patients with preserved LV ejection fraction. Methods This study included 63 consecutive patients (age 57 ± 14 years, 57% women) with end-stage renal failure. Echocardiography, including tissue Doppler measurements, was performed in all patients. Based on the median value of the ratio of transmitral early diastolic velocity to early myocardial velocity (E/E’ ratio), patients were divided into 2 groups: the group with high filling pressure (E/E’>10.16) and the group with low filling pressure (E/E’≤10.16). Results Compared with patients with low filling pressure, the group of patients with high filling pressure included a higher proportion of diabetic patients (41% vs 13%, P = 0.022) and had greater LV mass index (211 ± 77 vs 172 ± 71 g/m3, P = 0.04), lower LV lateral long axis amplitude (1.4 ± 0.3 vs 1.6 ± 0.3 cm, P = 0.01), higher E wave (84 ± 19 vs 64 ± 18cm/s, P < 0.001), lower systolic myocardial velocity (S’:8.6 ± 1.5 vs 7.0 ± 1.3 cm/s, P < 0.001), and lower diastolic myocardial velocities (E’: 6.3 ± 1.9 vs 9.5 ± 2.9 cm/s, P < 0.001; A’: 8.4 ± 1.9 vs 9.7 ± 2.5 cm/s, P = 0.018). Multivariate analysis identified LV systolic myocardial velocity – S’ wave (adjusted odds ratio, 1.909; 95% confidence interval, 1.060-3.439; P = 0.031) and age (1.053; 1.001-1.108; P = 0.048) as the only independent predictors of high LV filling pressure in dialysis patients. Conclusions In dialysis patients with preserved left ventricular ejection fraction, reduced systolic myocardial velocity and elderly age are independent predictors of increased left ventricular filling pressure. PMID:20017222

  14. Unidirectional ventricular septal valved patch for repair of late presenting ventricular septal defect with aortopulmonary window

    PubMed Central

    Makhija, Neeti; Narula, Jitin; Keshri, Vikas Kumar; Gupta, Saurabh Kumar; Talwar, Sachin

    2016-01-01

    Management of long standing left to right shunt lesion resulting in elevated pulmonary vascular resistance (PVR) is challenging. Limited surgical options are further complicated by an unpredictable postoperative period. Unidirectional valve patch (UVP) closure has shown to be useful in cases of the large ventricular septal defect (VSD) who present late. We report a case of large aortopulmonary window coexisting with a large VSD with severe pulmonary artery hypertension and significantly elevated PVR that was managed surgically by closure of the window by sandwich technique and closure of the septal defect with a UVP. This report emphasizes the importance of UVP in the management of such patients. PMID:27011704

  15. Ventricular defibrillation combining DC electrical field and electrical pacing: an optical mapping study

    NASA Astrophysics Data System (ADS)

    Musunuri, Sai Shruthi; Tang, Liang; Joung, Boyoung; Berbari, Edward J.; Lin, Shien-Fong

    2009-02-01

    Although high voltage direct current (DC) shock is a standard technique to terminate ventricular fibrillation (VF), it can cause severe pain and tissue damage. The exact effect of the DC electric field, which can depolarize the heart during VF is still unknown. We hypothesized that low-energy DC field in combination with pacing (pacing+DC) could terminate VF by affecting the ventricular propagation pattern. In six Langendorff-perfused isolated rabbit hearts with the ablated sinoatrial (SA) node, the DC field was delivered to the left ventricle (cathode) and right ventricle (anode). We designed a timed protocol using LabVIEW programming that delivers pacing, DC and pacing+DC stimuli for two seconds time intervals each. The pacing pulse (with varying pacing cycle length: 300ms-30ms) was delivered to the apex. Transmembrane voltage was recorded with optical mapping technique for 16 seconds at a sampling rate of 2ms/frame. We crushed the sinoatrial node to reduce the heart rate. The baseline activation appeared to have endocardial origins with a mean escape ventricular rate of 60 +/- 5bpm at baseline. The DC field (30mA-60mA) alone increased the mean heart rate to 120+/-5bpm. Although DC alone terminated VF in a few cases, the rate of termination was very low (6.2%). However, when pacing+DC was applied, it was possible to terminate VF in 34 of 130 episodes in six rabbits. The rate of successful defibrillation of VF with pacing+DC was significantly higher than that with DC alone (20% vs 6.2%, p<0.01). Pacing alone never terminated the VF. In conclusion, DC field may affect the conduction velocity in normal condition. Pacing+DC intervention could lead to regularization of VF propagation and eventually to termination. Further improvement of this approach may offer a higher success rate of defibrillation with lower energy requirements.

  16. Pregnancy course and outcomes in women with arrhythmogenic right ventricular cardiomyopathy

    PubMed Central

    Hodes, Anke R; Tichnell, Crystal; te Riele, Anneline S J M; Murray, Brittney; Groeneweg, Judith A; Sawant, Abhishek C; Russell, Stuart D; van Spaendonck-Zwarts, Karin Y; van den Berg, Maarten P; Wilde, Arthur A; Tandri, Harikrishna; Judge, Daniel P; Hauer, Richard N W; Calkins, Hugh; van Tintelen, J Peter; James, Cynthia A

    2016-01-01

    Objectives To characterise pregnancy course and outcomes in women with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Methods From a combined Johns Hopkins/Dutch ARVD/C registry, we identified 26 women affected with ARVD/C (by 2010 Task Force Criteria) during 39 singleton pregnancies >13 weeks (1–4 per woman). Cardiac symptoms, treatment and episodes of sustained ventricular arrhythmias (VAs) and heart failure (HF) ≥ Class C were characterised. Obstetric outcomes were ascertained. Incidence of VA and HF were compared with rates in the non-pregnant state. Long-term disease course was compared with 117 childbearing-aged female patients with ARVD/C who had not experienced pregnancy with ARVD/C. Results Treatment during pregnancy (n=39) included β blockers (n=16), antiarrhythmics (n=6), diuretics (n=3) and implantable cardioverter defibrillators (ICDs) (n=28). In five pregnancies (13%), a single VA occurred, including two ICD-terminated events. Arrhythmias occurred disproportionately in probands without VA history (p=0.045). HF, managed on an outpatient basis, developed in two pregnancies (5%) in women with pre-existing overt biventricular or isolated right ventricular disease. All infants were live-born without major obstetric complications. Caesarean sections (n=11, 28%) had obstetric indications, except one (HF). β Blocker therapy was associated with lower birth weight (3.1±0.48 kg vs 3.7±0.57 kg; p=0.002). During follow-up children remained healthy (median 3.4 years), and mothers were without cardiac mortality or transplant. Neither VA nor HF incidence was significantly increased during pregnancy. ARVD/C course (mean 6.5±5.6 years) did not differ based on pregnancy history. Conclusions While most pregnancies in patients with ARVD/C were tolerated well, 13% were complicated by VA and 5% by HF. PMID:26719359

  17. STIM1 enhances SR Ca2+ content through binding phospholamban in rat ventricular myocytes

    PubMed Central

    Zhao, Guiling; Li, Tianyu; Brochet, Didier X. P.; Rosenberg, Paul B.; Lederer, W. J.

    2015-01-01

    In ventricular myocytes, the physiological function of stromal interaction molecule 1 (STIM1), an endo/sarcoplasmic reticulum (ER/SR) Ca2+ sensor, is unclear with respect to its cellular localization, its Ca2+-dependent mobilization, and its action on Ca2+ signaling. Confocal microscopy was used to measure Ca2+ signaling and to track the cellular movement of STIM1 with mCherry and immunofluorescence in freshly isolated adult rat ventricular myocytes and those in short-term primary culture. We found that endogenous STIM1 was expressed at low but measureable levels along the Z-disk, in a pattern of puncta and linear segments consistent with the STIM1 localizing to the junctional SR (jSR). Depleting SR Ca2+ using thapsigargin (2–10 µM) changed neither the STIM1 distribution pattern nor its mobilization rate, evaluated by diffusion coefficient measurements using fluorescence recovery after photobleaching. Two-dimensional blue native polyacrylamide gel electrophoresis and coimmunoprecipitation showed that STIM1 in the heart exists mainly as a large protein complex, possibly a multimer, which is not altered by SR Ca2+ depletion. Additionally, we found no store-operated Ca2+ entry in control or STIM1 overexpressing ventricular myocytes. Nevertheless, STIM1 overexpressing cells show increased SR Ca2+ content and increased SR Ca2+ leak. These changes in Ca2+ signaling in the SR appear to be due to STIM1 binding to phospholamban and thereby indirectly activating SERCA2a (Sarco/endoplasmic reticulum Ca2+ ATPase). We conclude that STIM1 binding to phospholamban contributes to the regulation of SERCA2a activity in the steady state and rate of SR Ca2+ leak and that these actions are independent of store-operated Ca2+ entry, a process that is absent in normal heart cells. PMID:26261328

  18. Reduced Right Ventricular Function Predicts Long-Term Cardiac Re-Hospitalization after Cardiac Surgery

    PubMed Central

    Goldsmith, Yulia; Chan, Jacqueline; Iskandir, Marina; Gulkarov, Iosif; Tortolani, Anthony; Brener, Sorin J.; Sacchi, Terrence J.; Heitner, John F.

    2015-01-01

    Background The significance of right ventricular ejection fraction (RVEF), independent of left ventricular ejection fraction (LVEF), following isolated coronary artery bypass grafting (CABG) and valve procedures remains unknown. The aim of this study is to examine the significance of abnormal RVEF by cardiac magnetic resonance (CMR), independent of LVEF in predicting outcomes of patients undergoing isolated CABG and valve surgery. Methods From 2007 to 2009, 109 consecutive patients (mean age, 66 years; 38% female) were referred for pre-operative CMR. Abnormal RVEF and LVEF were considered <35% and <45%, respectively. Elective primary procedures include CABG (56%) and valve (44%). Thirty-day outcomes were perioperative complications, length of stay, cardiac re-hospitalizations and early mortaility; long-term (> 30 days) outcomes included, cardiac re-hospitalization, worsening congestive heart failure and mortality. Mean clinical follow up was 14 months. Findings Forty-eight patients had reduced RVEF (mean 25%) and 61 patients had normal RVEF (mean 50%) (p<0.001). Fifty-four patients had reduced LVEF (mean 30%) and 55 patients had normal LVEF (mean 59%) (p<0.001). Patients with reduced RVEF had a higher incidence of long-term cardiac re-hospitalization vs. patients with normal RVEF (31% vs.13%, p<0.05). Abnormal RVEF was a predictor for long-term cardiac re-hospitalization (HR 3.01 [CI 1.5-7.9], p<0.03). Reduced LVEF did not influence long-term cardiac re-hospitalization. Conclusion Abnormal RVEF is a stronger predictor for long-term cardiac re-hospitalization than abnormal LVEF in patients undergoing isolated CABG and valve procedures. PMID:26197273

  19. The earliest published electrocardiogram showing ventricular preexcitation.

    PubMed

    Von Knorre, Georg H

    2005-03-01

    When in 1930, Wolff, Parkinson, and White published what is today known as the WPW, or preexcitation syndrome, they, and subsequently others, found few comparable cases in the preceding literature. Among these the report of Cohn and Fraser, published in 1913, was the earliest. However, another even earlier documentation in a 1909 article by Hoffmann escaped notice till now. The ECG of a patient with paroxysmal tachycardia reveals a short PR interval and a delta-wave-induced widening of the QRS complex, even though the reproduced tachycardia was not preexcitation related. The interpretation of this poorly reproduced ECG can be confirmed by another and more detailed description of the patient in an electrocardiography textbook published in 1914 by the same author. Thus, the earliest publication of an ECG showing ventricular preexcitation now can be dated back to 1909. Moreover, the Hoffmann monograph contains two additional examples of the WPW syndrome not noticed until now. All three cases published by Hoffmann had their first ECG recordings in 1912 or earlier. PMID:15733183

  20. Loperamide Induced Life Threatening Ventricular Arrhythmia

    PubMed Central

    Bodar, Vijaykumar; Singh, Sharanjit; Frumkin, William; Mangla, Aditya; Doshi, Kaushik

    2016-01-01

    Loperamide is over-the-counter antidiarrheal agent acting on peripherally located μ opioid receptors. It is gaining popularity among drug abusers as opioid substitute. We report a case of a 46-year-old male that was presented after cardiac arrest. After ruling out ischemia, cardiomyopathy, pulmonary embolism, central nervous system pathology, sepsis, and other drug toxicity, we found out that patient was using around 100 mg of Loperamide to control his chronic diarrhea presumably because of irritable bowel syndrome for last five years and consumed up to 200 mg of Loperamide daily for last two days before the cardiac arrest. We hypothesize that the patient's QTc prolongation and subsequent cardiac arrest are due to Loperamide toxicity. Patient experienced gradual resolution of tachyarrhythmia and gradual decrease in QTc interval during hospitalization which supports the evidence of causal relationship between Loperamide overdose and potentially fatal arrhythmias. It also provided the clue that patient may have congenital long QT syndrome which was unmasked by Loperamide causing ventricular arrhythmias. This case adds one more pearl in the literature to support that Loperamide overdose related cardiac toxicity does exist and it raises concerns over Loperamide abuse in the community. PMID:27547470

  1. Newer-generation ventricular assist devices.

    PubMed

    Agarwal, Shvetank; High, Kane M

    2012-06-01

    The latest generation of ventricular assist devices has evolved from the pulsatile, volume-displacement pumps of the 1990s to today's non-pulsatile, constant pressure-generating rotary pumps. These pumps include both centrifugal and axial flow devices that are currently being used or are in advanced development. Rotary pumps have the advantage of a much longer and more reliable duty life than pulsatile pumps. They are also considerably smaller than pulsatile pumps, requiring less invasive surgery for implantation and smaller transcutaneous (electrical rather than pneumatic) drivelines. Most of these devices have been approved as a bridge to transplant (BTT) while some are currently in trials for destination therapy (DT) in Europe (Conformité Européenne (CE) mark) or the United States (Food and Drug Administration (FDA)). This article discusses the current generation of pumps, examining particular design features as highlighted by the designers as well as the current approval status of each device in the United States and Europe. PMID:22910085

  2. Urgent operation for acquired ventricular septal defect.

    PubMed Central

    Thomas, C S; Alford, W C; Burrus, G R; Glassford, D M; Stoney, W S

    1982-01-01

    Recent experience suggests that ventricular septal defect (VSD) secondary to myocardial infarction constitutes an indication for urgent operation. Acquired VSD at St. Thomas Hospital, Nashville, was reviewed to substantiate the obsolescence of protracted medical therapy designed to allow a late, technically less demanding, repair. Twenty-two acute VSDs (less than four weeks following onset of murmur) have been treated since 1970. Five patients died during medical therapy. Two patients survived for more than four weeks without operation. One never manifested significant cardiac decompensation. The other was operated on at 33 days, after progressive deterioration. No technical advantage from the delay was apparent, although survival was achieved. Ten of 15 patients (67%) operated on during the first four weeks survived. Fourteen had reached a level of marked instability prior to operation. Of the five deaths, four were technical and were the product of an initial lack of recognition of the necessity for patch replacement of the interventricular septum. The prosthetic patch is now considered essential to minimize suture-line stress in necrotic muscle. Potentially, only one of 15 patients operated on early using current methods would have expired. This experience supports an aggressive surgical approach to any unstable patient with postinfarction VSD. Early repair requires specific techniques. Results of early operation using these techniques are dramatically superior to past efforts designed to delay definitive repair. PMID:7082062

  3. Loperamide Induced Life Threatening Ventricular Arrhythmia.

    PubMed

    Upadhyay, Ankit; Bodar, Vijaykumar; Malekzadegan, Mohammad; Singh, Sharanjit; Frumkin, William; Mangla, Aditya; Doshi, Kaushik

    2016-01-01

    Loperamide is over-the-counter antidiarrheal agent acting on peripherally located μ opioid receptors. It is gaining popularity among drug abusers as opioid substitute. We report a case of a 46-year-old male that was presented after cardiac arrest. After ruling out ischemia, cardiomyopathy, pulmonary embolism, central nervous system pathology, sepsis, and other drug toxicity, we found out that patient was using around 100 mg of Loperamide to control his chronic diarrhea presumably because of irritable bowel syndrome for last five years and consumed up to 200 mg of Loperamide daily for last two days before the cardiac arrest. We hypothesize that the patient's QTc prolongation and subsequent cardiac arrest are due to Loperamide toxicity. Patient experienced gradual resolution of tachyarrhythmia and gradual decrease in QTc interval during hospitalization which supports the evidence of causal relationship between Loperamide overdose and potentially fatal arrhythmias. It also provided the clue that patient may have congenital long QT syndrome which was unmasked by Loperamide causing ventricular arrhythmias. This case adds one more pearl in the literature to support that Loperamide overdose related cardiac toxicity does exist and it raises concerns over Loperamide abuse in the community. PMID:27547470

  4. Abnormal subendocardial function in restrictive left ventricular disease.

    PubMed Central

    Henein, M Y; Gibson, D G

    1994-01-01

    OBJECTIVE--To study possible disturbances in left ventricular long axis function in patients with a restrictive filling pattern. DESIGN--Prospective examination of the left ventricular transverse and longitudinal axes, transmitral flow, and the apexcardiogram. SETTING--A tertiary referral centre for cardiac diseases. SUBJECTS--21 normal subjects, age (SD) 51(11); 30 patients of similar age with a restrictive left ventricular filling pattern, defined as short early diastolic deceleration time less than the lower 95% confidence limit of the normal value (120 ms). 20 patients had a normal and 10 had an increased left ventricular end diastolic cavity size. RESULTS--Mitral Doppler echocardiography: E wave velocity was high only in patients with a normal cavity size. A wave velocity was greatly reduced in the two groups (P < 0.001) so that the E/A ratio was abnormally high. The relative A wave amplitude on the apexcardiogram was greatly increased in the two groups: 46(15)% (mean (SD)) and 54(4)% v 15(5)%. Minor axis: Fractional shortening was reduced from 30(10)% to 17(7)% in patients with normal cavity size and to 13(4.2)% in those with a dilated cavity (P < 0.001), as was the posterior wall thickening fraction from 100(30)% to 42(20)% and 50(25)% respectively (P < 0.001). Total systolic epicardial motion was normal and isovolumic relaxation time was short in the two groups. Long axis: Left ventricular abnormalities included reduced total amplitude of motion and its component during atrial systole (P < 0.001 for the two groups at both sites). Peak long axis shortening and lengthening were decreased at both left ventricular sites (P < 0.001). The time intervals from q wave of the electrocardiogram and A2 (aortic valve closure) to the onset of shortening and lengthening respectively were increased (both P < 0.001). Right ventricular long axis function was similarly affected but to a lesser extent. CONCLUSION--Left ventricular long axis function is consistently abnormal in

  5. A Striking Coronary Artery Pattern in a Grown-Up Congenital Heart Disease Patient

    PubMed Central

    Iacovelli, Fortunato; Pepe, Martino; Contegiacomo, Gaetano; Alberotanza, Vito; Masi, Filippo; Bortone, Alessandro Santo; Favale, Stefano

    2016-01-01

    Left ventricular noncompaction (LVNC) is a myocardial disorder probably due to the arrest of normal embryogenesis of the left ventricle. It could be isolated or associated with other extracardiac and cardiac abnormalities, including coronary artery anomalies. Despite the continuous improvement of imaging resolution quality, this cardiomyopathy still remains frequently misdiagnosed, especially if associated with other heart diseases. We report a case of LVNC association with both malposition of the great arteries and a very original coronary artery pattern. PMID:26881144

  6. The relationship between ventricular electrical delay and left ventricular remodelling with cardiac resynchronization therapy

    PubMed Central

    Gold, Michael R.; Birgersdotter-Green, Ulrika; Singh, Jagmeet P.; Ellenbogen, Kenneth A.; Yu, Yinghong; Meyer, Timothy E.; Seth, Milan; Tchou, Patrick J.

    2011-01-01

    Aims The aim of the present study was to evaluate the relationship between left ventricular (LV) electrical delay, as measured by the QLV interval, and outcomes in a prospectively designed substudy of the SMART-AV Trial. Methods and results This was a multicentre study of patients with advanced heart failure undergoing cardiac resynchronization therapy (CRT) defibrillator implantation. In 426 subjects, QLV was measured as the interval from the onset of the QRS from the surface ECG to the first large peak of the LV electrogram. Left ventricular volumes were measured by echocardiography at baseline and after 6 months of CRT by a blinded core laboratory. Quality of life (QOL) was assessed by a standardized questionnaire. When separated by quartiles based on QLV duration, reverse remodelling response rates (>15% reduction in LV end systolic volume) increased progressively from 38.7 to 68.4% and QOL response rate (>10 points reduction) increased from 50 to 72%. Patients in the highest quartile of QLV had a 3.21-fold increase (1.58–6.50, P = 0.001) in their odds of a reverse remodelling response after correcting for QRS duration, bundle branch block type, and clinical characteristics by multivariate logistic regression analysis. Conclusion Electrical dyssynchrony, as measured by QLV, was strongly and independently associated with reverse remodelling and QOL with CRT. Acute measurements of QLV may be useful to guide LV lead placement. PMID:21875862

  7. Dysplastic conditions of the right ventricular myocardium: Uhl's anomaly vs arrhythmogenic right ventricular dysplasia.

    PubMed Central

    Gerlis, L M; Schmidt-Ott, S C; Ho, S Y; Anderson, R H

    1993-01-01

    OBJECTIVE--Since 1905 there have been many reports of cases in which the right ventricle was deficient in myocardium. Several terms have been used to describe this condition. Of these, "Uhl's anomaly" and "arrhythmogenic right ventricular dysplasia" are most often used. Our study investigates the relation between these entities. METHOD--Five cases with a primary deficiency of the right ventricular musculature were examined. The findings were compared with those published reports to evaluate the similarities and differences between Uhl's anomaly and arrhythmogenic dysplasia. RESULTS--The five cases showed two patterns of myocardial deficiency in the right ventricle. On the one hand, the parietal wall was paper thin with complete absence of musculature and apposition of the endocardial and epicardial layers. On the other hand, patchy, localised fibrofatty tissue replacement was found within the parietal musculature. Evidence from our cases, combined with analysis of other publications, showed different modes and timing of clinical presentation of the patients with these two anatomical conditions, congestive heart failure or arrhythmia. CONCLUSIONS--The conditions variously described as Uhl's anomaly and arrhythmogenic dysplasia are separate and distinct morphological entities. Images PMID:8435240

  8. Left ventricular systolic response to exercise in patients with systemic hypertension without left ventricular hypertrophy.

    PubMed

    Christian, T F; Zinsmeister, A R; Miller, T D; Clements, I P; Gibbons, R J

    1990-05-15

    Supine exercise radionuclide angiography was performed in 367 men to assess left ventricular (LV) systolic response to exercise; 58 had systemic hypertension without LV hypertrophy on a resting electrocardiogram and 309 were normotensive. All patients met the following criteria defining a low pretest likelihood of coronary artery disease: age less than 50 years; normal electrocardiographic response to exercise; absence of typical or atypical chest pain; and exercise heart rate greater than 120 beats/min. Patients taking beta-receptor blockers were excluded. There were no significant differences between hypertensive and normotensive groups in peak exercise heart rate, workload or exercise duration. However, hypertensive patients had significantly higher peak exercise systolic blood pressures and peak exercise rate-pressure products. There were no differences between patients with and without hypertension in resting ejection fraction, peak exercise ejection fraction (hypertensive patients 0.71 +/- 0.01, normotensive patients 0.70 +/- 0.05) or change in ejection fraction at peak exercise (hypertensive patients 0.07 +/- 0.01, normotensive patients 0.07 +/- 0.04). Diastolic and systolic ventricular volumes tended to be smaller in the hypertensive patients, but the difference was not statistically significant. The change in systolic volume with exercise was similar in the 2 groups (hypertensive -10 +/- 3 ml/m2, normotensive -10 +/- 1 ml/m2). In the absence of electrocardiographic evidence of LV hypertrophy, systemic hypertension does not influence LV systolic response to exercise. PMID:2140008

  9. Effect of Continued Cardiac Resynchronization Therapy on Ventricular Arrhythmias After Left Ventricular Assist Device Implantation.

    PubMed

    Schleifer, John William; Mookadam, Farouk; Kransdorf, Evan P; Nanda, Udai; Adams, Jonathon C; Cha, Stephen; Pajaro, Octavio E; Steidley, David Eric; Scott, Robert L; Carvajal, Tomas; Saadiq, Rayya A; Srivathsan, Komandoor

    2016-08-15

    Cardiac resynchronization therapy (CRT) reduces ventricular arrhythmia (VA) burden in some patients with heart failure, but its effect after left ventricular assist device (LVAD) implantation is unknown. We compared VA burden in patients with CRT devices in situ who underwent LVAD implantation and continued CRT (n = 39) to those who had CRT turned off before discharge (n = 26). Implantable cardioverter-defibrillator (ICD) shocks were significantly reduced in patients with continued CRT (1.5 ± 2.7 shocks per patient vs 5.5 ± 9.3 with CRT off, p = 0.014). There was a nonsignificant reduction in cumulative VA episodes per patient with CRT continued at discharge (42 ± 105 VA per patient vs 82 ± 198 with CRT off, p = 0.29). On-treatment analysis by whether CRT was on or off identified a significantly lower burden of VA (17 ± 1 per patient-year CRT on vs 37 ± 1 per patient-year CRT off, p <0.0001) and ICD shocks (1.2 ± 0.3 per patient-year CRT on vs 1.7 ± 0.3 per patient-year CRT off, p = 0.018). In conclusion, continued CRT is associated with significantly reduced ICD shocks and VA burden after LVAD implantation. PMID:27328958

  10. A gastroesophageal electrode for atrial and ventricular pacing.

    PubMed

    McEneaney, D J; Cochrane, D J; Anderson, J A; Adgey, A A

    1997-07-01

    Temporary transvenous cardiac pacing requires technical expertise and access to fluoroscopy. We have developed a gastroesophageal electrode capable of atrial and ventricular pacing. The flexible polythene gastroesophageal electrode is passed into the stomach under light sedation. Five ring electrodes, now positioned in the lower esophagus, are used for atrial pacing. A point source (cathode) on the distal tip of the electrode, now positioned in the gastric fundus, is used for ventricular pacing. Two configurations of atrial and ventricular pacing were compared: unipolar and bipolar. During unipolar ventricular pacing the indifferent electrode (anode) was a high impedance chest pad. For bipolar ventricular pacing the indifferent electrode was a ring electrodes placed 2 cm proximal to the tip. Unipolar atrial pacing was performed with 1 of 5 proximal ring electrodes acting as cathode ("cathodic") or as anode ("anodic") in conjunction with a chest pad. Bipolar atrial pacing was performed using combinations of 2 of 5 ring electrodes. Atrial capture was obtained in all 55 subjects attempted. When all electrode combinations were compared, atrial capture was significantly more frequent using the bipolar approach (153/210 bipolar, 65/210 unipolar; t = 7.37, P < 0.001). For unipolar atrial pacing, cathodic stimulation (from esophagus) was more successful than anodic stimulation (cathodic 62/105, anodic 20/105; t = 5.81, P < 0.001). In 43 subjects attempted unipolar ventricular pacing resulted in a higher frequency of capture than the bipolar approach (unipolar 41/43 (95.3%), bipolar 19/43 (44.2%); P < 0.001). In conclusion, atrial pacing was optimal using pairs of ring electrodes ("bipolar") while ventricular pacing was optimal using the distal electrode tip (cathode) in conjunction with a chest pad electrode ("unipolar"). This gastroesophageal electrode may be useful in the emergency management of acute bradyarrhythmias and for elective electrophysiological studies. PMID

  11. The incidence and morphology of ischaemic ventricular tachycardia.

    PubMed

    Quyyumi, A A; Crake, T; Wright, C; Mockus, L; Levy, R D; Fox, K M

    1986-12-01

    Ventricular arrhythmias are a frequent cause of sudden death in patients with coronary artery disease. The incidence and relationship of ventricular tachycardia to periods of myocardial ischaemia in these patients has not been fully investigated. Ambulatory ST-segment monitoring was performed in 100 consecutive patients with chest pain, of whom 74 had significant coronary artery disease. Recordings were analysed for ST-segment changes and episodes of ventricular tachycardia (greater than 3 beats, rate greater than 100 beats min-1). None of the 26 patients with normal coronary arteries, one of the 22 patients (4.5%) with single vessel disease, one of the 22 patients (4.5%) with double vessel disease and four of the 30 patients (13%) with triple vessel disease, had episodes of non-sustained ventricular tachycardia. Four of these six patients had episodes of reversible ST-segment change but ventricular tachycardia was related to these episodes in only two patients. These two patients had multiple episodes of tachycardia which occurred after the onset of ST-segment change and terminated before the ST-segment returned to baseline; they occurred in clusters with a mean of 12 episodes in each cluster. ST-segment change did not follow episodes of ventricular tachycardia in any patient. The number of ventricular complexes in each episode varied between three and 24 beats and were uniform in three of the six patients. The mean heart rate before the onset of tachycardia was 79 +/- 8 beats per minute and the rate of tachycardia had a mean of 170 +/- 34 beats a minute. Less than 10% of the episodes had a prematurity index of less than 1.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2435552

  12. Early repolarization as a predictor of premature ventricular beats.

    PubMed

    Matoshvili, Z T; Petriashvili, Sh G; Archadze, A T; Azaladze, I G

    2015-02-01

    Early repolarization pattern (ERP) is a common ECG variant, characterized by J point elevation manifested either as terminal QRS slurring (the transition from the QRS segment to the ST segment) or notching (a positive deflection inscribed on terminal QRS complex) associated with concave upward ST-segment elevation and prominent T waves in at least two contiguous leads. Aim of this observational study was to compare number of premature ventricular beats in the different groups of patients with early repolarization. The result of this observational study shows that there are: 1,74 fold higher number of premature ventricular beats in 41-74 year subgroup VS 19-40 year subgroup; 1,31 fold higher number of premature ventricular beats in male subgroup VS female subgroup (But this difference is not statistically significant, because t=1,49, p=0,141); 2,85 fold higher number of premature ventricular beats in CAD+ERP subgroup VS ERP without CAD subgroup; 1,74 fold higher number of premature ventricular beats in HF+ERP subgroup VS ERP without HF subgroup; 1,81 fold higher number of premature ventricular beats in CAD+ERP subgroup VS CAD without ERP subgroup; 1,58 fold higher number of premature ventricular beats in HF+ERP subgroup VS HF without ERP subgroup; So, CAD+ERP is very arrhythmogenic condition, after this is HF+ERP, Then Age. This study shows that ERP independently increase number of PVB in different groups (CAD, HF). This is principally new and very important result. Also the number of patients is enough to make this conclusion. PMID:25802448

  13. Mapping of Regional Myocardial Strain and Work During Ventricular Pacing

    PubMed Central

    Prinzen, Frits W.; Hunter, William C.; Wyman, Bradley T.; McVeigh, Elliot R.

    2007-01-01

    OBJECTIVES The purpose of this study was to determine the spatial distribution of myocardial function (myofiber shortening and work) within the left ventricular (LV) wall during ventricular pacing. BACKGROUND Asynchronous electrical activation, as induced by ventricular pacing, causes various abnormalities in LV function, perfusion and structure. These derangements may be caused by abnormalities in regional contraction patterns. However, insight into these patterns during pacing is as yet limited. METHODS In seven anesthetized dogs, high spatial and temporal resolution magnetic resonance-tagged images were acquired in three orthogonal planes. Three-dimensional deformation data and LV cavity pressure and volume were used to determine midwall circumferential strain and external and total mechanical work at 192 sites around the left ventricle. RESULTS During ventricular pacing, systolic fiber strain and external work were approximately zero in regions near the pacing site, and gradually increased to more than twice the normal value in the most remote regions. Total mechanical work, normalized to the value during right atrial pacing, was 38 ± 13% (right ventricular apex [RVapex] pacing) and 61 ± 23% (left ventricular base [LVbase] pacing) close to the pacing site, and 125 ± 48% and 171 ± 60% in remote regions, respectively (p < 0.05 between RVapex and LVbase pacing). The number of regions with reduced work was significantly larger during RVapex than during LVbase pacing. This was associated with a reduction of global LV pump function during RVapex pacing. CONCLUSIONS Ventricular pacing causes a threefold difference in myofiber work within the LV wall. This difference appears large enough to regard local myocardial function as an important determinant for abnormalities in perfusion, metabolism, structure and pump function during asynchronous electrical activation. Pacing at sites that cause more synchronous activation may limit the occurrence of such derangements

  14. Surgical considerations for the explantation of the Parachute left ventricular partitioning device and the implantation of the HeartMate II left ventricular assist device

    PubMed Central

    Bansal, Shelley; Rosas, Paola C.; Mazzaferri, Ernest L.; Sai-Sudhakar, Chittoor B.

    2016-01-01

    Chronic heart failure is the leading cause of death in the world. With newer therapies, the burden of this disease has decreased; however, a significant number of patients remain refractive to existing therapies. Myocardial infarction often leads to ventricular remodeling and eventually contributes to heart failure. The Parachute™ (Cardiokinetix, Menlo Park, CA) is the first device designed for percutaneous ventricular restoration therapy, which reduces left ventricular volume and minimizes the risk of open surgical procedures. For the first time, we report a case of explantation of the Parachute ventricular partitioning device and transition to a HeartMate II™ left ventricular assist device and the surgical considerations for a successful outcome. PMID:27034560

  15. Surgical considerations for the explantation of the Parachute left ventricular partitioning device and the implantation of the HeartMate II left ventricular assist device.

    PubMed

    Ravi, Yazhini; Bansal, Shelley; Rosas, Paola C; Mazzaferri, Ernest L; Sai-Sudhakar, Chittoor B

    2016-04-01

    Chronic heart failure is the leading cause of death in the world. With newer therapies, the burden of this disease has decreased; however, a significant number of patients remain refractive to existing therapies. Myocardial infarction often leads to ventricular remodeling and eventually contributes to heart failure. The Parachute™ (Cardiokinetix, Menlo Park, CA) is the first device designed for percutaneous ventricular restoration therapy, which reduces left ventricular volume and minimizes the risk of open surgical procedures. For the first time, we report a case of explantation of the Parachute ventricular partitioning device and transition to a HeartMate II™ left ventricular assist device and the surgical considerations for a successful outcome. PMID:27034560

  16. [Hypothermia induced alteration of refractoriness in the ventricular myocardium of ground souirrel Citellus undulatus].

    PubMed

    Kuz'min, V S; Abramov, A A; Egorov, Iu V; Rozenshtraukh, L V

    2014-12-01

    Bioelectrical activity and refractoriness in ventricular myocardium of the hibernator--ground squirrel Citellus undulatus were investigated during hypothermia. Experiments were performed with use of isolated, perfused preparations of papillary muscle from right ventricular. Preparations were obtained from hibernating (HS), summer active (SAS) squirrels and from rats. Bioelectrical activity was registered using the standard microelectrode technique at 37-17 degrees C. Action potentials duration (APD), refractoriness duration (RD) and the velocity of the action potential wave front (dV/dt) were estimated. Hypothermia induced APD and RD prolongation were demonstrated in all groups of experimental animals. However, normalized RD was significantly longer in the HS group during hypothermia than in SAS and rats. Ratio of RD to APD in HS group exceeds unity at 17 degrees C, which allows to suggest so called "postrepolarization refractoriness" during hypothermia. Also, HS reveal more prominent preservation of dV/dt during hypothermia than SAS and rat. Significant prolongation of RD and maintenance of normal excitation conduction during hypothermia probably plays essential role in hibernators resistivity to cold induced arrhythmias. PMID:25936179

  17. A two-phase fluid volume compensation chamber for an electric ventricular assist device.

    PubMed

    Lamson, T C; Ojan, O S; Geselowitz, D B; Tarbell, J M

    1990-08-01

    A volume compensation chamber is a device used to reduce large pressure fluctuations created in electric ventricular assist devices during the emptying and filling of the blood sac. In this study, the effect of motor casing pressure variation (pressure swing) on the performance of the Penn State electric ventricular assist device (EVAD) was investigated. Design criteria were established for the maximum pressure swing tolerated by the EVAD and the optimal mean chamber pressure at which to operate. At the chosen mean chamber pressure of -15 mm Hg, it was found that pressure swing should be maintained below 45 mm Hg. A two-phase fluid volume compensation chamber was developed that reduced the pressure swing enough to ensure adequate pump performance. The device consists of a metal chamber with a high-heat-flux porous coating applied to the inside surface. The chamber uses Freon as the working fluid and is isolated from the EVAD by a metal bellows. It was found that the high-flux coating significantly reduces the pressure swing, in some cases by as much as 50% when compared with an identical chamber with no coating. In the coated chamber the pressure swing was maintained between 22 and 30 mm Hg at a beat rate of 60 beats/min, for a wide range of Freon volumes (4-38 ml). Even at 100 beats/min the pressure swings obtained with the coated chamber are well within an acceptable range. PMID:2396924

  18. [Atrioventricular crosstalk with unipolar leads: a cause of ventricular asystole and syncope].

    PubMed

    Amara, W

    2013-11-01

    In this article, we describe a case of ventricular asystole in a patient implanted with a cardiac pacemaker. The patient had a device replacement. The new pacemaker has been connected to old unipolar leads. The detection has been, inadvertently, programmed in a bipolar mode. This programmation induced an inhibition of the atrial and ventricular pacing due to oversensing of myopotentials. An inhibition of ventricular stimulation has been recorded also because of ventricular detection of the unipolar atrial stimulation (atrioventricular crosstalk). Lack of ventricular stimulation induced in this dependant patient ventricular asystole and syncope. PMID:24055198

  19. An appreciation of some timing functions of a cardiac resynchronization device capable of left ventricular sensing.

    PubMed

    Barold, S Serge; Kucher, Andreas

    2016-09-01

    Some systems for cardiac resynchronization therapy (CRT) offer left ventricular sensing. This discussion with an illustrative case demonstrates that timing cycles in these devices may sometimes be difficult to understand because of left ventricular sensing. Programming of the left ventricular upper rate interval is crucial to optimize the resynchronization ability of the system. Interactions with the maximum sensor rate, the right ventricular upper rate interval, the left ventricular T wave protection algorithm, and the minimum ventricular tachycardia detection rate have to be considered. PMID:27605233

  20. Transition from ventricular fibrillation to ventricular tachycardia: a simulation study on the role of Ca(2+)-channel blockers in human ventricular tissue.

    PubMed

    Bernus, O; Van Eyck, B; Verschelde, H; Panfilov, A V

    2002-12-01

    We study the effect of blocking the L-type Ca(2+)-channel on fibrillation in simulations in two-dimensional (2D) isotropic sheets of ventricular tissue and in a three-dimensional anisotropic anatomical model of human ventricles, using a previously developed model of human ventricular cells. Ventricular fibrillation (VF) was obtained as a result of spiral wave breakup and consisted of a varying number of chaotically wandering wavelets activating tissue at a frequency of about 6.0 Hz. We show that blocking the Ca(2+)-current by 75% can convert ventricular fibrillation into a periodic regime with a small number of stable spiral waves, ranging from six in 2D sheets of 25 x 25 cm to a single spiral in the anatomical model of human ventricles. The dominant frequency during this process changed to about 10.0 Hz in the 2D simulations, but to only 5.0 Hz in the whole heart simulations where a single spiral wave anchored around an anatomical obstacle. We show that the observed effects were due to a flattening of the electrical restitution curve, which prevented the generation of wave breaks and stabilized the activation patterns. PMID:12502041

  1. Hemodynamic importance of preserving the normal sequence of ventricular activation in permanent cardiac pacing.

    PubMed

    Leclercq, C; Gras, D; Le Helloco, A; Nicol, L; Mabo, P; Daubert, C

    1995-06-01

    Pacing the right ventricle in the apex profoundly modifies the sequence of activation and thus the sequence of contraction and relaxation of the left ventricle. To evaluate the relative importance of preserving normal ventricular activation sequence and optimal atrioventricular (AV) synchrony in permanent pacing, we compared the effects of three pacing modes: AAI, preserving both normal AV synchrony and normal activation sequence; DDD, with complete ventricular capture that preserves only AV synchrony; and VVI, disrupting both, at rest and during exercise. Hemodynamic and radionuclide studies were performed in 11 patients who had normal intrinsic conduction and who were implanted on a long-term basis with a DDDR pacemaker for isolated sinus node dysfunction. AAI versus DDD and VVI significantly increased cardiac output at rest (6.6 +/- 1.3 L/min vs 6 +/- 0.9 L/min vs 5 +/- 1 L/min; p < 0.01) and during exercise (13.5 +/- 2 L/min vs 12.1 +/- 2.2 L/min vs 14.4 +/- 2.1 L/min; p < 0.01). Pulmonary capillary wedge pressure was lowest with AAI (15.4 +/- 4.5 mm Hg), with an average reduction of 17% compared with DDD (19.6 +/- 5 mm Hg; p < 0.01) and of 30% compared with VVI (25.8 +/- 7 mm Hg; p < 0.01) during exercise. Identical benefits were observed for all other hemodynamic parameters: right atrial pressure, pulmonary artery pressure, left ventricular (LV) stroke work index, and systemic vascular resistances. LV ejection fraction was significantly higher in AAI than in DDD at rest (61% vs 58%, respectively; p < 0.05) and during exercise (65% vs 60%, respectively; p < 0.05). This improvement in LV systolic function resulted principally from the increase in septal ejection fraction. LV filling also was improved in AAI as demonstrated by a significant increase in peak filling rate at rest and during exercise. These data show the importance of preserving, whenever possible, not only normal AV synchrony but also normal ventricular activation sequence in permanent cardiac

  2. Optical Mapping of Ventricular Fibrillation Dynamics.

    PubMed

    Park, Sarah A; Gray, Richard A

    2015-01-01

    There is very limited information regarding the dynamic patterns of the electrical activity during ventricular fibrillation (VF) in humans. Most of the data used to generate and test hypotheses regarding the mechanisms of VF come from animal models and computer simulations and the quantification of VF patterns is non-trivial. Many of the experimental recordings of the dynamic spatial patterns of VF have been obtained from mammals using "optical mapping" or "video imaging" technology in which "phase maps" are derived from high-resolution transmembrane recordings from the heart surface. The surface manifestation of the unstable reentrant waves sustaining VF can be identified as "phase singularities" and their number and location provide one measure of VF complexity. After providing a brief history of optical mapping of VF, we compare and contrast a quantitative analysis of VF patterns from the heart surface for four different animal models, hence providing physiological insight into the variety of VF dynamics among species. We found that in all four animal models the action potential duration restitution slope was actually negative during VF and that the spatial dispersion of electrophysiological parameters were not different during the first second of VF compared to pacing immediately before VF initiation. Surprisingly, our results suggest that APD restitution and spatial dispersion may not be essential causes of VF dynamics. Analyses of electrophysiological quantities in the four animal models are consistent with the idea that VF is essentially a two-dimensional phenomenon in small rabbit hearts whose size are near the boundary of the "critical mass" required to sustain VF, while VF in large pig hearts is three-dimensional and exhibits the maximal theoretical phase singularity density, and thus will not terminate spontaneously. PMID:26238059

  3. Allometry of left ventricular myocardial innervation.

    PubMed

    Schipke, Julia; Mayhew, Terry M; Mühlfeld, Christian

    2014-04-01

    Body mass (BM) of terrestrial mammalian species ranges from a few grams in the case of the Etruscan shrew to a few tonnes for an elephant. The mass-specific metabolic rate, as well as heart rate, decrease with increasing BM, whereas heart mass is proportional to BM. In the present study, we investigated the scaling behaviour of several compartments of the left ventricular myocardium, notably its innervation, capillaries and cardiomyocytes. Myocardial samples were taken from 10 mammalian species with BM between approximately 2 g and 900 kg. Samples were analysed by design-based stereology and electron microscopy and the resulting data were subjected to linear regression and correlation analyses. The total length of nerve fibres (axons) in the left ventricle increased from 0.017 km (0.020 km) in the shrew to 7237 km (13,938 km) in the horse. The innervation density was similar among species but the mean number of axons per nerve fibre profile increased with rising BM. The total length of capillaries increased from 0.119 km (shrew) to 10,897 km (horse). The volume of cardiomyocytes was 0.017 cm(3) in the shrew and 1818 cm(3) in the horse. Scaling of the data against BM indicated a higher degree of complexity of the axon tree in larger animals and an allometric relationship between total length of nerve fibres/axons and BM. In contrast, the density of nerve fibres is independent of BM. It seems that the structural components of the autonomic nervous system in the heart are related to BM and heart mass rather than to functional parameters such as metabolic rate. PMID:24325466

  4. Right Ventricular Tissue Doppler in Space Flight

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas R.; Barratt, Michael R.; Sargsyan, Ashot E.; Ebert, Douglas; Garcia, Kathleen M.; Martin, David S.; Dulchavsky, Scott A.; Duncan, J. Michael

    2009-01-01

    Tissue Doppler (TD) registers movement of a given sample of cardiac tissue throughout the cardiac cycle. TD spectra of the right ventricle (RV) were obtained from a long-duration ISS crewmember as a portion of an ongoing experiment ("Braslet" test objective). To our knowledge, this is the first report of RV TD conducted in space flight, and the data represent reproducibility and fidelity of this application in space and serve as the first "space normal" data set. Methods RV TD was performed by astronaut scientists remotely guided by an ultrasound expert from Mission Control Center, Houston, TX. In four of the subjects, RV TD was acquired from the free wall near the tricuspid annulus in two separate sessions 4 to 7 days apart. A fifth subject had only one session. All digital DICOM frames were exported for off-line analysis. Systolic (S ), early diastolic (E ) and late diastolic (A ) velocities were measured. RV Tei-index was calculated using diastolic and systolic time intervals as a combined measure of myocardial performance. Results and Discussion The mean values from the first 4 subjects (8 sessions) were used as the on-orbit reference data, and subject 5 was considered as a hypothetical patient for comparison (see Table). The greatest difference was in the early diastolic A (31 %) yet the standard deviation (a) for A amongst the reference subjects was 2.25 (mean = 16.02). Of interest is the Tei index, a simple and feasible indicator of overall ventricular function; it was similar amongst all the subjects. The late diastolic A seems to compensate for the variance in E . Normal Tei index for the RV is < 0.3, yet our data show all but one subject consistently above this level, notwithstanding their nominal responses to daily exercise in microgravity. These data remind us that the physiology of RV preload in altered gravity environments is still not completely understood.

  5. COPD advances in left ventricular diastolic dysfunction

    PubMed Central

    Kubota, Yoshiaki; Asai, Kuniya; Murai, Koji; Tsukada, Yayoi Tetsuou; Hayashi, Hiroki; Saito, Yoshinobu; Azuma, Arata; Gemma, Akihiko; Shimizu, Wataru

    2016-01-01

    Background COPD is concomitantly present in ~30% of patients with heart failure. Here, we investigated the pulmonary function test parameters for left ventricular (LV) diastolic dysfunction and the relationship between pulmonary function and LV diastolic function in patients with COPD. Patients and methods Overall, 822 patients who underwent a pulmonary function test and echocardiography simultaneously between January 2011 and December 2012 were evaluated. Finally, 115 patients with COPD and 115 age- and sex-matched control patients with an LV ejection fraction of ≥50% were enrolled. Results The mean age of the patients was 74.4±10.4 years, and 72.3% were men. No significant differences were found between the two groups regarding comorbidities, such as hypertension, diabetes mellitus, and anemia. The index of LV diastolic function (E/e′) and the proportion of patients with high E/e′ (defined as E/e′ ≥15) were significantly higher in patients with COPD than in control patients (10.5% vs 9.1%, P=0.009; 11.3% vs 4.3%, P=0.046). E/e′ was significantly correlated with the residual volume/total lung capacity ratio. Univariate and multivariate analyses revealed severe COPD (Global Initiative for Chronic Obstructive Lung Disease III or IV) to be a significant predictive factor for high E/e′ (odds ratio [OR] 5.81, 95% confidence interval [CI] 2.13–15.89, P=0.001 and OR 6.00, 95% CI 2.08–17.35, P=0.001, respectively). Conclusion Our data suggest that LV diastolic dysfunction as a complication of COPD may be associated with mechanical exclusion of the heart by pulmonary overinflation. PMID:27099482

  6. Voltage clamp experiments on ventricular myocarial fibres.

    PubMed

    Beeler, G W; Reuter, H

    1970-03-01

    1. A voltage clamp method utilizing a sucrose gap and glass microelectrodes was developed and used to study dog ventricular myocardial fibre bundles. The limitations and the reliability of this method are demonstrated by a series of tests.2. A dynamic sodium current, excited at membrane potentials more positive than -65 mV, was measured. The equilibrium potential for this large, rapid inward current depends directly on [Na](o), shifting 29.0 +/- 2.3 mV (+/- S.E. of mean), as opposed to a theoretically expected value of 30.6 mV, when [Na](o) is reduced to 31% of normal.3. Sodium current is inactivated by conditioning depolarizations. Complete inactivation occurs with conditioning potentials more positive than -45 mV, and 50% inactivation occurs at about -55 mV. The location of the inactivation curve shifts along the voltage axis, when [Ca](o) is varied between 0.2 and 7.2 mM.4. A second, much smaller and slower net inward current, with a threshold around -30 mV, and an equilibrium potential above +40 mV was also observed.5. The ;steady-state' current-voltage relationship (after 300-600 msec) exhibits inward-going (anomalous) rectification with negative slope between -50 and -25 mV.6. A small, very slowly developing component of outward current was observed at inside positive potentials. The equilibrium potential for this current, although slightly dependent on [K](o), is neither identical with the potassium equilibrium potential nor with the resting potential in normal Tyrode solution.7. Anatomical limitations, primarily resistance in the extracellular space within the bundle, prevent complete characterization of the rapid, large sodium current, but do not limit the application of the clamp method to the study of other, smaller and slower currents. The evidence for this is discussed extensively in the Appendix. PMID:5503866

  7. Aspirate from human stented saphenous vein grafts induces epicardial coronary vasoconstriction and impairs perfusion and left ventricular function in rat bioassay hearts with pharmacologically induced endothelial dysfunction.

    PubMed

    Lieder, Helmut R; Baars, Theodor; Kahlert, Philipp; Kleinbongard, Petra

    2016-08-01

    Stent implantation into aortocoronary saphenous vein grafts (SVG) releases particulate debris and soluble vasoactive mediators, for example, serotonin. We now analyzed effects of the soluble mediators released into the coronary arterial blood during stent implantation on vasomotion of isolated rat epicardial coronary artery segments and on coronary flow and left ventricular developed pressure in isolated perfused rat hearts. Coronary blood was retrieved during percutaneous SVG intervention using a distal occlusion/aspiration protection device in nine symptomatic patients with stable angina pectoris and a flow-limiting SVG stenosis. The blood was separated into particulate debris and plasma. Responses to coronary plasma were determined in isolated rat epicardial coronary arteries and in isolated, constant pressure-perfused rat hearts (±nitric oxide synthase [NOS] inhibition and ±serotonin receptor blockade, respectively). Coronary aspirate plasma taken after stent implantation induced a stronger vasoconstriction of rat epicardial coronary arteries (52 ± 8% of maximal potassium chloride induced vasoconstriction [% KClmax = 100%]) than plasma taken before stent implantation (12 ± 8% of KClmax); NOS inhibition augmented this vasoconstrictor response (to 110 ± 15% and 24 ± 9% of KClmax). Coronary aspirate plasma taken after stent implantation reduced in isolated perfused rat hearts only under NOS inhibition coronary flow by 17 ± 3% and left ventricular developed pressure by 25 ± 4%. Blockade of serotonin receptors abrogated these effects. Coronary aspirate plasma taken after stent implantation induces vasoconstriction in isolated rat epicardial coronary arteries and reduces coronary flow and left ventricular developed pressure in isolated perfused rat hearts with pharmacologically induced endothelial dysfunction. PMID:27482071

  8. Hypercholesterolaemia exacerbates ventricular remodelling after myocardial infarction in the rat: role of angiotensin II type 1 receptors

    PubMed Central

    Mączewski, M; Mączewska, J; Duda, M

    2008-01-01

    Background and purpose: Diet-induced hypercholesterolaemia exacerbates post-myocardial infarction (MI) ventricular remodelling and heart failure, but the mechanism of this phenomenon remains unknown. This study examined whether worsening of post-MI ventricular remodelling induced by dietary hypercholesterolaemia was related to upregulation of angiotensin II type 1 (AT1) receptor in the rat heart. Experimental approach: MI was induced surgically in rats fed normal or high cholesterol diet. Both groups of rats were then assigned to control, atorvastatin, losartan or atorvastatin+losartan-treated subgroups and followed for 8 weeks. Left ventricular (LV) function was assessed with echocardiography. In isolated hearts, LV pressures were measured with a latex balloon and a tip catheter. AT1-receptor density was assessed in LV membranes with radioligand-binding assays. Key results: High cholesterol diet exacerbated LV dilation and dysfunction in post-MI hearts. Atorvastatin or losartan prevented these hypercholesterolaemia-induced effects, whereas their combination was not more effective than each drug alone. AT1 receptors were upregulated 8 weeks after MI, this was further increased by hypercholesterolaemia and restored to baseline levels by atorvastatin. Conclusions and implications: Hypercholesterolaemia exacerbated LV remodelling and dysfunction in post-MI rat hearts and upregulated cardiac AT1 receptors. All these effects were effectively prevented by atorvastatin. Thus, the pleiotropic statin effects may include interference with the renin-angiotensin system through downregulation of AT1 receptors. PMID:18536757

  9. Correlation of Left Ventricular Diastolic Function and Left Ventricular Geometry in Patients with Obstructive Sleep Apnoea Syndrome

    PubMed Central

    Wang, J; Zhang, H; Wu, C; Han, J; Guo, Z; Jia, C; Yang, L; Hao, Y; Xu, K; Liu, X; Si, J

    2015-01-01

    ABSTRACT Background: The aim of this study is to evaluate the correlation of the left ventricular diastolic function and the left ventricular geometry in patients with obstructive sleep apnoea syndrome (OSAS) by echocardiography. Methods: The 181 patients diagnosed with OSAS were divided into the normal geometry group (NG), the concentric remodelling group (CR), the eccentric hypertrophy group (EH) and the concentric hypertrophy group (CH). Pearson correlation analysis and multiple linear regression analysis were performed toward the correlation of the left ventricular diastolic function and the left ventricular geometry. Results: The E peak in the EH and CH group was significantly reduced, with significant difference; the E/A, Em, Am and Em/Am was reduced in the order of the CR, EH and CH groups, while E/Em was increased, and the difference was significant. Pearson correlation analysis revealed that the Em/Am showed significant negative correlations with the left ventricular mass index (LVMI) [r = −0.419] and relative wall thickness (RWT) [r = −0.289], while the E/Em was significantly positively correlated with the LVMI (r = 0.638) and RWT [r = 0.328] (p < 0.001). Multiple linear regression analysis revealed that LVMI and RWT had influence on the Em/Am and E/Em (r2 = 0.402, r2 = 0.107, p < 0.001). The left ventricular diastolic dysfunction was the worst in the CH group. Conclusions: There was correlation between the left ventricular diastolic dysfunction and the changes in cardiac geometry. PMID:26360680

  10. Left ventricular angiography on exercise. A new method of assessing left ventricular function in ischaemic heart disease.

    PubMed Central

    Sharma, B; Goodwin, J F; Raphael, M J; Steiner, R E; Rainbow, R G; Taylor, S H

    1976-01-01

    Left ventricular function was studied in 17 patients with ischaemic heart disease and compared with 4 patients with normal left ventricular function. The patients in the homogeneous group of ischaemic heart disease were further subdivided into those 'without angina' (n=5) and those 'with angina' (n=12), depending upon the presence of angina during supine leg exercise at the time of definitive study. At rest there was no significant difference in the heart rate, cardiac output, stroke volume, and left ventricular end-diastolic pressure (LVEDP) in the three groups. During exercise the cardiac output and stroke volume were significantly depressed and LVEDP was significantly raised in the ischaemic heart disease group as a whole but within this group failed to show any significant difference in patients with and without angina. The left ventricular end-diastolic volume (LVEDV) and end-systolic volume (LVESV) measurements showed clear separation of these three groups only on exercise. On exercise, there was decrease in LVEDV and LVESV (P less than 0.05; P less than 0.02) in the group with normal left ventricular function, no change in the group with ischaemic heart disease without angina, and striking increase in LVEDV and LVESV in the group with ischaemic heart disease and angina (P less than 0.01 and P less than 0.02, respectively). This angiographic method of assessing left ventricular function shows clear separation of the three groups and also highlights the significance of angina. Ejection fraction (EF), a commonly measured parameter of left ventricular function, failed to reflect consistent changes on exercise as compared to values at rest which emphasizes the limitations of the measurement of ejection fraction at rest. Images PMID:1082766

  11. Non-genetic Purification of Ventricular Cardiomyocytes from Differentiating Embryonic Stem Cells through Molecular Beacons Targeting IRX-4

    PubMed Central

    Ban, Kiwon; Wile, Brian; Cho, Kyu-Won; Kim, Sangsung; Song, Ming-Ke; Kim, Sang Yoon; Singer, Jason; Syed, Anum; Yu, Shan Ping; Wagner, Mary; Bao, Gang; Yoon, Young-sup

    2015-01-01

    Summary Isolation of ventricular cardiomyocytes (vCMs) has been challenging due to the lack of specific surface markers. Here we show that vCMs can be purified from differentiating mouse embryonic stem cells (mESCs) using molecular beacons (MBs) targeting specific intracellular mRNAs. We designed MBs (IRX4 MBs) to target mRNA encoding Iroquois homeobox protein 4 (Irx4), a transcription factor specific for vCMs. To purify mESC vCMs, IRX4 MBs were delivered into cardiomyogenically differentiating mESCs, and IRX4 MBs-positive cells were FACS-sorted. We found that, of the cells isolated, ∼98% displayed vCM-like action potentials by electrophysiological analyses. These MB-purified vCMs continuously maintained their CM characteristics as verified by spontaneous beating, Ca2+ transient, and expression of vCM-specific proteins. Our study shows the feasibility of isolating pure vCMs via cell sorting without modifying host genes. The homogeneous and functional ventricular CMs generated via the MB-based method can be useful for disease investigation, drug discovery, and cell-based therapies. PMID:26651608

  12. Prolongation of atrio-ventricular node conduction in a rabbit model of ischaemic cardiomyopathy: Role of fibrosis and connexin remodelling.

    PubMed

    Nisbet, Ashley M; Camelliti, Patrizia; Walker, Nicola L; Burton, Francis L; Cobbe, Stuart M; Kohl, Peter; Smith, Godfrey L

    2016-05-01

    Conduction abnormalities are frequently associated with cardiac disease, though the mechanisms underlying the commonly associated increases in PQ interval are not known. This study uses a chronic left ventricular (LV) apex myocardial infarction (MI) model in the rabbit to create significant left ventricular dysfunction (LVD) 8weeks post-MI. In vivo studies established that the PQ interval increases by approximately 7ms (10%) with no significant change in average heart rate. Optical mapping of isolated Langendorff perfused rabbit hearts recapitulated this result: time to earliest activation of the LV was increased by 14ms (16%) in the LVD group. Intra-atrial and LV transmural conduction times were not altered in the LVD group. Isolated AVN preparations from the LVD group demonstrated a significantly longer conduction time (by approximately 20ms) between atrial and His electrograms than sham controls across a range of pacing cycle lengths. This difference was accompanied by increased effective refractory period and Wenckebach cycle length, suggesting significantly altered AVN electrophysiology post-MI. The AVN origin of abnormality was further highlighted by optical mapping of the isolated AVN. Immunohistochemistry of AVN preparations revealed increased fibrosis and gap junction protein (connexin43 and 40) remodelling in the AVN of LVD animals compared to sham. A significant increase in myocyte-non-myocyte connexin co-localization was also observed after LVD. These changes may increase the electrotonic load experienced by AVN muscle cells and contribute to slowed conduction velocity within the AVN. PMID:27021518

  13. Ventricular arrhythmias in congestive heart failure: clinical significance and management.

    PubMed Central

    Khoshnevis, G R; Massumi, A

    1999-01-01

    The benefit of defibrillator therapy has been well established for patients with LV dysfunction (ejection fraction less than 35%), coronary artery disease, NSVT, and inducible and nonsuppressible ventricular tachycardia. Implantable cardioverter-defibrillator therapy is also indicated for all CHF patients in NYHA functional classes I, II, and III who present with aborted sudden cardiac death, or ventricular fibrillation, or hemodynamically unstable ventricular tachycardia--and also in patients with syncope with no documented ventricular tachycardia but with inducible ventricular tachycardia at electrophysiology study. The ongoing MADIT II trial was designed to evaluate the benefit of prophylactic ICD implantation in these patients (ejection fraction less than 30%, coronary artery disease, and NSVT) without prior risk stratification by PES. The CABG Patch trial concluded that prophylactic placement of an ICD during coronary artery bypass grafting in patients with low ejection fraction and abnormal SAECG is not justifiable. Except for the indications described above, ICD implantation has not been proved to be beneficial as primary or secondary therapy. Until more data are available, patients should be encouraged to enroll in the ongoing clinical trials. PMID:10217470

  14. Detection of false arrhythmia alarms with emphasis on ventricular tachycardia.

    PubMed

    Rodrigues, Rui; Couto, Paula

    2016-08-01

    Our approach to detecting false arrhythmia alarms in the intensive care unit breaks down into several tasks. It involves beat detection on different signals: electrocardiogram, photoplethysmogram and arterial blood pressure. The quality of each channel has to be estimated in order to evaluate the reliability of obtained beat detections. The information about the heart rate from the different channels must be integrated in order to find a final conclusion. Some alarm types require particular detectors as is the case of ventricular fibrillation. To identify false ventricular tachycardia alarms we needed to classify heart beats as normal/ventricular. For that purpose we introduce a new feature, QRS polarity type. This feature was important in order to reduce misclassification of ventricular beats: there was an improvement in the ventricular tachycardia alarm true positive rate from 69% to 81%. However, the true negative rate was reduced from 95% to 69% and our global challenge score (real-time event) dropped from 79.02 to 74.28. Our challenge algorithm achieved the third best score in the 2015 PhysioNet/CinC challenge event 1 (real time). PMID:27454934

  15. Ventricular dysfunction in children with obstructive sleep apnea: radionuclide assessment

    SciTech Connect

    Tal, A.; Leiberman, A.; Margulis, G.; Sofer, S.

    1988-01-01

    Ventricular function was evaluated using radionuclide ventriculography in 27 children with oropharyngeal obstruction and clinical features of obstructive sleep apnea. Their mean age was 3.5 years (9 months to 7.5 years). Conventional clinical assessment did not detect cardiac involvement in 25 of 27 children; however, reduced right ventricular ejection fraction (less than 35%) was found in 10 (37%) patients (mean: 19.5 +/- 2.3% SE, range: 8-28%). In 18 patients wall motion abnormality was detected. In 11 children in whom radionuclide ventriculography was performed before and after adenotonsillectomy, right ventricular ejection fraction rose from 24.4 +/- 3.6% to 46.7 +/- 3.4% (P less than 0.005), and in all cases wall motion showed a definite improvement. In five children, left ventricular ejection fraction rose greater than 10% after removal of oropharyngeal obstruction. It is concluded that right ventricular function may be compromised in children with obstructive sleep apnea secondary to adenotonsillar hypertrophy, even before clinical signs of cardiac involvement are present.

  16. Ventricular dysfunction following direct-current shock atrioventricular junction ablation.

    PubMed

    Warren, R J; Vohra, J K; Chan, W; Lichtenstein, M; Mond, H G; Hunt, D

    1991-02-01

    Catheter-induced His bundle ablation for refractory supraventricular arrhythmias is most commonly performed with direct-current shock energy of 200-300 joules. The high energy pulse delivered by direct-current shock produces a lesion in the atrioventricular node by fulguration, with the residual energy being dissipated as a pressure wave. The effect of direct-current shock His bundle ablation on global and regional ventricular function was assessed in 14 consecutive patients by radionuclide ventriculography performed before and after ablation and again three months later. All studies were performed with ventricular pacing at 110 bpm. Global left ventricular ejection fraction was found to be significantly reduced at the three month study (0.43 +/- 0.03 vs 0.50 +/- 0.03, pre ablation, p = 0.02). A significant reduction in wall-motion score was also seen in six of the seven patients who had normal wall motion in pacing rhythm prior to ablation. Deterioration was mainly seen at the left and right ventricular apices. The observed reduction in ventricular function that follows direct-current shock His bundle ablation may result from myocardial damage from electro-coagulation or from barotrauma and supports continued investigation into alternative, less traumatic energy sources for the procedure. PMID:2036072

  17. Arrhythmogenic right ventricular cardiomyopathy, clinical manifestations, and diagnosis.

    PubMed

    Haugaa, Kristina H; Haland, Trine F; Leren, Ida S; Saberniak, Jørg; Edvardsen, Thor

    2016-07-01

    This review aims to give an update on the pathogenesis, clinical manifestations, and diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC). Arrhythmogenic right ventricular cardiomyopathy is mainly an autosomal dominant inherited disease linked to mutations in genes encoding desmosomes or desmosome-related proteins. Classic symptoms include palpitations, cardiac syncope, and aborted cardiac arrest due to ventricular arrhythmias. Heart failure may develop in later stages. Diagnosis is based on the presence of major and minor criteria from the Task Force Criteria revised in 2010 (TFC 2010), which includes evaluation of findings from six different diagnostic categories. Based on this, patients are classified as having possible, borderline, or definite ARVC. Imaging is important in ARVC diagnosis, including both echocardiography and cardiac magnetic resonance imaging for detecting structural and functional abnormalities, but importantly these findings may occur after electrical alterations and ventricular arrhythmias. Electrocardiograms (ECGs) and signal-averaged ECGs are analysed for depolarization and repolarization abnormalities, including T-wave inversions as the most common ECG alteration. Ventricular arrhythmias are common in ARVC and are considered a major diagnostic criterion if originating from the RV inferior wall or apex. Family history of ARVC and detection of an ARVC-related mutation are included in the TFC 2010 and emphasize the importance of family screening. Electrophysiological studies are not included in the diagnostic criteria, but may be important for differential diagnosis including RV outflow tract tachycardia. Further differential diagnoses include sarcoidosis, congenital abnormalities, myocarditis, pulmonary hypertension, dilated cardiomyopathy, and athletic cardiac adaptation, which may mimic ARVC. PMID:26498164

  18. Is right ventricular mid-septal pacing superior to apical pacing in patients with high degree atrio-ventricular block and moderately depressed left ventricular function?*

    PubMed Central

    Chen, Kang; Mao, Ye; Liu, Shao-hua; Wu, Qiong; Luo, Qing-zhi; Pan, Wen-qi; Jin, Qi; Zhang, Ning; Ling, Tian-you; Chen, Ying; Gu, Gang; Shen, Wei-feng; Wu, Li-qun

    2014-01-01

    Objective: We are aimed to investigate whether right ventricular mid-septal pacing (RVMSP) is superior to conventional right ventricular apical pacing (RVAP) in improving clinical functional capacity and left ventricular ejection fraction (LVEF) for patients with high-degree atrio-ventricular block and moderately depressed left ventricle (LV) function. Methods: Ninety-two patients with high-degree atrio-ventricular block and moderately reduced LVEF (ranging from 35% to 50%) were randomly allocated to RVMSP (n=45) and RVAP (n=47). New York Heart Association (NYHA) functional class, echocardiographic LVEF, and distance during a 6-min walk test (6MWT) were determined at 18 months after pacemaker implantation. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Results: Compared with baseline, NYHA functional class remained unchanged at 18 months, distance during 6MWT (485 m vs. 517 m) and LVEF (36.7% vs. 41.8%) were increased, but BNP levels were reduced (2352 pg/ml vs. 710 pg/ml) in the RVMSP group compared with those in the RVAP group, especially in patients with LVEF 35%–40% (for all comparisons, P<0.05). However, clinical function capacity and LV function measurements were not significantly changed in patients with RVAP, despite the pacing measurements being similar in both groups, such as R-wave amplitude and capture threshold. Conclusions: RVMSP provides a better clinical utility, compared with RVAP, in patients with high-degree atrioventricular block and moderately depressed LV function whose LVEF levels ranged from 35% to 40%. PMID:24903987

  19. Onychomycosis due to Candida parapsilosis in a Child with Ventricular Septal Defect: An Unusual Predisposition

    PubMed Central

    Hosuru Subramanya, Supram; Hamal, Deependra; Nayak, Niranjan; Gokhale, Shishir

    2016-01-01

    Candida parapsilosis is emerging as a potential pathogen for onychomycosis. A 4-year-old male child with perimembranous ventricular septal defect (VSD) was admitted with features of cystitis and was treated with broad spectrum antibiotics. Two weeks later, he developed yellowish discoloration of nails of both hands. The sloughed out nail, on microscopy, showed numerous yeast forms that were identified as Candida parapsilosis by both phenotypic and genotypic methods. Antifungal sensitivity testing of the isolate was performed by microbroth dilution method in accordance with CLSI guidelines. Patient was successfully treated with topical amphotericin B and oral fluconazole. Thus, one should have a high index of suspicion of C. parapsilosis onychomycosis, especially when the patient is in the paediatric age group, presenting with unusual predisposing condition like congenital heart disease, and is on broad spectrum antibiotics. PMID:27195165

  20. On the clinical characterization of impulse and suction force contributions by the diastolic left ventricular vortex

    NASA Astrophysics Data System (ADS)

    Martinez-Legazpi, Pablo; Alhama, Marta; Benito, Yolanda; Bermejo, Javier; Yotti, Raquel; Perez-David, Esther; Barrio, Alicia; Perez-Del-Villar, Candelas; Gonzalez-Mansilla, Ana; Fernandez-Aviles, Francisco; Del Alamo, Juan C.

    2012-11-01

    One of the fluid-dynamic mechanisms that characterize the diastolic phase of the cardiac cycle is the formation of a left ventricular (LV) vortex ring that has been proposed to improve LV filling. However, direct clinical quantification of the contribution of this vortex to LV filling is elusive. In this clinical study, we considered 20 patients with dilated cardiomyopathy (DCM) and 40 healthy volunteers. We have developed and validated a method that derives two-dimensional maps of the LV flow from standard color-Doppler sequences. This study employs the new imaging modality in combination with a vortex identification method and a panel method in order to isolate and estimate the direct contribution of the LV vortex to fluid impulse and suction force during filling in the healthy and diseased populations. Funded by NIH Grant R21HL108268.

  1. A model for the generation of spontaneous yet predictable ventricular arrhythmias.

    PubMed

    Dennis, S C; Hearse, D J; Coltart, D J

    1981-01-01

    Development of an experimental preparation aided to investigate arrhythmogenic and antiarrhythmogenic factors influencing incidence of spontaneous and yet predictable ventricular arrhythmias is described. Using the isolated perfused guinea-pig heart and a system for quantitating rhythm disturbances based on computer-aided statistical analysis of beat-to-beat intervals, a number of factors influencing the incidence of rhythm disturbances were investigated. Manipulation of perfusate composition revealed that, after 'moderate' ischaemia, reperfusion arrhythmias were increased in the presence of noradrenaline and non-glucose fuels. Free fatty acids, unless in the presence of catecholamines, were not particularly arrhythmogenic. In contrast, the presence of pyruvate or lactate, endproduct inhibitors of glycolysis, significantly increased incidence of reflow rhythm disturbances. The dose-dependent arrhythmogenic effects of pyruvate and anti-arrhythmogenic effects of glucose support the thesis that inadequate glycolytic flux could be important in the development of arrhythmias. PMID:7238559

  2. Onychomycosis due to Candida parapsilosis in a Child with Ventricular Septal Defect: An Unusual Predisposition.

    PubMed

    Hosuru Subramanya, Supram; Hamal, Deependra; Nayak, Niranjan; Gokhale, Shishir

    2016-01-01

    Candida parapsilosis is emerging as a potential pathogen for onychomycosis. A 4-year-old male child with perimembranous ventricular septal defect (VSD) was admitted with features of cystitis and was treated with broad spectrum antibiotics. Two weeks later, he developed yellowish discoloration of nails of both hands. The sloughed out nail, on microscopy, showed numerous yeast forms that were identified as Candida parapsilosis by both phenotypic and genotypic methods. Antifungal sensitivity testing of the isolate was performed by microbroth dilution method in accordance with CLSI guidelines. Patient was successfully treated with topical amphotericin B and oral fluconazole. Thus, one should have a high index of suspicion of C. parapsilosis onychomycosis, especially when the patient is in the paediatric age group, presenting with unusual predisposing condition like congenital heart disease, and is on broad spectrum antibiotics. PMID:27195165

  3. Effects of sex and hypertension subtype on haemodynamics and left ventricular diastolic function in older patients with stage 1 hypertension

    PubMed Central

    Fujimoto, Naoki; Okada, Yoshiyuki; Shibata, Shigeki; Best, Stuart A.; Bivens, Tiffany B.; Levine, Benjamin D.; Fu, Qi

    2013-01-01

    Background Hypertension is associated with cardiovascular stiffening and left ventricular diastolic dysfunction, leading to comorbidities such as heart failure with preserved ejection fraction (HFpEF). It is unknown whether sex and hypertension subtype affect haemodynamics and left ventricular function in older individuals. Methods Ninety-five older patients with Stage 1 hypertension (ambulatory awake SBP135–159 mmHg) and 56 normotensive controls were enrolled. Patients were stratified prospectively into isolated systolic hypertension (ISH, DBP <85 mmHg) or systolic-diastolic hypertension (SDH, DBP ≥85 mmHg). Haemodynamics and Doppler variables including early filling (E) and averaged mitral annular (E′mean) velocities were measured during supine rest. Results Ambulatory awake blood pressures (BPs) were the highest in SDH, whereas supine SBP was similar in both hypertensive groups. No sex difference was observed in supine or ambulatory awake BPs in all groups. Stroke volume was similar among groups within the same sex, but smaller in women. Women exhibited faster E, slower E′mean and greater E/E′mean, whereas no group difference was observed in E within the same sex. In women, E′mean was significantly slower in SDH (5.9 ± 1.6 vs. 7.4 ± 1.1 cm/s, P < 0.01) and ISH (6.6 ± 1.6 cm/s, P = 0.07) than controls, resulting in the highest E/E′mean in SDH. In men, E′mean and E/E′mean were similar among the three groups. Conclusion These results suggest that elderly hypertensive women may have left ventricular early diastolic dysfunction and higher estimated filling pressure, consistent with their susceptibility to HFpEF. Women with SDH seemed to have more left ventricular diastolic dysfunction, which might be explained by the greater cumulative afterload when ambulatory. PMID:24077248

  4. Adjustable atrial and ventricular temporary electrode for low-energy termination of tachyarrhythmias early after cardiac surgery.

    PubMed

    Mehmanesh, H; Bauernschmitt, R; Lange, R; Hagl, S

    1999-12-01

    Supraventricular and ventricular tachycardias are common and serious postoperative complications early after cardiac surgery. We introduce a completely removable temporary adjustable defibrillation electrode (TADE) for low energy cardioversion/defibrillation of postoperative atrial and ventricular tachyarrhythmias. The electrode consists of three loops of steel wires connected to one steel wire, which are movable within an isolation sheet for adjusting the active surface to the individual size of the heart chambers. Evaluation of the electrode was performed in 10 open-chest beagles with a mean weight of 25.5 kg. The electrodes were first positioned on the left and right atrium. Atrial fibrillation (AF) was induced via a bipolar temporary heart wire. Atrial defibrillation thresholds (DFTs) were measured according to a step-down shock protocol (5-0.4 J). Thereafter, the electrodes were adjusted and positioned on the right and left ventricle. Ventricular fibrillation (VF) was induced and DFTs were recorded the same way. Aortic flow and pressure and left ventricular pressure were continuously monitored throughout the experiment. For termination of AF, mean DFTs were 0.4 +/- 0 J (lowest possible shock level) with a mean shock impedance of 70 +/- 7.6 ohms. VF was terminated with a mean DFT of 3 +/- 1.1 J with a mean impedance 56.1 +/- 7.9 ohms. Complete transcutaneous removal of the electrodes was possible in all animals without any complications. In conclusion, successful low energy termination of AF and VF is possible with the tested temporary adjustable electrode. A clinical study is planned for further evaluation. PMID:10642135

  5. Tunneling a Pulmonary Artery Graft: A Simplified Way to Insert and Remove a Temporary Right Ventricular Assist Device

    PubMed Central

    Saxena, Pankaj

    2015-01-01

    Right ventricular failure can occur early or late after left ventricular assist device implantation. Support with a right ventricular assist device is needed in patients whose right ventricular failure does not respond to conservative management. The use of a temporary right ventricular assist device can enable the recovery of right ventricular function and avoid the use of a more permanent biventricular assist device, which is associated with complications and higher costs. We present our technique of instituting temporary right ventricular assist device support in patients who have undergone left ventricular assist device implantation. PMID:26664306

  6. Model for end-stage liver disease predicts right ventricular failure in patients with left ventricular assist devices.

    PubMed

    Yost, Gardner L; Coyle, Laura; Bhat, Geetha; Tatooles, Antone J

    2016-03-01

    High rates of right ventricular failure continue to affect postoperative outcomes in patients implanted with left ventricular assist devices (LVADs). Development of right ventricular failure and implantation with right ventricular assist devices is known to be associated with significantly increased mortality. The model for end-stage liver disease (MELD) score is an effective means of evaluating liver dysfunction. We investigated the prognostic utility of postoperative MELD on post-LVAD implantation outcomes. MELD scores, demographic data, and outcomes including length of stay, survival, and postoperative right ventricular failure were collected for 256 patients implanted with continuous flow LVADs. Regression and Kaplan-Meier analyses were used to investigate the relationship between MELD and all outcomes. Increased MELD score was found to be an independent predictor of both right heart failure and necessity for RVAD implantation (OR 1.097, CI 1.040-1.158, p = 0.001; OR 1.121, CI 1.015, p = 0.024, respectively). Patients with RV failure and who underwent RVAD implantation had reduced postoperative survival compared to patients with RV dysfunction (no RV failure = 651.4 ± 609.8 days, RV failure = 392.6 ± 444.8 days, RVAD = 89.3 ± 72.8 days; p < 0.001). In conclusion, MELD can be used to reliably predict postoperative right heart failure and the necessity for RVAD implantation. Those patients with RV failure and RVADs experience significantly increased postoperative mortality compared to those without RV dysfunction. PMID:26187243

  7. Complicated transcatheter closure of postinfarction ventricular acute septal defect.

    PubMed

    Moreno, Nuno; Silva, João Carlos; Andrade, Aurora

    2011-10-01

    The ventricular septal rupture is an uncommon complication of myocardial infarction (MI) with a reported incidence of 0.2% in the thrombolytic era. The outcome remains extremely poor, and surgical defect closure still remains the only therapeutic option improving survival. There are single reports based on a small series of case reports about transcatheter closure of postinfarction ventricular septal defects (VSD) and experience is limited. We present a case of a 71-year-old man with a posteroinferior MI complicated by a ventricular septal rupture with 24 mm width. Due to the severity of the case, surgical approach was denied; we attempted transcatheter closure of the defect in a lifesaving situation. The VSD was partially closed with a 26 mm Amplatzer® septal occluder (AGA Medical Corp., Plymouth, Minnesota) without adequate expansion of the right disc, due the complexity of the tract. The patient died one day after the procedure. PMID:21972171

  8. Postinfarct Left Ventricular Remodelling: A Prevailing Cause of Heart Failure

    PubMed Central

    Galli, Alessio; Lombardi, Federico

    2016-01-01

    Heart failure is a chronic disease with high morbidity and mortality, which represents a growing challenge in medicine. A major risk factor for heart failure with reduced ejection fraction is a history of myocardial infarction. The expansion of a large infarct scar and subsequent regional ventricular dilatation can cause postinfarct remodelling, leading to significant enlargement of the left ventricular chamber. It has a negative prognostic value, because it precedes the clinical manifestations of heart failure. The characteristics of the infarcted myocardium predicting postinfarct remodelling can be studied with cardiac magnetic resonance and experimental imaging modalities such as diffusion tensor imaging can identify the changes in the architecture of myocardial fibers. This review discusses all the aspects related to postinfarct left ventricular remodelling: definition, pathogenesis, diagnosis, consequences, and available therapies, together with experimental interventions that show promising results against postinfarct remodelling and heart failure. PMID:26989555

  9. Imaging of Ventricular Fibrillation and Defibrillation: The Virtual Electrode Hypothesis

    PubMed Central

    Boukens, Bastiaan J.; Gutbrod, Sarah R.; Efimov, Igor R.

    2016-01-01

    Ventricular fibrillation is the major underlying cause of sudden cardiac death. Understanding the complex activation patterns that give rise to ventricular fibrillation requires high resolution mapping of localized activation. The use of multi-electrode mapping unraveled re-entrant activation patterns that underlie ventricular fibrillation. However, optical mapping contributed critically to understanding the mechanism of defibrillation, where multi-electrode recordings could not measure activation patterns during and immediately after a shock. In addition, optical mapping visualizes the virtual electrodes that are generated during stimulation and defibrillation pulses, which contributed to the formulation of the virtual electrode hypothesis. The generation of virtual electrode induced phase singularities during defibrillation is arrhythmogenic and may lead to the induction of fibrillation subsequent to defibrillation. Defibrillating with low energy may circumvent this problem. Therefore, the current challenge is to use the knowledge provided by optical mapping to develop a low energy approach of defibrillation, which may lead to more successful defibrillation. PMID:26238060

  10. Passive ventricular remodeling in cardiac disease: focus on heterogeneity

    PubMed Central

    Kessler, Elise L.; Boulaksil, Mohamed; van Rijen, Harold V. M.; Vos, Marc A.; van Veen, Toon A. B.

    2014-01-01

    Passive ventricular remodeling is defined by the process of molecular ventricular adaptation to different forms of cardiac pathophysiology. It includes changes in tissue architecture, such as hypertrophy, fiber disarray, alterations in cell size and fibrosis. Besides that, it also includes molecular remodeling of gap junctions, especially those composed by Connexin43 proteins (Cx43) in the ventricles that affect cell-to-cell propagation of the electrical impulse, and changes in the sodium channels that modify excitability. All those alterations appear mainly in a heterogeneous manner, creating irregular and inhomogeneous electrical and mechanical coupling throughout the heart. This can predispose to reentry arrhythmias and adds to a further deterioration into heart failure. In this review, passive ventricular remodeling is described in Hypertrophic Cardiomyopathy (HCM), Dilated Cardiomyopathy (DCM), Ischemic Cardiomyopathy (ICM), and Arrhythmogenic Cardiomyopathy (ACM), with a main focus on the heterogeneity of those alterations mentioned above. PMID:25566084

  11. Polymer-based restoration of left ventricular mechanics.

    PubMed

    Lee, Randall J; Hinson, Andy; Helgerson, Sam; Bauernschmitt, Robert; Sabbah, Hani N

    2013-01-01

    Heart failure continues to be a major health care concern with relatively few options for severely advanced heart failure patients. The hallmark of heart failure is the progressive dilatation of the left ventricle, thinning of the left ventricular wall leading to increased wall stress and increased myocardial oxygen consumption. Applying Laplace's law to the failing dilated ventricle, left ventricular augmentation utilizes a tissue engineering strategy to increase wall thickness and reduce chamber diameter, resulting in a decrease in wall stress and improved left ventricular function. A review of the rationale for an in situ tissue engineering approach for this treatment of heart failure and early clinical results of the Algisyl-LVR™ program are presented. PMID:22469060

  12. Laboratory Markers of Ventricular Arrhythmia Risk in Renal Failure

    PubMed Central

    2014-01-01

    Sudden cardiac death continues to be a major public health problem. Ventricular arrhythmia is a main cause of sudden cardiac death. The present review addresses the links between renal function tests, several laboratory markers, and ventricular arrhythmia risk in patients with renal disease, undergoing or not hemodialysis or renal transplant, focusing on recent clinical studies. Therapy of hypokalemia, hypocalcemia, and hypomagnesemia should be an emergency and performed simultaneously under electrocardiographic monitoring in patients with renal failure. Serum phosphates and iron, PTH level, renal function, hemoglobin and hematocrit, pH, inflammatory markers, proteinuria and microalbuminuria, and osmolarity should be monitored, besides standard 12-lead ECG, in order to prevent ventricular arrhythmia and sudden cardiac death. PMID:24982887

  13. Cancer stem cells from a rare form of glioblastoma multiforme involving the neurogenic ventricular wall

    PubMed Central

    2012-01-01

    Background The cancer stem cell (CSC) hypothesis posits that deregulated neural stem cells (NSCs) form the basis of brain tumors such as glioblastoma multiforme (GBM). GBM, however, usually forms in the cerebral white matter while normal NSCs reside in subventricular and hippocampal regions. We attempted to characterize CSCs from a rare form of glioblastoma multiforme involving the neurogenic ventricular wall. Methods We described isolating CSCs from a GBM involving the lateral ventricles and characterized these cells with in vitro molecular biomarker profiling, cellular behavior, ex vivo and in vivo techniques. Results The patient’s MRI revealed a heterogeneous mass with associated edema, involving the left subventricular zone. Histological examination of the tumor established it as being a high-grade glial neoplasm, characterized by polygonal and fusiform cells with marked nuclear atypia, amphophilic cytoplasm, prominent nucleoli, frequent mitotic figures, irregular zones of necrosis and vascular hyperplasia. Recurrence of the tumor occurred shortly after the surgical resection. CD133-positive cells, isolated from the tumor, expressed stem cell markers including nestin, CD133, Ki67, Sox2, EFNB1, EFNB2, EFNB3, Cav-1, Musashi, Nucleostemin, Notch 2, Notch 4, and Pax6. Biomarkers expressed in differentiated cells included Cathepsin L, Cathepsin B, Mucin18, Mucin24, c-Myc, NSE, and TIMP1. Expression of unique cancer-related transcripts in these CD133-positive cells, such as caveolin-1 and −2, do not appear to have been previously reported in the literature. Ex vivo organotypic brain slice co-culture showed that the CD133+ cells behaved like tumor cells. The CD133-positive cells also induced tumor formation when they were stereotactically transplanted into the brains of the immune-deficient NOD/SCID mice. Conclusions This brain tumor involving the neurogenic lateral ventricular wall was comprised of tumor-forming, CD133-positive cancer stem cells, which are likely

  14. Vascular Smooth Muscle Mineralocorticoid Receptor Contributes to Coronary and Left Ventricular Dysfunction After Myocardial Infarction.

    PubMed

    Gueret, Alexandre; Harouki, Najah; Favre, Julie; Galmiche, Guillaume; Nicol, Lionel; Henry, Jean-Paul; Besnier, Marie; Thuillez, Christian; Richard, Vincent; Kolkhof, Peter; Mulder, Paul; Jaisser, Frédéric; Ouvrard-Pascaud, Antoine

    2016-04-01

    Mineralocorticoid receptor (MR) antagonists slow down the progression of heart failure after myocardial infarction (MI), but the cell-specific role of MR in these benefits is unclear. In this study, the role of MR expressed in vascular smooth muscle cells (VSMCs) was investigated. Two months after coronary artery ligation causing MI, mice with VSMC-specific MR deletion (MI-MR(SMKO)) and mice treated with the MR antagonist finerenone (MI-fine) had improved left ventricular compliance and elastance when compared with infarcted control mice (MI-CTL), as well as reduced interstitial fibrosis. Importantly, the coronary reserve assessed by magnetic resonance imaging was preserved (difference in myocardial perfusion before and after induction of vasodilatation, mL mg (-1) min(-1): MI-CTL: 1.1±0.5, nonsignificant; MI-MR(SMKO): 4.6±1.6 [P<0.05]; MI-fine: 3.6±0.7 [P<0.01]). The endothelial function, tested on isolated septal coronary arteries by analyzing the acetylcholine-induced nitric oxide-dependent relaxation, was also improved by MR deletion in VSMCs or by finerenone treatment (relaxation %: MI-CTL: 36±5, MI-MR(SMKO): 54±3, and MI-fine: 76±4; P<0.05). Such impairment of the coronary endothelial function on MI involved an oxidative stress that was reduced when MR was deleted in VSMCs or by finerenone treatment. Moreover, short-term incubation of coronary arteries isolated from noninfarcted animals with low-dose angiotensin-II (10(-9) mol/L) induced oxidative stress and impaired acetylcholine-induced relaxation in CTL but neither in MR(SMKO) nor in mice pretreated with finerenone. In conclusion, deletion of MR in VSMCs improved left ventricular dysfunction after MI, likely through maintenance of the coronary reserve and improvement of coronary endothelial function. MR blockage by finerenone had similar effects. PMID:26902493

  15. A method of intraoperative right ventricular assistance following the Fontan procedure for tricuspid atresia

    PubMed Central

    Livesay, James J.; Cooley, Denton A.; Norman, John C.

    1980-01-01

    A method of temporary intraoperative right ventricular assistance following the Fontan procedure is described in this case report. The multiple etiologic factors and avenues of treatment for postoperative right ventricular failure are discussed. PMID:15216242

  16. Improvement of Right Ventricular Hemodynamics with Left Ventricular Endocardial Pacing during Cardiac Resynchronization Therapy

    PubMed Central

    HYDE, EOIN R.; BEHAR, JONATHAN M.; CROZIER, ANDREW; CLARIDGE, SIMON; JACKSON, TOM; SOHAL, MANAV; GILL, JASWINDER S.; O'NEILL, MARK D.; RAZAVI, REZA; RINALDI, CHRISTOPHER A.

    2016-01-01

    Background Cardiac resynchronization therapy (CRT) with biventricular epicardial (BV‐CS) or endocardial left ventricular (LV) stimulation (BV‐EN) improves LV hemodynamics. The effect of CRT on right ventricular function is less clear, particularly for BV‐EN. Our objective was to compare the simultaneous acute hemodynamic response (AHR) of the right and left ventricles (RV and LV) with BV‐CS and BV‐EN in order to determine the optimal mode of CRT delivery. Methods Nine patients with previously implanted CRT devices successfully underwent a temporary pacing study. Pressure wires measured the simultaneous AHR in both ventricles during different pacing protocols. Conventional epicardial CRT was delivered in LV‐only (LV‐CS) and BV‐CS configurations and compared with BV‐EN pacing in multiple locations using a roving decapolar catheter. Results Best BV‐EN (optimal AHR of all LV endocardial pacing sites) produced a significantly greater RV AHR compared with LV‐CS and BV‐CS pacing (P < 0.05). RV AHR had a significantly increased standard deviation compared to LV AHR (P < 0.05) with a weak correlation between RV and LV AHR (Spearman rs = −0.06). Compromised biventricular optimization, whereby RV AHR was increased at the expense of a smaller decrease in LV AHR, was achieved in 56% of cases, all with BV‐EN pacing. Conclusions BV‐EN pacing produces significant increases in both LV and RV AHR, above that achievable with conventional epicardial pacing. RV AHR cannot be used as a surrogate for optimizing LV AHR; however, compromised biventricular optimization is possible. The beneficial effect of endocardial LV pacing on RV function may have important clinical benefits beyond conventional CRT. PMID:27001004

  17. Predictors of right ventricular failure after left ventricular assist device implantation

    PubMed Central

    Koprivanac, Marijan; Kelava, Marta; Sirić, Franjo; Cruz, Vincent B.; Moazami, Nader; Mihaljević, Tomislav

    2014-01-01

    Number of left ventricular assist device (LVAD) implantations increases every year, particularly LVADs for destination therapy (DT). Right ventricular failure (RVF) has been recognized as a serious complication of LVAD implantation. Reported incidence of RVF after LVAD ranges from 6% to 44%, varying mostly due to differences in RVF definition, different types of LVADs, and differences in patient populations included in studies. RVF complicating LVAD implantation is associated with worse postoperative mortality and morbidity including worse end-organ function, longer hospital length of stay, and lower success of bridge to transplant (BTT) therapy. Importance of RVF and its predictors in a setting of LVAD implantation has been recognized early, as evidenced by abundant number of attempts to identify independent risk factors and develop RVF predictor scores with a common purpose to improve patient selection and outcomes by recognizing potential need for biventricular assist device (BiVAD) at the time of LVAD implantation. The aim of this article is to review and summarize current body of knowledge on risk factors and prediction scores of RVF after LVAD implantation. Despite abundance of studies and proposed risk scores for RVF following LVAD, certain common limitations make their implementation and clinical usefulness questionable. Regardless, value of these studies lies in providing information on potential key predictors for RVF that can be taken into account in clinical decision making. Further investigation of current predictors and existing scores as well as new studies involving larger patient populations and more sophisticated statistical prediction models are necessary. Additionally, a short description of our empirical institutional approach to management of RVF following LVAD implantation is provided. PMID:25559829

  18. Predictors of right ventricular failure after left ventricular assist device implantation.

    PubMed

    Koprivanac, Marijan; Kelava, Marta; Sirić, Franjo; Cruz, Vincent B; Moazami, Nader; Mihaljević, Tomislav

    2014-12-01

    Number of left ventricular assist device (LVAD) implantations increases every year, particularly LVADs for destination therapy (DT). Right ventricular failure (RVF) has been recognized as a serious complication of LVAD implantation. Reported incidence of RVF after LVAD ranges from 6% to 44%, varying mostly due to differences in RVF definition, different types of LVADs, and differences in patient populations included in studies. RVF complicating LVAD implantation is associated with worse postoperative mortality and morbidity including worse end-organ function, longer hospital length of stay, and lower success of bridge to transplant (BTT) therapy. Importance of RVF and its predictors in a setting of LVAD implantation has been recognized early, as evidenced by abundant number of attempts to identify independent risk factors and develop RVF predictor scores with a common purpose to improve patient selection and outcomes by recognizing potential need for biventricular assist device (BiVAD) at the time of LVAD implantation. The aim of this article is to review and summarize current body of knowledge on risk factors and prediction scores of RVF after LVAD implantation. Despite abundance of studies and proposed risk scores for RVF following LVAD, certain common limitations make their implementation and clinical usefulness questionable. Regardless, value of these studies lies in providing information on potential key predictors for RVF that can be taken into account in clinical decision making. Further investigation of current predictors and existing scores as well as new studies involving larger patient populations and more sophisticated statistical prediction models are necessary. Additionally, a short description of our empirical institutional approach to management of RVF following LVAD implantation is provided. PMID:25559829

  19. The effects of intraventricular gradients on left ventricular ejection dynamics.

    PubMed

    Murgo, J P; Alter, B R; Dorethy, J F; Altobelli, S A; Craig, W E; McGranahan, G M

    1983-11-01

    The generation of abnormal gradients between the apical cavity and the subaortic valvular region of the left ventricle in patients with hypertrophic cardiomyopathy (HCM) has traditionally been equated to a dynamic obstruction to left ventricular outflow. To examine this concept in more detail, left ventricular ejection dynamics were studied during cardiac catheterization in 30 patients with HCM and 29 patients with no evidence of cardiovascular disease. Using multisensor catheterization techniques, ascending aortic flow velocity and micromanometer left ventricular and aortic pressures were simultaneously recorded during rest (n = 47). Dynamic left ventricular emptying was also analyzed with frame-by-frame angiography (n = 46). The temporal distribution of left ventricular outflow was independently derived from both flow velocity and angiographic techniques. The HCM patients were subdivided into three groups: I, intraventricular gradients at rest (n = 9); II, intraventricular gradients only with provocation (n = 12); III, no intraventricular gradients despite provocation (n = 9). Expressed as a precentage of the available systolic ejection period (%SEP), the time required for ejection of the total stroke volume was (mean +/- 1 S.D.): Group I, 69 +/- 17% (flow), 64 +/- 6% (angio); Group II, 63 +/- 14% (flow), 65 +/- 6% (angio); Group III, 61 +/- 16% (flow), 62 +/- 4% (angio); control group, 90 +/- 5% (flow) 86 +/- 10% (angio). No significant difference was observed between any of the three HCM subgroups, but, compared with the control group, ejection was completed much earlier in systole independent of the presence or absence of intraventricular gradients. The presence of coexisting mitral regurgitation in 12 of the HCM patients did not alter these results. This study demonstrates that 'outflow obstruction', as traditionally defined by the presence of an abnormal intraventricular pressure gradient and systolic anterior motion of the mitral valve, does not impede left

  20. Establishment of a chronic left ventricular aneurysm model in rabbit

    PubMed Central

    Xiao, Cang-Song; Gao, Chang-Qing; Li, Li-Bing; Wang, Yao; Zhao, Tao; Ye, Wei-Hua; Ren, Chong-Lei; Liu, Zhi-Yong; Wu, Yang

    2014-01-01

    Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm (LVA) in rabbits. Methods Acute myocardial infarction (AMI) was induced in 35 rabbits via concomitant ligation of the left anterior descending (LAD) coronary artery and the circumflex (Cx) branch at the middle portion. Development of AMI was confirmed by ST segment elevation and akinesis of the occluded area. Echocardiography, pathological evaluation, and agar intra-chamber casting were utilized to validate the formation of LVA four weeks after the surgery. Left ventricular end systolic pressure (LVESP) and diastolic pressure (LVEDP) were measured before, immediately after and four weeks after ligation. Dimensions of the ventricular chamber, thickness of the interventricular septum (IVS) and the left ventricular posterior wall (LVPW) left ventricular end diastolic volume (LVEDV), systolic volume (LVESV), and ejection fraction (EF) were recorded by echocardiogram. Results Thirty one (88.6%) rabbits survived myocardial infarction and 26 of them developed aneurysm (83.9%). The mean area of aneurysm was 33.4% ± 2.4% of the left ventricle. LVEF markedly decreased after LVA formation, whereas LVEDV, LVESV and the thickness of IVS as well as the dimension of ventricular chamber from apex to mitral valve annulus significantly increased. LVESP immediately dropped after ligation and recovered to a small extent after LVA formation. LVEDP progressively increased after ligation till LVA formation. Areas in the LV that underwent fibrosis included the apex, anterior wall and lateral wall but not IVS. Agar intra-chamber cast showed that the bulging of LV wall was prominent in the area of aneurysm. Conclusions Ligation of LAD and Cx at the middle portion could induce development of LVA at a mean area ratio of 33.4% ± 2.4% which involves the apex, anterior wall and lateral wall of the left ventricle. PMID:25009567

  1. Modeling CICR in rat ventricular myocytes: voltage clamp studies

    PubMed Central

    2010-01-01

    Background The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR) in cardiac myocytes, with voltage clamp (VC) studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect Ca2+ loading of the sarcoplasmic reticulum (SR), and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR Ca2+ release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic Ca2+ concentration ([Ca2+]myo). Methods The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU), in which resides the mechanistic basis of CICR). The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed Ca2+ channels (trigger-channel and release-channel). It releases Ca2+ flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[Ca2+]myo. Results Our model reproduces measured VC data published by several laboratories, and generates graded Ca2+ release at high Ca2+ gain in a homeostatically-controlled environment where [Ca2+]myo is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR Ca2+ release, its activation by trigger Ca2+, and its refractory characteristics

  2. Backscatter and attenuation characterization of ventricular myocardium

    NASA Astrophysics Data System (ADS)

    Gibson, Allyson Ann

    2009-12-01

    This Dissertation presents quantitative ultrasonic measurements of the myocardium in fetal hearts and adult human hearts with the goal of studying the physics of sound waves incident upon anisotropic and inhomogeneous materials. Ultrasound has been used as a clinical tool to assess heart structure and function for several decades. The clinical usefulness of this noninvasive approach has grown with our understanding of the physical mechanisms underlying the interaction of ultrasonic waves with the myocardium. In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could be achieved at more typical clinical frequencies. Ultrasonic data analyses demonstrated different patterns and relative levels of backscatter and attenuation from the myocardium of the left ventricle and the right ventricle. Ultrasonic data of adult human hearts were acquired with a clinical imaging system and quantified by their magnitude and time delay of cyclic variation of myocardial backscatter. The results were analyzing using Bayes Classification and ROC analysis to quantify potential advantages of using a combination of two features of cyclic variation of myocardial backscatter over using only one or the other feature to distinguish between groups of subjects. When the subjects were classified based on hemoglobin A1c, the homeostasis model assessment of insulin resistance, and the ratio of triglyceride to high-density lipoprotein-cholesterol, differences in the magnitude and normalized time delay of cyclic variation of myocardial backscatter were observed. The cyclic variation results also suggested a trend toward a larger area under the ROC curve when information from magnitude and time delay of cyclic variation is combined using Bayes classification than when

  3. Mechanisms of Ventricular Arrhythmias: From Molecular Fluctuations to Electrical Turbulence

    PubMed Central

    Qu, Zhilin; Weiss, James N.

    2015-01-01

    Ventricular arrhythmias have complex causes and mechanisms. Despite extensive investigation involving many clinical, experimental, and computational studies, effective biological therapeutics are still very limited. In this article, we review our current understanding of the mechanisms of ventricular arrhythmias by summarizing the state of knowledge spanning from the molecular scale to electrical wave behavior at the tissue and organ scales and how the complex nonlinear interactions integrate into the dynamics of arrhythmias in the heart. We discuss the challenges that we face in synthesizing these dynamics to develop safe and effective novel therapeutic approaches. PMID:25340965

  4. Left Ventricular Outflow Tract Pseudoaneurysm after Aortic Valve Replacement

    PubMed Central

    Shariff, Masood A.; Martingano, Daniel; Khan, Usman; Goyal, Nikhil; Sharma, Raman; Rizvi, Syed B.; Motivala, Apurva; Asgarian, Kourosh T.; Nabagiez, John P.

    2015-01-01

    Left ventricular outflow tract pseudoaneurysm is an uncommon complication following aortic valve replacement (AVR), occurring most frequently secondary to endocarditis. We present a case of a 47-year-old female with a history of intravenous drug abuse and a past surgical history of two AVRs (2001 and 2009 with aortic root replacement for endocarditis) who presented with symptoms of lower extremity weakness. Subsequent radiologic imaging revealed the presence of a left ventricular outflow tract pseudoaneurysm, which was surgically managed with a homologous conduit. PMID:27175367

  5. Ion beam sputter-etched ventricular catheter for hydrocephalus shunt

    NASA Technical Reports Server (NTRS)

    Banks, B. A. (Inventor)

    1983-01-01

    A cerebrospinal fluid shunt in the form of a ventricular catheter for controlling the condition of hydrocephalus by relieving the excessive cerebrospinal fluid pressure is described. A method for fabrication of the catheter and shunting the cerebral fluid from the cerebral ventricles to other areas of the body is also considered. Shunt flow failure occurs if the ventricle collapse due to improper valve function causing overdrainage. The ventricular catheter comprises a multiplicity of inlet microtubules. Each microtubule has both a large openings at its inlet end and a multiplicity of microscopic openings along its lateral surfaces.

  6. Rotational angiography of left ventricle to guide ventricular tachycardia ablation.

    PubMed

    Wolf, Jiri; Starek, Zdenek; Jez, Jiri; Lehar, Frantisek; Lukasova, Marketa; Kulik, Tomas; Novak, Miroslav

    2015-06-01

    Three-dimensional rotational angiography (3 DRA) is a novel imaging method introduced to guide complex catheter ablations of the left atrium. Our aim was to investigate the feasibility of the method in visualization of left ventricular anatomy and to develop a corresponding protocol for guidance of ventricular tachycardia ablation. We performed 3D rotational angiography in 13 patients using a direct left atrial protocol for data acquisition and the 3D reconstruction of the left ventricle was achieved in all patients. Clinical data comparison has proved lower use of radiation and contrast medium during 3 DRA-guided ablations as compared to CT-guided procedures. PMID:25761532

  7. Mechanisms of ventricular arrhythmias: from molecular fluctuations to electrical turbulence.

    PubMed

    Qu, Zhilin; Weiss, James N

    2015-01-01

    Ventricular arrhythmias have complex causes and mechanisms. Despite extensive investigation involving many clinical, experimental, and computational studies, effective biological therapeutics are still very limited. In this article, we review our current understanding of the mechanisms of ventricular arrhythmias by summarizing the state of knowledge spanning from the molecular scale to electrical wave behavior at the tissue and organ scales and how the complex nonlinear interactions integrate into the dynamics of arrhythmias in the heart. We discuss the challenges that we face in synthesizing these dynamics to develop safe and effective novel therapeutic approaches. PMID:25340965

  8. Overview of left ventricular outpouchings on cardiac magnetic resonance imaging

    PubMed Central

    Kumar, Sanjeev

    2015-01-01

    Left ventricular outpouchings commonly include aneurysm, pseudoaneurysm, and diverticulum and are now being increasingly detected on imaging. Distinction between these entities is of prime importance to guide proper management as outcomes for these entities differ substantially. Chest radiograph is usually nonspecific in their diagnosis. Echocardiography, multi-detector computed tomography evaluation and angiography are helpful in the diagnosis with their inherit limitations. Cardiac magnetic resonance imaging (MRI) is emerging as a very useful tool that allows simultaneous anatomical and functional evaluation along with tissue characterization, which has diagnostic, theraputic and prognostic implications. This article gives an overview of left ventricular outpouchings with special emphasis on their differentiation using cardiac MRI. PMID:26675616

  9. Transcatheter patch occlusion of perimembranous ventricular septal defects.

    PubMed

    Sideris, Eleftherios B; Macuil, Benjamin; Varvarenko, Victor; Toumanides, Savvas

    2005-06-15

    Sixteen surgical candidates for ventricular septal defect correction were brought to the catheterization laboratory for transcatheter patch occlusion. There were 3 cases of nonrestrictive ventricular septal defects, including 2 with malalignment (tetralogy of Fallot). All patients, except those with tetralogy of Fallot who were cyanotic, had large left-right shunts. They were all corrected through the femoral vein. All defects with the exception of 2 were successfully occluded (12 full occlusions, 2 residual shunts). On follow-up, there were no embolizations, aortic insufficiency, or other complications. The method appears effective and relatively safe, and could challenge the current surgical standard of treatment. PMID:15950588

  10. Management of Traumatic Sinus of Valsalva-Right Ventricular Fistulae

    PubMed Central

    Murphy, J. Peter; Weiland, Anne P.; Adams, Phillip R.; Walker, William E.

    1986-01-01

    Residual intracardiac defects following penetrating injuries to the heart require thorough invasive evaluation and strong consideration for operative repair based upon the degree of hemodynamic compromise. Traumatic aortico-right ventricular fistulae result in high flow left-to-right shunts, and are associated with early onset of congestive failure. Operative repair requires utilization of total cardiopulmonary bypass, ventriculotomy and aortotomy to allow for thorough inspection of the ventricular septum, aortic valve cusps, and coronary ostia. Obliteration of both ends of the fistula (septal and sinus of Valsalva repair) minimizes the risk of recurrence. Images PMID:15227364

  11. Ablation of Ventricular Tachycardia in Patients with Ischemic Cardiomyopathy.

    PubMed

    Garabelli, Paul; Stavrakis, Stavros; Po, Sunny S

    2016-03-01

    Ventricular tachycardias (VTs) occurring after prior myocardial infarction are usually caused by reentrant circuits formed by surviving myocardial bundles. Although part of the reentrant circuits may be located in the midmyocardium or epicardium, most of the VTs can be safely and successfully ablated by endocardial ablation targeting the late potentials/local abnormal ventricular activation, which are surrogates for the surviving myocardial bundles. A combination of activation, substrate, pace, and entrainment mapping, as well as the use of contact force catheters, further improves ablation success and safety. PMID:26920180

  12. Determination of left ventricular mass through SPECT imaging

    NASA Astrophysics Data System (ADS)

    Zárate-Morales, A.; Rodríguez-Villafuerte, M.; Martínez-Rodríguez, F.; Arévila-Ceballos, N.

    1998-08-01

    An edge detection algorithm has been applied to estimate left ventricular (LV) mass from single photon emission computed tomography (SPECT) thallium-201 images. The algorithm was validated using SPECT images of a phantom. The algorithm was applied to 20 patient studies from the Hospital de Cardiologia, Centro Médico Nacional Siglo XXI. Left ventricular masses derived from the stress and redistribution studies were highly correlated (r=0.96). The average LV masses obtained were 162±37 g and 169±34 g in the redistribution and stress studies, respectively.

  13. Determination of left ventricular mass through SPECT imaging

    SciTech Connect

    Zarate-Morales, A.; Rodriguez-Villafuerte, M.; Martinez-Rodriguez, F.; Arevila-Ceballos, N.

    1998-08-28

    An edge detection algorithm has been applied to estimate left ventricular (LV) mass from single photon emission computed tomography (SPECT) thallium-201 images. The algorithm was validated using SPECT images of a phantom. The algorithm was applied to 20 patient studies from the Hospital de Cardiologia, Centro Medico Nacional Siglo XXI. Left ventricular masses derived from the stress and redistribution studies were highly correlated (r=0.96). The average LV masses obtained were 162{+-}37 g and 169{+-}34 g in the redistribution and stress studies, respectively.

  14. Adjuvant therapy with methylene blue in the treatment of right ventricular failure after pulmonary embolectomy.

    PubMed

    Raikhelkar, Jayashree K; Milla, Federico; Darrow, Bruce; Scurlock, Corey

    2011-04-01

    Severe pulmonary embolism often leads to right ventricular failure after surgical embolectomy secondary to ischaemia reperfusion injury and acute lung injury (ALI). Acute right ventricular dysfunction is traditionally treated with inotropes and vasopressors to maintain cardiac output and coronary perfusion as well as selective pulmonary vasodilators to provide right ventricular afterload reduction. We report the first case of utilisation of methylene (MB) in a patient with acute right ventricular failure and vasoplegic shock after surgical pulmonary embolectomy. PMID:20952252

  15. Mismatch Between Cardiac Perfusion, Sympathetic Innervation, and Left Ventricular Electroanatomical Map in a Patient with Recurrent Ventricular Tachycardia

    PubMed Central

    Jungen, Christiane; von Gogh, Gwendolyn; Schmitt, Christiane; Kuklik, Pawel; Hoffmann, Boris; Nakajima, Kenichi; Willems, Stephan; Mester, Janos; Meyer, Christian

    2016-01-01

    Patient: Male, 69 Final Diagnosis: Recurrent ventricular tachycardia Symptoms: Multiple ICD shocks Medication: — Clinical Procedure: Ventricular tachycardia ablation Specialty: Cardiology Objective: Rare co-existance of disease or pathology Background: Regional cardiac sympathetic denervation causes electrophysiological heterogeneity and has been found to be a predictor of potentially lethal VT. Case Report: We present the case of 69-year-old patient admitted with recurrent ventricular tachycardia and a history of anterior myocardial infarction. In line with Tc-99m-MIBI-SPECT perfusion imaging, electroanatomical mapping revealed extensive LV anterior scarring as detected by low-voltage areas. Surprisingly, I-123-MIBG-SPECT showed an extensive deficit of sympathetic innervation inferior (mismatch) and anterolateral (match). Conclusions: Combination of electroanatomical mapping with tomographic imaging of innervation and perfusion might improve our understanding of the neural trigger of VT after myocardial infarction or substrate-based catheter ablation. PMID:27109542

  16. Minimally Invasive Right Ventricular Assist Device Implantation in a Patient with HeartWare left ventricular Assist Device.

    PubMed

    Maxhera, Bujar; Albert, Alexander; Westenfeld, Ralf; Boeken, Udo; Lichtenberg, Artur; Saeed, Diyar

    2015-01-01

    Many centers reported positive outcome after left ventricular assist devices (LVADs) implantation using a minimally invasive approach. The main drawback of this minimally invasive approach is the feasibility of right ventricular assist device (RVAD) implantation with direct cannulation of the pulmonary artery in cases of perioperative right ventricular failure (RVF). We report our experience with a 41-year-old male patient who was supported with a temporary RVAD using J-sternotomy approach for RVF after LVAD implantation. No technical issue was encountered, and the patient's condition stabilized immediately after RVAD implantation. However, several days later, the patient developed severe septic shock caused by pneumonia and died on the postoperative day 15 after RVAD implantation. PMID:25914955

  17. Ventricular septal defect and double-chambered right ventricle in an alpaca.

    PubMed

    Poser, Helen; Dalla Pria, Angela; De Benedictis, Giulia M; Stelletta, Calogero; Berlanda, Michele; Guglielmini, Carlo

    2015-03-01

    A 20-month-old male alpaca was referred for evaluation of a cardiac murmur evident since birth. Echocardiography identified a ventricular septal defect (VSD) and a fibro-muscular band causing a stenosis of the right ventricular outflow tract. Right ventricular catheterization and selective angiography confirmed the diagnosis of VSD and double-chambered right ventricle with bidirectional shunting. PMID:25595611

  18. Short Communication: Conformal Therapy for Peri-Ventricular Brain Tumors: Is Target Volume Deformation an Issue?

    SciTech Connect

    Bauman, Glenn Woodford, Curtis; Yartsev, Slav

    2008-04-01

    Physiologic variations in ventricular volumes could have important implications for treating patients with peri-ventricular brain tumors, yet no data exist in the literature addressing this issue. Daily megavoltage computed tomography (CT) scans in a patient with neurocytoma receiving fractionated radiation revealed minimal changes, suggesting that margins accounting for ventricular deformation are not necessary.

  19. Regional myocardial shape and dimensions of the working isolated canine left ventricle

    NASA Technical Reports Server (NTRS)

    Ritman, E.; Tsuiki, K.; Donald, D.; Wood, E. H.

    1975-01-01

    Angiographic experiments were performed on isolated canine left ventricle preparations using donor dog to supply blood to the coronary circulation via a rotary pump to control coronary flow. The angiographic record was transferred from video tape to video disk for detailed uninterrupted sequential analysis at a frequency of 60 fields/sec. It is shown that the use of a biplane X-ray technique and a metabolically supported isolated canine left ventricle preparation provides an angiographically ideal means of measuring the mechanical dynamics of the myocardium while the intact left ventricular myocardial structure and electrical activation pattern retain most of the in situ ventricular characteristics. In particular, biplane X-ray angiography of the left ventricle can provide estimates of total ventricular function such as ejection fraction, stroke volume, and myocardial mass correct to within 15% under the angiographically ideal conditions of the preparation.

  20. Ectopia cordis with a double outlet right ventricle, large ventricular septal defect, malposed great arteries and left ventricular hypoplasia.

    PubMed

    Malik, Rabiya; Zilberman, Mark V; Tang, Liwen; Miller, Susan; Pandian, Natesa G

    2015-03-01

    Ectopia cordis, defined as partial or complete displacement of the heart outside of the thoracic cavity, is a rare congenital malformation. If not surgically corrected during the early years of life, ectopia cordis can prove to be a fatal abnormality. However, due to the presence of multiple intracardiac and extracardiac malformations, a corrective surgery might not always be successful. The pathology of ectopia cordis with a double outlet right ventricle, large ventricular septal defect, malposed great arteries and left ventricular hypoplasia is discussed, highlighting the complexities involved in such a rare disorder. PMID:25409882

  1. Ablating Premature Ventricular Complexes: Justification, Techniques, and Outcomes

    PubMed Central

    Noheria, Amit; Deshmukh, Abhishek; Asirvatham, Samuel J.

    2015-01-01

    We reviewed the underlying principles that allow for safe and effective ablation for premature ventricular complexes. Clinical scenarios that necessitate consideration for ablation, the underlying anatomy, and the unique consideration to maximize energy delivery without compromising safety are sequentially examined. PMID:26306129

  2. [Therapeutic strategies for postinfarction left ventricular free wall rupture].

    PubMed

    Koyanagi, Toshiya; Shimokawa, T; Ida, T; Kasegawa, H; Tobaru, T; Sumiyoshi, T

    2005-04-01

    We treated 93 patients who developed left ventricular free wall rupture after acute myocardial infarction. Medical management including pericardial drainage was performed in 78 patients (84%), but 67 of them died. All 11 surviving patients showed an oozing type rupture. Surgical repair was performed in 15 patients (16%). As a result, 9 patients died and 6 survived. All but 1 of the patients who died presented with a blow-out rupture. Blow-out type rupture occurred in 3 and oozing type rupture in 3 of the surviving patients. One patient with blow-out type rupture underwent implantation of a left ventricular assist device following percutaneous cardiopulmonary support (PCPS), because of low output syndrome after the operation. The device was successfully removed 7 days after implantation. In all of the 3 patients with oozing type rupture, sutureless technique was successfully performed using fibrin-glue or fibrin-glue sheet fixation. After a mean follow-up period of 7 years after operation, 5 of 6 are still alive. To improve the clinical outcome of left ventricular free wall rupture, it is important for surgeons to closely liaise with physicians, to perform surgical repair as soon as possible, and to utilize a circulatory support system after operation. Therefore, we developed a new PCPS system compatible with emergency cardiac surgery and a new left ventricular assist system draining via the left ventricle. PMID:15828243

  3. [First degree atrio-ventricular block in acute thyrotoxicosis].

    PubMed

    Vilches, Antonio R; Lerman, Jorge

    2004-01-01

    Thyrotoxicosis may present with a variety of cardiovascular symptoms. Sinus tachycardia is the most frequently encountered electrocardiographic abnormality and conduction disturbances are extremely uncommon. We present a case of first degree atrio-ventricular block in a patient with newly diagnosed hyperthyroidism and discuss the underlying pathophysiological mechanisms and the clinical implications from the internist's standpoint. PMID:15034958

  4. Incomplete ventricular septal rupture following blunt chest trauma.

    PubMed

    Tsikaderis, D; Dardas, P; Hristoforidis, H

    2000-02-01

    Nonpenetrating cardiac trauma should be considered in the diagnosis of electrocardiographic changes after road traffic accidents. Transesophageal echocardiography is the most useful noninvasive technique for the diagnosis of cardiac trauma. This paper reports the case of a patient with traumatic contusion of the ventricular septum following a fall from a 20 m height onto the roof of a car. PMID:10676607

  5. Deadly proposal: a case of catecholaminergic polymorphic ventricular tachycardia.

    PubMed

    Heiner, Jason D; Bullard-Berent, Jeffrey H; Inbar, Shmuel

    2011-11-01

    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare adrenergically mediated arrhythmogenic disorder classically induced by exercise or emotional stress and found in structurally normal hearts. It is an important cause of cardiac syncope and sudden death in childhood. Catecholaminergic polymorphic ventricular tachycardia is a genetic cardiac channelopathy with known mutations involving genes affecting intracellular calcium regulation. We present a case of a 14-year-old boy who had cardiopulmonary arrest after an emotionally induced episode of CPVT while attempting to invite a girl to the school dance. Review of his presenting cardiac rhythm, induction of concerning ventricular arrhythmias during an exercise stress test, and genetic testing confirmed the diagnosis of CPVT. He recovered fully and was treated with β-blocker therapy and placement of an implantable cardioverter-defibrillator. In this report, we discuss this rare but important entity, including its molecular foundation, clinical presentation, basics of diagnosis, therapeutic options, and implications of genetic testing for family members. We also compare CPVT to other notable cardiomyopathic and channelopathic causes of sudden death in youth including hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia, long QT syndrome, short QT syndrome, and Brugada syndrome. PMID:22068070

  6. Ventricular fibrillation and tachycardia classification using a machine learning approach.

    PubMed

    Li, Qiao; Rajagopalan, Cadathur; Clifford, Gari D

    2014-06-01

    Correct detection and classification of ventricular fibrillation (VF) and rapid ventricular tachycardia (VT) is of pivotal importance for an automatic external defibrillator and patient monitoring. In this paper, a VF/VT classification algorithm using a machine learning method, a support vector machine, is proposed. A total of 14 metrics were extracted from a specific window length of the electrocardiogram (ECG). A genetic algorithm was then used to select the optimal variable combinations. Three annotated public domain ECG databases (the American Heart Association Database, the Creighton University Ventricular Tachyarrhythmia Database, and the MIT-BIH Malignant Ventricular Arrhythmia Database) were used as training, test, and validation datasets. Different window sizes, varying from 1 to 10 s were tested. An accuracy (Ac) of 98.1%, sensitivity (Se) of 98.4%, and specificity (Sp) of 98.0% were obtained on the in-sample training data with 5 s-window size and two selected metrics. On the out-of-sample validation data, an Ac of 96.3% ± 3.4%, Se of 96.2% ± 2.7%, and Sp of 96.2% ± 4.6% were obtained by fivefold cross validation. The results surpass those of current reported methods. PMID:23899591

  7. Ventricular arrhythmias and the His-Purkinje system.

    PubMed

    Haissaguerre, Michel; Vigmond, Edward; Stuyvers, Bruno; Hocini, Meleze; Bernus, Olivier

    2016-03-01

    Ventricular arrhythmias are a major cause of sudden death, which accounts for approximately half of cardiac mortality. The His-Purkinje system is composed of specialized cells responsible for the synchronous activation of the ventricles. However, experimental studies show that the Purkinje system can be arrhythmogenic during electrolyte imbalance, after exposure to various drugs, and in myocardial ischaemia, during which Purkinje cells can survive in anaerobic conditions. Purkinje cells can generate both automatic and triggered focal rhythms, and their network configuration can accommodate re-entrant circuits. In humans, a variety of monomorphic ventricular tachycardias can be sustained within the architecture of the Purkinje branches. Furthermore, discrete Purkinje sources can serve as critical triggers of ventricular fibrillation in a wide spectrum of patients with structural heart disease or with an apparently normal heart. In drug-resistant cases of monomorphic and polymorphic Purkinje-related ventricular tachycardias, catheter ablation is a very effective treatment. The specific transcriptional signatures and functional properties of Purkinje cells, including their intracellular calcium dynamics, underlie their extreme arrhythmogenicity. However, the identification of vulnerable individuals remains challenging, and the molecular mechanisms of Purkinje-related arrhythmias have to be characterized further to enable the development of interventions to prevent lethal cardiac arrhythmias. PMID:26727298

  8. Electrocardiographic artifact due to a mobile phone mimicking ventricular tachycardia.

    PubMed

    Duan, Xu

    2014-01-01

    A case of electrocardiographic artifact due to mobile a phone mimicking ventricular tachycardia was presented. The artifact was discriminated by close scrutiny of ECG and was attributed to a mobile phone because it was simultaneous with mobile phone game. PMID:24581928

  9. Arrhythmogenic right ventricular cardiomyopathy in a patient with schizophrenia

    PubMed Central

    Kawasaki, Kenta; Miyaji, Kotaro; Kodera, Satoshi; Suzuki, Yoshio; Kanda, Junji; Ikeda, Masayuki

    2015-01-01

    Key Clinical Message People with schizophrenia are at greater risk of cardiovascular morbidity and mortality than the general population. Arrhythmogenic right ventricular cardiomyopathy is a recognized cause of sudden cardiac death in young people. This report discusses the necessity for close cardiac evaluation to reduce incidence of sudden death in people with schizophrenia. PMID:25984311

  10. Mechanisms of ranolazine's dual protection against atrial and ventricular fibrillation

    PubMed Central

    Verrier, Richard L.; Kumar, Kapil; Nieminen, Tuomo; Belardinelli, Luiz

    2013-01-01

    Coronary artery disease and heart failure carry concurrent risk for atrial fibrillation and life-threatening ventricular arrhythmias. We review evidence indicating that at therapeutic concentrations, ranolazine has potential for dual suppression of these arrhythmias. Mechanisms and clinical implications are discussed. PMID:23220484

  11. Calcium-sensing receptor induces rat neonatal ventricular cardiomyocyte apoptosis

    SciTech Connect

    Sun Yihua; Liu Meina; Li Hong; Shi Sa; Zhao Yajun; Wang Rui; Xu Changqing . E-mail: syh200415@yahoo.com.cn

    2006-12-01

    The calcium-sensing receptor (CaSR) exists in many tissues, and its expression has been identified in rat cardiac tissue. However, Physiological importance and pathophysiological involvement of CaSR in homeostatic regulation of cardiac function are unclear. To investigate the relation of CaSR and apoptosis in cardiomyocytes, we examined the role of the CaSR activator gadolinium chloride (GdCl{sub 3}) in rat neonatal ventricular cardiomyocytes. Expression of the CaSR protein was observed by Western blot. The apoptotic ratio of rat neonatal ventricular cardiomyocytes was measured with flow cytometry and immunofluorescence techniques. A laser scan confocal microscope was used to detect the intracellular concentration of calcium ([Ca{sup 2+}]{sub i}) in rat neonatal ventricular cardiomyocytes using the acetoxymethyl ester of fluo-3 (fluo-3/(AM)) as a fluorescent dye. The results showed that GdCl{sub 3} increased the phosphorylation of extracellular signal-regulated protein kinase (ERK), c-Jun NH{sub 2}-terminal protein kinases (JNK), and p38. GdCl{sub 3} also activated caspase 9 and increased apoptosis in myocyte by increasing [Ca{sup 2+}]{sub i}. In conclusion, these results suggest that CaSR promotes cardiomyocyte apoptosis in rat neonatal ventricular cardiomyocytes through activation of mitogen-activated protein kinases and caspase 9 signaling pathways.

  12. Technique to avoid left ventricular outflow tract obstruction.

    PubMed

    Gualis, Javier; Castaño, Mario; Martínez-Comendador, Jose Manuel

    2016-06-01

    Preserving the subvalvular mitral valve apparatus during mitral valve replacement is extremely important to minimize progressive postoperative left ventricular remodeling and dysfunction. We describe a simple and reproducible surgical technique that prevents the complications that can occur after total mitral anterior leaflet preservation. PMID:26993109

  13. Oxidative stress decreases microtubule growth and stability in ventricular myocytes.

    PubMed

    Drum, Benjamin M L; Yuan, Can; Li, Lei; Liu, Qinghang; Wordeman, Linda; Santana, L Fernando

    2016-04-01

    Microtubules (MTs) have many roles in ventricular myocytes, including structural stability, morphological integrity, and protein trafficking. However, despite their functional importance, dynamic MTs had never been visualized in living adult myocytes. Using adeno-associated viral vectors expressing the MT-associated protein plus end binding protein 3 (EB3) tagged with EGFP, we were able to perform live imaging and thus capture and quantify MT dynamics in ventricular myocytes in real time under physiological conditions. Super-resolution nanoscopy revealed that EB1 associated in puncta along the length of MTs in ventricular myocytes. The vast (~80%) majority of MTs grew perpendicular to T-tubules at a rate of 0.06μm∗s(-1) and growth was preferentially (82%) confined to a single sarcomere. Microtubule catastrophe rate was lower near the Z-line than M-line. Hydrogen peroxide increased the rate of catastrophe of MTs ~7-fold, suggesting that oxidative stress destabilizes these structures in ventricular myocytes. We also quantified MT dynamics after myocardial infarction (MI), a pathological condition associated with increased production of reactive oxygen species (ROS). Our data indicate that the catastrophe rate of MTs increases following MI. This contributed to decreased transient outward K(+) currents by decreasing the surface expression of Kv4.2 and Kv4.3 channels after MI. On the basis of these data, we conclude that, under physiological conditions, MT growth is directionally biased and that increased ROS production during MI disrupts MT dynamics, decreasing K(+) channel trafficking. PMID:26902968

  14. Haemolysis after Amplatzer device closure of ventricular septal defect

    PubMed Central

    Mulvaney, S; Grech, V

    2007-01-01

    Over the last few years, a vast variety of devices have been developed to close various septal defects through the transcatheter route. Haemolysis has been documented after Amplatzer device closure of patent ductus arteriousus, atrial septal defect, and ventricular septal defect. We report one patient with self-limiting haemolysis after implantation of an Amplatzer perimembranous VSD device. PMID:22368673

  15. Electronic circuit detects left ventricular ejection events in cardiovascular system

    NASA Technical Reports Server (NTRS)

    Gebben, V. D.; Webb, J. A., Jr.

    1972-01-01

    Electronic circuit processes arterial blood pressure waveform to produce discrete signals that coincide with beginning and end of left ventricular ejection. Output signals provide timing signals for computers that monitor cardiovascular systems. Circuit operates reliably for heart rates between 50 and 200 beats per minute.

  16. Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology

    PubMed Central

    Krishnamoorthi, Shankarjee; Perotti, Luigi E.; Borgstrom, Nils P.; Ajijola, Olujimi A.; Frid, Anna; Ponnaluri, Aditya V.; Weiss, James N.; Qu, Zhilin; Klug, William S.; Ennis, Daniel B.; Garfinkel, Alan

    2014-01-01

    We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations. PMID:25493967

  17. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545...

  18. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545...

  19. Capecitabine-induced ventricular fibrillation arrest: Possible Kounis syndrome.

    PubMed

    Kido, Kazuhiko; Adams, Val R; Morehead, Richard S; Flannery, Alexander H

    2016-04-01

    We report the case of capecitabine-induced ventricular fibrillation arrest, possibly secondary to type I Kounis syndrome. A 47-year-old man with a history of T3N1 moderately differentiated adenocarcinoma of the colon, status-post sigmoid resection, was started on adjuvant capecitabine approximately five months prior to presentation of cardiac arrest secondary to ventricular fibrillation. An electrocardiogram (EKG) revealed ST segment elevation on the lateral leads and the patient was taken emergently to the cardiac catheterization laboratory. The catheterization revealed no angiographically significant stenosis and coronary artery disease was ruled out. After ruling out other causes of cardiac arrest, the working diagnosis was capecitabine-induced ventricular fibrillation arrest. As such, an inflammatory work up was sent to evaluate for the possibility of a capecitabine hypersensitivity, or Kounis syndrome, and is the first documented report in the literature to do so when evaluating Kounis syndrome. Immunoglobulin E (IgE), tryptase, and C-reactive protein were normal but histamine, interleukin (IL)-6, and IL-10 were elevated. Histamine elevation supports the suspicion that our patient had type I Kounis syndrome. Naranjo adverse drug reaction probability scale indicates a probable adverse effect due to capecitabine with seven points. A case of capecitabine-induced ventricular fibrillation arrest is reported, with a potential for type 1 Kounis syndrome as an underlying pathology supported by immunologic work up. PMID:25870182

  20. Ventricular tachycardia in a patient with the "Chinese restaurant syndrome".

    PubMed

    Gann, D

    1977-07-01

    A 36-year-old man developed severe weakness, palpitation, and diaphoresis 30 minutes after eating wonton soup. On admission to the hospital he was found to have ventricular tachycardia. He was given lidocaine intravenously and the rhythm converted to normal with the three minutes. It was concluded that monosodium L-glutamate might produce potentially serious arrhythmias in susceptible persons. PMID:877655

  1. Comparison of Acute Alterations in Left Ventricular Relaxation and Diastolic Chamber Stiffness Induced by Hypoxia and Ischemia

    PubMed Central

    Serizawa, Takashi; Vogel, W. Mark; Apstein, Carl S.; Grossman, William

    1981-01-01

    To clarify conflicting reports concerning the effects of ischemia on left ventricular chamber stiffness, we compared the effects of hypoxia at constant coronary perfusion with those of global ischemia on left ventricular diastolic chamber stiffness using isolated, perfused rabbit hearts in which the left ventricle was contracting isovolumically. Since chamber volume was held constant, increases in left ventricular end diastolic pressure (LVEDP) reflected increases in chamber stiffness. At a control coronary flow rate (30 ml/min), 2 min of hypoxia and pacing tachycardia (4.0 Hz) produced major increases in postpacing LVEDP (10±1 to 24±3 mm Hg, P < 0.01) and the relaxation time constant, T, (40±4 to 224±37 ms, P < 0.001), while percent lactate extraction ratio became negative (+ 18±2 to −48±15%, P < 0.001). Coronary perfusion pressure decreased (72±5 to 52±3 mm Hg, P < 0.01), and since coronary flow was held constant, the fall in coronary perfusion pressure reflected coronary dilation and a decrease in coronary vascular resistance. Following an average of 71±6s reoxygenation and initial heart rate (2.0 Hz), LVEDP and relaxation time constant T returned to control. Hypoxia alone (without pacing tachycardia) produced similar although less marked changes (LVEDP, 10±1 to 20±3 mm Hg; and T, 32±3 to 119±22 ms; P < 0.01 for both) and there was a strong correlation between LVEDP and T (r = 0.82, P < 0.001). When a similar degree of coronary vasodilatation was induced with adenosine, no change in LVEDP occurred, indicating that the increase in end diastolic pressure observed during hypoxia was not secondary to vascular engorgement, but due to an acute effect of hypoxia on the diastolic behavior of the ventricular myocardium. In contrast, global ischemia produced by low coronary flow (12−15 ml/min) resulted in a decrease in LVEDP, as well as a marked fall in left ventricular systolic pressure. In 14 global ischemia experiments, pacing tachycardia led to a

  2. Changes in intracellular calcium concentration influence beat-to-beat variability of action potential duration in canine ventricular myocytes.

    PubMed

    Kistamas, K; Szentandrassy, N; Hegyi, B; Vaczi, K; Ruzsnavszky, F; Horvath, B; Banyasz, T; Nanasi, P P; Magyar, J

    2015-02-01

    The aim of the present work was to study the influence of changes in intracellular calcium concentration ([Ca(2+)]i) on beat-to-beat variability (short term variability, SV) of action potential duration (APD) in isolated canine ventricular cardiomyocytes. Series of action potentials were recorded from enzymatically isolated canine ventricular cells using conventional microelectrode technique. Drug effects on SV were evaluated as relative SV changes determined by plotting the drug-induced changes in SV against corresponding changes in APD and comparing these data to the exponential SV-APD function obtained with inward and outward current injections. Exposure of myocytes to the Ca(2+) chelator BAPTA-AM (5 μM) decreased, while Ca(2+) ionophore A23187 (1 μM) increased the magnitude of relative SV. Both effects were primarily due to the concomitant changes in APD. Relative SV was reduced by BAPTA-AM under various experimental conditions including pretreatment with veratridine, BAY K8644, dofetilide or E-4031. Contribution of transient changes of [Ca(2+)]i due to Ca(2+) released from the sarcoplasmic reticulum (SR) was studied using 10 μM ryanodine and 1 μM cyclopiazonic acid: relative SV was reduced by both agents. Inhibition of the Na(+)-Ca(2+) exchanger by 1 μM SEA0400 increased relative SV. It is concluded that elevation of [Ca(2+)]i increases relative SV significantly. More importantly, Ca(2+) released from the SR is an important component of this effect. PMID:25716967

  3. Clobutinol delays ventricular repolarization in the guinea pig heart: comparison with cardiac effects of HERG K+ channel inhibitor E-4031.

    PubMed

    Takahara, Akira; Sasaki, Rieko; Nakamura, Mariko; Sendo, Akiko; Sakurai, Yukiko; Namekata, Iyuki; Tanaka, Hikaru

    2009-12-01

    Clobutinol has been clinically reported to induce long QT syndrome. To clarify its cardiac electrophysiological properties, we compared effects of clobutinol on the isolated myocardium and anesthetized guinea pig heart with those of a hERG K channel blocker, E-4031. In isolated guinea pig ventricular tissues, clobutinol (3 microM) as well as E-4031 (10-100 nM) prolonged the action potential duration without affecting maximum upstroke velocity, but no further prolongation was observed after application of 30 microM clobutinol. In anesthetized closed-chest guinea pigs, clobutinol (1 and 10 mg/kg, intravenously) and E-4031 (0.01 and 1 mg/kg, intravenously) prolonged the QT interval and duration of the monophasic action potential (MAP) in a dose-dependent manner and at the same time increased the beat-to-beat variability of the MAP duration and reversed use-dependent prolongation of the MAP duration and triangulation of the MAP configuration. These results suggest that clobutinol delayed the ventricular repolarization and increased the proarrhythmic parameters linked to the hERG K channel inhibitor-induced torsade de pointes arrhythmias. PMID:19770670

  4. Molsidomine prevents post-ischaemic ventricular fibrillation in dogs.

    PubMed Central

    Cano, J. P.; Guillen, J. C.; Jouve, R.; Langlet, F.; Puddu, P. E.; Rolland, P. H.; Serradimigni, A.

    1986-01-01

    Forty anaesthetized dogs were subjected to left circumflex coronary artery ligation followed by reperfusion. Molsidomine was randomly administered to 20 dogs (50 micrograms kg-1 as an i.v. bolus - 15 min prior to coronary occlusion - followed by an infusion of 0.05 micrograms kg-1 min-1. Standard electrocardiographic leads 2 and 3 were continuously recorded to measure ST segment and delta R% changes and to document both the number of ventricular premature beats and the onset of ventricular fibrillation; aortic pressure and cardiac output were measured; thromboxane B2 plasma levels, platelet aggregation produced by ADP, and molsidomine plasma levels were determined before and at 10, 30 and 75 min after the start of the drug protocol. Molsidomine protected the treated animals from early (10 min) post-ischaemic ventricular fibrillation (0 of 20 vs 6 of 20, P = 0.0202), reduced the incidence of overall post-occlusion ventricular fibrillation (3 of 20 vs 10 of 20, P = 0.0407) and improved the total survival rate (P = 0.0067). In molsidomine treated dogs: mean aortic pressure and the rate-pressure product were lowered 10 min after the start of the drug; immediate post-occlusion (3 min) ST segment changes (0.82 +/- 0.52 vs 1.52 +/- 0.78 mV, P less than 0.025) and delta R% changes (37 +/- 50 vs 90 +/- 84%, P less than 0.025) were less marked; the number of ventricular premature beats was lowered and finally, a progressive decline of platelet aggregation produced by ADP was achieved after 75 min of drug infusion. These results were obtained in the presence of mean plasma levels of molsidomine ranging from 20 to 28 ng ml-1. The time-action curve of the antifibrillatory effect of molsidomine parallels those at the level of post-ischaemic electrocardiographic changes. Images Figure 2 PMID:3755634

  5. Circadian variation of left ventricular diastolic function in healthy people.

    PubMed Central

    Voutilainen, S.; Kupari, M.; Hippelainen, M.; Karppinen, K.; Ventila, M.

    1996-01-01

    AIM--To assess whether left ventricular function shows circadian variation in healthy people. SUBJECTS AND METHODS--10 healthy men (7) and women (3) aged 35-50 underwent M mode echocardiography of the left ventricle and Doppler velocimetry of transmitral flow at 4 h intervals over 24 h. The participants were in hospital over the study period and their diet, meal times, and sleeping hours were standardised as far as possible. MEASUREMENTS--Heart rate, blood pressure, left ventricular and atrial diameters, fractional shortening, peak early and late transmitral velocities, time from the second heart sound to the early diastolic velocity peak (relaxation time), isovolumic relaxation period, acceleration and deceleration of the early transmitral flow, atrial filling fraction. RESULTS--A circadian rhythm was observed in heart rate and blood pressure, but neither the left ventricular diameters and systolic function nor the left atrial size showed statistically significant diurnal trends. The relaxation time (mean (SD)) measured 144 (16) ms at 2 pm, 144 (21) ms at 6 pm, 149 (22) ms at 10 pm, 168 (23) ms at 2 am, 174 (28) ms at 6 am, and 151 (21) ms at 10 am (P = 0.009). Diurnal rhythms were seen also in the isovolumic relaxation period (P = 0.003) and in the acceleration of the early diastolic transmitral flow (P = 0.037); the lowest and highest values of flow acceleration were observed during the nocturnal and daytime hours, respectively. CONCLUSIONS--The Doppler indices of left ventricular filling in healthy people show diurnal changes suggestive of a circadian rhythm in the rate of left ventricular relaxation. The most likely underlying mechanism is the day-night cycle in sympathoadrenal activity. PMID:8624869

  6. [Regional right ventricular hypertrophy in hypertrophic cardiomyopathy and hypertension].

    PubMed

    Seo, T; Yokota, Y; Kumaki, T; Takarada, A; Kubo, M; Kaku, K; Toh, S; Fukuzaki, H

    1985-06-01

    The mode of right ventricular hypertrophy was assessed by two-dimensional echocardiography (2DE) for 24 patients with hypertrophic cardiomyopathy (HCM), and the results were compared with those of 51 patients with hypertension (HT). The patients with HT were categorized in four groups depending on the thickness of the interventricular septum (IVST) and left ventricular posterior wall (PWT): HT-ASH with both left ventricular hypertrophy (LVH) (IVST greater than or equal to 13 mm) and asymmetric septal hypertrophy (ASH) (IVST/PWT greater than or equal to 1.3), severe HT with LVH and without ASH, and mild HT without LVH and ASH. Anterior wall thickness (AWT), posterior wall thickness (PWT), and diaphragmatic wall thickness (DWT) of the right ventricle were obtained from 2DE in the parasternal long-axis view, the short-axis view and subxiphoid view, respectively. These were recorded on video tape, and the measurements were made on the stop frames. Right ventricular hypertrophy (RVH) was estimated by the maximal right ventricular wall thickness (max RVWT), and the ratio of the maximal and minimal thickness (max RVWT/min RVWT) was calculated to evaluate asymmetrical hypertrophy (AH) of the right ventricle (RV). The incidence of RVH (Max RVWT greater than or equal to 5 mm) and asymmetrical hypertrophy (AH) (max RVWT/min RVWT greater than or equal to 1.3) of the RV in HCM, HT-ASH and mild HT were 67% and 41%, 57% and 45%, and 15% and 11%, respectively. The incidence of RVH with AH was more frequent in patients with HCM as well as HT with ASH than in patients with HT without ASH.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:4093619

  7. Right ventricular dysfunction: an independent and incremental predictor of cardiac deaths late after acute myocardial infarction.

    PubMed

    Di Bella, Gianluca; Siciliano, Valeria; Aquaro, Giovanni D; De Marchi, Daniele; Rovai, Daniele; Carerj, Scipione; Molinaro, Sabrina; Lombardi, Massimo; Pingitore, Alessandro

    2015-02-01

    Prognostic implication of right ventricular dysfunction and infarction scar in the chronic phase of the myocardial infarction has been little analyzed. In 299 consecutive patients (age 63 ± 11 years) with >3 months old myocardial infarction, we quantified right and left ventricular volumes and ejection fractions by cine cardiac magnetic resonance, and right and left ventricular scar tissue by late gadolinium enhancement. During follow-up (median, 2.4 years) cardiac events (cardiac-related deaths or appropriate intra-cardiac defibrillator shocks) occurred in 21 patients. Right ventricular systolic dysfunction (ejection fraction lower the reference mean values-2 SD) was present in 67 patients (22 %), right ventricular late gadolinium enhancement was observed in 15 patients (5 %). After adjustment for left ventricular end-diastolic volume, wall motion score index, and global extent of late gadolinium enhancement, right ventricular dysfunction was an independent and incremental predictor of cardiac events (p = 0.0053), while right ventricular scar tissue extent was not. Right ventricular dysfunction is an independent and incremental predictor of cardiac events also in the chronic phase of the myocardial infarction. In these patients, right ventricular dysfunction does not necessarily mean right ventricular infarction scar, but likely reflects the effects of hemodynamic and biohumoral factors. PMID:25348657

  8. Left atrial appendage dysfunction in a patient with premature ventricular contractions - a risk factor for stroke?

    PubMed

    Patel, Sandeep M; Ackerman, Michael J; Asirvatham, Samuel J

    2013-01-01

    A 16-year-old female with ventricular dysfunction and frequent ventricular arrhythmia presented with a cardioembolic stroke. Prior electrophysiology study and ablation was performed for ventricular tachycardia (VT). For remaining ventricular ectopy, the patient was maintained on carvedilol and mexiletine. After one year on this regimen, she presented with an acute stroke. Transesophageal echocardiography revealed no evidence of an intracardiac or ventricular thrombus but demonstrated markedly decreased left atrial appendage (LAA) flow velocity worsened during frequent premature ventricular contractions (PVC). In the absence of atrial fibrillation (AF), the LAA dysfunction was considered secondary to the frequent PVCs and was thought to be the underlying cause for the stroke. We present this case to highlight a potential under recognized association between LAA dysfunction and ventricular arrhythmia, similar to that observed with atrioventricular dyssynchronous pacing. PMID:24086095

  9. [Correlation between QT interval, ventricular arrhythmias and left ventricular function in chronic alcoholics].

    PubMed

    Pomini, G; Gribaldo, R; Bellavere, F; Lupia, M; Sale, F; Rugna, A; Costa, L; Molfese, G

    1986-04-01

    Prolonged QT interval and arrhythmias have been reported to occur in chronic alcoholics. To investigate the role of chronic alcohol consumption in the onset of arrhythmias and the development of the preclinical left ventricular dysfunction, in a group of 12 asymptomatic chronic alcoholics with no clinical evidence of heart disease, with histologically proven hepatic damage, after a week of abstinence from alcohol, the following investigations were performed: measurements of the corrected QT interval (QTc), 24-hours Holter monitoring, systolic time intervals, M-mode echocardiograms. The results were compared to those of 10 normal subjects. Our data suggested no difference in QTc interval between chronic alcoholics and normal persons. The distribution of arrhythmias was not statistically different in the two groups, particularly frequent and complicated arrhythmias occurred in only one subject in each group. Preejection period corrected for heart rate (PEPI) was significantly longer in alcoholics (132 +/- 16 vs 119 +/- 11, p less than 0.05). All echocardiographic parameters examined were not significantly different in the two groups. On the basis of our results, our impression is that the arrhythmogenic role of alcohol, not under acute ingestion, is relatively unimportant and further studies are needed to become a definitive conclusion about subclinical alcoholic cardiomyopathy. PMID:3743931

  10. Cross sectional study of contribution of clinical assessment and simple cardiac investigations to diagnosis of left ventricular systolic dysfunction in patients admitted with acute dyspnoea.

    PubMed Central

    Gillespie, N. D.; McNeill, G.; Pringle, T.; Ogston, S.; Struthers, A. D.; Pringle, S. D.

    1997-01-01

    OBJECTIVE: To assess the comparative contribution of clinical assessment, electrocardiography, and chest radiography to the diagnosis of left ventricular systolic dysfunction in patients admitted to a general medical ward with acute dyspnoea. DESIGN: Prospective cross sectional study. SETTING: Acute medical admissions ward of a teaching hospital. SUBJECTS: 71 randomly selected patients admitted with acute dyspnoea. MAIN OUTCOME MEASURES: Sensitivity and specificity of each investigation and logistic regression analysis of each variable in identifying left ventricular systolic dysfunction. RESULTS: Clinical assessment in this cohort of patients with severe dyspnoea was generally sensitive (sensitivity 81%). Patients were divided into three groups on the basis of clinical assessment. In the first group (37 patients) the diagnosis of systolic dysfunction was clear, in the second (22) it was in doubt, and in the third (12) it was unlikely. The sensitivity of clinical assessment in identifying left ventricular systolic dysfunction was 81% and the specificity was 47%. The specificity of diagnosis was improved by electrocardiography (69%) and chest radiography (92%). Logistic regression analysis showed that isolated pulmonary crepitations were a comparatively poor predictor of left ventricular systolic dysfunction chi 2 = 10.215, P = 0.0014) but that a full clinical examination had reasonable predictive value (chi 2 = 24.82, P < 0.00001). The combination of clinical assessment and chest radiography improved the accuracy of diagnosis (chi 2 = 28.08, P < 0.00001), as did the combination of clinical assessment and electrocardiography (chi 2 = 32.41, P < 0.00001). CONCLUSION: Clinical assessment in patients admitted with acute dyspnoea is comparatively accurate. Patients with abnormal results on chest radiography, electrocardiography, and clinical examination have a high likelihood of having left ventricular systolic dysfunction. Echocardiography contributes little more to

  11. Far-field P-wave sensing by the right ventricular lead of conventional dual chamber pacemakers.

    PubMed

    Barold, S Serge; Garrigue, Stéphane; Clémenty, Jacques

    2002-02-01

    This report describes two cases of far-field sensing of the P wave by the ventricular channel of conventional DDD pacemakers programmed to a relatively high sensitivity to promote sensing of ventricular extrasystoles. Ventricular pacing was maintained in both cases when the ventricular channel was not inhibited. One case was caused by displacement of a bipolar ventricular lead towards the right ventricular inflow tract. The other case occurred only in relation to an atrial extrasystole in the absence of ventricular lead displacement. PMID:11839887

  12. Details of left ventricular radial wall motion supporting the ventricular theory of the third heart sound obtained by cardiac MR

    PubMed Central

    Robson, M D; Rider, O J; Pegg, T J; Dasanu, C A; Jung, B A; Rotaru, N; Clarke, K; Holloway, C J

    2014-01-01

    Objective: Obtaining new details of radial motion of left ventricular (LV) segments using velocity-encoding cardiac MRI. Methods: Cardiac MR examinations were performed on 14 healthy volunteers aged between 19 and 26 years. Cine images for navigator-gated phase contrast velocity mapping were acquired using a black blood segmented κ-space spoiled gradient echo sequence with a temporal resolution of 13.8 ms. Peak systolic and diastolic radial velocities as well as radial velocity curves were obtained for 16 ventricular segments. Results: Significant differences among peak radial velocities of basal and mid-ventricular segments have been recorded. Particular patterns of segmental radial velocity curves were also noted. An additional wave of outward radial movement during the phase of rapid ventricular filling, corresponding to the expected timing of the third heart sound, appeared of particular interest. Conclusion: The technique has allowed visualization of new details of LV radial wall motion. In particular, higher peak systolic radial velocities of anterior and inferior segments are suggestive of a relatively higher dynamics of anteroposterior vs lateral radial motion in systole. Specific patterns of radial motion of other LV segments may provide additional insights into LV mechanics. Advances in knowledge: The outward radial movement of LV segments impacted by the blood flow during rapid ventricular filling provides a potential substrate for the third heart sound. A biphasic radial expansion of the basal anteroseptal segment in early diastole is likely to be related to the simultaneous longitudinal LV displacement by the stretched great vessels following repolarization and their close apposition to this segment. PMID:24641347

  13. Echocardiography-guided percutaneous per-ventricular laser ablation of ventricular septum: in vivo study in a canine model.

    PubMed

    He, Guangbin; Sun, Chao; Zhang, Xiangkong; Zuo, Lei; Qin, Haiying; Zheng, Minjuan; Zhou, Xiaodong; Liu, Liwen

    2016-05-01

    Surgical myectomy and ethanol ablation are established intervention strategies for left ventricular outflow obstruction in hypertrophic cardiomyopathy. Safety and efficacy limitations of these interventions call for a minimally invasive, potentially safer, and more efficacious strategy. In this study, we aimed to evaluate the feasibility of echocardiography-guided percutaneous per-ventricular laser ablation of a ventricular septum in a canine model. Six domestic dogs were chosen for the study. A 21G needle was inserted into the right ventricle with its tip reaching the targeted basal to mid-septum, after which laser ablation was performed as follows: 1-W laser for 3 min (180 J) at the basal segment and 5 min (300 J) at middle segment of the septum, respectively. Echocardiography, blood chemistry tests, and pathology examination were performed to assess the results of laser ablation. No death or major complications, i.e., tamponade, pericardial effusion, or ventricular fibrillation, occurred. The laser-ablated areas were well demarcated in the results of the pathological examination. The diameters of the ablated regions were 4.42 ± 0.57 and 5.28 ± 0.83 mm for 3 and 5 min ablation, respectively. Pre-ablation and post-ablation, cardiac enzymes were found to increase significantly while no significant differences were found among M-mode, 2D (LVEF), pulsed-wave (PW) Doppler, and tissue Doppler imaging (TDI) measurements. Contrast echocardiography confirmed the perfusion defects in the ablated regions. Microscopically, the ablated myocardium showed coagulative changes and a sparse distribution of disappearing nuclei and an increase in eosinophil number were observed. Our study suggests that percutaneous and per-ventricular laser ablation of the septum is feasible, potentially safe and efficacious, and warrants further investigation and validation. PMID:26861985

  14. The effect of sildenafil on right ventricular remodeling in a rat model of monocrotaline-induced right ventricular failure

    PubMed Central

    Bae, Hyun Kyung; Lee, Hyeryon; Kim, Kwan Chang

    2016-01-01

    Purpose Pulmonary arterial hypertension (PAH) leads to right ventricular failure (RVF) as well as an increase in pulmonary vascular resistance. Our purpose was to study the effect of sildenafil on right ventricular remodeling in a rat model of monocrotaline (MCT)-induced RVF. Methods The rats were distributed randomly into 3 groups. The control (C) group, the monocrotaline (M) group (MCT 60 mg/kg) and the sildenafil (S) group (MCT 60 mg/kg+ sildenafil 30 mg/kg/day for 28 days). Masson Trichrome staining was used for heart tissues. Western blot analysis and immunohistochemical staining were performed. Results The mean right ventricular pressure (RVP) was significantly lower in the S group at weeks 1, 2, and 4. The number of intra-acinar arteries and the medial wall thickness of the pulmonary arterioles significantly lessened in the S group at week 4. The collagen content also decreased in heart tissues in the S group at week 4. Protein expression levels of B-cell lymphoma-2 (Bcl-2)-associated X, caspase-3, Bcl-2, interleukin (IL)-6, matrix metalloproteinase (MMP)-2, endothelial nitric oxide synthase (eNOS), endothelin (ET)-1 and ET receptor A (ERA) in lung tissues greatly decreased in the S group at week 4 according to immunohistochemical staining. According to Western blotting, protein expression levels of troponin I, brain natriuretic peptide, caspase-3, Bcl-2, tumor necrosis factor-α, IL-6, MMP-2, eNOS, ET-1, and ERA in heart tissues greatly diminished in the S group at week 4. Conclusion Sildenafil alleviated right ventricular hypertrophy and mean RVP. These data suggest that sildenafil improves right ventricular function. PMID:27462355

  15. Stimulation of ICa by basal PKA activity is facilitated by caveolin-3 in cardiac ventricular myocytes☆

    PubMed Central

    Bryant, Simon; Kimura, Tomomi E.; Kong, Cherrie H.T.; Watson, Judy J.; Chase, Anabelle; Suleiman, M. Saadeh; James, Andrew F.; Orchard, Clive H.

    2014-01-01

    L-type Ca channels (LTCC), which play a key role in cardiac excitation–contraction coupling, are located predominantly at the transverse (t-) tubules in ventricular myocytes. Caveolae and the protein caveolin-3 (Cav-3) are also present at the t-tubules and have been implicated in localizing a number of signaling molecules, including protein kinase A (PKA) and β2-adrenoceptors. The present study investigated whether disruption of Cav-3 binding to its endogenous binding partners influenced LTCC activity. Ventricular myocytes were isolated from male Wistar rats and LTCC current (ICa) recorded using the whole-cell patch-clamp technique. Incubation of myocytes with a membrane-permeable peptide representing the scaffolding domain of Cav-3 (C3SD) reduced basal ICa amplitude in intact, but not detubulated, myocytes, and attenuated the stimulatory effects of the β2-adrenergic agonist zinterol on ICa. The PKA inhibitor H-89 also reduced basal ICa; however, the inhibitory effects of C3SD and H-89 on basal ICa amplitude were not summative. Under control conditions, myocytes stained with antibody against phosphorylated LTCC (pLTCC) displayed a striated pattern, presumably reflecting localization at the t-tubules. Both C3SD and H-89 reduced pLTCC staining at the z-lines but did not affect staining of total LTCC or Cav-3. These data are consistent with the idea that the effects of C3SD and H-89 share a common pathway, which involves PKA and is maximally inhibited by H-89, and suggest that Cav-3 plays an important role in mediating stimulation of ICa at the t-tubules via PKA-induced phosphorylation under basal conditions, and in response to β2-adrenoceptor stimulation. PMID:24412535

  16. Oxidative Stress Induced Ventricular Arrhythmia and Impairment of Cardiac Function in Nos1ap Deleted Mice.

    PubMed

    Sugiyama, Koji; Sasano, Tetsuo; Kurokawa, Junko; Takahashi, Kentaro; Okamura, Tadashi; Kato, Norihiro; Isobe, Mitsuaki; Furukawa, Tetsushi

    2016-05-25

    Genome-wide association study has identified that the genetic variations at NOS1AP (neuronal nitric oxide synthase-1 adaptor protein) were associated with QT interval and sudden cardiac death (SCD). However, the mechanism linking a genetic variant of NOS1AP and SCD is poorly understood. We used Nos1ap knockout mice (Nos1ap(-/-)) to determine the involvement of Nos1ap in SCD, paying special attention to oxidative stress.At baseline, a surface electrocardiogram (ECG) and ultrasound echocardiography (UCG) showed no difference between Nos1ap(-/-) and wild-type (WT) mice. Oxidative stress was induced by a single injection of doxorubicin (Dox, 25 mg/kg). After Dox injection, Nos1ap(-/-) showed significantly higher mortality than WT (93.3 versus 16.0% at day 14, P < 0.01). ECG showed significantly longer QTc in Nos1ap(-/-) than WT, and UCG revealed significant reduction of fractional shortening (%FS) only in Nos1ap(-/-) after Dox injection. Spontaneous ventricular tachyarrhythmias were documented by telemetry recording after Dox injection only in Nos1ap(-/-). Ex vivo optical mapping revealed that the action potential duration (APD)90 was prolonged at baseline in Nos1ap(-/-), and administration of Dox lengthened APD90 more in Nos1ap(-/-) than in WT. The expression of Bnp and the H2O2 level were higher in Nos1ap(-/-) after Dox injection. Nos1ap(-/-) showed a reduced amplitude of calcium transient in isolated cardiomyocytes after Dox injection. Administration of the antioxidant N-acetyl-L-cysteine significantly reduced mortality of Nos1ap(-/-) by Dox injection, accompanied by prevention of QT prolongation and a reduction in %FS.Although Nos1ap(-/-) mice have apparently normal hearts, oxidative stress evokes ventricular tachyarrhythmia and heart failure, which may cause sudden cardiac death. PMID:27170476

  17. Altered Na/Ca exchange distribution in ventricular myocytes from failing hearts.

    PubMed

    Gadeberg, Hanne C; Bryant, Simon M; James, Andrew F; Orchard, Clive H

    2016-01-15

    In mammalian cardiac ventricular myocytes, Ca efflux via Na/Ca exchange (NCX) occurs predominantly at T tubules. Heart failure is associated with disrupted t-tubular structure, but its effect on t-tubular function is less clear. We therefore investigated t-tubular NCX activity in ventricular myocytes isolated from rat hearts ∼18 wk after coronary artery ligation (CAL) or corresponding sham operation (Sham). NCX current (INCX) and l-type Ca current (ICa) were recorded using the whole cell, voltage-clamp technique in intact and detubulated (DT) myocytes; intracellular free Ca concentration ([Ca]i) was monitored simultaneously using fluo-4. INCX was activated and measured during application of caffeine to release Ca from sarcoplasmic reticulum (SR). Whole cell INCX was not significantly different in Sham and CAL myocytes and occurred predominantly in the T tubules in Sham myocytes. CAL was associated with redistribution of INCX and ICa away from the T tubules to the cell surface and an increase in t-tubular INCX/ICa density from 0.12 in Sham to 0.30 in CAL myocytes. The decrease in t-tubular INCX in CAL myocytes was accompanied by an increase in the fraction of Ca sequestered by SR. However, SR Ca content was not significantly different in Sham, Sham DT, and CAL myocytes but was significantly increased by DT of CAL myocytes. In Sham myocytes, there was hysteresis between INCX and [Ca]i, which was absent in DT Sham but present in CAL and DT CAL myocytes. These data suggest altered distribution of NCX in CAL myocytes. PMID:26566728

  18. Stimulation of ICa by basal PKA activity is facilitated by caveolin-3 in cardiac ventricular myocytes.

    PubMed

    Bryant, Simon; Kimura, Tomomi E; Kong, Cherrie H T; Watson, Judy J; Chase, Anabelle; Suleiman, M Saadeh; James, Andrew F; Orchard, Clive H

    2014-03-01

    L-type Ca channels (LTCC), which play a key role in cardiac excitation-contraction coupling, are located predominantly at the transverse (t-) tubules in ventricular myocytes. Caveolae and the protein caveolin-3 (Cav-3) are also present at the t-tubules and have been implicated in localizing a number of signaling molecules, including protein kinase A (PKA) and β2-adrenoceptors. The present study investigated whether disruption of Cav-3 binding to its endogenous binding partners influenced LTCC activity. Ventricular myocytes were isolated from male Wistar rats and LTCC current (ICa) recorded using the whole-cell patch-clamp technique. Incubation of myocytes with a membrane-permeable peptide representing the scaffolding domain of Cav-3 (C3SD) reduced basal ICa amplitude in intact, but not detubulated, myocytes, and attenuated the stimulatory effects of the β2-adrenergic agonist zinterol on ICa. The PKA inhibitor H-89 also reduced basal ICa; however, the inhibitory effects of C3SD and H-89 on basal ICa amplitude were not summative. Under control conditions, myocytes stained with antibody against phosphorylated LTCC (pLTCC) displayed a striated pattern, presumably reflecting localization at the t-tubules. Both C3SD and H-89 reduced pLTCC staining at the z-lines but did not affect staining of total LTCC or Cav-3. These data are consistent with the idea that the effects of C3SD and H-89 share a common pathway, which involves PKA and is maximally inhibited by H-89, and suggest that Cav-3 plays an important role in mediating stimulation of ICa at the t-tubules via PKA-induced phosphorylation under basal conditions, and in response to β2-adrenoceptor stimulation. PMID:24412535

  19. Altered Na/Ca exchange distribution in ventricular myocytes from failing hearts

    PubMed Central

    Gadeberg, Hanne C.; Bryant, Simon M.; James, Andrew F.

    2015-01-01

    In mammalian cardiac ventricular myocytes, Ca efflux via Na/Ca exchange (NCX) occurs predominantly at T tubules. Heart failure is associated with disrupted t-tubular structure, but its effect on t-tubular function is less clear. We therefore investigated t-tubular NCX activity in ventricular myocytes isolated from rat hearts ∼18 wk after coronary artery ligation (CAL) or corresponding sham operation (Sham). NCX current (INCX) and l-type Ca current (ICa) were recorded using the whole cell, voltage-clamp technique in intact and detubulated (DT) myocytes; intracellular free Ca concentration ([Ca]i) was monitored simultaneously using fluo-4. INCX was activated and measured during application of caffeine to release Ca from sarcoplasmic reticulum (SR). Whole cell INCX was not significantly different in Sham and CAL myocytes and occurred predominantly in the T tubules in Sham myocytes. CAL was associated with redistribution of INCX and ICa away from the T tubules to the cell surface and an increase in t-tubular INCX/ICa density from 0.12 in Sham to 0.30 in CAL myocytes. The decrease in t-tubular INCX in CAL myocytes was accompanied by an increase in the fraction of Ca sequestered by SR. However, SR Ca content was not significantly different in Sham, Sham DT, and CAL myocytes but was significantly increased by DT of CAL myocytes. In Sham myocytes, there was hysteresis between INCX and [Ca]i, which was absent in DT Sham but present in CAL and DT CAL myocytes. These data suggest altered distribution of NCX in CAL myocytes. PMID:26566728

  20. Assessment of prevalence of left ventricular hypertrophy in hypertension.

    PubMed

    Korner, P I; Jennings, G L

    1998-06-01

    The reported prevalence of left ventricular hypertrophy (LVH) in human hypertension is much lower than that among animals with experimental hypertension. With current methods of determining left ventricular mass by M-mode echocardiography, the standard error of a single estimate is high and consequently so is the SD of the population distribution. This accounts for the large overlap in individual values of left ventricular mass index (LVMI) between hypertensive and normotensive groups. The high SD is due to the use of the cube algorithm for relating measurements made in a single plane to the whole left ventricle, and to the difference between actual and assumed left ventricular geometries. These are not problems with nuclear magnetic resonance imaging, which provides information about the entire left ventricle without assumptions about geometry. M-mode echocardiography is well suited for estimating differences between mean LVMI values for groups of subjects but it underestimates the prevalence of LVH. In most series only about 30% of hypertensives have been reported to have LVH. The estimated prevalence of structural remodelling is increased to 50-60% of the same group of subjects when 'low-SD' measurements such as wall thickness and the wall thickness: internal radius ratio are employed. The estimated prevalence of LVH and remodelling is still greater with multivariate discriminant function analysis, with which it is found in about 70% of hypertensives. Overall, the data suggest that prevalence of LVH in established hypertension is high. The 30% of subjects reported to have LVH on the basis of LVMI measurements that are beyond the limits of the control group probably have the most severe changes. The inability to detect lesser grades of left ventricular remodelling reliably is due to the way LVMI is derived by echocardiography, rather than to intrinsic inaccuracies. It suggests that existing approaches should be supplemented by greater use of 'low-SD' variables

  1. Right Ventricular Apical Flattening as an Echocardiographic Screening Tool for Right Ventricular Enlargement.

    PubMed

    Buddhe, Sujatha; Ferguson, Mark; Arya, Bhawna; Soriano, Brian D

    2016-03-01

    Right ventricular dilation is a common complication after tetralogy of Fallot (TOF) repair. Traditional echocardiographic assessments are imprecise due to the RV's location and complex geometry. We propose a novel echocardiographic measurement: RV apical flattening (RVAF) as a screening tool to help identify subjects with severe RV dilation. Patients with repaired TOF who had both echocardiograms and CMR's within 6-month interval at our institution were included in the study. The RVAF was measured in the four-chamber echocardiographic view as the minor length of RV cavity at the level of RV apical endocardium. Subjects were divided into two groups (group I: RVEDVi ≥ 150 ml/m(2) and group II; RVEDVi < 150 ml/m(2)). Echocardiogram and CMR data were compared between groups. A total of 75 subjects were included in the study. Mean age was 12.8 ± 3.6 years. Group I had 36 subjects, and group II had 39 subjects. The mean RVAF was significantly higher in group I (2.7 ± 0.5 cm) compared with group II (1.7 ± 0.4 cm; p < 0.001). There was significant correlation between RVAF and RVEDVi (r = 0.81; p < 0.001). By ROC analysis, an RVAF cutoff value of 2.0 cm had 94 % sensitivity and 77 % specificity in identifying severe RV dilation (area under the curve 0.95). RVAF is a simple and effective echocardiographic screening tool to help identify severe RV dilation. In conjunction with other 2D echocardiographic parameters, this technique would help further refine echocardiography-guided patient selection for timing of CMR and pulmonary valve replacement. PMID:26667958

  2. Ventricular arrhythmias in dilated cardiomyopathy as an independent prognostic hallmark. Italian Multicenter Cardiomyopathy Study (SPIC) Group.

    PubMed

    De Maria, R; Gavazzi, A; Caroli, A; Ometto, R; Biagini, A; Camerini, F

    1992-06-01

    Prevalence and characteristics of ventricular arrhythmias (VA) on Holter monitoring were evaluated in 218 patients with invasively documented idiopathic dilated cardiomyopathy to clarify their relation to pump dysfunction, and their prognostic role. VA were observed in 205 patients (94%) and were high grade (ventricular pairs or tachycardia) in 130 (60%). No simple or multiform ventricular premature complexes were present in 88 patients (group 1; 41%), ventricular pairs in 63 (group 2; 32%), and ventricular tachycardia in 67 (group 3; 27%). Only echocardiographic right ventricular dimensions (p less than 0.05) and prevalence of VA during effort (8% in group 1, 15% in group 2, and 14% in group 3; p = 0.0005) differed significantly between groups. VA severity, and number of ventricular premature beats and tachycardia episodes were not correlated to right/left ventricular dimensions and pump function indexes. During a mean follow-up of 29 +/- 16 months, 27 patients died from cardiac events, and 16 received transplants. Three-year survival probability was lower in groups 2 (0.82) and 3 (0.81) than in group 1 (0.94). By Cox multivariate analysis, VA severity (p less than 0.01) was a major independent predictor of prognosis after markers of ventricular dysfunction such as left ventricular ejection fraction (p less than 0.001) and stroke work index (p less than 0.001). PMID:1590236

  3. [Long-term outcome of pharmacological and nonpharmacological treatment for ventricular arrhythmias].

    PubMed

    Ohnishi, S; Kasanuki, H

    2000-03-01

    Recent advances of nonpharmacological therapy such as catheter ablation and implantable cardioverter defibrillator and lessons from the Cardiac Arrhythmia Suppression Trial(CAST) have changed the strategy for ventricular arrhythmias. The safety and efficacy of radiofrequency catheter ablation of symptomatic sustained monomorphic ventricular tachycardia without structural heart disease has made ablation the firstline curative therapy. In idiopathic ventricular fibrillation such as Brugada syndrome, an implantable cardioverter defibrillator is the most effective treatment to prevent sudden cardiac death. In patients with asymptomatic ventricular tachyarrhythmias in heart failure, class I antiarrhythmic drugs should be avoided due to proarrhythmic and negative inotropic effects that may be responsible for increased mortality in some trials. In such patients, amiodarone and beta-blocker may reduce sudden cardiac death. For patients with sustained ventricular tachycardia or ventricular fibrillation in heart failure, amiodarone or implantable cardioverter defibrillator should be considered. In comparison with amiodarone, implantable cardioverter defibrillator markedly reduced sudden death in ventricular tachycardia and ventricular fibrillation survivors in Antiarrhythmics Versus Implantable Defibriltors(AVID). Although better patient selection and clarification of mapping criteria improved the successful ablation rate in patients with structural heart disease, candidates of ablation are few. In patients with extensive structural heart disease, multiple ventricular tachycardias are often present. Catheter ablation of a single ventricular tachycardia may be only palliative. Therefore, implantable cardioverter defibrillator is the most effective treatment to prevent sudden cardiac death, with amiodarone and ablation as the adjunctive therapy to prevent frequent ventricular tachycardia. Furthermore, an implantable cardioverter defibrillator improved survival in selected

  4. Left ventricular function in adults with mild pulmonary insufficiency late after Fallot repair

    PubMed Central

    Niezen, R; Helbing, W; van der Wall, E E; van der Geest, R J; Vliegen, H; de Roos, A

    1999-01-01

    OBJECTIVE—To assess left ventricular function in adult Fallot patients with residual pulmonary regurgitation.
SETTING—The radiology department of a tertiary referral centre.
PATIENTS—14 patients with chronic pulmonary regurgitation and right ventricular volume overload after repair of tetralogy of Fallot and 10 healthy subjects were studied using magnetic resonance imaging.
MAIN OUTCOME MEASURES—Biventricular volumes, global biventricular function, and regional left ventricular function were assessed in all subjects.
RESULTS—The amount of pulmonary regurgitation in patients (mean (SD)) was 25 (18)% of forward flow and correlated significantly with right ventricular enlargement (p < 0.05). Left ventricular end diastolic volume was decreased in patients (78 (11) v 88 (10) ml/m2; p < 0.05), ejection fraction was not significantly altered (59 (5)% v 55 (7)%; NS). No significant correlation was found between pulmonary regurgitation and left ventricular function. Overall left ventricular end diastolic wall thickness was significantly lower in patients (5.06 (0.72) v 6.06 (1.06) mm; p < 0.05), predominantly in the free wall. At the apical level, left ventricular systolic wall thickening was 20% higher in Fallot patients (p < 0.05). Left ventricular shape was normal.
CONCLUSIONS—Adult Fallot patients with mild chronic pulmonary regurgitation and subsequent right ventricular enlargement showed a normal left ventricular shape and global function. Although the left ventricular free wall had reduced wall thickness, compensatory hypercontractility of the apex may contribute to preserved global function.


Keywords: left ventricular function; pulmonary insufficiency; tetralogy of Fallot; magnetic resonance imaging PMID:10573497

  5. Chronic effects of myocardial infarction on right ventricular function: a noninvasive assessment

    SciTech Connect

    Kaul, S.; Hopkins, J.M.; Shah, P.M.

    1983-10-01

    To assess the chronic effects of myocardial infarction on right ventricular function, 48 subjects were studied utilizing radionuclide angiography and two-dimensional echocardiography. Ten were normal subjects (group I), 11 had previous inferior wall myocardial infarction (group II), 10 had previous anteroseptal infarction (group III), 11 had combined anteroseptal and inferior infarction (group IV) and 6 had extensive anterolateral infarction (group V). The mean (+/- standard deviation) left ventricular ejection fraction was 0.66 +/- 0.03 in group I, 0.58 +/- 0.02 in group II, 0.52 +/- 0.02 in group III, 0.33 +/- 0.03 in group IV and 0.33 +/- 0.01 in group V. No systematic correlation between left and right ventricular ejection fraction was observed among the groups. The mean right ventricular ejection fraction was significantly reduced in the presence of inferior myocardial infarction (0.30 +/- 0.03 in group II and 0.29 +/- 0.03 in group IV compared with 0.43 +/- 0.02 in group I (p less than 0.001)). The group II and IV patients also had increased (p less than 0.001) right ventricular end-diastolic area and decreased (p less than 0.001) right ventricular free wall motion by two-dimensional echocardiography. In the presence of anteroseptal infarction (group III), right ventricular free wall motion was increased (p less than 0.05) compared with normal subjects (group I). Thus, the effects of prior myocardial infarction on right ventricular function depend more on the location of infarction than on the extent of left ventricular dysfunction. Inferior infarction was commonly associated with reduced right ventricular ejection fraction and increased right ventricular end-diastolic area. The right ventricular free wall excursion was increased in the presence of anteroseptal infarction, suggested loss of contribution of interventricular septal contraction to right ventricular ejection.

  6. Intracellular signalling mechanism responsible for modulation of sarcolemmal ATP-sensitive potassium channels by nitric oxide in ventricular cardiomyocytes.

    PubMed

    Zhang, Dai-Min; Chai, Yongping; Erickson, Jeffrey R; Brown, Joan Heller; Bers, Donald M; Lin, Yu-Fung

    2014-03-01

    The ATP-sensitive potassium (KATP) channels are crucial for stress adaptation in the heart. It has previously been suggested that the function of KATP channels is modulated by nitric oxide (NO), a gaseous messenger known to be cytoprotective; however, the underlying mechanism remains poorly understood. Here we sought to delineate the intracellular signalling mechanism responsible for NO modulation of sarcolemmal KATP (sarcKATP) channels in ventricular cardiomyocytes. Cell-attached patch recordings were performed in transfected human embryonic kidney (HEK) 293 cells and ventricular cardiomyocytes freshly isolated from adult rabbits or genetically modified mice, in combination with pharmacological and biochemical approaches. Bath application of the NO donor NOC-18 increased the single-channel activity of Kir6.2/SUR2A (i.e., the principal ventricular-type KATP) channels in HEK293 cells, whereas the increase was abated by KT5823 [a selective cGMP-dependent protein kinase (PKG) inhibitor], mercaptopropionyl glycine [MPG; a reactive oxygen species (ROS) scavenger], catalase (an H2O2-degrading enzyme), myristoylated autocamtide-2 related inhibitory peptide (mAIP) selective for Ca2+ / calmodulin-dependent protein kinase II (CaMKII) and U0126 [an extracellular signal-regulated protein kinase 1/2 (ERK1/2) inhibitor], respectively. The NO donors NOC-18 and N-(2-deoxy-α,β-d-glucopyranose-2-)-N2-acetyl-S-nitroso-d,l-penicillaminamide (glycol-SNAP-2) were also capable of stimulating native sarcKATP channels preactivated by the channel opener pinacidil in rabbit ventricular myocytes, through reducing the occurrence and the dwelling time of the long closed states whilst increasing the frequency of channel opening; in contrast, all these changes were reversed in the presence of inhibitors selective for soluble guanylyl cyclase (sGC), PKG, calmodulin, CaMKII or ERK1/2. Mimicking the action of NO donors, exogenous H2O2 potentiated pinacidil-preactivated sarcKATP channel activity in

  7. Intracellular signalling mechanism responsible for modulation of sarcolemmal ATP-sensitive potassium channels by nitric oxide in ventricular cardiomyocytes

    PubMed Central

    Zhang, Dai-Min; Chai, Yongping; Erickson, Jeffrey R; Brown, Joan Heller; Bers, Donald M; Lin, Yu-Fung

    2014-01-01

    The ATP-sensitive potassium (KATP) channels are crucial for stress adaptation in the heart. It has previously been suggested that the function of KATP channels is modulated by nitric oxide (NO), a gaseous messenger known to be cytoprotective; however, the underlying mechanism remains poorly understood. Here we sought to delineate the intracellular signalling mechanism responsible for NO modulation of sarcolemmal KATP (sarcKATP) channels in ventricular cardiomyocytes. Cell-attached patch recordings were performed in transfected human embryonic kidney (HEK) 293 cells and ventricular cardiomyocytes freshly isolated from adult rabbits or genetically modified mice, in combination with pharmacological and biochemical approaches. Bath application of the NO donor NOC-18 increased the single-channel activity of Kir6.2/SUR2A (i.e. the principal ventricular-type KATP) channels in HEK293 cells, whereas the increase was abated by KT5823 [a selective cGMP-dependent protein kinase (PKG) inhibitor], mercaptopropionyl glycine [MPG; a reactive oxygen species (ROS) scavenger], catalase (an H2O2-degrading enzyme), myristoylated autocamtide-2 related inhibitory peptide (mAIP) selective for Ca2+/calmodulin-dependent protein kinase II (CaMKII) and U0126 [an extracellular signal-regulated protein kinase 1/2 (ERK1/2) inhibitor], respectively. The NO donors NOC-18 and N-(2-deoxy-α,β-d-glucopyranose-2-)-N2-acetyl-S-nitroso-d,l-penicillaminamide (glycol-SNAP-2) were also capable of stimulating native sarcKATP channels preactivated by the channel opener pinacidil in rabbit ventricular myocytes, through reducing the occurrence and the dwelling time of the long closed states whilst increasing the frequency of channel opening; in contrast, all these changes were reversed in the presence of inhibitors selective for soluble guanylyl cyclase (sGC), PKG, calmodulin, CaMKII or ERK1/2. Mimicking the action of NO donors, exogenous H2O2 potentiated pinacidil-preactivated sarcKATP channel activity in

  8. Hemodynamic-impact-based prioritization of ventricular tachycardia alarms.

    PubMed

    Desai, Kalpit; Lexa, Michael; Matthews, Brett; Genc, Sahika

    2014-01-01

    Ventricular tachycardia (V-tach) is a very serious condition that occurs when the ventricles are driven at high rates. The abnormal excitation pathways make ventricular contraction less synchronous resulting in less effective filling and emptying of the left ventricles. However, almost half of the V-tach alarms declared through processing of patterns observed in electrocardiography are not clinically actionable. The focus of this study is to provide guidance on determining whether a technically-correct V-tach alarm is clinically-actionable by determining its "hemodynamic impact". A supervisory learning approach based on conditional inference trees to determine the hemodynamic impact of a V-tach alarm based on extracted features is described. According to preliminary results on a subset of Multiparameter intelligent monitoring in intensive care II (MIMIC-II) database, true positive rate of more than 90% can be achieved. PMID:25570734

  9. Right Heart Vortex Entrainment Volume and Right Ventricular Diastolic Dysfunction

    NASA Astrophysics Data System (ADS)

    Browning, James; Hertzberg, Jean; Fenster, Brett; Schroeder, Joyce

    2014-11-01

    Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for the 3-dimensional characterization of blood flow in the right ventricle (RV) and right atrium (RA). In this study, we investigate and quantify differences in the characteristics of coherent rotating flow structures (vortices) in the RA and RV between subjects with right ventricular diastolic dysfunction (RVDD) and normal controls. Fifteen RVDD subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine RVDD stage as well as pulmonary artery systolic pressure (PASP). CMR data was used for RA and RV vortex quantification and visualization during early and late ventricular diastole. RA and RV vortex entrainment volume is quantified and visualized using the Lambda-2 criterion, and the results are compared between healthy subjects and those with RVDD. The resulting trends are discussed and hypotheses are presented regarding differences in vortex characteristics between healthy and RVDD subjects cohorts.

  10. Right Heart Vorticity and Right Ventricular Diastolic Dysfunction

    NASA Astrophysics Data System (ADS)

    Browning, James; Hertzberg, Jean; Fenster, Brett; Schroeder, Joyce

    2015-11-01

    Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for the 3-dimensional characterization of blood flow in the right ventricle (RV) and right atrium (RA). In this study, we investigate and quantify differences in the characteristics of coherent rotating flow structures (vortices) in the RA and RV between subjects with right ventricular diastolic dysfunction (RVDD) and normal controls. Fifteen RVDD subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine RVDD stage as well as pulmonary artery systolic pressure (PASP). CMR data was used for RA and RV vortex quantification and visualization during early ventricular diastole and the results are compared between healthy subjects and those with RVDD. The resulting trends are discussed and hypotheses are presented regarding differences in vortex characteristics between healthy and RVDD subjects cohorts.

  11. T Wave Alternans And Ventricular Tachyarrhythmia Risk Stratification: A Review

    PubMed Central

    Takagi, Masahiko; Yoshikawa, Junichi

    2003-01-01

    Sudden cardiac death (SCD) is one of the leading causes of mortality in industrialized countries. Thus, identifying patients at high risk of SCD is an important goal. T wave alternans (TWA) is a new method for identifying patients with lethal ventricular tachyarrhythmias, and is dependent on heart rate. The maximal predictive accuracy is achieved at heart rates between 100 and 120 bpm, so that TWA is usually measured during exercise, phamacological stress, or atrial pacing. It has been shown that TWA has high sensitivity and negative predictive value for predicting SCD after myocardial infarction and is also useful for predicting SCD in patients with nonischemic cardiomyopathy. Although the implantable cardioverter defibrillator (ICD) is now the primary therapy for preventing SCD, it is difficult to identify those patients who are susceptible to lethal ventricular tachyarrhythmias for primary prevention. In the prediction of SCD, TWA can be used as a screening test of appropriate patients for further electrophysiological examination and therapy. PMID:16943959

  12. Triggered activity as a mechanism of recurrent ventricular tachycardia.

    PubMed Central

    Bhandari, A K; Hong, R A; Rahimtoola, S H

    1988-01-01

    Triggered activity was shown to be the likely mechanism of recurrent tachycardia in a 28 year old Vietnamese man. During baseline electrophysiological testing the tachycardia was induced consistently by prolonged atrial or ventricular pacing but not by premature extrastimuli. Moreover, the tachycardia coupling intervals varied directly with the cycle length of the initiating drive. Procainamide and propranolol did not suppress tachycardia, but verapamil terminated it and prevented its reinitiation. The origin of the tachycardia was localised to the left ventricular inferoapical segment and four direct current countershocks of 200 J each delivered via an electrode catheter abolished the tachycardia. During 12 months of follow up the patient was not treated with antiarrhythmic agents and the tachycardia did not recur. PMID:3370186

  13. Angiocardiographic methods for determination of left ventricular geometry and volume

    NASA Technical Reports Server (NTRS)

    Sandler, H.; Dodge, H. T.

    1974-01-01

    Methods are described for calculating left ventricular (LV) dimensions and chamber volumes from radiographic films. The use of biplane films for the calculation of LV volume and volume change is based on the assumption of an ellipsoidal geometry. Calculation of LV volumes from biplane films usually overestimated known volumes in postmortem hearts regardless of the methods used for volume calculation. The reasons for this are probably best explained by the fact that a smooth-surface ellipse is used to represent the irregular cavity of the LV chamber. LV volume calculated from data in a single plane compared favorably and closely with volumes calculated from biplane films. A table of normal values of ventricular volume established by angiographic studies is presented.

  14. Vortex Formation Time is Not an Index of Ventricular Function

    PubMed Central

    Vlachos, Pavlos P.; Little, William C.

    2015-01-01

    The diastolic intraventricular ring vortex formation and pinch-off process may provide clinically useful insights into diastolic function in health and disease. The vortex ring formation time (FT) concept, based on hydrodynamic experiments dealing with unconfined (large tank) flow, has attracted considerable attention and popularity. Dynamic conditions evolving within the very confined space of a filling, expansible ventricular chamber with relaxing and rebounding viscoelastic muscular boundaries, diverge from unconfined (large tank) flow and encompass rebounding walls’ suction and myocardial relaxation. Indeed, clinical/physiological findings seeking validation in vivo failed to support the notion that FT is an index of normal/abnormal diastolic ventricular function. Therefore, FT as originally proposed cannot and should not be utilized as such an index. Evidently, physiologically accurate models accounting for coupled hydrodynamic and (patho)physiological myocardial wall interactions with the intraventricular flow are still needed to enhance our understanding and yield diastolic function indices useful and reliable in the clinical setting. PMID:25609509

  15. Estimation of left ventricular mass in conscious dogs

    NASA Technical Reports Server (NTRS)

    Coleman, Bernell; Cothran, Laval N.; Ison-Franklin, E. L.; Hawthorne, E. W.

    1986-01-01

    A method for the assessment of the development or the regression of left ventricular hypertrophy (LVH) in a conscious instrumented animal is described. First, the single-slice short-axis area-length method for estimating the left-ventricular mass (LVM) and volume (LVV) was validated in 24 formaldehyde-fixed canine hearts, and a regression equation was developed that could be used in the intact animal to correct the sonomicrometrically estimated LVM. The LVM-assessment method, which uses the combined techniques of echocardiography and sonomicrometry (in conjunction with the regression equation), was shown to provide reliable and reproducible day-to-day estimates of LVM and LVV, and to be sensitive enough to detect serial changes during the development of LVH.

  16. Double outlet from chambers of left ventricular morphology.

    PubMed Central

    Coto, E O; Jimenez, M Q; Castaneda, A R; Rufilanchas, J J; Deverall, P B

    1979-01-01

    This series of 5 cases with double outlet of morphologically left ventricular chamber includes 4 found during a review of 1700 heart specimens (incidence 0.23%) and 1 found at operation and successfully corrected. Abnormal atrioventricular connection precluding total correction was present in the 4 anatomical cases. Clinical diagnosis may be difficult and it is suggested that axial cineangiography may make anatomical diagnosis easier. Absence of the infundibular septum and aortic laevoposition are frequent. As some cases can be surgically corrected, accurate information is required on the size of the right ventricle, the morphology and function of the atrioventricular valves, the presence, size, and position of the ventricular septal defect, and the degree and type of outflow tract obstruction. Images PMID:475930

  17. Classification of Contextual Use of Left Ventricular Ejection Fraction Assessments.

    PubMed

    Kim, Youngjun; Garvin, Jennifer; Goldstein, Mary K; Meystre, Stéphane M

    2015-01-01

    Knowledge of the left ventricular ejection fraction is critical for the optimal care of patients with heart failure. When a document contains multiple ejection fraction assessments, accurate classification of their contextual use is necessary to filter out historical findings or recommendations and prioritize the assessments for selection of document level ejection fraction information. We present a natural language processing system that classifies the contextual use of both quantitative and qualitative left ventricular ejection fraction assessments in clinical narrative documents. We created support vector machine classifiers with a variety of features extracted from the target assessment, associated concepts, and document section information. The experimental results showed that our classifiers achieved good performance, reaching 95.6% F1-measure for quantitative assessments and 94.2% F1-measure for qualitative assessments in a five-fold cross-validation evaluation. PMID:26262121

  18. Left ventricular pseudoaneurysm versus aneurysm a diagnosis dilemma

    PubMed Central

    Bisoyi, Samarjit; Dash, Anjan K.; Nayak, Debashish; Sahoo, Satyajit; Mohapatra, Raghunath

    2016-01-01

    Free wall rupture of the left ventricle (LV) is a rare but life-threatening complication of acute myocardial infaction. Very rarely such rupture may be contained by the adhering pericardium creating a pseudoaneurysm. This condition warrants for an emergency surgery. Left ventricular aneurysm is the discrete thinning of the ventricular wall (<5 mm) with akinetic or dyskinetic wall motion causing an out-pouching of the ventricle. Given the propensity for pseudoaneurysms to rupture leading to cardiac tamponade, shock, and death, compared with a more benign natural history for true aneurysms, accurate diagnosis of these conditions is important. True aneurysm, usually, calls for an elective surgery. Clinically differentiating the two conditions remains a challenge. We report the case of a patient with LV pseudoaneurysm, initially diagnosed as true aneurysm at our institution. We have attempted to review the existing literature and discussed the characteristic findings of each entity. PMID:26750696

  19. Right heart failure post left ventricular assist device implantation

    PubMed Central

    Argiriou, Mihalis; Kolokotron, Styliani-Maria; Sakellaridis, Timothy; Argiriou, Orestis; Charitos, Christos; Katsikogiannis, Nikolaos; Kougioumtzi, Ioanna; Machairiotis, Nikolaos; Tsiouda, Theodora; Tsakiridis, Kosmas; Zarogoulidis, Konstantinos

    2014-01-01

    Right heart failure (RHF) is a frequent complication following left ventricular assist device (LVAD) implantation. The incidence of RHF complicates 20-50% (range, 9-44%) of cases and is a major factor of postoperative morbidity and mortality. Unfortunately, despite the fact that many risk factors contributing to the development of RHF after LVAD implantation have been identified, it seems to be extremely difficult to avoid them. Prevention of RHF consists of the management of the preload and the afterload of the right ventricle with optimum inotropic support. The administration of vasodilators designed to reduce pulmonary vascular resistance is standard practice in most centers. The surgical attempt of implantation of a right ventricular assist device does not always resolve the problem and is not available in all cardiac surgery centers. PMID:24672699

  20. Relaxation of Isolated Ventricular Cardiomyocytes by a Voltage-Dependent Process

    NASA Astrophysics Data System (ADS)

    Bridge, John H. B.; Spitzer, Kenneth W.; Ershler, Philip R.

    1988-08-01

    Cell contraction and relaxation were measured in single voltage-clamped guinea pig cardiomyocytes to investigate the contribution of sarcolemmal Na+-Ca2+ exchange to mechanical relaxation. Cells clamped from -80 to 0 millivolts displayed initial phasic and subsequent tonic contractions; caffeine reduced or abolished the phasic and enlarged the tonic contraction. The rate of relaxation from tonic contractions was steeply voltage-dependent and was significantly slowed in the absence of a sarcolemmal Na+ gradient. Tonic contractions elicited in the absence of a Na+ gradient promptly relaxed when external Na+ was applied, reflecting activation of Na+-Ca2+ exchange. It appears that a voltage-dependent Na+-Ca2+ exchange can rapidly mechanically relax mammalian heart muscle.