... prevented by treating heart problems and avoiding certain medicines. Alternative Names Wide-complex tachycardia; V tach; Tachycardia - ventricular Images Implantable cardioverter-defibrillator ... Ventricular arrhythmias. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap ...
Francis, Johnson; Venugopal, K; Khadar, S A; Sudhayakumar, N; Gupta, Anoop K
Idiopathic fascicular ventricular tachycardia is an important cardiac arrhythmia with specific electrocardiographic features and therapeutic options. It is characterized by relatively narrow QRS complex and right bundle branch block pattern. The QRS axis depends on which fascicle is involved in the re-entry. Left axis deviation is noted with left posterior fascicular tachycardia and right axis deviation with left anterior fascicular tachycardia. A left septal fascicular tachycardia with normal axis has also been described. Fascicular tachycardia is usually seen in individuals without structural heart disease. Response to verapamil is an important feature of fascicular tachycardia. Rare instances of termination with intravenous adenosine have also been noted. A presystolic or diastolic potential preceding the QRS, presumed to originate from the Purkinje fibers can be recorded during sinus rhythm and ventricular tachycardia in many patients with fascicular tachycardia. This potential (P potential) has been used as a guide to catheter ablation. Prompt recognition of fascicular tachycardia especially in the emergency department is very important. It is one of the eminently ablatable ventricular tachycardias. Primary ablation has been reported to have a higher success, lesser procedure time and fluoroscopy time.
Iturralde Torres, P
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.
Chiarandà, G; Di Guardo, G; Gulizia, M; Lazzaro, A; Regolo, T
Fascicular tachycardia is an uncommon idiopathic ventricular tachycardia, originating from the left ventricle; it usually occurs in young male patients, with a high prevalence in south-east Asiatic people. Electrocardiographic aspects of this unique ventricular tachycardia (right bundle branch block morphology and left or right-axis deviation, with a moderate QRS widening) and verapamil sensitivity make it often difficult the differential diagnosis with other forms of supraventricular tachycardia. Reentry is believed to be the operative mechanism of fascicular tachycardia, with the reentrant circuit located in the Purkinje network, in the region of the left posterior or anterior fascicle. The slow conduction zone participating in the reentry circuit, made up of partially depolarized Purkinje fibers, seems to be located in a relatively wide area, from the basal to the apical left interventricular septum. Intravenous verapamil is elective in acute treatment; however oral verapamil shows poor efficacy in preventing tachycardia relapses. Ablative approach is very effective; success is achieved in approximately 90% of patients, with rare complications. Recently diastolic potentials during fascicular tachycardia have been reported and these findings have given rise to new electrophysiological hypotheses and new indications about the successful ablation site.
Serra, José L; Caresani, Julian A; Bono, Julio O
A 65-year-old woman was admitted to the hospital because of a syncopal episode with documented transient complete atrioventricular block. A DDD pacemaker was implanted. Post implantation, the patient was diagnosed with bidirectional ventricular tachycardia. Analysis of the arrhythmia and differential diagnosis is performed.
Taylor, G.J.; Crampton, R.S.; Gibson, R.S.; Stebbins, P.T.; Waldman, M.T.; Beller, G.A.
The prospectively assessed time course of changes in ventricular repolarization during acute myocardial infarction (AMI) is reported in 32 patients admitted 2.0 +/- 1.8 (SD) hours after AMI onset. The initial corrected QT interval (QTc) upon hospitalization was longer in the 14 patients developing ventricular tachycardia (VT) within the first 48 hours as compared to QTc in the eight patients with frequent ventricular premature beats (VPBs) and to QTc in the 10 patients with infrequent VPBs. By the fifth day after AMI onset, the QTc shortened significantly only in the VT group, suggesting a greater initial abnormality of repolarization in these patients. All 32 patients had coronary angiography, radionuclide ventriculography, and myocardial perfusion scintigraphy before hospital discharge. Significant discriminating factors related to early phase VT in AMI included initially longer QT and QTc intervals, faster heart rate, higher peak serum levels of creatine kinase, acute anterior infarction, angiographically documented proximal stenosis of the left anterior descending coronary artery, and scintigraphic evidence of hypoperfusion of the interventricular septum. Prior infarction, angina pectoris, hypertension, multivessel coronary artery disease, and depressed left ventricular ejection fraction did not provide discrimination among the three different ventricular arrhythmia AMI groups. Researchers conclude that (1) the QT interval is frequently prolonged early in AMI, (2) the initial transiently prolonged ventricular repolarization facilitates and predicts complex ventricular tachyarrhythmias within the first 48 hours of AMI, (3) jeopardized blood supply to the interventricular septum frequently coexists, and (4) therapeutic enhancement of rapid recovery of the ventricular repolarization process merits investigation for prevention of VT in AMI.
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.
Zhao, Yun-Tao; Wang, Lei; Yi, Zhong
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.
Maia, I G; Cruz Filho, F; Costa, A M; Boghossian, S H; Fagundes, M; Ribeiro, J C; Sá, R; Alves, P A
To evaluate retrospectively clinical features of repetitive monomorphic ventricular tachycardia (RMVT). Files of 11 patients with RMVT were analyzed (9 females, mean-age 37 +/- 17 years). All patients were submitted to clinical evaluation, ECG, Holter monitoring stress test, high-resolution ECG and echocardiogram; they were treated with antiarrhythmic drugs. Patients were in NYHA class I or II, 9 asymptomatics and 2 with palpitations. The ECG was normal in all of them. Cardiac memory was observed in 3. A left bundle branch block with inferior axis deviation in the frontal plane was present during RMVT in all patients (right ventricular outflow tract focus). Holter monitoring revealed mean of 12031 +/- 8345 isolated PVC/24h; 2892 +/- 234 ventricular couplets/24h and 1367 +/- 890 VTs/24h (mainly nonsustained). In 6 patients RMVT was suppressed during maximal exercise treadmill. High-resolution ECG was negative in all group. Five patients had a normal echocardiogram while 5 showed mitral valve prolapse. One patient developed tachycardiomyopathy. The arrhythmia was controlled with 320mg of oral sotalol in 3 of 4 that used this drug and with 120mg oral propranolol in one of 6 that used this drug. Drug resistance was present in the others. The mean follow-up period was 38 +/- 16 months. The results demonstrate that RMVT is a benign form of VT with no detectable anatomic substract by the currently used methods. It is probably induced by nonreentrant mechanism and frequently drug resistance is observed. Among the antiarrhythmic drugs commonly used, sotalol showed to be the most effective.
Schreiber, Doreen; Kottkamp, Hans
Idiopathic ventricular arrhythmias occur in patients without structural heart disease. They can arise from a variety of specific areas within both ventricles and in the supravalvular regions of the great arteries. Two main groups need to be differentiated: arrhythmias from the outflow tract (OT) region and idiopathic left ventricular, so-called fascicular, tachycardias (ILVTs). OT tachycardia typically originates in the right ventricular OT, but may also occur in the left ventricular OT, particularly in the sinuses of Valsalva or the anterior epicardium or the great cardiac vein. Activation mapping or pace mapping for the OT regions and mapping of diastolic potentials in ILVTs are the mapping techniques that are typically used. The ablation of idiopathic ventricular arrhythmias is highly successful, associated with only rare complications. Newly recognized entities of idiopathic ventricular tachycardias are those originating in the papillary muscles and in the atrioventricular annular regions.
Patel, Nishit H; Golwala, Harsh; Stavrakis, Stavros; Schechter, Eliot
Sertraline is a selective serotonin reuptake inhibitor, which is a commonly used drug for major depressive disorder. Most frequently reported adverse effects of sertraline in patients receiving 50-150 mg/d are dry mouth, headache, diarrhea, nausea, vomiting, sweating, and dizziness. We hereby report one of the few cases of sertraline-induced ventricular tachycardia, which has been for the first time objectively assessed by the Naranjo scale. We therefore urge the primary care physicians and the cardiologists to keep sertraline as a possible precipitating factor for evaluation of ventricular tachycardia.
Tung, Roderick; Shivkumar, Kalyanam
Epicardial mapping and ablation via a percutaneous subxiphoid technique has been instrumental in improving the working understanding of complex myocardial scars in various arrhythmogenic substrates. Endocardial ablation alone may not be sufficient in patients with ischemic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy, and Chagas disease to prevent recurrent ventricular tachycardia. Multiple observational studies have demonstrated greater freedom from recurrence with adjunctive epicardial ablation compared with endocardial ablation alone. While epicardial ablation is performed predominantly at tertiary referral centers, knowledge of the technical approach, clinical indications, and potential complications is imperative to maximizing clinical success and patient safety. In 1996, Sosa and colleagues modified the pericardiocentesis technique to enable percutaneous access to the pericardial space for mapping and catheter ablation of ventricular tachycardia.1 Originally developed for patients with epicardial scarring due to chagasic cardiomyopathy and patients with ischemic cardiomyopathy refractory to endocardial ablationm,2,3 this approach has since become an essential part of the armamentarium for the treatment of ventricular tachycardia. Myocardial scars are three-dimensionally complex with varying degrees of transmurality, and the ability to map and ablate the epicardial surface has contributed to a greater understanding of scar-related VT in postinfarction cardiomyopathy and nonischemic substrates including idiopathic dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy, and chagasic cardiomyopathy. In this review, we highlight the percutaneous approach and discuss clinical indications and potential complications. PMID:26306131
Tung, Roderick; Shivkumar, Kalyanam
Epicardial mapping and ablation via a percutaneous subxiphoid technique has been instrumental in improving the working understanding of complex myocardial scars in various arrhythmogenic substrates. Endocardial ablation alone may not be sufficient in patients with ischemic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy, and Chagas disease to prevent recurrent ventricular tachycardia. Multiple observational studies have demonstrated greater freedom from recurrence with adjunctive epicardial ablation compared with endocardial ablation alone. While epicardial ablation is performed predominantly at tertiary referral centers, knowledge of the technical approach, clinical indications, and potential complications is imperative to maximizing clinical success and patient safety. In 1996, Sosa and colleagues modified the pericardiocentesis technique to enable percutaneous access to the pericardial space for mapping and catheter ablation of ventricular tachycardia.1 Originally developed for patients with epicardial scarring due to chagasic cardiomyopathy and patients with ischemic cardiomyopathy refractory to endocardial ablationm,2,3 this approach has since become an essential part of the armamentarium for the treatment of ventricular tachycardia. Myocardial scars are three-dimensionally complex with varying degrees of transmurality, and the ability to map and ablate the epicardial surface has contributed to a greater understanding of scar-related VT in postinfarction cardiomyopathy and nonischemic substrates including idiopathic dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy, and chagasic cardiomyopathy. In this review, we highlight the percutaneous approach and discuss clinical indications and potential complications.
Le Guludec, D.; Bourguignon, M.; Sebag, C.; Valette, H.; Sirinelli, A.; Davy, J.M.; Syrota, A.; Motte, G.
Accuracy of Fourier phase mapping of radionuclide gated biventriculograms in detecting the origin of abnormal ventricular activation was studied during ventricular tachycardia or preexcitation. Group I included six patients suffering from clinical recurrent VT; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right ventricular pacing, and induced sustained VT-Group II included seven patients with Wolff-Parkinson-White syndrome and recurrent paroxysmal tachycardia; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right atrial pacing and orthodromic reciprocating tachycardia. Each acquisition lasted 5 min, in 30 degrees-40 degrees left anterior oblique projection. In Group I, the Fourier phase mapping was consistent with QRS morphology and axis during VT (5/6), except in one patient with LV aneurysm and LBBB electrical pattern during VT. Origin of VT on phase mapping was located in the right ventricle (n = 2) or in left ventricle (n = 4), at the border of wall motion abnormalities each time they existed (5/6). In Group II, the phase advance correlated with the location of the accessory pathway determined by ECG and endocardial mapping (n = 6) and per-operative epicardial mapping (n = 1). Discrimination between anterior and posterior localization of paraseptal pathways and location of intermittent preexcitation was not possible. We conclude that Fourier phase mapping is an accurate method for locating the origin of VT and determining its etiology. It can help locate the site of ventricular preexcitation in patients with only one accessory pathway; its accuracy in locating multiple accessory pathways remains unknown.
Gellér, László; Szilágyi, Szabolcs; Solymossy, Katalin; Srej, Marianna; Zima, Endre; Tahin, Tamás; Merkely, Béla
Idiopathic fascicular ventricular tachycardia is an important and not very rare cardiac arrhythmia with specific electrocardiographic features and therapeutic options. Ventricular tachycardia is characterized by relatively narrow QRS complex and right bundle branch block pattern. The QRS axis depends on which fascicle is involved in the re-entry. Left axis deviation is noted with left posterior fascicular tachycardia and right axis deviation with left anterior fascicular tachycardia. A left septal fascicular tachycardia with normal QRS axis is also possible. Idiopathic fascicular tachycardia is usually seen in individuals without structural heart disease. Response to verapamil is an important feature of fascicular tachycardia. In some cases intravenous adenosine may also terminate the arrhythmia. During electrophysiology study, presystolic or diastolic potentials precede the QRS, presumed to originate from the Purkinje fibers. The potentials can be recorded during sinus rhythm and ventricular tachycardia in many patients with fascicular tachycardia. This potential (so-called Purkinje potential) has been used as a guide to catheter ablation. Correct diagnosis of fascicular tachycardia is very important because catheter ablation is very effective in the treatment of this type of ventricular tachycardia. In this review, we describe three patients with idiopathic ventricular tachycardia and their successful catheter ablation, and summarize the actual knowledge of the diagnosis and management of this special ventricular tachycardia.
Hatzinikolaou-Kotsakou, E; Tziakas, D; Hotidis, A; Stakos, D; Floros, D; Mavridis, A; Papanas, N; Chalikias, G; Maltezos, E; Hatseras, D I
Sustained monomorphic ventricular tachycardia (SMVT) in the course of a prime acute myocardial infarction is not a common arrhythmia and its prognostic significance has not been specifically elucidated. The aim of the study was to estimate the prognostic implications of the occurrence of sustained monomorphic ventricular tachycardia in the early phase (<72 h) of a prime acute myocardial infarction. We studied 690 consecutive patients admitted to the coronary care unit with a diagnosis of a prime myocardial infarction. SMVT was observed in 18 (2.6%) patients and we followed these patients for establishing the prognostic value of the arrhythmia according to the clinical characteristics. Patients with SMVT had a more extensive myocardial infarction based on the peak of the CK-MB isoenzyme activity (480+/-290 IU/L, vs 270+/-190 IU/L, P < .01), and higher mortality rate (40% vs 9%, P < .001). The independent predictors of SMVT were CK-MB (odds ratio [OR] 12.4), presence of complex ventricular arrhythmias (OR = 5.7), a wide QRS complex > or =130 milliseconds (OR = 4.8) and Killip class (OR = 4.8). The SMVT was itself an independent predictor of mortality (OR = 5.0). Compared with patients with ventricular fibrillation or polymorphic ventricular tachycardia, those with SMVT had a higher CK-MB activity, higher rate of wide QRS > or =130 milliseconds (33% vs 8%, P < .002), had a worse hemodynamic condition (Killip class >I:58% vs 23%, P < .04) and higher recurrence rate of ischemic events (68% vs 16%, P < .05). During the one year follow-up period, 4 patients (36.3%) of the 11 survivors from those with SMVT died of cardiac related causes. SMVT during the first 72 h of a prime myocardial infarction is an index of a larger healing myocardium with acute very complexed electrophysiological changes and it is an independent predictor of in-hospital mortality and a prognostic factor of a poor one year outcome.
Mazur, Alexander; Kusniec, Jairo; Strasberg, Boris
Bundle branch reentrant (BBR) tachycardia is an uncommon form of ventricular tachycardia (VT) incorporating both bundle branches into the reentry circuit. The arrhythmia is usually seen in patients with an acquired heart disease and significant conduction system impairment, although patients with structurally normal heart have been described. Surface ECG in sinus rhythm (SR) characteristically shows intraventricular conduction defects. Patients typically present with presyncope, syncope or sudden death because of VT with fast rates frequently above 200 beats per minute. The QRS morphology during VT is a typical bundle branch block pattern, usually left bundle branch block, and may be identical to that in SR. Prolonged His-ventricular (H-V) interval in SR is found in the majority of patients with BBR VT, although some patients may have the H-V interval within normal limits. The diagnosis of BBR VT is based on electrophysiological findings and pacing maneuvers that prove participation of the His- Purkinje system in the tachycardia mechanism. Radiofrequency catheter ablation of a bundle branch can cure BBR VT and is currently regarded as the first line therapy. The technique of choice is ablation of the right bundle. The reported incidence of clinically significant conduction system impairment requiring implantation of a permanent pacemaker varies from 0% to 30%. Long-term outcome depends on the underlying cardiac disease. Patients with poor systolic left ventricular function are at risk of sudden death or death from progressive heart failure despite successful BBR VT ablation and should be considered for an implantable cardiovertor-defibrillator. PMID:16943949
Maccabelli, Giuseppe; Mizuno, Hiroya; Della Bella, Paolo
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
Kuo, C T; Luqman, N; Lin, K H; Chiang, C W
Area(s) of slow conduction are thought to be present within the reentry circuit of most clinically important ventricular tachycardia (VT). To prevent recurrence after ablation of VT late after myocardial infarction, it is desirable to localize and destroy area(s) of slow conduction "critical link" within the reentry circuit. Conventionally, they may be identified by endocardial catheter mapping, continuous electrical activity, mid-diastolic potentials, earliest endocardial activation, pace-mapping etc. However, none of these methods are very specific. Entrainment method may be used to localize the slow conduction zone of reentrant VT. Concealed entrainment is consistent with pacing at a site in the reentry circuit but may also occur at some "bystander" sites that are close to the reentry circuit but are not participating in the circuit itself. During pacing at the slow conduction area of the reentry circuit, the stimulus to QRS (S-QRS) interval should equal the electrogram to QRS (EG-QRS) interval during VT. Similarly the post-pacing interval (PPI) approximates the tachycardia cycle length. During pacing at bystander sites, the S-QRS interval may be greater, less than or equal to the EG-QRS interval, depending on the conduction time from the bystander site to the circuit. The PPI, however, always exceed the tachycardia cycle length. In conjunction with concealed entrainment, the use of diastolic potential, double potentials and continuous electrical activity enhances the prediction of radiofrequency termination of post-infarction VT.
Ramprakash, B; Jaishankar, S; Rao, Hygriv B; Narasimhan, C
Fascicular ventricular tachycardia (VT) is an idiopathic VT with right bundle branch block morphology and left-axis deviation occuring predominantly in young males. Fascicular tachycardia has been classified into three subtypes namely, left posterior fascicular VT, left anterior fascicular VT and upper septal fascicular VT. The mechanism of this tachycardia is believed to be localized reentry close to the fascicle of the left bundle branch. The reentrant circuit is composed of a verapamil sensitive zone, activated antegradely during tachycardia and the fast conduction Purkinje fibers activated retrogradely during tachycardia recorded as the pre Purkinje and the Purkinje potentials respectively. Catheter ablation is the preferred choice of therapy in patients with fascicular VT. Ablation is carried out during tachycardia, using conventional mapping techniques in majority of the patients, while three dimensional mapping and sinus rhythm ablation is reserved for patients with nonmappable tachycardia.
... myocytes. During exercise or emotional stress, impaired calcium regulation in the heart can lead to ventricular tachycardia ... mechanisms of arrhythmias associated to impaired Ca(2+) regulation. Heart Rhythm. 2009 Nov;6(11):1652-9. ...
Palaniswamy, Chandrasekar; Miller, Marc A; Reddy, Vivek Y; Dukkipati, Srinivas R
This review discusses the role of hemodynamic support for catheter ablation of unstable ventricular tachycardia, using commercially available mechanical circulatory support devices (intra-aortic balloon pump, Impella, TandemHeart, extracorporeal membrane oxygenation) and analyzes the published clinical experience of the safety and efficacy of these devices during ventricular tachycardia ablation. Appropriate selection of patients, device-specific characteristics, and hemodynamic monitoring is also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.
Chakraborty, Praloy; Kaul, Bhavna; Mandal, Kausik; Isser, H.S.; Bansal, Sandeep; Subramanian, Anandaraja
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. PMID:27479206
Velázquez-Rodríguez, Enrique; Rodríguez-Piña, Horacio; Pacheco-Bouthillier, Alex; Deras-Mejía, Luz María
A 12-year-old girl with symptoms of fatigue, decreased exercise tolerance and progressive dyspnea (New York Heart Association functional class III) with a possible diagnosis of dilated cardiomyopathy secondary to viral myocarditis. Because of incessant wide QRS tachycardia refractory to antiarrhythmic drugs, she was referred for electrophysiological study. The diagnosis was idiopathic left ventricular tachycardia involving the posterior fascicle of the left bundle branch. After successful treatment with radiofrequency catheter ablation guided by a Purkinje potential radiological and echocardiographic evaluation showed complete reversal of left ventricular function in the first 3 months and no recurrence of arrhythmia during 2 years of follow up.
Obeyesekere, Manoj N; Sy, Raymond W; Leong-Sit, Peter; Gula, Lorne J; Yee, Raymond; Skanes, Allan C; Klein, George J; Krahn, Andrew D
Catecholaminergic polymorphic ventricular tachycardia is a rare genetic disorder caused by mutations in genes involved in the intracellular calcium homeostasis of cardiac cells. Affected patients typically present with life-threatening ventricular arrhythmias precipitated by emotional/physical stress. The diagnosis is based on the demonstration of polymorphic or bidirectional ventricular tachycardia associated with adrenergic stress. Genetic testing can be confirmatory in some patients. Treatment for catecholaminergic polymorphic ventricular tachycardia includes medical and surgical efforts to suppress the effects of epinephrine at the myocardial level and/or modulation of calcium homeostasis. Mortality is high when untreated and sudden cardiac death may be the first manifestation of the disease. First-degree relatives of a proband should be offered genetic testing if the causal mutation is known. If the family mutation is not known, relatives should be clinically evaluated with provocative testing. In the absence of rigorous trials, prophylactic treatment of the asymptomatic catecholaminergic polymorphic ventricular tachycardia patient appears to reduce morbidity and mortality.
Wang, Jun; Chen, Jie
In this paper, the symbolic dynamics analysis was used to analyze the complexity of normal heartbeat signal (NSR), Ventricular tachycardia (VT) and ventricular fibrillation (VF) signals. By calculating the information entropy value of symbolic sequences, the complexities were quantified. Based on different information entropy values, NSR, VT and VF signals were distinguished with satisfactory results. The study showed that a sudden drop of symbolic sequence’s entropy value indicated that the patients most likely entered the episode of ventricular tachycardia and this was a crucial episode for the clinical treatment of patients. It had important clinical significance for the automatic diagnosis.
Schmidt, Boris; Chun, Kyoung Ryul Julian; Kuck, Karl-Heinz; Ouyang, Feifan
Ventricular tachycardias (VT) associated with the His-Purkinje system may occur in patients with and without organic heart disease. The former may encounter bundle branch reentrant VT, a macroreentrant VT utilizing the specific conduction system. It frequently occurs in patients with preexisting conduction disturbance such as complete left bundle branch block and may be eliminated by catheter ablation of the right bundle branch. After successful ablation, patient's prognosis depends on the presence or absence of structural heart disease.In patients without structural heart disease, VT with right bundle branch block pattern and superior axis, referred to as idiopathic left ventricular tachycardia, is observed. It is a reentrant VT utilizing the posterior left fascicle and the Purkinje network. The two treatment options include antiarrhythmic drug therapy with verapamil or curative catheter ablation.Another form of ventricular arrhythmia originating in the Purkinje network is idiopathic ventricular fibrillation (IVF). Focal triggers from the right and left ventricular Purkinje network induce premature ventricular contractions inducing IVF. This is amenable to catheter ablation leading to a significant reduction in ICD (implantable cardioverter defibrillator) interventions in sudden cardiac death survivors.
Monsel, F; El Hraiech, A; Amara, W
Double tachycardia is an uncommon type of tachycardia. We report the case of a 42-year-old patient, admitted in our department for palpitations. Two types of tachycardia, narrow and wide QRS one, have been documented in the moment of palpitations. The electrophysiology study highlights an atrial flutter and a fascicular ventricular tachycardia. The patient had no recurrence of palpitations after atrial flutter ablation and medical treatment by verapamil for his ventricular tachycardia. This is the first published case combining an atrial flutter and a ventricular tachycardia.
Bohora, Shomu; Singh, Parvindar; Shah, Kaushal
A 58 year old gentleman with complaints of palpitations and documented tachycardia was found to have a dilated right atrium, right ventricle and coronary sinus, which were due to partial unroofed coronary sinus without a left superior vena cava. He had upper septal ventricular tachycardia and atrio-ventricular nodal reentrant tachycardia, which was successfully treated by radiofrequency ablation. PMID:25852246
Ajijola, Olujimi A.; Tung, Roderick; Shivkumar, Kalyanam
Advances in the treatment of myocardial infarction (MI) have improved survival after ischemic cardiac injury. Post-infarct structural and functional remodeling results in electrophysiologic substrates at risk for monomorphic ventricular tachycardia (MMVT). Characterization of this substrate using a variety of clinical and investigative tools has improved our understanding of MMVT circuits, and has accelerated the development of device and catheter-based therapies aimed at identification and elimination of this arrhythmia. This review will discuss the central role of the ischemic heart disease substrate in the development MMVT. Electrophysiologic characterization of the post-infarct myocardium using bipolar electrogram amplitudes to delineate scar border zones will be reviewed. Functional electrogram determinants of reentrant circuits such as isolated late potentials will be discussed. Strategies for catheter ablation of reentrant ventricular tachycardia, including structural and functional targets will also be examined, as will the role of the epicardial mapping and ablation in the management of recurrent MMVT. PMID:24568826
Bellmann, Barbara; Nagel, Patrick; Tscholl, Verena; Roser, Mattias; Rillig, Andreas
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.
Magalhaes, Sónia; Gonçalves, Helena; Primo, João; Sá, Ana Paula; Silva, Paula; Rosas, Rui; Gama, Vasco
Fascicular ventricular tachycardia (VT), the commonest form of idiopathic left VT, occurs more frequently in young males without structural heart disease and usually presents as paroxysmal palpitations. It is subdivided into two more common subtypes, posterior and anterior. A macro-reentrant circuit involving a considerable and variable extent of the left interventricular septum is presumed to be the underlying arrhythmogenic mechanism. A slow conduction zone with particular sensitivity to verapamil participates in the circuit and it seems that diastolic potentials (DP) represent the electrical activity in or near this zone. The fascicles of the left bundle appear to constitute part of the retrograde pathway and Purkinje potentials (PP) are assumed to represent their activation. In the present retrospective study, the authors review twelve cases of fascicular VT (ten posterior and two anterior) evaluated in the electrophysiology laboratory. Although initial induction was obtained in all patients, reproducibility was poor as a consequence of frequent contact inhibition during endocardial mapping of the left ventricle and this meant that ablation was not possible in two cases. Two cases of associated atrioventricular nodal reentrant tachycardia (AVNRT) and a case of associated atrioventricular reentrant tachycardia by a right posterior accessory pathway were documented, which suggest a correlated anatomic substrate. After ablation of the slow nodal pathway in one of the AVNRTs, fascicular VT was no longer inducible. Ablation of the fascicular VT was attempted in nine patients, at the tachycardia exit site (characterized by an early ventricular electrogram fused with a Purkinje potential) in two patients with anterior fascicular VT and in five patients with the posterior subtype, and near the slow conduction pathway (site with simultaneous recording of DP and PP) in the other two patients. The initial success rate with a single procedure was 78%, two of the ablations
Buja, G; Martini, B; Nava, A
A 51 year old woman with arrhythmogenic right ventricular dysplasia had two types of ventricular tachycardia--(a) a regular and sustained tachycardia and with normal frontal plane axis on electrocardiography and (b) an irregular non-sustained tachycardia with a leftward frontal plane axis. Changes in the QRS complex were sometimes seen during the sustained ventricular tachycardia. The clinical, electrocardiographic, and electrophysiological data were consistent with the diagnosis of two different and sometimes simultaneous tachycardias originating in the right ventricle. This case suggests a possible new mechanism for the multiform appearances of the ventricular tachycardia. PMID:3395531
Thompson, L. D.; Cohen, A. J.; Bellasis, R. M.
A 62-year-old African-American man who underwent coronary artery bypass surgery was found to have repetitive ventricular tachycardia of the "Torsade des pointes" type. The arrhythmia was resistant to bretylium, lidocaine, and pacing, but was controlled by intravenous magnesium sulfate. The recurrent attacks were abolished by a bolus of 1 g magnesium sulfate and controlled using a 1 mg/minute drip for 12 hours. This case shows the effectiveness of intravenous magnesium in controlling Torsade des pointes in postoperative coronary bypass patients. PMID:8583493
Iwa, T; Tsubota, M; Matsunaga, Y; Misaki, T
The authors reviewed the results of 42 operations for non-ischemic ventricular tachycardias, tachycardia being arrested by laser ablation in 2 cases. Right and left ventricular tachycardias were seen in 26 and 14 patients, respectively. For diagnosis, preoperative electrophysiologic study, intraoperative epicardial mapping, and "delayed" potentials were used. In 38 of 40 patients who had undergone a direct operation, a positive result was obtained; in 31 patients, a complete disappearance without applying antiarrhythmics was observed. Four patients received drug therapy which proved to be ineffective before surgery. Two patients died after surgery due to recurrent tachycardia. Out of 38 survivals, 3 died of heart failure that was not caused by recurrent tachycardia.
Benjamin, Mina M; Hayes, Kevin; Field, Michael E; Scheinman, Melvin M; Hoffmayer, Kurt S
A 73-year-old man with history of pulmonary sarcoidosis was found to have runs of non-sustained bidirectional ventricular tachycardia (BVT) with two different QRS morphologies on a Holter monitor. Cardiac magnetic resonance delayed gadolinium imaging revealed a region of patchy mid-myocardial enhancement within the left ventricular basal inferolateral myocardium. An 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed increased uptake in the same area, consistent with active sarcoid, with no septal involvement. Follow-up FDG-PET one year later showed disease progression with new septal involvement. Cardiac sarcoidosis, characterized by myocardial inflammation and interstitial fibrosis that can lead to conduction system disturbance and macro re-entrant arrhythmias, should be considered in differential diagnosis of BVT. BVT may indicate septal involvement with sarcoidosis before the lesions are large enough to be detected radiologically.
Waśniewski, Michał; Ochotny, Romuald; Klotzka, Aneta; Straburzyńska-Migaj, Ewa; Grajek, Stefan
It is described a case of an 18 years old woman admitted to the hospital with tachycardia 160/min. Drugs routinely used for supraventricular arrhythmias and cardioversion were ineffective. Patient were transferred to the reference center. Based on careful ECG examination diagnosis was established as fascicular tachycardia. Verapamil given intravenously stopped tachycardia immediately. Location of reentry circuit within left ventricle and differential diagnosis of fascicular tachycardia as well as ECG features are described in discussion.
Deng, Yi; Naeini, Payam S; Razavi, Mehdi; Collard, Charles D; Tolpin, Daniel A; Anton, James M
Radiofrequency catheter ablation is increasingly being used to treat patients who have ventricular tachycardia, and anesthesiologists frequently manage their perioperative care. This narrative review is intended to familiarize anesthesiologists with preprocedural, intraprocedural, and postprocedural implications of this ablation. Ventricular tachycardia typically arises from structural heart disease, most often from scar tissue after myocardial infarction. Many patients thus affected will benefit from radiofrequency catheter ablation in the electrophysiology laboratory to ablate the foci of arrhythmogenesis. The pathophysiology of ventricular tachycardia is complex, as are the technical aspects of mapping and ablating these arrhythmias. Patients often have substantial comorbidities and tenuous hemodynamic status, necessitating pharmacologic and mechanical cardiopulmonary support. General anesthesia and monitored anesthesia care, when used for sedation during ablation, can lead to drug interactions and side effects in the presence of ventricular tachycardia, so anesthesiologists should also be aware of potential perioperative complications. We discuss variables that can help anesthesiologists safely guide patients through the challenges of radiofrequency catheter ablation of ventricular tachycardia.
Tejera-Jurado, Luis Carlos; Nava, Santiago; Colín-Lizalde, Luis; Márquez, Manlio F; Gómez-Flores, Jorge; González-Hermosillo, Jesús Antonio; Iturralde-Torres, Pedro
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.
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
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
Ventricular tachycardia (VT) is a leading cause of morbidity and mortality for many patients, with a significant emotional and economic burden caused by implantable cardioverter-defibrillator (ICD) shocks and the requirement of medication with significant side effects. Additionally, 10% of VT occurs in patients with no structural heart disease. Until quite recently, ablation for VT has been reserved as the procedure of last hope for those who have ongoing recurrences despite maximal medical therapy and who are traumatized by multiple ICD shocks . However, recent advances in imaging technology and three-dimensional intracardiac mapping systems have significantly improved the safety and efficacy of VT ablation procedures. Thus, ablation for VT should no longer be reserved as a last-resort bailout procedure and should move into the realm of routine electrophysiology treatment. PMID:20948708
Liu, Yaowu; Fang, Zhen; Yang, Bing; Kojodjojo, Pipin; Chen, Hongwu; Ju, Weizhu; Cao, Kejiang; Chen, Minglong
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
B Garner, John; M Miller, John
Arriving at the correct diagnosis in cases of wide complex tachycardia remains problematic for many clinicians. In this paper, we review the historical development of criteria used to differentiate among the major diagnostic possibilities and compare the strengths and weaknesses of various differentiating algorithms. PMID:26835036
Ying, Zhi-Qiang; Chen, Miao-Yan
Isolated left ventricular noncompaction (IVNC) is a rare congenital form of cardiomyopathy. Verapamil-sensitive fascicular ventricular tachycardia is a rare arrhythmogenic condition characterized by a right bundle-branch block pattern and left-axis deviation with a relatively narrow QRS complex. We herein present the case of a patient with IVNC who presented with verapamil-sensitive fascicular ventricular tachycardia.
Joseph, Nicholas; Hofmann, James P.; Saranteas, Theodosios; Papadimos, Thomas J.
Extracorporeal life support (ECLS) is a very effective bridging therapy in patients with refractory ventricular tachycardia (VT) associated with cardiogenic shock. A moribund patient in extremis, is not amenable to optimization by standard ACC/AHA guidelines. New approaches and novel salvage techniques are necessary to improve outcomes in patients with refractory clinical settings such as malignant ventricular arrhythmias, cardiac arrest, cardiogenic shock and/or pulmonary failure until further management options are explored. Data base searches were done using key words such as ECLS, VT, cardiac arrest, VT ablation, venoarterial extra-corporeal membrane oxygenation (VA-ECMO). The use of ECLS has been described in a few case reports to facilitate VT ablation for incessant VT refractory to medical therapy. For patients with, out-of- hospital ventricular fibrillation (VF) and VT, Minnesota Resuscitation Consortium has implemented emergent advanced perfusion and reperfusion strategy, followed by coronary angiography and primary coronary intervention to improve outcome. The major indications for ECLS are cardiogenic shock related to acute myocardial infarction, myocarditis, post embolic acute cor pulmonale, drug intoxication and post cardiac arrest syndrome with the threat of multi-organ failure. ECLS permits the use of negative inotropic antiarrhythmic drug therapy, facilitates the weaning of catecholamine administration, thereby ending the vicious cycle of catecholamine driven electric storm. ECLS provides hemodynamic support during ablation procedure, while mapping and induction of VT is undertaken. ECLS provides early access to cardiac catheterization laboratory in patients with cardiac arrest due to shockable rhythm. The current evidence from literature, supports the use of ECLS to ensure adequate vital organ perfusion in patients with refractory VT. ECLS is a safe, feasible and effective therapeutic option when conventional therapies are insufficient to support
Weidenbach, Michael; Springer, Tina; Daehnert, Ingo; Klingel, Karin; Doll, Susanne; Janousek, Jan
We report an adolescent with giant cell myocarditis (GCM) mimicking tachycardia-induced cardiomyopathy. His electrocardiogram (ECG) was typical for an incessant form of fascicular ventricular tachycardia. The patient rapidly deteriorated and required support using extracorporeal membrane oxygenation (ECMO). Biopsy revealed GCM with massive myocyte necrosis. He was successfully heart transplanted 6 days after admission.
Hernandez, Antonio; And Others
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)
Hernandez, Antonio; And Others
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)
Camaro, Cyril; Bos, Hans S; Smeets, Joep L R M
Three patients, one experiencing palpitations and two complaining of chest pain in stressful situations, appeared to have monomorphic wide complex tachycardia. After excluding channelopathy, structural abnormalities and ischaemia of the heart, this arrhythmia was classified as idiopathic. Symptoms disappeared in one patient after using metoprolol, a β-adrenoceptor blocker. The other two patients were treated with radiofrequency ablation of the focus from which the tachycardias arose. Idiopathic ventricular tachycardia mostly arises from the right ventricular outflow tract. The diagnosis is made upon history taking, including family history, echocardiography, 12-lead ECG, exercise testing and 24-hour Holter monitoring. The prognosis is excellent and sudden cardiac death is rarely seen.
Goli, Anil K; Koduri, Madhav; Downs, Christopher; Mackall, Judith
Idiopathic ventricular tachycardias, which occur in patients without structural heart disease, are a common entity, representing up to 10% of all ventricular tachycardias evaluated by cardiac electrophysiology services. Pregnancy can increase the incidence of various cardiac arrhythmias. Factors that can potentially promote arrhythmias in pregnancy include the effects of hormones, changes in autonomic tone, hemodynamic perturbations, hypokalemia, and underlying heart disease. Ventricular arrhythmias in pregnancy are repetitive monomorphic ventricular premature complexes and couplets that frequently originate at the right ventricular outflow tract. New onset symptomatic repetitive right ventricular outflow tract ventricular tachycardia during pregnancy has been inadequately reported in the literature. We present a case of symptomatic repetitive right ventricular outflow tract tachycardia that started during pregnancy and continued in the postpartum period, requiring curative treatment with electrophysiology study and radiofrequency ablation.
Reddy, Yeruva Madhu; Chinitz, Larry; Mansour, Moussa; Bunch, T. Jared; Mahapatra, Srijoy; Swarup, Vijay; Di Biase, Luigi; Bommana, Sudharani; Atkins, Donita; Tung, Roderick; Shivkumar, Kalyanam; Burkhardt, J. David; Ruskin, Jeremy; Natale, Andrea; Lakkireddy, Dhanunjaya
Background Data on relative safety, efficacy, and role of different percutaneous left ventricular assist devices for hemodynamic support during the ventricular tachycardia (VT) ablation procedure are limited. Methods and Results We performed a multicenter, observational study from a prospective registry including all consecutive patients (N=66) undergoing VT ablation with a percutaneous left ventricular assist devices in 6 centers in the United States. Patients with intra-aortic balloon pump (IABP group; N=22) were compared with patients with either an Impella or a TandemHeart device (non-IABP group; N=44). There were no significant differences in the baseline characteristics between both the groups. In non-IABP group (1) more patients could undergo entrainment/activation mapping (82% versus 59%; P=0.046), (2) more number of unstable VTs could be mapped and ablated per patient (1.05±0.78 versus 0.32±0.48; P<0.001), (3) more number of VTs could be terminated by ablation (1.59±1.0 versus 0.91±0.81; P=0.007), and (4) fewer VTs were terminated with rescue shocks (1.9±2.2 versus 3.0±1.5; P=0.049) when compared with IABP group. Complications of the procedure trended to be more in the non-IABP group when compared with those in the IABP group (32% versus 14%; P=0.143). Intermediate term outcomes (mortality and VT recurrence) during 12±5-month follow-up were not different between both groups. Left ventricular ejection fraction ≤15% was a strong and independent predictor of in-hospital mortality (53% versus 4%; P<0.001). Conclusions Impella and TandemHeart use in VT ablation facilitates extensive activation mapping of several unstable VTs and requires fewer rescue shocks during the procedure when compared with using IABP. PMID:24532564
Nof, Eyal; Lahat, Hadas; Constantini, Naama; Luria, David; Rosenfeld, Gail; Eldar, Michael; Pras, Elon; Glikson, Michael
We evaluated a family with 30 members, 3 of whom had incessant polymorphous and bidirectional ventricular tachycardia (VT) that was electrocardiographically similar to that described in other familial polymorphic VT series; the VT was unrelated to exercise and asymptomatic. More subtle, but morphologically similar, ventricular arrhythmias were detected in 3 other family members. Genes related to intracellular calcium transport were specifically excluded.
Dulac, Y; Brosset, P; Acar, P; Maury, P; Belin, V; Lagrange, A; Taktak, A; Villacèque, M; Delay, M
The authors report two cases of slow ventricular tachycardia presenting in the antenatal period. One foetus had anasarca at 38 weeks' gestation. After birth, improved myocardial function contributed to the rapid resorption of the effusions. The other case was well tolerated in the foetal and neonatal periods. In both cases, Holter ECG recorded an intermittent ventricular arrhythmia with salvos of sustained ventricular tachycardia with a maximum rate of 185/min, only 10% higher than the underlying sinus rhythm, disappearing on acceleration of the sinus rhythm. The aetiological investigation was negative. Therapeutic abstention was supported by the spontaneously favourable outcome after 3 and 5 months. Slow ventricular tachycardia or accelerated idioventricular rhythms are usually considered to be benign but the case with foetal anasarca suggests that they should be carefully followed up in the neonatal period. In the absence of a consensus on management, therapeutic abstention implies regular cardiological examination until the arrhythmia has disappeared.
Salimian, Samaneh; Thibault, Bernard; Finnerty, Vincent; Grégoire, Jean; Harel, François
Stress-induced dyssynchrony has been shown to be independently correlated with clinical outcomes in patients with dilated cardiomyopathy (DCM) and narrow QRS complexes. However, the extent to which stress levels affect inter- and intraventricular dyssynchrony parameters remains unknown. Ten large dogs were submitted to tachycardia-induced DCM by pacing the right ventricular apex for 3-4 weeks to reach a target ejection fraction (EF) of 35% or less. Stress was then induced in DCM dogs by administering intravenous dobutamine up to a maximum of 20 μg·kg(-1)·min(-1). Hemodynamic and ventricular dyssynchrony data were analyzed by left ventricular (LV) pressure measurements and gated blood pool SPECT (GBPS) imaging. In order to assess mechanical dyssynchrony in DCM subjects and compare it with that of 8 normal counterparts, we extracted the following data: count-based indices of LV contraction homogeneity index (CHI), entropy and phase standard deviation, and interventricular dyssynchrony index. A significant LV intraventricular dyssynchrony (CHI: 96.4 ± 1.3% in control vs 78.6% ± 10.9% in DCM subjects) resulted in an intense LV dysfunction in DCM subjects (EF: 49.5% ± 8.4% in control vs 22.6% ± 6.0% in DCM), compared to control subjects. However, interventricular dyssynchrony did not vary significantly between the two groups. Under stress, DCM subjects showed a significant improvement in ventricular functional parameters at each level (EF: 22.6% ± 6.0% at rest vs 48.1% ± 5.8% at maximum stress). All intraventricular dyssynchrony indices showed a significant increase in magnitude of synchrony from baseline to stress levels of greater than or equal to 5 μg·kg(-1)·min(-1) dobutamine. There were individual differences in the magnitude and pattern of change in interventricular dyssynchrony during the various levels of stress. Based on GBPS analyses, different levels of functional stress, even in close intervals, can have a significant impact on
Naeini, Payam S.; Razavi, Mehdi; Collard, Charles D.; Tolpin, Daniel A.; Anton, James M.
Radiofrequency catheter ablation is increasingly being used to treat patients who have ventricular tachycardia, and anesthesiologists frequently manage their perioperative care. This narrative review is intended to familiarize anesthesiologists with preprocedural, intraprocedural, and postprocedural implications of this ablation. Ventricular tachycardia typically arises from structural heart disease, most often from scar tissue after myocardial infarction. Many patients thus affected will benefit from radiofrequency catheter ablation in the electrophysiology laboratory to ablate the foci of arrhythmogenesis. The pathophysiology of ventricular tachycardia is complex, as are the technical aspects of mapping and ablating these arrhythmias. Patients often have substantial comorbidities and tenuous hemodynamic status, necessitating pharmacologic and mechanical cardiopulmonary support. General anesthesia and monitored anesthesia care, when used for sedation during ablation, can lead to drug interactions and side effects in the presence of ventricular tachycardia, so anesthesiologists should also be aware of potential perioperative complications. We discuss variables that can help anesthesiologists safely guide patients through the challenges of radiofrequency catheter ablation of ventricular tachycardia. PMID:28100967
Santilli, Roberto A; Diana, Alessia; Baron Toaldo, Marco
Electrocardiographic tracings of an English Bulldog referred for cardiogenic shock due to an orthodromic atrioventricular reciprocating tachycardia conducted with intraventricular conduction disturbance and mimicking ventricular tachycardia (VT) are presented. At admission the surface ECG showed a wide QRS complex tachycardia (WCT) that was converted to sinus rhythm using manual cardioversion (chest thump). This change revealed pre-existing right bundle branch block, and a final diagnosis of supraventricular tachycardia (SVT) with intraventricular conduction disturbance was made. Electrophysiologic study defined the SVT mechanism as an atrioventricular macroreentrant tachycardia mediated by a single mid-septal accessory pathway. The differentiation between various types of WCT is essential when antiarrhythmic therapy is considered. The surface ECG should be systematically evaluated in order to recognize the characteristic features of SVT and VT. Moreover chest thump procedure can be very helpful in the attempt to convert the rhythm to sinus rhythm and to correctly recognize the underlying arrhythmia.
Shah, Ashok J; Hocini, Meleze; Denis, Arnaud; Derval, Nicolas; Sacher, Frederic; Jais, Pierre; Haissaguerre, Michel
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. Copyright © 2016 Elsevier Inc. All rights reserved.
We present an uncommon and unique arrhythmia in a patient with non-ischemic cardiomyopathy and dual chamber implantable cardioverter defibrillator presenting with palpitations and dyspnea. While surface electrocardiogram suggested irregular narrow complex tachycardia, evaluation of stored electrograms from implantable cardioverter defibrillator revealed incessant episodes of non-sustained ventricular tachycardia. The patient underwent electrophysiological study and successful ablation of the arrhythmia with complete resolution of symptoms. We discuss the underlying tachycardia mechanism and challenges in the diagnosing and management of this unusual rhythm disorder. Copyright © 2015 Elsevier Inc. All rights reserved.
Exposito, Victor; Rodriguez-Entem, Felipe; Gonzalez-Enriquez, Susana; Olalla, Juan Jose
Sustained ventricular tachycardia (VT) is an important cause of morbidity and sudden death in patients with dilated cardiomyopathy. Although ICD effectively terminate VT episodes and improve survival, shocks reduce quality of life, and episodes of VT predict increased risk of heart failure and death despite effective therapy. Patients suffering recurrent VT episodes remain a challenge. Antiarrhytmic therapy reduces VT episodes, but it is associated with serious adverse events, and disappointing efficacy. Catheter ablation has emerged as an important option to control recurrent VT, but major procedure-related complications, and even death, are still issues to concern. And even with these armamentaria, some patients still have recurrent VT episodes and ICD shocks. We report on a patient with non-ischemic dilated cardiomyopathy and recurrent ventricular tachycardia resistant to multiple antiarrhytmic agents, in whom dronedarone was effective in completely suppressing ventricular tachycardia episodes.
Hollowell, Heather; Mattu, Amal; Perron, Andrew D; Holstege, Christopher; Brady, William J
Wide-complex tachycardia (WCT) is defined as a rhythm disturbance with a rate greater than 100 beats/min and a QRS complex duration of 0.12 seconds or more in the adult patient; in the pediatric patient, both rate and QRS complex width are age related. In evaluating this type of tachycardia, there are 2 broad categories usually discussed in the medical literature: ventricular and supraventricular with aberrant intraventricular conduction. There are several other important causes of a WCT encountered in clinical practice, which are less often discussed; these tachycardias often require specific therapies differing from the standard approach to WCT. These tachycardias are diverse; as such, the pathophysiology behind each form of WCT includes toxic, metabolic, and conduction system dysfunction mechanisms.
Stratemann, Stacy; Dzurik, Yvette; Fish, Frank; Parra, David
Cardiac tumors in children are rare. Although most are histologically benign, they can be associated with life-threatening arrhythmias and sudden death. We report a 7-year-old boy, with a first episode of symptomatic tachycardia, who was found to have a left ventricular (LV) fibroma. He had a normal echocardiogram prior to an electrophysiology study, which revealed a sustained monomorphic ventricular tachycardia and a radio-opacity near the LV apex. These findings prompted a cardiac MRI, which demonstrated a discrete mass on his LV apex and free wall. Our case emphasizes that structural heart disease should be aggressively pursued in children presenting with ventricular tachycardia.
Sheldon, Seth H; Gard, Joseph J; Asirvatham, Samuel J
Premature ventricular contractions (PVCs) and non-sustained ventricular tachycardia (NSVT) are frequently encountered and a marker of electrocardiomyopathy. In some instances, they increase the risk for sustained ventricular tachycardia, ventricular fibrillation, and sudden cardiac death. While often associated with a primary cardiomyopathy, they have also been known to cause tachycardia-induced cardiomyopathy in patients without preceding structural heart disease. Medical therapy including beta-blockers and class III anti-arrhythmic agents can be effective while implantable cardiac defibrillators (ICD) are indicated in certain patients. Radiofrequency ablation (RFA) is the preferred, definitive treatment in those patients that improve with anti-arrhythmic therapy, have tachycardia-induced cardiomyopathy, or have certain subtypes of PVCs/NSVT. We present a review of PVCs and NSVT coupled with case presentations on RFA of fascicular ventricular tachycardia, left-ventricular outflow tract ventricular tachycardia, and Purkinje arrhythmia leading to polymorphic ventricular tachycardia. PMID:20811538
Alwan, Yaqub; Cvetkovic, Zoran; Curtis, Michael
Recent studies have been performed on feature selection for diagnostics between non-ventricular rhythms and ventricular arrhythmias, or between non-ventricular fibrillation and ventricular fibrillation. However they did not assess classification directly between non-ventricular rhythms, ventricular tachycardia and ventricular fibrillation, which is important in both a clinical setting and preclinical drug discovery. In this study it is shown that in a direct multiclass setting, the selected features from these studies are not capable at differentiating between ventricular tachycardia and ventricular fibrillation. A high dimensional feature space, Fourier magnitude spectra, is proposed for classification, in combination with the structured prediction method conditional random fields. An improvement in overall accuracy, and sensitivity of every category under investigation is achieved.
Fritsch-Yelle, J. M.; Leuenberger, U. A.; D'Aunno, D. S.; Rossum, A. C.; Brown, T. E.; Wood, M. L.; Josephson, M. E.; Goldberger, A. L.
An episode of nonsustained ventricular tachycardia was recorded from a crew member during the second month aboard the MIR space station. Although asymptomatic, this cardiac event increases the concern that serious cardiac dysrhythmias may be a limiting factor during long-duration spaceflight.
Non-invasive three-dimensional localisation of arrhythmogenic foci in Wolff-Parkinson-White syndrome and in ventricular tachycardia by radionuclide ventriculography: phase analysis of double-angulated integrated single photon emission computed tomography (SPECT).
Weismüller, P; Clausen, M; Weller, R; Richter, P; Steinmann, J; Henze, E; Dormehl, I; Kochs, M; Adam, W E; Hombach, V
A new tomographic technique combined with phase analysis was used to detect premature and ectopic ventricular contraction patterns in 15 patients with Wolff-Parkinson-White syndrome and during ventricular tachycardia in seven patients. Data generated by gated single-photon emission computed tomography (SPECT) were analysed by backprojection of the Fourier coefficients, double-angulation, and integration to thick slices containing the ventricles, thus allowing visualisation of the contraction patterns in three perpendicular views. The results were compared with those of catheter mapping. In nine patients with Wolff-Parkinson-White syndrome the site of initial contraction detected was identical with the site of the accessory pathway found by catheter mapping. The sites of origin of the ventricular tachycardias determined by catheter mapping were within 3 cm of the sites detected by the new technique. This new technique seems to be a promising non-invasive method for localising ectopic ventricular activity that will considerably shorten the time required for subsequent invasive procedures. Images PMID:8461217
Gavin, Andrew R; Young, Glenn D; McGavigan, Andrew D
A 45-year old man presents with stable monomorphic ventricular tachycardia. He had previously been diagnosed with idiopathic fascicular ventricular tachycardia. Intravenous flecainide results in termination of his tachycardia but unmasks a latent type 1 Brugada ECG pattern not seen on his resting ECG. We discuss his subsequent management and the need to consider an alternative diagnosis in individuals with a Brugada type ECG pattern who present with stable monomorphic ventricular tachycardia.
Tzou, Wendy S; Tung, Roderick; Frankel, David S; Vaseghi, Marmar; Bunch, T Jared; Di Biase, Luigi; Tholakanahalli, Venkatakrishna N; Lakkireddy, Dhanunjaya; Dickfeld, Timm; Saliaris, Anastasios; Weiss, J Peter; Mathuria, Nilesh; Tedrow, Usha; Afzal, Mohammed R; Vergara, Pasquale; Nagashima, Koichi; Patel, Mehul; Nakahara, Shiro; Vakil, Kairav; Burkhardt, J David; Tseng, Chi-Hong; Natale, Andrea; Shivkumar, Kalyanam; Callans, David J; Stevenson, William G; Della Bella, Paolo; Marchlinski, Francis E; Sauer, William H
Ventricular tachycardia (VT) radiofrequency ablation has been associated with reduced VT recurrence and mortality, although it is typically not considered among New York Heart Association class IV (NYHA IV) heart failure patients. We compared characteristics and VT radiofrequency ablation outcomes of those with and without NYHA IV in the International VT Ablation Center Collaboration. NYHA II-IV patients undergoing VT radiofrequency ablation at 12 international centers were included. Clinical variables, VT recurrence, and mortality were analyzed by NYHA IV status using Kaplan-Meier analysis and Cox proportional hazard models. There were significant differences between NYHA IV (n=111) and NYHA II and III (n=1254) patients: NYHA IV had lower left ventricular ejection fraction; more had diabetes mellitus, kidney disease, cardiac resynchronization implantable cardioverter-defibrillator, and VT storm despite greater antiarrhythmic drug use (P<0.01). NYHA IV subjects required more hemodynamic support, were inducible for more and slower VTs, and were less likely to undergo final programmed stimulation. There was no significant difference in acute complications. In-hospital deaths, recurrent VT, and 1-year mortality were higher in the NYHA IV group, in the context of greater baseline comorbidities. Importantly, NYHA IV patients without recurrent VT had similar survival compared with NYHA II and III patients with recurrent VT (68% versus 73%). Early VT recurrence (≤30 days) was significantly associated with mortality, especially in NYHA IV patients. Despite greater baseline comorbidities, VT radiofrequency ablation can be safely performed among NYHA IV patients. Early VT recurrence is significantly associated with subsequent mortality regardless of NYHA status. Elimination of recurrent VT in NYHA IV patients may reduce mortality to a level comparable to NYHA II and III with arrhythmia recurrence. © 2017 American Heart Association, Inc.
Macintyre, Ciorsti J; Sapp, John L
The management of ventricular tachyarrhythmias has changed significantly over the past several decades. The advent of readily available implantable cardioverter defibrillators (ICDs) has had the greatest effect, with important mortality effects in patients with ventricular tachycardia and structural heart disease. ICDs have been shown to reduce sudden death in patients with ischemic and nonischemic cardiomyopathies; evidence of adverse consequences of ICD shocks, however, is mounting. In addition to the negative effects on patient-reported quality of life, anxiety, and depression, frequent ventricular arrhythmias and ICD shocks have also been associated with increased mortality. It is therefore important to identify and implement effective ventricular tachycardia-suppressive strategies. Antiarrhythmic drugs represent one such method, but are challenged by unfavourable side effect profiles and proarrhythmic risk. Catheter ablation of ventricular tachycardia is now a well-accepted intervention, which has been demonstrated to reduce recurrent arrhythmias. Questions persist regarding the optimal role for ablation compared with drug therapy. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Fukushima, Akimune; Nakai, Kenji; Matsumoto, Atsushi; Strasburger, Janette; Sugiyama, Toru
We describe polymorphic ventricular tachycardia (VT) diagnosed using fetal magnetocardiography (FMCG). The fetus of a 33-year-old Japanese female at 24 weeks of pregnancy was diagnosed as bradycardia (60 beats/min) by fetal cardiotocography (CTG). Ultrasound findings indicated a diagnosis of an atrioventricular (AV) block involving extrasystole, but FMCG revealed a polymorphic VT followed by ventricular asystole. Standard ECG immediately after cesarean section at 37 weeks of pregnancy confirmed long QT syndrome followed by nonsustained polymorphic VT and an advanced AV block with wide QRS. Echocardiography demonstrated moderate left ventricular dysfunction in the neonate requiring implantation with a permanent pacemaker.
Wijnmaalen, Adrianus P; Zeppenfeld, Katja
Radiofrequency catheter ablation (RFCA) is an important treatment modality to prevent ventricular tachycardia (VT) recurrence in patients with repaired congenital heart disease. Identification and ablation of anatomic isthmuses has improved acute ablation outcome with excellent VT-free survival in those with preserved biventricular function. Reports on RFCA for VT in patients with infiltrative disease are sparse and cardiac sarcoidosis seems to be the most prevalent cause for ventricular arrhythmia. Patients with active and ongoing inflammation are at high risk for VT recurrence. RFCA reduces the number of VT but often multiple procedures are required and long-term VT-free survival is unfavorable in those with left ventricular dysfunction.
Azevedo, Ana Isabel; Dias, Adelaide; Teixeira, Madalena; Gama Ribeiro, Vasco
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia characterized by adrenergically induced polymorphic or bidirectional ventricular tachycardia (VT). Although a rare disease, its recognition is important because of its high mortality rate when left untreated. We report an index case of a 32-year-old woman who presented with recurrent syncope. The diagnosis was confirmed by exercise-induced polymorphic ventricular premature beats and episodes of non-sustained VT, in the absence of structural heart abnormalities. She remained event free with beta-blocker therapy. CPVT is a potentially life-threatening disease and should be considered in the case of recurrent syncope, in young individuals. Diagnosis is based on clinical history and exercise testing, which is the gold standard. Therapy is mandatory in all diagnosed individuals. Exercise testing in first-degree relatives is recommended, even in the case of a mutation-negative index patient. PMID:26512332
Piers, Sebastiaan R D; Everaerts, Kimberly; van der Geest, Rob J; Hazebroek, Mark R; Siebelink, Hans-Marc; Pison, Laurent A F G; Schalij, Martin J; Bekkers, Sebastiaan C A M; Heymans, Stephane; Zeppenfeld, Katja
The relation between myocardial scar and different types of ventricular arrhythmias in patients with nonischemic dilated cardiomyopathy (NIDCM) is unknown. The purpose of this study was to analyze the effect of myocardial scar, assessed by late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR), on the occurrence and type of ventricular arrhythmia in patients with NIDCM. Consecutive patients with NIDCM who underwent LGE-CMR and implantable cardioverter-defibrillator (ICD) implantation at either of 2 centers were included. LGE was defined by signal intensity ≥35% of maximal signal intensity, subdivided into core and border zones (≥50% and 35%-50% of maximal signal intensity, respectively), and categorized according to location (basal or nonbasal) and transmurality. ICD recordings and electrocardiograms were reviewed to determine the occurrence and type of ventricular arrhythmia during follow-up. Of 87 patients (age 56 ± 13 y, 62% male, left ventricular ejection fraction 29% ± 12%), 55 (63%) had LGE (median 6.3 g, interquartile range 0.0-13.8 g). During a median follow-up of 45 months, monomorphic ventricular tachycardia (VT) occurred in 18 patients (21%) and polymorphic VT/ventricular fibrillation (VF) in 10 (11%). LGE predicted monomorphic VT (log-rank, P < .001), but not polymorphic VT/VF (log-rank, P = .40). The optimal cutoff value for the extent of LGE to predict monomorphic VT was 7.2 g (area under curve 0.84). Features associated with monomorphic VT were core extent, basal location, and area with 51%-75% LGE transmurality. Myocardial scar assessed by LGE-CMR predicts monomorphic VT, but not polymorphic VT/VF, in NIDCM. The risk for monomorphic VT is particularly high when LGE shows a basal transmural distribution and a mass ≥7.2 g. Importantly, patients without LGE on CMR remain at risk for potentially fatal polymorphic VT/VF. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Sapp, John L; Wells, George A; Parkash, Ratika; Stevenson, William G; Blier, Louis; Sarrazin, Jean-Francois; Thibault, Bernard; Rivard, Lena; Gula, Lorne; Leong-Sit, Peter; Essebag, Vidal; Nery, Pablo B; Tung, Stanley K; Raymond, Jean-Marc; Sterns, Laurence D; Veenhuyzen, George D; Healey, Jeff S; Redfearn, Damian; Roux, Jean-Francois; Tang, Anthony S L
Recurrent ventricular tachycardia among survivors of myocardial infarction with an implantable cardioverter-defibrillator (ICD) is frequent despite antiarrhythmic drug therapy. The most effective approach to management of this problem is uncertain. We conducted a multicenter, randomized, controlled trial involving patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite the use of antiarrhythmic drugs. Patients were randomly assigned to receive either catheter ablation (ablation group) with continuation of baseline antiarrhythmic medications or escalated antiarrhythmic drug therapy (escalated-therapy group). In the escalated-therapy group, amiodarone was initiated if another agent had been used previously. The dose of amiodarone was increased if it had been less than 300 mg per day or mexiletine was added if the dose was already at least 300 mg per day. The primary outcome was a composite of death, three or more documented episodes of ventricular tachycardia within 24 hours (ventricular tachycardia storm), or appropriate ICD shock. Of the 259 patients who were enrolled, 132 were assigned to the ablation group and 127 to the escalated-therapy group. During a mean (±SD) of 27.9±17.1 months of follow-up, the primary outcome occurred in 59.1% of patients in the ablation group and 68.5% of those in the escalated-therapy group (hazard ratio in the ablation group, 0.72; 95% confidence interval, 0.53 to 0.98; P=0.04). There was no significant between-group difference in mortality. There were two cardiac perforations and three cases of major bleeding in the ablation group and two deaths from pulmonary toxic effects and one from hepatic dysfunction in the escalated-therapy group. In patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite antiarrhythmic drug therapy, there was a significantly lower rate of the composite primary outcome of death, ventricular tachycardia storm, or appropriate ICD shock among
Fernández-Armenta, Juan; Berruezo, Antonio
Percutaneous pericardial access for epicardial mapping and ablation of ventricular arrhythmias has expanded considerably in recent years. After its description in patients with Chagas disease, the technique has provided relevant in-formation on the arrhythmia substrate in other cardiomyopathies and has improved the results of ablation procedures in various clinical settings. Electrocardiographic criteria proposed for the recognition of the epicardial origin of ventricular tachycardias are mainly based on analysis of the first QRS components. Ventricular activation at the epicardium has a slow initial component reflecting the transmural activation and influenced by the absence of Purkinje system in the epicardium. Various parameters (pseudodelta wave, intrinsicoid deflection and shortest RS interval) of these initial intervals predict an epicardial origin in patients with scar-related ventricular tachycardias with right bundle branch block morphology. Using the same concept, the maximum deflection index was defined for the location of idiopathic epicardial tachycardias remote from the aortic root. Electrocardiogram criteria based on the morphology of the first component of the QRS (q wave in lead I) have been proposed in patients with nonischemic cardiomyopathy. All these criteria seem to be substrate-specific and have several limitations. Other information, including type of underlying heart disease, previous failed endocardial ablation, and evidence of epicardial scar on magnetic resonance imaging, can help to plan the ablation procedure and decide on an epicardial approach. PMID:24827797
Kane, Ad; Defaye, P; Jacon, P; Mbaye, A; Machecourt, J
A 45-year-old man was hospitalized for syncope due to fascicular ventricular tachycardia degenerating into ventricular fibrillation (VF). The electrocardiogram showed an early repolarization syndrome. The arrhythmia was repetitive and disappeared after oral hydroquinidine. An implantable cardioverter-defibrillator (ICD) was implanted; subsequently, the patient was arrhythmia free at 9 months follow-up.
Iturralde, P; Juárez, U; de Micheli, A; Dorado, M; Alexánderson, E; Colín, L; Kershenovich, S; Romero, L; González Hermosillo, J A
Clinical and electrophysiological characteristics in 20 patients with clinical ventricular tachycardia and normal hearts documented by physical examination, echocardiography, and angiocardiography were analysed. There were 11 males and 9 females. All patients had sustained ventricular tachycardia without hemodynamic instability during tachycardia. A right bundle branch block morphology of ventricular tachycardia was present in 14 patients and left bundle branch block morphology in six patients. During electrophysiologic studies, ventricular tachycardia was induced in 10/15 (66%) patients. Intravenous verapamil terminated the ventricular tachycardia in 9/10 (90%) of cases. However oral verapamil not prevented recurrences. Among 14 patients on whom exercise tests were performed, only two had exercise-induced ventricular/tachycardia. Late potentials were positive in 3/14 (21%) cases and one patient died suddenly during exercise without antiarrhythmic drugs.
Williams, Conrad S P; Khatib, Sammy; Dorotan-Guevara, Maria Malaya; Snyder, Christopher S
J.V. is a 3(1/2)-year-old patient with left ventricular fascicular ventricular tachycardia that had been well controlled on verapamil for 3 years. He was taken for a transesophageal electrophysiology study prior to discontinuing medication in an attempt to induce his tachycardia. We report the use of transesophageal electrophysiology study as a noninvasive method to induce left ventricular fascicular ventricular tachycardia in a toddler.
Rumoroso, J R; Bodegas, A; Subinas, J; Montes, P M; Sanz, R; Rodrigo, D; Barrenetxea, J I
We present a 36-year-old male without overt cardiac disease who suffered, since he was 15 years old, from sustained monomorphic ventricular tachycardia of left bundle branch block with a right axis, lasting for several hours; sometimes, syncope was a clinical form of manifestation. Electrophysiologic study, twenty-four hours Holter recording, cardiac catheterization and blood analysis were not useful in order to find its etiology. Efficacy of different drugs, like Mexiletil, Amiodarone, Atenolol and Verapamil (at a dose of 240 mg/day) were tested through multistaged graded-treadmill stress-testing using the Bruce protocol. Ventricular tachycardia was suppressed by administration of Lidocaine. Oral verapamil given at a dose of 360 mg/day prevented the induction of the arrhythmia, the efficacy was tested with maximal treadmill exercise and twenty-four hours Holter recording.
Mironov, N Yu; Mironova, N A; Sokolov, S F; Mareev, Yu V; Shlevkov, N B; Saidova, M A; Stukalova, O V; Golitsyn, S P
We report a case of bundle-branch reentrant ventricular tachycardia as a first and severe manifestation of myotonic dystrophy. Progressive cardiac conduction disturbances and cardiac arrhythmias are well-known features of myotonic dystrophy, although they are commonly found in late stage of disease in patients with established diagnosis. We review clinical manifestations, diagnostics, management, and prognostic value of cardiac involvement in myotonic dystrophy.
Ho, Sara Wei-Fen; Lin, Weiqin; Chan, Koo Hui; Seow, Swee-Chong
Spontaneous coronary artery dissection is an uncommon cause of acute coronary syndrome. Diagnosis of coronary artery dissection is made on coronary angiogram and prompt revascularisation is the key in management. We present a case of coronary artery dissection with an atypical presentation of cardiac arrhythmia mimicking benign fascicular ventricular tachycardia. A high index of suspicion and early coronary angiogram allowed us to diagnose and treat this potentially life-threatening disease.
Rajesh, M. C.; Deepa, K. V.; Ramdas, E. K.
Pain physicians and anesthesiologists routinely perform stellate ganglion block for the treatment of painful upper extremity sympathetic dystrophy. Close proximity of ganglion to vascular structures warrants some expertise and training in the procedure. Off late, successful use of the technique in intractable ventricular tachyarrhythmias has come in literature. We have few cases wherein we could successfully ablate intractable ventricular tachycardia with stellate block which was refractory to repeated shocks. We are reporting one such case with the intention of making an awareness in the anesthesia community about this treatment option. PMID:28298801
Behere, Shashank P; Weindling, Steven N
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly malignant inheritable cardiac channelopathy. The past decade and a half has provided exciting new discoveries elucidating the genetic etiology and pathophysiology of CPVT. This review of the current literature on CPVT aims to summarize the state of the art in our understanding of the genetic etiology and the molecular pathogenesis of CPVT, and how these relate to our current approach to diagnosis and management. We will also shed light on groundbreaking new work that will continue to refine the management of CPVT in the future. As our knowledge of CPVT continues to grow, further studies will yield a better understanding of the efficacy and pitfalls of established diagnostic approaches and therapies as well as help shape newer diagnostic and treatment strategies. Two separate searches were run on the National Center for Biotechnology Information's (NCBI) website. The first used the medical subject headings (MeSH) database using the term "catecholaminergic polymorphic ventricular tachycardia" that was run on the PubMed database using the age filter (birth to 18 years), and it yielded 58 results. The second search using the MeSH database with the search term "catecholaminergic polymorphic ventricular tachycardia," applying no filters yielded 178 results. The abstracts of all these articles were studied and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles were further explored and read in full.
Deneke, T; Israel, C W; Krug, J; Nentwich, K; Müller, P; Mügge, A; Schade, A
Ventricular tachyarrhythmias (VT) can cause sudden cardiac death. This can be prevented by an implantable cardioverter-defibrillator (ICD) but approximately 25% of patients with an ICD develop electrical storm (≥ 3 VTs within 24 hours) during the course of 4-5 years. This is a life-threatening event even in the presence of an ICD, particularly if incessant VT is present, and may significantly deteriorate the patient's psychological state if multiple shocks are discharged. Catheter ablation of VT has developed into a standard procedure in many specialized electrophysiology centers. Patients with hemodynamically stable and unstable VT are amendable to substrate-based ablation strategies. Catheter ablation can be performed as emergency procedure in patients with electrical storm as well as electively in patients with monomorphic VT stored in ICD memory. In patients with ischemic or non-ischemic cardiomyopathy, VT ablation is complementary to ICD implantation and can reduce the number of ventricular arrhythmia episodes and shocks and should be performed early. In patients with electrical storm, catheter ablation can acutely achieve rhythm stabilization and may improve prognosis in the long term. Further indications for catheter ablation exist in patients with idiopathic VT where catheter ablation represents a curative therapy, and in patients with symptomatic or asymptomatic frequent premature ventricular beats which may improve prognosis in patients with heart failure and cardiac resynchronization therapy.
Bellmann, B; Tscholl, V; Nagel, P; Roser, M
This case report describes a 31-year-old man with a sustained wide complex tachycardia with left bundle brunch block morphology after surgical repair of a tetralogy of Fallot. The tachycardia was inducible after orciprenaline administration after ventricular stimulation with one extra beat. In combination with the three-dimensional electroanatomic mapping system and pace mapping technique the origin of the tachycardia was identified at the lateral free wall of the right ventricular outflow tract tachycardia (RVOT) inferior of the pulmonary valve. Successful radiofrequency ablation was performed and the patient is still free from ventricular tachycardia.
Mann, D E; Kelly, P A; Reiter, M J
We report a patient who received a CPI Ventak AV II DR ICD for ventricular tachycardia and complete heart block without an escape rhythm. During induced nonsustained ventricular tachycardia, the device, although programmed to deliver noncommitted shocks, acted like a committed device. This phenomenon is due to undocumented behavior that is likely to occur in any patient who is pacemaker dependent and has nonsustained ventricular tachycardia.
Parizek, Petr; Popelka, Jiri; Haman, Ludek
We present a case of a 28 year old woman with paroxysmal left posterior fascicular ventricular tachycardia (LPFVT). Ventricular tachycardia was not inducible after completing of left ventricle 3D reconstruction. Even though catheter ablation was not performed, no LPFVT recurrence has been documented during 60 months follow-up. We surmise that we caused mechanical trauma during the mapping of the posterior fascicle that damaged arrhythmogenic structures and subsequently led to long term remission of the left posterior fascicular ventricular tachycardia.
Heiner, Jason D; Bullard-Berent, Jeffrey H; Inbar, Shmuel
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.
Das, Bibhuti; Cuneo, Bettina F.; Ovadia, Mark; Strasburger, Janette F.; Johnsrude, Christopher; Wakai, Ronald T.
A fetus who was diagnosed at 25 weeks of gestation with isoimmune AV block presented at 34 weeks with a precipitous fall in ventricular rate and periods of tachycardia. Magnetocardiography revealed the tachycardia to be ventricular. After delivery, nonsustained ventricular tachycardia continued. The baby then successfully paced, and at higher ventricular rates the tachycardia resolved. Five years later the child has normal ventricular function and is doing well. PMID:18765944
Das, Bibhuti; Cuneo, Bettina F; Ovadia, Mark; Strasburger, Janette F; Johnsrude, Christopher; Wakai, Ronald T
A fetus who was diagnosed at 25 weeks of gestation with isoimmune AV block presented at 34 weeks with a precipitous fall in ventricular rate and periods of tachycardia. Magnetocardiography revealed the tachycardia to be ventricular. After delivery, nonsustained ventricular tachycardia continued. The baby then successfully paced, and at higher ventricular rates the tachycardia resolved. Five years later the child has normal ventricular function and is doing well.
Hoffmann, E; Reithmann, C; Neuser, H; Nimmermann, P; Remp, T; Steinbeck, G
Repetitive monomorphic ventricular tachycardia (RMVT) is defined by the presence of numerous monomorphic isolated, premature ventricular complexes, couplets, and runs of unsustained ventricular tachycardia having the same morphology in patients without structural heart disease. Patients with RMVT mostly demonstrate the typical left bundle branch block morphology with normal or rightward axis during tachycardia. At our institution, 20 patients with RMVT have been systematically studied: a syncope had occurred in 35% of our patients, in three cases a syncope was the first manifestation of the RMVT. Of our RMVT patients, 25% developed sustained episodes (> 3 min) of ventricular tachycardia as documented by Holter ECG. The salvos of ventricular tachycardia are generally short in RMVT. This behavior and the typical exercise dependence differentiates RMVT from paroxysmal sustained idiopathic ventricular tachycardia. Exercise testing is mandatory for correct diagnosis of RMVT. In our institution, 85-90% of RMVT patients demonstrated runs of ventricular tachycardia or sustained ventricular tachycardia while on a treadmill (exercise test) or during isoproterenol infusion. RMVT was inducible by programmed electrical right ventricular stimulation in only 13% of our patients. Therefore, in patients with suspected RMVT programmed electrophysiological stimulation is only useful to differentiate a ventricular tachycardia from a supraventricular tachycardia with bundle brunch block or in patients with unexplained syncope. The prognosis is considered generally good; in our patients no life threatening ventricular tachyarrhythmias were observed during a follow-up of up to 4 years. Verapamil and beta-adrenoceptor antagonists generally offer symptomatic improvement. In some cases treatment with a class III antiarrhythmic agent is necessary. While drug-refractory paroxysmal sustained idiopathic ventricular tachycardia can be abladed with both immediate and long-term success, catheter
Philips, Binu; te Riele, Anneline S J M; Sawant, Abhishek; Kareddy, Vishnupriya; James, Cynthia A; Murray, Brittney; Tichnell, Crystal; Kassamali, Bina; Nazarian, Saman; Judge, Daniel P; Calkins, Hugh; Tandri, Harikrishna
Variable success rates have been reported after epicardial radiofrequency catheter ablation (RFA) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The details of the electroanatomic substrate are limited to a few studies, and the characteristics of the recurrent ventricular tachycardia (VT) in ARVD/C remain largely unknown. The purpose of this study was to report procedural strategy, safety, and efficacy of epicardial RFA at a tertiary single center with a focus on the characteristics of the substrate and recurrent VT. We included 30 ARVD/C patients (mean age 33.1 ± 11.1 years, 53% male) who underwent endocardial/epicardial mapping and epicardial catheter ablation of VT at the Johns Hopkins Hospital. Implantable cardioverter-defibrillator interrogations were evaluated for VT recurrence. The majority of critical VT circuits (69%) were on the epicardial surface, mostly in the subtricuspid region. Eight patients (27%) experienced VT recurrence after epicardial RFA, and the VT-free survival was 83%, 76%, and 70% at 6,12, and 24, months respectively. A significant reduction of VT burden was observed (P <.001), even among those with VT recurrence. No complications occurred except for acute pericarditis in 1 patient. The majority of VT recurrences occurred during the first year after RFA, during exercise, had fast cycle lengths, and required implantable cardioverter-defibrillator shock for termination. The vast majority of critical VT circuits were epicardial, mostly in the subtricuspid region. Epicardial RFA of VT appears to be both safe and effective in achieving arrhythmia control in ARVD/C. The features of the recurrent VT suggest a possible catecholamine-mediated mechanism with an origin in a region not targeted for ablation. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Badui, E; Cruz, H; Almazan, A; Enciso, R; Soberanis, N; Garcia, R
The authors present a case of a thirty-nine-year-old white man in good health who developed episodes of ventricular tachycardia as a first manifestation of a right ventricular myxoma, which was diagnosed by two-dimensional echocardiogram and then resected with no complications and total disappearance of the cardiac arrhythmia. After reviewing the literature they consider the present case as a rare manifestation of an infrequent location of an uncommon disease.
Behere, Shashank P; Weindling, Steven N
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly malignant inheritable cardiac channelopathy. The past decade and a half has provided exciting new discoveries elucidating the genetic etiology and pathophysiology of CPVT. This review of the current literature on CPVT aims to summarize the state of the art in our understanding of the genetic etiology and the molecular pathogenesis of CPVT, and how these relate to our current approach to diagnosis and management. We will also shed light on groundbreaking new work that will continue to refine the management of CPVT in the future. As our knowledge of CPVT continues to grow, further studies will yield a better understanding of the efficacy and pitfalls of established diagnostic approaches and therapies as well as help shape newer diagnostic and treatment strategies. Two separate searches were run on the National Center for Biotechnology Information's (NCBI) website. The first used the medical subject headings (MeSH) database using the term “catecholaminergic polymorphic ventricular tachycardia” that was run on the PubMed database using the age filter (birth to 18 years), and it yielded 58 results. The second search using the MeSH database with the search term “catecholaminergic polymorphic ventricular tachycardia,” applying no filters yielded 178 results. The abstracts of all these articles were studied and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles were further explored and read in full. PMID:27212848
Liu, Nian; Denegri, Marco; Dun, Wen; Boncompagni, Simona; Lodola, Francesco; Protasi, Feliciano; Napolitano, Carlo; Boyden, Penelope A; Priori, Silvia G
The recessive form of catecholaminergic polymorphic ventricular tachycardia is caused by mutations in the cardiac calsequestrin-2 gene; this variant of catecholaminergic polymorphic ventricular tachycardia is less well characterized than the autosomal-dominant form caused by mutations in the ryanodine receptor-2 gene. We characterized the intracellular Ca²⁺ homeostasis, electrophysiological properties, and ultrastructural features of the Ca²⁺ release units in the homozygous calsequestrin 2-R33Q knock-in mouse model (R33Q) R33Q knock-in mouse model. We studied isolated R33Q and wild-type ventricular myocytes and observed properties not previously identified in a catecholaminergic polymorphic ventricular tachycardia model. As compared with wild-type cells, R33Q myocytes (1) show spontaneous Ca²⁺ waves unable to propagate as cell-wide waves; (2) show smaller Ca²⁺sparks with shortened coupling intervals, suggesting a reduced refractoriness of Ca²⁺ release events; (3) have a reduction of the area of membrane contact, of the junctions between junctional sarcoplasmic reticulum and T tubules (couplons), and of junctional sarcoplasmic reticulum volume; (4) have a propensity to develop phase 2 to 4 afterdepolarizations that can elicit triggered beats; and (5) involve viral gene transfer with wild-type cardiac calsequestrin-2 that is able to normalize structural abnormalities and to restore cell-wide calcium wave propagation. Our data show that homozygous cardiac calsequestrin-2-R33Q myocytes develop spontaneous Ca²⁺ release events with a broad range of intervals coupled to preceding beats, leading to the formation of early and delayed afterdepolarizations. They also display a major disruption of the Ca²⁺ release unit architecture that leads to fragmentation of spontaneous Ca²⁺ waves. We propose that these 2 substrates in R33Q myocytes synergize to provide a new arrhythmogenic mechanism for catecholaminergic polymorphic ventricular tachycardia.
MacIntyre, Ciorsti J; Sapp, John L
Implantable cardioverter defibrillators (ICDs) reduce the mortality risk associated with recurrent ventricular tachycardia (VT) and can frequently terminate VT episodes painlessly, but do not prevent recurrent episodes. For patients with symptomatic recurrences, frequent asymptomatic recurrences, ICD shocks, or VT storm, most clinicians recommend strategies to suppress VT. The proarrhythmic mortality risk of antiarrhythmic drugs (AADs) may be mitigated by the presence of an ICD, but these medications are limited by high recurrence rates, and unfavorable side effect profiles. Catheter ablation is an alternative or adjunctive option, but is also limited by incomplete efficacy and procedural risk. Copyright © 2017 Elsevier Inc. All rights reserved.
Thompson, Nathaniel; Frontera, Antonio; Takigawa, Masateru; Cheniti, Ghassen; Massoullie, Gregoire; Cochet, Hubert; Denis, Arnaud; Chaumeil, Arnaud; Derval, Nicolas; Hocini, Meleze; Haissaguerre, Michel; Jais, Pierre; Sacher, Frederic
Although catheter ablation has been successful in reducing the recurrence of ventricular tachycardia in patients with ischemic disease, outcomes in patients with nonischemic cardiomyopathy (NICM) have not met with the same results. Success is predicated on a methodical approach to diagnosis of disease type and identification of critical substrate, and the ablation strategies used. Cardiac MRI with delayed enhancement is able to identify areas of substrate involvement, particularly in situations when conventional catheter mapping is not able to do so. Radiofrequency needle, irrigated bipolar radiofrequency, and transcoronary alcohol ablation are effective and alternative techniques to endocardial and epicardial ablation. Copyright © 2016 Elsevier Inc. All rights reserved.
Gianni, Carola; Mohanty, Sanghamitra; Trivedi, Chintan; Di Biase, Luigi; Al-Ahmad, Amin; Natale, Andrea; David Burkhardt, J
Ventricular tachycardia (VT) ablation is usually performed with an ablation catheter that delivers unipolar radiofrequency (RF) energy to eliminate the re-entry circuit responsible for VT. However, there are some instances when unipolar RF ablation fails, notably in VTs with a deep intramural origin, or cases in which epicardial access is not attainable due to prior cardiac surgery. To overcome these limitations, several alternative approaches have been used in clinical practice, including alcohol ablation or coil embolization, simultaneous unipolar or bipolar RF ablation, surgical ablation, or noninvasive ablation with stereotactic radiosurgery. This review article describes some of these alternative techniques. Copyright © 2016 Elsevier Inc. All rights reserved.
Mehrhof, Felix; Stockburger, Martin; Schuette, Hartwig; Haverkamp, Wilhelm; Dietz, Rainer
The case of a 32-year-old man with sustained ventricular tachycardia and hypotension is described. Following pharmacological treatment the patient switched to a sinus rhythm and was transferred to a university hospital for further diagnostic procedures and treatment. Cardiac catherisation ruled out underlying coronary artery disease, and cardiac MRI as well as echocardiography demonstrated a moderately reduced left ventricular ejection fraction, marked thickening of the interventricular septum and extensive intramural and epicardial infiltration of both ventricles. Endomyocardial biopsies were inconclusive; an implantable cardioverter defibrillator (ICD) was implanted in order to prevent a fatal arrhythmic event. Only repeated lymph node biopsies revealed typical findings of granulomatous disease, which together with the clinical course and the cardiac MRI findings strongly supported cardiac sarcoidosis. A few days after initiation of therapy with corticosteroids, the patient experienced the first of a number of ICD discharges, demanding aggressive anti-arrhythmic treatment regimen for the future. PMID:21686620
Ventricular Tachycardia and Early Fibrillation in Patients With Brugada Syndrome and Ischemic Cardiomyopathy Show Predictable Frequency-Phase Properties on the Precordial ECG Consistent With the Respective Arrhythmogenic Substrate
Calvo, David; Atienza, Felipe; Saiz, Javier; Martínez, Laura; Ávila, Pablo; Rubín, José; Herreros, Benito; Arenal, Ángel; García-Fernández, Javier; Ferrer, Ana; Sebastián, Rafael; Martínez-Camblor, Pablo; Jalife, José
Background— Ventricular fibrillation (VF) has been proposed to be maintained by localized high-frequency sources. We tested whether spectral-phase analysis of the precordial ECG enabled identification of periodic activation patterns generated by such sources. Methods and Results— Precordial ECGs were recorded from 15 ischemic cardiomyopathy and 15 Brugada syndrome (type 1 ECG) patients during induced VF and analyzed in the frequency-phase domain. Despite temporal variability, induced VF episodes lasting 19.6±7.9 s displayed distinctly high power at a common frequency (shared frequency, 5.7±1.1 Hz) in all leads about half of the time. In patients with Brugada syndrome, phase analysis of shared frequency showed a V1–V6 sequence as would be expected from patients displaying a type 1 ECG pattern (P<0.001). Hilbert-based phases confirmed that the most stable sequence over the whole VF duration was V1–V6. Analysis of shared frequency in ischemic cardiomyopathy patients with anteroseptal (n=4), apical (n=3), and inferolateral (n=4) myocardial infarction displayed a sequence starting at V1–V2, V3–V4, and V5–V6, respectively, consistent with an activation origin at the scar location (P=0.005). Sequences correlated with the Hilbert-based phase analysis (P<0.001). Posterior infarction (n=4) displayed no specific sequence. On paired comparison, phase sequences during monomorphic ventricular tachycardia correlated moderately with VF (P<0.001). Moreover, there was a dominant frequency gradient from precordial leads facing the scar region to the contralateral leads (5.8±0.8 versus 5.4±1.1 Hz; P=0.004). Conclusions— Noninvasive analysis of ventricular tachycardia and early VF in patients with Brugada syndrome and ischemic cardiomyopathy shows a predictable sequence in the frequency-phase domain, consistent with anatomic location of the arrhythmogenic substrate. PMID:26253505
Bhavnani, Sanjeev P; Clyne, Christopher A
Bidirectional ventricular tachycardia (BVT) is an uncommon type of polymorphic ventricular tachycardia (PVT) with alternating polarity of the QRS complex most commonly described digitalis toxicity. Recent data has demonstrated the possible molecular basis of this electrocardiographic phenomenon. To our knowledge this is the first reported case of BVT in a patient with orthotopic cardiac transplantation and coronary allograft vasculopathy.
Nyegaard, Mette; Overgaard, Michael T.; Søndergaard, Mads T.; Vranas, Marta; Behr, Elijah R.; Hildebrandt, Lasse L.; Lund, Jacob; Hedley, Paula L.; Camm, A. John; Wettrell, Göran; Fosdal, Inger; Christiansen, Michael; Børglum, Anders D.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe dominantly inherited form of CPVT-like arrhythmias, we mapped the disease locus to chromosome 14q31-32. Sequencing CALM1 encoding calmodulin revealed a heterozygous missense mutation (c.161A>T [p.Asn53Ile]) segregating with the disease. A second, de novo, missense mutation (c.293A>G [p.Asn97Ser]) was subsequently identified in an individual of Iraqi origin; this individual was diagnosed with CPVT from a screening of 61 arrhythmia samples with no identified RYR2 mutations. Both CALM1 substitutions demonstrated compromised calcium binding, and p.Asn97Ser displayed an aberrant interaction with the RYR2 calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac death. PMID:23040497
Killu, Ammar M; Mulpuru, Siva K; Asirvatham, Samuel J
Ventricular tachycardia (VT) may occur in the presence or absence of structural heart disease. Given that the management of VT hinges on the presence of symptoms and risk of sudden cardiac death (SCD), the main treatment goals are elimination of symptoms (including frequent implantable cardioverter defibrillator [ICD] therapies) and prevention of SCD. Unfortunately, medical management is suboptimal in a significant proportion of patients. As such, ablative therapy plays a prominent role in the treatment of ventricular tachycardia. In this review, we will discuss various VT disorders that are encountered in patients with and without structural heart disease. Further, we will highlight salient features regarding mapping and ablation of the various VT syndromes. Finally, we will discuss what lies on the horizon for VT ablation. Expert commentary: Meticulous mapping should aim to find the region that is most likely to be successful and least likely to result in a complication. Although recognition of the various mechanisms of VT, familiarity with different methods to mapping and ablation, and awareness of potential limitations of current approaches is critical, a thorough understanding of the fundamental principles and nuances of each facet within EP is required to ensure optimal outcomes for our patients.
Jadhav, Amar P; Nusair, Maein B; Ingole, Apekshe; Alpert, Martin A
Inhalation or ingestion of aluminum phosphide (AP) generates phosphine gas on exposure to moisture, which, in turn, produces widespread organ toxicity primarily involving the lungs, heart, liver, and kidneys. Cardiac manifestations of AP poisoning include toxic myocarditis, refractory heart failure, bradyarrhythmias, and tachyarrhythmias including ventricular tachycardia (VT). A 19-year-old depressed male farm worker ingested ten 500-mg tablets of Celphos in a suicide attempt. Each Celphos tablet contains 56% AP. Over the course of 10 hours, the patient developed heart failure and respiratory failure associated with a rise in serum troponin level to 12.7 ng/mL. Serum electrolytes (including magnesium) and serum creatinine levels were normal throughout. His course was further complicated by acidemia and hypotension. These hemodynamic and metabolic abnormalities were initially corrected by assisted ventilation and continuous veno-venous hemofiltration. However, he developed hemodynamically stable sustained monomorphic VT, which proved unresponsive to treatment with intravenous magnesium sulfate and intravenous amiodarone therapy. After a decline in blood pressure, 6 attempts at electrocardioversion failed to restore sinus rhythm, and he died. Postmortem histologic examination of myocardium showed contraction band necrosis, early coagulation necrosis, edema, hemorrhage, and pyknosis of cardiac myocyte nuclei. Ventricular tachycardia associated with AP poisoning has been successfully treated with magnesium sulfate, amiodarone, and electrocardioversion. This case report documents failure of all 3 of these therapeutic modalities.
Wu, Lin; Tian, Hong; Wang, Feng; Liang, Xuecun; Chen, Gang
Most idiopathic right ventricular tachycardias originate from the outflow tract. We present a case series of idiopathic incessant ventricular tachycardia arising from unusual sites of the right ventricle in children, which were well resolved by catheter ablation. A retrospective review was performed of all three patients who underwent ablation of idiopathic ventricular tachycardia below the level of the right ventricular outflow tract using three-dimensional mapping in our institute. Result All three patients presented with tachycardia-induced cardiomyopathy due to incessant ventricular tachycardia on first admission. The sites of successful ablation were at the proximal right bundle branch, distal right bundle branch, and apex of the right ventricle, respectively. No complications occurred, and there has been no recurrence of ventricular tachycardia after the final ablation at an average follow-up period of 9 months. All three patients have achieved normalisation of left ventricular size and systolic function. Incessant idiopathic ventricular tachycardia originating from unusual sites of the right ventricle in children, resulting in significant symptoms and impaired ventricular function, can be successfully treated with catheter ablation.
McClelland, J H; Daubert, J P; Kavanagh, K M; Harrell, F E; Ideker, R E
Cardioversion shocks given during ventricular tachycardia may cause ventricular fibrillation or acceleration of ventricular tachycardia, or arrest the tachycardia. A recently proposed theory may explain why the former two phenomena may occur. Briefly, this theory states that potential gradient shock fields of a critical strength delivered to tissue with a critical degree of refractoriness will cause circulating wave fronts of ventricular activation ("rotors") manifest as ventricular arrhythmia. We tested this theory by delivering nonsynchronized shocks 50% higher than defibrillation threshold or 50% lower than defibrillation threshold during 275 episodes of ventricular tachycardia in eight dogs with 5- to 7-day-old myocardial infarcts. Shocks stronger than the defibrillation threshold are likely to create shock fields in the ventricles everywhere stronger than this critical value, and therefore would not generate rotors. Shocks less strong than the defibrillation threshold may create shock fields within the ventricles that include the critical value, and therefore cause rotors if given when critically refractory tissue is present. Nonsynchronized shocks were used to increase the likelihood of encountering tissue with a critical degree of refractoriness. Ventricular fibrillation or acceleration of ventricular tachycardia occurred following 83 of 138 (60%) low strength shocks and following 20 of 137 (14.6%) high strength shocks. The pooled odds ratio for induction of ventricular fibrillation or accelerated ventricular tachycardia after low strength shocks as compared to high strength shocks was 8.9. when given during ventricular tachycardia, low strength shocks are much more likely to cause ventricular fibrillation or accelerated ventricular tachycardia than are high strength shocks (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Ozturk, Cengiz; Cakmak, Tolga; Aparci, Mustafa; Metin, Suleyman; Yildirim, Ali Osman
Premature ventricular contractions (PVCs) presenting as isolated complexes are insignificant, but if they present as salvos they are considered indicators of high risk for potentially fatal arrhythmias. We present the case of a 39-yr-old male military parachuter with PVCs and ventricular tachycardia that were incidentally detected on ECG and treated with radiofrequency catheter ablation (RFCA). He had no significant past medical history. Physical examination and biochemical tests were normal. Transthoracic echocardiography showed no structural heart disease. Due to frequent ventricular extrasystoles (VES) detected on his ECG, 24-h Holter monitoring was conducted and revealed VES, including 13,351 isolated PVCs, 1427 episodes of bigeminy, 397 of trigeminy, 30 couplets, and 4 salvo periods. After beta-blocker and calcium channel blocker treatment for 1 mo, his repeat 24-h Holter monitoring showed 18,414 isolated PVCs, 819 episodes of bigeminy, 181 of trigeminy, and 6 couplet VES, but no episodes of salvos. Electrophysiological studies (EPS) were performed and the baseline measurements were: basic cycle length: 890 ms; atrium His interval: 78 ms; and ventricular His interval: 54 ms. VES were found to orginate from the right ventricular outflow tract and were terminated by RFCA. Medical treatment was stopped. Repeat Holter showed no VES. The parachuter was qualified for full duties. As the patient is an aircrew member and further usage of antiarrhythmic agents will interfere with his flying status, instead of initiating a drug therapy again, we performed EPS and RFCA as an effective and dependable method in order to treat and to determine his fitness.
Kassotis, John; Slesinger, Todd; Festic, Emir; Voigt, Louis; Reddy, C V R
Most wide-complex tachycardias encountered in the emergency department (ED) are ventricular in origin, most commonly associated with structural heart disease. Ventricular tachyarrhythmias range in severity from life-threatening rhythms (eg, ventricular fibrillation and hemodynamically compromising ventricular tachycardia [VT]) to idiopathic forms of VT, which have a benign clinical course and a more favorable prognosis. The authors present the case of a 34-year-old woman who presented to the ED, with a wide-complex tachycardia with a right-bundle-branch block (RBBB) morphology and a right inferior axis, which was terminated with adenosine. The patient was previously misdiagnosed as suffering from a paroxysmal supraventricular tachycardia (SVT), which was unresponsive to beta-blocker therapy. Although the tachycardia responded to adenosine, suggestive of an SVT, the patient was referred to the arrhythmia service, where further work-up revealed an uncommon form of an idiopathic VT, originating from the left anterior fascicle. The authors discuss the unique electrocardiographic and electrophysiologic properties and useful diagnostic maneuvers required to properly identify this form of VT.
Cordero Cabra, J A; Iturralde Torres, P; Lara Vaca, S; Colín Lizalde, L; Kershenovich, S; Carvajal, A; González Hermosillo, J A
We performed radiofrequency catheter ablation in 14 consecutive patients with Ventricular Tachycardia (VT) 10 of which had healthy hearts, one patient with ischemic heart disease, one with arrhythmogenic dysplasia, one with dilated cardiomyopathy, and one with congenital heart disease. The localization of the VT was: 10 in the left posterior fascicular region, 3 in the right ventricular outflow tract (RVOT), and one patient with ischemic heart disease with the substrate in the left ventricular apex. All of them with VT refractory to pharmacological management, using an average of 2.7 drugs per patient. After all patients underwent Electrophysiological Study (EPS), an intracavitary mapping was performed, in order to locate the arrhythmogenic substrate. Later on, the RF ablation was performed, delivering an average of 15 pulses, using 40 Watts, and an average time of 25 sec. per pulse. The procedure was successful in 60% of the fascicular VT, with a 16% of recurrence; 100% of success with those originated in the RVOT with no recurrence; in the ischemic patient we achieved primary success, but with recurrence, a second session was successful with no recurrence up to date. No major complications occurred in this group. Those patients which showed no success required the use of antiarrhythmic drugs. The total success of the series is 71.4% with 10% recurrence, and no mortality.
Lujan, Heidi L.; DiCarlo, Stephen E.
Abstract Reperfusion‐induced lethal ventricular arrhythmias are observed during relief of coronary artery spasm, with unstable angina, exercise‐induced ischemia, and silent ischemia. Accordingly, significant efforts are underway to understand the mechanisms responsible for reperfusion‐induced lethal arrhythmias and mice have become increasingly important in these efforts. However, although reperfusion‐induced sustained ventricular tachycardia leading to ventricular fibrillation (VF) has been recorded in many models, reports in mice are sparse and of limited success. Importantly, none of these studies were conducted in intact, conscious mice. Accordingly, a chronically instrumented, intact, conscious murine model of reperfusion‐induced lethal arrhythmias has the potential to be of major importance for advancing the concepts and methods that drive cardiovascular therapies. Therefore, we describe, for the first time, the use of an intact, conscious, murine model of reperfusion‐induced lethal arrhythmias. Male mice (n = 9) were instrumented to record cardiac output and the electrocardiogram. In addition, a snare was placed around the left main coronary artery. Following recovery, the susceptibility to sustained ventricular tachycardia produced by 3 min of occlusion and reperfusion of the left main coronary artery was determined in conscious mice by pulling on the snare. Reperfusion culminated in sustained ventricular tachycardia, leading to VF, in all nine conscious mice. The procedures conducted in conscious C57BL/6J mice, a strain commonly used in transgenic studies, can be utilized in genetically modified models to enhance our understanding of single gene defects on reperfusion‐induced lethal ventricular arrhythmias in intact, conscious, and complex animals. PMID:24973331
Chen, Jian; Hoff, Per Ivar; Rossvoll, Ole; De Bortoli, Alessandro; Solheim, Eivind; Sun, Lizhi; Schuster, Peter; Larsen, Terje; Ohm, Ole-Jørgen
Ventricular arrhythmias arising from the fibrous rings have been demonstrated, but knowledge about the aortomitral continuity (AMC) as a source of the arrhytmias is still limited. The objective is to describe the characteristics of ventricular arrhythmias originating from the AMC in patients without structural heart disease. Ten patients with ventricular tachycardia (VT) and/or premature ventricular contractions, who had been successfully treated by catheter ablation at the AMC beneath the aortic valve, were enrolled. Clinical data and electrocardiographic characteristics were analysed. Three of the 10 patients had previously registered episodes of supraventricular tachycardia and had undergone catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). In four patients with anterior AMC location, early R/S wave transition was found in the precordial leads, with equal R and S amplitudes in V2, rS in V1, and R in V3. In six patients whose VT arose from the middle part of the AMC, we demonstrated a special ('rebound') transition pattern, with which equal R and S amplitudes occurred in V2, and high R waves in V1 and V3. In the anterior AMC location, the S/R ratios in leads V1 and V2 were >1 and statistically significantly higher than those located in the middle (V1: 1.59 vs. 0.23, P< 0.001; V2: 1.52 vs. 0.41, P< 0.01). We report a series of ventricular arrhythmias arising from the AMC with different R/S wave transition patterns in the precordial leads on the electrocardiogram. There may be a relationship between ventricular arrhythmias from AMC and AVNRT.
Nishiuchi, Suguru; Nogami, Akihiko; Naito, Shigeto
A 36-year-old male presented with verapamil-sensitive narrow QRS tachycardia. The patient underwent the catheter ablation of common idiopathic left fascicular ventricular tachycardia (ILVT) 2 years ago. During narrow QRS tachycardia, the diastolic and presystolic potentials (P1 and P2) were recorded at the left septum. Activation sequences of P1 and P2 were opposite from those in common ILVT. Entrainment of P1 at the upper septum exhibited concealed fusion and S-QRS equal to P1-QRS. Radiofrequency current to P1 suppressed VT. Idiopathic left upper septal VT might be the antidromic macroreentry of the common form of ILVT.
Kopecky, Kathleen; Afzal, Aasim; Felius, Joost; Hall, Shelley A; Mendez, Jose C; Assar, Manish; Mason, David P; Bindra, Amarinder S
Ventricular tachycardia (VT) commonly occurs in patients with ischemic or non-ischemic cardiomyopathy and requires anti-arrhythmic drugs, ablation or advanced circulatory support. However, life-threatening VT may be refractory to these therapies, and may cause frequent implantable cardioverter defibrillator (ICD) discharges. Left cardiac sympathetic denervation reduces the occurrence of these fatal arrhythmias by inhibiting the sympathetic outflow to the cardiac tissue. We present a 69-year-old man with non-ischemic cardiomyopathy, life-threatening VT, and hemodynamic instability with numerous ICD discharges who remained refractory to antiarrhythmic drug therapy and ablation attempts. He was effectively treated with bilateral cardiac sympathectomy. Six months later, he remained free of VT with no ICD discharges. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Grothoff, Matthias; Dinov, Borislav; Kosiuk, Jedrzej; Richter, Sergio; Sommer, Philipp; Breithardt, Ole A.; Bollmann, Andreas; Arya, Arash; Hindricks, Gerhard
Radiofrequency (RF) ablation with irrigated tip catheters decreases the likelihood of thrombus and char formation and enables the creation of larger lesions. Due to the potential dramatic consequences, the prevention of thromboembolic events is of particular importance for left-sided procedures. Although acute success rates of ventricular tachycardia (VT) ablation are satisfactory, recurrence rate is high. Apart from the progress of the underlying disease, reconduction and the lack of effective transmural lesions play a major role for VT recurrences. This paper reviews principles of lesion formation with radiofrequency and the effect of tip irrigation as well as recent advances in new technology. Potential areas of further development of catheter technology might be the improvement of mapping by better substrate definition and resolution, the introduction of bipolar and multipolar ablation techniques into clinical routine, and the use of alternative sources of energy. PMID:25705659
Scolari, Diogo; Fagundes, Rubem D R; Russomano, Thaís; Zwetsch, Iuberi Carson
This paper deals with automatic recognition of cardiac arrhythmias that require immediate electrical defibrillation therapy (ventricular fibrillation and ventricular tachycardia), through ECG (electrocardiogram) samples. The DD-HMM (discrete density hidden Markov model) and RBF (radial basis function) neural network algorithms were compared in the following aspects: precision, defined as correct recognition percentage and process time, defined as the delay since the ECG input until the result, indicating shock or non-shock events. The results show that RBF is more precise than DD-HMM but not so fast to evaluate. PhysioNet database files were used to train and to validate the algorithms.
Dan Do, Van Buu; Chang, Shih-Lin; Lin, Yenn-Jiang; Chen, Shih-Ann
A 44-year-old man with structurally normal heart underwent catheter ablation of left ventricular summit tachycardia. The initial mapping revealed the origin of tachycardia at the junction of great cardiac vein and anterior interventricular vein. During ablation the exit site shifted to the nearby regions, which was recognized by subtle changes of 12-lead ECG. Mapping and ablating at different exit sites rendered the tachycardia noninducible.
Salerno, D M; Katz, A; Dunbar, D N; Fjeldos-Sperbeck, K
We have observed hypokalemia after cardioversion from spontaneous out-of-hospital ventricular fibrillation and induced ventricular tachycardia. To test the hypothesis that the hormone response to the hemodynamic stress of the arrhythmia initiated the change in potassium, we compared the electrolytes and hormones in three groups of patients. We observed a decrease in serum potassium and magnesium after cardioversion from ventricular tachycardia induced by programmed stimulation, but not after normal programmed stimulation of the ventricle or after cardioversion from stable atrial fibrillation. These changes were preceded first by a rise in norepinephrine and epinephrine, then a rise in glucose, followed by a rise in insulin. The stimulus for these changes was probably the hypotension associated with ventricular tachycardia. The sequence of changes suggests that the decrease of potassium and magnesium after ventricular tachycardia was due to a shift of the electrolytes into cells, related to the insulin-mediated movement of glucose from the blood into cells.
Emori, T; Ohe, T; Shimomura, K
A 41 year old woman had multiform ventricular tachycardia without QT prolongation. Monophasic action potentials were recorded from the right ventricle during the attacks of multiform ventricular tachycardia and effective refractory periods were examined at the same sites. There was no abnormal hump to suggest early afterdepolarisation in the monophasic action potentials, but there was dispersion of the effective refractory period in the right ventricle (80 ms). Stimulation from the right ventricular apex, where the effective refractory period was shortest, reproducibly induced multiform ventricular tachycardia. Two weeks after admission, when her condition was stable, multiform ventricular tachycardia could not be induced and the dispersion of the effective refractory period in the right ventricle was 20 ms. PMID:8489870
Berruezo, Antonio; Mont, Lluis; Nava, Santiago; Chueca, Enrique; Bartholomay, Eduardo; Brugada, Josep
Some ventricular tachycardias (VTs) originating from the epicardium are not suitable for endocardial radiofrequency ablation and require an epicardial approach. The aim of this study was to define the ECG characteristics that may identify an epicardial origin of VTs. We analyzed the 12-lead ECG recordings during epicardial and endocardial left ventricular pacing in 9 patients to verify the hypothesis that the epicardial origin of the ventricular activation widens the initial part of the QRS complex. Then, we analyzed the ECG pattern in 14 VTs successfully ablated from the epicardium after a failed endocardial approach (group A), in 27 VTs successfully ablated from the endocardium (group B), and in 28 additional VTs that could not be ablated from the endocardium (group C). Four distinct intervals of ventricular activation were defined and measured: (1) the pseudodelta wave, (2) the intrinsicoid deflection time in V2, (3) the shortest RS complex, and (4) the QRS complex. VTs from groups A and C showed a significantly longer pseudodelta wave, intrinsicoid deflection time, and RS complex duration compared with VTs of group B. There was no difference between groups A and C. A pseudodelta wave of > or =34 ms has a sensitivity of 83% and a specificity of 95%, an intrinsicoid deflection time of > or =85 ms has a sensitivity of 87% and a specificity of 90%, and an RS complex duration of > or =121 ms has a sensitivity of 76% and a specificity of 85% in identifying an epicardial origin of the VTs. ECG suggests VTs originating from the epicardium and those with an unsuccessful radiofrequency ablation from the endocardium.
Feld, H; Guadanino, V; Hollander, G; Greengart, A; Lichstein, E; Shani, J
Sustained ventricular tachycardia induced by exercise is uncommon. This is a report of a patient who has a positive exercise test at a high level of exercise. The electrocardiogram has classic ischemic ST depressions. Following the appearance of these ST depressions, the patient developed ventricular tachycardia at a rapid rate. Workup that included an echocardiogram and cardiac catheterization revealed myocardial bridging of the left anterior descending artery as the only structural abnormality. Electrophysiologic studies revealed the patient to have ventricular tachycardia only with isoproterenol (Isuprel) infusion.
Sacher, Frederic; Lim, Han S; Derval, Nicolas; Denis, Arnaud; Berte, Benjamin; Yamashita, Seigo; Hocini, Mélèze; Haissaguerre, Michel; Jaïs, Pierre
Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks. However, the optimal endpoint for VT ablation has been debated and additional endpoints have been proposed. At the same time, ablation strategies aiming at homogenizing the substrate of scar-related VT have been reported. Our method to homogenize the substrate consists of local abnormal ventricular activity (LAVA) elimination. LAVA are high-frequency sharp signals that represent near-field signals of slowly conducting tissue and hence potential VT isthmuses. Pacing maneuvers are sometimes required to differentiate them from far-field signals. Delayed enhancement on cardiac MRI and/or wall thinning on multidetector computed tomography are also extremely helpful to identify the areas of interest during ablation. A strategy aiming at careful LAVA mapping, ablation, and elimination is feasible and can be achieved in about 70% of patients with scar-related VT. Complete LAVA elimination is associated with a better outcome when compared to LAVA persistence even when VT is rendered noninducible. This is a simple approach, with a clear endpoint and the ability to ablate in sinus rhythm. This strategy significantly benefits from high-definition imaging, mapping, and epicardial access. © 2014 Wiley Periodicals, Inc.
Wase, Abdul; Masood, Abdul-Mannan; Garikipati, Naga V; Mufti, Omar; Kabir, Anwarul
Bidirectional ventricular tachycardia (BVT) is a rare variety of tachycardia with morphologically distinct presentation: The QRS axis and/or morphology is alternating in the frontal plane leads. Since its original description in association with digitalis,(1) numerous cases of this fascinating tachycardia with disparate etiologies and mechanisms have been postulated. We report a patient with BVT in association with non-ST elevation myocardial infarction and severe cardiomyopathy in the absence of digoxin toxicity.
Sacher, Frederic; Reichlin, Tobias; Zado, Erica S; Field, Michael E; Viles-Gonzalez, Juan F; Peichl, Petr; Ellenbogen, Kenneth A; Maury, Philippe; Dukkipati, Srinivas R; Picard, Francois; Kautzner, Josef; Barandon, Laurent; Koneru, Jayanthi N; Ritter, Philippe; Mahida, Saagar; Calderon, Joachim; Derval, Nicolas; Denis, Arnaud; Cochet, Hubert; Shepard, Richard K; Corre, Jerome; Coffey, James O; Garcia, Fermin; Hocini, Meleze; Tedrow, Usha; Haissaguerre, Michel; d'Avila, Andre; Stevenson, William G; Marchlinski, Francis E; Jais, Pierre
Left ventricular assist devices (LVADs) are increasingly used as a bridge to cardiac transplantation or as destination therapy. Patients with LVADs are at high risk for ventricular arrhythmias. This study describes ventricular arrhythmia characteristics and ablation in patients implanted with a Heart Mate II device. All patients with a Heart Mate II device who underwent ventricular arrhythmia catheter ablation at 9 tertiary centers were included. Thirty-four patients (30 male, age 58±10 years) underwent 39 ablation procedures. The underlying cardiomyopathy pathogenesis was ischemic in 21 and nonischemic in 13 patients with a mean left ventricular ejection fraction of 17%±5% before LVAD implantation. One hundred and ten ventricular tachycardias (VTs; cycle lengths, 230-740 ms, arrhythmic storm n=28) and 2 ventricular fibrillation triggers were targeted (25 transseptal, 14 retrograde aortic approaches). Nine patients required VT ablation <1 month after LVAD implantation because of intractable VT. Only 10/110 (9%) of the targeted VTs were related to the Heart Mate II cannula. During follow-up, 7 patients were transplanted and 10 died. Of the remaining 17 patients, 13 were arrhythmia-free at 25±15 months. In 1 patient with VT recurrence, change of turbine speed from 9400 to 9000 rpm extinguished VT. Catheter ablation of VT among LVAD recipients is feasible and reasonably safe even soon after LVAD implantation. Intrinsic myocardial scar, rather than the apical cannula, seems to be the dominant substrate. © 2015 American Heart Association, Inc.
Choi, Eue-Keun; Kumar, Saurabh; Nagashima, Koichi; Lin, Kaity Y; Barbhaiya, Chirag R; Chinitz, Jason S; Enriquez, Alan D; Helmbold, Alan F; Baldinger, Samuel H; Tedrow, Usha B; Koplan, Bruce A; Michaud, Gregory F; John, Roy M; Epstein, Laurence M; Stevenson, William G
In patients presenting with spontaneous sustained ventricular tachycardia (VT) from the outflow-tract region without overt structural heart disease ablation may target premature ventricular contractions (PVCs) when VT is not inducible. We aimed to determine whether inducibility of VT affects ablation outcome. Data from 54 patients (31 men; age, 52 ± 13 years) without overt structural heart disease who underwent catheter ablation for symptomatic sustained VT originating from the right- or left-ventricular outflow region, including the great vessels. A single morphology of sustained VT was inducible in 18 (33%, SM group) patients, and 11 (20%) had multiple VT morphologies (MM group). VT was not inducible in 25 (46%) patients (VTni group). After ablation, VT was inducible in none of the SM group and in two (17%) patients in the MM group. In the VTni group, ablation targeted PVCs and 12 (48%) patients had some remaining PVCs after ablation. During follow-up (21 ± 19 months), VT recurred in 46% of VTni group, 40% of MM inducible group, and 6% of the SM inducible group (P = 0.004). Analysis of PVC morphology in the VTi group further supported the limitations of targeting PVCs in this population. Absence of inducible VT and multiple VT morphologies are not uncommon in patients with documented sustained outflow-tract VT without overt structural heart disease. Inducible VT is associated with better outcomes, suggesting that attempts to induce VT to guide ablation are important in this population. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: email@example.com.
Marai, Ibrahim; Khoury, Asaad; Suleiman, Mahmoud; Gepstein, Lior; Blich, Miri; Lorber, Abraham; Boulos, Monther
In this study, the clinical and implantable cardioverter-defibrillator (ICD)-related follow-up of patients with catecholaminergic polymorphic ventricular tachycardia (CPVT) with homogenous missense mutations in CASQ2 was summarized. Patients were followed in a pediatric cardiology clinic and an ICD clinic. All patients were treated with high-dose β blockers. ICDs were recommended for patients who remained symptomatic despite medical treatment. Twenty-seven patients were followed for 1 to 15 years (median 9). Twenty patients (74%) were symptomatic at diagnosis; 13 (65%) remained symptomatic after treatment with high-dose β blockers and thus were advised to receive ICDs. Eight of these patients refused ICDs, and eventually 6 (75%) died suddenly. Four of the 5 patients who received ICDs had ventricular tachycardia storms treated but not terminated by recurrent ICD shocks. These ventricular tachycardia storms (2 episodes in 2 patients and 1 episode in 2 patient) terminated spontaneously after finishing the programmed ICD shocks, without degeneration to ventricular fibrillation. None of the patients who received ICDs died. In conclusion, patients with CASQ2-associated CPVT should be recommended to receive ICDs to prevent sudden death when medical therapy is not effective. These patients may have recurrent ventricular tachycardia storms treated but not terminated by recurrent ICD shocks, without degeneration to ventricular fibrillation. Copyright © 2012 Elsevier Inc. All rights reserved.
Thornton, Andrew S; Res, Jan; Mekel, Joris M; Jordaens, Luc J
Ablation of idiopathic left ventricular, or fascicular tachycardia can be aided by electroanatomical mapping. The addition of a floppy, magnetically enabled ablation catheter may improve maneuvering as well as decrease mechanically induced arrhythmias and mechanical block. We describe a case of fascicular tachycardia in which both these modalities were used in a sequential fashion. Integration of these modalities should prove even more helpful.
Osaki, Satoru; Alberte, Cesar; Murray, Margaret A; Brahmbhatt, Rinjal D; Johnson, Maryl R; Edwards, Niloo M; Kohmoto, Takushi
Refractory ventricular tachycardia (VT) can be a potentially life-threatening rhythm in the presence of non-ischemic dilated cardiomyopathy, particularly when it results in hemodynamic compromise. A 65-year-old man with non-ischemic cardiomyopathy was referred for multiple episodes of VT. A HeartMate left ventricular assist device (LVAD) was implanted to stabilize and control the VT. However, he had multiple episodes of VT and the frequency of ventricular arrhythmias did not improve after LVAD implantation. He required electrical cardioversion to treat each episode. On Day 41 post-operatively, radiofrequency ablation was performed. Two significant areas of scarring were identified and were successfully ablated. After ablation, he did not have significant sustained VT episodes and was discharged.
Soejima, Kyoko; Nogami, Akihiko; Sekiguchi, Yukio; Harada, Tomoo; Satomi, Kazuhiro; Hirose, Takeshi; Ueda, Akiko; Miwa, Yousuke; Sato, Toshiaki; Nishio, Satoru; Shirai, Yasuhiro; Kowase, Shinya; Murakoshi, Nobuyuki; Kunugi, Shinobu; Murata, Hiroshige; Nitta, Takashi; Aonuma, Kazutaka; Yoshino, Hideaki
In patients with mechanical aortic and mitral valves and left ventricular tachycardia, catheter ablation may be prevented by limited access to the left ventricle. In our series of 6 patients, 2 patients underwent direct surgical ablation and 4 underwent epicardial catheter ablation via a pericardial window. All patients had abnormal low voltage areas with fractionated or delayed isolated potentials on the apical epicardium. Most of the ventricular tachycardias were targeted by pace mapping. Sites with a good pace match or abnormal electrograms were ablated using an irrigated radiofrequency ablation catheter. A microscopic pathological evaluation of the resected tissue from 2 of the open-heart ablation patients revealed dense fibrosis on the epicardium compared with the endocardium, supporting the feasibility of an epicardial ablation for the ventricular tachycardia. Epicardial catheter ablation of ventricular tachycardia is a potentially useful therapy in patients who have mechanical aortic and mitral valves. © 2015 American Heart Association, Inc.
Kim, Sun Moon; Virgadamo, Sebastiano; Gurley, John; Elayi, Claude S
Incessant scar-related reentrant ventricular tachycardia is an important cause of morbidity and mortality. In patients not amenable to emergent radiofrequency catheter ablation, selective transcoronary alcohol ablation has been successfully performed. In our case study, we introduce the novel use of cardioplegia as a mapping technique for identification of the critical ventricular tachycardia isthmus to guide efficient transcoronary alcohol ablation and prevent unnecessary myocardial damage. © 2016 Wiley Periodicals, Inc.
Hutchinson, Lisa J; Stuart, Graham; Walsh, Mark A
The Medtronic LINQ™ was inserted in an 11-month-old boy for close monitoring of rapid ventricular tachycardia. The device is much smaller than the conventional Medtronic loop recorder. The real advantage of the LINQ™ is that it automatically notifies Carelink if any ventricular tachycardia is seen, which is very advantageous for this particular type of patient. This device is ideal for close monitoring of asymptomatic yet potentially dangerous arrhythmias in smaller children.
Maciag, Aleksander; Sterliński, Maciej; Pytkowski, Mariusz; Jankowska, Agnieszka; Szwed, Hanna
Radiofrequency catheter ablation (RFA) in structurally normal heart ventricular arrhythmias has been found to be promising direction of develop. Authors presented the case of successful RFA of symptomatic ventricular tachycardia originating from right ventricle outflow tract (RVOT). Arrhythmogenic locus was localised basing on ECG pattern, analyze of endocardial potentials and pace mapping method. In two-year follow up she was free of symptoms and ventricular arrhythmia, no medication needed. RFA is an effective and safe therapy in ventricular tachycardia in structurally normal heart.
Osaka, M.; Saitoh, H.; Sasabe, N.; Atarashi, H.; Katoh, T.; Hayakawa, H.; Cohen, R. J.
Background: The triggering role of the autonomic nervous system in the initiation of ventricular tachycardia has not been established. To investigate the relationship between changes in autonomic activity and the occurrence of nonsustained ventricular tachycardia (NSVT) we examined heart rate variability (HRV) during the 2-hour period preceding spontaneous episodes of NSVT. Twenty-four subjects were identified retrospectively as having had one episode of NSVT during 24-hour Holter ECC recording. Methods: We measured the mean interval between normal heats (meanRR), the standard deviation of the intervals between beats (SD), the percentage of counts of sequential intervals between normal beats with a change of >50 ms (%RR50), the logarithms of low- and high-frequency spectral components (lnLF, lnHF) of HRV for sequential 10-minute segments preceding NSVT. The correlation dimension (CDim) of HRV was calculated similarly for sequential 20-minute segments. We assessed the significance of the time-course change of each marker over the 120-minute period prior to NSVT onset. Results: MeanRR (P < 0.05), lnLF (P < 0.0001), lnHF (P < 0.0001), the natural logarithm of the ratio of LF to HF (ln[LF/HF]; P < 0.05), and CDim (P < 0.05) showed significant time-course changes during that period, while SD and %RR50 did not. MeanRR, lnLF, lnHF, and CDim all decreased prior to the onset of NSVT, whereas ln(LF/HF) increased. We divided the subjects into two groups: one consisting of 12 patients with coronary artery disease; and the second group of 12 patients without known coronary artery disease. Both groups showed significant changes (P < 0.05) of CDim, lnLF, and lnHF preceding the episodes of NSVT. Conclusions: Changes in the pattern of HRV prior to the onset of episodes of NSVT suggest that changes in autonomic activity may commonly play a role in the triggering of spontaneous episodes of NSVT in susceptible patients. The measured changes suggest a reduction in parasympathetic
Kumar, Saurabh; Barbhaiya, Chirag; Nagashima, Koichi; Choi, Eue-Keun; Epstein, Laurence M; John, Roy M; Maytin, Melanie; Albert, Christine M; Miller, Amy L; Koplan, Bruce A; Michaud, Gregory F; Tedrow, Usha B; Stevenson, William G
Cardiac sarcoid-related ventricular tachycardia (VT) is a rare disorder; the underlying substrate and response to ablation are poorly understood. We sought to examine the ventricular substrate and outcomes of catheter ablation in this population. Of 435 patients with nonischemic cardiomyopathy referred for VT ablation, 21 patients (5%) had cardiac sarcoidosis. Multiple inducible VTs were observed with mechanism consistent with scar-mediated re-entry in all VTs. Voltage maps showed widespread and confluent right ventricular scarring. Left ventricular scarring was patchy with a predilection for the basal septum, anterior wall, and perivalvular regions. Epicardial right ventricular scar overlay and exceeded the region of corresponding endocardial scar. After ≥1 procedures, ablation abolished ≥1 inducible VT in 90% and eliminated VT storm in 78% of patients; however, multiple residual VTs remained inducible. Failure to abolish all inducible VTs was because of septal intramural circuits or extensive right ventricular scarring. Multiple procedure VT-free survival was 37% at 1 year, but VT control was achievable in the majority of patients with fewer antiarrhythmic drugs compared with preablation (2.1±0.8 versus 1.1±0.8; P<0.001). Patients with cardiac sarcoidosis and VT exhibit ventricular substrate characterized by confluent right ventricular scarring and patchy left ventricular scarring capable of sustaining a large number of re-entrant circuits. Catheter ablation is effective in terminating VT storm and eliminating ≥1 inducible VT in the majority of patients, but recurrences are common. Ablation in conjunction with antiarrhythmic drugs can help palliate VT in this high-risk population. © 2014 American Heart Association, Inc.
Li, Shi-jun; Wang, Tao; Wang, Lin; Pang, Zhan-qi; Ma, Ben; Li, Ya-wen; Yang, Jian; Dong, He
Abstract Pheochromocytomas are neuroendocrine tumors, and its cardiac involvement may include transient myocardial dysfunction, acute coronary syndrome (ACS), and even ventricular arrhythmias. A patient was referred for evaluation of stuttering chest pain, and his electrocardiogram showed T-wave inversion over leads V1 to V4. Coronary angiography showed 90% stenosis in the mid-left anterior descending coronary artery (LAD), which was stented. Five days later, the patient had ventricular tachycardia, and severe hypertension, remarkable blood pressure fluctuation between 224/76 and 70/50 mm Hg. The patient felt abdominal pain and his abdominal ultrasound showed suspicious right adrenal gland tumor. Enhanced computed tomography of adrenal gland conformed that there was a tumor in right adrenal gland accompanied by an upset level of aldosterone. The tumor was removed by laparoscope, and the pathological examination showed pheochromocytoma. After the surgery, the blood pressure turned normal gradually. There was no T-wave inversion in lead V1-V4. Our case illustrates a rare pheochromocytoma presentation with a VT and resembling ACS. In our case, the serious stenosis in the mid of LAD could be explained by worsen the clinical course of myocardial ischemia or severe coronary vasospasm by the excessive amounts of catecholamines released from the tumor. Coronary vasospasm was possible because he had no classic coronary risk factors (e.g. family history and smoking habit, essential hypertension, hyperglycemia and abnormal serum lipoprotein, high body mass index). Thus, pheochromocytoma was missed until he revealed the association of his symptoms with abdominalgia. As phaeochromocytomas that present with cardiovascular complications can be fatal, it is necessary to screen for the disease when patients present with symptoms indicating catecholamine excess. PMID:27057898
Whinnery, J E; Laughlin, M H; Uhl, G S
The environment of the advanced fighter aircraft represents a unique combination of stressful factors. Each of the individual stresses is hazardous, with the summation of these factors possibly resulting in an additional risk for sudden in-flight incapacitation. Advanced fighter aircraft are capabble of producing both rapid onset and high sustained +GZ forces which, on occasion, can exceed the tolerance limits of the pilot. The +GZ forces encountered during aerial combat maneuvering are physiologically stressful and have a profound effect on the regulatory mechanisms of the body. The influence of these stresses, including +GZ stress, on the autonomic nervous system is complex. The overall normal regulation of the cardiovascular system depends on a balance between both branches of the autonomic nervous system. An imbalance between sympathetic and parasympathetic tone can result in cardiac dysrhythmias and symptoms not conducive to safe and effective flight. An episode of ventricular tachycardia, coincident with an episode of loss of consciousness, was observed in an apparently healthy aircrewman during +GZ stress on the USAF School of Aerospace Medicine human centrifuge. The implications of autonomic imbalance in the production of similar potentially hazardous dysrhythmias and symptoms in the multistress environment deserve more in-depth investigation.
Ventricular tachycardia (VT) is life-threatening subgroup of wide QRS complex tachycardia (WCT). VT is usually associated with structural heart diseases, but it can occur in the absence of any cardiovascular diseases. Adverse cardiac effect of sodium bicarbonate in healthy subjects is not well described. A 30-year-old healthy man with excessive intake of sodium bicarbonate-related VT is presented. He was using sodium bicarbonate during last 2 months to lose weight. He has no risk factors and any cardiovascular or systemic diseases. After intravenous administration of amiodarone, tachycardia ended and his rhythm converted to sinus rhythm with normal electrocardiogram. Patient is asymptomatic, and no VT was observed without any medications at 1 year of follow-up.
Clyne, Christopher A; Athar, Haris; Shah, Anuj; Kahr, Rosemarie; Rentas, Angel
Acute and long-term success of catheter ablation of right ventricular outflow tract tachycardia (RVOT VT) may be limited by the inability to reproduce the arrhythmia at the time of activation (AM) and pace mapping (PM). We have observed early initiation of the clinical VT when subtherapeutic radiofrequency (RF) energy was applied to the target area (TA), defined as a 2-cm(2) area around a pace match. We describe a novel approach using thermal mapping (TM) to guide the ablation of RVOT VT. Thirteen patients (10 female, mean age 46.2 +/- 13.7 years) with symptomatic VT of left bundle branch block (LBBB) inferior axis morphology and no structural heart disease underwent standard electrophysiologic evaluation with PM (n = 13), AM (n = 13), and 3D noncontact mapping (n = 4). Thermal mapping was performed after standard techniques failed to induce stable sustained VT for mapping in all 13 patients: RF was applied for 5-10 seconds in the TA to achieve a tip temperature of 45-50 degrees C. At sites where morphologically consistent with the clinical VT was induced, RF was applied at target temperature between 50 and 60 degrees C for 30-60 seconds. TM was repeated before and after intravenous Isoproterenol infusion until no further VT could be induced by low temperature application. Noninducibility was achieved in all 13 patients. During a mean follow-up of 29 months (9-69 months), all patients remain arrhythmia-free, off antiarrhythmic medications. Thermal mapping is a safe and effective adjunctive technique for the mapping and ablation of RVOT VT when sustained tolerated clinical VT cannot be induced.
Segal, Oliver R.; Chow, Anthony W.C.; Peters, Nicholas S.; Davies, D. Wyn
Background Precise mechanisms that initiate ventricular tachycardia (VT) in the intact infarcted human heart have not been defined. Objective The purpose of this study was to investigate the mechanisms that underlie human postinfarct VT initiation. Methods Noncontact mapping of the left ventricle was performed in 9 patients (age 67.1 ± 7.8 years, ejection fraction 34.4% ± 5%) with previous myocardial infarction and sustained monomorphic VT. Results Circuits in which ≥30% of the diastolic pathway (DP) could be defined were identified in 12 VTs (cycle length 357 ± 60 ms). Eighteen VT episodes were initiated with pacing, and one occurred spontaneously. Ten complete and two partial circuits were mapped (89% ± 25% of the DP). In all complete circuits, pacing led to the development of unidirectional conduction block at the location of the subsequent VT exit site and the formation of functional block creating a border(s) for subsequent DP. Wavefront velocity in the DP region slowed from 1.22 ± 0.2 m/s during sinus rhythm to 0.59 ± 0.14 m/s during VT (P <.005). In 11 initiation episodes, lines of functional block and areas of slow conduction developed progressively over one to six reentrant cycles before a stable DP was established and sustained monomorphic VT ensued. The formation of unidirectional or functional lines of block was not identified during identical pacing protocols that failed to initiate VT (n = 14). Conclusion Initiation of sustained monomorphic VT requires the development of unidirectional block and formation of lines of functional block creating borders for a DP in areas of slow conduction. A transitional stage often exists during the initiation process before a stable VT circuit is established. PMID:20129286
Xing, Dezhi; Chaudhary, Ashok K.; Miller, Francis J.; Martins, James B.
Background Focal ventricular tachycardia (VT) in acute myocardial ischemia is closely related to triggered activity (TA), which may be blocked by scavenging reactive oxygen species (ROS). Objective This study analyzed effects of acutely administered ROS scavenger-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) on VT in vivo and TA in vitro. Methods Forty-three alpha chloralose anesthetized dogs with coronary artery occlusion were studied. 3-D activation mapping helped to locate the origin of focal or reentrant VT. TEMPO (30mg/kg, iv) or vehicle was given. Endocardium excised from the site of origin of VT was studied using standard microelectrode techniques and measures of ROS. Results Reentry and focal VT induction were both highly reproducible. TEMPO blocked focal VT in 6 of 11 dogs (p<0.05), but 9 of 9 dogs with reentrant VT continued to have VT re-induced after TEMPO. TEMPO did not alter effective refractory period (168±3 to 171±3 ms), mean blood pressure (88±3 to 81±3 mmHg), and size of ischemia (42±3% vs 40±4%). In vitro, TEMPO (10−3M, n=14) produced no change in action potentials. Nevertheless, TA was reversibly attenuated from 5.3±1.1 to 0.4±0.4 complexes with TEMPO (n=15, p<0.05). Lucigenin-enhanced chemilumenescence and dihydroethidium staining showed increased ROS in ischemic endocardium; TEMPO dramatically reduced ROS in ischemic sites. Conclusions TEMPO, a scavenger of ROS, prevented triggered activity associated with focal VT during myocardial ischemia in areas of increased ROS. Antioxidant therapy may play an important role in blockade of focal VT under the conditions of myocardial ischemia. PMID:19324315
Purkinje-related monomorphic ventricular tachycardias (VTs) can be classified into four distinct groups: (1) verapamil-sensitive left fascicular VT, (2) Purkinje fiber-mediated VT post infarction, (3) bundle branch reentry (BBR) and interfascicular reentry VTs, and (4) focal Purkinje VT. There are three subtypes of fascicular VTs: (1) left posterior fascicular VT with a right bundle branch block (RBBB) configuration and superior axis; (2) left anterior fascicular VT with an RBBB configuration and right-axis deviation; and (3) upper septal fascicular VT with a narrow QRS configuration. The mechanism of the fascicular VT is macroreentry. While the antegrade limb of the circuit is a midseptal abnormal Purkinje fiber in the anterior and posterior fascicular VTs, the antegrade limb of the upper septal fascicular VT is both the anterior and posterior fascicles, and the retrograde limb is a midseptal abnormal Purkinje fiber. Purkinje fiber-mediated VT post infarction also exhibits verapamil sensitivity, and the surviving muscle bundles within the myocardium and Purkinje system are components of the reentry circuit. BBR-VT and interfascicular reentry VT are amenable to being cured by the creation of bundle or fascicular block. The mechanism of focal Purkinje VT is abnormal automaticity from the distal Purkinje system, and the ablation target is the earliest Purkinje activation during the VT. It is difficult to distinguish verapamil-sensitive fascicular VT from focal Purkinje VT by the 12-lead electrocardiogram; however, focal Purkinje VT is not responsive to verapamil . The recognition of the heterogeneity of these VTs and their unique characteristics should facilitate an appropriate diagnosis and therapy.
Cano, Oscar; Hutchinson, Mathew; Lin, David; Garcia, Fermin; Zado, Erica; Bala, Rupa; Riley, Michael; Cooper, Joshua; Dixit, Sanjay; Gerstenfeld, Edward; Callans, David; Marchlinski, Francis E
The aim of the study was to define the epicardial substrate and ablation outcome in patients with left ventricular nonischemic cardiomyopathy (NICM) and suspected epicardial ventricular tachycardia (VT). Ventricular tachycardia in NICM often originates from the epicardium. Twenty-two patients with NICM underwent detailed endocardial and epicardial bipolar voltage maps and VT ablation for suspected epicardial VT. Eight patients with normal hearts and idiopathic VT served to define normal epicardial electrograms. Low-voltage regions were also assessed for wide (>80 ms), split, or late electrograms. Normal epicardial bipolar voltage was identified as >1.0 mV on the basis of the reference population. Confluent low-voltage areas were present in 18 epicardial (82%) and 12 endocardial (54%) maps and were typically over basal lateral LV. In the 18 patients with epicardial VT on the basis of activation/pacemapping, the mean epicardial area was greater than the endocardial low-voltage area (55.3 +/- 33.5 cm(2) vs. 22.9 +/- 32.4 cm(2), p < 0.01). Epicardial low-voltage areas showed 49.7% wide (>80 ms), split, and/or late electrograms rarely seen in the reference patients (2.3%). During follow-up of 18 +/- 7 months, ablation resulted in VT elimination in 15 of 21 patients (71%) including 14 of 18 patients (78%) with epicardial VT. In patients with NICM and VT of epicardial origin, the substrate is characterized by areas of basal LV epicardial > endocardial bipolar low voltage. The electrograms in these areas are not only small (<1.0 mV) but wide (>80 ms), split, and/or late, and help identify the substrate targeted for successful ablation. 2009 by the American College of Cardiology Foundation
Noh, C. I.; Song, J. Y.; Kim, H. S.; Choi, J. Y.; Yun, Y. S.
OBJECTIVE--To emphasize the importance of ventricular tachycardia associated with repolarisation abnormality in syncope associated with exercise. DESIGN--Retrospective analysis of data on children presenting with syncope between 1985 and 1993. PATIENTS--5 apparently normal children with recurrent exercise related syncope associated with electrocardiographically abnormal TU complexes. RESULTS--3 children were diagnosed as having an intermediate form of the long QT syndrome and catecholamine sensitive ventricular tachycardia because the abnormal TU complexes were associated with polymorphic ventricular tachycardia that was not typical of torsades de pointes. Tachycardia was induced by exercise in all patients and by isoprenaline in the one patient who was tested. One patient also had sinus node dysfunction. One child had incessant salvos of polymorphic ventricular arrhythmias and intermittent abnormal TU complexes suggestive of repolarisation abnormalities. The other had typical congenital long QT syndrome. Treatment was effective in three patients; two patients took a beta blocker alone and one took a beta blocker and low doses of amiodarone. One patient died suddenly, death being associated with sinus node dysfunction. In one patient with incessant ventricular arrhythmias treatment with a beta blocker, amiodarone, or Ic drugs was ineffective and always associated with proarrhythmia or syncope. He was not given further treatment and was asymptomatic despite having mild cardiomegaly. CONCLUSIONS--Ventricular tachycardia associated with repolarisation abnormality was an important cause of exercise related syncope in apparently normal children. TU complex abnormalities can be identified by repeated electrocardiography. beta Blockers are effective in preventing recurrent episodes. The role of amiodarone in this type of ventricular tachycardia needs further evaluation. PMID:7626354
Hou, Bingbo; Zheng, Lihui; Niu, Guodong; Wu, Lingmin; Qiao, Yu; Sun, Wei; Ding, Ligang; Chen, Gang; Zhang, Shu; Liew, Reginald; Yao, Yan
This study was aimed to report the characteristics and treatment of ventricular tachycardia (VT) following surgical treatment of pulmonary stenosis with intact ventricular septum. Five patients underwent radiofrequency catheter ablation for sustained monomorphic left bundle branch block (LBBB) type VT who previously underwent surgical treatment of pulmonary stenosis. Except stimulation, voltage and activation mapping was performed using three-dimensional (3D) electro-anatomic mapping and ablation was applied accordingly. Four VTs were induced during EP study. Two VTs were focal and the earliest activity was targeted in the right ventricular apex (RVA). The other two VTs were reentrant and the critical isthmus located in the mid-lateral wall and anterior wall of right ventricle, respectively. Ablation abolished all inducible VTs in four patients. In the patient whose VT was non-inducible, radiofrequency (RF) energy was delivered to the RVA where pacing mapping matched the clinical VT. One focal VT recurred 60 months after the initial RF ablation. Repeat mapping and ablation was performed and no VT recurred over a 24-month period. The mechanism of VT following surgical treatment of pulmonary stenosis can be either focal or reentrant. Ablation of this subgroup of VT is feasible. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: firstname.lastname@example.org.
Costello, John P; He, Dingchao; Greene, Elizabeth A; Berul, Charles I; Moak, Jeffrey P; Nath, Dilip S
A full-term male neonate presented with cyanosis upon delivery and was subsequently diagnosed with d-transposition of the great arteries, ventricular septal defect, and restrictive atrial septal defect. Following initiation of intravenous prostaglandins and balloon atrial septostomy, an arterial switch operation was performed on day 3 of life. The postoperative course was complicated by intractable ventricular tachycardia that was refractory to lidocaine, amiodarone, esmolol, fosphenytoin, and mexiletine drug therapy. Ventricular tachycardia was suppressed with overdrive atrial pacing but recurred upon discontinuation. Seven weeks postoperatively, radiofrequency catheter ablation was performed due to hemodynamically compromising persistent ventricular tachycardia refractory to medical therapy. The ventricular tachycardia was localized to the inferior-lateral right ventricular outlet septum. The procedure was successful without complications or recurrence. Antiarrhythmics were discontinued after the ablation procedure. Seven days after the ablation, a different, slower fascicular rhythm was noted to compete with the infant's sinus rhythm. This was consistent with the preablation amiodarone having reached subtherapeutic levels given its very long half-life. The patient was restarted on oral beta blockers and amiodarone. The patient was subsequently discharged home in predominantly sinus rhythm with intermittent fascicular rhythm.
Baldinger, Samuel H; Stevenson, William G; John, Roy M
This article summarizes current understanding of the arrhythmia substrate and effect of catheter ablation for infarct-related ventricular tachycardia, focusing on recent findings. Clinical studies support the use of catheter ablation earlier in the course of ischemic disease with moderate success in reducing arrhythmia recurrence and shocks from implantable defibrillators, although mortality remains unchanged. Ablation can be lifesaving for patients presenting with electrical storm. Advanced mapping systems with image integration facilitate identification of potential substrate, and several different approaches to manage hemodynamically unstable ventricular tachycardia have emerged. Novel ablation techniques that allow deeper lesion formation are in development. Catheter ablation is an important therapeutic option for preventing or reducing episodes of ventricular tachycardia in patients with ischemic cardiomyopathy. Present technologies allow successful ablation in the majority of patients, even when the arrhythmia is hemodynamically unstable. Failure of the procedure is often because of anatomic challenges that will hopefully be addressed with technological progress.
Misaki, T; Watanabe, G; Iwa, T; Watanabe, Y
From November 1973, 454 patients with Wolff-Parkinson-White syndrome underwent surgical ablation of accessory pathways. Overall curative rate was 94% in our series including 65 cases of simultaneous surgical repair for combined heart diseases. In recent months, radiofrequency catheter ablation was applied in 7 cases. There has been 2 failures, which have taken more than 2 hours of radiation exposure and have required surgery. There has been 47 patients who underwent surgical ablation for non-ischemic ventricular tachycardia. Forty cases (85%) had a successful outcome of surgical ablation and another 2 cases required DC catheter ablation postoperatively to eliminate ventricular tachycardias. In conclusion, radiofrequency ablation of WPW syndrome in patients without combined heart disease or multiple accessory pathways is feasible. Surgical ablation is effective and safe technique compared with catheter ablation in patients with ventricular tachycardia.
Kresimir, Kordic; Sime, Manola; Ivan, Zeljkovic; Ivica, Benko; Nikola, Pavlovic
Fascicular left ventricular tachycardia (VT) is the second most frequent idiopathic left VT in the setting of a structurally normal heart. Catheter ablation is curative in most patients with low complication rates. We report a case of ostial left anterior descending coronary artery (LAD) occlusion during fascicular ventricular tachycardia ablation. Dissection was the most likely cause of LAD obstruction. To the authors' best knowledge, this is the first case reporting selective LAD dissection during electrophysiology study with no left main coronary artery (LMCA) affection.
Tchou, Patrick; Tarakji, Khaldoun; Kanj, Mohamed
The sequence of changes in the QRS morphology and the accompanying cycle lengths of the tachycardia confirm that the reentrant circuit involves the left ventricular myocardium as well as the His Purkinje system as part of the reentrant circuit. The reentrant propagation likely goes from local left ventricular myocardium into a slowly conducting, verapamil-sensitive tissue, which then connects into the inferior fascicle. This case demonstrates that fascicular reentrant tachycardias can generate different QRS morphologies depending on the path of breakout into the myocardium.
Kusa, Shigeki; Miller, Marc A; Whang, William; Enomoto, Yoshinari; Panizo, Jorge G; Iwasawa, Jin; Choudry, Subbarao; Pinney, Sean; Gomes, Anthony; Langan, Noelle; Koruth, Jacob S; d'Avila, Andre; Reddy, Vivek Y; Dukkipati, Srinivas R
Although percutaneous left ventricular assist devices (pLVADs) facilitate mapping and ablation of hemodynamically unstable ventricular tachycardia (VT), there is limited data whether clinical outcomes are improved. We sought to retrospectively compare the outcomes of patients undergoing scar-related VT ablation with and without pLVAD support. The study population comprised 194 patients (109 pLVAD and 85 non-pLVAD). The pLVAD group more often had dilated cardiomyopathy (33% versus 13%; P=0.001), New York Heart Association heart failure class ≥III (51% versus 25%; P<0.001), lower left ventricular ejection fractions (26±10% versus 39±16%; P<0.001), and electrical storm (49% versus 34%; P=0.04). Procedure times (422±112 versus 330±92 minutes; P<0.001), postablation VT inducibility (20% versus 7%; P=0.02), and length of subsequent hospitalization (median 6 versus 4 days; P=0.001) were all higher in the pLVAD group. During median follow-up of 215 days, the primary end point (recurrent VT, heart transplantation, or death) occurred in 36% of the pLVAD versus 26% of the non-pLVAD groups (P=0.14). After propensity matching for differences between groups, no differences were seen between groups for both acute procedural outcomes and the primary end point. In this large single-center scar-related VT ablation experience, despite the worse clinical status of the patients selected for pLVAD support, clinical outcomes were better than expected and were similar to healthier patients not receiving hemodynamic support. Patients with dilated cardiomyopathy presenting with electrical storm, advanced heart failure, and severe left ventricular dysfunction most frequently received hemodynamic support during VT ablation. © 2017 American Heart Association, Inc.
Lamberti, Filippo; Di Clemente, Francesca; Remoli, Romolo; Bellini, Cesare; De Santis, Antonella; Mercurio, Marina; Dottori, Serena; Gaspardone, Achille
Catheter ablation is the treatment of choice for many patients with idiopathic ventricular tachycardia (VT). Unfortunately, conventional catheter ablation is guided by fluoroscopy, which is associated with a small but definite radiation risk for patients and laboratory personnel. The aim of our study is to assess feasibility, success rate and safety of idiopathic VT ablation procedure performed without the use of fluoroscopy. Nineteen consecutive patients undergoing idiopathic VT ablation at our institution have been included. The ablation procedures were performed under the guidance of electroanatomical mapping (EAM) system and intracardiac echocardiography (ICE). Nineteen patients (mean age 38.7 years) underwent ablation procedure for idiopathic VT. Twelve (63%) had outflow tract VT, 3 (18%) fascicular tachycardia, 2 (11%) peri-tricuspidal VT, 1 (5%) peri-mitral VT, and 1 (5%) lateral left free-wall VT. The mean procedural time was 170.2 ± 45.7 min. No fluoroscopy was used in any procedural phase. Acute success rate was 100%. No complication was documented in any patients. After a mean follow up of 18 ± 4 months, recurrences occurred in 2 patients. In our preliminary experience idiopathic VT ablation without the use of fluoroscopy was feasible and safe, using a combination of EAM and ICE. Success rate was excellent with no complication. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Arevalo, Hermenegild; Plank, Gernot; Helm, Patrick; Halperin, Henry; Trayanova, Natalia
Ventricular tachycardia, a life-threatening regular and repetitive fast heart rhythm, frequently occurs in the setting of myocardial infarction. Recently, the peri-infarct zones surrounding the necrotic scar (termed gray zones) have been shown to correlate with ventricular tachycardia inducibility. However, it remains unknown how the latter is determined by gray zone distribution and size. The goal of this study is to examine how tachycardia circuits are maintained in the infarcted heart and to explore the relationship between the tachycardia organizing centers and the infarct gray zone size and degree of heterogeneity. To achieve the goals of the study, we employ a sophisticated high-resolution electrophysiological model of the infarcted canine ventricles reconstructed from imaging data, representing both scar and gray zone. The baseline canine ventricular model was also used to generate additional ventricular models with different gray zone sizes, as well as models in which the gray zone was represented as different heterogeneous combinations of viable tissue and necrotic scar. The results of the tachycardia induction simulations with a number of high-resolution canine ventricular models (22 altogether) demonstrated that the gray zone was the critical factor resulting in arrhythmia induction and maintenance. In all models with inducible arrhythmia, the scroll-wave filaments were contained entirely within the gray zone, regardless of its size or the level of heterogeneity of its composition. The gray zone was thus found to be the arrhythmogenic substrate that promoted wavebreak and reentry formation. We found that the scroll-wave filament locations were insensitive to the structural composition of the gray zone and were determined predominantly by the gray zone morphology and size. The findings of this study have important implications for the advancement of improved criteria for stratifying arrhythmia risk in post-infarction patients and for the development of
Luther, Vishal; Linton, Nick W F; Jamil-Copley, Shahnaz; Koa-Wing, Michael; Lim, Phang Boon; Qureshi, Norman; Ng, Fu Siong; Hayat, Sajad; Whinnett, Zachary; Davies, D Wyn; Peters, Nicholas S; Kanagaratnam, Prapa
Post-infarct ventricular tachycardia is associated with channels of surviving myocardium within scar characterized by fractionated and low-amplitude signals usually occurring late during sinus rhythm. Conventional automated algorithms for 3-dimensional electro-anatomic mapping cannot differentiate the delayed local signal of conduction within the scar from the initial far-field signal generated by surrounding healthy tissue. Ripple mapping displays every deflection of an electrogram, thereby providing fully informative activation sequences. We prospectively used CARTO-based ripple maps to identify conducting channels as a target for ablation. High-density bipolar left ventricular endocardial electrograms were collected using CARTO3v4 in sinus rhythm or ventricular pacing and reviewed for ripple mapping conducting channel identification. Fifteen consecutive patients (median age 68 years, left ventricular ejection fraction 30%) were studied (6 month preprocedural implantable cardioverter defibrillator therapies: median 19 ATP events [Q1-Q3=4-93] and 1 shock [Q1-Q3=0-3]). Scar (<1.5 mV) occupied a median 29% of the total surface area (median 540 points collected within scar). A median of 2 ripple mapping conducting channels were seen within each scar (length 60 mm; initial component 0.44 mV; delayed component 0.20 mV; conduction 55 cm/s). Ablation was performed along all identified ripple mapping conducting channels (median 18 lesions) and any presumed interconnected late-activating sites (median 6 lesions; Q1-Q3=2-12). The diastolic isthmus in ventricular tachycardia was mapped in 3 patients and colocated within the ripple mapping conducting channels identified. Ventricular tachycardia was noninducible in 85% of patients post ablation, and 71% remain free of ventricular tachycardia recurrence at 6-month median follow-up. Ripple mapping can be used to identify conduction channels within scar to guide functional substrate ablation. © 2016 American Heart Association
Briceño, David F; Romero, Jorge; Gianni, Carola; Mohanty, Sanghamitra; Villablanca, Pedro A; Natale, Andrea; Di Biase, Luigi
Ventricular arrhythmias are a frequent cause of mortality in patients with ischemic cardiomyopathy and nonischemic cardiomyopathy. Scar-related reentry represents the most common arrhythmia substrate in patients with recurrent episodes of sustained ventricular tachycardia (VT). Initial mapping of scar-related VT circuits is focused on identifying arrhythmogenic tissue. The substrate-based strategies include targeting late potentials, scar dechanneling, local abnormal ventricular activities, core isolation, and homogenization of the scar. Even though substrate-based strategies for VT ablation have shown promising outcomes for patients with structural heart disease related to ischemic cardiomyopathy, the data are scarce for patients with nonischemic substrates.
DeGiorgio, Andrew C; Desso, Tamara E; Lee, Lance; DeGiorgio, Christopher M
We report a case of sustained ventricular tachycardia following the initiation of lacosamide as adjunctive epilepsy treatment. A 49-year-old male with intractable frontal lobe seizures experienced severe ventricular tachycardia following the addition of 400 mg lacosamide to his existing regimen of carbamazepine, lamotrigine, clonazepam, and valproate. The tachycardia occurred during a cardiac stress test; stress tests prior to initiation of lacosamide were normal. Conduction defects, including QRS prolongation, persisted during hospitalization until lacosamide was discontinued. The patient had no prior history of cardiac arrhythmia but did possess cardiac risk factors, including hypertension, hypercholesterolemia, and low heart rate variability. This case represents one part of a growing body of literature suggesting a link between arrhythmia and use of lacosamide, which enhances slow inactivation of sodium channels in both the brain and the heart. We believe further study may be necessary to assess the safety of lacosamide in epilepsy patients with cardiac risk factors.
El-Damaty, Ahmed; Sapp, John L
Catheter ablation has evolved remarkably over the last 2 decades, bringing nonpharmacologic therapy to complex arrhythmias like atrial fibrillation and scar-related ventricular tachycardia. As our therapeutic options have increased for patients with ventricular tachycardia, choosing the right therapy for the right patient has become more complex. Ablation carries acute and perhaps longer-term procedural risk and variable success, whereas drug therapy likewise is limited by both side-effects and efficacy. Early randomized trials of catheter ablation for ventricular tachycardia and multicenter experiences have recently been published, and further studies are underway to define the appropriate application of this therapy. Randomized trials have demonstrated that catheter ablation can reduce ventricular tachycardia episodes with relatively low risk. Multicenter experience has demonstrated a moderate risk of serious procedural adverse events in this very sick population, but ablation has never been compared directly with antiarrhythmic drug therapy. There is still little evidence to clarify the relative merits of antiarrhythmic drug therapy in comparison with ablation. The optimal role of either therapy will remain uncertain until the completion of trials currently in progress. Until further evidence is available, most clinicians advocate first-line antiarrhythmic drug therapy, and reserve catheter ablation for when this fails or is not tolerated.
Zaman, L; Castellanos, A; Saoudi, N C; Stafford, W J; Trohman, R G; Interian, A; Myerburg, R J
The physiology of entrainment of orthodromic circus movement tachycardia (CMT) was studied using ventricular pacing during 18 episodes of induced CMT in 7 patients with atrioventricular (AV) accessory pathways. The first paced impulse was delivered as late as possible in the tachycardia cycle (mean 88 +/- 5% of the spontaneous cycle length [CL]). Entrainment was demonstrated by the following criteria: 1:1 retrograde conduction via the accessory pathway; capture of atrial, ventricular and His bundle electrograms at the pacing rate; and resumption of tachycardia at its previous rate after cessation of pacing. The number of ventricular paced impulses ranged from 5 to 14 (mean 8 +/- 3), and entrainment occurred in 2 to 7 paced cycles (mean 4 +/- 2). Orthodromic activation of a major part of the reentry circuit (manifest entrainment) was demonstrated during 9 episodes by the occurrence of His bundle electrogram preceding the first CMT QRS at the time anticipated from the last paced beat. In the 9 other episodes, persistent retrograde His bundle activation and AV nodal penetration by each paced impulse caused a delay (mean 79 +/- 25 ms) in activation of the His bundle preceding the first CMT QRS after the last paced beat. The mean pacing CL achieving manifest entrainment was 92 +/- 3% of the tachycardia CL, compared with 84 +/- 3% for retrograde AV nodal penetration (p less than 0.01). In conclusion, manifest entrainment of orthodromic CMT can be demonstrated by ventricular pacing at very long CLs; shorter CLs may cause CMT termination due to retrograde AV nodal penetration.
Giaccardi, Marzia; Chiodi, Leandro; Del Rosso, Attilio; Colella, Andrea
Situs viscerum inversus totalis (SVIT) is a congenital disorder characterized by mirror reversal of the thoracic and abdominal organs. Different studies have shown that the ablation procedure can be performed without fluoroscopy with safety and effectiveness, in the setting of supraventricular tachycardia. We successfully performed an anatomical map and a radiofrequency catheter ablation of ventricular arrhythmia in a patient with SVIT without fluoroscopy.
... fast heartbeat. Common types of tachycardia include: Atrial fibrillation. Atrial fibrillation is a rapid heart rate caused by chaotic, ... rapid, uncoordinated, weak contractions of the atria. Atrial fibrillation may be temporary, but some episodes won't ...
Enjoji, Yoshihisa; Mizobuchi, Masahiro; Shibata, Kensaku; Ono, Tsuyoshi; Funatsu, Atsushi; Kanbayashi, Daisuke; Kobayashi, Tomoko; Nakamura, Shigeru
We report a rare case of bundle branch reentrant ventricular tachycardia [BBRVT]. A 67-year-old female was admitted for management of wide QRS tachycardia (right bundle branch block [RBBB] and a southwest axis). The mapping procedure revealed the tachycardia circuit consisted of the left anterior fascicle (LAF) as an antegrade, and the right bundle as a retrograde pathway. She presented RBBB during sinus rhythm. LAF ablation changed the tachycardia configuration to a northwest axis and prolonged the cycle length. Left posterior fascicle ablation terminated the tachycardia, and complete atrioventricular block occurred, which showed the unidirectional conduction over the right bundle.
Kocaş, Cüneyt; Türkmen, Yusuf; Çetinkal, Gökhan; Doğan, Sait Mesut
Amantadine hydrochloride is an antiviral agent that is also effective in the treatment of Parkinson's disease. In the literature, cardiac arrhythmia is reported in toxic doses of amantadine, but in this paper we report a patient with right ventricular outflow tract (RVOT) tachycardia after an initial dose of amantadine. A 47-year-old female patient was admitted to the emergency department with the complaint of palpitation and dizziness after taking 200 mg amantadine. A 12-lead standard ECG showed wide QRS complex tachycardia with a heart rate of 167/min. The wide QRS complex tachycardia had an inferior axis and left bundle branch block morphology, compatible with RVOT ventricular tachycardia (RVOT-VT). Tachycardia terminated spontaneously and sinus ECG was completely normal. No arrhythmia was inducible at the electrophysiological study. To the best of our knowledge, this is the first case in the literature to describe RVOT-VT after amantadine intake. Amantadine may cause RVOT-VT as well as other cardiac arrhythmias.
Xie, Yuanfang; Grandi, Eleonora; Bers, Donald M; Sato, Daisuke
Ventricular tachycardia (VT) and fibrillation (VF) are the most lethal cardiac arrhythmias. The degeneration of VT into VF is associated with the breakup of a spiral wave of the action potential in cardiac tissue. β-Adrenergic (βAR) signalling potentiates the L-type Ca current (ICaL) faster than the slow delayed rectifier potassium current (IKs), which transiently prolongs the action potential duration (APD) and promotes early after depolarizations. In this study, we aimed at investigating how βAR signalling affects the transition from VT to VF. We used a physiologically detailed computer model of the rabbit ventricular myocyte in a two-dimensional tissue to determine how spiral waves respond to βAR activation following administration of isoproterenol. A simplified mathematical model was also used to investigate the underlying dynamics. We found that the spatiotemporal behaviour of spiral waves strongly depends on the kinetics of βAR activation. When βAR activation is rapid, a stable spiral wave turns into small fragments and its electrocardiogram reveals the transition from VT to VF. This is due to the transiently steepened APD restitution induced by the faster activation of ICaL vs. IKs upon sudden βAR activation. The spiral wave may also disappear if its transient wavelength is too large to be supported by the tissue size upon sudden strong βAR activation that prolongs APD transiently. When βAR activation is gradual, a stable spiral wave remains such, because of more limited increase in both APD and slope of APD restitution due to more contemporaneous ICaL and IKs activation. Changes in APD restitution during βAR activation revealed a novel transient spiral wave dynamics; this spatiotemporal characteristic strongly depends on the protocol of isoproterenol application.
Rao, Hygriv B; Yu, Ricky; Chitnis, Nishad; DO, Duc; Boyle, Noel G; Shivkumar, Kalyanam; Bradfield, Jason S
The safety of ventricular tachycardia (VT) ablation in patients with laminated left ventricular (LV) thrombus has not been examined. Patients with laminated LV thrombus on transthoracic echocardiogram who underwent scar-mediated VT ablation at two centers from 2010 to 2013 were retrospectively analyzed. All patients had failed medical therapy. Acute procedural outcomes, complications, and clinical outcomes at 1 year were assessed. Eight patients (four ischemic, four nonischemic cardiomyopathy) underwent VT ablation in the presence of laminated intracavitary thrombus. Six out of eight (75%) had electrical storm (ES). The mapping and ablation approach was LV endocardial-only in three patients, epicardial-only in two, combined epicardial-RV endocardial in two, and combined epicardial-LV endocardial in one. Major complication (ischemic stroke) occurred in one patient 9 days post-procedure. There was no procedural mortality. Complete acute procedural success (noninducibility of any VT after ablation) was achieved in five (63%), and partial success (ablation of only clinical VT) in an additional three (37%). At 1 year, freedom from VT and survival were achieved in six (75%) and seven (88%) patients, respectively. Initial data suggest that ablation of VT in the presence of intracavitary thrombus is feasible, is associated with a similar success rate to historical studies in patients without thrombus, and has an acceptable risk of complications given the high-risk nature of patients with ES. Further data are needed; however, the presence of a laminated thrombus should not necessarily preclude ablation in patients who have failed medical therapy for VT in whom ablation is otherwise indicated. © 2015 Wiley Periodicals, Inc.
Morin, Daniel P; Mauer, Andreas C; Gear, Kathleen; Zareba, Wojciech; Markowitz, Steven M; Marcus, Frank I; Lerman, Bruce B
The 2 predominant causes of ventricular tachycardia (VT) arising from the right ventricle are arrhythmogenic right ventricular cardiomyopathy (ARVC) and idiopathic VT arising from the right ventricular outflow tract (RVOT). These arrhythmias can be adrenergically mediated and may be difficult to distinguish clinically. A minor criterion for the diagnosis of ARVC is T-wave inversion (TWI) in the right precordial leads during sinus rhythm. However, there have been reports of precordial TWI identified in patients with RVOT tachycardia. The purpose of this study was to determine whether patterns of precordial TWI could differentiate between the 2 groups. A multicenter registry of 229 patients with VT of right ventricular origin was evaluated. After appropriate exclusions (n = 29), 79 patients (58% men, mean age 40 +/- 14 years) had ARVC, and 121 patients (41% men, mean age 48 +/- 14 years) had RVOT tachycardia. During sinus rhythm, 37 patients (47%) with ARVC and 5 patients (4%) with RVOT tachycardia had TWI in leads V(1) to V(3). For the diagnosis of ARVC, TWI in leads V(1) to V(3) had sensitivity of 47% and specificity of 96%. In conclusion, in patients with VT of right ventricular origin, the presence of TWI in electrocardiographic leads V(1) to V(3) supports the diagnosis of ARVC.
Park, Kyoung-Min; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho
A 70-year-old patient with 3-vessel coronary artery disease and a left ventricular aneurysm underwent coronary artery bypass grafting, together with a surgical anterior ventricular endocardial restoration (SAVER) procedure. Four days later, he suddenly developed recurrent sustained and nonsustained polymorphic ventricular tachycardia, preceded by monomorphic ventricular premature contractions, and did not respond to any antiarrhythmic drug, including lidocaine, esmolol, or amiodarone. Repeated electrical cardioversion procedures were performed (28 in total). Mapping was performed to target the earliest site of activation in the left ventricle during the ventricular premature contractions, a site where the premature beats were preceded by Purkinje potentials. That site was located along a scar border-zone. Ablation at that site resulted in the disappearance of the monomorphic ventricular premature contractions and in the complete suppression of the electrical storm. These findings appear to indicate that the area in which the Purkinje potentials were recorded along the scar border-zone played an important role in the mechanism of the polymorphic ventricular tachycardia after myocardial infarction. PMID:21720476
de la Rosa Riestra, Adriana; Rubio Caballero, José Amador; Freites Estévez, Alfonso; Alonso Belló, Javier; Botas Rodríguez, Javier
An 83-year-old male suffering from severe symptomatic aortic valve stenosis received an implant of a biological aortic prosthesis through the femoral artery without complications. Seven days after dischargement he experienced a syncope. The patient was wearing an ECG holter monitor that day, which showed a wide QRS complex tachycardia of 300 beats per minute. The electrophysiological study revealed a bundle-branch reentry ventricular tachycardia as the cause of the syncope. Radio-frequency was applied on the right-bundle branch. Twelve months later, the patient has remained asymptomatic. PMID:27134443
Li, Jin-yi; Jiang, Jing-bo; He, Yan; Luo, Jian-chun
A 59-year-old woman was referred to the institution with burdens of idiopathic ventricular tachycardia (IVT). Electroanatomic mapping revealed a complex fractionated, high frequency potential with long duration preceding the QRS onset of the IVT. The real end point of ablation was the disappearance of the conduction block of Purkinje potential during the sinus rhythm besides the disappearance of the inducible tachycardia. Location of distal catheter was at the moderator band (MB) by transthoracic echocardiography (TTE). Only irrigated radiofrequency current was delivered at both insertions of the MB which can completely eliminate the IVT. PMID:28197345
Allocca, Giuseppe; Proclemer, Alessandro; Nucifora, Gaetano; Dall'Armellina, Erica; Rebellato, Luca
A 20-year-old white judoka was admitted for severe palpitations during exercise followed by syncope. The electrocardiogram on admission revealed a wide-complex monomorphic tachycardia at a rate of 260 beats/min, with right bundle brunch block morphology and right axis deviation. Following electrical cardioversion, the electrocardiogram showed sinus rhythm with type 1 pattern of Brugada syndrome. We describe in detail the clinical course, the results of electrophysiological study, and therapeutic management. We reviewed literature data concerning a few cases of 'atypical Brugada syndrome' characterized by monomorphic ventricular tachycardia as clinical arrhythmia.
Lujan, Heidi L.; Krishnan, Sandhya
The response to myocardial ischemia is complex and involves the cardio-cardiac sympathetic reflex. Specifically, cardiac spinal (sympathetic) afferents are excited by ischemic metabolites and elicit an excitatory sympathetic reflex, which plays a major role in the genesis of ventricular arrhythmias. For example, brief myocardial ischemia leads to ATP release, which activates cardiac spinal afferents through stimulation of P2 receptors. Clinical work with patients and preclinical work with animals document that disruption of this reflex protects against ischemia-induced ventricular arrhythmias. However, the role of afferent signals in the initiation of sustained ventricular tachycardia has not been investigated. Therefore, we tested the hypothesis that cardiac spinal deafferentation reduces the susceptibility to sustained ventricular tachycardia in adult (12–15 wk of age), conscious, male Sprague-Dawley rats. To test this hypothesis, the susceptibility to ventricular tachyarrhythmias produced by occlusion of the left main coronary artery was determined in two groups of conscious rats: 1) deafferentation (bilateral excision of the T1-T5 dorsal root ganglia) and 2) control (sham deafferentation). The ventricular arrhythmia threshold (VAT) was defined as the time from coronary occlusion to sustained ventricular tachycardia resulting in a reduction in arterial pressure. Results document a significantly higher VAT in the deafferentation group (7.0 ± 0.7 min) relative to control (4.3 ± 0.3 min) rats. The decreased susceptibility to tachyarrhythmias with deafferentation was associated with a reduced cardiac metabolic demand (lower rate-pressure product and ST segment elevation) during ischemia. PMID:21677267
Rizkallah, Jacques; Kuriachan, Vikas; Brent Mitchell, L
Dronedarone is a benzofuran derivative resembling amiodarone that was intended to reduce the iodine-associated tissue deposition and organ toxicity seen with the latter. The utility of dronedarone for patients with ventricular arrhythmias has not been thoroughly evaluated. We present our experience with its use to treat refractory ventricular tachycardia storm and review the literature. An 85 year-old gentleman with multiple medical comorbidities including ischemic and non-ischemic cardiomyopathy with severe biventricular systolic dysfunction presented with ventricular tachycardia storm. Therapeutic options were limited given his frail medical status, failures of sotalol, mexilitine, and catheter ablation therapies along with drug-toxicities from amiodarone. Dronedarone was thus considered as off-label use following informed consent. The patient unfortunately developed fatal multisystem organ failure including acute severe hepatotoxicity from dronedarone. Novel therapies for drug-refractory ventricular arrhythmias are long overdue given the limitations of available pharmacologic and non-pharmacologic options. Off-label use of antiarrhythmic agents such as dronedarone is considered a treatment of last-resort in patients who otherwise have no therapeutic options. Given the paucity of reported cases regarding dronedarone for the treatment of ventricular tachyarrhythmias, no conclusive recommendations can be made at this time aside from words of caution. Despite the potential ventricular antiarrhythmic effects of dronedarone, careful patient evaluation is required to identify those at greatest risk of drug-related adverse events particularly in those patients with significant comorbidities such as advanced hepatic, renal, and cardiovascular disease.
Morin, Daniel P.; Mauer, Andreas C.; Gear, Kathleen; Zareba, Wojciech; Markowitz, Steven M.; Marcus, Frank I.; Lerman, Bruce B.
The 2 predominant etiologies of right ventricular tachycardia (VT) are arrhythmogenic right ventricular cardiomyopathy (ARVC) and idiopathic VT arising from the right ventricular outflow tract (RVOT). Both of these arrhythmias can be adrenergically mediated and may be difficult to distinguish clinically. A minor criterion for the diagnosis of ARVC is T wave inversion (TWI) in the right precordial leads during sinus rhythm. However, there have been reports of precordial TWI identified in patients with RVOT tachycardia. The purpose of this study was to determine whether patterns of precordial TWI could differentiate between the two groups. We evaluated a multicenter registry of 229 patients with VT of right ventricular origin. After appropriate exclusions (n=29), 79 patients (58% M, 40±14y) had ARVC, and 121 patients (41% M, 48±14y) had RVOT tachycardia. During sinus rhythm, 37/79 (47%) patients with ARVC and 5/121 (4%) patients with RVOT tachycardia had T-wave inversion in leads V1-V3. For the diagnosis of ARVC, TWI in leads V1-V3 had a sensitivity of 47% and a specificity of 96%. In conclusion, in patients with VT of RV origin, the presence of TWI in electrocardiogram leads V1-V3 supports the diagnosis of ARVC. PMID:20538137
South, Harry L; Osoro, Moses; Overly, Tjuan
We report a 73-year-old male with late onset monomorphic ventricular tachycardia following mitral valve repair (MVR). Typically, injury to epicardial arteries following mitral valve repair/replacement presents immediately as ventricular tachycardia/fibrillation, difficulty weaning from cardiopulmonary bypass, worsening ECG changes, increasing cardiac biomarkers, or new wall motion abnormalities. Our case illustrates a "late complication" of a distorted circumflex artery following mitral valve repair and the importance of early diagnostic angiography and percutaneous intervention.
Tung, Roderick; Josephson, Mark E; Bradfield, Jason S; Shivkumar, Kalyanam
The effects of varying the wavefront of activation on ventricular scar characterization has not been systematically assessed. Patients referred for ablation of scar-related ventricular tachycardia underwent voltage maps during a minimum of 2 wavefronts of activation. The bipolar and unipolar low-voltage areas were compared, and direct electrogram analysis was performed in regions where discrepancies were seen. Concordance between wavefronts was measured by calculating percentage of overlap between maps. Sixty endocardial voltage maps (360±147 points) were performed in 29 patients during 2 distinct wavefronts, with 3 wavefronts in 7 patients. With median bipolar and unipolar low-voltage areas of 37 and 116 cm(2), respectively, 22% and 14% variability in median scar area was observed with a different activation wavefront. Concordance between wavefronts was lower in patients with mixed scar compared to those with dense scar (52% [interquartile range, 29%-70%] versus 84% [interquartile range, 71%-87%]), with septal scars exhibiting the lowest concordance [(27% (interquartile range, 21%-56%)]. Among 16 critical sites for ventricular tachycardia, 3 (18%) were in a discordant region of scar, with one of the wavefronts showing voltage >1.5 mV. Significant differences in bipolar and unipolar low-voltage characterization of scar were observed with different ventricular activation wavefronts, particularly in septal locations and in patients without dense scar. In patients with a paucity of dense, low-voltage regions identified during substrate mapping, an alternate activation wavefront may increase the sensitivity to detect arrhythmogenic substrate and critical sites for ventricular tachycardia. © 2016 American Heart Association, Inc.
Ghanem, Mazen T.; Ahmed, Rania S.; Abd El Moteleb, Ayman M.; Zarif, John K.
During ablation of re-entrant ventricular tachycardia (VT) 3-dimensional mapping systems are now used to properly delineate the scar tissue and aid ablation of scar-related VT. The aim of our study was to outline how the mode of ablation predicts success and recurrence in large scar-related VT. When comparing patients with recurrence and patients with no recurrence, univariate analysis showed that number of ablation lesions (28 ± 8 vs. 12 ± 8, P = 0.01) and more linear ablation lesions rather than focal lesions (P = 0.03) were associated with long-term success. We demonstrated that more extensive ablation lesions and creation of linear lesions is associated with better success rate and lower recurrence rate during ablation of large scar-related ventricular tachycardia. PMID:23700377
Riera, Andrés Ricardo Pérez; Ragognete, Ricardo Gitti; Filho, Celso Ferreira; Ferreira, Marcelo; Schapachnik, Edgardo; Dubner, Sergio; Ferreira, Celso; Mochon, Agnieszka; Zhang, Li
A 32 year-old Caucasian male, an elite athlete, was admitted to the emergency department because of a sudden onset of palpitations which had lasted more than 12 hours and were associated with chest discomfort. He had a two-year history of recurrent stress-induced palpitations. He denied either episodes of syncope or any family history of sudden death. Physical examination was normal. He had no evidence of structural heart disease. The electrocardiography (ECG) documented during the event supported the diagnosis of idiopathic reentrant left ventricular tachycardia. Ventricular tachycardia ablation was successful. This case demonstrates that a careful physical examination and correct ECG diagnosis can lead to an appropriate arrhythmia management.
Mantziari, Lilian; Vassilikos, Vassilios; Anastasakis, Aris; Kotsaka, Xanthippi; Paraskevaidis, Stelios; Styliadis, Ioannis H; Luria, David
We describe the case of a 14-year-old girl with a history of syncopal episodes triggered by stress or exercise. Catecholaminergic polymorphic ventricular tachycardia was diagnosed with the aid of an implantable loop recorder. The genetic testing of the patient and her family revealed a de novo novel missense mutation (Ser4155Tyr) in the exon 90 of the ryanodine receptor gene. This mutation affects a highly conserved residue (S4155) and results to replacement of serine (S) with tyrosine (Y) leading to change in physical and chemical properties. The girl was treated with an implantable defibrillator, metoprolol and flecainide. Over 1 year of follow-up she had no recurrence of ventricular tachycardia.
Peters, Matthew N.; Khazi Syed, Rashad H.; Katz, Morgan J.; Moscona, John C.; Nijjar, Vikram S.; Bisharat, Mohannad B.
Inferior vena cava filters are commonly used to prevent pulmonary embolism in patients who manifest deep vein thrombosis and recurrent pulmonary embolism despite anticoagulation, or in patients with contraindications to anticoagulation. We report the case of a 69-year-old man with a structurally normal heart who experienced migration of an inferior vena cava filter to the right ventricle, which caused the abrupt onset of recurrent episodes of nonsustained ventricular tachycardia unresponsive to intravenous antiarrhythmic medication. Cardiac imaging revealed the location of the filter within the right ventricle, and the device was removed, with subsequent resolution of the arrhythmia. We anticipate that the incidence of inferior vena cava filter migration might increase in the future because of recent changes in device construction. The sudden appearance of nonsustained ventricular tachycardia in a patient with an inferior vena cava filter might indicate the occurrence of this potentially life-threatening sequela and should lead to emergent cardiac imaging. PMID:23914030
Durrani, Sarfraz A; Sung, Raphael; Scheinman, Melvin
Bidirectional ventricular tachycardia (BDVT) is a well-known phenomenon since it was first described in 1922. Various mechanisms have been proposed for BDVT, including digitalis toxicity, hypokalemia, Anderson-Tawil syndrome, acute myocarditis, and catecholaminergic polymorphic ventricular tachycardia. It is characterized by rapid, wide complex electrocardiogram pattern with alternating QRS morphology and axis. The alternation of the QRS is usually right bundle branch block with 180° swings in the frontal plane axis or, less commonly, alternation of right bundle branch and left bundle branch forms. Most of the proposed mechanisms involve triggered activity or enhanced automaticity. We describe a unique BDVT, with characteristics of both re-entry and triggered activity, which terminated with a focal Rf lesion.
Mandel, Jeff E; Hutchinson, Mathew D; Marchlinski, Francis E
Epicardial ablation of ventricular tachycardia (VT) presents multiple challenges for anesthetic management. General anesthesia lowers blood pressure, may interfere with arrhythmia mapping, and use of muscle relaxants precludes identification of the phrenic nerve. We describe a case in which remifentanil with minimal doses of midazolam was employed in a series of epicardial VT ablations and noninvasive programmed stimulations (NIPS), including 5 external cardioversions and discuss the advantages of this approach.
Hasdemir, Can; Musayev, Oktay; Alkan, Mustafa B; Can, Levent H; Kultursay, Hakan
A 34-year-old pregnant woman presented to the emergency department with the complaints of palpitations at 32 weeks gestation. The diagnosis of right ventricular outflow tract ventricular tachycardia (VT) was made. Intravenous 5 mg of metoprolol and 25 mg of diltiazem did not terminate the VT. Ten milligrams of adenosine were administered. Within 10 s of adenosine administration, sustained VT converted to repetitive monomorphic VT and within 30 s to normal sinus rhythm. The mother and the foetus tolerated the medications well. Non-stress test for the assessment of the foetal well-being was normal.
Bailey, James; Berkeley, Ross P
A 13-year-old girl had a witnessed loss of consciousness after a scuffle with another student at school and was found in ventricular fibrillation at the time of arrival of emergency medical services personnel. The patient was successfully defibrillated in the field and was transported to the emergency department as a presumed "traumatic arrest". The patient's initial electrocardiogram was remarkable for a prolonged QT interval, and it was discovered that multiple family members had died of cardiac events as young adults. Genetic testing subsequently revealed a mutation in the RYR2 gene, which is implicated in catecholaminergic polymorphic ventricular tachycardia.
Tokuda, Michifumi; Stevenson, William G; Nagashima, Koichi; Rubin, David A
A 38-year-old female with prior failed endocardial ablation for ventricular tachycardia (VT) was referred for further treatment. She had been diagnosed with peripartum cardiomyopathy 7 years before and had persistent left ventricular dysfunction with an ejection fraction of 20%. Epicardial voltage mapping showed extensive epicardial scar despite absence of endocardial scar. Five distinct VT morphologies were induced. Ablation was aided by electrogram characteristics, pace mapping, entrainment mapping, and establishing electrical inexcitability along areas of epicardial scar. After epicardial ablation no sustained VT was induced. She had been doing well without VT occurrence but died 1 year later unexpectedly at home.
Robert, E; Aya, A G; de la Coussaye, J E; Péray, P; Juan, J M; Brugada, J; Davy, J M; Eledjam, J J
The aim of the study was to determine whether facilitation of reentry by potassium-channel openers is related to dispersion of refractoriness and/or modification of anisotropic properties of ventricular myocardium. The dispersion of ventricular effective refractory period (VERP), longitudinal and transverse ventricular conduction velocities (thetaL and thetaT, respectively), and wavelength [lambda = VERP x theta(L or T)] were studied in Langendorff-perfused left ventricular epicardium in 20 rabbits during infusion of incremental doses of levcromakalim or nicorandil. Dispersion of refractoriness was assessed using standard deviation of VERP mean (SD-VERP), dispersion index (DI; SD-VERP/mean VERP), and maximum dispersion (Dmax = VERPmax - VERPmin). Ventricular conduction velocities and anisotropic ratio were not modified, whatever the dose used. VERP and lambda were significantly shortened at high concentrations of levcromakalim and nicorandil. At these doses, SD-VERP, DI, and Dmax were increased significantly. Analysis of ventricular tachycardia induction, performed using a high-resolution ventricular mapping system, confirmed that heterogeneity and shortening of VERP were factors inducing functional conduction block. Our data suggest that, in rabbit left ventricular epicardium, functional conduction block facilitating the occurrence of reentry could be initiated by shortening and, especially, by dispersion of refractoriness during infusion of potassium-channel openers.
Fishberger, Steven B; Olen, Melissa M; Rollinson, Nancy L; Rossi, Anthony F
Catheter ablation of idiopathic left ventricular tachycardia in the pediatric population remains challenging. A recent multicenter study reported limited success with 14% not undergoing ablation due to inability to induce ventricular tachycardia (VT) or blood pressure instability during tachycardia. Creating complete or partial fascicular block with radiofrequency catheter ablation is a technique that may eliminate VT. This approach is performed during sinus rhythm, enabling atrioventricular conduction monitoring and maintaining stable hemodynamics. Importantly, induction of VT is not necessary for mapping or assessing efficacy of the procedure. A retrospective review of pediatric patients (3-17 years) with recurrent, documented idiopathic left ventricular tachycardia by electrocardiogram who received catheter ablation by creating fascicular block as a therapeutic endpoint was performed. All had ablation at the site of an identified Purkinje potential. There were six patients with idiopathic left ventricular tachycardia, five originating from the posterior fascicle and one from the anterior fascicle. VT was not induced or spontaneous in four patients using programmed stimulation and isoproterenol infusion. All patients had a QRS axis shift following ablation, though none met criteria for fascicular block. At follow up (7-49 months, mean 27 months), all patients had persistence of this shift. There were no recurrences of VT and none of the patients were taking antiarrhythmic medication. The technique of creating partial fascicular block appears to be a safe and effective approach to ablation of idiopathic left ventricular tachycardia in children. © 2014 Wiley Periodicals, Inc.
Liu, Qiang; Shehata, Michael; Jiang, Ruhong; Yu, Lu; Chen, Shiquan; Zhu, Jun; Ehdaie, Ashkan; Sovari, Ali A; Cingolani, Eugenio; Chugh, Sumeet S; Jiang, Chenyang; Wang, Xunzhang
The underlying mechanisms of reentry during left posterior fascicular ventricular tachycardia (LPF-VT) remain unclear. The purpose of this study is to describe the components of LPF-VT reentry circuit and their electrophysiological properties. Fourteen consecutive patients with LPF-VT underwent electrophysiology study and radiofrequency ablation. Via a multipolar electrode catheter placed from a retrograde aortic approach, a sharp inflection, high-frequency potential (P1) was detected in 9 patients (64%). The ranges of length and velocity of recorded P1 were 9 to 30 mm and 0.5 to 1.2 mm/ms, respectively. Macroreentry involving the ventricular myocardium was confirmed to be the mechanism in all patients by premature ventricular stimuli delivery or entrainment of LPF-VT with progressive fusion, or both. During LPF-VT, the earliest left posterior fascicle (LPF, P2) was considered to be the site of connection between P1 and P2, and the site of the earliest P2 along the left posterior ventricular septum correlated well with the His-ventricular interval during tachycardia. Radiofrequency ablation focused on the P1 potentials (9 patients with a recorded P1) or earliest P2 (5 patients without a recorded P1) was successful in all 14 patients. After 4.5±3.0 months of follow-up, no patients had recurrence of LPF-VT. The LPF-VT macroreentrant loop involves the ventricular myocardium, a part of the LPF, a slow conduction zone, and in certain cases, a specially conducting P1 fiber. The His-ventricular interval during LPF-VT correlates with multiple electrophysiological measures and is a useful marker for identification of the optimal ablation site. © 2016 American Heart Association, Inc.
Hammond, Drayton A; Thano, Estela; Bohnenberger, Kristin A; McAllister, Matthew W; Wannenburg, Thomas; Hsu, Steve; Gurley, Bill J; Kim, Robert
Dietary supplements have a long history of causing adverse effects. Ventricular arrhythmias have not been described with Hydroxycut Gummies. To report a case of ventricular arrhythmia after prolonged use of a popular dietary supplement, Hydroxycut Gummies. An 18-year-old female with no significant past medical history presented with life-threatening ventricular arrhythmia following about 10 days of use of Hydroxycut Gummies, a legal dietary supplement previously unreported to cause this complication. The patient received external cardioversion due to progressive decline in mental status and persistent hypotension and was initiated on intravenous procainamide at an outside hospital. Left ventricular ejection fraction was 45% to 50%, and cardiac MRI showed no definite finding of infarct, myocarditis, or fibrosis. Beta-blocker therapy was initiated, and there was a progressive reduction in ventricular arrhythmia burden with an improvement of symptoms over the next few days. Two and a half months after the initial hospitalization, follow-up Holter monitor revealed occasional accelerated idioventricular rhythm events and a significant reduction in, but still occasional, long monomorphic ventricular tachycardia events. None of the ingredients listed in this product have been associated with cardiac dysrhythmias in the literature. One phytochemical potentially in the product is alpha-quinidine, which could be the cause of the adverse event. However, there was no other identifiable etiology for the ventricular tachycardia, which resolved after the discontinuation of supplement and the addition of beta-blocker therapy. Hydroxycut Gummies should be considered a probable cause of this patient's arrhythmia given the lack of another etiology and a Naranjo Scale score of 6.
Thano, Estela; Bohnenberger, Kristin A.; McAllister, Matthew W.; Wannenburg, Thomas; Hsu, Steve; Gurley, Bill J.; Kim, Robert
Background: Dietary supplements have a long history of causing adverse effects. Ventricular arrhythmias have not been described with Hydroxycut Gummies. Objective: To report a case of ventricular arrhythmia after prolonged use of a popular dietary supplement, Hydroxycut Gummies. Case Report: An 18-year-old female with no significant past medical history presented with life-threatening ventricular arrhythmia following about 10 days of use of Hydroxycut Gummies, a legal dietary supplement previously unreported to cause this complication. The patient received external cardioversion due to progressive decline in mental status and persistent hypotension and was initiated on intravenous procainamide at an outside hospital. Left ventricular ejection fraction was 45% to 50%, and cardiac MRI showed no definite finding of infarct, myocarditis, or fibrosis. Beta-blocker therapy was initiated, and there was a progressive reduction in ventricular arrhythmia burden with an improvement of symptoms over the next few days. Two and a half months after the initial hospitalization, follow-up Holter monitor revealed occasional accelerated idioventricular rhythm events and a significant reduction in, but still occasional, long monomorphic ventricular tachycardia events. None of the ingredients listed in this product have been associated with cardiac dysrhythmias in the literature. One phytochemical potentially in the product is alpha-quinidine, which could be the cause of the adverse event. However, there was no other identifiable etiology for the ventricular tachycardia, which resolved after the discontinuation of supplement and the addition of beta-blocker therapy. Conclusion: Hydroxycut Gummies should be considered a probable cause of this patient’s arrhythmia given the lack of another etiology and a Naranjo Scale score of 6. PMID:26448674
Lerma, Claudia; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen; Glass, Leon
The objective was to determine the characteristics of heart rate variability and ventricular arrhythmias prior to the onset of ventricular tachycardia (VT) in patients with an implantable cardioverter defibrillator (ICD). Sixty-eight beat-to-beat time series from 13 patients with an ICD were analyzed to quantify heart rate variability and ventricular arrhythmias. The episodes of VT were classified in one of two groups depending on whether the sinus rate in the 1 min preceding the VT was greater or less than 90 beats per minute. In a subset of patients, increased heart rate and reduced heart rate variability was often observed up to 20 min prior to the VT. There was a non-significant trend to higher incidence of premature ventricular complexes (PVCs) before VT compared to control recordings. The patterns of the ventricular arrhythmias were highly heterogeneous among different patients and even within the same patient. Analysis of the changes of heart rate and heart rate variability may have predictive value about the onset of VT in selected patients. The patterns of ventricular arrhythmia could not be used to predict onset of VT in this group of patients.
Betensky, B P; Marchlinski, F E
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.
Morishima, Itsuro; Nogami, Akihiko; Tsuboi, Hideyuki; Sone, Takahito
Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the sinus beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.
Brugada, Josep; Berruezo, Antonio; Cuesta, Alejandro; Osca, Joaquin; Chueca, Enrique; Fosch, Xavier; Wayar, Luis; Mont, Lluis
The purpose of this study was to analyze the feasibility, efficacy, and safety of epicardial radiofrequency (RF) ablation in patients with incessant ventricular tachycardia (VT). Management of patients with incessant VT is a difficult clinical problem. Drugs and RF catheter ablation are not always effective. A nonsurgical transthoracic epicardial RF ablation can be an alternative in patients refractory to conventional therapy. Epicardial RF ablation was performed in 10 patients who presented with incessant VT despite the use of two or more intravenous antiarrhythmic drugs. In eight patients, endocardial ablation (EdA) failed to control the tachycardia. In the remaining two patients, epicardial ablation (EpA) was first attempted because of left ventricular thrombus and severe artery disease, respectively. Eight patients had a diagnosis of coronary artery disease with healed myocardial infarction. One patient had dilated cardiomyopathy, and one patient had idiopathic, incessant VT. In patients with structural heart disease, the mean ejection fraction was 0.28 +/- 0.10%. Four patients previously received an implantable defibrillator. The EpA effectively terminated the incessant tachycardia in eight patients, which represents a success rate of 80%. In them, after a follow-up of 18 +/- 18 months, a single episode of a different VT was documented in one patient. No significant complications occurred related to the procedure. In patients with incessant VT despite the use of drugs or standard EdA, the epicardial approach was very effective and should be considered as an alternative in this life-threatening situation.
Frustaci, Andrea; Petrosillo, Nicola; Ippolito, Giuseppe; Chimenti, Cristina
To describe the influence of cardiac conduction tissue infection by Influenza A virus. A 54-year-old man with non-sustained ventricular tachycardia underwent noninvasive and invasive cardiac studies including left ventricular endomyocardial biopsy (LVEMB). Non-invasive studies showed normal cardiac parameters with no signal abnormalities. LVEMB revealed an influenza virus focal myocarditis with inflammatory infiltration of conduction tissue. Non-invasive studies showed normal cardiac parameters with preserved bi-ventricular function. CMR failed to show signal abnormalities including edema and areas of late-gadolinium enhancement. Endomyocardial biopsy (EMB) revealed an influenza virus focal lymphocytic myocarditis. Biopsy samples included sections of conduction tissue with inflammatory infiltration and cell necrosis. Therapy with oseltamivir was followed by disappearance of electrical instability at ECG and Holter monitoring. Acute myocarditis in its arrhythmic phenotype is probably characterized by a significant inflammation of conduction tissue. Antiviral agents have an actually underestimated and potentially more contributive therapeutic role.
Kim, Ju Youn; Shin, Woo-Seung; Kim, Tae-Seok; Kim, Sung-Hwan; Kim, Ji-Hoon; Jang, Sung-Won; Pak, Hui-Nam; Nam, Gi-Byoung; Lee, Man Young; Rho, Tai-Ho
Background and Objectives Identifying the critical isthmus of slow conduction is crucial for successful treatment of scar-related ventricular tachycardia. Current 3D mapping is not designed for tracking the critical isthmus and may lead to a risk of extensive ablation. We edited the algorithm to track the delayed potential in order to visualize the isthmus and compared the edited map with a conventional map. Subjects and Methods We marked every point that showed delayed potential with blue color. After substrate mapping, we edited to reset the annotation from true ventricular potential to delayed potential and then changed the window of interest from the conventional zone (early, 50-60%; late, 40-50% from peak of QRS) to the edited zone (early, 80-90%; late, 10-20%) for every blue point. Finally, we compared the propagation maps before and after editing. Results We analyzed five scar-related ventricular tachycardia cases. In the propagation maps, the resetting map showed the critical isthmus and entrance and exit sites of tachycardia that showed figure 8 reentry. However, conventional maps only showed the earliest ventricular activation sites and searched for focal tachycardia. All of the tachycardia cases were terminated by ablating the area around the isthmus. Conclusion Identifying the channel and direction of the critical isthmus by a new editing method to track delayed potential is essential in scar-related tachycardia. PMID:26798386
Ware, David L.; Yang, Chunjie; Gowda, Ashok; Bell, Brent A.; Boor, Paul; Motamedi, Massoud
Ventricular tachycardia (VT) is a rapid and life-threatening cardiac arrhythmia that most often occurs after healing of myocardial infarction. The same catheter techniques that use resistive endocardial heating to treat supraventricular tachycardias are less effective against post-infarction VT, in part because cure of the latter arrhythmia requires large volume, deep tissue coagulation. Greater risk may also be incurred when standard percutaneous methods are used to induce deep tissue heating, because excess endocardial damage can cause mural thrombi, and a large area of non-lethal endocardial injury may itself generate VT. To address these problems we have developed a unique optical fiber for direct intramyocardial photocoagulation which, when coupled to a diode laser (805 nm), can generate lesions up to 1 cm deep and wide without disruption of the endocardium. With further refinement this system may effectively and safely cure post- infarction VT.
Proietti, Riccardo; Roux, Jean-François; Essebag, Vidal
Ablation of ventricular tachycardia in structural heart disease has evolved to include techniques to ablate the myocardial substrate in sinus rhythm for ventricular tachycardias that are noninducible or hemodynamically unstable. The intricacies of the complex functional and fixed components of the myocardial scar involved in the arrhythmic mechanisms require careful consideration in identifying targets for substrate ablation identified in sinus rhythm. The substrate ablation approach referred to as 'scar homogenization' aims to thoroughly abolish any abnormal electrical activity inside the scar. However, this extensive approach may target bystander abnormal activity that is not necessarily related to arrhythmias. Recently, different substrate ablation strategies have been developed to more selectively target areas of the scar responsible for ventricular tachycardia. New technologies have also been introduced to provide offline analysis of the electroanatomical substrate, and to improve high-density mapping of the myocardial scar. Recent advances have improved the ability to ablate ventricular tachycardia using techniques that allow targeting the responsible myocardial substrate while in sinus rhythm. Further research using higher-density mapping with more sophisticated online and offline analysis will aid in the assessment of the complex arrhythmogenicity of the scar and improve efficacy of ventricular tachycardia ablation.
Roston, Thomas M; Cunningham, Taylor C; Sanatani, Shubhayan
Since the sentinel description of exercise-triggered ventricular arrhythmias in 21 children, our recognition and understanding of catecholaminergic polymorphic ventricular tachycardia has improved substantially. A variety of treatments are now available, but reaching a diagnosis before cardiac arrest remains a challenge. Most cases are related to variants in the gene encoding for ryanodine receptor-2 (RyR2), which mediates calcium-induced calcium release. Up to half of cases remain genetically elusive. The condition is presently incurable, but one basic intervention, the universal administration of β-blockers, has improved survival. In the past, implantable cardioverter-defibrillators (ICDs) were frequently implanted, especially in those with a history of cardiac arrest. Treatment limitations include under-dosing and poor compliance with β-blockers, and potentially lethal ICD-related electrical storm. Newer therapies include flecainide and sympathetic ganglionectomy. Limited data have suggested that genotype may predict phenotype in catecholaminergic polymorphic ventricular tachycardia, including a higher risk of life-threatening cardiac events in subjects with variants in the C-terminus of ryanodine receptor-2 (RyR2). At present, international efforts are underway to better understand this condition through large prospective registries. The recent publication of gene therapy in an animal model of the recessive form of the disease highlights the importance of improving our understanding of the genetic underpinnings of the disease.
Murata, Hiroshige; Miyauchi, Yasushi; Hayashi, Meiso; Iwasaki, Yu-Ki; Yodogawa, Kenji; Ueno, Akira; Hayashi, Hiroshi; Tsuboi, Ippei; Uetake, Shunsuke; Takahashi, Kenta; Yamamoto, Teppei; Maruyama, Mitsunori; Akutsu, Koichi; Yamamoto, Takeshi; Kobayashi, Yoshinori; Tanaka, Keiji; Atarashi, Hirotsugu; Katoh, Takao; Shimizu, Wataru
Few reports are available on the characteristics of electrical storms of ventricular tachycardia (VT storm) refractory to intravenous (IV) amiodarone. IV-amiodarone was administered to 60 patients with ventricular tachyarrhythmia between 2007 and 2012. VT storms, defined as 3 or more episodes of VT within 24 h, occurred in 30 patients (68±12 years, 7 female), with 12 having ischemic and 18 non-ischemic heart disease. We compared the clinical and electrocardiographic characteristics of the patients with VT storms suppressed by IV-amiodarone (Effective group) to those of patients not affected by the treatment (Refractory group). IV-amiodarone could not control recurrence of VT in 9 patients (30%). The Refractory group comprised 5 patients with acute myocardial infarctions. Although there was no difference in the VT cycle length, the QRS duration of both the VT and premature ventricular contractions (PVCs) followed by VT was narrower in the Refractory group than in the Effective group (140±30 vs. 178±25 ms, P<0.01; 121±14 vs. 179±22 ms, P<0.01). In the Refractory group, additional administration of IV-mexiletine and/or Purkinje potential-guided catheter ablation was effective. IV-amiodarone-refractory VT exhibited a relatively narrow QRS tachycardia. The narrow triggering PVCs, suggesting a Purkinje fiber origin, may be treated by additional IV-mexiletine and endocardial catheter ablation.
Alvarez, Paulino; Schurmann, Paul; Smith, Melanie; Valderrábano, Miguel; Lin, C. Huie
We report a case of a 51-year-old male who developed frequent nonsustained episodes of monomorphic ventricular tachycardia after being diagnosed with bioprosthetic aortic valve endocarditis and treated with intravenous antibiotics. A peripherally inserted central venous catheter (PICC) had been placed without complication less than 24 hours prior to the episodes. Ventricular tachycardia (VT) occurred during the night, while sleeping, when he assumed a right lateral decubitus position with abduction of the right arm and placement of the forearm under his head. VT occurred repeatedly when such position was assumed again upon request, and it would terminate immediately when sitting upright. The PICC was repositioned in the superior vena cava without further VT. He was discharged home the same day and underwent successful aortic valve replacement 2 months later. Position-dependent VT related to PICC requires careful history taking and PICC repositioning to make the diagnosis. X-ray in different patient positions during PICC placement can be considered to evaluate for ventricular migration. PMID:27826374
Glikson, Michael; Swerdlow, Charles D; Gurevitz, Osnat T; Daoud, Emile; Shivkumar, Kalyanam; Wilkoff, Bruce; Shipman, Tamara; Friedman, Paul A
Discriminators for ventricular/supraventricular tachycardia. Dual-chamber implantable cardioverter defibrillators (ICDs) use discriminators to differentiate between supraventricular tachycardias (SVTs) and ventricular tachycardias (VT), the accuracy of which may depend on the type and method used. ICDs can combine rate branching of tachyarrhythmias according to their A:V relationship with two SVT-VT discriminators in each rate branch, using ANY (either) or ALL (both) logic. Our goal was to determine the optimal discriminator combination. Stored electrogram data from 596 spontaneous tachyarrhythmias from 203 patients with Photon DR ICDs were analyzed. Arrhythmias are first classified by the relationship of atrial and ventricular rates (rate branches VA) followed by additional discriminators: morphology and/or sudden onset if V=A; morphology and/or interval stability if V
Faggioni, Michela; Hwang, Hyun Seok; van der Werf, Christian; Nederend, Ineke; Kannankeril, Prince J.; Wilde, Arthur A.M.; Knollmann, Björn C.
Rationale Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is caused by mutations in cardiac ryanodine receptor (RyR2) or calsequestrin (Casq2) genes. Sinoatrial node dysfunction associated with CPVT may increase the risk for ventricular arrhythmia. Objective To test the hypothesis that CPVT is suppressed by supraventricular overdrive stimulation. Methods and Results Using CPVT mouse models (Casq2−/− and RyR2R4496C+/− mice), the effect of increasing sinus heart rate was tested by pretreatment with atropine and by atrial overdrive pacing. Increasing intrinsic sinus rate with atropine before catecholamine challenge suppressed ventricular tachycardia (VT) in 86% of Casq2−/− mice (6/7) and significantly reduced the ventricular arrhythmia (VA) score (atropine: 0.6±0.2 vs. vehicle: 1.7±0.3, p<0.05). Atrial overdrive pacing completely prevented VA in 16/19 (84%) Casq2−/− and in 7/8 (88%) RyR2R4496C+/− mice and significantly reduced ventricular premature beats in both CPVT models (p<0.05). Rapid pacing also prevented spontaneous calcium waves and triggered beats in isolated CPVT myocytes. In humans, heart-rate dependence of CPVT was evaluated by screening a CPVT patient registry for antiarrhythmic drug-naïve individuals that reached >85% of their maximum predicted heart rate during exercise testing. All 18 CPVT patients who fulfilled the inclusion criteria exhibited VA before reaching 87% of maximum heart rate. In six CPVT patients (33%), VA were paradoxically suppressed as sinus heart rates increased further with continued exercise. Conclusions Accelerated supraventricular rates suppress VAs in two CPVT mouse models and in a subset of CPVT patients. Hypothetically, atrial overdrive pacing may be a therapy for preventing exercise-induced VT in treatment-refractory CPVT patients. PMID:23295832
Okajima, Katsunori; Kiuchi, Kunihiko; Yokoi, Kiminobu; Teranishi, Jin; Aoki, Kosuke; Shimane, Akira; Nakamura, Yoshihide; Kimura, Motoko; Horikawa, Yoshio; Yoshida, Masato; Maniwa, Yoshimasa
A 27-year-old woman with frequent implantable cardioverter defibrillator (ICD) shocks related to catecholaminergic polymorphic ventricular tachycardia (VT) experienced aborted sudden death due to incessant polymorphic VT despite the administration of beta-blockers, verapamil, and flecainide. Catheter ablation failed to suppress the polymorphic VT. Based on the temporary efficacy of the local anesthetic administered at the left and right cervical sympathetic nerves to suppress VT under an isoproterenol infusion, stepwise, bilateral thoracoscopic sympathectomy was performed. Postoperatively, no further VT or syncopal episodes were documented under ICD telemetry. Bilateral thoracoscopic sympathectomy may be an alternative for patients with drug-refractory catecholaminergic polymorphic VT. PMID:26949433
Sadek, Mouhannad M; Schaller, Robert D; Supple, Gregory E; Frankel, David S; Riley, Michael P; Hutchinson, Mathew D; Garcia, Fermin C; Lin, David; Dixit, Sanjay; Zado, Erica S; Callans, David J; Marchlinski, Francis E
Scar-related reentry is the most common mechanism of monomorphic ventricular tachycardia (VT) in patients with structural heart disease. Catheter ablation has assumed an increasingly important role in the management of VT in this setting, and has been shown to reduce VT recurrence and implantable cardioverter defibrillator (ICD) shocks. The approach to mapping and ablation will depend on the underlying heart disease etiology, VT inducibility and haemodynamic stability. This review explores pre-procedural planning, approach to ablation of both mappable and unmappable VT, and post-procedural testing. Future developments in techniques and technology that may improve outcomes are discussed. PMID:26835085
Ponti, Roberto De
In patients with structural heart disease, ventricular tachycardia (VT) worsens the clinical condition and may severely affect the short- and long-term prognosis. Several therapeutic options can be considered for the management of this arrhythmia. Among others, catheter ablation, a closed-chest therapy, can prevent arrhythmia recurrences by abolishing the arrhythmogenic substrate. Over the last two decades, different techniques have been developed for an effective approach to both tolerated and untolerated VTs. The clinical outcome of patients undergoing ablation has been evaluated in multiple studies. This editorial gives an overview of the role, methodology, clinical outcome and innovative approaches in catheter ablation of VT. PMID:22125669
Sharma, Tarun; Sharma, Aradhna; Bhatnagar, Mukul
Sustained ventricular tachycardia (VT) is a life-threatening condition which requires immediate intervention. We report a case of unusual etiology of sustained VT in a 42-year-old male after a wasp bite in the absence of anaphylaxis. The patient was treated with amiodarone and improved within 48 h. Thus, wasp stings can lead to serious tachyarrhythmias which can be life-threatening. Emergency care physicians should be aware of such arrhythmias in the setting of wasp bites which can be fatal. PMID:28349013
Sehar, Nandini; Mears, Jennifer; Bisco, Susan; Patel, Sandeep; Lachman, Nirusha; Asirvatham, Samuel J
After initial documentation of excellent efficacy with radiofrequency ablation, this procedure is being performed increasingly in more complex situations and for more difficult arrhythmia. In these circumstances, an accurate knowledge of the anatomic basis for the ablation procedure will help maintain this efficacy and improve safety. In this review, we discuss the relevant anatomy for electrophysiology interventions for typical right atrial flutter, atrial fibrillation, and outflow tract ventricular tachycardia. In the pediatric population, maintaining safety is a greater challenge, and here again, knowing the neighboring and regional anatomy of the arrhythmogenic substrate for these arrhythmias may go a long way in preventing complications. PMID:20811537
Nirei, Kazushige; Nakamura, Hitomi; Matsuoka, Shunichi; Yamana, Yoichiro; Yoda, Shunichi; Hirayama, Atsushi; Moriyama, Mitsuhiko
We experienced two patients with serious arrhythmias associated with the administration of ledipasvir (LDV) and sofosbuvir (SOF). Neither patient took amiodarone, an agent for which concomitant use is prohibited. One patient was 82 years old and hypertensive; the other was 72 years old and had no cardiovascular risk factors such as hypertension or diabetes mellitus. The arrhythmias were both serious ventricular tachycardia (VT) that converted spontaneously to sinus rhythm, without treatment, and both patients had good outcomes. These cases suggest that LDV/SOF may be associated with an increased risk of heart-related events. PMID:28381744
Nirei, Kazushige; Nakamura, Hitomi; Matsuoka, Shunichi; Yamana, Yoichiro; Yoda, Shunichi; Hirayama, Atsushi; Moriyama, Mitsuhiko
We experienced two patients with serious arrhythmias associated with the administration of ledipasvir (LDV) and sofosbuvir (SOF). Neither patient took amiodarone, an agent for which concomitant use is prohibited. One patient was 82 years old and hypertensive; the other was 72 years old and had no cardiovascular risk factors such as hypertension or diabetes mellitus. The arrhythmias were both serious ventricular tachycardia (VT) that converted spontaneously to sinus rhythm, without treatment, and both patients had good outcomes. These cases suggest that LDV/SOF may be associated with an increased risk of heart-related events.
Ergul, Yakup; Ozyilmaz, Isa; Bilici, Meki; Ozturk, Erkut; Haydin, Sertaç; Guzeltas, Alper
An implantable cardioverter defibrillator (ICD) storm involves very frequent arrhythmia episodes and ICD shocks, and it is associated with poor short-term and long-term prognosis. Radiofrequency catheter ablation can be used as an effective rescue treatment for patients with an ICD storm. To our knowledge, this is the first report of an infant with hypertrophic cardiomyopathy presenting with an ICD storm and undergoing successful radiofrequency catheter ablation salvage treatment for the fast left posterior fascicular ventricular tachycardia. © 2017 Wiley Periodicals, Inc.
Orr, Timothy M.; Orr, Daniel L.
A 4-year-old 16-kg boy presented for full mouth dental rehabilitation in a private pediatric dental office. The patient had no significant previous medical history. Upon sevoflurane induction by a dentist anesthesiologist, the patient converted from normal sinus rhythm to pulseless ventricular tachycardia. Advanced cardiac life support protocol was initiated. After 2 automatic external defibrillator shocks were delivered in conjunction with epinephrine administration, the patient returned to normal sinus rhythm. The patient was transported via emergency medical service paramedics to a local children's hospital emergency room where he was observed uneventfully for 24 hours prior to discharge. PMID:26650495
Hiremath, Gurumurthy; Li, Walter; Foltz, Rhonda; Roy-Burman, Arup; Cocalis, Mark; Tanel, Ronn E
Idiopathic left ventricular tachycardia of the Belhassen type is rare in infants. We present a 6-month-old infant girl with a wide-complex tachycardia with right bundle branch block QRS morphology, a superior axis, and atrioventricular dissociation, consistent with a left anterior fascicular tachycardia. Initial echocardiogram revealed depressed ventricular function. The tachycardia was unresponsive to therapeutic trials of adenosine, esmolol, procainamide, and lidocaine. There was brief conversion of the tachycardia to sinus rhythm with transesophageal atrial overdrive pacing, suggesting a reentrant mechanism of the arrhythmia. Ultimately, the judicious administration of intravenous verapamil resulted in termination of the arrhythmia, which has been sustained on oral therapy.
Olufunke Adewumi, Abimbola; Grace Tucker, Laura
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a type of cardiac arrhythmia that occurs in people with a structurally normal heart. Stress or anxiety-induced release of endogenous catecholamines causes a dysfunction in the myocytic calcium-ion channel, leading to ventricular arrhythmias that can cause dizziness, syncope, or sudden cardiac death. Since dental procedures can be anxiety-provoking, the main purpose of this paper is to report the dental management of a young patient with dental fear and CPVT. Several other issues are also discussed, such as the importance of continual collaboration with medical colleagues, the risk-benefit of using epinephrine-containing local anesthesia for dental treatment for patients with arrythmias, the potential risk of repeated general anesthesia in a patient with a cardiac arrhythmia, and the challenges of providing comprehensive dental treatment in a high caries-risk patient with extreme dental anxiety.
Berte, Benjamin; Yamashita, Seigo; Sacher, Frederic; Cochet, Hubert; Hooks, Darren; Aljefairi, Nora; Amraoui, Sana; Denis, Arnaud; Derval, Nicolas; Hocini, Meleze; Haïssaguerre, Michel; Jaïs, Pierre
Ventricular tachycardia (VT) ablation for ventricular arrhythmias is a validated approach, typically performed endocardially, or combined with an epicardial approach if endocardial ablation failed or in case of non-ischaemic cardiomyopathy. We report our experience with epicardial only procedure in a subset of patients with incessant VT or VT storm. This was a single centre retrospective study. Between 2011 and 2014, all patients referred for VT ablation were reviewed at CHU Bordeaux. All patients with an epicardial only (anterior percutaneous approach) mapping and ablation procedure were included. In total, 296 patients underwent a VT ablation and 4 (all male, 70 ± 7 years, 27 ± 11% left ventricular ejection fraction) of them underwent an epicardial only procedure: two ischaemic patients had an endocardial left ventricular thrombus and incessant VT. One patient post-myocarditis had a failed a previous endocardial procedure without local abnormal ventricular activity (LAVA). The fourth patient had a dilated cardiomyopathy and a complicated epicardial puncture followed by mild continuous bleeding (200 mL) precluding anticoagulation associated with left ventricular endocardial access. Local abnormal ventricular activity elimination was verified only epicardially in all and obtained in two patients and non-inducibility was tested and achieved in the two patients without thrombus. No further complications occurred. After a mean follow-up of 21 ± 12 months, one patient (25%) had recurrence of VT and no patient death was observed. Epicardial only ablation seems feasible and effective and useful in a limited subset of patients with incessant VT. However, endpoints are more difficult to evaluate and long-term follow-up is needed. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: email@example.com.
Öztürk, Semi; Aktemur, Tuğba; Kalyoncuoğlu, Muhsin; Durmuş, Gündüz; Can, Mehmet
A 52-year-old man complaining of persistent recurring chest pain at night underwent coronary angiogram at another institution. Normal coronaries were observed and he was discharged with muscle spasmolytic prescription. Since symptoms had continued, 24-hour Holter monitoring was ordered at our facility and results revealed huge ST elevation and polymorphic ventricular tachycardia. Cold pressor test performed in catheterization laboratory also resulted in ventricular tachycardia. Nifedipine was prescribed and follow-up Holter monitoring revealed no further vasospastic episodes. Utility of 24-hour Holter rhythm monitoring and cold pressor test in patients with recurrent chest pain at night is demonstrated in this report.
Schilling, R; Peters, N; Davies, D
OBJECTIVE—Treatment of ventricular tachycardia (VT) in coronary heart disease has to date been limited to palliative treatment with drugs or implantable defibrillators. The results of curative treatment with catheter ablation have proved disappointing because the complexity of the VT mechanism makes identification of the substrate using conventional mapping techniques difficult. The use of a mapping technology that may address some of these issues, and thus make possible a cure for VT with catheter ablation, is reported. PATIENTS AND INTERVENTION—The non-contact system, consisting of a multielectrode array catheter (MEA) and a computer mapping system, was used to map VT in 24 patients. Twenty two patients had structural heart disease, the remainder having "normal" left ventricles with either fasicular tachycardia or left ventricular ectopic tachycardia. RESULTS—Exit sites were demonstrated in 80 of 81 VT morphologies by the non-contact system, and complete VT circuits were traced in 17. In another 37 morphologies of VT 36 (30)% (mean (SD)) of the diastolic interval was identified. Thirty eight VT morphologies were ablated using 154 radiofrequency energy applications. Successful ablation was achieved by 77% of radiofrequency within diastolic activation identified by the non-contact system and was significantly more likely to ablate VT than radiofrequency at the VT exit, or remote from diastolic activation. Over a mean follow up of 1.5 years, 14 patients have had no recurrence of VT and only two target VTs have recurred. Five patients have had recurrence of either slower non-sustained, undocumented or fast non-target VT. Five patients have died, one from tamponade from a pre-existing temporary pacing wire, and four from causes unrelated to the procedure. CONCLUSION—The non-contact system can safely be used to map and ablate haemodynamically stable VT with low VT recurrence rates. It is yet to be established whether this system may be applied
Ozyilmaz, Isa; Ozyilmaz, Sinem; Ergul, Yakup; Akdeniz, Celal; Tuzcu, Volkan
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an electrophysiological disorder of a physically normal heart that occurs in children when the body is subjected to intense emotional or physical stress that causes adrenergic discharge. This troubling disease can be sporadic (spontaneous) or familial (genetic/inherited). Unfortunately, its associated ventricular tachycardia may cause sudden death, so early diagnosis of CPVT is very important. Treatment modalities include medical treatment, implantation of a cardioverter defibrillator, or surgical sympatectomy; but the implantable cardioverter defibrillator (ICD) should be the first choice in patients with a history of cardiac arrest. We herein present the case of a patient diagnosed with CPVT after a successful cardiopulmonary resuscitation triggered by blunt chest trauma. We implanted an implantable cardioverter defibrillator and started oral B-blocker treatment. During the course of follow-up, flecainide was added to his treatment depending on the patient’s status regarding recurrent ICD shock. The patient has now continued follow-up without recurrent ICD shock since flecainide treatment was initiated. In conclusion, in patients with syncope and sudden cardiac arrest secondary to physical stress or blunt chest trauma, CPVT should be considered and an implantable cardioverter defibrillator must be implanted. Additionally, flecainide theraphy should be considered to decrease recurrent ICD shock. PMID:27122894
Hwang, Gyo-Seung; Park, Jin-Sun; Yang, Hyoung-Mo; Lim, Hong-Seok; Choi, Byoung-Joo; Choi, So-Yeon; Yoon, Myeong-Ho; Shin, Joon-Han; Tahk, Seung-Jea
An early repolarization (ER) pattern on electrocardiogram (ECG) sometimes has the risk of polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF). An abnormal ER pattern can develop in various experimental or clinical situations. We experienced 4 cases of abnormal ER pattern with or without PVT during the radiofrequency (RF) ablation of the left accessory pathway. An electrophysiologic study and RF ablation were performed in 4 patients. Four patients had atrioventricular reentrant tachycardia. During RF ablation of the left accessory pathway, severe chest pain developed and was followed by abnormal J-point elevation. During the ongoing chest pain and J-point elevation, coronary angiograms showed normal findings. The chest pain and J-point elevation were followed by PVT or VF that was unresponsive to defibrillation. The PVT was spontaneously terminated and repeated. After 0.5 mg atropin was given, chest pain and ECG change disappeared. The mechanisms of ER syndrome during RF ablation might be increased vagal tone due to chest pain or direct vagal stimulation. © 2013 Wiley Periodicals, Inc.
Santangeli, Pasquale; Zado, Erica S; Supple, Gregory E; Haqqani, Haris M; Garcia, Fermin C; Tschabrunn, Cory M; Callans, David J; Lin, David; Dixit, Sanjay; Hutchinson, Mathew D; Riley, Michael P; Marchlinski, Francis E
Catheter ablation of ventricular tachycardia (VT) in arrhythmogenic right ventricular cardiomyopathy improves short-term VT-free survival. We sought to determine the long-term outcomes of VT control and need for antiarrhythmic drug therapy after endocardial (ENDO) and adjuvant epicardial (EPI) substrate modification in patients with arrhythmogenic right ventricular cardiomyopathy. We examined 62 consecutive patients with Task Force criteria for arrhythmogenic right ventricular cardiomyopathy referred for VT ablation with a minimum follow-up of 1 year. Catheter ablation was guided by activation/entrainment mapping for tolerated VT and pacemapping/targeting of abnormal substrate for unmappable VT. Adjuvant EPI ablation was performed when recurrent VT or persistent inducibility after ENDO-only ablation. Endocardial plus adjuvant EPI ablation was performed in 39 (63%) patients, including 13 who crossed over to ENDO-EPI after VT recurrence during follow-up, after ENDO-only ablation. Before ablation, 54 of 62 patients failed a mean of 2.4 antiarrhythmic drugs, including amiodarone in 29 (47%) patients. During follow-up of 56±44 months after the last ablation, VT-free survival was 71% with only a single VT episode in additional 9 patients (15%). At last follow-up, 39 (64%) patients were only on β-blockers or no treatment, 21 were on class 1 or 3 antiarrhythmic drugs (11 for atrial arrhythmias), and 2 were on amiodarone as a bridge to heart transplantation. The long-term outcome after ENDO and adjuvant EPI substrate ablation of VT in arrhythmogenic right ventricular cardiomyopathy is good. Most patients have complete VT control without amiodarone therapy and limited need for antiarrhythmic drugs. © 2015 American Heart Association, Inc.
Glikson, Michael; Lipchenca, Igor; Viskin, Sami; Ballman, Karla V; Trusty, Jane M; Gurevitz, Osnat T; Luria, David M; Eldar, Michael; Hammill, Stephen C; Friedman, Paul A
Evidence is inconclusive concerning the role of implantable cardioverter defibrillators (ICDs) to treat patients with hemodynamically stable ventricular tachycardia (VT). The goal of this study was to estimate future risk of unstable ventricular arrhythmias in patients who received ICDs for stable VT. We reviewed complete ICD follow-up data from 82 patients (age 66.1 +/- 11.3 years; left ventricular ejection fraction 32.3%+/- 11.2%; mean +/- SD) who received ICDs for stable VT. During the follow-up period of 23.6 +/- 21.5 months (mean +/- SD), 15 patients (18%) died, and 10 (12%) developed unstable ventricular arrhythmia, 8 of whom had the unstable arrhythmia as the first arrhythmia after ICD placement. Estimated 2- and 4-year survival in the whole group was 80% and 74%, respectively. Estimated 2- and 4-year probability of any VT and unstable VT was 67% and 77% and 11% and 25%, respectively. There were no differences in age, ejection fraction, sex, underlying heart disease, cycle length, symptoms, baseline electrophysiologic study results, or QRS characteristics of qualifying VT between patients who developed unstable ventricular arrhythmia and patients who did not. Twenty-nine patients (35%) had at least one inappropriate shock, and 11 (13%) underwent further surgery for ICD-related complications. Patients who present with hemodynamically stable VT are at risk for subsequent unstable VT. ICD treatment offers potential salvage of patients with stable VT who subsequently develop unstable VT/ventricular fibrillation, although complications and inappropriate shocks are considerable. No predictors could be found for high and low risk for unstable arrhythmias. These findings support ICD treatment for stable VT survivors.
Wu, Ling-Min; Bao, Jing-Ru; Yao, Yan; Hou, Bing-Bo; Zheng, Li-Hui; Zhang, Shu
One of the major challenges in arrhythmogenic right ventricular cardiomyopathy (ARVC) ablation is ventricular tachycardia (VT) non-inducibility. The study aimed to assess whether fast rate (≥ 250 beats/min) right ventricular burst stimulation was useful for VT induction in patients with ARVC. Ninety-one consecutive ARVC patients with clinical sustained VT that underwent electrophysiological study were enrolled. The stimulation protocol was implemented at both right ventricular apex and outflow tract as follows: Step A, up to double extra-stimuli; Step B, incremental stimulation with low rate (< 250 beats/min); Step C, burst stimulation with fast rate (≥ 250 beats/min); Step D, repeated all steps above with intravenous infusion of isoproterenol. A total of 76 patients had inducible VT (83.5%), among which 49 were induced by Step C, 15 were induced by Step B, 8 and 4 by Step A and D, respectively. Clinical VTs were induced in 60 patients (65.9%). Only two spontaneously ceased ventricular fibrillations were induced by Step C. Multivariate analysis showed that a narrower baseline QRS duration under sinus rhythm was independently associated with VT non-inducibility (OR: 1.1; 95% CI: 1.0-1.1; P = 0.019). Fast rate (≥ 250 beats/min) right ventricular burst stimulation provides a useful supplemental method for VT induction in ARVC patients.
Ghanbari, Hamid; Baser, Kazim; Yokokawa, Miki; Stevenson, William; Della Bella, Paolo; Vergara, Pasquale; Deneke, Thomas; Kuck, Karl-Heinz; Kottkamp, Hans; Fei, She; Morady, Fred; Bogun, Frank
Although ventricular tachycardia (VT) ablation is a widely used therapy for patients with VT, the ideal end points for this procedure are not well defined. We performed a meta-analysis of the published literature to assess the predictive value of noninducibility of postinfarction VT for long-term outcomes after VT ablation. We performed a systematic review of MEDLINE (1950-2013), EMBASE (1988-2013), the Cochrane Controlled Trials Register (Fourth Quarter, 2012), and reports presented at scientific meetings (1994-2013). Randomized controlled trials, case-control, and cohort studies of VT ablation were included. Outcomes reported in eligible studies were freedom from VT/ventricular fibrillation and all-cause mortality. Of the 3895 studies evaluated, we identified 8 cohort studies enrolling 928 patients for the meta-analysis. Noninducibility after VT ablation was associated with a significant increase in arrhythmia-free survival compared with partial success (odds ratio, 0.49; 95% confidence interval, 0.29-0.84; P=0.009) or failed ablation procedure (odds ratio, 0.10; 95% confidence interval, 0.06-0.18; P<0.001). There was also a significant reduction in all-cause mortality if patients were noninducible after VT ablation compared with patients with partial success (odds ratio, 0.59; 95% confidence interval, 0.36-0.98; P=0.04) or failed ablation (odds ratio, 0.32; 95% confidence interval, 0.10-0.99; P=0.049). Noninducibility of VT after VT ablation is associated with improved arrhythmia-free survival and all-cause mortality. © 2014 American Heart Association, Inc.
Yang, Pei‐Chi; Moreno, Jonathan D.; Miyake, Christina Y.; Vaughn‐Behrens, Steven B.; Jeng, Mao‐Tsuen; Grandi, Eleonora; Wehrens, Xander H. T.; Noskov, Sergei Y.
Key points The mechanism of therapeutic efficacy of flecainide for catecholaminergic polymorphic ventricular tachycardia (CPVT) is unclear.Model predictions suggest that Na+ channel effects are insufficient to explain flecainide efficacy in CPVT.This study represents a first step toward predicting therapeutic mechanisms of drug efficacy in the setting of CPVT and then using these mechanisms to guide modelling and simulation to predict alternative drug therapies. Abstract Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by fatal ventricular arrhythmias in structurally normal hearts during β‐adrenergic stimulation. Current treatment strategies include β‐blockade, flecainide and ICD implementation – none of which is fully effective and each comes with associated risk. Recently, flecainide has gained considerable interest in CPVT treatment, but its mechanism of action for therapeutic efficacy is unclear. In this study, we performed in silico mutagenesis to construct a CPVT model and then used a computational modelling and simulation approach to make predictions of drug mechanisms and efficacy in the setting of CPVT. Experiments were carried out to validate model results. Our simulations revealed that Na+ channel effects are insufficient to explain flecainide efficacy in CPVT. The pure Na+ channel blocker lidocaine and the antianginal ranolazine were additionally tested and also found to be ineffective. When we tested lower dose combination therapy with flecainide, β‐blockade and CaMKII inhibition, our model predicted superior therapeutic efficacy than with flecainide monotherapy. Simulations indicate a polytherapeutic approach may mitigate side‐effects and proarrhythmic potential plaguing CPVT pharmacological management today. Importantly, our prediction of a novel polytherapy for CPVT was confirmed experimentally. Our simulations suggest that flecainide therapeutic efficacy in CPVT is unlikely
Wang, Linwei; Gharbia, Omar A; Horáček, B Milan; Sapp, John L
The majority of life-threatening ventricular tachycardias (VTs) are sustained by heterogeneous scar substrates with narrow strands of surviving tissue. An effective treatment for scar-related VT is to modify the underlying scar substrate by catheter ablation. If activation sequence and entrainment mapping can be performed during sustained VT, the exit and isthmus of the circuit can often be identified. However, with invasive catheter mapping, only monomorphic VT that is hemodynamically stable can be mapped in this manner. For the majority of patients with poorly tolerated VTs or multiple VTs, a close inspection of the re-entry circuit is not possible. A noninvasive approach to fast mapping of unstable VTs can potentially allow an improved identification of critical ablation sites. For patients who underwent catheter ablation of scar-related VT, CT scan was obtained prior to the ablation procedure and 120-lead body-surface electrocardiograms (ECGs) were acquired during induced VTs. These data were used for noninvasive ECG imaging to computationally reconstruct electrical potentials on the epicardium and on the endocardium of both ventricles. Activation time and phase maps of the VT circuit were extracted from the reconstructed electrograms. They were analyzed with respect to scar substrate obtained from catheter mapping, as well as VT exits confirmed through ablation sites that successfully terminated the VT. The reconstructed re-entry circuits correctly revealed both epicardial and endocardial origins of activation, consistent with locations of exit sites confirmed from the ablation procedure. The temporal dynamics of the re-entry circuits, particularly the slowing of conduction as indicated by the crowding and zig-zag conducting of the activation isochrones, collocated well with scar substrate obtained by catheter voltage maps. Furthermore, the results indicated that some re-entry circuits involve both the epicardial and endocardial layers, and can only be
Van Herendael, Hugo; Dorian, Paul
Amiodarone has emerged as the leading antiarrhythmic therapy for termination and prevention of ventricular arrhythmia in different clinical settings because of its proven efficacy and safety. In patients with shock refractory out-of-hospital cardiac arrest and hemodynamically destabilizing ventricular arrhythmia, amiodarone is the most effective drug available to assist in resuscitation. Although the superiority of the transvenous implantable cardioverter defibrillator (ICD) over amiodarone has been well established in the preventive treatment of patients at high risk of life-threatening ventricular arrhythmias, amiodarone (if used with a beta-blocker) is the most effective antiarrhythmic drug to prevent ICD shocks and treat electrical storm. Both the pharmacokinetics and the electrophysiologic profile of amiodarone are complex, and its optimal and safe use requires careful patient surveillance with respect to potential adverse effects.
Van Herendael, Hugo; Dorian, Paul
Amiodarone has emerged as the leading antiarrhythmic therapy for termination and prevention of ventricular arrhythmia in different clinical settings because of its proven efficacy and safety. In patients with shock refractory out-of-hospital cardiac arrest and hemodynamically destabilizing ventricular arrhythmia, amiodarone is the most effective drug available to assist in resuscitation. Although the superiority of the transvenous implantable cardioverter defibrillator (ICD) over amiodarone has been well established in the preventive treatment of patients at high risk of life-threatening ventricular arrhythmias, amiodarone (if used with a beta-blocker) is the most effective antiarrhythmic drug to prevent ICD shocks and treat electrical storm. Both the pharmacokinetics and the electrophysiologic profile of amiodarone are complex, and its optimal and safe use requires careful patient surveillance with respect to potential adverse effects. PMID:20730062
Kaneko, Yoshiaki; Nakajima, Tadashi; Irie, Tadanobu; Igawa, Osamu; Iijima, Takafumi; Ota, Masaki; Tamura, Mio; Iizuka, Takashi; Tamura, Shuntaro; Saito, Akihiro; Kurabayashi, Masahiko
After entrainment pacing, the postpacing interval of a diastolic potential may be misinterpreted if the distal tip of the ablation catheter captures a remote bystander pathway adjacent to the critical isthmus of a complex reentrant circuit in a structurally diseased heart. We discuss this possible pitfall of entrainment mapping of reentrant ventricular tachycardia, observed after a healed myocardial infarction.
Hammwöhner, Matthias; Stachowitz, Jörg; Willich, Tobias; Goette, Andreas
Pulmonary vein isolation in a dual-chamber pacemaker patient using the pulmonary vein ablation catheter (PVAC) system resulted in perpetual induction of ventricular tachycardia (VT) during radio frequency energy application. Induction of VT was abolished by programming the PVAC-system to a pure bipolar ablation mode. Patients with implanted devices should be closely monitored when using the PVAC system in unipolar modes.
Cardinal, R; Scherlag, B J; Vermeulen, M; Armour, J A
To investigate mechanisms of ventricular impulse formation in response to sympathetic stimulation in the healthy canine heart in situ, we compared the patterns of ventricular activation during the idioventricular rhythms arising after complete atrioventricular (AV) block and ventricular tachycardias induced by RSG or LSG stimulation. Isochronal maps were generated by computer from 116-127 unipolar electrograms recorded from the entire ventricular epicardium in 15 open chest, anesthetized dogs. In eight of these, bipolar electrograms were recorded with plunge electrodes from 11 selected endocardial sites located below epicardial breakthrough areas. Intracardiac recordings from the His-Purkinje system were made with electrode catheters. After electrograms were recorded during sinus rhythm, complete AV block was induced by injecting formaldehyde into the AV node and idioventricular rhythms occurred spontaneously at a rate of 37 +/- 12 beats/min (mean +/- SD, n = 25). During idioventricular rhythms, endocardial activation preceded the earliest epicardial breakthrough, which occurred in either the right anterior paraseptal region, antero-apical left ventricle, or postero-apical left ventricle. These sites were consistent with a focal origin in the subendocardial His-Purkinje system. Total epicardial activation times lasted for 47 +/- 13 msec (n = 40). Idioventricular rhythms were suppressed by overdrive pacing (intermittent trains of ten beats with decremental cycle length from 500 to 200 msec) or by intravenous calcium infusion (to plasma levels of 10.1-15.2 mM). Right or left stellate ganglion stimulation increased idioventricular rhythm rates (to 52 +/- 13 beats/min, n = 28) and also induced, in all preparations, ventricular tachycardias that had significantly faster rates (189 +/- 55 beats/min, n = 27, P less than 0.005). Ventricular fibrillation was induced after brief runs of ventricular tachycardia in five of the preparations. During ventricular tachycardias
Iwai, Sei; Cantillon, Daniel J; Kim, Robert J; Markowitz, Steven M; Mittal, Suneet; Stein, Kenneth M; Shah, Bindi K; Yarlagadda, Ravi K; Cheung, Jim W; Tan, Vivian R; Lerman, Bruce B
"Idiopathic" ventricular arrhythmias most often arise from the right ventricular outflow tract (RVOT), although arrhythmias from the left ventricular outflow tract (LVOT) are also observed. While previous work has elucidated the mechanism and electropharmacologic profile of RVOT arrhythmias, it is unclear whether those from the LVOT share these properties. The purpose of this study was to characterize the electropharmacologic properties of RVOT and LVOT arrhythmias. One hundred twenty-two consecutive patients (61 male; 50.9 +/- 15.2 years) with outflow tract arrhythmias comprise this series, 100 (82%) with an RVOT origin, and 22 (18%) with an LVOT origin. The index arrhythmia was similar: sustained ventricular tachycardia (VT) (RVOT = 28%, LVOT = 36%), nonsustained VT (RVOT = 40%, LVOT = 23%), and premature ventricular complexes (RVOT = 32%, LVOT = 41%) (P = 0.32). Cardiac magnetic resonance imaging and microvolt T-wave alternans results (normal/indeterminate) were also comparable. In addition, 41% with RVOT foci and 50% with LVOT foci were inducible for sustained VT (P = 0.48), and induction of VT was catecholamine dependent in a majority of patients in both groups (66% and 73%; RVOT and LVOT, respectively; P = 1.0). VT was sensitive to adenosine (88% and 78% in the RVOT and LVOT groups, respectively, P = 0.59) as well as blockade of the slow-inward calcium current (RVOT = 70%, LVOT = 80%; P = 1.00) in both groups. Electrophysiologic and pharmacologic properties, including sensitivity to adenosine, are similar for RVOT and LVOT arrhythmias. Despite disparate sites of origin, these data suggest a common arrhythmogenic mechanism, consistent with cyclic AMP-mediated triggered activity. Based on these similarities, these arrhythmias should be considered as a single entity, and classified together as "outflow tract arrhythmias."
Kreidieh, Bahij; Rodríguez-Mañero, Moisés; Schurmann, Paul; Ibarra-Cortez, Sergio Hugo; Dave, Amish S; Valderrábano, Miguel
Radiofrequency ablation (RFA) of ventricular tachycardia (VT) can fail because of inaccessibility to the VT substrate. Transarterial coronary ethanol ablation can be effective but entails arterial instrumentation risk. We hypothesized that retrograde coronary venous ethanol ablation can be an alternative bail-out approach to failed VT RFA. Out of 334 consecutive patients undergoing VT/premature ventricular contraction ablation, 7 patients underwent retrograde coronary venous ethanol ablation. Six out of 7 patients had failed RFA attempts (including epicardial in 3). Coronary venogram-guided venous mapping was performed using a 4F quadripolar catheter or an alligator-clip-connected angioplasty wire. Targeted veins included those with early presystolic potentials and pace-maps matching VT/premature ventricular contraction. An angioplasty balloon (1.5-2×6 mm) was used to deliver 1 to 4 cc of 98% ethanol into a septal branch of the anterior interventricular vein in 5 patients with left ventricular summit VT, a septal branch of the middle cardiac vein, and a posterolateral coronary vein (n=1 each). The clinical VT was successfully ablated acutely in all patients. There were no complications of retrograde coronary venous ethanol ablation, but 1 patient developed pericardial and pleural effusion attributed to pericardial instrumentation. On follow-up of 590±722 days, VT recurred in 4 out of 7 patients, 3 of whom were successfully reablated with RFA. Retrograde coronary venous ethanol ablation is safe and feasible as a bail-out approach to failed VT RFA, particularly those originating from the left ventricular summit. © 2016 American Heart Association, Inc.
Janardhan, Ajit H.; Li, Wenwen; Fedorov, Vadim V.; Yeung, Michael; Wallendorf, Michael J.; Schuessler, Richard B.; Efimov, Igor R.
Objectives To develop a low-energy electrotherapy that terminates ventricular tachycardia (VT) when anti-tachycardia pacing (ATP) fails. Background High-energy ICD shocks are associated with device failure, significant morbidity and increased mortality. A low-energy alternative to ICD shocks is desirable. Methods Myocardial infarction (MI) was created in 25 dogs. Sustained, monomorphic VT was induced by programmed stimulation. Defibrillation electrodes were placed in the RV apex, and coronary sinus (CS) and LV epicardium (LVP). If ATP failed to terminate sustained VT, the defibrillation thresholds (DFTs) of standard versus experimental electrotherapies were measured. Results Sustained VT ranged from 276–438 bpm (mean 339 bpm). The RV-CS shock vector had lower impedance than RV-LVP (54.4±18.1 Ω versus 109.8±16.9, Ω p<0.001). A single shock required between 0.3±0.2 J to 5.9±2.5 J (mean 2.64±3.22 J; p=0.008) to terminate VT, and varied depending upon the phase of the VT cycle at which it was delivered. In contrast, multiple shocks delivered within 1 VT cycle length were not phase-dependent and achieved lower DFT compared to a single shock (0.13±0.09 J for 3 shocks, 0.08±0.04 J for 5 shocks, 0.09±0.07 J for 7 shocks; p<0.001). Finally, a multi-stage electrotherapy (MSE) achieved significantly lower DFT compared to a single biphasic shock (0.03±0.05 J versus 2.37±1.20 J, respectively, p<0.001). At a peak shock amplitude of 20 V, MSE achieved 91.3% of terminations versus 10.5% for a biphasic shock (p<0.001). Conclusions MSE achieved a major reduction in DFT compared to a single biphasic shock for ATP-refractory monomorphic VT, and represents a novel electrotherapy to reduce high-energy ICD shocks. PMID:23141483
Kim, Na Young; Kang, Jung Kyu; Park, Sun Hee; Bae, Myung Hwan; Lee, Jang Hoon; Yang, Dong Heon; Park, Hun Sik; Chae, Shung Chull; Jun, Jae Eun; Cho, Yongkeun
A 16-year-old male with a prior history of recurrent syncope was referred to our hospital after being resuscitated from cardiac arrest developed while playing volleyball. His electrocardiogram (ECG) demonstrated ventricular fibrillation at a local emergency department. After referral, an ECG showed bidirectional ventricular tachycardia (VT) and nonsustained Torsade de Pointes. Two days later, his heart rate became regular, and no additional episodes of VT were observed. His ECG showed sinus rhythm with a corrected QT interval of 423 msec, and two-dimensional echocardiography was unremarkable. We made the diagnosis of a catecholaminergic polymorphic VT. However, only premature ventricular complex bigeminy was induced on exercise ECG and epinephrine infusion tests, and the patient showed no episodes of syncope. His father and mother had different missense mutations in the cardiac ryanodine receptor on genetic testing. The proband had both mutations in different alleles and was symptomatic. It was recommended that the patient avoid competitive physical activities, and a β-blocker was prescribed.
Goya, Masahiko; Fukunaga, Masato; Hiroshima, Ken-ichi; Hayashi, Kentaro; Makihara, Yu; Nagashima, Michio; An, Yoshimori; Ohe, Seiji; Yamashita, Kennosuke; Ando, Kenji; Yokoi, Hiroyoshi; Iwabuchi, Masashi; Katayama, Kouji; Ito, Tomoaki; Niu, Harushi
Background Catheter ablation of ventricular tachycardia (VT) is feasible. However, the long-term outcomes for different underlying diseases have not been well defined. Methods Eighty-eight consecutive patients who underwent catheter ablation of VT using a three-dimensional mapping system were analyzed. The primary endpoint was any VT or ventricular fibrillation (VF) recurrence. Secondary endpoints were a composite of death or any VT/VF recurrence. Underlying heart diseases were remote myocardial infarction (remote MI) in 51 patients and non-ischemic cardiomyopathy in 37 (arrhythmogenic right ventricular cardiomyopathy [ARVC] in 18 patients, and dilated cardiomyopathy [NIDCM] in 19). Results Acute success was achieved in 82 of 88 (93%) patients. During a follow-up period of 39.2±4.6 months, VT recurred in 26 of 87 (30%), and VT/VF recurrence or death occurred in 39 of 87 (45%) patients. ARVC had better outcomes than NIDCM for the primary (p<0.05) and secondary endpoints (p<0.05). Remote MI-VT revealed a midrange outcome. Conclusions The long-term outcomes after catheter ablation of VT varied according to the underlying heart disease. ARVC-VT ablation was associated with better long-term prognosis than NIDCM. Remote MI-VT demonstrated a midrange outcome. PMID:26336519
Iwa, T; Misaki, T; Kawasuji, M; Matsunaga, Y; Tsubota, M; Matsumoto, Y
Drug resistant, non-ischemic ventricular tachycardia (VT) was treated in 43 patients by direct surgery based on electrophysiological data. Two main surgical techniques were employed: myocardium was resected followed by cryocoagulation with a special probe in 23 patients with VT originating from the right ventricle. The myocardium was incised followed by cryocoagulation in 10 patients with VT from the left ventricle. The follow-up period ranged from 1 week to 10 years, 4 weeks (mean 3 years, 8 months). After operation, 36 patients (83%) showed complete disappearance of VT without antiarrhythmic therapy. Of these 2 patients died of congestive heart failure not related to VT in the postoperative period at 1 year 4 months, and 2 years 4 months, respectively. In 7 patients, VT remained. In 2, VT disappeared after catheter ablation. In 3 patients, VT became controllable with antiarrhythmic therapy. Operation was not successful in 2 patients (5%); 1 with a giant left ventricular aneurysm died of low cardiac output syndrome due to VT 1 week after operation; the other with arrhythmogenic right ventricular dysplasia originating from both ventricles died suddenly 5 months after operation. The 10-year survival is 89%, and the 10-year freedom from recurrent VT is 83%. These results indicate that surgical management for non-ischemic VT is safe and effective with a high chance of cure.
Goya, Masahiko; Fukunaga, Masato; Hiroshima, Ken-Ichi; Hayashi, Kentaro; Makihara, Yu; Nagashima, Michio; An, Yoshimori; Ohe, Seiji; Yamashita, Kennosuke; Ando, Kenji; Yokoi, Hiroyoshi; Iwabuchi, Masashi; Katayama, Kouji; Ito, Tomoaki; Niu, Harushi
Catheter ablation of ventricular tachycardia (VT) is feasible. However, the long-term outcomes for different underlying diseases have not been well defined. Eighty-eight consecutive patients who underwent catheter ablation of VT using a three-dimensional mapping system were analyzed. The primary endpoint was any VT or ventricular fibrillation (VF) recurrence. Secondary endpoints were a composite of death or any VT/VF recurrence. Underlying heart diseases were remote myocardial infarction (remote MI) in 51 patients and non-ischemic cardiomyopathy in 37 (arrhythmogenic right ventricular cardiomyopathy [ARVC] in 18 patients, and dilated cardiomyopathy [NIDCM] in 19). Acute success was achieved in 82 of 88 (93%) patients. During a follow-up period of 39.2±4.6 months, VT recurred in 26 of 87 (30%), and VT/VF recurrence or death occurred in 39 of 87 (45%) patients. ARVC had better outcomes than NIDCM for the primary (p<0.05) and secondary endpoints (p<0.05). Remote MI-VT revealed a midrange outcome. The long-term outcomes after catheter ablation of VT varied according to the underlying heart disease. ARVC-VT ablation was associated with better long-term prognosis than NIDCM. Remote MI-VT demonstrated a midrange outcome.
Guo, Jin-Rui; Zheng, Li-Hui; Wu, Ling-Min; Ding, Li-Gang; Yao, Yan
Abstract Left ventricular aneurysm (LVA) postmyocardial infarction (MI) might be an arrhythmogenic substrate. We examined the safety and efficacy of catheter ablation of LVA-related ventricular tachycardia (VT). Thirty-three consecutive patients who underwent primary catheter ablation of ischemic VT were divided into LVA group (11 patients, mean age 61.9 years, 10 men) and none LVA group. Acute procedural outcomes, complications, and long-term outcomes were assessed. In LVA group, average number of induced VTs were 3.2 ± 2.6 (range 1–7), clinical VTs were located in the ventricular septum scar zone in 4 (36.4%) patients, acute success was achieved in 7 (63.6%) patients, partial success in 3 (27.3%) and failure in 1 patient, while none LVA group showing a statistically similar distribution of acute procedural outcomes (P = 0.52). There were no major or life-threatening complications. VT-free survival rate at median 19 (1–44) months follow-up was numerically but not significantly lower in LVA versus none LVA group (48.5% vs 62.8%, log-rank P = 0.40). Catheter ablation of ischemic VT in the presence of LVA appears feasible and effective, with about one-third of cases having septal ablation targets. Further studies are warranted. PMID:28353573
Saad, Antonio F.; Monsivais, Luis; Pacheco, Luis D.
Background Despite its seldom occurrence, fetal tachycardia can lead to poor fetal outcomes including hydrops and fetal death. Management can be challenging and result in maternal adverse effects secondary to high serum drug levels required to achieve effective transplacental antiarrhythmic drug therapy. Case A 33-year-old woman at 33 weeks of gestation with a diagnosis of a fetal sustained superior ventricular tachycardia developed chest pain, shortness of breath, and bigeminy on electrocardiogram secondary to digoxin toxicity despite subtherapeutic serum drug levels. She required supportive care with repletion of corresponding electrolyte abnormalities. After resolution of cardiac manifestations of digoxin toxicity, the patient was discharged home. The newborn was discharged at day 9 of life on maintenance amiodarone. Conclusion We describe an interesting case of digoxin toxicity with cardiac manifestations of digoxin toxicity despite subtherapeutic serum drug levels. This case report emphasizes the significance of instituting an early diagnosis of digoxin toxicity during pregnancy, based not only on serum drug levels but also on clinical presentation. In cases of refractory supportive care, digoxin Fab fragment antibody administration should be considered. With timely diagnosis and treatment, excellent maternal and perinatal outcomes can be achieved. PMID:27516921
Saad, Antonio F; Monsivais, Luis; Pacheco, Luis D
Despite its seldom occurrence, fetal tachycardia can lead to poor fetal outcomes including hydrops and fetal death. Management can be challenging and result in maternal adverse effects secondary to high serum drug levels required to achieve effective transplacental antiarrhythmic drug therapy. A 33-year-old woman at 33 weeks of gestation with a diagnosis of a fetal sustained superior ventricular tachycardia developed chest pain, shortness of breath, and bigeminy on electrocardiogram secondary to digoxin toxicity despite subtherapeutic serum drug levels. She required supportive care with repletion of corresponding electrolyte abnormalities. After resolution of cardiac manifestations of digoxin toxicity, the patient was discharged home. The newborn was discharged at day 9 of life on maintenance amiodarone. We describe an interesting case of digoxin toxicity with cardiac manifestations of digoxin toxicity despite subtherapeutic serum drug levels. This case report emphasizes the significance of instituting an early diagnosis of digoxin toxicity during pregnancy, based not only on serum drug levels but also on clinical presentation. In cases of refractory supportive care, digoxin Fab fragment antibody administration should be considered. With timely diagnosis and treatment, excellent maternal and perinatal outcomes can be achieved.
Ramirez, L. J.; Lozano, F. A.; Rondon, C. R.
Sustained ventricular tachycardia (VTs) can be asymptomatic for some people, but for other is deadly because it is a major cause of sudden cardiac death . Some patients may present this arrhythmia, and even so, they decide to drive car increasing the likelihood of VTs, putting at risk not only his life but that of the other drivers. We developed a system for early detection of VTs, consisting of EKG sensors, a card of processing and a cell phone, which detects this arrhythmia, gives an alarm signal to the driver, and it simultaneously sending to text messages a specialist doctor and a relative or friend, all in real time. This design was conditioned to the car, is light and comfortable, that allowed that work of car's driver without discomfort. This system will save lives, since in case of emergency sends a help message, no matter where you are in the driver.
Liang, Jackson J; Santangeli, Pasquale; Callans, David J
Ventricular tachycardia (VT) often occurs in the setting of structural heart disease and can affect patients with ischaemic or nonischaemic cardiomyopathies. Implantable cardioverter-defibrillators (ICDs) provide mortality benefit and are therefore indicated for secondary prevention in patients with sustained VT, but they do not reduce arrhythmia burden. ICD shocks are associated with increased morbidity and mortality, and antiarrhythmic medications are often used to prevent recurrent episodes. Catheter ablation is an effective treatment option for patients with VT in the setting of structural heart disease and, when successful, can reduce the number of ICD shocks. However, whether VT ablation results in a mortality benefit remains unclear. We aim to review the long-term outcomes in patients with different types of structural heart disease treated with VT ablation. PMID:26835122
Monomorphic ventricular tachycardia (VT) in patients with post-infarction cardiomyopathy (CMP) is caused by reentry through slowly conducting tissue with in areas of myocardial scar. The use of implantable cardioverter-defibrillators (ICDs) has helped to decrease the risk of arrhythmic death in patients with post-infarction CMP, but the symptomatic and psychological burden of ICD shocks remains significant. Experience with catheter ablation has progressed substantially in the past 20 years, and is now routinely used to treat patients with post-infarction CMP who experience VT or receive ICD therapy. Depending on the hemodynamic tolerance of VT, a variety of mapping techniques may be used to identify sites for catheter ablation, including activation and entrainment mapping for mappable VTs, or substrate mapping for unmappable VTs. In this review, we discuss the pathophysiology of VT in post-infarction CMP patients, and the contemporary practice of catheter ablation. PMID:25089131
Rao, D Sheshagiri; Barik, Ramachandra
Arterial supply of an intralobar pulmonary sequestration (IPS) from the coronary circulation is extremely rare. A significant coronary steal does not occur because of dual or triple sources of blood supply to sequestrated lung tissue. We present a 60-year-old woman who presented to us with repeated episodes of monomorphic ventricular tachycardia (VT) in last 3 mo. Radio frequency ablation was ineffective. On evaluation, she had right lower lobe IPS with dual arterial blood supply, i.e., right pulmonary artery and the systemic arterial supply from the right coronary artery (RCA). Stress myocardial perfusion scan revealed significant inducible ischemia in the RCA territory. Coronary angiogram revealed critical stenosis of proximal RCA just after the origin of the systemic artery supplying IPS. The critical stenosis in the RCA was stented. At 12 mo follow-up, she had no further episodes of VT or angina.
Rao, D Sheshagiri; Barik, Ramachandra
Arterial supply of an intralobar pulmonary sequestration (IPS) from the coronary circulation is extremely rare. A significant coronary steal does not occur because of dual or triple sources of blood supply to sequestrated lung tissue. We present a 60-year-old woman who presented to us with repeated episodes of monomorphic ventricular tachycardia (VT) in last 3 mo. Radio frequency ablation was ineffective. On evaluation, she had right lower lobe IPS with dual arterial blood supply, i.e., right pulmonary artery and the systemic arterial supply from the right coronary artery (RCA). Stress myocardial perfusion scan revealed significant inducible ischemia in the RCA territory. Coronary angiogram revealed critical stenosis of proximal RCA just after the origin of the systemic artery supplying IPS. The critical stenosis in the RCA was stented. At 12 mo follow-up, she had no further episodes of VT or angina. PMID:27468336
Nagra, Bipinpreet; Liu, Zhengou; Mehta, Rohit; Hart, David; Kantharia, Bharat K
Verapamil-sensitive fascicular ventricular tachycardia (VT) of right bundle branch block (RBBB) and superior axis pattern is typically seen in young patients with structurally normal hearts and considered "idiopathic". Recently, involvement of the Purkinje system in post-infarction monomorphic VT that mimics such idiopathic fascicular VT has been described. In this report we describe a case of a patient who following myocardial infarction developed left posterior fascicular Purkinje reentrant VT that was sensitive to verapamil. The VT was successfully treated by radiofrequency ablation guided by three dimensional electroanatomical CARTO mapping. Our case highlights that involvement of Purkinje fibers should be considered in post infarction patients with VT of narrow QRS duration, RBBB morphology and superior axis. Recognition of such VT is clinically important, as this arrhythmia is amenable to curative catheter ablation.
Lin, Chin-Yu; Chang, Shih-Lin; Chung, Fa-Po; Chen, Yun-Yu; Lin, Yenn-Jiang; Lo, Li-Wei; Hu, Yu-Feng; Tuan, Ta-Chuan; Chao, Tze-Fan; Liao, Jo-Nan; Chang, Yao-Ting; Lin, Chung-Hsing; Allamsetty, Suresh; Walia, Rohit; Te, Abigail Louise D; Yamada, Shinya; Chiang, Shuo-Ju; Tsao, Hsuan-Ming; Chen, Shih-Ann
The impact of non-sustained ventricular tachycardia (NSVT) on the risk of thromboembolic event and clinical outcomes in patients without structural heart disease remains undetermined. This study aimed to evaluate the association between NSVT and clinical outcomes. The study population of 5903 patients was culled from the "Registry of 24-hour ECG monitoring at Taipei Veterans General Hospital" (REMOTE database) between January 1, 2002 and December 31, 2004. Of that total, we enrolled 3767 patients without sustained ventricular tachycardia, structural heart disease, and permanent pacemaker. For purposes of this study, NSVT was defined as 3 or more consecutive beats arising below the atrioventricular node with an RR interval of <600 ms (>100 beats/min) and lasting < 30 seconds. There were 776 deaths, 2042 hospitalizations for any reason, 638 cardiovascular (CV)-related hospitalizations, 350 ischemic strokes, 409 transient ischemic accident (TIA), 368 new-onset heart failure (HF), and 260 new-onset atrial fibrillation (AF) with a mean follow-up duration of 10 ± 1 years. In multivariate analysis, the presence of NSVT was independently associated with death (hazard ratio [HR]: 1.362, 95% confidence interval [CI]: 1.071-1.731), CV hospitalization (HR: 1.527, 95% CI: 1.171-1.992), ischemic stroke (HR: 1.436, 95% CI: 1.014-2.032), TIA (HR 1.483, 95% CI: 1.069-2.057), and new-onset HF (HR: 1.716, 95% CI: 1.243-2.368). There was no significant association between the presence of NSVT and all-cause hospitalization or new-onset AF. In patients without structural heart disease, presence of NSVT on 24-hour monitoring was independently associated with death, CV hospitalization, ischemic stroke, TIA, and new onset heart failure.
Liu, Yaowu; Fang, Zhen; Yang, Bing; Kojodjojo, Pipin; Chen, Hongwu; Ju, Weizhu; Cao, Kejiang; Chen, Minglong; Zhang, Fengxiang
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. 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. 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. © 2015 The Authors.
Gray, Belinda; Bagnall, Richard D.; Lam, Lien; Ingles, Jodie; Turner, Christian; Haan, Eric; Davis, Andrew; Yang, Pei-Chi; Clancy, Colleen E.; Sy, Raymond W.; Semsarian, Christopher
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal inherited arrhythmia syndrome characterized by adrenergically stimulated ventricular tachycardia. Mutations in the cardiac ryanodine receptor gene (RYR2) cause an autosomal dominant form of CPVT, while mutations in the cardiac calsequestrin 2 gene (CASQ2) cause an autosomal recessive form. Objective The aim of this study was to clinically and genetically evaluate a large family with severe autosomal dominant CPVT. Methods Clinical evaluation of family members was performed, including detailed history, physical examination, electrocardiogram, exercise stress test, and autopsy review of decedents. We performed genome-wide linkage analysis in 12 family members and exome sequencing in 2 affected family members. In silico models of mouse and rabbit myocyte electrophysiology were used to predict potential disease mechanisms. Results Severe CPVT with dominant inheritance in 6 members was diagnosed in a large family with 2 sudden deaths, 2 resuscitated cardiac arrests, and multiple appropriate implantable cardioverter-defibrillator shocks. A comprehensive analysis of cardiac arrhythmia genes did not reveal a pathogenic variant. Exome sequencing identified a novel heterozygous missense variant in CASQ2 (Lys180Arg) affecting a highly conserved residue, which cosegregated with disease and was absent in unaffected family members. Genome-wide linkage analysis confirmed a single linkage peak at the CASQ2 locus (logarithm of odds ratio score 3.01; θ = 0). Computer simulations predicted that haploinsufficiency was unlikely to cause the severe CPVT phenotype and suggested a dominant negative mechanism. Conclusion We show for the first time that a variant in CASQ2 causes autosomal dominant CPVT. Genetic testing in dominant CPVT should include screening for heterozygous CASQ2 variants. PMID:27157848
Lin, Chin-Yu; Chang, Shih-Lin; Chung, Fa-Po; Chen, Yun-Yu; Lin, Yenn-Jiang; Lo, Li-Wei; Hu, Yu-Feng; Tuan, Ta-Chuan; Chao, Tze-Fan; Liao, Jo-Nan; Chang, Yao-Ting; Lin, Chung-Hsing; Allamsetty, Suresh; Walia, Rohit; Te, Abigail Louise D.; Yamada, Shinya; Chiang, Shuo-Ju; Tsao, Hsuan-Ming; Chen, Shih-Ann
Background The impact of non-sustained ventricular tachycardia (NSVT) on the risk of thromboembolic event and clinical outcomes in patients without structural heart disease remains undetermined. This study aimed to evaluate the association between NSVT and clinical outcomes. Methods The study population of 5903 patients was culled from the “Registry of 24-hour ECG monitoring at Taipei Veterans General Hospital” (REMOTE database) between January 1, 2002 and December 31, 2004. Of that total, we enrolled 3767 patients without sustained ventricular tachycardia, structural heart disease, and permanent pacemaker. For purposes of this study, NSVT was defined as 3 or more consecutive beats arising below the atrioventricular node with an RR interval of <600 ms (>100 beats/min) and lasting < 30 seconds. Result There were 776 deaths, 2042 hospitalizations for any reason, 638 cardiovascular (CV)-related hospitalizations, 350 ischemic strokes, 409 transient ischemic accident (TIA), 368 new-onset heart failure (HF), and 260 new-onset atrial fibrillation (AF) with a mean follow-up duration of 10 ± 1 years. In multivariate analysis, the presence of NSVT was independently associated with death (hazard ratio [HR]: 1.362, 95% confidence interval [CI]: 1.071–1.731), CV hospitalization (HR: 1.527, 95% CI: 1.171–1.992), ischemic stroke (HR: 1.436, 95% CI: 1.014–2.032), TIA (HR 1.483, 95% CI: 1.069–2.057), and new-onset HF (HR: 1.716, 95% CI: 1.243–2.368). There was no significant association between the presence of NSVT and all-cause hospitalization or new-onset AF. Conclusion In patients without structural heart disease, presence of NSVT on 24-hour monitoring was independently associated with death, CV hospitalization, ischemic stroke, TIA, and new onset heart failure. PMID:27548469
AbdelWahab, Amir; Sapp, John
Ventricular tachycardia occurrence in implantable cardioverter defibrillator (ICD) patients may result in shock delivery and is associated with increased morbidity and mortality. In addition, shocks may have deleterious mechanical and psychological effects. Prevention of ventricular tachycardia (VT) recurrence with the use of antiarrhythmic drugs or catheter ablation may be warranted. Antiarrhythmic drugs are limited by incomplete efficacy and an unfavorable adverse effect profile. Catheter ablation can be effective but acute complications and long-term VT recurrence risk necessitating repeat ablation should be recognized. A shared clinical decision process accounting for patients' cardiac status, comorbidities, and goals of care is often required. There are four published randomized trials of catheter ablation for sustained monomorphic VT (SMVT) in the setting of ischemic heart disease; there are no randomized studies for non-ischemic ventricular substrates. The most recent trial is the VANISH trial which randomly allocated patients with ICD, prior infarction, and SMVT despite first-line antiarrhythmic drug therapy to catheter ablation or more aggressive antiarrhythmic drug therapy. During 28 months of follow-up, catheter ablation resulted in a 28% relative risk reduction in the composite endpoint of death, VT storm, and appropriate ICD shock (p = 0.04). In a subgroup analysis, patients having VT despite amiodarone had better outcomes with ablation as compared to increasing amiodarone dose or adding mexiletine. There is evidence for the effectiveness of both catheter ablation and antiarrhythmic drug therapy for patients with myocardial infarction, an implantable defibrillator, and VT. If sotalol is ineffective in suppressing VT, either catheter ablation or initiation of amiodarone is a reasonable option. If VT occurs despite amiodarone therapy, there is evidence that catheter ablation is superior to administration of more aggressive antiarrhythmic drug therapy
Batchvarov, Velislav N; Behr, Elijah R
We present segments from a 24-hour 12-lead digital Holter recording in a 48-year-old man demonstrating transient ST elevations in the inferior leads that triggered sustained ventricular tachycardia/ventricular fibrillation (VT/VF) requiring cardioversion. The onset of VT was preceded by a gradual increase in the ST with marked QRS broadening that lacked distinction between the end of the QRS and the beginning of the ST (QRS-ST-T "triangulation"), and shortening of the QT interval not caused by an increased heart rate. This is a relatively rare documentation of the mechanisms immediately triggering sustained ventricular arrhythmias during acute myocardial ischemia obtained with 12-lead ECG.
Moore, Jeremy P; Seki, Atsuko; Shannon, Kevin M; Mandapati, Ravi; Tung, Roderick; Fishbein, Michael C
Although catheter ablation has been used to target the critical isthmuses for re-entrant monomorphic ventricular tachycardia in tetralogy of Fallot, the anatomy and histology of these regions have not been fully characterized. Autopsy hearts with tetralogy of Fallot were evaluated to clarify the pathological substrate. Twenty-seven hearts with the diagnosis of tetralogy of Fallot were examined. Anatomically defined isthmuses included (1A) ventriculotomy-to-tricuspid annulus, (1B) ventriculotomy-to-ventricular septal defect patch, (2) ventriculotomy-to-pulmonary annulus, (3) pulmonary annulus-to-ventricular septal defect patch, and (4) ventricular septal defect patch-to-tricuspid annulus. Length and wall thickness were measured for all specimens, and light microscopy was performed for those surviving surgery. For subjects≥5 years at death, isthmuses 1A and 1B were present in 88%, isthmus 2 in 25%, isthmus 3 in 94%, and isthmus 4 in 13%. Isthmus 1A had the greatest dimensions (mean length, 3.9±1.08; thickness, 1.5±0.3 cm), isthmus 1B intermediate dimensions (mean length, 2.4±0.8; thickness, 1.1±0.4 cm), and isthmuses 2, 3, and 4 the smallest dimensions (mean length, 1.5±0.5, 1.4±0.8, and 0.6±0.4 cm; thickness, 0.5±0.2, 0.6±0.2, and 0.3±0.04 cm, respectively). Histological examination (n=7) revealed increased fibrosis in anatomic isthmuses relative to nonisthmus controls. Consistencies in isthmus dimensions and histology are found among patients with repaired tetralogy of Fallot. Isthmus 1A is associated with the largest morphological dimensions, whereas the nearby newly described isthmus 1B is significantly smaller. Of isthmuses with the smallest dimensions, isthmus 3 is the most common.
Masuda, Keita; Nogami, Akihiko; Kuroki, Kenji; Igarashi, Miyako; Sekiguchi, Yukio; Komatsu, Yuki; Kowase, Shinya; Kurosaki, Kenji; Nishihara, Shuzo; Niwa, Koichiro; Tsuchiya, Taketsugu; Igawa, Masayuki; Aonuma, Kazutaka
Catheter ablation is an effective therapy for ventricular fibrillation (VF) arising from the Purkinje system in ischemic heart disease. However, some patients experience newly emergent monomorphic ventricular tachycardia (VT) after the ablation of VF. We evaluated the prevalence and mechanism of monomorphic VT after VF ablation. Twenty-one consecutive patients with primary VF because of ischemic heart disease who underwent catheter ablation were retrospectively analyzed. Twenty of 21 patients were in electrical storm. Ventricular premature contractions triggering VF arose from the left Purkinje system and were targeted for ablation. Before the ablation, 14 of 21 patients had only VF, and the other 7 had VF and concomitant monomorphic VT. Four of the 14 patients with only VF (29%) exhibited newly emergent monomorphic VT after VF ablation. Three of these patients had Purkinje-related VTs, which were successfully eliminated by the ablation of a Purkinje network located in the same low-voltage area as the site of prior successful VF ablation. During a median follow-up of 28 months (interquartile range, 16-68 months), VF recurred in 6 of 21 patients (29%); however, there were neither electrical storms nor monomorphic VT, and all recurring arrhythmias were controlled by medical therapy alone. Over one fifth of patients with primary ischemic VF experienced newly emergent Purkinje-related monomorphic VT after VF ablation. The circuit of the monomorphic VT associated with the Purkinje network was located in the same low-voltage area as the Purkinje tissue that triggered VF and could be suppressed by additional ablation. © 2016 American Heart Association, Inc.
Cano, Óscar; Andrés, Ana; Osca, Joaquín; Alonso, Pau; Sancho-Tello, María-José; Olagüe, José; Martínez-Dolz, Luis
We sought to evaluate the safety and feasibility of a minimally fluoroscopic approach using the CARTOUNIVU module during scar-related ventricular tachycardia (VT) ablation. Consecutive patients with structural heart disease undergoing VT ablation using the CARTOUNIVU module were prospectively included and classified depending on their VT substrate: (1) ischemic VT (IVT) and (2) nonischemic VT and depending on the presence of an epicardial access. Radiation exposure parameters and major and minor procedure-related complications were registered. A near-zero fluoroscopy exposure was defined as those procedures with an effective dose ≤1 mSv. A total of 44 VT ablation procedures were performed in 41 patients (22 IVT and 19 nonischemic VT). The use of the CARTOUNIVU module resulted in low levels of radiation exposure: median total fluoroscopy time and effective dose of 6.08 (1.51-12.36) minutes and 2.15 (0.58-8.22) mSv, respectively. Patients with IVT had lower radiation exposure than patients with nonischemic VT (total fluoroscopy time, 2.53 [1.22-11.22] versus 8.51 [5.55-17.34] minutes; P=0.016). Epicardial access was associated with significantly higher levels of radiation exposure. Complications occurred in 4.9% patients, none of them being related to the use of the image integration tool. A near-zero fluoroscopy ablation could be performed in 14 of 44 procedures (32%), 43% of IVT procedures, and 50% of procedures with endocardial access only. The use of the CARTOUNIVU module during scar-related VT ablation resulted in low levels of radiation exposure. A near-zero fluoroscopy approach can be achieved in up to half of the procedures, especially in IVT patients with endocardial ablation. © 2016 American Heart Association, Inc.
Homme, Jason H; White, Roger D; Ackerman, Michael J
Prolongation of the QT interval is a known risk factor for syncope, seizures and sudden cardiac death. Most patients with QT prolongation have an acquired cause, but congenital forms of QT prolongation are being increasingly recognized. However, existing advanced cardiac life support (ACLS) treatment algorithms for prolonged QT mediated ventricular fibrillation pertains to acquired long-QT syndrome (LQTS). Here, a young patient with out-of-hospital cardiac arrest secondary to congenital LQTS illustrates critical exceptions to the current ACLS treatment algorithms for ventricular fibrillation and unstable ventricular tachycardia when QT prolongation is congenital in origin. A clarified ACLS algorithm is proposed.
Simons, G R; Newby, K H; Kearney, M M; Brandon, M J; Natale, A
The objective of this study was to assess the safety and efficacy of transvenous low energy cardioversion of atrial fibrillation in patients with ventricular tachycardia and atrial fibrillation and to study the mechanisms of proarrhythmia. Previous studies have demonstrated that cardioversion of atrial fibrillation using low energy, R wave synchronized, direct current shocks applied between catheters in the coronary sinus and right atrium is feasible. However, few data are available regarding the risk of ventricular proarrhythmia posed by internal atrial defibrillation shocks among patients with ventricular arrhythmias or structural heart disease. Atrial defibrillation was performed on 32 patients with monomorphic ventricular tachycardia and left ventricular dysfunction. Shocks were administered during atrial fibrillation (baseline shocks), isoproterenol infusion, ventricular pacing, ventricular tachycardia, and atrial pacing. Baseline shocks were also administered to 29 patients with a history of atrial fibrillation but no ventricular arrhythmias. A total of 932 baseline shocks were administered. No ventricular proarrhythmia was observed after well-synchronized baseline shocks, although rare inductions of ventricular fibrillation occurred after inappropriate T wave sensing. Shocks administered during wide-complex rhythms (ventricular pacing or ventricular tachycardia) frequently induced ventricular arrhythmias, but shocks administered during atrial pacing at identical ventricular rates did not cause proarrhythmia. The risk of ventricular proarrhythmia after well-synchronized atrial defibrillation shocks administered during narrow-complex rhythms is low, even in patients with a history of ventricular tachycardia. The mechanism of proarrhythmia during wide-complex rhythms appears not to be related to ventricular rate per se, but rather to the temporal relationship between shock delivery and the repolarization time of the previous QRS complex.
Right ventricular pacing is an independent predictor for ventricular tachycardia/ventricular fibrillation occurrence and heart failure events in patients with an implantable cardioverter-defibrillator.
Gardiwal, Ajmal; Yu, Hong; Oswald, Hanno; Luesebrink, Ulrich; Ludwig, Andreas; Pichlmaier, Andreas Maximilian; Drexler, Helmut; Klein, Gunnar
There is increasing evidence that right ventricular (RV) pacing may have detrimental effects by increasing morbidity and mortality for heart failure in implantable cardioverter-defibrillator (ICD) patients. In this study we prospectively tested the hypothesis that cumulative RV pacing increases ventricular tachycardia/ventricular fibrillation (VT/VF) occurrence (primary endpoint) and hospitalization and mortality for heart failure (secondary endpoint) in a predominantly secondary prophylactic ICD patient population. Two hundred and fifty patients were divided into two groups according to the median of cumulative RV pacing (< or =2 vs. >2%) and prospectively followed-up for occurrence of primary and secondary endpoints for 18 +/- 4 months. Established predictors for VT/VF occurrence and heart failure events such as age, left ventricular ejection fraction (EF), QRS duration, history of atrial fibrillation, and NT-proBNP were collected at enrollment. Multivariate Cox regression analysis revealed that cumulative RV pacing > 2% and EF < 40% were independent predictors for VT/VF occurrence and heart failure events. Kaplan-Meier analysis showed that patients with >2% cumulative RV pacing more frequently suffered from VT/VF occurrence and heart failure hospitalization. Cumulative RV pacing > 2% and EF < 40% are independent predictors for VT/VF occurrence and mortality and hospitalization for heart failure in predominantly secondary prophylactic ICD patients. Our data show that algorithms capable of reducing cumulative RV pacing should be used more frequently in clinical practice.
Arenal, Angel; del Castillo, Silvia; Gonzalez-Torrecilla, Esteban; Atienza, Felipe; Ortiz, Mercedes; Jimenez, Javier; Puchol, Alberto; García, Javier; Almendral, Jesús
Endocardial mapping before sustained monomorphic ventricular tachycardia (SMVT) induction may reduce mapping time during tachycardia and facilitate the ablation of unmappable VT. Left ventricular electroanatomic voltage maps obtained during right ventricular apex pacing in 26 patients with chronic myocardial infarction referred for VT ablation were analyzed to identify conducting channels (CCs) inside the scar tissue. A CC was defined by the presence of a corridor of consecutive electrograms differentiated by higher voltage amplitude than the surrounding area. The effect of different levels of voltage scar definition, from 0.5 to 0.1 mV, was analyzed. Twenty-three channels were identified in 20 patients. The majority of CCs were identified when the voltage scar definition was < or =0.2 mV. Electrograms with > or =2 components were recorded more frequently at the inner than at the entrance of CCs (100% versus 75%, P< or =0.01). The activation time of the latest component was longer at the inner than at the entrance of CCs (200+/-40 versus 164+/-53 ms, P< or =0.001). Pacing from these CCs gave rise to a long-stimulus QRS interval (110+/-49 ms). Radiofrequency lesion applied to CCs suppressed the inducibility in 88% of CC-related tachycardias. During a follow-up of 17+/-11 months, 23% of the patients experienced a VT recurrence. CCs represent areas of slow conduction that can be identified in 75% of patients with SMVT. A tiered decreasing-voltage definition of the scar is critical for CC identification.
Uprichard, A. C.; Harron, D. W.
1. In a placebo-controlled study of the antiarrhythmic and electrophysiological properties of atenolol and mexiletine, programmed electrical stimulation (PES) was performed in three groups of six conscious greyhounds, 7-30 days after coronary artery ligation. 2. In the placebo group, repeated PES challenge resulted in the consistent induction of ventricular tachycardias (VT) in 4/6 dogs and ventricular fibrillation in 2/6. Atenolol prevented arrhythmia induction in 4/6 dogs, one continued to demonstrate a VT and one died (P less than 0.05 compared with placebo). In the mexiletine group 5/6 dogs continued to demonstrate a VT and one died. 3. Electrocardiographic parameters were not affected by any treatment. There was no change in blood pressure in any group but when compared with placebo, heart rate fell (P less than 0.05) after atenolol (256 micrograms kg-1) and increased (P less than 0.05) after mexiletine (16 mg kg-1). Effective (ERP) and functional (FRP) refractory periods did not change after mexiletine, but ERP was prolonged (P less than 0.05) after atenolol. 4. The results indicate that atenolol but not mexiletine is effective in preventing re-entrant arrhythmias in this conscious canine model. Antiarrhythmic efficacy may be related to a fall in heart rate and/or a prolongation of refractoriness. PMID:2924074
Lee, Hyojeong; Shin, Soo-Yong; Seo, Myeongsook; Nam, Gi-Byoung; Joo, Segyeong
Ventricular tachycardia (VT) is a potentially fatal tachyarrhythmia, which causes a rapid heartbeat as a result of improper electrical activity of the heart. This is a potentially life-threatening arrhythmia because it can cause low blood pressure and may lead to ventricular fibrillation, asystole, and sudden cardiac death. To prevent VT, we developed an early prediction model that can predict this event one hour before its onset using an artificial neural network (ANN) generated using 14 parameters obtained from heart rate variability (HRV) and respiratory rate variability (RRV) analysis. De-identified raw data from the monitors of patients admitted to the cardiovascular intensive care unit at Asan Medical Center between September 2013 and April 2015 were collected. The dataset consisted of 52 recordings obtained one hour prior to VT events and 52 control recordings. Two-thirds of the extracted parameters were used to train the ANN, and the remaining third was used to evaluate performance of the learned ANN. The developed VT prediction model proved its performance by achieving a sensitivity of 0.88, specificity of 0.82, and AUC of 0.93. PMID:27561321
Lelakowski, Jacek; Kuniewicz, Marcin; Rydlewska, Anna; Kafara, Mariusz
To assess the quality of life (QoL) in patients who underwent RF reentrant supraventricular tachycardias and ventricular ectopic beats ablation. The study group consisted of 70 patients, 21 male, mean age 39.5 +/- 8.3 y. with supraventricular tachycardias (AVNRT, AVRT) and ventricular ectopic beats (VEB) treated with RF catheter ablation. The indications for the procedure were: nodal reentry tachycardia (group A n=24), WPW syndrome (group B n=24) and ventricular ectopic beats (group C n=22). Quality of life was prospectively evaluated. All the patients completed self-administered questionnaire (SF-36), disease--specific symptoms scale (Manolisa) and exercise capacity (DASI) before and 6 months after ablation. Scores were compared with t-Student test. In all study population significant improvement in QOL was found after ablation. The improvement was significant in all eight subscales of SF-36 scale. The patients reported significant improvement as assessed by disease-specific symptoms scale and exercise capacity. Before ablation, role limitations (subscales 2 of SF-36) and exercise capacity were lower in WPW patients as compared to remaining patientss (63.5 vs. 31.3, p < 0.005 and 52.9 vs. 46.1, p < 0.05; group B vs. group A) and (52.9 vs. 39.9, p < 0.01; group B vs. group C). The treatment of reentrant supraventricular arrhythmias and ventricular ectopic beats with RF catheter ablation significantly improves quality of life. The improvement was higher in VEB patients and negative correlation between QoL and an amount of VEB was observed. Pathomechanism of supraventricular tachycardia influences parameters of QoL. Role limitations were higher in AVNRT group than AVRT group. SF-36, disease--specific symptoms (Manolisa) and DASI questionnaire are useful in the assessment of efficacy of treatment for supraventricular arrhythmias and ventricular ectopic beats.
Han, Chengzong; Pogwizd, Steven M.; Killingsworth, Cheryl R.
Single-beat imaging of myocardial activation promises to aid in both cardiovascular research and clinical medicine. In the present study we validate a three-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of simultaneous 3D intracardiac mapping to assess its capability to localize endocardial and epicardial initiation sites and image global activation sequences during pacing and ventricular tachycardia (VT) in the canine heart. Body surface potentials were measured simultaneously with bipolar electrical recordings in a closed-chest condition in healthy canines. Computed tomography images were obtained after the mapping study to construct realistic geometry models. Data analysis was performed on paced rhythms and VTs induced by norepinephrine (NE). The noninvasively reconstructed activation sequence was in good agreement with the simultaneous measurements from 3D cardiac mapping with a correlation coefficient of 0.74 ± 0.06, a relative error of 0.29 ± 0.05, and a root mean square error of 9 ± 3 ms averaged over 460 paced beats and 96 ectopic beats including premature ventricular complexes, couplets, and nonsustained monomorphic VTs and polymorphic VTs. Endocardial and epicardial origins of paced beats were successfully predicted in 72% and 86% of cases, respectively, during left ventricular pacing. The NE-induced ectopic beats initiated in the subendocardium by a focal mechanism. Sites of initial activation were estimated to be ∼7 mm from the measured initiation sites for both the paced beats and ectopic beats. For the polymorphic VTs, beat-to-beat dynamic shifts of initiation site and activation pattern were characterized by the reconstruction. The present results suggest that 3DCEI can noninvasively image the 3D activation sequence and localize the origin of activation of paced beats and NE-induced VTs in the canine heart with good accuracy. This 3DCEI technique offers the potential to aid interventional therapeutic procedures for
Berruezo, Antonio; Fernández-Armenta, Juan; Andreu, David; Penela, Diego; Herczku, Csaba; Evertz, Reinder; Cipolletta, Laura; Acosta, Juan; Borràs, Roger; Arbelo, Elena; Tolosana, Jose María; Brugada, Josep; Mont, Lluis
Ventricular tachycardia (VT) substrate ablation usually requires extensive ablation. Scar dechanneling technique may limit the extent of ablation needed. The study included 101 consecutive patients with left ventricular scar-related VT (75 ischemic patients; left ventricular ejection fraction, 36 ± 13%). Procedural end point was the elimination of all identified conducting channels (CCs) by ablation at the CC entrance followed by abolition of residual inducible VTs. By itself, scar dechanneling rendered noninducibility in 54.5% of patients; ablation of residual inducible VT increased noninducibility to 78.2%. Patients needing only scar dechanneling had a shorter procedure (213 ± 64 versus 244 ± 71 minutes; P = 0.027), fewer radiofrequency applications (19 ± 11% versus 27 ± 18%; P = 0.01), and external cardioversion/defibrillation shocks (20% versus 65.2%; P < 0.001). At 2 years, patients needing scar dechanneling alone had better event-free survival (80% versus 62%) and lower mortality (5% versus 11%). Incomplete CC-electrogram elimination was the only independent predictor (hazard ratio, 2.54 [1.06-6.10]) for the primary end point. Higher end point-free survival rates were observed in patients noninducible after scar dechanneling (log-rank P = 0.013) and those with complete CC-electrogram elimination (log-rank P = 0.013). The complications rate was 6.9%, with no deaths. Scar dechanneling alone results in low recurrence and mortality rates in more than half of patients despite the limited ablation extent required. Residual inducible VT ablation improves acute results, but patients who require it have worse outcomes. Recurrences are mainly related to incomplete CC-electrogram elimination. © 2015 American Heart Association, Inc.
Lü, Fei; Eckman, Peter M; Liao, Kenneth K; Apostolidou, Ioanna; John, Ranjit; Chen, Taibo; Das, Gladwin S; Francis, Gary S; Lei, Han; Trohman, Richard G; Benditt, David G
Catheter ablation of hemodynamically unstable ventricular tachycardia (VT) is possible with mechanical circulatory support (MCS), little is known regarding the relative safety and efficacy of different supporting devices for such procedures. Sixteen consecutive patients (aged 63 ± 11 years with left ventricular ejection fraction of 20 ± 9%) who underwent ablation of hemodynamically unstable VT were included in this study. Hemodynamic support included percutaneous (Impella® 2.5, n = 5) and implantable left ventricular assist devices (LVADs, n = 6) and peripheral cardiopulmonary bypass (CPB, n = 5). Except for 2 Impella cases, hemodynamic support was adequate (with consistent mean arterial pressure of > 60 mmHg) to permit sufficient activation mapping for ablation. In the Impella and CPB groups, mean time under hemodynamic support was 185 ± 86 min, and time in VT was 78 ± 36 min. Clinical VT could be terminated at least once by ablation in all patients except 1 case with Impella due to hemodynamic instability. Peri-procedural complications included hemolysis in 1 patient with Impella and surgical intervention for percutaneous Impella placement problems in another 2. The median number of appropriately delivered defibrillator therapies was significantly decreased from 6 in the month before VT ablation to 0 in the month following ablation (p = 0.001). Our data suggest that peripheral CPB and implantable LVAD provide adequate hemodynamic support for successful ablation of unstable VT. Impella® 2.5, on the other hand, was associated with increased risk of complications, and may not provide sufficient hemodynamic support in some cases. © 2013.
Mas, Ildefonso J.; Massumi, Ali; Harlan, Mary; Seger, John J.; Hall, Robert J.
The role of programmed ventricular stimulation (PVS) was evaluated in 12 patients with recurrent sustained ventricular tachycardia (VT) who were treated with amiodarone as the sole antiarrhythmic agent. At control PVS, sustained VT was induced in 11 patients and nonsustained VT was induced in one patient, as compared with late PVS (mean, 8.6 weeks) when sustained VT was induced in six patients and nonsustained VT was induced in five. Amiodarone significantly prolonged the patients' RR, PR, QRS, and QTc intervals, VT cycle length, and right ventricular effective refractory period. During a mean follow-up of 16 ± 13.6 months, two patients had recurrent clinical VT. In the patients in whom amiodarone therapy failed (1) sustained VT was induced during late PVS, (2) VT cycle length and symptoms during late PVS and during recurrent clinical VT were similar, and (3) the QTc failed to be prolonged significantly (32.5 ± 1.6 ms in amiodarone failure vs. 84.1 ± 27.1 ms in amiodarone success, P<0.05). It is concluded that (1) amiodarone in high-risk patients is clinically effective (88.3%), (2) patients with noninducible VT or nonsustained VT during late PVS did not have recurrent clinical VT, (3) late PVS is probably predictive of electrophysiologic and hemodynamic consequences in patients with recurrent spontaneous VT, and (4) failure of the QTc interval to be prolonged substantially is probably predictive of clinical recurrence of VT. (Texas Heart Institute Journal 1987; 14:382-388) PMID:15227294
Patel, Mehul; Rojas, Francia; Shabari, Farshad Raissi; Simpson, Leo; Cohn, William; Frazier, O H; Mallidi, Hari; Cheng, Jie; Mathuria, Nilesh
Patients undergoing catheter ablation for ventricular tachycardia (VT) may require epicardial mapping. In patients with end-stage heart failure, hybrid surgical epicardial mapping and ablation during the period of left ventricular assist device (LVAD) implantation may be considered in select patients to reduce post-LVAD ventricular tachycardia. From March 2009 to October 2012, 5 patients (4 men and 1 woman, age range 52-73 years) underwent open chest electrophysiology study and epicardial mapping for recurrent ventricular tachycardia while the heart was exposed during the period of LVAD implantation. Epicardial mapping was considered if patients had recurrent VT despite failed prior endocardial ablation and/or electrocardiogram (EKG) features of an epicardial exit. Activation and/or a substrate mapping approach were employed during all procedures. Three of 5 patients (60%) had acute procedural success. In all patients, VT was either eliminated or significantly reduced with epicardial ablation. One patient had mediastinal bleeding delaying sternal closure. During a follow-up period of 363 ± 368 days, 4 patients died due to nonarrhythmic causes. Open-chest hybrid epicardial mapping and ablation for recurrent VT is feasible and can be considered in select patients during the period of LVAD implantation. © 2015 Wiley Periodicals, Inc.
AbdelWahab, Amir; Stevenson, William; Thompson, Kara; Parkash, Ratika; Gray, Christopher; Gardner, Martin; Sapp, John
Ablation of ventricular arrhythmias (VA) can be limited by intramural substrate not amenable to endocardial or epicardial ablation. Feasibility of irrigated needle ablation has been shown, but optimal means of identifying targets is not clear. We analyzed intramural needle electrograms in relation to endocardial electrograms. Eight sequential patients (mean age, 56 years) who had failed 1 to 4 prior ablations underwent irrigated needle ablation were included. At selected sites, the needle was advanced into the myocardium. Bipolar and unipolar electrograms from the needle and catheter tip were analyzed. The needle was deployed at 75 sites with suspected intramural substrate among 2309 mapping sites. Intramural bipolar electrogram amplitude and duration correlated closely with endocardial electrograms, but were greater in amplitude and duration (1.5±1.4 versus 0.6±0.5 mV and 131±66 versus 112±51 ms; P=0.001 for both). During sinus rhythm intramural late potentials tended to be more common than endocardial late potentials (53.6% versus 35.7%; P=0.12). Intramural electrograms during VA preceded endocardial electrograms (-29±34 versus -15±21 ms; P=0.001). Irrigated needle ablation terminated VA at 12 of 28 sites with ablation during VA. Termination site needle electrograms tended to be earlier than nontermination sites (-54±37 versus -36±33 ms pre-QRS; P=0.15). Pacemapping from the needle at 19 sites matched the VA at 18 and showed stimulus to QRS of 60±51 ms. Recordings from intramural needle may be useful for selecting ablation targets during ventricular tachycardia and for substrate mapping. Further study is needed to develop methods to guide selection of optimal sites for needle deployment and ablation. © 2015 American Heart Association, Inc.
de Riva, Marta; Piers, Sebastiaan R D; Kapel, Gijs F L; Watanabe, Masaya; Venlet, Jeroen; Trines, Serge A; Schalij, Martin J; Zeppenfeld, Katja
Noninducibility is frequently used as procedural end point of ventricular tachycardia (VT) ablation after myocardial infarction. We investigated the influence of left ventricular (LV) function on the predictive value of noninducibility for VT recurrence and cardiac mortality. Ninety-one patients (82 men, 67±10 years) with post-myocardial infarction VT underwent ablation between 2009 and 2012. Fifty-nine (65%) had an LV ejection fraction (EF) >30% (mean 41±7) and 32 (35%) an LVEF≤30% (mean 20±5). Thirty patients (51%) with EF>30% and 13 (41%) with EF≤30% were noninducible after ablation (P=0.386). During a median follow-up of 23 (Q1-Q3 16-36) months, 35 patients (38%) experienced VT recurrences and 17 (18%) cardiac death. At 1 year follow-up, survival free from VT recurrence and cardiac death for patients with LVEF>30% was 80% (95% confidence interval [CI], 70-90) compared with 42% (95% CI, 33-51) for those with LVEF≤30% (P=0.001). Noninducible patients with LVEF>30% had a recurrence-free survival from cardiac death of 90% (95% CI, 71-100) compared with 65% (95% CI, 47-83) for inducible patients (P=0.015). In the subgroup of patients with LVEF≤30%, the survival free from VT recurrence and cardiac death was 31% (95% CI, 0%-60%) for noninducible compared with 39% (95% CI, 27-52) for those who remained inducible (P=0.842). Noninducible patients with moderately depressed LV function have a favorable outcome compared with patients who remained inducible after ablation. On the contrary, patients with severely depressed LV function have a poor prognosis independent of the acute procedural outcome. © 2015 American Heart Association, Inc.
Betensky, Brian P; Dong, Wei; D'Souza, Benjamin A; Zado, Erica S; Han, Yuchi; Marchlinski, Francis E
Magnetic resonance imaging (MRI) with late gadolinium enhancement is commonly performed in patients with non-ischemic LV ventricular tachycardia/ventricular premature depolarizations (non-ischemic LV-VT/VPDs) to define VT substrate prior to catheter ablation. We investigated the prevalence of abnormal voltage and VT localized to areas of the myocardium not reported to have late gadolinium enhancement (LGE) on routine pre-procedural MRI and sought to determine if quantitative MRI analysis could reduce this discordance. Patients with non-ischemic LV-VT/VPD who underwent LV endocardial mapping with VT/VPD ablation and either septal or free wall MRI-voltage discordance were studied. Electroanatomic maps were analyzed post-procedure for areas of electrogram-defined scar and VT localized to areas without reported LGE. Discordant segments were then analyzed offline using delayed signal intensity of >2 and >5 standard deviations above normal myocardium. Of 90 consecutive patients, 32 (36%) patients with septal (n = 16), free wall (n = 14) or both (n = 2) MRI-voltage + mismatch were identified. All discordant segments demonstrated unipolar voltage abnormalities with 12 patients (6 septal and 6 free wall) also showing low bipolar voltage but no LGE at signal intensity >5 standard deviations. Eleven patients (5 septum, 6 free wall) had VT localized to discordant areas. Ninety-three percent of patients in the septal group (26/48 segments) and 89% of patients in the free wall group (9/13 segments) had a concordant response established by using a signal intensity cutoff of >2 standard deviations. MRI-voltage discordance was identified in 36% of patients with non-ischemic LV-VT/VPD who underwent VT ablation. In 12% of patients, VT was targeted in areas of abnormal voltage not suggested by routine qualitative MRI. Quantitative MRI analysis using a lower signal intensity threshold increased the sensitivity for detecting areas of clinically relevant VT substrate.
Harada, Masahide; Honjo, Haruo; Yamazaki, Masatoshi; Nakagawa, Harumichi; Ishiguro, Yuko S; Okuno, Yusuke; Ashihara, Takashi; Sakuma, Ichiro; Kamiya, Kaichiro; Kodama, Itsuo
In cardiac arrest due to ventricular fibrillation (VF), moderate hypothermia (MH, 33 degrees C) has been shown to improve defibrillation success compared with normothermia (NR, 37 degrees C) and severe hypothermia (SH, 30 degrees C). The underlying mechanisms remain unclear. We hypothesized that MH might prevent reentrant excitations rotating around functional obstacles (rotors) that are responsible for the genesis of VF. In two-dimensional Langendorff-perfused rabbit hearts prepared by cryoablation (n = 13), action potential signals were recorded by a high-resolution optical mapping system. During basic stimulation (2.5-5.0 Hz), MH and SH caused significant prolongation of action potential duration and significant reduction of conduction velocity. Wavelength was unchanged at MH, whereas it was shortened significantly at SH at higher stimulation frequencies (4.0-5.0 Hz). The duration of direct current stimulation-induced ventricular tachycardia (VT)/VF was reduced dramatically at MH compared with NR and SH. The spiral wave (SW) excitations documented during VT at NR were by and large organized, whereas those during VT/VF at MH and SH were characterized by disorganization with frequent breakup. Phase maps during VT/VF at MH showed a higher incidence of SW collision (mutual annihilation or exit from the anatomical boundaries), which caused a temporal disappearance of phase singularity points (PS-0), compared with that at NR and SH. There was an inverse relation between PS-0 period in the observation area and VT/VF duration. MH data points were located in a longer PS-0 period and a shorter VT/VF duration zone compared with SH. MH causes a modification of SW dynamics, leading to an increase in the chance of SW collision in favor of self-termination of VT/VF.
Tappin, S; Brown, P; Ferasin, L
A 10-year-old female neutered boxer was presented with a five-week history of episodic collapse and melaena. Twenty-four-hour electrocardiograph (Holter) analysis revealed the collapsing episodes to coincide with episodes of paroxysmal ventricular tachycardia. Investigation of the dog's melaena revealed a gastric ulcer which was treated medically and an ileocaecal mass which was surgically excised. Histopathological examination of the mass was consistent with a neuroendocrine (carcinoid) tumour. The patient's recovery after surgery was unremarkable. At six-week follow-up, there had been no further episodes of melaena or collapse and repeat Holter analysis did not show any significant abnormalities. In this dog the gastric ulceration and paroxysmal ventricular tachycardia could be attributed to a paraneoplastic syndrome as a result of circulating vasoactive substances released by the tumour; this is supported by the evidence that all clinical signs resolved after surgical excision of the mass and the dog was clinically well 18 months after surgery.
Silva-Gburek, Jaime; Rochford, Laura; Hopkin, Robert
Fabry disease is an X-linked lysosomal storage disorder. Female carriers were long thought to be asymptomatic; however, research has revealed the opposite. Cardiac conditions are the chief causes of death in women with Fabry disease. Although ventricular tachycardia has been reported in male patients with Fabry disease, it is not thought to be a frequent finding in females. We describe the case of a 50-year-old woman in whom we used 14-day continuous electrocardiographic monitoring to identify nonsustained ventricular tachycardia, after electrocardiograms and 24-hour Holter monitoring failed to detect the arrhythmia. A permanent implantable cardioverter-defibrillator relieved the patient's symptoms. We discuss why this case supports the need for more extensive electrophysiologic evaluation in women who have Fabry disease. PMID:28100976
Dalal, Anuj K; Harding, John D; Verdino, Ralph J
Individuals searching for symptomatic relief or a potential cure are increasingly seeking and using nontraditional therapies for their various diseases. Little is known about the potential adverse effects that patients may encounter while undergoing these alternative treatments. Cesium chloride is an unregulated agent that has been reported to have antineoplastic properties. Cesium chloride is advertised as an alternative agent for many different types of cancers and can be purchased easily on the Internet. Recently, QT prolongation and polymorphic ventricular tachycardia were reported in several patients taking cesium chloride as alternative treatment for cancer. We report acquired QT prolongation and sustained monomorphic ventricular tachycardia in a patient who self-initiated and completed a course of cesium chloride as adjunctive treatment for brain cancer.
Xiong, Will W; Karam, Pascal Y; Marsh, James D; Varma, Niraj; Verdino, Ralph J; Paydak, Hakan
Differentiation between supraventricular tachycardia (SVT) and ventricular tachycardia (VT) remains a substantial clinical challenge in patients with single-chamber implantable cardioverter-defibrillators (ICDs) due to absence of visible P waves. Innovative optimization of intrathoracic electrogram (EGM) configuration will facilitate P-wave detection and rhythm differentiation during tachycardia. Innovative optimization of EGM configuration was originally performed to improve patient care. In this retrospective cohort study, we examined our database for records of 140 consecutive patients undergoing single-chamber ICD implantation. During the follow-ups of 61 included patients with optimized EGM configuration, 27 patients were identified to have VT and/or SVT. EGMs in the Can (generator) to superior vena cava (Can-SVC) configuration were compared with those conventionally from the Can to right ventricular coil (Can-RV coil) source in the same patients. In Can-SVC EGMs, the ratio of P/QRS amplitude was 14-fold higher (0.57 ± 0.08 vs. 0.04 ± 0.00, P < 0.001) compared with those in Can-RV coil EGMs during sinus rhythm. With Can-SVC configuration, the odds of atrioventricular dissociation detection in patients with VT was increased 15-fold (61.9% vs. 9.5% with Can-RV coil; odds ratio, 15.4; 95% confidence interval, 2.8 to 84.7; P = 0.0009). In patients with SVT, P-waves or retrograde P-waves were markedly more identifiable in Can-SVC configuration compared with Can-RV coil (odds ratio, 40; 95% confidence interval, 3.6 to 447.1; P = 0.0010). P-wave recognition by optimizing EGM configuration provides a novel diagnostic tool for differentiation between VT and SVT in single-chamber ICDs. A potential discrimination algorithm would provide a cost-effective approach to improving the qualitative outcomes.
Abdelwahab, Amir; Gardner, Martin; Parkash, Ratika; Gray, Christopher; Sapp, John
Catheter ablation of VT in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) is often challenging, frequently requiring multiple or epicardial ablation procedures; TMEM43 gene mutations typically cause aggressive disease. We sought to compare VT ablation outcomes for ARVC patients with and without TMEM43 mutations. Patients with prior ablation for ARVC-related VT were reviewed. Demographic, procedural and follow-up data were reviewed retrospectively. Patients with confirmed TMEM43 gene mutations were compared to those with other known mutations or who had no known mutations. Thirteen patients (10 male, mean age 49±14 yrs) underwent 29 ablation procedures (Median 2 procedures/patient, range 1-6) with a median of 4 targeted VTs/patient (range 1 -9). They were followed for a mean duration of 7.3±4.2 years. Gene mutations included TMEM43 (n = 5), PKP2 (n = 2), DSG2 (n = 2), unidentifiable (n = 4). TMEM patients showed more biventricular involvement compared to Non-TMEM patients (80% vs. 12.5%, p = 0.032), more inducible VTs during their ablation procedures (mean VTs/patient: 5.8±3 vs. 2.6±1, p = 0.021). Acute and long-term procedural outcomes did not show a significant difference between the two groups, however TMEM patients had worse composite endpoint of death or transplantation (60% vs. 0, p = 0.035; Log-Rank p = 0.013). TMEM43 mutation patients were more likely to have biventricular arrhythmogenic substrate and more inducible VTs at EP study. Despite comparable acute VT ablation outcomes, long-term prognosis is unfavorable. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Skoda, Jan; Arya, Arash; Garcia, Fermin; Gerstenfeld, Edward; Marchlinski, Francis; Hindricks, Gerhard; Miller, John; Petru, Jan; Sediva, Lucie; Sha, Qun; Janotka, Marek; Chovanec, Milan; Waldauf, Petr; Neuzil, Petr; Reddy, Vivek Y
Catheter ablation is an effective treatment of scar-related ventricular tachycardia (VT), but the overall complexity of the procedure has precluded its widespread use. Remote magnetic navigation (RMN) has been shown to facilitate cardiac mapping and ablation of VT in a retrospective series. STOP-VT is the first multicenter, prospective, single-arm and single-procedure study evaluating RMN-based mapping and ablation of post-infarction VT. Patients with documented VT and prior MI, in whom an ICD was implanted either for primary or secondary prevention, were recruited from four EU and US centers. Either a transseptal (48 patients) or transaortic (5 patients) approach was employed to gain access for ventricular endocardial mapping/ablation during VT (entrainment mapping, activation mapping) and/or substrate mapping in sinus rhythm (elimination of fractionated/late potentials, variable extent of substrate modification) with RMN and irrigated RF ablation. The primary endpoints were as follows: (i) non-inducibility of the target VT or any other sustained VT; (ii) elimination of sustained VT/VF during ICD follow-up of up to 12 months. The cohort included 53 consecutive patients (median age 67 years, 49 men, median LVEF 31%). One hemodynamically unstable patient was excluded at the onset of mapping. Inducibility of sustained VT was achieved an average of 2.2 times per patient (1-8), with mean tachycardia cycle length (TCL) 374 milliseconds (179-510). Mean total procedure and fluoroscopy times were 223 minutes and 8.7 minutes, respectively; mean cumulative fluoroscopy time during mapping and ablation was 0.95 minutes; maximum power averaged 42.3 W with nominal saline 30 cc/min irrigation; mean cumulative RF time was 38 minutes. Non-inducibility of the target VT was achieved in 49/52 patients (94.2%) and non-inducibility of any VT was achieved in 38/52 patients (73.1%). A combination of RMN and manual ablation was performed in two patients, rendering one non-inducible. During
Volosin, Kent; Stadler, Robert W; Wyszynski, Ryan; Kirchhof, Paulus
Implantable loop recorders (ILRs) are valuable for diagnosing arrhythmias. We evaluated tachycardia detection performance of the Medtronic Reveal(®) ILR with FullView™ Software. The rate of occurrence of tachycardia detection [supraventricular tachycardia, ventricular tachycardia (VT), and ventricular fibrillation (VF)] and the percentage of appropriately detected tachycardias were determined from all 2190 ILR patients that transmitted to CareLink over a 4-month period (total follow-up = 135.6 patient-years). All 1909 tachycardia episodes were reviewed. Episodes with actual heart rate above the programmed tachycardia detection rate were classified as appropriate. Sensitivity to detect true ventricular arrhythmias was assessed in another group of 215 patients undergoing implantable cardioverter defibrillator (ICD) implant testing. Skin electrodes represented ILR electrodes. Induced VF (404 episodes) and VT (93 episodes) were processed by an emulation of FullView Software. Generalized estimation equation analysis adjusted for multiple episodes per patient. In the CareLink cohort, 68.7% (63.9% adjusted) of detected episodes had tachycardia above the detection rate. Of 1642 episodes detected in the VT zone (12.1 episodes/patient-year), 78.8% (79.0% adjusted) had tachycardia above the detection rate. Of 267 episodes detected in the fast VT zone (1.9 episodes/patient-year), 6.7% (9.4% adjusted) had tachycardia above the detection rate. Twelve true VT/VF episodes were observed in 10 patients. In the ICD patient cohort, 95.9% (96.5% adjusted) of induced VT/VF segments were correctly detected at nominal rate cutoffs. When VT detection was set to 130 b.p.m. (to include the slowest VT), 99.0% (99.3% adjusted) were correctly detected. The majority (63.9%) of detected tachycardias contained true tachycardia. Sensitivity to detect induced VT/VF was 99.3%.
Berisso, M Z; Molini, D; Camerini, A; Mela, G S; Vecchio, C
Programmed ventricular stimulation performed early after acute myocardial infarction allows to identify patients at risk of sudden death and sustained ventricular tachycardia with high degree of predictive accuracy. This procedure, however, because of its invasive nature, is not desirable as a screening test for large numbers of patients. Therefore, it should be performed on a smaller group of postinfarction patients preselected on the basis of noninvasive testing. The aim of the present study was to identify, early after acute myocardial infarction, any procedure among noninvasive testing, able to selected with the highest sensitivity patients at risk of sudden death and sustained ventricular tachycardia to submit to programmed ventricular stimulation. Two hundred and sixty four consecutive patients with recent myocardial infarction were evaluated and followed during a period of 12 months. In each patient 48 epidemiological, clinical and laboratory variables were evaluated. Laboratory variables were acquired between the 7th and the 12th day after the acute event. Multiple linear regression analysis showed that only Killip class, the number of ventricular premature depolarizations per hour and the presence of ventricular late potentials were significantly and independently related to the occurrence of sudden death and sustained ventricular tachycardia (F = 18.7; p < 0.00001). Combinations of these variables, determined at cut off levels best discriminating two subgroups of patients at different risk of the end-point events, proved to be able to accurately predict the outcome of our patients. The presence of at least one of the following conditions: Killip class > or = 2, ventricular premature depolarizations > or = 30 per hour, ventricular late potentials allowed to identify a first subgroup of patients at risk with a sensitivity of 100% (p = 0.00007), whereas the presence, at the same time, of all the above mentioned parameters allowed to identify a second
Lujan, Heidi L.; Palani, Gurunanthan; Zhang, Lijie
The Cardiac Arrhythmia Suppression Trial demonstrated that antiarrhythmic drugs not only fail to prevent sudden cardiac death, but actually increase overall mortality. These findings have been confirmed in additional trials. The “proarrhythmic” effects of most currently available antiarrhythmic drugs makes it essential that we investigate novel strategies for the prevention of sudden cardiac death. Targeted ablation of cardiac sympathetic neurons may become a therapeutic option by reducing sympathetic activity. Thus cholera toxin B subunit (CTB) conjugated to saporin (a ribosomal inactivating protein that binds to and inactivates ribosomes; CTB-SAP) was injected into both stellate ganglia to test the hypothesis that targeted ablation of cardiac sympathetic neurons reduces the susceptibility to ischemia-induced, sustained ventricular tachycardia in conscious rats. Rats were randomly divided into three groups: 1) control (no injection); 2) bilateral stellate ganglia injection of CTB; and 3) bilateral stellate ganglia injection of CTB-SAP. CTB-SAP rats had a reduced susceptibility to ischemia-induced, sustained ventricular tachycardia. Associated with the reduced susceptibility to ventricular arrhythmias were a reduced number of stained neurons in the stellate ganglia and spinal cord (segments T1-T4), as well as a reduced left ventricular norepinephrine content and sympathetic innervation density. Thus CTB-SAP retrogradely transported from the stellate ganglia is effective at ablating cardiac sympathetic neurons and reducing the susceptibility to ventricular arrhythmias. PMID:20173045
Sapp, John L; Beeckler, Christopher; Pike, Robert; Parkash, Ratika; Gray, Christopher J; Zeppenfeld, Katja; Kuriachan, Vikas; Stevenson, William G
Ablation of ventricular tachycardia (VT) is sometimes unsuccessful when ablation lesions are of insufficient depth to reach arrhythmogenic substrate. We report the initial experience with the use of a catheter with an extendable/retractable irrigated needle at the tip capable of intramyocardial mapping and ablation. Sequential consenting patients with recurrent VT underwent ablation with the use of a needle-tipped catheter. At target sites, the needle was advanced 7 to 9 mm into the myocardium, permitting pacing and recording. Infusion of saline/iodinated contrast mixture excluded perforation and ensured intramyocardial deployment. Further infusion was delivered before and during temperature-controlled radiofrequency energy delivery through the needle. All 8 patients included (6 male; mean age, 54) with a mean left ventricular ejection fraction of 29% were refractory to multiple antiarrhythmic drugs, and 1 to 4 previous catheter ablation attempts (epicardial in 4) had failed. Patients had 1 to 7 (median, 2) VTs present or inducible; 2 were incessant. Some intramyocardial VT mapping was possible in 7 patients. A mean of 22 (limits, 3-48) needle ablation lesions were applied in 8 patients. All patients had at least 1 VT terminated or rendered noninducible. During a median of 12 months follow-up, 4 patients were free of recurrent VT, and 3 patients were improved, but had new VTs occur at some point during follow-up. Two died of the progression of preexisting heart failure without recurrent VT. Complications included tamponade in 1 patient and heart block in 2 patients. Intramyocardial infusion-needle catheter ablation is feasible and permits control of some VTs that have been refractory to conventional catheter ablation therapy, warranting further study.
Li, Shi-Jun; Wang, Tao; Wang, Lin; Pang, Zhan-Qi; Ma, Ben; Li, Ya-Wen; Yang, Jian; Dong, He
Pheochromocytomas are neuroendocrine tumors, and its cardiac involvement may include transient myocardial dysfunction, acute coronary syndrome (ACS), and even ventricular arrhythmias.A patient was referred for evaluation of stuttering chest pain, and his electrocardiogram showed T-wave inversion over leads V1 to V4. Coronary angiography showed 90% stenosis in the mid-left anterior descending coronary artery (LAD), which was stented. Five days later, the patient had ventricular tachycardia, and severe hypertension, remarkable blood pressure fluctuation between 224/76 and 70/50 mm Hg. The patient felt abdominal pain and his abdominal ultrasound showed suspicious right adrenal gland tumor. Enhanced computed tomography of adrenal gland conformed that there was a tumor in right adrenal gland accompanied by an upset level of aldosterone.The tumor was removed by laparoscope, and the pathological examination showed pheochromocytoma. After the surgery, the blood pressure turned normal gradually. There was no T-wave inversion in lead V1-V4. Our case illustrates a rare pheochromocytoma presentation with a VT and resembling ACS. In our case, the serious stenosis in the mid of LAD could be explained by worsen the clinical course of myocardial ischemia or severe coronary vasospasm by the excessive amounts of catecholamines released from the tumor. Coronary vasospasm was possible because he had no classic coronary risk factors (e.g. family history and smoking habit, essential hypertension, hyperglycemia and abnormal serum lipoprotein, high body mass index). Thus, pheochromocytoma was missed until he revealed the association of his symptoms with abdominalgia.As phaeochromocytomas that present with cardiovascular complications can be fatal, it is necessary to screen for the disease when patients present with symptoms indicating catecholamine excess.
Tschabrunn, Cory M.; Roujol, Sébastien; Nezafat, Reza; Faulkner-Jones, Beverly; Buxton, Alfred E.; Josephson, Mark E.; Anter, Elad
BACKGROUND Human ventricular tachycardia (VT) after myocardial infarction usually occurs because of subendocardial reentrant circuits originating in scar tissue that borders surviving myocardial bundles. Several preclinical large animal models have been used to further study postinfarct reentrant VT, but with varied experimental methodologies and limited evaluation of the underlying substrate or induced arrhythmia mechanism. OBJECTIVE We aimed to develop and characterize a swine model of scar-related reentrant VT. METHODS Thirty-five Yorkshire swine underwent 180-minute occlusion of the left anterior descending coronary artery. Thirty-one animals (89%) survived the 6–8-week survival period. These animals underwent cardiac magnetic resonance imaging followed by electrophysiology study, detailed electroanatomic mapping, and histopathological analysis. RESULTS Left ventricular (LV) ejection fraction measured using CMR imaging was 36% ± 6.6% with anteroseptal wall motion abnormality and late gadolinium enhancement across 12.5% ± 4.1% of the LV surface area. Low voltage measured using endocardial electroanatomic mapping encompassed 11.1% ± 3.5% of the LV surface area (bipolar voltage ≤1.5 mV) with anterior, anteroseptal, and anterolateral involvement. Reentrant circuits mapped were largely determined by functional rather than fix anatomical barriers, consistent with “pseudo-block” due to anisotropic conduction. Sustained monomorphic VT was induced in 28 of 31 swine (90%) (67 VTs; 2.4 ± 1.1; range 1–4) and characterized as reentry. VT circuits were subendocardial, with an arrhythmogenic substrate characterized by transmural anterior scar with varying degrees of fibrosis and myocardial fiber disarray on the septal and lateral borders. CONCLUSION This is a well-characterized swine model of scar-related subendocardial reentrant VT. This model can serve as the basis for further investigation in the physiology and therapeutics of humanlike postinfarction
Baker, L C; London, B; Choi, B R; Koren, G; Salama, G
The heterogeneous distribution of ion channels in ventricular muscle gives rise to spatial variations in action potential (AP) duration (APD) and contributes to the repolarization sequence in healthy hearts. It has been proposed that enhanced dispersion of repolarization may underlie arrhythmias in diseases with markedly different causes. We engineered dominant negative transgenic mice that have prolonged QT intervals and arrhythmias due to the loss of a slowly inactivating K(+) current. Optical techniques are now applied to map APs and investigate the mechanisms underlying these arrhythmias. Hearts from transgenic and control mice were isolated, perfused, stained with di-4-ANEPPS, and paced at multiple sites to optically map APs, activation, and repolarization sequences at baseline and during arrhythmias. Transgenic hearts exhibited a 2-fold prolongation of APD, less shortening (8% versus 40%) of APDs with decreasing cycle length, altered restitution kinetics, and greater gradients of refractoriness from apex to base compared with control hearts. A premature impulse applied at the apex of transgenic hearts produced sustained reentrant ventricular tachycardia (n=14 of 15 hearts) that did not occur with stimulation at the base (n=8) or at any location in control hearts (n=12). In transgenic hearts, premature impulses initiated reentry by encountering functional lines of conduction block caused by enhanced dispersion of refractoriness. Reentrant VT had stable (>30 minutes) alternating long/short APDs associated with long/short cycle lengths and T wave alternans. Thus, optical mapping of genetically engineered mice may help elucidate some electrophysiological mechanisms that underlie arrhythmias and sudden death in human cardiac disorders.
Tzou, Wendy S; Frankel, David S; Hegeman, Timothy; Supple, Gregory E; Garcia, Fermin C; Santangeli, Pasquale; Katz, David F; Sauer, William H; Marchlinski, Francis E
Radiofrequency ablation of multiple or unmappable ventricular tachycardias (VTs) remains a challenge with unclear end points. We present our experience with a new strategy isolating core elements of VT circuits. Patients with structural heart disease presenting for VT radiofrequency ablation at 2 centers were included. Strategy involved entrainment/activation mapping if VT was hemodynamically stable, and voltage mapping with electrogram analysis and pacemapping. Core isolation (CI) was performed incorporating putative isthmus and early exit site(s) based on standard criteria. If VT was noninducible, the dense scar (<0.5 mV) region was isolated. Successful CI was defined by exit block (20 mA at 2 ms) within the isolated region. VT inducibility was also assessed. Forty-four patients were included (mean age, 63; 95% male; 73% ischemic cardiomyopathy; mean left ventricular ejection fraction, 31%; 68% with multiple unstable VTs [mean, 3+2]). CI area was 11+12 versus 55+40 cm(2) total scar area. Additional substrate modification was performed in 27 (61%), and epicardial radiofrequency ablation was performed in 4 (9%) patients. CI was achieved in 37 (84%) and led to better VT-free survival (log rank P=0.013). CI is a novel strategy with a discrete and measurable end point beyond VT inducibility to treat patients with multiple or unmappable VTs. The CI region can be selected based on standard characterization of suspected VT isthmus surrogates thus limiting ablation target size. Exit block within the isolated area is achievable in most and may further improve long-term success. © 2015 American Heart Association, Inc.
Wang, Jing; Hua, Wei; Zhu, Jun; Yang, Yan-Min; Wang, Fang-Zheng; Pu, Jie-Lin; Chen, Ke-Ping; Zhang, Shu
Ventricular tachycardia (VT) and ventricular fibrillation are the main reasons causing sudden cardiac death. This study aimed to investigate the effects of nifekalant hydrochloride (NIF) on QT dispersion (QTd) in treating VT. A total of 16 consecutive patients suffered sustained VT was included and then randomly divided into two groups according to the administration duration of NIF. In long-time group (group L), patients were injected with NIF continuously for at least 12 hours after a bolus dose. The patients in short-time group (group S) were injected with NIF just for 1 hour. There were 7 of all 10 episodes of VT which were terminated by NIF, including 4 episodes in group L were stopped over 1 hour after continuous infusion of NIF. One patient suffered from torsade de pointes. Electrocardiography analysis indicated that QTd was significantly decreased 12 hours after stopping of infusing NIF compared with that when VT stopped ((45.4 +/- 22.1) ms vs. (73.4 +/- 33.2) ms, P < 0.01), and the corrected QTd (QTcd) decreased too ((47.8 +/- 22.9) ms vs. (78.3 +/- 36.5) ms, P < 0.01). There was a positive correlation between the increase in QTd and dose of administrating NIF (P < 0.01), so was QTcd (P < 0.01). More administration of NIF indicates higher terminating rate of VT and more QTd prolongation. However, the safety is acceptable if several important issues were noticed in using NIF, such as serum potassium concentration, stopping side-effect related agents, and carefully observing clinical responses.
Weissler-Snir, Adaya; Chan, Raymond H; Adler, Arnon; Care, Melanie; Chauhan, Vijay; Gollob, Michael H; Ziv-Baran, Tomer; Fourey, Dana; Hindieh, Waseem; Rakowski, Harry; Spears, Danna A
Nonsustained ventricular tachycardia (NSVT), defined as ≥3 consecutive ventricular beats at ≥120 beats/min lasting <30 seconds, is an independent predictor of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HC). Current guidelines recommend 24- to 48-hour Holter monitoring as part of SCD risk stratification. We sought to assess the difference in diagnostic yield of 14-day Holter monitoring compared to 24-48 hours for the detection of NSVT and to assess the prevalence and characteristics of NSVT in patients with HC with prolonged monitoring. We retrospectively analyzed the 14-day Holter monitors of 77 patients with HC from May 2014 to March 2016. Number of episodes and maximal length and rate on each day were recorded. NSVT was detected in 75.3% of patients during 14-day Holter monitoring. The median number of runs was 2 (range 0 to 26 runs). The median number of beats of the longest run was 10.5 (range 3 to 68 beats) with a mean maximum rate of 159.5 ± 20.8.4 beats/min (range 102 to 203 beats/min). First episodes of NSVT were detected throughout the 14 days, with only 22.5% and 44.8% of the episodes captured within the first 24 and 48 hours of monitoring, respectively. In conclusion, prolonged Holter monitoring revealed ≥1 episode of NSVT in 75% of patients with HC of which <50% were detected within the first 48 hours. Hence, prolonged Holter monitoring may be superior for SCD risk stratification in HC. However, the high prevalence of NSVT in this population may limit its utility in evaluating the risk for SCD of the individual patient. Copyright © 2016 Elsevier Inc. All rights reserved.
Sasaki, Takeshi; Miller, Christopher F; Hansford, Rozann; Zipunnikov, Vadim; Zviman, Menekhem M; Marine, Joseph E; Spragg, David; Cheng, Alan; Tandri, Harikrishna; Sinha, Sunil; Kolandaivelu, Aravindan; Zimmerman, Stefan L; Bluemke, David A; Tomaselli, Gordon F; Berger, Ronald D; Halperin, Henry R; Calkins, Hugh; Nazarian, Saman
The association of local electrogram features with scar morphology and distribution in nonischemic cardiomyopathy has not been investigated. We aimed to quantify the association of scar on late gadolinium-enhanced cardiac magnetic resonance with local electrograms and ventricular tachycardia circuit sites in patients with nonischemic cardiomyopathy. Fifteen patients with nonischemic cardiomyopathy underwent late gadolinium-enhanced cardiac magnetic resonance before ventricular tachycardia ablation. The transmural extent and intramural types (endocardial, midwall, epicardial, patchy, transmural) of scar were measured in late gadolinium-enhanced cardiac magnetic resonance short-axis planes. Electroanatomic map points were registered to late gadolinium-enhanced cardiac magnetic resonance images. Myocardial wall thickness, scar transmurality, and intramural scar types were independently associated with electrogram amplitude, duration, and deflections in linear mixed-effects multivariable models, clustered by patient. Fractionated and isolated potentials were more likely to be observed in regions with higher scar transmurality (P<0.0001 by ANOVA) and in regions with patchy scar (versus endocardial, midwall, epicardial scar; P<0.05 by ANOVA). Most ventricular tachycardia circuit sites were located in scar with >25% scar transmurality. Electrogram features are associated with scar morphology and distribution in patients with nonischemic cardiomyopathy. Previous knowledge of electrogram image associations may optimize procedural strategies including the decision to obtain epicardial access.
Della Bella, Paolo; Bisceglia, Caterina; Tung, Roderick
Substrate-based approaches for ablation of unmappable ventricular tachycardia (VT) are strictly dependent on high-density mapping of the scar. Ultra-high-density mapping with multielectrode catheters facilitates an accurate and faster definition of sites critical for re-entry, due to the possibility of simultaneous recordings of local potential from different pairs of electrodes. Multipolar catheters can be advanced to map the endocardial or the epicardial surface. A strong correlation between the scar area determined by electroanatomical mapping and the histopathological scar size has been demonstrated. A double-transeptal technique allows for an accurate definition of target sites. The complex scar architecture has been investigated by ultra-high-density mapping, let the identification of islets of heterogeneity where electrograms adjacent to the preserved myocardium have an higher incidence of late potentials. Pacing manoeuvres can easily be performed from any pair of electrode, to demonstrate the involvement of late potentials into the VT circuit. This strategy allows for a clear-cut validation of late potential abolishment, and may offer advantages to shorten procedural and fluoroscopy times. Large series are necessary to definitively assess the potential role of multielectrode mapping as a guide for the substrate ablation approach in post-myocardial infarction VT patients.
Bodegas, A; Arana, J; Rumoroso, J R; Rodrigo, D; Barrenetxea, J I
To evaluate the cardiac mortality in patients suffering from a first episode of sustained monomorphic ventricular tachycardia (SMVT). 100 patients less than 75 years old were evaluated during a 50-month follow-up period. Patients were classified into four groups: myocardial infarction, dilated cardiomyopathy, normal heart and miscellany. Seventeen patients underwent a cardioverter-defibrillator implantation, two heart transplant, three aneurysmectomy and 10 other types of cardiac surgical proceedings. Patients with a left ventricle ejection fraction (EF)> or =50% presented a cardiac mortality of 5% compared with 38% of those with EF<50%. Etiology of underlying cardiomyopathy with an EF> or =50% was associated with a cardiac mortality of 5% (normal heart), 5% (myocardial infarction) and 9% (miscellany) compared to those with EF<50%: 33% (dilated cardiomyopathy) and 40% (myocardial infarction). Patients who experienced syncope during the first episode of SMVT showed a cardiac mortality of 31% compared to those 14% (P < 0.05) who did not experience. Patients with syncope, myocardial infarction and EF<50% showed a cardiac mortality of 68%. The present study shows that survival after the first episode of SMVT is closely related to EF and the existence of syncope. Patients with myocardial infarction and EF<50% had a worse prognosis when the site was the inferior wall.
Tschabrunn, Cory M; Haqqani, Haris M; Zado, Erica S; Marchlinski, Francis E
Epicardial mapping and ablation of ventricular tachycardia (VT) has been increasingly performed. Occasionally additional ablation is necessary, requiring repeat percutaneous access to the pericardial space. We studied 30 consecutive patients who required a repeat epicardial procedure. We specifically examined the success and safety of repeat percutaneous pericardial access as well as the ability to map and ablate epicardial VT targets. Percutaneous pericardial access at a median of 110 days after the last procedure was successful in all 30 patients. Significant adhesions interfering with catheter mapping were encountered in 7 patients (23%); 6 had received intrapericardial triamcinolone acetate (IPTA) with prior procedures. Using blunt dissection with a deflected ablation catheter and a steerable sheath, adhesions were divided allowing for complete catheter mapping in 5 patients with areas of dense adherence compartmentalizing the pericardium in 1 patient and precluding ablation over previously targeted ablation site in the second. Targeted VT noninducibility was achieved in 27 (90%) patients including 7 patients with adhesions. No direct complications related to pericardial access or adhesions disruption occurred. One periprocedural death occurred from refractory cardiogenic shock in patient with LV ejection fraction of 10%. Another patient developed asymptomatic positive Haemophilus influenzae pericardial fluid cultures identified at second procedure, which was successfully treated. Repeat access can be obtained after prior epicardial ablation. Adhesions from prior procedures may limit mapping, but can usually be disrupted mechanically and allow for ablation of recurrent VT. IPTA may not completely prevent adhesions. © 2012 Wiley Periodicals, Inc.
Gabriels, James; Wu, Michael; Rosen, Lisa; Patel, Apoor; Goldner, Bruce
Permanent pacemaker electrograms record a variety of arrhythmias, including nonsustained ventricular tachycardia (NSVT). Little has been reported regarding incidence and clinical significance of NSVT in pacemaker patients after long-term monitoring. Records from all patients implanted with Medtronic pacemakers (Medtronic, Minneapolis, MN, USA) at a single institution from January 1, 2009 to February 27, 2012 were reviewed. Demographic characteristics, imaging studies, pacemaker interrogations, and the Social Security Death Index were examined in patients older than 18 years of age who had ≥ 2 follow-up device interrogations. A total of 262 patients with an ejection fraction (EF) >40% were included in the final analysis with a mean follow-up of 29.2 months. Of these patients, 83.2% (n = 218) had hypertension (HTN) and 45.4% (n = 119) had NSVT. Among patients with an EF ≥ 55%, hypertensive patients had a NSVT burden 2.46 times greater than normotensive patients (incidence rate ratio: 2.46, 95% confidence interval: 1.10-5.50; P < 0.028). NSVT was not associated with increased mortality (P < 0.1229). In this cohort of patients, there was a high prevalence of HTN and while hypertensive subjects had a significantly higher NSVT burden, NSVT was not associated with an increased mortality. © 2016 Wiley Periodicals, Inc.
Al-Khatib, Sana M; Daubert, James P; Anstrom, Kevin J; Daoud, Emile G; Gonzalez, Mario; Saba, Samir; Jackson, Kevin P; Reece, Tammy; Gu, Joan; Pokorney, Sean D; Granger, Christopher B; Hess, Paul L; Mark, Daniel B; Stevenson, William G
We conducted this pilot randomized clinical trial to determine the feasibility of a large clinical trial aimed at testing whether early use of catheter ablation of ventricular tachycardia (VT) is superior to antiarrhythmic medications at reducing mortality. Patients were enrolled at 4 sites if they had ischemic heart disease, an implantable cardioverter defibrillator (ICD), and received ≥1 ICD shock or ≥3 antitachycardia pacing therapies for VT. Patients were randomized to 2 arms: (1) antiarrhythmic medication (n = 14) and (2) catheter ablation (n = 13); patients were followed at 3 and 6 months. Endpoints included recurrent VT, time to first ICD therapy for VT, and death. Of 243 screened patients, 27 were enrolled. Main reasons for screen failures were: (1) patient was already on an antiarrhythmic medication (88 [41%]), (2) VT due to a reversible cause (23 [11%]), and (3) incessant VT (20 [9%]). Fourteen patients had recurrent VT, 8 (62%) in the ablation arm and 6 (43%) in the antiarrhythmic medication arm. Median time to recurrent VT was 75 days (25th, 75th: 51, 89) in the ablation arm and 57 days (30, 145) in the antiarrhythmic arm. Four patients died, 2 in each arm. This clinical trial shows that most patients in clinical practice have already failed antiarrhythmic drug therapy before catheter ablation is considered, and the VT recurrence rates and death in these patients are high. For a large clinical trial to be feasible, factors limiting early consideration of catheter ablation need to be identified and addressed. © 2014 Wiley Periodicals, Inc.
Tokuda, Michifumi; Kojodjojo, Pipin; Tung, Stanley; Tedrow, Usha B.; Nof, Eyal; Inada, Keiichi; Koplan, Bruce A.; Michaud, Gregory F.; John, Roy M.; Epstein, Laurence M.; Stevenson, William G.
Background Acute end points of catheter ablation for ventricular tachycardia (VT) remain incompletely defined. The aim of this study is to identify causes for failure in patients with structural heart disease and to assess the relation of this acute outcome to longer‐term management and outcomes. Methods and Results From 2002 to 2010, 518 consecutive patients (84% male, 62±14 years) with structural heart disease underwent a first ablation procedure for sustained VT at our institution. Acute ablation failure was defined as persistent inducibility of a clinical VT. Acute ablation failure was seen in 52 (10%) patients. Causes for failure were: intramural free wall VT in 13 (25%), deep septal VT in 9 (17%), decision not to ablate due to proximity to the bundle of His, left phrenic nerve, or a coronary artery in 3 (6%), and endocardial ablation failure with inability or decision not to attempt to access the epicardium in 27 (52%) patients. In multivariable analysis, ablation failure was an independent predictor of mortality (hazard ratio 2.010, 95% CI 1.147 to 3.239, P=0.004) and VT recurrence (hazard ratio 2.385, 95% CI 1.642 to 3.466, P<0.001). Conclusions With endocardial or epicardial ablation, or both, acute ablation failure was seen in 10% of patients, largely due to anatomic factors. Persistence of a clinical VT is associated with recurrence and comparatively higher mortality. PMID:23727700
Relan, J; Chinchapatnam, P; Sermesant, M; Rhode, K; Delingette, H; Razavi, R; Ayache, N
Despite recent efforts in cardiac electrophysiology modelling, there is still a strong need to make macroscopic models usable in planning and assistance of the clinical procedures. This requires model personalisation i.e. estimation of patient-specific model parameters and computations compatible with clinical constraints. Fast macroscopic models allow a quick estimation of the tissue conductivity, but are often unreliable in prediction of arrhythmias. On the other side, complex biophysical models are quite expensive for the tissue conductivity estimation, but are well suited for arrhythmia predictions. Here we present a coupled personalisation framework, which combines the benefits of the two models. A fast Eikonal (EK) model is used to estimate the conductivity parameters, which are then used to set the parameters of a biophysical model, the Mitchell-Schaeffer (MS) model. Additional parameters related to Action Potential Duration (APD) and APD restitution curves for the tissue are estimated for the MS model. This framework is applied to a clinical dataset provided with an hybrid X-Ray/MR imaging on an ischemic patient. This personalised MS Model is then used for in silico simulation of clinical Ventricular Tachycardia (VT) stimulation protocol to predict the induction of VT. This proof of concept opens up possibilities of using VT induction modelling directly in the intervention room, in order to plan the radio-frequency ablation lines.
Marchlinski, Francis E; Haffajee, Charles I; Beshai, John F; Dickfeld, Timm-Michael L; Gonzalez, Mario D; Hsia, Henry H; Schuger, Claudio D; Beckman, Karen J; Bogun, Frank M; Pollak, Scott J; Bhandari, Anil K
Radiofrequency catheter ablation is used to treat recurrent ventricular tachycardia (VT). This study evaluated long-term safety and effectiveness of radiofrequency catheter ablation using an open-irrigated catheter. Patients with sustained monomorphic ventricular tachycardia associated with coronary disease were analyzed for cardiovascular-specific adverse events within 7 days of treatment, hospitalization duration, 6-month sustained monomorphic ventricular tachycardia recurrence, quality of life measured by the Hospital Anxiety and Depression Scale, long-term (1-, 2-, and 3-year) survival, symptomatic VT control, and amiodarone use. Overall, 249 patients, mean age 67.4 years, were enrolled. The cardiovascular-specific adverse events rate was 3.9% (9 of 233) with no strokes. Noninducibility of targeted VT was achieved in 75.9% of patients. Post-ablation median hospitalization was 2 days. At 6 months, 62.0% (114 of 184) of patients had no sustained monomorphic ventricular tachycardia recurrence; the proportion of patients with implantable cardioverter-defibrillator shocks decreased from 81.2% to 26.8% (p < 0.0001); the frequency of VT in implantable cardioverter-defibrillator patients with recurrences was reduced by ≥50% in 63.8% of patients; and the proportion with normal Hospital Anxiety and Depression Scale scores increased from 48.8% to 69.1% (p < 0.001). Patient-reported VT remained steady for 1, 2, and 3 years at 22.7%, 29.8%, and 24.1%, respectively. Amiodarone use and hospitalization decreased from 55% and 77.2% pre-ablation to 23.3% and 30.7%, 18.5% and 36.7%, 17.7% and 31.3% at 1, 2, and 3 years, respectively. Radiofrequency catheter ablation reduced implantable cardioverter-defibrillator shocks and VT episodes and improved quality of life at 6 months. A steady 3-year nonrecurrence rate with reduced amiodarone use and hospitalizations indicate improved long-term outcomes. (NaviStar ThermoCool Catheter for Endocardial RF Ablation in Patients With
Wagshall, Alan; Abela, George S; Maheshwari, Alok; Gupta, Anoop; Bowden, Russell; Huang, S K Stephen
Nd:YAG laser energy has been proposed as an alternative to radiofrequency energy for ablation of ventricular tachycardia (VT) associated with coronary artery disease (CAD) in an effort to increase lesion size and success rates. However, issues of catheter design to maintain flexibility and ensure adequate tissue contact have hindered development of laser catheters. We developed and tested a prototype 8 Fr. steerable catheter with a flexible and extendible tip (designed to ensure tissue contact and efficient ventricular mapping), which projects the laser beam through a side port containing a lens-tipped optical fiber that rests against the endocardial surface. The catheter has a channel for simultaneous saline irrigation to displace the interceding blood and discharge a laser beam between two electrodes for bipolar mapping and a thermocouple for temperature monitoring. The catheter was tested on bench top using the epicardial surface of freshly slaughtered bovine hearts and in vivo using six anaesthetized closed-chest sheep. In vitro experiments demonstrated that lesion size increased linearly with applied power up to 40 watts. When compared to radio frequency, laser energy penetrated more deeply into the myocardium. In the in vivo studies, using increasing powers of up to 40 watts for application times of 60 to 120 seconds created circular or elliptical lesions with surface dimensions up to 12 mm x 12 mm and depth of 9 mm (full LV wall thickness with a mean lesion diameter of 9.9 +/- 5.2 mm and depth 5.8 +/- 3.2 mm). Most lesions, 16 total in both right and left ventricular walls were transmural or near transmural in thickness. Lesions demonstrated coagulation necrosis with smooth well-demarcated borders. No animal suffered cardiac perforation, hypotension, hemopericardium, damage to cardiac valves, or cavitation effect from any of the ablations. Runs of VT were seen during energy application at the highest laser outputs in two animals. In conclusion, this catheter
Aryana, Arash; Gearoid O'Neill, P; Gregory, David; Scotti, Dennis; Bailey, Sean; Brunton, Scott; Chang, Michael; d'Avila, André
Hemodynamic support using percutaneous left ventricular assist devices (pLVADs) during catheter mapping and ablation of unstable ventricular tachycardia (VT) can provide effective end-organ perfusion. However, its effect on procedural and clinical outcomes remains unclear. To retrospectively evaluate the procedural and clinical outcomes after the catheter ablation of unstable VT with and without pLVAD support. Sixty-eight consecutive unstable, scar-mediated endocardial and/or epicardial VT ablation procedures performed in 63 patients were evaluated. During VT mapping and ablation, hemodynamic support was provided by intravenous inotropes with a pLVAD (n = 34) or without a pLVAD (control; n = 34). Baseline patient characteristics were similar. VT was sustained longer with a pLVAD (27.4 ± 18.7 minutes) than without a pLVAD (5.3 ± 3.6 minutes) (P < .001). A higher number of VTs were terminated during ablation with a pLVAD (1.2 ± 0.9 per procedure) than without a pLVAD (0.4 ± 0.6 per procedure) (P < .001). Total radiofrequency ablation time was shorter with a pLVAD (53 ± 30 minutes) than without a pLVAD (68 ± 33 minutes) (P = .022), but with similar procedural success rates (71% for both pLVAD and control groups; P = 1.000). Although during 19 ± 12 months of follow-up VT recurrence did not differ between pLVAD (26%) and control (41%) groups (P = .305), the composite end point of 30-day rehospitalization, redo-VT ablation, recurrent implantable cardioverter-defibrillator therapies, and 3-month mortality was lower with a pLVAD (12%) than without a pLVAD (35%) (P = .043). In this nonrandomized retrospective study, catheter ablation of unstable VT supported by a pLVAD was associated with shorter ablation times and reduced hospital length of stay. While pLVAD support did not affect VT recurrence, it was associated with a lower composite end point of 30-day rehospitalization, redo-VT ablation, recurrent implantable cardioverter-defibrillator therapies, and 3-month
Uvelin, Arsen; Pejaković, Jasmina; Mijatović, Vesna
More than 70% of intensive care unit (ICU) patients experience heart rhythm disturbances, and these patients have correspondingly higher mortality rates. Consequently, one of the standards of care in ICUs is continuous electrocardiography monitoring. One of the potentially preventable dysrhythmic events is the occurrence of torsade de pointes ventricular tachycardia in the setting of acquired prolonged QT interval. This type of ventricular tachycardia can be malignant because it often progresses to ventricular fibrillation. Many factors predispose to lengthening of the QT interval, the most important of which are electrolyte abnormalities and the administration of specific medications. In this review, we discuss the pathophysiology of acquired long QT interval, stressing the medication-induced acquired long QT-interval and factors present in ICU patients that promote prolongation of the QT interval. We also propose guidelines to avoid the occurrence of torsade de pointes ventricular tachycardia.
Turagam, Mohit K; Atkins, Donita; Tung, Roderick; Mansour, Moussa; Ruskin, Jeremy; Cheng, Jie; Di Biase, Luigi; Natale, Andrea; Lakkireddy, Dhanunjaya
There are limited studies on the safety and efficacy of remote magnetic navigation (RMN) versus manual navigation (MAN) in ventricular tachycardia (VT) ablation. A comprehensive literature search was performed using the keywords VT ablation, stereotaxis, RMN and MAN in Pubmed, Ebsco, Web of Science, Cochrane, and Google scholar databases. The analysis included seven studies (one randomized, three prospective observational, and three retrospective) including 779 patients [both structural heart disease (SHD) and idiopathic VT] comparing RMN (N = 433) and MAN (N = 339) in VT ablation. The primary end point of long-term VT recurrence was significantly lower with RMN (OR 0.61, 95% CI 0.44-0.85, p = 0.003) compared with MAN. Other end points of acute procedural success (OR 2.13, 95% CI 1.40-3.23, p = 0.0004) was significantly higher with RMN compared with MAN. Fluoroscopy [mean difference -10.42, 95% CI -12.7 to -8.1, p < 0.0001], procedural time [mean difference -9.79, 95% CI -19.27 to -0.3, p = 0.04] and complications (OR 0.35, 95% CI 0.17-0.74, p = 0.0006) were also significantly lower in RMN when compared with MAN. In a subgroup analysis SHD, there was no significant difference in VT recurrence or acute procedural success with RMN vs. MAN. In idiopathic VT, RMN significantly increased acute procedural success with no difference in VT recurrence. The results demonstrate that RMN is safe and effective when compared with MAN in patients with both SHD and idiopathic VT undergoing catheter ablation. Further prospective studies are needed to further verify the safety and efficacy of RMN.
Sapp, John L; Gardner, Martin J; Parkash, Ratika; Basta, Magdy; Warren, James W; Horácek, B Milan
We investigated whether body-surface potential mapping (BSPM) during catheter ablation of scar-related ventricular tachycardia (VT) could assist with the identification of VT exit sites. The study population consisted of 9 patients who underwent catheter ablation for VT, among whom 12 induced VTs with known exit sites were identified by entrainment criteria, pace mapping, or site of successful ablation. Paced activation was initiated at various intracardiac sites (20 +/- 4 sites per patient, a total of 180) documented by nonfluoroscopic electroanatomic mapping. During all episodes of VT and pacing, patients had a 120-lead electrocardiogram recorded, and we analyzed these electrocardiographic data--by means of a similarity coefficient (SC) calculated over 100 milliseconds after the initiation of depolarization--to assess the similarity between the BSPM sequences occurring during VTs and those induced by pacing. Based on 245 observations, the relationship between the SC and the distance of the pacing site from the VT exit site was then obtained for each individual VT by linear regression analysis: the distance D (in millimeters) from the VT exit site was related to SC by the regression equation D = slope (1 - SC2) + intercept. The parameters in this equation varied widely for the 12 VTs, but, in general, the nearer the pacing site was to the exit site, the better the goodness of match. This suggests that, although there is no universally applicable relationship between D and SC, BSPM could provide a useful adjunct to standard pace mapping, although additional processing--namely, an inverse calculation of epicardial potentials/isochrones--may be needed to reliably identify VT exit sites from body-surface electrocardiograms.
Muser, Daniele; Santangeli, Pasquale; Pathak, Rajeev K; Castro, Simon A; Liang, Jackson J; Magnani, Silvia; Hayashi, Tatsuya; Garcia, Fermin C; Hutchinson, Mathew D; Supple, Gregory E; Frankel, David S; Riley, Michael P; Lin, David; Schaller, Robert D; Desjardins, Benoit; Dixit, Sanjay; Callans, David J; Zado, Erica S; Marchlinski, Francis E
Catheter ablation (CA) of ventricular tachycardia (VT) in patients with cardiac sarcoidosis can be challenging because of the complex underlying substrate. We sought to determine the long-term outcome of CA of VT in patients with cardiac sarcoidosis. We enrolled 31 patients (age, 55±10 years) with diagnosis of cardiac sarcoidosis based on Heart Rhythm Society criteria and VT who underwent CA. In 23 (74%) patients, preprocedure cardiac magnetic resonance imaging and positron emission tomographic (PET) evaluation were performed. Preprocedure magnetic resonance imaging was positive for late gadolinium enhancement in 21 of 23 (91%) patients, whereas abnormal 18-fluorodeoxyglucose uptake was found in 15 of 23 (65%) cases. In 14 of 15 patients with positive PET at baseline, PET was repeated after 6.1±3.7-month follow-up. After a median follow-up of 2.5 (range, 0-10.5) years, 1 (3%) patient died and 4 (13%) underwent heart transplant. Overall VT-free survival was 55% at 2-year follow-up. Among the 16 (52%) patients with VT recurrences, CA resulted in a significant reduction of VT burden, with 8 (50%) having only isolated (1-3) VT episodes and only 1 patient with recurrent VT storm. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET at baseline, and lack of PET improvement over follow-up were associated with increased risk of recurrent VT. In patients with cardiac sarcoidosis and VT, CA is effective in achieving long-term freedom from VT or improvement in VT burden in the majority of patients. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET scan at baseline, or lack of improvement at repeat PET over follow-up predict worse arrhythmia-free survival. © 2016 American Heart Association, Inc.
Chan, Yi-Hsin; Wu, Lung-Sheng; Yeh, Yung-Hsin; Wu, Chia-Tung; Wang, Chun-Li; Luqman, Nazar; Chen, Wei-Jan; Hsu, Tzu-Shiu; Kuo, Chi-Tai
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a serious disease with a high mortality but its management is limited. The aim of this study was to investigate specific target sites for therapy in order to find potential management strategies for CPVT. The mutant Ryanodine receptor 2 (RyR2) with reduced stored-overloaded-induced Ca²⁺ release (SOICR) threshold was incorporated into the Luo-Rudy dynamic (LRd) cell model to elucidate the underlying pathologies of CPVT. The simulations reveal that β-adrenergic stimulation increased the Ca²⁺ load in cardiac myocyte, which facilitates spontaneous SR Ca²⁺ leakage, resulting in triggered arrhythmias. Varied blockade (from 0% to 90%) in specific ion channels, including the Na⁺/Ca²⁺ exchanger (I(NaCa)), fast Na⁺ channel (I(Na)), RyR2 receptor (I(rel)), Ca²⁺-ATPase (SERCA) (I(up)) or L-type Ca²⁺channel (I(Ca(L))),was performed to simulate the action of specific drugs on target sites. Blockade of the I(NaCa) (≤ 10% blockade), in contrast to the I(up) (≤ 30% blockade), I(Ca(L)) and I(Na) (≤40% blockade), and followed by I(rel) (≤ 80% blockade), was most effective in suppressing the triggered arrhythmias in CPVT. Specifically, dual blockade of I(Ca(L))/I(up), I(Na)/I(rel) or I(Ca(L))/I(rel) had a synergistic effect in CPVT management. Blockade of I(NaCa) appears to be the most efficacious target for CPVT management. Dual blockade of I(Ca(L))/I(up), I(Na)/I(rel) or I(Ca(L))/I(rel) has a synergistic effect in CPVT treatment.
Tokuda, Michifumi; Kojodjojo, Pipin; Tung, Stanley; Inada, Keiichi; Matsuo, Seiichiro; Yamane, Teiichi; Yoshimura, Michihiro; Tedrow, Usha B; Stevenson, William G
Optimal procedure endpoints of catheter ablation for ventricular tachycardia (VT) are not defined and multiple repeat procedures are sometimes required. However, there are few studies to compare the details of repeat procedures to the initial procedure. The aim of this study is to compare the characteristics of clinical and induced VT throughout multiple procedures and clarify their relations. Of 425 consecutive patients with structural heart disease who underwent catheter VT ablation, second, third and fourth procedures were performed in 101, 23, and 5 patients, respectively. Of 227 VTs that were induced during the second procedure, 68 (30%) VTs had previously been induced at the first procedure. In multivariable analysis, identification of an exit/isthmus site (HR = 0.29, P = 0.047), early termination of VT during radiofrequency application (HR 0.11, P = 0.037) and elimination of target VT at the end of first procedure (HR = 0.43, P = 0.036) were independently associated with noninducibility of the same VT at the second procedure. Over the course of multiple procedures the mean VT cycle length gradually lengthened (381 ± 107, 413 ± 111, 460 ± 124, 507 ± 99 milliseconds in first, second, third, and fourth procedure, respectively, P < 0.001) and more induced VTs became mappable (32%, 40%, 62%, and 70% in first, second, third, and fourth procedure, respectively, P < 0.001). Identification and ablation of VT exit/isthmus, early termination of VT during radiofrequency application and elimination of targeted VT are associated with absence of that VT during a repeat procedure, and recurrences are then mostly due to new VTs or other VTs that were not induced at the first procedure. © 2015 Wiley Periodicals, Inc.
Siontis, Konstantinos C; Kim, Hyungjin Myra; Stevenson, William G; Fujii, Akira; Bella, Paolo Della; Vergara, Pasquale; Shivkumar, Kalyanam; Tung, Roderick; Do, Duc H; Daoud, Emile G; Okabe, Toshimasa; Zeppenfeld, Katja; Riva Silva, Marta de; Hindricks, Gerhard; Arya, Arash; Weber, Alexander; Kuck, Karl-Heinz; Metzner, Andreas; Mathew, Shibu; Riedl, Johannes; Yokokawa, Miki; Jongnarangsin, Krit; Latchamsetty, Rakesh; Morady, Fred; Bogun, Frank M
Recurrence of ventricular tachycardia (VT) after ablation in patients with previous myocardial infarction is associated with adverse prognosis. However, the impact of the timing of VT recurrence on outcomes is unclear. We analyzed data from a multicenter collaborative database of patients who underwent catheter ablation for infarct-related VT. Multivariable Cox regression analyses investigated the effect of the timing of VT recurrence on the composite outcome of death or heart transplantation using VT recurrence as a time-varying covariate. A total of 1412 patients were included (92% men; age: 66.7±10.7 years), and 605 patients (42.8%) had a recurrence after median 116 days (188 [31.1%] within 1 month, 239 [39.5%] between 1 and 12 months, and 178 [29.4%] after 12 months). At median follow-up of 670 days, 375 patients (26.6%) experienced death or heart transplantation. The median time from recurrence to death or heart transplantation was 65 and 198.5 days in patients with recurrence ≤30 days and >30 days post ablation, respectively. The adjusted hazard ratio (95% confidence interval) for the effect of VT recurrence occurring immediately post ablation on death or heart transplantation was 3.45 (2.33-5.11) in reference to no recurrence. However, the magnitude of this effect decreased statistically significantly (P<0.001) as recurrence occurred later in the follow-up period. The respective risk estimates for VT recurrence at 30 days, 6 months, 1 year, and 2 years were 3.36 (2.29-4.93), 2.94 (2.09-4.14), 2.50 (1.85-3.37), and 1.81 (1.37-2.40). VT recurrence post ablation is associated with a mortality risk that is highest soon after the ablation and decreases gradually thereafter. © 2016 American Heart Association, Inc.
Reithmann, Christopher; Herkommer, Bernhard; Fiek, Michael
Sustained ventricular tachycardia (VT) in patients with nonischemic cardiomyopathy (NICM) often involves midmyocardial and epicardial structures. Delayed-enhancement magnetic resonance imaging (DE-MRI) of scar and fibrosis is the method of choice to define the substrate of monomorphic VT. The aim of the study was to compare the outcome of endocardial vs. epicardial VT ablation in patients with epicardial DE-MRI substrates in NICM. Among 44 patients with NICM referred for VT ablation who underwent DE-MRI, 12 patients had an epicardial-only (n = 4) or predominantly epicardial DE-MRI substrate (n = 8). 9 of the 12 patients had a prior myocarditis. Endocardial-only VT ablation was successful in two patients with epicardial DE-MRI substrate. A pericardial access for epicardial mapping and ablation was attempted in 8 patients and could be accomplished in seven. Epicardial low voltage (<1.5 mV) and very low voltage (<0.5 mV) areas were in good qualitative correlation to the epicardial DE-MRI substrates. Epicardial abnormal electrograms in combination with a good pace map QRS match were found in epicardial very low voltage areas in five patients and in low voltage areas in two patients. 2 patients with endocardial-only ablation, five patients with endo-epicardial ablation and two patients with primary epicardial ablation had a favorable post-ablation outcome (follow-up 32 ± 26 months) but one patient had to undergo heart transplantation for heart failure deterioration. Endo-epicardial ablation or primary epicardial ablation should early be considered in patients after myocarditis or with other forms of nonischemic cardiomyopathy with epicardial DE-MRI substrates.
Njeim, Mario; Yokokawa, Miki; Frank, Luba; Crawford, Thomas; Good, Eric; Morady, Fred; Bogun, Frank
Ventricular tachycardia (VT) in patients with cardiomyopathy originates in scar tissue. Intramural or epicardial scar may result in ineffective ablation if mapping and ablation are limited to the endocardium. The purpose of this study was to investigate whether preprocedural magnetic resonance imaging (MRI) is beneficial in patients with failed endocardial VT ablations in determining an appropriate ablation strategy. A cardiac MRI was performed in 20 patients with a failed ablation procedure and cardiomyopathy (nonischemic n = 12, ischemic n = 8). A subsequent ablation strategy was determined by a delayed enhanced MRI (DE-MRI) and an epicardial subxyphoid access was planned only in patients with epicardial or intramural free-wall scar. MRIs were performed in all patients with or without an implanted cardioverter defibrillator (ICD). The location of scar tissue in the MRI predicted the origin of VT in all patients. In 9/20 patients an epicardial procedure was performed based on the result of the MRI. An endocardial procedure was performed in the remaining 11 patients who had either endocardial or septal scarring and one patient in whom the MRI only showed artifact. Five patients remained inducible postablation and four patients had VT recurrence within a follow-up period of 17 ± 22 months. All of the latter patients had an intramural scar pattern. Imaging with DE-MRI prior to VT ablation in patients with previously failed endocardial ablation procedures is beneficial in identifying an ablation strategy, helps to focus on an area of interest intraprocedurally, and provides valuable outcomes information. © 2015 Wiley Periodicals, Inc.
Nazer, Babak; Woods, Christopher; Dewland, Thomas; Moyers, Brian; Badhwar, Nitish; Gerstenfeld, Edward P
Many nonischemic cardiomyopathy (NICMP) patients referred for catheter ablation of ventricular tachycardia (VT) undergo an initial epicardial approach under general anesthesia (GA). However, GA may suppress inducibility and decrease tolerance of induced VT, leaving substrate modification as the sole ablation method. Determine the utility of a strategy of initial programmed electrical stimulation (PES) under light sedation in patients referred for epicardial ablation of VT. Of 68 NICMP patients referred for VT ablation, 25 were referred specifically for epicardial ablation. All patients underwent PES under conscious sedation, with conversion to GA and epicardial access only if VT morphology and/or endocardial mapping suggested an epicardial substrate. VT was induced with PES in 24 of 25 patients (mean age 52 years; 76% male; ejection fraction 38 ± 18%). VT was hemodynamically tolerated in 63% and unstable in 38% of patients. The noninducible/unstable VT patients underwent substrate modification based on voltage and pace mapping. Of the patients with stable VT, 73% were mapped and ablated endocardially (six right ventricle, three left ventricle, one left coronary cusp, one middle cardiac vein), and 33% were successfully ablated in areas of normal endocardial voltage. After ablation, the clinical VT was noninducible in all patients. After mean follow-up of 10 months, 80% were free of implantable cardioverter defibrillator shocks or sustained VT. An initial approach of PES and entrainment mapping under conscious sedation is critically important for patients with NICMP referred for epicardial ablation. Empiric ablation of endocardial/epicardial scar would have missed the clinical VT in 20% of patients. © 2015 Wiley Periodicals, Inc.
Fukuzawa, Koji; Yoshida, Akihiro; Kubo, Shinya; Takano, Takatsugu; Kiuchi, Kunihiko; Kanda, Gaku; Takami, Kaoru; Kumagai, Hiroyuki; Torii, Satoko; Takami, Mitsuru; Yokoyama, Mitsuhiro; Hirata, Ken-ichi
We investigated the differences in the endocardial substrates between ischemic cardiomyopathy (ICM) and non-ICM (NICM) by using electro-anatomical mapping and pace-mapping. We studied 18 patients (ICM and NICM, 9 each) with monomorphic ventricular tachycardia (VT) documented by 12-leads ECG. Low voltage area was defined by signal amplitude <1.5 mV. A pace-map QRS morphology that matched VT in >10 of the 12-leads ECG was regarded as a pace-map match. And conduction delay during pace-mapping was defined as the stimulus to QRS interval >or=40 ms. Low voltage area was 53.8 +/- 21.5 and 20.8 +/- 16.7 cm2 in ICM and NICM patients, respectively (P = 0.002). Pace-mapping was assessed in 6 ICM and 9 NICM. Pace-map match with conduction delay were obtained in all the 6 ICM patients. But in NICM patients, pace-map match with conduction delay was obtained in 3 patients. Pace-map match sites where conduction delay was not observed were obtained in 5 patients. Pace-map match could not be obtained in 1 patient. We attempted ablation in 6 ICM and 7 NICM patients. Subsequently, VT recurrence was not observed in ICM but it was observed in 6 of 7 NICM patients (log-rank P = 0.0016). In NICM patients, the arrhythmogenic substrate that represented the abnormal electrogram and conduction delay was observed less within the endocardial surface when compared with that observed in ICM. VT recurrence rate subsequent to endocardial ablation was higher in NICM than in ICM patients.
Schurmann, Paul; Ibarra-Cortez, Sergio Hugo; Dave, Amish S.; Valderrábano, Miguel
Background Radiofrequency ablation (RFA) of ventricular tachycardia (VT) can fail due to inaccessibility to the VT substrate. Trans-arterial coronary ethanol ablation (TCEA) can be effective, but entails arterial instrumentation risk. We hypothesized that retrograde coronary venous ethanol ablation (RCVEA) can be an alternative bail-out approach to failed VT RFA. Methods and Results Out of 334 consecutive patients undergoing VT/PVC ablation, seven patients underwent RCVEA. Six of seven patients had failed RFA attempts (including epicardial in 3). Coronary venogram-guided venous mapping was performed using a 4F quadripolar catheter or an alligator-clip-connected angioplasty wire. Targeted veins included those with early pre-systolic potentials and pace-maps matching VT/PVC. An angioplasty balloon (1.5-2 × 6 mm) was used to deliver 1-4 cc of 98% ethanol into a septal branch of the anterior interventricular vein (AIV) in 5 patients with LV summit VT, a septal branch of the middle cardiac vein, and a postero-lateral coronary vein (n=1 each). The clinical VT was successfully ablated acutely in all patients. There were no complications of RCVEA, but one patient developed pericardial and pleural effusion attributed to pericardial instrumentation. On follow-up of 590 ±722 days, VT recurred in 4/7 patients, three of whom were successfully re-ablated with RFA. Conclusions RCVEA is safe and feasible as a bail-out approach to failed VT RFA, particularly those originating from the LV summit. PMID:27406606
Relan, Jatin; Chinchapatnam, Phani; Sermesant, Maxime; Rhode, Kawal; Ginks, Matt; Delingette, Hervé; Rinaldi, C. Aldo; Razavi, Reza; Ayache, Nicholas
In order to translate the important progress in cardiac electrophysiology modelling of the last decades into clinical applications, there is a requirement to make macroscopic models that can be used for the planning and performance of the clinical procedures. This requires model personalization, i.e. estimation of patient-specific model parameters and computations compatible with clinical constraints. Simplified macroscopic models can allow a rapid estimation of the tissue conductivity, but are often unreliable to predict arrhythmias. Conversely, complex biophysical models are more complete and have mechanisms of arrhythmogenesis and arrhythmia sustainibility, but are computationally expensive and their predictions at the organ scale still have to be validated. We present a coupled personalization framework that combines the power of the two kinds of models while keeping the computational complexity tractable. A simple eikonal model is used to estimate the conductivity parameters, which are then used to set the parameters of a biophysical model, the Mitchell–Schaeffer (MS) model. Additional parameters related to action potential duration restitution curves for the tissue are further estimated for the MS model. This framework is applied to a clinical dataset derived from a hybrid X-ray/magnetic resonance imaging and non-contact mapping procedure on a patient with heart failure. This personalized MS model is then used to perform an in silico simulation of a ventricular tachycardia (VT) stimulation protocol to predict the induction of VT. This proof of concept opens up possibilities of using VT induction modelling in order to both assess the risk of VT for a given patient and also to plan a potential subsequent radio-frequency ablation strategy to treat VT. PMID:22670209
Relan, Jatin; Chinchapatnam, Phani; Sermesant, Maxime; Rhode, Kawal; Ginks, Matt; Delingette, Hervé; Rinaldi, C Aldo; Razavi, Reza; Ayache, Nicholas
In order to translate the important progress in cardiac electrophysiology modelling of the last decades into clinical applications, there is a requirement to make macroscopic models that can be used for the planning and performance of the clinical procedures. This requires model personalization, i.e. estimation of patient-specific model parameters and computations compatible with clinical constraints. Simplified macroscopic models can allow a rapid estimation of the tissue conductivity, but are often unreliable to predict arrhythmias. Conversely, complex biophysical models are more complete and have mechanisms of arrhythmogenesis and arrhythmia sustainibility, but are computationally expensive and their predictions at the organ scale still have to be validated. We present a coupled personalization framework that combines the power of the two kinds of models while keeping the computational complexity tractable. A simple eikonal model is used to estimate the conductivity parameters, which are then used to set the parameters of a biophysical model, the Mitchell-Schaeffer (MS) model. Additional parameters related to action potential duration restitution curves for the tissue are further estimated for the MS model. This framework is applied to a clinical dataset derived from a hybrid X-ray/magnetic resonance imaging and non-contact mapping procedure on a patient with heart failure. This personalized MS model is then used to perform an in silico simulation of a ventricular tachycardia (VT) stimulation protocol to predict the induction of VT. This proof of concept opens up possibilities of using VT induction modelling in order to both assess the risk of VT for a given patient and also to plan a potential subsequent radio-frequency ablation strategy to treat VT.
Tan, Zhen; Xiao, Zhichao; Wei, Jinhong; Zhang, Jingqun; Zhou, Qiang; Smith, Chris D; Nani, Alma; Wu, Guogen; Song, Long-Sheng; Back, Thomas G; Fill, Michael; Chen, S R Wayne
β-Blockers are a standard treatment for heart failure and cardiac arrhythmias. There are ∼30 commonly used β-blockers, representing a diverse class of drugs with different receptor affinities and pleiotropic properties. We reported that among 14 β-blockers tested previously, only carvedilol effectively suppressed cardiac ryanodine receptor (RyR2)-mediated spontaneous Ca(2+) waves during store Ca(2+) overload, also known as store overload-induced Ca(2+) release (SOICR). Given the critical role of SOICR in arrhythmogenesis, it is of importance to determine whether there are other β-blockers that suppress SOICR. Here, we assessed the effect of other commonly used β-blockers on RyR2-mediated SOICR in HEK293 cells, using single-cell Ca(2+) imaging. Of the 13 β-blockers tested, only nebivolol, a β-1-selective β-blocker with nitric oxide synthase (NOS)-stimulating action, effectively suppressed SOICR. The NOS inhibitor (N-nitro-l-arginine methyl ester) had no effect on nebivolol's SOICR inhibition, and the NOS activator (histamine or prostaglandin E2) alone did not inhibit SOICR. Hence, nebivolol's SOICR inhibition was independent of NOS stimulation. Like carvedilol, nebivolol reduced the opening of single RyR2 channels and suppressed spontaneous Ca(2+) waves in intact hearts and catecholaminergic polymorphic ventricular tachycardia (CPVT) in the mice harboring a RyR2 mutation (R4496C). Interestingly, a non-β-blocking nebivolol enantiomer, (l)-nebivolol, also suppressed SOICR and CPVT without lowering heart rate. These data indicate that nebivolol, like carvedilol, possesses a RyR2-targeted action that suppresses SOICR and SOICR-evoked VTs. Thus, nebivolol represents a promising agent for Ca(2+)-triggered arrhythmias. © 2016 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.
Servatius, Helge; Höfeler, Thormen; Hoffmann, Boris A; Sultan, Arian; Lüker, Jakob; Schäffer, Benjamin; Willems, Stephan; Steven, Daniel
Propofol sedation has been shown to be safe for atrial fibrillation ablation and internal cardioverter-defibrillator implantation but its use for catheter ablation (CA) of ventricular tachycardia (VT) has yet to be evaluated. Here, we tested the hypothesis that VT ablation can be performed using propofol sedation administered by trained nurses under a cardiologist's supervision. Data of 205 procedures (157 patients, 1.3 procedures/patient) undergoing CA for sustained VT under propofol sedation were analysed. The primary endpoint was change of sedation and/or discontinuation of propofol sedation due to side effects and/or haemodynamic instability. Propofol cessation was necessary in 24 of 205 procedures. These procedures (Group A; n = 24, 11.7%) were compared with those with continued propofol sedation (Group B; n = 181, 88.3%). Propofol sedation was discontinued due to hypotension (n = 22; 10.7%), insufficient oxygenation (n = 1, 0.5%), or hypersalivation (n = 1, 0.5%). Procedures in Group A were significantly longer (210 [180-260] vs. 180 [125-220] min, P = 0.005), had a lower per hour propofol rate (3.0 ± 1.2 vs. 3.8 ± 1.2 mg/kg of body weight/h, P = 0.004), and higher cumulative dose of fentanyl administered (0.15 [0.13-0.25] vs. 0.1 [0.05-0.13] mg, P < 0.001), compared with patients in Group B. Five (2.4%) adverse events occurred. Sedation using propofol can be safely performed for VT ablation under the supervision of cardiologists. Close haemodynamic monitoring is required, especially in elderly patients and during lengthy procedures, which carrying a higher risk for systolic blood pressure decline. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: firstname.lastname@example.org.
Richardson, Ebony; Spinks, Catherine; Davis, Andrew; Turner, Christian; Atherton, John; McGaughran, Julie; Semsarian, Christopher; Ingles, Jodie
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited arrhythmogenic disease with a high risk of sudden cardiac death. The impact on health-related quality of life (HR-QoL) and psychosocial outcomes is not known. We sought to provide the first description of HR-QoL and psychosocial wellbeing of adults with CPVT, parents of affected children and at-risk relatives. Participants were recruited through the Australian Genetic Heart Disease Registry and invited to complete a cross-sectional survey comprising a number of validated scales and open-ended questions. Thirty-five participants completed surveys (response rate 65%), including 19 with CPVT, 10 unaffected parents of a child with CPVT, and 7 at-risk relatives (one participant considered patient and parent). Young patients <40 years were significantly more likely to report anxiety (p = 0.04), depression (p = 0.03) and posttraumatic stress symptoms (p = 0.02) compared to older CPVT patients. Further, young patients with an implantable cardioverter defibrillator (ICD) reported significantly worse device-related distress (p = 0.04) and shock anxiety (p = 0.003). Patients with a genetic diagnosis had worse psychological adaptation than those patients without a gene result. Parents perceived their affected children to have poor quality of life across all subdomains compared to healthy age-matched children, however quality of life of parents and at-risk relatives was comparable to population norms. Ongoing psychosocial care is required for young people with CPVT. Those with an ICD and/or undergoing genetic testing may require additional support. The challenges of CPVT management should extend beyond the clinical and genetic aspects of care to incorporate greater psychosocial support, and further reinforces the need for a multidisciplinary approach to care.
Bogossian, Harilaos; Stempfl, Johanna; Seeger, Werner; Hecker, Matthias; Ghofrani, Ardeschir; Hoeltgen, Reinhard; Gall, Henning
Background. Increased pulmonary vascular resistance in patients with pulmonary hypertension (PH) leads to an increased afterload of right heart and cardiac remodeling which could provide the substrate or trigger for arrhythmias. Supraventricular arrhythmias were associated with clinical deterioration but were not associated with sudden cardiac death (SCD). SCD has been reported to account for approximately 30% of deaths in patients with pulmonary arterial hypertension (PAH). Objective. The role of nonsustained ventricular tachycardia (nsVT) and its prognostic relevance in patients with PH remains unclear. This study evaluated the prognostic relevance of nsVT in patients with PAH and chronic thromboembolic pulmonary hypertension (CTEPH). Methods. Retrospectively, patients with PAH and CTEPH who underwent Holter ECG monitoring and available data of survival were investigated. Results. Seventy-eight (PAH: 55, CTEPH: 23) patients were evaluated. Holter ECG revealed nsVT in 12 patients. Twenty-one patients died during follow-up. In patients with nsVT, tricuspid annular plane systolic excursion was lower (p = 0.001), and systolic pulmonary arterial pressure was higher (p = 0.163). Mean survival of patients without/with nsVT was 155.2 ± 8.5/146.4 ± 21.4 months (p = 0.690). The association between arrhythmias and survival was not confounded by age (p = 0.681), gender (p = 0.752), 6-MW distance (p = 0.196), or arterial hypertension (p = 0.238). Conclusions. In patients with PH, nsVT occurs more often than previously reported, and patients with PH group 1 seem to be more at risk. PMID:28090536
Itzhaki, Ilanit; Maizels, Leonid; Huber, Irit; Gepstein, Amira; Arbel, Gil; Caspi, Oren; Miller, Liron; Belhassen, Bernard; Nof, Eyal; Glikson, Michael; Gepstein, Lior
The goal of this study was to establish a patient-specific human-induced pluripotent stem cells (hiPSCs) model of catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT is a familial arrhythmogenic syndrome characterized by abnormal calcium (Ca(2+)) handling, ventricular arrhythmias, and sudden cardiac death. Dermal fibroblasts were obtained from a CPVT patient due to the M4109R heterozygous point RYR2 mutation and reprogrammed to generate the CPVT-hiPSCs. The patient-specific hiPSCs were coaxed to differentiate into the cardiac lineage and compared with healthy control hiPSCs-derived cardiomyocytes (hiPSCs-CMs). Intracellular electrophysiological recordings demonstrated the development of delayed afterdepolarizations in 69% of the CPVT-hiPSCs-CMs compared with 11% in healthy control cardiomyocytes. Adrenergic stimulation by isoproterenol (1 μM) or forskolin (5 μM) increased the frequency and magnitude of afterdepolarizations and also led to development of triggered activity in the CPVT-hiPSCs-CMs. In contrast, flecainide (10 μM) and thapsigargin (10 μM) eliminated all afterdepolarizations in these cells. The latter finding suggests an important role for internal Ca(2+) stores in the pathogenesis of delayed afterdepolarizations. Laser-confocal Ca(2+) imaging revealed significant whole-cell [Ca(2+)] transient irregularities (frequent local and large-storage Ca(2+)-release events, broad and double-humped transients, and triggered activity) in the CPVT cardiomyocytes that worsened with adrenergic stimulation and Ca(2+) overload and improved with beta-blockers. Store-overload-induced Ca(2+) release was also identified in the hiPSCs-CMs and the threshold for such events was significantly reduced in the CPVT cells. This study highlights the potential of hiPSCs for studying inherited arrhythmogenic syndromes, in general, and CPVT specifically. As such, it represents a promising paradigm to study disease mechanisms, optimize patient care, and aid in the
Electrocardiogram features of premature ventricular contractions/ventricular tachycardia originating from the left ventricular outflow tract and the treatment outcome of radiofrequency catheter ablation
Background Radiofrequency catheter ablation (RFCA) has been used for the ablation of premature ventricular contractions (PVCs) or ventricular tachycardia (VT). To date, the mapping and catheter ablation of the arrhythmias originating from the left ventricular outflow tract (LVOT) has not been specified. This study investigates the electrocardiogram (ECG) feature of PVCs or VT originating from the LVOT. Moreover, the treatment outcome of RFCA is analyzed. Methods Mapping and ablation were performed on the supravalvular or subvalvular aorta in 52 cases with PVCs/VT originating from the LVOT. The data were compared with those from 104 patients with PVCs/VT originating from the right ventricular outflow tract (RVOT). A differential procedure was prepared based on the comparison of the ECG features of PVCs/VT originating from the RVOT, LVOT, and their different parts. Results Among 52 cases with PVCs originating from the LVOT, 47 were successfully treated by RFCA, with a success rate of 90.38%. Several differences among the 12-lead ECG features were observed from the RVOT and LVOT in the left and right coronary sinus groups, as well as under the left coronary sinus group (left fibrous trigone): (1) If the precordial leads transition
Jomaa, W; Selmi, W; Hamdi, S; Azaiez, M A; El Hraiech, A; Ben Hamda, K; Maatouk, F
We report the case of a 2-month old infant who experienced recurrent sustained ventricular tachycardia (VT) in a structurally normal heart. Resting electrocardiogram (ECG) showed wide QRS with a complete right bundle branch bloc (RBBB) morphology. There was no family history of syncope or sudden death, but the ECGs of the father and the brother showed incomplete RBBB with negative T waves on V1 lead. This case seems to fit well with the newly defined entity of Brugada-like syndrome with a highly suspected genetic underlying disposition.
Sakamoto, Kazuo; Nozoe, Masatsugu; Tsutsui, Yoshitomo; Suematsu, Nobuhiro; Kubota, Toru; Okabe, Masanori; Yamamoto, Yusuke
Cardiac magnetic resonance imaging (MRI) is a useful tool for detecting the arrhythmogenic substrate in cardiac sarcoidosis. We herein present a case of bipolar radiofrequency catheter ablation for ventricular tachycardia (VT) complicated with cardiac sarcoidosis, guided by pre-procedural cardiac MRI. Neither echocardiography nor endocardial voltage mapping suggested a septal VT substrate. However, MRI alone detected intramural lesions in the septum. Although application of endocardial energy failed to treat the VT, bipolar ablation targeting the potential substrate identified by MRI successfully eliminated the VT. Even when no abnormalities are depicted on echocardiography and endocardial voltage mapping, intramural scar tissue identified by cardiac MRI could be critical for VT. PMID:28546773
Dasatinib and Prednisolone Induction Therapy for a Case of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia with Dilated Cardiomyopathy Accompanied by Life-Threatening Ventricular Tachycardia
Nakamae, Hirohisa; Matsumoto, Kana; Morita, Kunihiko; Koga, Yuki; Momose, Dai; Hino, Masayuki
A 56-year-old man being treated for dilated cardiomyopathy presented with epigastralgia. He was diagnosed with ventricular tachycardia and Philadelphia chromosome-positive acute lymphoblastic leukemia. After treating incessant ventricular tachycardia, we commenced induction therapy for leukemia with dasatinib and prednisolone to minimize toxicity towards cardiomyocytes and the cardiac conduction system. Although dasatinib was temporarily withheld because of a recurrence of ventricular tachycardia, we rechallenged dasatinib while using bisoprolol and amiodarone and achieved a complete hematological response three weeks later. Although drug interactions between dasatinib and amiodarone were of concern, the blood concentration of each drug remained within the safe range after concomitant use, and there were no adverse cardiac effects such as QT prolongation after rechallenging dasatinib. Induction therapy with dasatinib and prednisolone may be an acceptable therapeutic option for Philadelphia chromosome-positive acute lymphoblastic leukemia with severe cardiac complications. PMID:28326207
Brembilla-Perrot, B; Terrier de la Chaise, A; Briançon, S; Takoordial, M; Suty-Selton, C; Thiel, B; Brua, J L
Rapid uniform ventricular tachycardia (VT) (> 270 beats/min) or ventricular flutter induced during electrophysiological studies is thought not to be clinically significant in patients without cardiac arrest or documented rapid VT. The purpose of the study was to follow up 73 patients with inducible ventricular flutter but without confirmed rapid spontaneous VT. A long follow up (mean 3.5 years) identified two groups of patients. The first group had an excellent outcome and was characterised by a normal 24 hour Holter monitoring. In the second group, however, the risk of cardiac mortality was high (35%) and spontaneous VT was < 270 beats/min (26%) and was characterised by couplets or salvos of extrasystoles on Holter monitoring. In this group the history of syncope and decreased left ejection fraction increased the risk of mortality and VT. The presence of late potentials increased the risk of spontaneous VT. Electrophysiologically guided antiarrhythmic therapy reduced the risk of VT. Ventricular flutter was a non-specific finding in patients with normal Holter monitoring. In contrast, in patients with salvos of extrasystoles, ventricular flutter was associated with a high risk of cardiac mortality and VT. PMID:8457388
Song, Mi Kyoung; Bae, Eun Jung; Baek, Jae Suk; Kwon, Bo Sang; Kim, Gi Beom; Noh, Chung Il; Choi, Jung Yun; Park, Sung Sup
QT prolongation is a serious adverse drug effect, which is associated with an increased risk of Torsade de pointes and sudden death. Many drugs, including both cardiac and non-cardiac drugs, have been reported to cause prolongation of QT interval. Although meperidine has not been considered proarrhythmic, we present a unique case of a 16-year-old boy without an underlying cardiac disease, who developed polymorphic ventricular tachycardia, ventricular fibrillation and QT prolongation after an intravenous meperidine injection. He had no mutation in long QT syndrome genes (KCNQ1, KCNH2, and SCN5A), but single nucleotide polymorphisms were reported, including H558R in SCNA5A and K897T in KCNH2.
Aldhoon, Bashar; Wichterle, Dan; Peichl, Petr; Čihák, Robert; Kautzner, Josef
Aims To investigate predictors of long-term outcomes after catheter ablation (CA) for ventricular tachycardia (VT) and the impact of electrical storm (ES) prior to index ablation procedures. Methods We studied consecutive patients with structural heart disease and VT (n = 328; age: 63±12 years; 88% males; 72% ischaemic cardiomyopathy; LVEF: 32±12%) who had undergone CA. According to presenting arrhythmia at baseline, they were divided into ES (n = 93, 28%) and non-ES groups. Clinical predictors of all-cause mortality were investigated and a clinically useful risk score (SCORE) was constructed. Results During a median follow-up of 927 days (IQR: 564–1626), 67% vs. 60% of patients (p = 0.05) experienced VT recurrence in the ES vs. the non-ES group, respectively; and 41% vs. 32% patients died (p = 0.02), respectively. Five factors were independently associated with mortality: age >70 years (hazard ratio (HR): 1.6, 95% confidence interval (CI): 1.1–2.4, p = 0.01), NYHA class ≥3 (HR: 1.9, 95% CI: 1.2–2.9, p = 0.005), a serum creatinine level >1.3 mg/dL (HR: 1.6, 95% CI: 1.1–2.3, p = 0.02), LVEF ≤25% (HR: 2.4, 95% CI: 1.6–3.5, p = 0.00004), and amiodarone therapy (HR: 1.5, 95% CI: 1.0–2.2, p = 0.03). A risk SCORE ranging from 0–4 (1 point for either high-risk age, NYHA, creatinine, or LVEF) correlated with mortality. ES during index ablation independently predicted mortality only in patients with a SCORE ≤1. Conclusions Advanced LV dysfunction, older age, higher NYHA class, renal dysfunction, and amiodarone therapy, but not ES, were predictors of poor outcomes after CA for VT in the total population. However, ES did predict mortality in a low-risk sub-group of patients. PMID:28187168
Katz, David F; Turakhia, Mintu P; Sauer, William H; Tzou, Wendy S; Heath, Russell R; Zipse, Matthew M; Aleong, Ryan G; Varosy, Paul D; Kao, David P
Outcomes of ventricular tachycardia (VT) ablation have been described in clinical trials and single-center studies. We assessed the safety of VT ablation in clinical practice. Using administrative hospitalization data between 1994 and 2011, we identified hospitalizations with primary diagnosis of VT (International Classification of Diseases-9 Clinical Modification code: 427.1) and cardiac ablation (International Classification of Diseases-9 Clinical Modification code: 37.34). We quantified in-hospital adverse events (AEs), including death, stroke, intracerebral hemorrhage, pericardial complications, hematoma or hemorrhage, blood transfusion, or cardiogenic shock. Secondary outcomes included major AEs (stroke, tamponade, or death) and death. Multivariable mixed effects models identified patient and hospital characteristics associated with AEs. Of 9699 hospitalizations with VT ablations (age, 56.5 ± 17.6; 60.1% men), AEs were reported in 825 (8.5%), major AEs in 295 (3.0%), and death in 110 (1.1%). Heart failure had the strongest association with death (odds ratio, 5.52; 95% confidence interval, 2.97-10.3) and major AE (odds ratio, 2.99; 95% confidence interval, 2.15-4.16). Anemia (odds ratio, 4.84; 95% confidence interval, 3.79-6.19) and unscheduled admission (odds ratio, 1.64; 95% confidence interval, 1.37-1.97) were associated with AEs. During the study period, incidence of AEs increased from 9.2% to 12.8% as did the burden of AE risk factors (0.034 patient/y; P < 0.001). Hospital volume > 25 cases/y was associated with fewer AEs compared with lower volume centers (6.4% versus 8.8%; P = 0.008). VT ablation-associated AE rates in clinical practice are similar to those reported in the literature. Over time rates have increased as have the number of AE risk factors per patient. Ablations done electively and at hospitals with higher procedural volume are associated with lower incidence of AEs. © 2015 American Heart Association, Inc.
Parks, C.; Manohar, M.; Lundeen, G.
To examine the effects of tachycardia on coronary circulation, transmural distribution of myocardial blood flow (MBF, 15-micron diameter radionuclide-labeled microspheres) was studied in six healthy adult ponies at rest (heart rate . 60 +/- 7 beats . min-1), during ventricular pacing at 150 and 200 beats . min-1, as well as with ventricular pacing at 250 beats . min-1 before and during maximal coronary vasodilatation (iv adenosine infusion; 4 mumole . kg-1 . min-1). Mean aortic pressure and cardiac output were unchanged from control values with ventricular pacing. Whereas ventricular pacing at 150 and 200 beats . min-1 resulted in a progressive uniform increase in transmural MBF and well-maintained endo:epi perfusion ratio, pacing at 250 beats . min-1 did not result in a further increase in MBF compared to pacing at 200 beats . min-1 and the left ventricular (LV) subendocardial:subepicardial (endo:epi) perfusion ratio was significantly less than 1.00 (0.87 +/- 0.05). Blood flow to the LV papillary muscles and subendocardium was significantly less than that recorded at 200 beats . min-1. The LV endo:epi perfusion ratio with ventricular pacing at 250 beats . min-1 during adenosine infusion resulted in a decrease in mean aortic pressure (63% of control value) and a marked further reduction in blood flow to the LV papillary muscles as well as the LV subendocardium, while MBF increased dramatically in the LV subepicardium compared to values observed during ventricular pacing at 250 beats . min-1 alone. These data demonstrate that coronary vasomotion functions to maintain LV subendocardial blood flow in the pony myocardium at a heart rate of 200 beats . min-1, while at 250 beats . min-1 exhaustion of coronary vasodilator reserve in the deeper layers limits further increase in MBF.
Roy Chowdhury, Shubhajit
The paper presents a field-programmable gate array (FPGA)-based fast processing system with 12-channel high-resolution (24 bits) front-end for ECG signal processing. The implemented high-resolution data conversion makes the system suitable for recording of late potentials of the QRS complex in patients prone to sustained ventricular tachycardia. The system accepts ECG signals through 12 channels and then filtered to minimize baseline wander and power-line interference. The filter outputs are connected to 12 delta-sigma ADCs. The whole ADCs work synchronously at 8 kHz sampling frequency, and their output data are transferred to an FPGA that computes online on the digitized sample values in real time and ascertains whether the patient under study suffers from ventricular tachycardia or not. In order to ascertain the QRS complex accurately in the noisy ECG signal, fuzzy entropy of the sample values has been computed and provided as an input to inverse multiquadratic radial basis function neural network. Using the standard CSE ECG database, the algorithm performed highly effectively. The performance of the algorithm in respect of QRS detection with sensitivity of 99.83 % and accuracy of 99.7 % is achieved when tested using single-channel ECG with entropy criteria. The performance of the QRS detection system has been compared and found to be better than most of the QRS detection systems available in the literature. Using the system, 200 patients have been diagnosed with an accuracy of 99 %.
Jan, Matevž; Žižek, David; Rupar, Katja; Mazić, Uroš; Kuhelj, Dimitrij; Lakič, Nikola; Geršak, Borut
Electrophysiology study (EPS) and catheter ablation (CA) in children and adolescents carries a potentially harmful effect of radiation exposure when performed with the use of fluoroscopy. Our aim was to evaluate the feasibility, safety and effectiveness of fluoroless EPS and CA of various supra-ventricular tachycardias (SVTs) with the use of the 3D mapping system and intracardiac echocardiography (ICE). Forty-three consecutive children and adolescents (age 13 ± 3 years) underwent fluoroless EPS and CA for various supra-ventricular tachycardias. A three-dimensional (3D) mapping system NavX™ was used for guidance of diagnostic and ablation catheters in the heart. ICE was used as a fundamental imaging tool for transseptal punctures. Acute procedural success rate was 100 %. There were no procedure related complications and short-term follow up (10 ± 3 months) revealed 93 % arrhythmia free survival rate. Fluoroless CA of various SVTs in the paediatric population is feasible, safe and can be performed successfully with 3D mapping system and ICE.
Nof, Eyal; Belhassen, Bernard; Arad, Michael; Bhuiyan, Zahurul A; Antzelevitch, Charles; Rosso, Raphael; Fogelman, Rami; Luria, David; El-Ani, Dalia; Mannens, Marcel M A M; Viskin, Sami; Eldar, Michael; Wilde, Arthur A M; Glikson, Michael
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease for which electrophysiological studies (EPS) have shown to be of limited value. This study presents a CPVT family in which marked postpacing repolarization abnormalities during EPS were the only consistent phenotypic manifestation of ryanodine receptor (RyR2) mutation carriers. The study was prompted by the observation of transient marked QT prolongation preceding initiation of ventricular fibrillation during atrial fibrillation in a boy with a family history of sudden cardiac death (SCD). Family members underwent exercise and pharmacologic electrocardiographic testing with epinephrine, adenosine, and flecainide. Noninvasive clinical test results were normal in 10 patients evaluated, except for both epinephrine- and exercise-induced ventricular arrhythmias in 1. EPS included bursts of ventricular pacing and programmed ventricular extrastimulation reproducing short-long sequences. Genetic screening involved direct sequencing of genes involved in long QT syndrome as well as RyR2. Six patients demonstrated a marked increase in QT interval only in the first beat after cessation of ventricular pacing and/or extrastimulation. All 6 patients were found to have a heterozygous missense mutation (M4109R) in RyR2. Two of them, presenting with aborted SCD, also had a second missense mutation (I406T- RyR2). Four family members without RyR2 mutations did not display prominent postpacing QT changes. M4109R- RyR2 is associated with a high incidence of SCD. The contribution of I406T to the clinical phenotype is unclear. In contrast to exercise testing, marked postpacing repolarization changes in a single beat accurately predicted carriers of M4109R- RyR2 in this family. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Mjahad, A; Rosado-Muñoz, A; Bataller-Mompeán, M; Francés-Víllora, J V; Guerrero-Martínez, J F
To safely select the proper therapy for Ventricullar Fibrillation (VF) is essential to distinct it correctly from Ventricular Tachycardia (VT) and other rhythms. Provided that the required therapy would not be the same, an erroneous detection might lead to serious injuries to the patient or even cause Ventricular Fibrillation (VF). The main novelty of this paper is the use of time-frequency (t-f) representation images as the direct input to the classifier. We hypothesize that this method allow to improve classification results as it allows to eliminate the typical feature selection and extraction stage, and its corresponding loss of information. The standard AHA and MIT-BIH databases were used for evaluation and comparison with other authors. Previous to t-f Pseudo Wigner-Ville (PWV) calculation, only a basic preprocessing for denoising and signal alignment is necessary. In order to check the validity of the method independently of the classifier, four different classifiers are used: Logistic Regression with L2 Regularization (L2 RLR), Adaptive Neural Network Classifier (ANNC), Support Vector Machine (SSVM), and Bagging classifier (BAGG). The main classification results for VF detection (including flutter episodes) are 95.56% sensitivity and 98.8% specificity, 88.80% sensitivity and 99.5% specificity for ventricular tachycardia (VT), 98.98% sensitivity and 97.7% specificity for normal sinus, and 96.87% sensitivity and 99.55% specificity for other rhythms. Results shows that using t-f data representations to feed classifiers provide superior performance values than the feature selection strategies used in previous works. It opens the door to be used in any other detection applications. Copyright © 2017 Elsevier B.V. All rights reserved.
Aras, Dursun; Topaloglu, Serkan; Cay, Serkan; Ozeke, Ozcan; Cagirci, Goksel; Canpolat, Ugur
We report a case of a 69-year-old male with non-ischemic cardiomyopathy, having drug- and antitachycardia pacing-refractory ventricular tachycardia resulted in multiple ICD shocks. The sustained and intractable ventricular arrhythmia was mapped and ablated with the aid of the three-dimensional electroanatomic mapping system, initially performed but unsuccessful from the endocardial site then performed successfully from the epicardial site via the coronary sinus. PMID:24669109
Ueoka, Akira; Morita, Hiroshi; Watanabe, Atsuyuki; Nakagawa, Koji; Nishii, Nobuhiro; Nagase, Satoshi; Ohe, Tohru; Ito, Hiroshi
Clinical and experimental studies have shown the existence of an arrhythmogenic substrate in the right ventricular outflow tract (RVOT) in patients with Brugada syndrome (BrS). To evaluate the importance of the RVOT, we evaluated the activation pattern of induced ventricular tachyarrhythmias using body surface mapping (BSM) in patients with BrS. We examined 14 patients with BrS in whom ventricular tachyarrhythmias were induced by programmed electrical stimulation. The 87-lead BSM was recorded during induced ventricular tachyarrhythmias, and an activation map and an isopotential map of QRS complexes every 5 ms were constructed to evaluate the activation pattern of ventricular tachyarrhythmias. BSM during 20 episodes of ventricular tachyarrhythmias induced at the RVOT showed that repetitive excitation was generated at the RVOT and propagated to the inferior RV and left ventricle, and then returned to the RVOT. Polymorphic QRS change during ventricular tachyarrhythmias was associated with migration of the earliest activation site and rotor. BSM during 4 episodes of ventricular fibrillation (VF) showed that the excitation front moved randomly with formation of multiple wavefronts. Programmed stimulation initiated repetitive firing from the RVOT. Migration and competition of the earliest activation site and rotor and local conduction delay changed the QRS morphology. Degeneration of the reentrant circuit into multiple wavefronts resulted in VF. (Circ J 2016; 80: 1734-1743).
Wang, Lei; Fahimian, Benjamin; Soltys, Scott G; Zei, Paul; Lo, Anthony; Gardner, Edward A; Maguire, Patrick J; Loo, Billy W
The first stereotactic arrhythmia radioablation (STAR) of ventricular tachycardia (VT) was delivered at Stanford on a robotic radiosurgery system (CyberKnife® G4) in 2012. The results warranted further investigation of this treatment. Here we compare dosimetrically three possible treatment delivery platforms for STAR. The anatomy and target volume of the first treated patient were used for this study. A dose of 25 Gy in one fraction was prescribed to the planning target volume (PTV). Treatment plans were created on three treatment platforms: CyberKnife® G4 system with Iris collimator (Multiplan, V. 4.6)(Plan #1), CyberKnife® M6 system with InCise 2(TM) multileaf collimator (Multiplan V. 5.3)(Plan #2) and Varian TrueBeam(TM) STx with HD 120(TM) MLC and 10MV flattening filter free (FFF) beam (Eclipse planning system, V.11) (Plan #3 coplanar and #4 noncoplanar VMAT plans). The four plans were compared by prescription isodose line, plan conformity index, dose gradient, as well as dose to the nearby critical structures. To assess the delivery efficiency, planned monitor units (MU) and estimated treatment time were evaluated. Plans #1-4 delivered 25 Gy to the PTV to the 75.0%, 83.0%, 84.3%, and 84.9% isodose lines and with conformity indices of 1.19, 1.16, 1.05, and 1.05, respectively. The dose gradients for plans #1-4 were 3.62, 3.42, 3.93, and 3.73 with the CyberKnife® MLC plan (Plan #2) the best, and the TrueBeam(TM) STx co-planar plan (Plan #3) the worst. The dose to nearby critical structures (lung, stomach, bowel, and esophagus) were all well within tolerance. The MUs for plans #1-4 were 27671, 16522, 6275, and 6004 for an estimated total-treatment-time/beam-delivery-time of 99/69, 65/35, 37/7, and 56/6 minutes, respectively, under the assumption of 30 minutes pretreatment setup time. For VMAT gated delivery, a 40% duty cycle, 2400MU/minute dose rate, and an extra 10 minutes per extra arc were assumed. Clinically acceptable plans were created with all three
Fahimian, Benjamin; Soltys, Scott G; Zei, Paul; Lo, Anthony; Gardner, Edward A; Maguire, Patrick J; Loo Jr., Billy W
Purpose The first stereotactic arrhythmia radioablation (STAR) of ventricular tachycardia (VT) was delivered at Stanford on a robotic radiosurgery system (CyberKnife® G4) in 2012. The results warranted further investigation of this treatment. Here we compare dosimetrically three possible treatment delivery platforms for STAR. Methods The anatomy and target volume of the first treated patient were used for this study. A dose of 25 Gy in one fraction was prescribed to the planning target volume (PTV). Treatment plans were created on three treatment platforms: CyberKnife® G4 system with Iris collimator (Multiplan, V. 4.6)(Plan #1), CyberKnife® M6 system with InCise 2TM multileaf collimator (Multiplan V. 5.3)(Plan #2) and Varian TrueBeamTM STx with HD 120TM MLC and 10MV flattening filter free (FFF) beam (Eclipse planning system, V.11) (Plan #3 coplanar and #4 noncoplanar VMAT plans). The four plans were compared by prescription isodose line, plan conformity index, dose gradient, as well as dose to the nearby critical structures. To assess the delivery efficiency, planned monitor units (MU) and estimated treatment time were evaluated. Results Plans #1-4 delivered 25 Gy to the PTV to the 75.0%, 83.0%, 84.3%, and 84.9% isodose lines and with conformity indices of 1.19, 1.16, 1.05, and 1.05, respectively. The dose gradients for plans #1-4 were 3.62, 3.42, 3.93, and 3.73 with the CyberKnife® MLC plan (Plan #2) the best, and the TrueBeamTM STx co-planar plan (Plan #3) the worst. The dose to nearby critical structures (lung, stomach, bowel, and esophagus) were all well within tolerance. The MUs for plans #1-4 were 27671, 16522, 6275, and 6004 for an estimated total-treatment-time/beam-delivery-time of 99/69, 65/35, 37/7, and 56/6 minutes, respectively, under the assumption of 30 minutes pretreatment setup time. For VMAT gated delivery, a 40% duty cycle, 2400MU/minute dose rate, and an extra 10 minutes per extra arc were assumed. Conclusion Clinically acceptable plans were
Piers, Sebastiaan R D; Tao, Qian; van Huls van Taxis, Carine F B; Schalij, Martin J; van der Geest, Rob J; Zeppenfeld, Katja
There are limited data on typical arrhythmogenic substrates and associated ventricular tachycardias (VT) in patients with nonischemic cardiomyopathy. The substrate location may have implications for the ablation strategy. Nineteen consecutive patients with nonischemic cardiomyopathy (age 58±14 years, 79% men, left ventricular ejection fraction 41±11%) who underwent contrast-enhanced MRI and VT ablation were included. On the basis of 3-dimensional contrast-enhanced MRI-derived scar reconstructions, 8 patients (42%) had predominant basal anteroseptal scar, 9 patients (47%) had predominant inferolateral scar, and 2 patients (11%) had other scar types. Three distinct VT morphologies (≥1 of 3 inducible in 16/19 patients) were associated with underlying scar type. In 9 patients with anteroseptal scar-related VT (8/9 predominant scar, 1/9 nonpredominant), ablation target sites (defined as sites with ≥11/12 pacemap, concealed entrainment or VT termination during ablation) were located in the aortic root and/or anteroseptal left ventricular endocardium in 8 patients (89%) and in the anterior cardiac vein in 1 patient (11%), with additional target sites at the right ventricular septum in 2 patients (22%) and at the epicardium in 1 patient (11%). In contrast, in 8 patients with predominant inferolateral scar-related VT, target sites were located at the epicardium in 5 patients (63%) and in the endocardial inferolateral left ventricle in 3 patients (37%). Two typical scar patterns (anteroseptal and inferolateral) account for 89% of arrhythmogenic substrates in patients with nonischemic cardiomyopathy. Three distinct VT morphologies are highly suggestive of the presence of these scars. Anteroseptal scars were, in general, most effectively approached from the aortic root or anteroseptal left ventricular endocardium, whereas inferolateral scars frequently required an epicardial approach.
Sellers, T.D.; Beller, G.A.; Gibson, R.S.; Watson, D.D.; DiMarco, J.P.
The prevalence of exercise-induced ischemia was determined by thallium-201 (TI-201) scintigraphic criteria in patients with ventricular tachycardia (VT) or ventricular fibrillation (VF) inducible by programmed electrical stimulation. Thirty-eight patients (age 57 +/- 19 years), of whom 87% had angiographic coronary artery disease, underwent quantitative TI-201 exercise scintigraphy within 14 days of invasive electrophysiologic testing. The mean rest ejection fraction was 38 +/- 9%. Eighty percent of patients had 1 or more regions with akinetic or dyskinetic wall motion. Thallium-201 scan segments were scored as normal or containing redistribution defects or mild or severe persistent defects. Only 4 patients (10%) had only redistribution defects and 9 (24%) had both redistribution defects and persistent defects; 32 of 38 patients (84%) had 1 or more persistent defects, of which 26 had at least 1 severe, persistent defect (more than 50% reduction in TI-201 activity). Patients with and without exercise-induced VT had a similar prevalence of redistribution. Redistribution defect prevalence was similar in patients with polymorphic VT (3 of 13) and monomorphic VT (10 of 25) during programmed electrical stimulation (difference not significant). Thus, patients with VT or VF induced by programmed ventricular stimulation have extensive TI-201 scintigraphic abnormalities on exercise scintigrams, predominantly those suggesting scar, with associated severe regional wall motion abnormalities at rest.
Janardhan, Ajit H; Li, Wenwen; Fedorov, Vadim V; Yeung, Michael; Wallendorf, Michael J; Schuessler, Richard B; Efimov, Igor R
The authors sought to develop a low-energy electrotherapy that terminates ventricular tachycardia (VT) when antitachycardia pacing (ATP) fails. High-energy implantable cardioverter-defibrillator (ICD) shocks are associated with device failure, significant morbidity, and increased mortality. A low-energy alternative to ICD shocks is desirable. Myocardial infarction was created in 25 dogs. Sustained, monomorphic VT was induced by programmed stimulation. Defibrillation electrodes were placed in the right ventricular apex, and coronary sinus and left ventricular epicardium. If ATP failed to terminate sustained VT, the defibrillation thresholds (DFTs) of standard versus experimental electrotherapies were measured. Sustained VT ranged from 276 to 438 beats/min (mean 339 beats/min). The right ventricular-coronary sinus shock vector had lower impedance than the right ventricular-left ventricular patch (54.4 ± 18.1 Ω versus 109.8 ± 16.9 Ω; p < 0.001). A single shock required between 0.3 ± 0.2 J to 5.9 ± 2.5 J (mean 2.64 ± 3.22 J; p = 0.008) to terminate VT, and varied depending upon the phase of the VT cycle in which it was delivered. By contrast, multiple shocks delivered within 1 VT cycle length were not phase dependent and achieved lower DFT compared with a single shock (0.13 ± 0.09 J for 3 shocks, 0.08 ± 0.04 J for 5 shocks, and 0.09 ± 0.07 J for 7 shocks; p < 0.001). Finally, a multistage electrotherapy (MSE) achieved significantly lower DFT compared with a single biphasic shock (0.03 ± 0.05 J versus 2.37 ± 1.20 J; respectively, p < 0.001). At a peak shock amplitude of 20 V, MSE achieved 91.3% of terminations versus 10.5% for a biphasic shock (p < 0.001). MSE achieved a major reduction in DFT compared with a single biphasic shock for ATP-refractory monomorphic VT, and represents a novel electrotherapy to reduce high-energy ICD shocks. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
D'Ovidio, Cristian; Carnevale, Aldo; Grassi, Vincenzo M; Rosato, Enrica; Del Olmo, Bernat; Coll, Monica; Campuzano, Oscar; Iglesias, Anna; Brugada, Ramon; Oliva, Antonio
This paper discusses the case of a young boy who died suddenly during a football match. The victim's personal and family medical histories were negative for cardiac events. He had undergone a cardiological investigation some months before his death, enabling him to participate in competitive sports. Only post-mortem molecular analysis allowed for a clearer determination of the most plausible cause of death, which was identified as inherited arrhythmogenic heart disease, known as catecholaminergic polymorphic ventricular tachycardia. It was possible to detect a novel, previously undescribed, variant in the RYR2 gene. This case report highlights the importance of a meaningful forensic multidisciplinary investigation in such cases, and also discusses possible medical malpractice claims.
Podrid, Philip J.
Sustained ventricular tachyarrythmias are uncommon in young people, and underlying heart disease is usually present. This article presents a case study of a 24-year-old male athlete with arrhythmogenic right ventricular dysplasia and points out the value of combinations of drugs versus the use of a single agent. (MT)
Podrid, Philip J.
Sustained ventricular tachyarrythmias are uncommon in young people, and underlying heart disease is usually present. This article presents a case study of a 24-year-old male athlete with arrhythmogenic right ventricular dysplasia and points out the value of combinations of drugs versus the use of a single agent. (MT)
Yamashita, Seigo; Sacher, Frédéric; Mahida, Saagar; Berte, Benjamin; Lim, Han S; Komatsu, Yuki; Amraoui, Sana; Denis, Arnaud; Derval, Nicolas; Laurent, François; Montaudon, Michel; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre; Cochet, Hubert
Epicardial ventricular tachycardia (VT) ablation is associated with risks of coronary artery (CA) and phrenic nerve (PN) injury. We investigated the role of multidetector computed tomography in visualizing CA and PN during VT ablation. Ninety-five consecutive patients (86 men; age, 57 ± 15) with VT underwent cardiac multidetector computed tomography. The PN detection rate and anatomic variability were analyzed. In 49 patients undergoing epicardial mapping, real-time multidetector computed tomographic integration was used to display CAs/PN locations in 3-dimensional mapping systems. Elimination of local abnormal ventricular activities (LAVAs) was used as ablation end point. The distribution of CAs/PN with respect to LAVA was analyzed and compared between VT etiologies. Multidetector computed tomography detected PN in 81 patients (85%). Epicardial LAVAs were observed in 44 of 49 patients (15 ischemic cardiomyopathy, 15 nonischemic cardiomyopathy, and 14 arrhythmogenic right ventricular cardiomyopathy) with a mean of 35 ± 37 LAVA points/patient. LAVAs were located within 1 cm from CAs and PN in 35 (80%) and 18 (37%) patients, respectively. The prevalence of LAVA adjacent to CAs was higher in nonischemic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy than in ischemic cardiomyopathy (100% versus 86% versus 53%; P < 0.01). The prevalence of LAVAs adjacent to PN was higher in nonischemic cardiomyopathy than in ischemic cardiomyopathy (93% versus 27%; P < 0.001). Epicardial ablation was performed in 37 patients (76%). Epicardial LAVAs could not be eliminated because of the proximity to CAs or PN in 8 patients (18%). The epicardial electrophysiological VT substrate is often close to CAs and PN in patients with nonischemic cardiomyopathy. High-resolution image integration is potentially useful to minimize risks of PN and CA injury during epicardial VT ablation. © 2015 American Heart Association, Inc.
Makarov, L M; Kuryleva, T A; Chuprova, S N
To elucidate clinical and electrocardiographical characteristics of children and adolescents with malignant idiopathic polymorphic ventricular tachycardia. Patients aged 6-14 years (n=16) with polymorphic bidirectional tachycardia registered either on standard 12-lead ECG (n=6), or during treadmill exercise test (n=2) and Holter ECG monitoring (n=8). None of the patients had overt heart or coronary artery disease, chronic extracardiac pathology or electrolyte disturbances. There was no QT, QT(s) prolongations, or ST segment elevations in right precordial leads. Eleven patients (68.8%) had shortening of PR interval -110 ms without signs of Wolf-Parkinson-White syndrome. All patients with shortened PR had history of syncopal states (9.1+/-9.2 per year), 4 patients (36.4%) had family history of sudden death in young age. Among patients without PR shortening 2 (40%) had history of syncopal attacks (1-2 or 0.6+/-0.89 per year). All patients with short PR had bradycardia while in sinus rhythm (55.5+/-9.1 bpm compared with 78.1+/-2.8 bpm in patients without PR shortening). Shortened PR and bradycardia were found to be associated with frequent attacks of syncope in this series of children with polymorphic tachycardia. Therefore combination of short PR, bradycardia and polymorphic ventricular tachycardia was suggested to comprise clinico-electrocardiographic syndrome with high risk of malignant ventricular tachyarrhythmia and sudden death.
Fishberger, Steven B; Asnes, Jeremy D; Rollinson, Nancy L; Cleman, Michael W
Late sequelea following a Mustard operation for transposition of the great arteries (TGA) include atrial arrhythmias and dysfunction of the systemic right ventricle. Catheter mapping and ablation of atrial tachycardia in the setting of significant right ventricular dysfunction may result in hemodynamic compromise. We report the novel use of the Impella percutaneous microaxial flow pump to support cardiac output in an adult patient with a Mustard operation for TGA who experienced a cardiac arrest during a prior ablation attempt. The Impella device was placed via a retrograde approach across the aortic valve into the right ventricle providing hemodynamic stability for successful mapping and ablation of intra-atrial reentrant tachycardia.
Varenne, A; Blanc, P; Camous, J P; Grangier, L; Morand, P
In order to study abnormal post-QRS micropotentials, so called late potentials, and to determine their frequency in post myocardial infarction ventricular tachycardia (VT), high amplification electrocardiogrammes were recorded in 180 patients classified in 3 different groups: Group A comprising 36 patients who developed sustained VT after myocardial infarction; Group B comprising 124 patients with myocardial infarction uncomplicated by VT. This group was subdivided into subgroup B1 (retrospective study of 35 patients with chronic myocardial infarction, dating on average 10 months--range 7 days to 8 years) and subgroup B2 (prospective study of 89 patients investigated on the 7th and 60th days after infarction); Group C comprising 20 young, normal control subjects. Using computer assisted high amplification electrocardiography, all patients underwent at least 3 successive recordings of the following parameters: averaging 100 cycles; sampling: 1 kHz; band pass 20-300 Hz and 80-300 Hz; gain setting 10,000 and 25,000. Late potentials usually appears, after the end of the S wave, as high frequency oscillations with an amplitude (10 to 20 microV) significantly greater than that of the background noise. Our recordings also showed: the frequent presence, especially in intraventricular blocks, of fragmentation of the end of the R wave and of the S wave or terminal potentials; the presence of an abnormal giant low frequency high amplitude wave (40 to 80 microV) in 5 patients with a large left ventricular aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)
Jung, Christian B; Moretti, Alessandra; Mederos y Schnitzler, Michael; Iop, Laura; Storch, Ursula; Bellin, Milena; Dorn, Tatjana; Ruppenthal, Sandra; Pfeiffer, Sarah; Goedel, Alexander; Dirschinger, Ralf J; Seyfarth, Melchior; Lam, Jason T; Sinnecker, Daniel; Gudermann, Thomas; Lipp, Peter; Laugwitz, Karl-Ludwig
Coordinated release of calcium (Ca2+) from the sarcoplasmic reticulum (SR) through cardiac ryanodine receptor (RYR2) channels is essential for cardiomyocyte function. In catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited disease characterized by stress-induced ventricular arrhythmias in young patients with structurally normal hearts, autosomal dominant mutations in RYR2 or recessive mutations in calsequestrin lead to aberrant diastolic Ca2+ release from the SR causing arrhythmogenic delayed after depolarizations (DADs). Here, we report the generation of induced pluripotent stem cells (iPSCs) from a CPVT patient carrying a novel RYR2 S406L mutation. In patient iPSC-derived cardiomyocytes, catecholaminergic stress led to elevated diastolic Ca2+ concentrations, a reduced SR Ca2+ content and an increased susceptibility to DADs and arrhythmia as compared to control myocytes. This was due to increased frequency and duration of elementary Ca2+ release events (Ca2+ sparks). Dantrolene, a drug effective on malignant hyperthermia, restored normal Ca2+ spark properties and rescued the arrhythmogenic phenotype. This suggests defective inter-domain interactions within the RYR2 channel as the pathomechanism of the S406L mutation. Our work provides a new in vitro model to study the pathogenesis of human cardiac arrhythmias and develop novel therapies for CPVT. PMID:22174035
Mathuria, Nilesh; Wu, Geru; Rojas-Delgado, Francia; Shuraih, Mossaab; Razavi, Mehdi; Civitello, Andrew; Simpson, Leo; Silva, Guilherme; Wang, Suwei; Elayda, MacArthur; Kantharia, Bharat; Singh, Steve; Frazier, O H; Cheng, Jie
Patient selection and timing of percutaneous left ventricular assist device (pLVAD) insertion for maximal benefit during ventricular tachycardia (VT) ablation is not well defined. We aimed to assess the outcomes of pre-emptive and rescue use of pLVAD during VT ablation in patients with ischemic and non-ischemic cardiomyopathy. Between January 2009 and October 2011, 93 patients underwent VT ablation. Three groups were compared: (1) Rescue group (n = 12)-patients who required emergent pLVAD insertion due to hemodynamic collapse during VT ablation, (2) Pre-emptive group (n = 24)-patients who had pre-ablation pLVAD insertion, and (3) Non-pLVAD group (n = 57)-patients who did not undergo pLVAD insertion. Procedural outcomes including 30-day mortality were compared. Thirty-day mortality was higher in the Rescue group compared to the Pre-emptive group (58 vs. 4 %, p = 0.003) and non-pLVAD (58 vs. 3 %, p = 0.001) group. There was no significant difference in 30-day mortality or long-term freedom of VT between the pre-emptive and non-pLVAD groups. Despite rescue pLVAD insertion, hemodynamic collapse during VT ablation is associated with a persistently high 30-day mortality. Further studies are warranted to predict hemodynamic collapse and to refine the role of pLVAD in this setting.
Petrucci, Ettore; Sarzi Braga, Simona; Balian, Vruyr; Pedretti, Roberto F E
ICD shocks occurring in conscious patients (as in the case of well-tolerated arrhythmias, electromagnetic interference, or oversensing) have a deleterious impact on the quality of life. We evaluated if a hemodynamic parameter, calculated from the right ventricular pressure (RVP) or systemic arterial pressure (AP) signals, could predict early clinical symptoms of cerebral hypoperfusion during induced ventricular tachycardias (VTs). We analyzed 42 tolerated (no symptoms) and 30 untolerated (syncope or severe symptoms within 30 seconds from the onset) VTs, induced during electrophysiological study. The cycle length (CL) and the hemodynamic data (mean AP and RVP, arterial pulse pressure and RV pulse pressure, and maximum AP and RVP dP/dT) were automatically sampled in two VT epochs: the "detection" window, from beat 24 to 32, and the "preintervention" window, immediately before the first therapeutic attempt. Although the CL and all the hemodynamic parameters (expressed as % change versus pre-VT values) were significantly lower in untolerated versus tolerated VTs both at detection and preintervention (with the exception of the mean RVP which progressively increased in both groups), ROC analysis demonstrated that only the preintervention RV pulse pressure showed no overlap between groups, providing 100% sensitivity and positive predictive value. The reduction of the RV pulse pressure is a better predictor of early cerebral symptoms than CL or other hemodynamic indexes during induced VTs. Since long-term RVP monitoring is feasible, this parameter could be incorporated into ICDs decisional path, in the perspective of reducing unnecessary, painful shocks.
Domingo, Diana; Neco, Patricia; Fernández-Pons, Elena; Zissimopoulos, Spyros; Molina, Pilar; Olagüe, José; Suárez-Mier, M Paz; Lai, F Anthony; Gómez, Ana M; Zorio, Esther
Catecholaminergic polymorphic ventricular tachycardia is a malignant disease, due to mutations in proteins controlling Ca(2+) homeostasis. While the phenotype is characterized by polymorphic ventricular arrhythmias under stress, supraventricular arrhythmias may occur and are not fully characterized. Twenty-five relatives from a Spanish family with several sudden deaths were evaluated with electrocardiogram, exercise testing, and optional epinephrine challenge. Selective RyR2 sequencing in an affected individual and cascade screening in the rest of the family was offered. The RyR2(R420Q) mutation was generated in HEK-293 cells using site-directed mutagenesis to conduct in vitro functional studies. The exercise testing unmasked catecholaminergic polymorphic ventricular tachycardia in 8 relatives (sensitivity = 89%; positive predictive value = 100%; negative predictive value = 93%), all of them carrying the heterozygous RyR2(R420Q) mutation, which was also present in the proband and a young girl without exercise testing, a 91% penetrance at the end of the follow-up. Remarkably, sinus bradycardia, atrial and junctional arrhythmias, and/or giant post-effort U-waves were identified in patients. Upon permeabilization and in intact cells, the RyR2(R420Q) expressing cells showed a smaller peak of Ca(2+) release than RyR2 wild-type cells. However, at physiologic intracellular Ca(2+) concentration, equivalent to the diastolic cytosolic concentration, the RyR2(R420Q) released more Ca(2+) and oscillated faster than RyR2 wild-type cells. The missense RyR2(R420Q) mutation was identified in the N-terminus of the RyR2 gene in this highly symptomatic family. Remarkably, this mutation is associated with sinus bradycardia, atrial and junctional arrhythmias, and giant U-waves. Collectively, functional heterologous expression studies suggest that the RyR2(R420Q) behaves as an aberrant channel, as a loss- or gain-of-function mutation depending on cytosolic intracellular Ca(2
Preininger, Marcela K.; Jha, Rajneesh; Maxwell, Joshua T.; Wu, Qingling; Singh, Monalisa; Dalal, Aarti; Mceachin, Zachary T.; Rossoll, Wilfried; Hales, Chadwick M.; Fischbach, Peter S.; Wagner, Mary B.
ABSTRACT Although β-blockers can be used to eliminate stress-induced ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), this treatment is unsuccessful in ∼25% of cases. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) generated from these patients have potential for use in investigating the phenomenon, but it remains unknown whether they can recapitulate patient-specific drug responses to β-blockers. This study assessed whether the inadequacy of β-blocker therapy in an individual can be observed in vitro using patient-derived CPVT iPSC-CMs. An individual with CPVT harboring a novel mutation in the type 2 cardiac ryanodine receptor (RyR2) was identified whose persistent ventricular arrhythmias during β-blockade with nadolol were abolished during flecainide treatment. iPSC-CMs generated from this patient and two control individuals expressed comparable levels of excitation-contraction genes, but assessment of the sarcoplasmic reticulum Ca2+ leak and load relationship revealed intracellular Ca2+ homeostasis was altered in the CPVT iPSC-CMs. β-adrenergic stimulation potentiated spontaneous Ca2+ waves and unduly frequent, large and prolonged Ca2+ sparks in CPVT compared with control iPSC-CMs, validating the disease phenotype. Pursuant to the patient's in vivo responses, nadolol treatment during β-adrenergic stimulation achieved negligible reduction of Ca2+ wave frequency and failed to rescue Ca2+ spark defects in CPVT iPSC-CMs. In contrast, flecainide reduced both frequency and amplitude of Ca2+ waves and restored the frequency, width and duration of Ca2+ sparks to baseline levels. By recapitulating the improved response of an individual with CPVT to flecainide compared with β-blocker therapy in vitro, these data provide new evidence that iPSC-CMs can capture basic components of patient-specific drug responses. PMID:27491078
Kapel, Gijsbert F L; Reichlin, Tobias; Wijnmaalen, Adrianus P; Tedrow, Usha B; Piers, Sebastiaan R D; Schalij, Martin J; Hazekamp, Mark G; Jongbloed, Monique R M; Stevenson, William G; Zeppenfeld, Katja
Radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in repaired Tetralogy of Fallot focuses on isthmuses in the right ventricle but may be hampered by hypertrophied myocardium or prosthetic material. These patients may benefit from ablation at the left side of the ventricular septum. Records from 28 consecutive repaired Tetralogy of Fallot patients from 2 centers who underwent VT ablation were reviewed. Ablation targeted anatomic isthmuses containing VT re-entry circuits, which were identified by 3-dimensional substrate, pace, and entrainment mapping. A left-sided approach was considered beneficial if (1) right-sided RFCA failed, (2) part of the circuit was mapped to the left side, and (3) left-sided RFCA resulted in isthmus transection and prevention of VT induction. In 4 of 28 patients (52±13 years; 75% men), inducible for 1.5 (quartiles, 1.0 - 2.0) VTs (335±58 ms), left-sided RFCA was performed. In 3 patients, RFCA at aortic sites terminated VT related to a septal isthmus and prevented reinduction. In 1 patient, with prior biventricular implantable cardioverter-defibrillator, diastolic activity was recorded at the left side of the septum in proximity to the His-bundle. RFCA prevented VT reinduction with anticipated complete atrioventricular block. The left-sided approach resulted in complete procedural success (transection of anatomic isthmus and noninducibility) and freedom of VT recurrence during follow-up (20±15 months) in all patients. Right-sided RFCA failure was likely because of septal hypertrophy in 2, overlying pulmonary homograft in 1, and overlying ventricular septal defect patch in 1. Left-sided RFCA for VTs dependent on septal anatomic isthmuses improves ablation outcome in repaired Tetralogy of Fallot. © 2014 American Heart Association, Inc.
Piers, Sebastiaan R D; Silva, Marta de Riva; Kapel, Gijsbert F L; Trines, Serge A; Schalij, Martin J; Zeppenfeld, Katja
Specific 12-lead ECG criteria have been reported to predict an epicardial site of origin (SoO) of induced ventricular tachycardias (VTs) in left ventricular nonischemic cardiomyopathy. The purpose of this study was to (1) determine the value of ECG criteria to predict an epicardial SoO of clinically documented VTs, (2) analyze the effect of VT cycle length (CL) and antiarrhythmic drugs on the accuracy of ECG criteria, and (3) assess interobserver variability. In 36 consecutive patients with nonischemic left ventricular cardiomyopathy (age 58 ± 16 years, 75% male) who underwent combined endocardial/epicardial VT ablation, all clinically documented and induced right bundle branch block VTs were analyzed for previously reported ECG criteria to determine the SoO, as defined by ≥11/12 pace-map, concealed entrainment, and/or VT termination during ablation. In 21 patients with clinically documented (25 mm/s) right bundle branch block VT, none of the ECG criteria differentiated between patients with and those without an epicardial SoO. In induced VTs (100 mm/s), 2 of 4 interval criteria differentiated between an endocardial and epicardial SoO for slow VTs (CL >350 ms) and 2 of 4 criteria in patients on amiodarone, but none for fast VTs (CL ≤350 ms) or patients off amiodarone. The Q wave in lead I was the most accurate criterion for an epicardial SoO (sensitivity 88%, specificity 80%). In both clinically documented and induced VTs, interobserver agreement was poor for pseudodelta wave and moderate for other criteria. When applied to clinically documented VTs, no ECG criterion could differentiate between patients with and those without an epicardial SoO. Published interval-based ECG criteria do not apply to fast VTs and patients off amiodarone. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Berte, Benjamin; Sacher, Frederic; Cochet, Hubert; Mahida, Saagar; Yamashita, Seigo; Lim, Han; Denis, Arnaud; Derval, Nicolas; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre
Nonischemic cardiomyopathy is a heterogeneous condition providing a favorable substrate for ventricular tachycardia (VT). The purpose of this study is to further characterize the substrate in a subset of postmyocarditis patients with epicardial-only scar. Twelve postmyocarditis patients (11 male, 49 ± 14 years, left ventricular ejection fraction 49 ± 12%) with VT and epicardial-only scar were included for analysis comparing automatic high-amplitude normal activity (HANA) maps to manually adjusted maps of based on local abnormal ventricular activity (LAVA) electrograms when present. A combined endocardial (endo) and epicardial (epi) approach was used in 11/12 with usual bipolar/unipolar voltage thresholds and analyzed using image integration. A delayed enhancement MRI scar area of 52 cm(2) (38, 59) and multidetector CT wall thinning area of 18 cm(2) (14, 35) was found. Bipolar voltage substrate mapping (160 points [101, 239] endo, 553 points [232, 713] epi and LAVA were found only epicardially [443 LAVA points] in all) illustrated a low-voltage area of HANA: 1 cm(2) (0, 10) endo, 25 cm(2) (22, 39) epi and LAVA: 1 cm(2) (0, 10) endo, 39 cm(2) (28, 51) epi. Manual maps performed better than automatic maps for delineating low-voltage area with a higher overlap with scar area on delayed enhancement magnetic resonance imaging (DE-MRI; 76% [66, 94] vs. 45% [35, 62]; P = 0.04). In addition, manual voltage maps also showed a higher overlap with location of LAVA (LAVA in normal voltage area: 3% [0, 9] vs. 35% [32, 41]; P < 0.05). In postmyocarditis patients with epicardial-only scar, automatic voltage mapping may miss or minimize the electrical VT substrate. DE-MRI and manual LAVA-based voltage mapping are necessary to optimize scar delineation. Epicardial access is critical for mapping and ablation in this condition. © 2014 Wiley Periodicals, Inc.
Gökoğlan, Yalçın; Mohanty, Sanghamitra; Gianni, Carola; Santangeli, Pasquale; Trivedi, Chintan; Güneş, Mahmut F; Bai, Rong; Al-Ahmad, Amin; Gallinghouse, G Joseph; Horton, Rodney; Hranitzky, Patrick M; Sanchez, Javier E; Beheiry, Salwa; Hongo, Richard; Lakkireddy, Dhanunjaya; Reddy, Madhu; Schweikert, Robert A; Dello Russo, Antonio; Casella, Michela; Tondo, Claudio; Burkhardt, J David; Themistoclakis, Sakis; Di Biase, Luigi; Natale, Andrea
Scar homogenization improves long-term ventricular arrhythmia-free survival compared with standard limited-substrate ablation in patients with post-infarction ventricular tachycardia (VT). Whether such benefit extends to patients with nonischemic cardiomyopathy and scar-related VT is unclear. The aim of this study was to assess the long-term efficacy of an endoepicardial scar homogenization approach compared with standard ablation in this population. Consecutive patients with dilated nonischemic cardiomyopathy (n = 93), scar-related VTs, and evidence of low-voltage regions on the basis of pre-defined criteria on electroanatomic mapping (i.e., bipolar voltage <1.5 mV) underwent either standard VT ablation (group 1 [n = 57]) or endoepicardial ablation of all abnormal potentials within the electroanatomic scar (group 2 [n = 36]). Acute procedural success was defined as noninducibility of any VT at the end of the procedure; long-term success was defined as freedom from any ventricular arrhythmia at follow-up. Acute procedural success rates were 69.4% and 42.1% after scar homogenization and standard ablation, respectively (p = 0.01). During a mean follow-up period of 14 ± 2 months, single-procedure success rates were 63.9% after scar homogenization and 38.6% after standard ablation (p = 0.031). After multivariate analysis, scar homogenization and left ventricular ejection fraction were predictors of long-term success. During follow-up, the rehospitalization rate was significantly lower in the scar homogenization group (p = 0.035). In patients with dilated nonischemic cardiomyopathy, scar-related VT, and evidence of low-voltage regions on electroanatomic mapping, endoepicardial homogenization of the scar significantly increased freedom from any recurrent ventricular arrhythmia compared with a standard limited-substrate ablation. However, the success rate with this approach appeared to be lower than previously reported with ischemic cardiomyopathy, presumably
Reichlin, Tobias; Lockwood, Stephen J; Conrad, Michael J; Nof, Eyal; Michaud, Gregory F; John, Roy M; Epstein, Laurence M; Stevenson, William G; Jarolim, Petr
Radiofrequency ablation results in intentional cardiac injury. We aimed to assess the kinetics of cardiac injury as measured by cardiac troponin release following ventricular ablation and atrial ablation. Patients undergoing ablation for ventricular tachycardia (VT) with structural heart disease (19 patients) or atrial fibrillation (AF, 24 patients) were prospectively enrolled. High-sensitivity cardiac troponin T (hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) were measured before ablation as well as 30 min, 60 min, 90 min, 120 min, 4 h, 8 h, and 24 h after applying the first ablation lesion. Median ablation time, power used, and energy delivered were 28 min, 39 W, and 69,713 J in VT ablations and 55 min, 29 W, and 95,425 J in AF ablations, respectively. Release of hs-cTnT occurred promptly with both, but reached greater levels earlier for ventricular compared to atrial ablation (hs-cTnT after 30 min 191 vs. 31 ng/l, after 1 h 467 vs. 80 ng/l; hs-cTnI after 30 min 132 vs. 30 ng/l, after 1 h 331 vs. 76 ng/l; p < 0.001 for all comparisons). After 24 h, levels were similar (hs-cTnT 1325 vs. 1303 ng/l, p = 0.92; hs-cTnI 2165 vs. 1996 ng/l, p = 0.55). Levels of hs-cTnT after 24 h correlated well with the energy delivered in AF ablations (r = 0.81 and r = 0.75, p < 0.001), but not in VT ablations (r = 0.35 and r = 0.44, p = ns). Evidence of cardiac injury as indicated by the release of hs-cTnT and hs-cTnI occurs early with atrial and ventricular ablation. Higher early levels are observed in ventricular ablations, but levels are similar after 24 h. The extent of total troponin release seems to correlate well with the amount of energy delivered in AF ablations, but not in VT ablations.
The Different Substrate Characteristics of Arrhythmogenic Triggers in Idiopathic Right Ventricular Outflow Tract Tachycardia and Arrhythmogenic Right Ventricular Dysplasia: New Insight from Noncontact Mapping
Lin, Yenn-Jiang; Higa, Satoshi; Yagi, Nobumori; Chang, Shih-Lin; Lo, Li-Wei; Chung, Fa-Po; Liao, Jo-Nan; Huang, Yen-Chang; Chan, Chao-Shun; Huang, Hung-Kai; Hu, Yu-Feng; Tsao, Hsuan-Ming; Chen, Shih-Ann
Background The aim of this study was to investigate the different substrate characteristics of repetitive premature ventricular complexed (PVC) trigger sites by the non-contact mapping (NCM). Methods Thirty-five consecutive patients, including 14 with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) and 21 with idiopathic right ventricular outflow tract tachycardia (RVOT VT), were enrolled for electrophysiological study and catheter ablation guided by the NCM. Substrate and electrogram (Eg) characteristics of the earliest activation (EA) and breakout (BO) sites of PVCs were investigated, and these were confirmed by successful PVC elimination. Results Overall 35 dominant focal PVCs were identified. PVCs arose from the focal origins with preferential conduction, breakout, and spread to the whole right ventricle. The conduction time and distance from EA to BO site were both longer in the ARVC than the RVOT group. The conduction velocity was similar between the 2 groups. The negative deflection of local unipolar Eg at the EA site (EA slope3,5,10ms values) was steeper in the RVOT, compared to ARVC patients. The PVCs of ARVC occurred in the diseased substrate in the ARVC patients. More radiofrequency applications were required to eliminate the triggers in ARVC patients. Conclusions/Interpretation The substrate characteristics of PVC trigger may help to differentiate between idiopathic RVOT VT and ARVC. The slowing and slurred QS unipolar electrograms and longer distance from EA to BO in RVOT endocardium suggest that the triggers of ARVC may originate from mid- or sub-epicardial myocardium. More extensive ablation to the trigger site was required in order to create deeper lesions for a successful outcome. PMID:26488594
Kumar, Saurabh; Baldinger, Samuel H; Kapur, Sunil; Romero, Jorge; Mehta, Nishaki K; Mahida, Saagar; Fujii, Akira; Tedrow, Usha B; Stevenson, William G
Right ventricular (RV)-scar related ventricular tachycardia (VT) is often due to arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) or cardiac sarcoidosis (CS), but some patients whose clinical course has not been described do not fulfill diagnostic criteria for these diseases. We sought to characterize the electrophysiologic substrate and catheter ablation outcomes of such patients, termed RV cardiomyopathy of unknown source (RCUS). Data of 100 consecutive patients who presented with RV cardiomyopathy and/or RV-related VT for ablation was reviewed (51 ARVC/D, 22 CS; 27 RCUS). Compared to ARVC/D, RCUS patients were older (P = 0.001), less commonly had RV dilatation (P = 0.001) or dysfunction (P = 0.01) and fragmented QRS, parietal block, and T wave inversion. Compared to CS, R-CUS patients had less severe LV dysfunction. Extent and distribution of endocardial/epicardial scar and inducible VTs in RCUS patients were comparable with ARVC/D and CS patients. At a median follow-up of 23 months, RCUS patients had more favorable VT-free survival (RCUS 71%, ARVC/D 60%, CS 41%, P = 0.03) and survival free of death or cardiac transplant (RCUS 92%, ARVC/D 92%, CS 62%, P = 0.01). No RCUS patients developed new criteria for ARVC/D or CS in follow-up. Up to one-third of patients with RV scar-related VT are not be classifiable as ARVC/D or CS. These patients had a somewhat better prognosis than ARVC/D or sarcoid and did not develop evidence of these diseases during the initial 2 years of follow-up. The extent to which this population is comprised of mild ARVC/D, CS or other diseases is not clear. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.
Dynamics analysis of RR interval behavior and traditional measures of heart rate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heart rate dynamics was better than traditional measures of heart rate variability in differentiating patients with and without life-threatening arrhythmias.
Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.
Dynamics analysis of RR interval behavior and traditional measures of heart rate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heart rate dynamics was better than traditional measures of heart rate variability in differentiating patients with and without life-threatening arrhythmias.
Cardiomyopathy is a heterogeneous group of diseases of heart muscle accompanied with impaired cardiac function. Tachycardia-induced cardiomyopathy (TIC) is caused by prolonged tachycardia leading to dilatation and systolic dysfunction with clinical manifestation of heart failure. This state is reversible after normalization of heart rate. The diagnosis is usually made retrospectively after normalization of heart rate and recovery of left ventricular function (LVF). More than 100 years after the first documented case (described in 1913 in a young patient with atrial fibrillation and symptoms of heart failure ) is still limited knowledge of pathophysiological mechanisms. The most common arrhythmias responsible for the TIC include atrial fibrillation [1,2], atrial flutter , incessant supraventricular tachycardia , ventricular tachycardia (VT)  and frequent ventricular extrasystoles (VES) . TIC detection and therapeutic intervention is crucial considering potential reversibility of tachycardia. Current options of treatment involve drug therapy and surgical or catheter ablation.
Hernández González, D; Iturralde Torres, P; Romero, L; Colín, L; Villarreal, A; González Hermosillo, J A
One case of Wolff-Parkinson-White Syndrome with paroxysmal supraventricular tachycardia related to orthodromic atrioventricular reentry using an accessory pathway for retrograde conduction an a rapidly conducting AV node for anterograde conduction is present. The pharmacological therapy with Digoxin, Propranolol, Quinidine, Disopyramide and Propafenone was not effective. An electrophysiologic study showed a reciprocating tachycardia induced by spontaneous ventricular beats. Both the effective refractory period of the AV node and the anterograde effective refractory period of the accessory pathway were minor or equal to 220 msec which made the control of the arrhythmia difficult. Amiodarone was able to suppress the premature ventricular beats, depress conduction and prolong refractoriness in both, the AV node and accessory pathway to prevent recurrences of atrioventricular reentry. In this patient a false positive test with ajmaline was documented. The electrophysiologic study showed the association of Wolff-Parkinson-White Syndrome with an enhanced atrioventricular nodal-conduction and allowed the selection of an appropriate antiarrhythmic agent.
Nearing, Bruce D.; Wellenius, Gregory A.; Mittleman, Murray A.; Josephson, Mark E.; Burger, Andrew J.; Verrier, Richard L.
Background A critical need exists for reliable warning markers of in-hospital life-threatening arrhythmias. We employed a new quantitative method to track interlead heterogeneity of depolarization and repolarization to detect premonitory changes prior to ventricular tachycardia (VT) in hospitalized patients with acute decompensated heart failure. Methods and Results Ambulatory ECGs (leads V1, V5, and aVF) recorded before initiation of drug therapy from patients enrolled in the Prospective Randomized Evaluation of Cardiac Ectopy with Dobutamine or Nesiritide Therapy (PRECEDENT) trial were analyzed. R-wave and T-wave heterogeneity (RWH, TWH) were assessed by second central moment analysis and T-wave alternans (TWA) by Modified Moving Average analysis. Patients (N=44) studied included those (N = 22) with episodes of VT (≥4 beats at heart rates >100 beats/min) following ≥120 minutes of stable sinus rhythm and age- and sex-matched patients (N=22) without VT. TWA increased from 18.6±2.1μV (baseline, mean ± SEM) to 27.9±4.6μV in lead V5 at 15–30 minutes prior to VT (p<0.05) and remained elevated until the arrhythmia occurred. TWA results in V1 and aVF were similar. RWH and TWH were elevated from 164.1±33.1μV and 134.5±20.6μV (baseline) to 299.8±54.5μV and 239.2±37.0μV at 30–45 minutes prior to VT (p<0.05), respectively, preceding the crescendo in TWA by 15 minutes. Matched patients without VT did not display elevated RWH (185.5±29.4μV) or TWH (157.1±27.2μV) during the 24–hour period. Conclusions This is the first clinical demonstration of the potential utility of tracking depolarization and repolarization heterogeneity to detect crescendos in electrical instability that could forewarn of impending nonsustained ventricular tachycardia. Clinical Trial Registration http://clinicaltrials.gov; NCT00270400. PMID:22157521
Yalin, Kivanc; Golcuk, Ebru; Bilge, Ahmet Kaya; Aksu, Tolga; Buyukbayrak, Hakan; Tiryakioglu, Selma Kenar; Emet, Samim; Adalet, Kamil
Scars causing ventricular tachycardia can extend deep to and beyond bipolar low-voltage areas (LVAs) and they may be a reason for endocardial ablation failure. Analysis of endocardial unipolar voltage maps has been used to detect scar transmurality and epicardial scar. We hypothesized that endocardial unipolar LVA around the overlying bipolar LVA may predict endocardial ablation recurrence in patients with structural heart disease undergoing substrate modification. Twenty consecutive patients with structural heart disease (11 ischaemic and 9 non-ischaemic cardiomyopathy) and undergoing substrate modification due to unmappable ventricular tachycardia (VT) (18 males, 51 ± 11 age, LVEF: 36 ± 7%) were retrospectively reviewed. Bipolar LVA defined as <1.5 mV and unipolar LVA defined as <8.3 mV, respectively, on electro-anatomic mapping system. Peripheral unipolar LVA (pUni-LVA) surrounding bipolar LVA was measured and compared patients with and without VT recurrence at 6-month follow-up period. : Mean unipolar voltage and mean bipolar voltage was 6.26 ± 4.99 and 1.90 ± 2.30 mV, respectively. Bipolar voltage and unipolar voltage in corresponding points were correlated (r = 0.652, P = 0.0001). In all patients, unipolar LVAs were larger than the bipolar LVAs. Bipolar LVA (91.1 ± 93.5 vs. 87.5 ± 47.5 cm(2), P = 0.91) and unipolar LVA (148.1 ± 96.3 vs. 104.7 ± 44.2 cm(2), P = 0.21) were similar in patients with and without VT recurrence, respectively. Peripheral unipolar LVA was significantly larger in patients with VT recurrence than without (57.0 ± 40.4 vs. 17.2 ± 12.9 cm(2), P = 0.01). In patients with structural heart disease and unmappable VT, pUni-LVA surrounding bipolar scar predicts recurrence of VT ablation. The results of this pilot study highlight the importance of intramural/epicardial substrate on endocardial VT ablation outcome. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please
Lu, Hua Rong; Hermans, An N; Gallacher, David J
Terfenadine has been reported to cause cardiac death. Hence, we investigated its pro-arrhythmic potential in various in vitro models. Pro-arrhythmic effects of terfenadine were investigated in rabbit isolated hearts and left ventricular wedge preparations. Also, using whole-cell patch-clamp recording, we examined its effect on the human ether-à-go-go-related gene (hERG) current in HEK293 cells transfected with hERG and on the I(Na) current in rabbit ventricular cells and human atrial myocytes. Terfenadine concentration- and use-dependently inhibited I(Na) in rabbit myocytes and in human atrial myocytes and also inhibited the hERG. In both the rabbit left ventricular wedge and heart preparations, terfenadine at 1 µM only slightly prolonged the QT- and JT-intervals but at 10 µM, it caused a marked widening of the QRS complex, cardiac wavelength shortening, incidences of in-excitability and non-TdP-like ventricular tachycardia/fibrillation (VT/VF) without prolongation of the QT/JT-interval. At 10 µM terfenadine elicited a lower incidence of early afterdepolarizations versus non- Torsades de Pointes (TdP)-like VT/VF (100% incidence), and did not induce TdPs. Although the concentration of terfenadine in the tissue-bath was low, it accumulated within the heart tissue. Our data suggest that: (i) the induction of non-TdP-like VT/VF, which is caused by slowing of conduction via blockade of I(Na) (like Class Ic flecainide), may constitute a more important risk for terfenadine-induced cardiac death; (ii) although terfenadine is a potent hERG blocker, the risk for non-TdP-like VT/VF exceeds the risk for TdPs; and (iii) cardiac wavelength (λ) could serve as a biomarker to predict terfenadine-induced VT/VF. © 2012 Janssen Pharmaceutica NV. British Journal of Pharmacology © 2012 The British Pharmacological Society.
Muser, Daniele; Santangeli, Pasquale; Liang, Jackson J
Electrical storm (ES) is a medical emergency characterized by repetitive episodes of sustained ventricular arrhythmias (VAs) in a limited amount of time (at least 3 within a 24-h period) leading to repeated appropriate implantable cardioverter defibrillator therapies. The occurrence of ES represents a major turning point in the natural history of patients with structural heart disease being associated with poor short- and long-term survival particularly in those with compromised left ventricular ejection fraction (LVEF) that can develop hemodynamic decompensation and multi-organ failure. Management of ES is challenging with limited available evidence coming from small retrospective series and a substantial lack of randomized-controlled trials. In general, a multidisciplinary approach including medical therapies such as anti-arrhythmic drugs, sedation, as well as interventional approaches like catheter ablation, may be required. Accurate patient risk stratification at admission for ES is pivotal and should take into account hemodynamic tolerability of VAs as well as comorbidities like low LVEF, advanced NYHA class and chronic pulmonary disease. In high risk patients, prophylactic mechanical circulatory support with left ventricular assistance devices or extracorporeal membrane oxygenation should be considered as bridge to ablation and recovery. In the present manuscript we review the available strategies for management of ES and the evidence supporting them. PMID:28706587
Tao, Qian; Milles, Julien; van Huls van Taxis, Carine; Reiber, Johan H. C.; Zeppenfeld, Katja; van der Geest, Rob J.
Catheter ablation is an important option to treat ventricular tachycardias (VT). Scar-related VT is among the most difficult to treat, because myocardial scar, which is the underlying arrhythmogenic substrate, is patient-specific and often highly complex. The scar image from preprocedural late gadolinium enhancement magnetic resonance imaging (LGE- MRI) can provide high-resolution substrate information and, if integrated at the early stage of the procedure, can largely facilitate the procedure with image guidance. In clinical practice, however, early MRI integration is difficult because available integration tools rely on matching the MRI surface mesh and electroanatomical mapping (EAM) points, which is only possible after extensive EAM has been performed. In this paper, we propose to use a priori information on patient posture and a multi-sequence MRI integration framework to achieve accurate MRI integration that can be accomplished at an early stage of the procedure. From the MRI sequences, the left ventricular (LV) geometry, myocardial scar characteristics, and an anatomical landmark indicating the origin of the left main coronary artery are obtained preprocedurally using image processing techniques. Thereby the integration can be realized at the beginning of the procedure after acquiring a single mapping point. The integration method has been evaluated postprocedurally in terms of LV shape match and actual scar match. Compared to the iterative closest point (ICP) method that uses high-intensity mapping (225+/-49 points), our method using one mapping point reached a mean point-to-surface distance of 5.09+/-1.09 mm (vs. 3.85+/-0.60 mm, p<0.05), and scar correlation of -0.51+/-0.14 (vs. -0.50+/-0.14, p=NS).
Santangeli, Pasquale; Muser, Daniele; Zado, Erica S; Magnani, Silvia; Khetpal, Sumun; Hutchinson, Mathew D; Supple, Gregory; Frankel, David S; Garcia, Fermin C; Bala, Rupa; Riley, Michael P; Lin, David; Rame, J Eduardo; Schaller, Robert; Dixit, Sanjay; Marchlinski, Francis E; Callans, David J
The occurrence of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing radiofrequency catheter ablation of scar-related ventricular tachycardia (VT) has not been previously investigated. We identified univariate predictors of periprocedural AHD in 193 consecutive patients undergoing radiofrequency catheter ablation of scar-related VT. AHD was defined as persistent hypotension despite vasopressors and requiring mechanical support or procedure discontinuation. AHD occurred in 22 (11%) patients. Compared with the rest of the population, patients with AHD were older (68.5±10.7 versus 61.6±15.0 years; P=0.037); had a higher prevalence of diabetes mellitus (36% versus 18%; P=0.045), ischemic cardiomyopathy (86% versus 52%; P=0.002), chronic obstructive pulmonary disease (41% versus 13%; P=0.001), and VT storm (77% versus 43%; P=0.002); had more severe heart failure (New York Heart Association class III/IV: 55% versus 15%, P<0.001; left ventricular ejection fraction: 26±10% versus 36±16%, P=0.003); and more often received periprocedural general anesthesia (59% versus 29%; P=0.004). At 21±7 months follow-up, the mortality rate was higher in the AHD group compared with the rest of the population (50% versus 11%, log-rank P<0.001). AHD occurs in 11% of patients undergoing radiofrequency catheter ablation of scar-related VT and is associated with increased risk of mortality over follow-up. AHD may be predicted by clinical factors, including advanced age, ischemic cardiomyopathy, more severe heart failure status (New York Heart Association class III/IV, lower ejection fraction), associated comorbidities (diabetes mellitus and chronic obstructive pulmonary disease), presentation with VT storm, and use of general anesthesia. © 2014 American Heart Association, Inc.
Peichl, Petr; Wichterle, Dan; Čihák, Robert; Aldhoon, Bashar; Kautzner, Josef
Catheter ablation of ventricular tachycardia (VT) in patients with structural heart disease (SHD) is effective in prevention of arrhythmia recurrences. However, endocardial ablation may be challenging in the presence of organized left ventricular (LV) endocavitary thrombus. Our goal was to analyze the results of VT ablation in patients with identified old thrombus. We reviewed clinical and procedural data of 344 consecutive patients who underwent VT ablation for SHD. Old endocavitary thrombus was identified in four patients by preprocedural transthoracic echocardiography (TTE) and in four more patients by intracardiac echocardiography (ICE). All together, the case series of eight patients with detectable thrombus is reported. All patients (one woman, age: 67 ± 7 years) had postinfarction aneurysm (20 ± 8 years after the index myocardial infarction) and the thrombus was well organized without mobile structures. Arrhythmogenic substrate could not be obviously targeted beneath the base of thrombus; however, catheter ablation was successfully performed in the close vicinity. A total of 2.4 ± 1.2 procedures were necessary to abolish VT recurrences. Epicardial ablation was performed in three of eight (38%) patients as a second elective procedure. No procedural or periprocedural complications were observed. During the follow-up of 14 ± 15 months, two patients (25%) had sporadic VT recurrences. ICE seems to be more sensitive for the detection of LV thrombi compared to TTE and is helpful in real-time navigation of mapping/ablation catheter. Besides potential thromboembolic risk, large thrombus may prevent accessibility to the "critical" portion of arrhythmia circuit and epicardial ablation is required in selected cases. © 2016 Wiley Periodicals, Inc.
Bunch, T. Jared; Darby, Andy; May, Heidi T.; Ragosta, Michael; Lim, D. Scott; Taylor, Angela M.; DiMarco, John P.; Ailawadi, Gorav; Revenaugh, James R.; Weiss, J. Peter; Mahapatra, Srijoy
Aims Catheter ablation of ventricular tachycardia (VT) can be limited by haemodynamic instability. In these cases, substrate-based ablation is typically performed. An alternative is to perform activation and entrainment mapping during VT supported by a percutaneous left ventricular assist device (pVAD). We sought to compare the complication and success rates of pVAD-assisted VT ablation with scar-based techniques. Methods and results Thirteen consecutive patients with haemodynamically unstable VT underwent pVAD-assisted ablation (pVAD group) and were retrospectively compared with 18-matched patients undergoing a substrate-based VT ablation (non-pVAD group). There was no significant difference in age or ejection fraction between the groups although pVAD patients tended to have more shocks in the preceding months. Procedure times were longer for the pVAD group. The number of monomorphic VTs induced was greater in the pVAD group (3.2 vs. 1.6, P= 0.04); however, after ablation, there was no difference in inducibility between the pVAD and non-pVAD group (10 of 13 vs. 12 of 18; 77 vs. 67%, P = 0.69). There was no difference in acute complications including stroke or death. At 9 ± 3 months, 1-year freedom from implantable cardioverter-defibrillator (ICD) shocks/therapies for sustained VT were similar (P= 0.96). In multivariable analysis, the absence of atrial fibrillation (hazard ratio=0.15, P= 0.04) was associated with a lower incidence of ICD shocks. Conclusions In high-risk patients, pVAD-assisted VT ablation guided by activation and entrainment mapping is a feasible alternative to substrate mapping and allows outcomes comparable to substrate mapping. PMID:22080473
Liang, Jackson J; Betensky, Brian P; Muser, Daniele; Zado, Erica S; Anter, Elad; Desai, Nimesh D; Callans, David J; Deo, Rajat; Frankel, David S; Hutchinson, Mathew D; Lin, David; Riley, Michael P; Schaller, Robert D; Supple, Gregory E; Santangeli, Pasquale; Acker, Michael A; Bavaria, Joseph E; Szeto, Wilson Y; Vallabhajosyula, Prashanth; Marchlinski, Francis E; Dixit, Sanjay
Limited data exist on the long-term outcome of patients (pts) with non-ischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) refractory to conventional therapies undergoing surgical ablation (SA). We aimed to investigate the long-term survival and VT recurrence in NICM pts with VT refractory to radiofrequency catheter ablation (RFCA) who underwent SA. Consecutive pts with NICM and VT refractory to RFCA who underwent SA were included. VT substrate was characterized in the electrophysiology lab and targeted by RFCA. During SA, previous RFCA lesions/scars were identified and targeted with cryoablation (CA; 3 min/lesion; target -150 °C). Follow-up comprised office visits, ICD interrogations and the social security death index. Twenty consecutive patients with NICM who underwent SA (age 53 ± 16 years, 18 males, LVEF 41 ± 20%; dilated CM = 9, arrhythmogenic right ventricular CM = 3, hypertrophic CM = 2, valvular CM = 4, and mixed CM = 2) were studied. Percutaneous mapping/ablation in the electrophysiology lab was performed in 18 and 2 pts had primary SA. During surgery, 4.9 ± 4.0 CA lesions/pt were delivered to the endocardium (2) and epicardium (11) or both (7). VT-free survival was 72.5% at 1 year and over 43 ± 31 months (mos) (range 1-83mos), there was only one arrhythmia-related death. There was a significant reduction in ICD shocks in the 3-mos preceding SA vs. the entire follow-up period (6.6 ± 4.9 vs. 2.3 ± 4.3 shocks/pt, P = 0.001). In select pts with NICM and VT refractory to RFCA, SA guided by pre-operative electrophysiological mapping and ablation may be a therapeutic option.
Poussel, Mathias; Djaballah, Karim; Laroppe, Julien; Brembilla-Perrot, Béatrice; Marie, Pierre-Yves; Chenuel, Bruno
Objective: To emphasize the potentially harmful effects of high-intensity exercise on cardiac health and the fine line between physiologic and pathologic adaptation to chronic exercise in the elite athlete. This case also highlights the crucial need for regular evaluation of symptoms that suggest cardiac abnormality in athletes. Background: Sudden cardiac death (SCD) of young athletes is always a tragedy because they epitomize health. However, chronic, high-intensity exercise sometimes has harmful effects on cardiac health, and pathologic changes, such as myocardial fibrosis, have been observed in endurance athletes. In this case, a highly trained 30-year-old cyclist reported brief palpitations followed by presyncope feeling while exercising. Immediate investigations revealed nonsustained ventricular tachycardia originating from the left ventricle on a stress test associated with myocardial fibrosis of the left ventricle as shown with magnetic resonance imaging. Despite complete cessation of exercise, life-threatening arrhythmia and fibrosis persisted, leading to complete restriction from competition. Differential Diagnosis: Hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, myocarditis, postmyocarditis, use of drugs and toxic agents, doping, and systemic disease. Treatment: The arrhythmia could not be treated with catheter ablation procedure or drug suppression. Therefore, the athlete was instructed to withdraw completely from sport participation and to have a medical follow-up twice each year. Uniqueness: To our knowledge, no other report of left ventricle exercise-induced fibrosis associated with life-threatening arrhythmia in a living young elite athlete exists. Only postmortem evidence supports such myocardial pathologic adaptation to exercise. Conclusions: To prevent SCD in young athletes, careful attention must be paid to exercise-related symptoms that suggest a cardiac abnormality because they more often are linked to life
Fan, Roger; Cano, Oscar; Ho, Siew Yen; Bala, Rupa; Callans, David J; Dixit, Sanjay; Garcia, Fermin; Gerstenfeld, Edward P; Hutchinson, Mathew; Lin, David; Riley, Michael; Marchlinski, Francis E
Patients with nonischemic cardiomyopathy and ventricular tachycardia (VT) often have low-voltage areas in the lateral left ventricular (LV) epicardium that serve as the VT substrate. The course of the left phrenic nerve in this region may pose a challenge to successful and safe ablation. The purpose of this study was to delineate the left phrenic nerve course in patients with nonischemic cardiomyopathy and suspected epicardial VT and to characterize its relationship with the VT substrate. In 10 patients with nonischemic cardiomyopathy undergoing epicardial VT mapping and ablation, the course of the phrenic nerve was defined by pacing. The extent of epicardial LV low-voltage areas (<1.0 mV) was characterized by electroanatomic voltage mapping. Eight of 10 patients had low-voltage areas involving the lateral epicardial LV, and 7 of these 8 patients had sites of phrenic capture within these areas. Ablation was limited due to location of the phrenic nerve in two patients. In one of these patients, a balloon catheter was successfully used to mechanically protect the phrenic nerve during ablation. In the other five patients, adjacent ablation sites were targeted at which no phrenic capture with high-output pacing was demonstrated prior to ablation. In all patients undergoing ablation, the targeted VT became noninducible, and no patient demonstrated phrenic nerve injury. In most patients with nonischemic cardiomyopathy undergoing epicardial VT ablation, the phrenic nerve courses through a lateral LV low-voltage area in proximity to potential sites for ablation. Strategies to identify and protect the phrenic nerve are important.
Ahn, Jinhee; Kim, Dong-Hyeok; Roh, Seung-Young; Lee, Kwang No; Lee, Dae-In; Shim, Jaemin; Choi, Jong-Il
Background and Objectives Hemodynamically unstable idiopathic ventricular tachycardias (VTs) are a challenge for activation or entrainment mapping technique. Mechanical circulatory support is an option, but is not always readily available. In this study, we investigated the safety and efficacy of hemodynamic support using intravenous (IV) dopamine solely during radiofrequency catheter ablation (RFCA) of hemodynamically unstable VT. Subjects and Methods Seven out of 86 patients with hemodynamically unstable idiopathic VT underwent de novo RFCA using dopamine in our single center. They were included in the study and reviewed retrospectively to investigate the procedural characteristics and outcomes. Results All patients were male, and the mean age was 50.7±5.3 years. One patient had implantable cardioverter-defibrillator for the secondary prevention. No evidence of myocardial ischemia was found in all patients. During the procedure, the mean blood pressure during VT without dopamine was 52.3±4.1 mmHg and increased to 82.6±3.8 mmHg after administering dopamine (Δ28.8±3.2 mmHg; total average dopamine dosage was 1266.1±389.6 mcg/kg). In all patients, activation mapping was safely applied, and VTs were terminated during energy delivery. Non-inducibility of clinical VT was achieved in all cases. There was no evidence of deterioration due to hypoperfusion during the peri-procedural period. No recurrence of ventricular tachyarrhythmias was observed in any of the patients, during a median follow-up of 23.0±6.1 months. Conclusion Hemodynamic support using IV dopamine during RFCA of hemodynamically unstable idiopathic VT facilitated detailed mapping to guide successful ablation. PMID:28154593
Pokorney, Sean D.; Friedman, Daniel J.; Calkins, Hugh; Callans, David J.; Daoud, Emile G.; Della-Bella, Paolo; Jackson, Kevin P.; Shivkumar, Kalyanam; Saba, Samir; Sapp, John; Stevenson, William G.; Al-Khatib, Sana M.
Catheter ablation of ventricular tachycardia (VT) has evolved in recent years, especially in patients with ischemic heart disease. Data from prospective studies show that VT catheter ablation reduces the risk of recurrent VT; however, there is paucity of data on the effect of VT catheter ablation on mortality and patient centered outcomes such as quality of life. Performing randomized clinical trials of VT catheter ablation can be fraught with challenges, and as a result, several prior trials of VT catheter ablation had to be stopped prematurely. The main challenges are inability to blind the patient to therapy to obtain a traditional control group, high cross-over rates between the two arms of the study, patient refusal to participate in trials in which they have an equal chance of receiving a “pill” versus an invasive procedure, heterogeneity of mapping and ablation techniques as well as catheters and equipment, rapid evolution of technology that may make findings of any long trial less relevant to clinical practice, lack of consensus on what constitutes acute procedural and long-term success, and presentation of patients to electrophysiologists late in the course of their disease. In this paper, a panel of experts on VT catheter ablation and/or clinical trials of VT catheter ablation review challenges faced in conducting prior trials of VT catheter ablation and offer potential solutions for those challenges. It is hoped that the proposed solutions will enhance the feasibility of randomized clinical trials of VT catheter ablation. PMID:27050910
Reithmann, Christopher; Fiek, Michael; Hahnefeld, Anton; Ulbrich, Michael; Steinbeck, Gerhard
The purpose of the study was to evaluate the role of coronary venous mapping to identify epicardial ventricular tachycardia (VT) in patients with structural heart disease. Epicardial mapping of the electrophysiological substrate through the coronary vein branches using a 2.2F, 16-pole microelectrode catheter was performed in 33 consecutive patients undergoing VT ablation. Twenty-six patients had a history of myocardial infarction and seven had a non-ischaemic cardiomyopathy. Endocardial ablation was successful in 19 of the 33 patients (58%). Low-amplitude fractionated diastolic electrograms with an electrogram-QRS interval amounting to 30-70% of the VT cycle length were recorded during the VT in the coronary vein branches in eight patients (24%). Endocardial ablation failed in seven of the eight patients with diastolic electrograms in the coronary veins, suggesting an epicardial involvement of the VT re-entry circuit. Among the patients with a suspected epicardial VT origin, four patients underwent epicardial ablation using a pericardial access after unsuccessful endocardial ablation which eliminated mappable VTs in all. Recording of low-amplitude fractionated diastolic electrograms through the coronary veins facilitates the identification of VTs with an epicardial origin requiring mapping and ablation through a pericardial access.
Ringenberg, Jordan; Deo, Makarand; Filgueiras-Rama, David; Pizarro, Gonzalo; Ibañez, Borja; Peinado, Rafael; Merino, José L; Berenfeld, Omer; Devabhaktuni, Vijay
Myocardial fibrosis detected via delayed-enhanced magnetic resonance imaging (MRI) has been shown to be a strong indicator for ventricular tachycardia (VT) inducibility. However, little is known regarding how inducibility is affected by the details of the fibrosis extent, morphology, and border zone configuration. The objective of this article is to systematically study the arrhythmogenic effects of fibrosis geometry and extent, specifically on VT inducibility and maintenance. We present a set of methods for constructing patient-specific computational models of human ventricles using in vivo MRI data for patients suffering from hypertension, hypercholesterolemia, and chronic myocardial infarction. Additional synthesized models with morphologically varied extents of fibrosis and gray zone (GZ) distribution were derived to study the alterations in the arrhythmia induction and reentry patterns. Detailed electrophysiological simulations demonstrated that (1) VT morphology was highly dependent on the extent of fibrosis, which acts as a structural substrate, (2) reentry tended to be anchored to the fibrosis edges and showed transmural conduction of activations through narrow channels formed within fibrosis, and (3) increasing the extent of GZ within fibrosis tended to destabilize the structural reentry sites and aggravate the VT as compared to fibrotic regions of the same size and shape but with lower or no GZ. The approach and findings represent a significant step toward patient-specific cardiac modeling as a reliable tool for VT prediction and management of the patient. Sensitivities to approximation nuances in the modeling of structural pathology by image-based reconstruction techniques are also implicated. PMID:25368538
Proietti, Riccardo; Roux, Jean-Francois; Verma, Atul; Alturki, Ahmed; Bernier, Martin L; Essebag, Vidal
The ablation strategy for ventricular tachycardia (VT) rapidly evolved from an entrainment mapping approach for identification of the critical isthmus of the re-entrant circuit during monomorphic VT, toward a substrate-based approach aiming to ablate surrogate markers of the circuit during sinus rhythm in hemodynamically nontolerated and polymorphic VT. The latter approach implies an assumption that the circuits responsible for the arrhythmia are anatomical or fixed, and present during sinus rhythm. Accordingly, the lines of block delimiting the channels of the circuits are often considered fixed, although there is evidence that they are functional or more frequently a combination of fixed and functional. The electroanatomical substrate-based approach to VT ablation performed during sinus rhythm is increasingly adopted in clinical practice and often described as scar homogenization, scar dechanneling, or core isolation. However, whether the surrogate markers of the VT circuit during sinus rhythm match the circuit during arrhythmias remains to be fully demonstrated. The myocardial scar is a heterogeneous electrophysiological milieu with complex arrhythmogenic mechanisms that potentially coexist simultaneously. Moreover, the scar consists of different areas of diverse refractoriness and conduction. It can be misleading to limit the arrhythmogenic perspective of the myocardial scar to fixed or anatomical barriers held responsible for the re-entry circuit. Greater understanding of the role of functional lines of block in VT and the validity of the surrogate targets being ablated is necessary to further improve the technique and outcome of VT ablation. ©2016 Wiley Periodicals, Inc.
Salas-Boni, Rebeca; Bai, Yong; Harris, Patricia Rae Eileen; Drew, Barbara J; Hu, Xiao
Over the past few years, reducing the number of false positive cardiac monitor alarms (FA) in the intensive care unit (ICU) has become an issue of the utmost importance. In our work, we developed a robust methodology that, without the need for additional non-ECG waveforms, suppresses false positive ventricular tachycardia (VT) alarms without resulting in false negative alarms. Our approach is based on features extracted from the ECG signal 20 seconds prior to a triggered alarm. We applied a multi resolution wavelet transform to the ECG data 20seconds prior to the alarm trigger, extracted features from appropriately chosen scales and combined them across all available leads. These representations are presented to a L1-regularized logistic regression classifier. Results are shown in two datasets of physiological waveforms with manually assessed cardiac monitor alarms: the MIMIC II dataset, where we achieved a false alarm (FA) suppression of 21% with zero true alarm (TA) suppression; and a dataset compiled by UCSF and General Electric, where a 36% FA suppression was achieved with a zero TA suppression. The methodology described in this work could be implemented to reduce the number of false monitor alarms in other arrhythmias. Copyright © 2014 Elsevier Inc. All rights reserved.
Pokorney, Sean D; Friedman, Daniel J; Calkins, Hugh; Callans, David J; Daoud, Emile G; Della-Bella, Paolo; Jackson, Kevin P; Shivkumar, Kalyanam; Saba, Samir; Sapp, John; Stevenson, William G; Al-Khatib, Sana M
Catheter ablation of ventricular tachycardia (VT) has evolved in recent years, especially in patients with ischemic heart disease. Data from prospective studies show that VT catheter ablation reduces the risk of recurrent VT; however, there is a paucity of data on the effect of VT catheter ablation on mortality and patient-centered outcomes such as quality of life. Performing randomized clinical trials of VT catheter ablation can be fraught with challenges, and, as a result, several prior trials of VT catheter ablation had to be stopped prematurely. The main challenges are inability to blind the patient to therapy to obtain a traditional control group, high crossover rates between the 2 arms of the study, patient refusal to participate in trials in which they have an equal chance of receiving a "pill" vs an invasive procedure, heterogeneity of mapping and ablation techniques as well as catheters and equipment, rapid evolution of technology that may make findings of any long trial less relevant to clinical practice, lack of consensus on what constitutes acute procedural and long-term success, and presentation of patients to electrophysiologists late in the course of their disease. In this article, a panel of experts on VT catheter ablation and/or clinical trials of VT catheter ablation review challenges faced in conducting prior trials of VT catheter ablation and offer potential solutions for those challenges. It is hoped that the proposed solutions will enhance the feasibility of randomized clinical trials of VT catheter ablation.
Constitutive Intracellular Na+ Excess in Purkinje Cells Promotes Arrhythmogenesis at Lower Levels of Stress Than Ventricular Myocytes From Mice With Catecholaminergic Polymorphic Ventricular Tachycardia.
Willis, B Cicero; Pandit, Sandeep V; Ponce-Balbuena, Daniela; Zarzoso, Manuel; Guerrero-Serna, Guadalupe; Limbu, Bijay; Deo, Makarand; Camors, Emmanuel; Ramirez, Rafael J; Mironov, Sergey; Herron, Todd J; Valdivia, Héctor H; Jalife, José
In catecholaminergic polymorphic ventricular tachycardia (CPVT), cardiac Purkinje cells (PCs) appear more susceptible to Ca(2+) dysfunction than ventricular myocytes (VMs). The underlying mechanisms remain unknown. Using a CPVT mouse (RyR2(R4496C+/Cx40eGFP)), we tested whether PC intracellular Ca(2+) ([Ca(2+)]i) dysregulation results from a constitutive [Na(+)]i surplus relative to VMs. Simultaneous optical mapping of voltage and [Ca(2+)]i in CPVT hearts showed that spontaneous Ca(2+) release preceded pacing-induced triggered activity at subendocardial PCs. On simultaneous current-clamp and Ca(2+) imaging, early and delayed afterdepolarizations trailed spontaneous Ca(2+) release and were more frequent in CPVT PCs than CPVT VMs. As a result of increased activity of mutant ryanodine receptor type 2 channels, sarcoplasmic reticulum Ca(2+) load, measured by caffeine-induced Ca(2+) transients, was lower in CPVT VMs and PCs than respective controls, and sarcoplasmic reticulum fractional release was greater in both CPVT PCs and VMs than respective controls. [Na(+)]i was higher in both control and CPVT PCs than VMs, whereas the density of the Na(+)/Ca(2+) exchanger current was not different between PCs and VMs. Computer simulations using a PC model predicted that the elevated [Na(+)]i of PCs promoted delayed afterdepolarizations, which were always preceded by spontaneous Ca(2+) release events from hyperactive ryanodine receptor type 2 channels. Increasing [Na(+)]i monotonically increased delayed afterdepolarization frequency. Confocal imaging experiments showed that postpacing Ca(2+) spark frequency was highest in intact CPVT PCs, but such differences were reversed on saponin-induced membrane permeabilization, indicating that differences in [Na(+)]i played a central role. In CPVT mice, the constitutive [Na(+)]i excess of PCs promotes triggered activity and arrhythmogenesis at lower levels of stress than VMs. © 2016 The Authors.
Constitutive Intracellular Na+ Excess in Purkinje Cells Promotes Arrhythmogenesis at Lower Levels of Stress Than Ventricular Myocytes From Mice With Catecholaminergic Polymorphic Ventricular Tachycardia
Willis, B. Cicero; Pandit, Sandeep V.; Ponce-Balbuena, Daniela; Zarzoso, Manuel; Guerrero-Serna, Guadalupe; Limbu, Bijay; Deo, Makarand; Camors, Emmanuel; Ramirez, Rafael J.; Mironov, Sergey; Herron, Todd J.; Valdivia, Héctor H.
Background— In catecholaminergic polymorphic ventricular tachycardia (CPVT), cardiac Purkinje cells (PCs) appear more susceptible to Ca2+ dysfunction than ventricular myocytes (VMs). The underlying mechanisms remain unknown. Using a CPVT mouse (RyR2R4496C+/Cx40eGFP), we tested whether PC intracellular Ca2+ ([Ca2+]i) dysregulation results from a constitutive [Na+]i surplus relative to VMs. Methods and Results— Simultaneous optical mapping of voltage and [Ca2+]i in CPVT hearts showed that spontaneous Ca2+ release preceded pacing-induced triggered activity at subendocardial PCs. On simultaneous current-clamp and Ca2+ imaging, early and delayed afterdepolarizations trailed spontaneous Ca2+ release and were more frequent in CPVT PCs than CPVT VMs. As a result of increased activity of mutant ryanodine receptor type 2 channels, sarcoplasmic reticulum Ca2+ load, measured by caffeine-induced Ca2+ transients, was lower in CPVT VMs and PCs than respective controls, and sarcoplasmic reticulum fractional release was greater in both CPVT PCs and VMs than respective controls. [Na+]i was higher in both control and CPVT PCs than VMs, whereas the density of the Na+/Ca2+ exchanger current was not different between PCs and VMs. Computer simulations using a PC model predicted that the elevated [Na+]i of PCs promoted delayed afterdepolarizations, which were always preceded by spontaneous Ca2+ release events from hyperactive ryanodine receptor type 2 channels. Increasing [Na+]i monotonically increased delayed afterdepolarization frequency. Confocal imaging experiments showed that postpacing Ca2+ spark frequency was highest in intact CPVT PCs, but such differences were reversed on saponin-induced membrane permeabilization, indicating that differences in [Na+]i played a central role. Conclusions— In CPVT mice, the constitutive [Na+]i excess of PCs promotes triggered activity and arrhythmogenesis at lower levels of stress than VMs. PMID:27169737
Clemens, Marcell; Peichl, Petr; Wichterle, Dan; Pavlů, Luděk; Čihák, Robert; Aldhoon, Bashar; Kautzner, Josef
Patients with coronary artery disease (CAD), relatively preserved left ventricular ejection fraction (LVEF), and hemodynamically tolerated ventricular tachycardia (VT) may benefit from catheter ablation as the first-line treatment. Our aim was to analyze the long-term results of VT ablation in this population. Thirty-one patients (1 woman, mean age 67 ± 10 years) with CAD, tolerated VT, and LVEF ≥40% underwent catheter ablation as the first-line treatment of the arrhythmia. Catheter ablation was performed in order to abolish all inducible VTs. An ICD was implanted if sustained VT of any morphology remained inducible after the procedure. The mean LVEF was 48 ± 6% and the mean VT cycle length reached 348 ± 70 milliseconds in the study cohort. Clinical and all inducible VTs were abolished in 90% (28/31) and 58% (18/31) of the patients, respectively. An ICD was subsequently implanted in 42% of cases. Over a mean follow-up of 3.8 ± 2.9 years, 42% (13/31) patients died. Survival of the patients with or without the ICD was not significantly different (P = 0.47). VT recurrence was observed in 11% (2/18) of patients who had complete elimination of all inducible VTs. No sudden death occurred in patients without the ICD. Catheter ablation of VT as the first-line treatment in patients with CAD and relatively preserved LVEF is a viable strategy. It may prevent implantation of the ICD in a considerable proportion of patients. Abolition of all inducible VTs confers low VT recurrence rate over a long-term follow-up. © 2015 Wiley Periodicals, Inc.
Xue, Yumei; Fang, Xianhong; Huang, Jun; Liu, Yang; Deng, Hai; Liang, Yuanhong; Liao, Zili; Liu, Fangzhou; Lin, Weidong; Zhan, Xianzhang; Wu, Shulin
Aims To summarize our experience of radiofrequency catheter ablation (RFCA) for recurrent drug-refractory ventricular tachycardias (VTs) due to arrhythmogenic right ventricular cardiomyopathy (ARVC) in our center over the past 11 years and its related factors. Methods and Results We reviewed 48 adults (mean age 39.9 ± 12.9 years, range: 14 to 65) who met the present ARVC diagnostic criteria and accepted RFCA for VTs from December 2004 to April 2016. The patients received a total of 70 procedures using two ablation approaches, the endocardial approach in 52 RFCAs, and the combined epicardial and endocardial approach (the combined approach) in 18 RFCAs. Kaplan-Meier survival analysis showed that the combined approach achieved better acute procedural success (p = 0.003) and better long-term outcomes (p = 0.028) than the endocardial approach. Patients who obtained acute procedural success with non-inducibility had better long-term outcomes (p < 0.001). COX regression of multivariate analysis showed that procedural success was the only factor that benefited long-term outcome, irrespective of the endocardial or the combined approach (p = 0.001). The rate of sudden cardiac death (SCD) in patients without procedural success was significantly higher than that in patients with procedural success (p = 0.005). All patients without implantable cardioverter defibrillator (ICD) implantation who had successful final RFCA survived. Conclusions The combined approach resulted in better procedural success and long-term VT-free survival compared with the endocardial approach in ARVC patients with recurrent VTs. Acute procedural success with non-inducibility was strongly related to better long-term VT-free survival and reduced SCD, irrespective of whether this was achieved by the endocardial approach or the combined approach. PMID:28122031
Akerström, Finn; Pachón, Marta; García-Fernández, Francisco Javier; Salvador-Montañés, Óscar; Jensen-Urstad, Mats; Puchol, Alberto; Peinado, Rafael; Salgado, Ricardo; Insulander, Per; Rodríguez-Padial, Luis; Arias, Miguel A
Ventricular overdrive pacing (VOP) produces reset during the transition zone (TZ) of QRS fusion in orthodromic reentrant tachycardia (ORT) and after the TZ in atrioventricular nodal reentrant tachycardia (AVNRT), and this represents a simple diagnostic maneuver to differentiate the two tachycardia mechanisms. The purpose of this study was to determine whether the number of beats with reset in the TZ predicts accessory pathway (AP) location in ORT. We retrospectively reviewed 57 patients with ORT (21 left-sided AP, 20 septal AP, and 16 right-sided AP) and 20 patients with AVNRT (19 typical AVNRT and one atypical AVNRT) who underwent VOP from the right ventricular apex. We analyzed the number of beats with reset during or after the TZ, demonstrated by fixed ventricular stimulus-atrial (SA) interval during VOP. The overall mean tachycardia cycle length [CL] minus VOP CL was 22.6 ± 7.5 ms with no statistical difference between the groups (P = 0.480). The mean number of beats in the TZ with fixed SA interval was 2.5 ± 1.4 for the whole ORT group, 1.1 ± 0.4 for left-sided AP (range 1-2), 2.8 ± 0.9 for septal AP (range 1-5), and 4.0 ± 0.9 for right-sided AP (range 3-6) (P < 0.001). Using a cutoff >2 beats distinguished right- versus left-sided AP in all cases. Assessing the number of beats in the TZ with fixed SA interval during VOP helps to determine AP location in ORT and adds valuable information to an established simple diagnostic pacing maneuver, especially when a two-catheter simplified approach is employed. ©2015 Wiley Periodicals, Inc.
Brouwer, Charlotte; Hazekamp, Mark G
Advances in surgical repair techniques for various types of congenital heart disease have improved survival into adulthood over the past decades, thus exposing these patients to a high risk of atrial and ventricular arrhythmias later in life. These arrhythmias arise from complex arrhythmogenic substrates. Substrate formation may depend on both pathological myocardial remodelling and variable anatomical boundaries, determined by the type and timing of prior corrective surgery. Accordingly, arrhythmogenic substrates after repair have changed as a result of evolving surgical techniques. Radiofrequency catheter ablation offers an important therapeutic option but remains challenging due to the variable anatomy, surgically created obstacles and the complex arrhythmogenic substrates. Recent technical developments including electroanatomical mapping and image integration for delineating the anatomy facilitate complex catheter ablation procedures. The purpose of this review is to provide an update on the changing anatomical arrhythmogenic substrates and their potential impact on catheter ablation in patients with repaired congenital heart disease and tachyarrhythmias. PMID:27617095
Aizawa, Yoshiyasu; Takatsuki, Seiji; Nishiyama, Takahiko; Kimura, Takehiro; Kohsaka, Shun; Kaneko, Yoshiaki; Inden, Yasuya; Takahashi, Naohiko; Nagase, Satoshi; Aizawa, Yoshifusa; Fukuda, Keichi
To know the underlying mechanisms of J waves, the response to atrial pacing was studied in patients with idiopathic ventricular fibrillation (IVF) and patients with non-IVF. In 8 patients with IVF, the J-wave amplitude was measured before, during, and after atrial pacing. All patients had episodes of ventricular fibrillation without structural heart disease. The responses of J waves were compared with those of the 17 non-IVF control subjects who revealed J waves but no history of cardiac arrest and underwent electrophysiological study. The IVF patients were younger than the non-IVF patients (28±10 versus 52±14 years, respectively; P=0.002) and had larger J waves with more extensive distribution. J waves decreased from 0.35±0.26 to 0.22±0.23 mV (P=0.025) when the RR intervals were shortened from 782±88 to 573±162 ms (P=0.001). A decrease (≥0.05 mV) in the J-wave amplitude was observed in 6 of the 8 patients. In addition, 1 patient showed a distinct reduction of J waves in the unipolar epicardial leads. In contrast, J waves were augmented in the 17 non-IVF subjects from 0.27±0.09 to 0.38±0.10 mV (P<0.001): augmented in 9 and unchanged in the 8 subjects. The different response patterns of J waves to rapid pacing suggest different mechanisms: early repolarization in IVF patients and conduction delay in non-IVF patients. The response to atrial pacing was different between the IVF and non-IVF patients, which suggests the presence of different mechanisms for the genesis of J waves. © 2017 American Heart Association, Inc.
Can ventricular tachycardia non-inducibility after ablation predict reduced ventricular tachycardia recurrence and mortality in patients with non-ischemic cardiomyopathy? A meta-analysis of twenty-four observational studies.
Hu, Jinzhu; Zeng, Shan; Zhou, Qiongqiong; Zhu, Wengen; Xu, Zhenyan; Yu, Jianhua; Hong, Kui
At present, the role of ventricular tachycardia (VT) non-inducibility after ablation in patients with non-ischemic cardiomyopathy (NICM) remains controversial. We conducted a meta-analysis of the published literature to assess whether VT non-inducibility after ablation could predict reduced VT recurrence and mortality in patients with NICM. PubMed, ScienceDirect, and the Cochrane library were searched for studies evaluating the effects of VT non-inducibility after catheter ablation on the long-term outcome in NICM patients with sustained VT. Results were analyzed using a fixed-effect model, and the data were pooled using RevMan 5.3 software. Twenty-four observational studies were identified (736 participants, mean follow-up time: 22months). NICM patients with VT inducibility after ablation had a higher risk of VT recurrence (odds ratio [OR]=5.83, 95% confidence interval [CI] 4.07-8.37; P<0.00001) and all-cause mortality (OR=3.55, 95% CI 1.62-7.78; P=0.002) compared with VT non-inducibility. Similarly in the subgroup analysis, patients with VT inducibility showed a higher risk of VT recurrence from non-ischemic dilated cardiomyopathy (OR=3.92, 95% CI 2.36-6.50; P<0.00001) and arrhythmogenic right ventricular dysplasia/cardiomyopathy (OR=5.37, 95% CI 2.20-13.10; P=0.0002). Additionally, meta-analysis also showed that combined endo-epicardial ablation significantly reduced the risk of VT recurrence compared with endocardial-only ablation (OR=2.02, 95% CI 1.19-3.44; P=0.009; mean follow-up time: 22months). Recent evidence has shown that VT non-inducibility after ablation is a predictor for reduced VT recurrence and mortality compared with VT inducibility in NICM patients with sustained VT. In addition, endocardial plus adjuvant epicardial ablation provides better long-term arrhythmia-free survival than endocardial ablation alone. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Morishima, Itsuro; Nogami, Akihiko; Tsuboi, Hideyuki; Sone, Takahito
Uncommon association of left anterior fascicular ventricular tachycardia (VT) with a healed myocardial infarction (MI) is described. A 55-year-old man with a history of anteroseptal MI had verapamil-sensitive VT. The VT exhibited a right bundle branch block configuration and right-axis deviation. The VT exit was located at the left ventricular anterolateral wall. At the mid-anterior left ventricular septum, delayed Purkinje potentials were seen during sinus rhythm, and the optimal pace map was obtained with pace delay. During the VT, diastolic and systolic Purkinje potentials were simultaneously recorded at the same site. Ablation targeting the delayed potentials during sinus rhythm prolonged the time between QRS onset and the delayed potentials, and the VT no longer became inducible when the delayed potentials were completely eliminated. Left anterior fascicular VT develops in post-MI patients; ischemia-injured His-Purkinje system may be involved in the mechanism of the VT.
Catheter Ablation of Ventricular Tachycardia/Fibrillation in a Patient with Right Ventricular Amyloidosis with Initial Manifestations Mimicking Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy
Chung, Fa-Po; Lin, Yenn-Jiang; Kuo, Ling
Differentiating arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) from other cardiomyopathies is clinically important but challenging. Although the modified Task Force Criteria can facilitate diagnosis of ARVD/C according to clinical manifestations, histopathological examination plays a pivotal role in excluding other diseases that can mimic ARVD/C. Here, we report a patient with amyloidosis that initially presented similarly to ARVD/C. The diagnosis was confirmed by endomyocardial biopsy, and catheter ablation eliminated the ventricular tachyarrhythmias through an epicardial approach. PMID:28382086
Bernus, O.; Van Eyck, B.; Verschelde, H.; Panfilov, A. V.
We study the effect of blocking the L-type Ca2+-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 Ca2+-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 × 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.
Tung, Roderick; Vaseghi, Marmar; Frankel, David S.; Vergara, Pasquale; DiBiase, Luigi; Nagashima, Koichi; Yu, Ricky; Vangala, Sitaram; Tseng, Chi-Hong; Choi, Eue-Keun; Khurshid, Shaan; Patel, Mehul; Mathuria, Nilesh; Nakahara, Shiro; Tzou, Wendy S.; Sauer, William H.; Vakil, Kairav; Tedrow, Usha; Burkhardt, David; Tholakanahalli, Venkat; Saliaris, Anastasios; Dickfeld, Timm; Weiss, J. Peter; Bunch, T. Jared; Reddy, Madhu; Kanmanthareddy, Arun; Callans, David; Lakkireddy, Dhanunjaya; Natale, Andrea; Marchlinski, Francis; Stevenson, William G.; Della Bella, Paolo; Shivkumar, Kalyanam
Background The impact of catheter ablation of ventricular tachycardia (VT) on all-cause mortality remains unknown. Objective To examine the association between VT recurrence after ablation and survival in patients with scar-related VT. Methods Analysis of 2,061 patients with structural heart disease referred for catheter ablation of scar-related VT from 12 international centers was performed. Data on clinical and procedural variables, VT recurrence, and mortality were analyzed. Kaplan-Meier analysis was used to estimate freedom from recurrent VT, transplant, and death. Cox proportional hazards frailty models were used to analyze the effect of risk factors on VT recurrence and mortality. Results One-year freedom from VT recurrence was 70% (72% in ischemic and 68% in non-ischemic cardiomyopathy). 57 (3%) patients underwent cardiac transplantation and 216 (10%) died during follow-up. At one year, the estimated rate of transplant and/or mortality was 15% (same for ischemic and non-ischemic cardiomyopathy). Transplant-free survival was significantly higher in patients without VT recurrence compared to those with recurrence (90% vs. 71%, p<0.001). In multivariable analysis, recurrence of VT after ablation showed the highest risk for transplant and/or mortality (HR 6.9 (5.3-9.0); p<0.001). In patients with EF<30% and across all NYHA classes, improved transplant-free survival was seen in those without VT recurrence. Conclusions Catheter ablation of VT in patients with structural heart disease results in 70% freedom from VT recurrence, with an overall transplant and/or mortality rate of 15% at 1 year. Freedom from VT recurrence is associated with improved transplant-free survival, independent of heart failure severity. PMID:26031376
Nagashima, Koichi; Choi, Eue-Keun; Tedrow, Usha B; Koplan, Bruce A; Michaud, Gregory F; John, Roy M; Epstein, Laurence M; Tokuda, Michifumi; Inada, Keiichi; Kumar, Saurabh; Lin, Kaity Y; Barbhaiya, Chirag R; Chinitz, Jason S; Enriquez, Alan D; Helmbold, Alan F; Stevenson, William G
Catheter ablation for ventricular tachycardia (VT) from structural heart disease has a significant risk of recurrence, but the optimal duration for in-hospital monitoring is not defined. This study assesses the timing, correlates, and prognostic significance of early VT recurrence after ablation. Of 370 patients (313 men; aged 63.0±13.2 years) who underwent a first radiofrequency ablation for sustained monomorphic VT associated with structural heart disease from 2008 to 2012, sustained VT recurred in 81 patients (22%) within 7 days. In multivariable analysis, early recurrence was associated with New York Heart Association classification ≥III (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.03-3.48; P=0.04), dilated cardiomyopathy (OR 1.93, 95% CI 1.03-3.57; P=0.04), prevalence of VT storm before the procedure (OR 2.62, 95% CI 1.48-4.65; P=0.001), a greater number of induced VTs (OR 1.24, 95% CI 1.07-1.45; P=0.006), and acute failure or no final induction test (OR 1.88, 95% CI 1.03-3.40; P=0.04). During a median of 2.5 (1.2, 4.0) years of follow-up, early VT recurrence was an independent correlates of mortality (hazard ratio 2.59, 95% CI 1.52-4.34; P=0.0005). Patients who have early recurrences of VT after ablation are a high risk group who may be identifiable from their clinical profile. Further study is warranted to define the optimal treatment strategies for this patient group. © 2014 American Heart Association, Inc.
Yu, Ricky; Ma, Sootkeng; Tung, Roderick; Stevens, Steven; Macias, Carlos; Bradfield, Jason; Buch, Eric; Vaseghi, Marmar; Fujimura, Osama; Gornbein, Jeffrey; Mandapati, Ravi; Shivkumar, Kalyanam; Boyle, Noel G
Ablation has become an important option for treatment of ventricular tachycardia (VT). The influence of procedure duration on outcomes remains unexamined. The purpose of this study was to determine the influence of procedure duration on outcomes and complications over an 8-year period Patients referred for scar-mediated VT ablation from 2004 to 2011 were retrospectively analyzed. Procedure duration was defined as the time from the insertion of catheters through the femoral vein to the time of their withdrawal. Procedure duration was analyzed in relationship with baseline and intraoperative covariates, acute procedural outcomes, complications, and 6-month clinical outcomes. One hundred forty-eight patients underwent VT ablation with mean procedure duration of 5.7 ± 1.8 hours. VT recurrence and survival at 6 months were 46% and 82%, respectively, and were not associated with procedure duration. Hospital mortality increased with intraoperative intraaortic balloon pump insertion (adjusted odds ratio [OR] 13.7, 95% confidence interval [CI] 2.35-79.94, P = .004) and was improved with successful ablation of the clinical VT as a procedural end-point (adjusted OR 0.13, 95% Cl 0.03-0.54, P = .005). The association between procedure duration and hospital mortality remained after adjusting for significant baseline variables (adjusted OR 1.75, 95% CI 1.14-2.68, P = .0098) and intraoperative variables (adjusted OR 1.6, 95% CI 1.12-2.29, P = .0104). Hospital mortality was significantly increased by unsuccessful clinical VT ablation as a procedural end-point and intraoperative intraaortic balloon pump insertion. However, after adjusting for significant baseline and intraoperative covariates, procedure duration still was associated with increased hospital mortality. Procedure duration had no impact on VT recurrence and survival at 6 months. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Mahapatra, Srijoy; LaPar, Damien J.; Bhamidipati, Castigliano M.; McDaniel, George; Kamath, Sandeep; Bunch, T. Jared; Ailawadi, Gorav
Introduction We sought to determine the incidence, predictors, and consequences of new-onset atrial fibrillation (AF) following epicardial ventricular tachycardia (VT) ablation. Methods and results A total of 41 patients with no prior history of AF underwent epicardial VT ablation via a percutaneous subxiphoid approach. All patients were monitored continuously for 3 days following ablation and then via implantable cardiac defibrillator (ICD) or Holter monitoring. Mean age was 70.0 ± 11.3 years and mean ejection fraction was 30.3 ± 16.6%. In seven (17%) patients, the right ventricle (RV) was punctured during access with subsequent needle withdrawal without requiring surgical repair. Thirty patients (73%) were treated with amiodarone following ablation. Post-ablation, eight (19.5%) patients had documented new-onset AF within 7 days. All AF patients had clinical symptoms of pericarditis. One patient with AF was maintained on amiodarone post-procedure. Complications of AF included three patients who received inappropriate ICD shocks and one patient who developed a large, left atrial appendage clot. Acutely, all patients responded to short-term medical therapy or electrical cardioversion. At 18.0 ± 9.0 months of follow-up, no patient had recurrence of AF, and all were off antiarrhythmic drugs. One patient had typical atrial flutter requiring catheter ablation. Risk factors for AF included lack of amiodarone immediately after ablation (12.5 vs. 87.9%, P< 0.001), RV puncture (50.0 vs. 9.1%, P= 0.02), and epicardial ablation time >10 min (62.5 vs. 3.0%, P< 0.001). Conclusions Atrial fibrillation after epicardial ablation is common and can lead to ICD shocks and atrial thrombus formation. Short-term antiarrhythmic drug therapy and ICD reprogramming should be considered after epicardial VT ablation. PMID:21296778
Tsiachris, Dimitris; Silberbauer, John; Maccabelli, Giuseppe; Oloriz, Teresa; Baratto, Francesca; Mizuno, Hiroya; Bisceglia, Caterina; Vergara, Pasquale; Marzi, Alessandra; Sora, Nicoleta; Guarracini, Fabrizio; Radinovic, Andrea; Cireddu, Manuela; Sala, Simone; Gulletta, Simone; Paglino, Gabriele; Mazzone, Patrizio; Trevisi, Nicola; Della Bella, Paolo
Catheter ablation is an important therapeutic option in postmyocardial infarction patients with ventricular tachycardia (VT). We analyzed the endo-epicardial electroanatomical mapping (EAM) voltage and morphology characteristics, their association with clinical data and their prognostic value in a large cohort of postmyocardial infarction patients. We performed total and segmental analysis of voltage (bipolar dense scar [DS] and low voltage areas, unipolar low voltage and penumbra areas) and morphology characteristics (presence of abnormal late potentials [LPs] and early potentials [EPs]) in 100 postmyocardial infarction patients undergoing electroanatomical mapping-based VT ablation (26 endo-epicardial procedures) from 2010-2012. All patients had unipolar low voltage areas, whereas 18% had no identifiable endocardial bipolar DS areas. Endocardial bipolar DS area >22.5 cm(2) best predicted scar transmurality. Endo-epicardial LPs were recorded in 2/3 patients, more frequently in nonseptal myocardial segments and were abolished in 51%. Endocardial bipolar DS area >7 cm(2) and endocardial bipolar scar density >0.35 predicted epicardial LPs. Isolated LPs are located mainly epicardially and EPs endocardially. As a primary strategy, LPs and VT-mapping ablation occurred in 48%, only VT-mapping ablation in 27%, only LPs ablation in 17%, and EPs ablation in 6%. Endocardial LP abolition was associated with reduced VT recurrence and increased unipolar penumbra area predicted cardiac death. Endocardial scar extension and density predict scar transmurality and endo-epicardial presence of LPs, although DS is not always identified in postmyocardial infarction patients. LPs, most frequently located in nonseptal myocardial segments, were abolished in 51% resulting in improved outcome. © 2015 American Heart Association, Inc.
Akca, Ferdi; Önsesveren, Ibrahim; Jordaens, Luc; Szili-Torok, Tamas
Remote magnetic navigation (RMN) is considered to be a solution for mapping and ablation of several arrhythmias. In this systematic review we aimed to assess the safety and efficacy of RMN in ablation of ventricular tachycardia (VT). The National Library of Medicine's PubMed database was searched for articles containing any of a predetermined set of search terms that were published prior to November 1, 2011. Quality of evidence was rated using the GRADE system. The database search resulted in 11 relevant articles evaluating the usefulness of RMN. Three groups of VTs were studied: VT in patients with ischemic cardiomyopathy (ICMP), non-ischemic cardiomyopathy (NICMP) and structurally normal hearts (SNH). The use of RMN in patients with ICMP has been associated with success rates ranging from 71 to 80%. RMN has been shown to be a feasible and effective method for ablation of VT in NICMP and SNH patients. Success rates between 50% and 100% have been reported in NICMP populations. Rates ranging from 86% to 100% have been reported for SNH patients. The lowest rates of arrhythmia recurrence are reported for SNH patients (0-17%). In ICMP and NICMP, recurrence rates of 0-30% and 14-50%, respectively, have been reported. One patient experienced total heart block, and one patient experienced a thromboembolic event after RMN catheter ablation procedures. RMN has been shown to be an effective and safe method for ablation of VT in various patient populations with low recurrence and complication rates. However, more comparative and randomized studies are necessary, and therefore the true value of RMN for VT ablation remains still unknown.
Vega, Amanda L.; Tester, David J.; Ackerman, Michael J.; Makielski, Jonathan C.
Background KCNJ2 encodes Kir2.1, a pore-forming subunit of the cardiac inward rectifier current, IK1. KCNJ2 mutations are associated with Andersen-Tawil syndrome (ATS) and also Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). The aim of this study was to characterize the biophysical and cellular phenotype of a KCNJ2 missense mutation, V227F, found in a patient with CPVT. Methods and Results Kir2.1-wild type (WT) and V227F channels were expressed individually and together in Cos-1 cells to measure IK1 by voltage clamp. Unlike typical ATS-associated KCNJ2 mutations which show dominant negative loss of function, Kir2.1WT+V227F co-expression yielded IK1 indistinguishable from Kir2.1-WT under basal conditions. To simulate catecholamine activity, a PKA-stimulating cocktail comprised of forskolin and 3-isobutyl-1-methylxanthine (IBMX) was used to increase PKA activity. This PKA-simulated catecholaminergic stimulation caused marked reduction of outward IK1 compared to Kir2.1-WT. PKA-induced reduction in IK1 was eliminated by mutating the phosphorylation site at serine 425 (S425N). Conclusions Heteromeric Kir2.1-V227F and WT channels showed an unusual latent loss of function biophysical phenotype that depended upon PKA-dependent Kir2.1 phosphorylation. This biophysical phenotype, distinct from typical ATS mutations, suggests a specific mechanism for PKA dependent IK1 dysfunction for this KCNJ2 mutation which correlates with adrenergic conditions underlying the clinical arrhythmia. PMID:19843922
Yamashita, Seigo; Cochet, Hubert; Sacher, Frédéric; Mahida, Saagar; Berte, Benjamin; Hooks, Darren; Sellal, Jean-Marc; Al Jefairi, Nora; Frontera, Antonio; Komatsu, Yuki; Lim, Han S; Amraoui, Sana; Denis, Arnaud; Derval, Nicolas; Sermesant, Maxime; Laurent, François; Hocini, Mélèze; Haïssaguerre, Michel; Montaudon, Michel; Jaïs, Pierre
During the past years, many innovations have been introduced to facilitate catheter ablation of post-myocardial infarction ventricular tachycardia. However, the predictors of outcome after ablation were not thoroughly studied. From 2009 to 2013, consecutive patients referred for post-myocardial infarction ventricular tachycardia ablation were included. The end point of the procedure was complete elimination of local abnormal ventricular activities (LAVA) and ventricular tachycardia (VT) noninducibility. The predictors of outcome with primary end point of VT recurrence were assessed. A total of 125 patients were included (age: 64±11 years; 7 women) for 142 procedures. The left ventricle was accessed via transseptal, retrograde aortic, and epicardial approaches in 87%, 33%, and 37% of patients, respectively. Three-dimensional electroanatomical mapping system was used in 70%, multipolar catheter in 51%, and real-time image integration in 38% (from magnetic resonance imaging in 39% and multidetector computed tomography in 93%) of patients. Before ablation, VT was inducible in 75%, and endocardial/epicardial LAVA were present in 88%/75%. After ablation, complete LAVA elimination was achieved in 60%, and VT noninducibility in 83%. During a median follow-up of 850 days (interquartile range, 439-1707), VT recurrence was observed in 36%. Multivariable analysis identified 3 independent outcome predictors: the ability to achieve complete LAVA elimination (R(2)=0.29; P<0.0001; risk ratio=0.52 [0.38-0.70]), the use of real-time image integration (R(2)=0.21; P=0.0006; risk ratio=0.49 [0.33-0.74]), and the use of multipolar catheters (R(2)=0.08; P=0.05; risk ratio=0.75 [0.56-1.00]). Achievement of complete LAVA elimination and use of scar integration from imaging and multipolar catheters to focus high-density mapping are independent predictors of VT-free survival after catheter ablation for post-myocardial infarction ventricular tachycardia. © 2016 American Heart Association
Komatsu, Yuki; Maury, Philippe; Sacher, Frédéric; Khairy, Paul; Daly, Matthew; Lim, Han S; Zellerhoff, Stephan; Jesel, Laurence; Rollin, Anne; Duparc, Alexandre; Mondoly, Pierre; Aurillac-Lavignolle, Valerie; Shah, Ashok; Denis, Arnaud; Cochet, Hubert; Derval, Nicolas; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre
This study sought to determine if the acute procedural outcome of ventricular tachycardia (VT) substrate ablation is associated with a mortality benefit in patients with implantable cardioverter-defibrillators (ICD). A total of 195 ICD recipients (65±11years) with ischemic or non-ischemic dilated cardiomyopathy underwent substrate-based ablation targeting elimination of local abnormal ventricular activities (LAVA). Acute procedural success, which was defined as elimination of all identified LAVA in addition to the lack of VT inducibility, was achieved in 95 (49%) patients. During a median follow-up of 23 months, patients with acute procedure success had a significantly lower incidence of ICD shocks compared to those with ablation failure (8% vs. 30%, p<0.001). In multivariate analysis, acute procedural success was associated with a lower risk of VT recurrence (hazard ratio [HR] 0.30, 95% confidence interval [CI] 0.18-0.49, P<0.001) and all-cause mortality (HR 0.32, 95%CI 0.17-0.60, P<0.001). While the impact of ablation success on mortality was not statistically significant in patients with LVEF>35% (HR 0.45, 95%CI 0.15-1.34, P = 0.15) and those with NYHA class I/II (HR 0.63, 95%CI 0.29-1.40, P = 0.26), it was marked in patients with LVEF≤35% (HR 0.30, 95%CI 0.14-0.62, P = 0.001) and NYHA class III/IV (HR 0.17, 95%CI 0.05-0.57, P = 0.004). LAVA elimination in addition to VT non-inducibility as a procedural outcome for substrate-based ablation is associated with reduced mortality and better VT-free survival during follow-up. This prognostic benefit may be most pronounced in patients with severe heart failure as indicated by severely depressed LV function and NYHA class III/IV symptoms. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Marine, Joseph E; Shetty, Veena; Chow, Grant V; Wright, Jeanette G; Gerstenblith, Gary; Najjar, Samer S; Lakatta, Edward G; Fleg, Jerome L
This study sought to determine the clinical predictors and prognostic significance of exercise-induced nonsustained ventricular tachycardia (NSVT) in a large population of asymptomatic volunteers. Prior studies have reported variable risk associated with exercise-induced ventricular arrhythmia. Subjects in the BLSA (Baltimore Longitudinal Study of Aging) free of known cardiovascular disease who completed at least 1 symptom-limited exercise treadmill test between 1977 and 2001 were included. NSVT episodes were characterized by QRS morphology, duration, and rate. Subjects underwent follow-up clinical evaluation every 2 years. The 2,099 subjects (mean age: 52 years; 52.2% male) underwent a mean of 2.7 exercise tests, in which 79 (3.7%) developed NSVT with exercise on at least 1 test. The median duration of NSVT was 3 beats (≤5 beats in 84%), and the median rate was 175 beats/min. Subjects with (vs. without) NSVT were older (67 ± 12 years vs. 51 ± 17 years, p < 0.0001) and more likely to be male (80% vs. 51%, p < 0.0001) and to have baseline electrocardiographic abnormalities (50% vs. 17%, p < 0.0001) or ischemic ST-segment changes with exercise (20% vs. 10%, p = 0.004). Over a mean follow-up of 13.5 ± 7.7 years, 518 deaths (24.6%) occurred. After multivariable adjustment for age, sex, and coronary risk factors, exercise-induced NSVT was not significantly associated with total mortality (hazard ratio: 1.30; 95% confidence interval: 0.89 to 1.90; p = 0.17). Exercise-induced NSVT occurred in nearly 4% of this asymptomatic adult cohort. This finding increased with age and was more common in men. After adjustment for clinical variables, exercise-induced NSVT did not independently increase the risk of total mortality. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Wu, Ming-Chya; Watanabe, Eiichi; Struzik, Zbigniew R.; Hu, Chin-Kun; Yamamoto, Yoshiharu
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.
Haissaguerre, M; Warin, J F; Lemétayer, P; Guillem, J P; Blanchot, P
Catheter electrical ablation of ventricular tachycardia (VT) was attempted in 31 patients (57 +/- 15 years) who had refractory recurrent VT. Fifteen patients had coronary artery disease, seven had arrhythmogenic right ventricular dysplasia, four had cardiomyopathy and five had no structural heart disease. Ten patients were NYHA class III-IV. Ten patients experienced cardiac arrest or syncope during VT. Twenty-two patients had only one documented morphologic type of spontaneous VT. Whereas nine patients had more than one: the VT was incessant or daily in 17 patients. One to 16 shocks (mean 5.6) of 160 to 240 joules each (1162 +/- 1060 joules) were delivered to the endocardial exit site of VT--as identified by endocardial activation mapping (29 patients) and pacemapping (31 patients)--during one (22 patients) or more than one session (nine patients). Cumulative delivered energy was 840 +/- 558 joules for right ventricular VT (11 patients) and 1362 +/- 1240 joules for left ventricular VT (20 patients). Reversible side effects occurring immediately after shocks included: nonclinical VT (two patients), ventricular fibrillation (two patients), AV block (three patients). Mean CK-MB fraction 6 hours after shocks was 91 +/- 46 IU/1. An electrophysiology study performed 7 to 10 days later demonstrated that the original clinical VT was inducible in seven patients, nonclinical monomorphic VT was inducible in eight patients and no VT was inducible in 13 patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Watanabe, Masaya; Yokoshiki, Hisashi; Mitsuyama, Hirofumi; Mizukami, Kazuya; Tsutsui, Hiroyuki
We describe the case of a 67-year-old woman with non-ischemic dilated cardiomyopathy who underwent successful radiofrequency catheter ablation for ventricular tachycardia (VT) originated from the isolated ventricular septal substrate. Pacemapping exhibited either left, identical to clinical VT, or right bundle branch block like wide QRS morphology. Time interval from the stimulus to QRS onset (St-QRS) was prolonged at the center of the substrate, while St-QRS at the border was shortened. Difference in the morphology of pacemapping was dependent on whether or not the pacing stimulus could propagate directly into the right ventricle due to the possible intramural conduction disturbance. Copyright © 2013 Elsevier Inc. All rights reserved.
Ciaccio, Edward J.; Coromilas, James; Ashikaga, Hiroshi; Cervantes, Daniel O.; Wit, Andrew L.; Peters, Nicholas S.; McVeigh, Elliot R.; Garan, Hasan
Background When the infarct border zone is stimulated prematurely, a unidirectional block line (UBL) can form and lead to double-loop (figure-of-eight) reentrant ventricular tachycardia (VT) with a central isthmus. The isthmus is composed of an entrance, center, and exit. It was hypothesized that for certain stimulus site locations and coupling intervals, the UBL would coincide with the isthmus entrance boundary, where infarct border zone thickness changes from thin-to-thick in the travel direction of the premature stimulus wavefront. Method A quantitative model was developed to describe how thin-to-thick changes in the border zone result in critically convex wavefront curvature leading to conduction block, which is dependent upon coupling interval. The model was tested in 12 retrospectively analyzed postinfarction canine experiments. Electrical activation was mapped for premature stimulation and for the first reentrant VT cycle. The relationship of functional conduction block forming during premature stimulation to functional block during reentrant VT was quantified. Results For an appropriately placed stimulus, in accord with model predictions: (1) The UBL and reentrant VT isthmus lateral boundaries overlapped (error: 4.8±5.7 mm). (2) The UBL leading edge coincided with the distal isthmus where the center-entrance boundary would be expected to occur. (3) The mean coupling interval was 164.6±11.0 ms during premature stimulation and 190.7±20.4 ms during the first reentrant VT cycle, in accord with model calculations, which resulted in critically convex wavefront curvature with functional conduction block, respectively, at the location of the isthmus entrance boundary and at the lateral isthmus edges. Discussion Reentrant VT onset following premature stimulation can be explained by the presence of critically convex wavefront curvature and unidirectional block at the isthmus entrance boundary when the premature stimulation interval is sufficiently short. The
Ciaccio, Edward J; Coromilas, James; Ashikaga, Hiroshi; Cervantes, Daniel O; Wit, Andrew L; Peters, Nicholas S; McVeigh, Elliot R; Garan, Hasan
When the infarct border zone is stimulated prematurely, a unidirectional block line (UBL) can form and lead to double-loop (figure-of-eight) reentrant ventricular tachycardia (VT) with a central isthmus. The isthmus is composed of an entrance, center, and exit. It was hypothesized that for certain stimulus site locations and coupling intervals, the UBL would coincide with the isthmus entrance boundary, where infarct border zone thickness changes from thin-to-thick in the travel direction of the premature stimulus wavefront. A quantitative model was developed to describe how thin-to-thick changes in the border zone result in critically convex wavefront curvature leading to conduction block, which is dependent upon coupling interval. The model was tested in 12 retrospectively analyzed postinfarction canine experiments. Electrical activation was mapped for premature stimulation and for the first reentrant VT cycle. The relationship of functional conduction block forming during premature stimulation to functional block during reentrant VT was quantified. For an appropriately placed stimulus, in accord with model predictions: (1) The UBL and reentrant VT isthmus lateral boundaries overlapped (error: 4.8±5.7mm). (2) The UBL leading edge coincided with the distal isthmus where the center-entrance boundary would be expected to occur. (3) The mean coupling interval was 164.6±11.0ms during premature stimulation and 190.7±20.4ms during the first reentrant VT cycle, in accord with model calculations, which resulted in critically convex wavefront curvature with functional conduction block, respectively, at the location of the isthmus entrance boundary and at the lateral isthmus edges. Reentrant VT onset following premature stimulation can be explained by the presence of critically convex wavefront curvature and unidirectional block at the isthmus entrance boundary when the premature stimulation interval is sufficiently short. The double-loop reentrant circuit pattern is a
Nearing, Bruce D; Wellenius, Gregory A; Mittleman, Murray A; Josephson, Mark E; Burger, Andrew J; Verrier, Richard L
A critical need exists for reliable warning markers of in-hospital life-threatening arrhythmias. We used a new quantitative method to track interlead heterogeneity of depolarization and repolarization to detect premonitory changes before ventricular tachycardia (VT) in hospitalized patients with acute decompensated heart failure. Ambulatory ECGs (leads V(1), V(5), and aVF) recorded before initiation of drug therapy from patients enrolled in the PRECEDENT (Prospective Randomized Evaluation of Cardiac Ectopy with Dobutamine or Nesiritide Therapy) trial were analyzed. R-wave heterogeneity (RWH) and T-wave heterogeneity (TWH) were assessed by second central moment analysis and T-wave alternans (TWA) by modified moving average analysis. Of 44 patients studied, 22 had experienced episodes of VT (≥4 beats at heart rates >100 beats/min) following ≥120 minutes of stable sinus rhythm, and 22 were age- and sex-matched patients without VT. TWA increased from 18.6±2.1 μV (baseline, mean±SEM) to 27.9±4.6 μV in lead V(5) at 15 to 30 minutes before VT (P<0.05) and remained elevated until the arrhythmia occurred. TWA results in leads V(1) and aVF were similar. RWH and TWH were elevated from 164.1±33.1 and 134.5±20.6 μV (baseline) to 299.8±54.5 and 239.2±37.0 μV at 30 to 45 minutes before VT (P<0.05), respectively, preceding the crescendo in TWA by 15 minutes. Matched patients without VT did not display elevated RWH (185.5±29.4 μV) or TWH (157.1±27.2 μV) during the 24-hour period. This investigation is the first clinical demonstration of the potential utility of tracking depolarization and repolarization heterogeneity to detect crescendos in electrical instability that could forewarn of impending nonsustained VT. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00270400.
Agir, Aysen Agacdiken; Celikyurt, Umut; Karauzum, Kurtulus; Yilmaz, Irem; Ozbudak, Ersan; Bozyel, Serdar; Kanko, Muhip; Vural, Ahmet; Ural, Dilek
The Fontan operation is the primary surgical technique used for palliation of patients with single-ventricle physiology. Arrhythmias are frequently observed and associated with morbidity and mortality in Fontan patients. The frequency of arrhythmias after the Fontan procedure increases over time and it was reported to reach 50% in a 20-year follow up. Atrial tachyarrhythmias, especially atrial tachycardia and sinus bradycardia, are most frequently observed in these patients. Ventricular arrhythmias are rarely observed. Generally, medical therapy, catheter ablation, pacemaker or implantable cardioverter defibrillator (ICD) implantation are options in the treatment of these arrhythmias. It may be difficult to implant either a pacemaker or an ICD in patients on whom the Fontan procedure has been performed. In conditions where access to the right ventricle is from the venous system, it is anatomically impossible. Where there is no functional right ventricle, device implantation can be performed with alternative methods other than the conventional transvenous approach. In this report, we discuss a middle-aged woman with a Fontan operation performed 14 years earlier, who presented with ventricular tachycardia (VT) and in whom an epicardial ICD was implanted. The literature on this issue is also reviewed.
Nof, Eyal; Belhassen, Bernard; Arad, Michael; Bhuiyan, Zahurul A.; Antzelevitch, Charles; Rosso, Raphael; Fogelman, Rami; Luria, David; Eli-Ani, Dalia; Mannens, Marcel M.A.M.; Viskin, Sami; Eldar, Michael; Wilde, Arthur A.M.; Glikson, Michael
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease for which electrophysiological studies (EPS) have shown to be of limited value. Objective We present a CPVT family in which marked post-pacing repolarization abnormalities during EPS were the only consistent phenotypic manifestation of RyR2 mutation carriers. Methods The study was prompted by the observation of transient marked QT prolongation preceding initiation of ventricular fibrillation during atrial fibrillation in a boy with a family history of sudden cardiac death (SCD). Family members underwent exercise and pharmacologic ECG testing with epinephrine, adenosine and flecainide. Non-invasive clinical tests were normal in 10 patients evaluated, except for both epinephrine and exercise-induced ventricular arrhythmias in 1. EPS included bursts of ventricular pacing and programmed ventricular extrastimulation reproducing short-long sequences. Genetic screening involved direct sequencing of genes involved in LQTS as well as RyR2. Results Six patients demonstrated a marked increase in QT interval only in the first beat after cessation of ventricular pacing and/or extrastimulation. All 6 patients were found to have a heterozygous missense mutation (M4109R) in RyR2. Two of them, presenting with aborted SCD also had a second missense mutation (I406T- RyR2). Four family members without RyR2 mutations did not display prominent post-pacing QT changes. Conclusions M4109R- RyR2 is associated with a high incidence of SCD. The contribution of I406T to the clinical phenotype is unclear. In contrast to exercise testing, marked post-pacing repolarization changes in a single beat accurately predicted carriers of M4109R- RyR2 in this family. PMID:21699856
Izquierdo, Maite; Sánchez-Gómez, Juan Miguel; Ferrero de Loma-Osorio, Angel; Martínez, Angel; Bellver, Alejandro; Peláez, Antonio; Núñez, Julio; Núñez, Carlos; Chorro, Javier; Ruiz-Granell, Ricardo
Epicardial ablation has shown improvement in clinical outcomes of patients with ischemic heart disease (IHD) after ventricular tachycardia (VT) ablation. However, usually epicardial access is only performed when endocardial ablation has failed. Our aim was to compare the efficacy of endocardial+epicardial ablation versus only endocardial ablation in the first procedure in patients with IHD. Fifty-three patients with IHD, referred for a first VT ablation to our institution, from 2012 to 2014, were included. They were divided in 2 groups according to enrollment time: from May 2013, we started to systematically perform endo-epicardial access (Epi-Group) as first-line approach in consecutive patients with IHD (n=15). Patients who underwent only an endocardial VT ablation in their first procedure (Endo-Group) included patients with previous cardiac surgery and the historical (before May 2013; n=35). All late-potentials in the scar zone were eliminated, and if VT was tolerated, critical isthmuses were also approached. The end point was the noninducibility of any VT. During a median follow-up of 15±10 months, the combined end point (hospital or emergency admission because of a ventricular tachycardia or reablation) occurred in 14 patients of the Endo-group and in one patient in the Epi-group (event-free survival curves by Grey-test, P=0.03). Ventricular arrhythmia recurrences occurred in 16 and in 3 patients in the Endo and Epi-Group, respectively (Grey-test, P=0.2). A combined endocardial-epicardial ablation approach for initial VT ablation was associated with fewer readmissions for VT and repeat ablations. Further studies are warranted. © 2015 American Heart Association, Inc.
Prognostic value of non-sustained ventricular tachycardia and the potential role of amiodarone treatment in hypertrophic cardiomyopathy: assessment in an unselected non-referral based patient population
Cecchi, F; Olivotto, I; Montereggi, A; Squillatini, G; Dolara, A; Maron, B
Background—Amiodarone has been reported to reduce the likelihood of sudden death in patients with hypertrophic cardiomyopathy (HCM). However, data regarding the clinical course in HCM have traditionally come from selected referral populations biased toward assessment of high risk patients. Aims—To evaluate antiarrhythmic treatment for sudden death in an HCM population not subject to tertiary referral bias, closely resembling the true disease state present in the community. Methods—Cardiovascular mortality was assessed in relation to the occurrence of non-sustained ventricular tachycardia (NSVT) on 24 or 48 hour ambulatory Holter recording, a finding previously regarded as a marker for sudden death, particularly when the arrhythmia was frequent, repetitive or prolonged. 167 consecutive patients were analysed by multiple Holter ECG recordings (mean (SD) 157 (129) hours) and followed for a mean of 10 (5) years. Only patients with multiple repetitive NSVT were treated with amiodarone, and in relatively low doses (220 (44) mg/day). Results—Nine HCM related deaths occurred: 8 were the consequence of congestive heart failure, but only 1 was sudden and unexpected. Three groups of patients were segregated based on their NSVT profile: group 1 (n = 39), multiple (⩾ 2 runs) and repetitive bursts (on ⩾ 2 Holters) of NSVT, or prolonged runs of ventricular tachycardia, included 4 deaths due to heart failure; group 2 (n = 38), isolated infrequent bursts of NSVT, included 1 sudden death; group 3 (n = 90), without NSVT, included 4 heart failure deaths. Kaplan-Meier survival analysis showed no significant differences in survival between the three groups throughout follow up. Conclusions—In an unselected patient population with HCM, isolated, non-repetitive bursts of NSVT were not associated with adverse prognosis and so this arrhythmia does not appear to justify chronic antiarrhythmic treatment. Amiodarone, administered in relatively low
Prophylactic catheter ablation of ventricular tachycardia before cardioverter-defibrillator implantation in patients with non-ischemic cardiomyopathy: Clinical outcomes after a single endocardial ablation.
Suzuki, Atsushi; Yoshida, Akihiro; Takei, Asumi; Fukuzawa, Koji; Kiuchi, Kunihiko; Takami, Kaoru; Itoh, Mitsuaki; Imamura, Kimitake; Fujiwara, Ryudo; Nakanishi, Tomoyuki; Yamashita, Soichiro; Matsumoto, Akinori; Shimane, Akira; Okajima, Katsunori; Hirata, Ken-Ichi
Outcomes related to prophylactic catheter ablation (PCA) for ventricular tachycardia (VT) before implantable cardioverter-defibrillator (ICD) implantation in non-ischemic cardiomyopathy (NICM) are not well characterized. We assessed the efficacy of single endocardial PCA in NICM patients. We retrospectively analyzed 101 consecutive NICM patients with sustained VT. We compared clinical outcomes of patients who underwent PCA (ABL group) with those who did not (No ABL group). Successful PCA was defined as no inducible clinical VT. We also compared the clinical outcomes of patients with successful PCA (PCA success group) with those of the No ABL group. Endpoints were appropriate ICD therapy (shock and anti-tachycardia pacing) and the occurrence of electrical storm (ES). PCA was performed in 42 patients, and it succeeded in 20. The time to ES occurrence was significantly longer in the ABL group than in the No ABL group (p=0.04). The time to first appropriate ICD therapy and ES occurrence were significantly longer in the PCA success group than in the No ABL group (p=0.02 and p<0.01, respectively). Single endocardial PCA can decrease ES occurrence in NICM patients. However, high rates of VT recurrence and low success rates are issues to be resolved; therefore, the efficacy of single endocardial PCA is currently limited.
Prophylactic catheter ablation of ventricular tachycardia before cardioverter-defibrillator implantation in patients with non-ischemic cardiomyopathy: Clinical outcomes after a single endocardial ablation
Suzuki, Atsushi; Yoshida, Akihiro; Takei, Asumi; Fukuzawa, Koji; Kiuchi, Kunihiko; Takami, Kaoru; Itoh, Mitsuaki; Imamura, Kimitake; Fujiwara, Ryudo; Nakanishi, Tomoyuki; Yamashita, Soichiro; Matsumoto, Akinori; Shimane, Akira; Okajima, Katsunori; Hirata, Ken-ichi
Background Outcomes related to prophylactic catheter ablation (PCA) for ventricular tachycardia (VT) before implantable cardioverter-defibrillator (ICD) implantation in non-ischemic cardiomyopathy (NICM) are not well characterized. We assessed the efficacy of single endocardial PCA in NICM patients. Methods We retrospectively analyzed 101 consecutive NICM patients with sustained VT. We compared clinical outcomes of patients who underwent PCA (ABL group) with those who did not (No ABL group). Successful PCA was defined as no inducible clinical VT. We also compared the clinical outcomes of patients with successful PCA (PCA success group) with those of the No ABL group. Endpoints were appropriate ICD therapy (shock and anti-tachycardia pacing) and the occurrence of electrical storm (ES). Results PCA was performed in 42 patients, and it succeeded in 20. The time to ES occurrence was significantly longer in the ABL group than in the No ABL group (p=0.04). The time to first appropriate ICD therapy and ES occurrence were significantly longer in the PCA success group than in the No ABL group (p=0.02 and p<0.01, respectively). Conclusion Single endocardial PCA can decrease ES occurrence in NICM patients. However, high rates of VT recurrence and low success rates are issues to be resolved; therefore, the efficacy of single endocardial PCA is currently limited. PMID:26336545
Wydrzyński, Jacek; Jankowski, Stanisław; Piątkowska-Janko, Ewa
This paper presents the application of neural networks to the risk recognition of sustained ventricular tachycardia and flicker in patients after myocardial infarction based on high-resolution electrocardiography. This work is based on dataset obtained from the Medical University of Warsaw. The studies were performed on one multiclass classifier and on binary classifiers. For each case the optimal number of hidden neurons was found. The effect of data preparation: normalization and the proper selection of parameters was considered, as well as the influence of applied filters. The best neural classifier contains 5 hidden neurons, the input ECG signal is represented by 8 parameters. The neural network classifier had high rate of successful recognitions up to 90% performed on the test data set.
Pavlova, M; Lupoglazoff, J M; Denjoy, I; Luton, D; Magnier, S; Casasoprana, A; Azancot, A
The authors report two cases of foetal supraventricular tachycardia in healthy hearts with 1/1 atrioventricular conduction which turned out to be atrial tachycardias in the postnatal period. The first foetus had permanent tachycardia at 190/minute at 34 weeks' amenorrhea with left ventricular dysfunction at 36 weeks. In the postnatal period, treatment with digoxine and amiodarone restored sinus rhythm and normal left ventricular function. Permanent foetal tachycardia, even at a rate of less than 200 beats/minute, should suggest an arrhythmia and may lead to left ventricular dysfunction in utero. The other foetus had an aneurysm of the foramen ovale with paroxysmal tachycardias at 220/minute without cardiac dysfunction. A Holter at 1 month showed paroxysmalatrial tachycardia. Postnatal rhythm monitoring is necessary in paroxysmal foetus tachycardia, especially with prenatal aneurysm of the foramen ovale.
Irie, Tadanobu; Yu, Ricky; Bradfield, Jason S.; Vaseghi, Marmar; Buch, Eric F.; Ajijola, Olujimi; Macias, Carlos; Fujimura, Osamu; Mandapati, Ravi; Boyle, Noel G.; Shivkumar, Kalyanam; Tung, Roderick
Background It is not known if the most delayed late potentials are functionally most specific for scar-related ventricular tachycardia (VT) circuits. Methods and Results Isochronal late activation maps (ILAM) were constructed to display ventricular activation during sinus rhythm over eight isochrones. Analysis was performed at successful VT termination sites and prospectively tested. 33 patients with 47 scar-related VTs where a critical site was demonstrated by termination of VT during ablation were retrospectively analyzed. In those that underwent mapping of multiple surfaces, 90% of critical sites were on the surface that contained the latest late potential. However, only 11% of critical sites were localized to the latest isochrone (87.5–100%) of ventricular activation. The median percentage of latest activation at critical sites was 78% at a distance from the latest isochrone of 18 mm. Sites critical to reentry were harbored in regions with slow conduction velocity, where 3 isochrones were present within a 1 cm radius. 10 consecutive patients underwent ablation prospectively guided by ILAM, targeting concentric isochrones outside of the latest isochrone. Elimination of the targeted VT was achieved in 90%. Termination of VT was achieved in 6 patients at a mean ventricular activation percentage of 78%, with only 1 requiring ablation in the latest isochrone. Conclusions Late potentials identified in the latest isochrone of activation during sinus rhythm are infrequently correlated with successful ablation sites for VT. The targeting of slow conduction regions propagating into the latest zone of activation may be a novel and promising strategy for substrate modification. PMID:25740836
Bourke, J; Campbell, R; McComb, J; Furniss, S; Doig, J; Hilton, C
OBJECTIVE—To report outcome following surgery for postinfarction ventricular tachycardia undertaken in patients before the use of implantable defibrillators. DESIGN—A retrospective review, with uniform patient selection criteria and surgical and mapping strategy throughout. Complete follow up. Long term death notification by OPCS (Office of Population Censuses and Statistics) registration. SETTING—Tertiary referral centre for arrhythmia management. PATIENTS—100 consecutive postinfarction patients who underwent map guided endocardial resection at this hospital in the period 1981-91 for drug refractory ventricular tachyarrhythmias. RESULTS—Emergency surgery was required for intractable arrhythmias in 28 patients, and 32 had surgery within eight weeks of infarction ("early"). Surgery comprised endocardial resections in all, aneurysmectomy in 57, cryoablations in 26, and antiarrhythmic ventriculotomies in 11. Twenty five patients died < 30 days after surgery, 21 of cardiac failure. This high mortality reflects the type of patients included in the series. Only 12 received antiarrhythmic drugs after surgery. Perioperative mortality was related to preoperative left ventricular function and the context of surgery. Mortality rates for elective surgery more than eight weeks after infarction, early surgery, emergency surgery, and early emergency surgery were 18%, 31%, 46%, and 50%, respectively. Actuarial survival rates at one, three, five, and 10 years after surgery were 66%, 62%, 57%, and 35%. CONCLUSIONS—Surgery offers arrhythmia abolition at a risk proportional to the patient's preoperative risk of death from ventricular arrhythmias. The long term follow up results suggest a continuing role for surgery in selected patients even in the era of catheter ablation and implantable defibrillators. Keywords: arrhythmias; myocardial infarction; surgical management PMID:10409528
Culić, Viktor; Eterović, Davor; Mirić, Dinko; Giunio, Lovel; Lukin, Ajvor; Fabijanić, Damir
A circadian pattern with a morning peak and the triggering role of emotional stress have been suggested for ventricular arrhythmias. After controlling for participant baseline characteristics and medication used, the authors studied the association of emotional upset, physical activity, and meteorologic parameters with occurrence of ventricular tachycardia (VT) in 457 Croatian participants aged 11-88 years consecutively assigned to undergo continuous 24-hour Holter monitoring. In 2001, multivariate analysis of possible VT precipitators was performed separately for men, women, those aged <65 years, and those aged >64 years. A U-shaped pattern of wind speed (either very weak or very strong), rising relative air moisture, falling atmospheric pressure, and emotional upset were independent predictors of VT episodes in all participant subgroups. Positive association of VT with higher atmospheric temperature or pressure was observed in women and elderly. After adjustment for external triggers, a circadian variation in VT episodes persisted in women (p = 0.01) and those aged <65 years (p < 0.0001) only. A protective effect of beta-blockers and anxiolytics was especially apparent for men and elderly, as well as an adverse effect of digitalis in women. Results suggest that meteorologic and emotional stress could be considered external triggers of VT, with age- and sex-dependent susceptibility.
Lujan, Heidi L.; Chen, Ying; DiCarlo, Stephen E.
Midthoracic spinal cord injury is associated with ventricular arrhythmias that are mediated, in part, by enhanced cardiac sympathetic activity. Furthermore, it is well known that sympathetic neurons have a lifelong requirement for nerve growth factor (NGF). NGF is a neurotrophin that supports the survival and differentiation of sympathetic neurons and enhances target innervation. Therefore, we tested the hypothesis that paraplegia is associated with an increased cardiac NGF content, sympathetic tonus, and susceptibility to ischemia-induced ventricular tachyarrhythmias. Intact and paraplegic (6–9 wk posttransection, T5 spinal cord transection) rats were instrumented with a radiotelemetry device for recording arterial pressure, temperature, and ECG, and a snare was placed around the left main coronary artery. Following recovery, the susceptibility to ventricular arrhythmias (coronary artery occlusion) was determined in intact and paraplegic rats. In additional groups of matched intact and paraplegic rats, cardiac nerve growth factor content (ELISA) and cardiac sympathetic tonus were determined. Paraplegia, compared with intact, increased cardiac nerve growth factor content (2,146 ± 286 vs. 180 ± 36 pg/ml, P < 0.05) and cardiac sympathetic tonus (154 ± 4 vs. 68 ± 4 beats/min, P < 0.05) and decreased the ventricular arrhythmia threshold (3.6 ± 0.2 vs. 4.9 ± 0.2 min, P < 0.05). Thus altered autonomic behavior increases the susceptibility to ventricular arrhythmias in paraplegic rats. PMID:19286942
Device Artifact Reduction for Magnetic Resonance Imaging of Patients with Implantable Cardioverter Defibrillators and Ventricular Tachycardia: Late Gadolinium Enhancement Correlation with Electroanatomical Mapping
Stevens, Steven M; Tung, Roderick; Rashid, Shams; Gima, Jean; Cote, Shelly; Pavez, Geraldine; Khan, Sarah; Ennis, Daniel B; Finn, J. Paul; Boyle, Noel; Shivkumar, Kalyanam; Hu, Peng
Background Late Gadolinium Enhancement (LGE) MRI of ventricular scar has been shown to be accurate for detection and characterization of arrhythmia substrates. However, the majority of patients referred for ventricular tachycardia (VT) ablation have an implantable cardioverter defibrillator (ICD), which obscures image integrity and the clinical utility of MRI. Objective To develop and validate a wideband LGE MRI technique for device artifact removal. Methods A novel wideband LGE MRI technique was developed to allow for improved scar evaluation on patients with ICDs. The wideband technique and the standard LGE MRI were tested on 18 patients with ICDs. VT ablation was performed in 13 of 18 patients with either endocardial and/or epicardial approach and the correlation between the scar identified on MRI and electroanatomical mapping was analyzed. Results Hyper-intensity artifact was present in 16/18 of patients using standard MRI, which was eliminated using the wideband LGE and allowed for MRI interpretation in 15/16 patients. All patients had ICD lead characteristics confirmed as unchanged post- MRI and had no adverse events. LGE scar was seen in 11/18 patients. Among the 15 patients where wideband LGE allowed visualization of myocardium, 10 had LGE scar and 5 had normal myocardium in the regions with image artifacts when using the standard LGE. The left ventricular scar size measurements using wideband MRI and EAM were correlated with R2=0.83, P=0.00003. Conclusions The wideband LGE-MRI improves the ability to visualize myocardium for clinical interpretation, which correlated well with EAM findings during VT ablation. PMID:24140812
Rosas Peralta, M; Casanova Garcés, J M; González Hermosillo, J A
The most common cause of sudden death is malignant ventricular arrhytHmia. In order to identify the predictive value of the vectospatial evaluation in the surface electrocardiogram during a monomorphic ventricular tachycardia (MVT), and the equilibrium state of AutonomOus Nervous System (ANS), 89 patients of both sexes were studied with mean age of 47 +/- 16.2 years. They were grouped as follows: Group I included 43 patients (P), with a coronary heart disease; Group II (n = 24P) with a noncoronary myocardiopathy and Group III (n = 22P) with unknown origin MVT (Cryptogenic). Relationship between QRS configuration in the frontal plane (QRSf) during MVT episode with transverse plane, cardiac position in the chest X-rays, presence and duration of late potentials (LPs) in their two types of analysis (time domain and spectral mapping by high-resolution electrocardiogram), heart rate variability and ejection fraction by echocardiography were determined in all patients. The QRSf configuration with left bundle-branch block (LBBB) was the most common in group I, the sustained MVT (SMVT) + LBBB was associated with both prevalence and duration of late potentials (p = 0.005), low-rate heart variability and ejection fraction < 40%. SMVT + LBBB was the most common type in group III and if it has shown and inferior axis, an elevated rate of LPs (+) was seen. Situation that oriented to an arrhythmogenic right ventricular dysplasia. Low amplitude signals with short duration in the time domain were seen in group I with LBBB; and with SMVT + RBBB in group II. We suggest that vectospatial evaluation of QRSf during a MVT is a greater importance in the risk stratification for sudden death and it can guide to anatomic origin and the diagnosis-therapeutic approach.
Beyond the Storm: Comparison of Clinical Factors, Arrhythmogenic Substrate, and Catheter Ablation Outcomes in Structural Heart Disease Patients With versus Those Without a History of Ventricular Tachycardia Storm.
Kumar, Saurabh; Fujii, Akira; Kapur, Sunil; Romero, Jorge; Mehta, Nishaki K; Tanigawa, Shinichi; Epstein, Laurence M; Koplan, Bruce A; Michaud, Gregory F; John, Roy M; Stevenson, William G; Tedrow, Usha B
Catheter ablation can be lifesaving in ventricular tachycardia (VT) storm, but the underlying substrate in patients with storm is not well characterized. We sought to compare the clinical factors, substrate, and outcomes differences in patients with sustained monomorphic VT who present for catheter ablation with VT storm versus those with a nonstorm presentation. Consecutive ischemic (ICM; n = 554) or nonischemic cardiomyopathy patients (NICM; n = 369) with a storm versus nonstorm presentation were studied (ICM storm 186; NICM storm 101). In ICM, storm compared with nonstorm patients had significantly lower left ventricular (LV) ejection fraction (EF), greater number of antiarrhythmic drug (AAD) failures, slower VTs, greater number of scarred LV segments, higher incidence of anterior, septal, and apical endocardial LV scar (all P < 0.05). However, outcomes in follow-up were similar (12-month ventricular arrhythmia [VA]-free survival: 51% vs. 52%, P = 0.6; survival free of death/transplant 75% vs. 87%, P = 0.7). In addition to the above differences, NICM storm patients were also older; however, the extent and distribution of scar was similar except for a higher incidence of lateral endocardial scar in storm patients (P = 0.05). VA-free survival (36% vs. 47%, P = 0.004) and survival free of death/transplant, however, were worse in NICM storm than nonstorm patients (72% vs. 88%, P = 0.001). NICM storm patients had worse VA-free survival than ICM storm patients. There are differences in clinical factors and scar patterns in patients undergoing VT ablation who present with VT storm versus those with a nonstorm presentation. Clinical outcomes are worse in NICM storm patients. © 2016 Wiley Periodicals, Inc.
Nishizaki, M; Arita, M; Sakurada, H; Ashikaga, T; Yamawake, N; Numano, F; Hiraoka, M
During VT of QRS morphology with right bundle branch block and left axis deviation in a patient without obvious structural heart disease, entrainment by pacing from the right ventricular outflow tract and high right atrium was demonstrated. During entrainment of VT, a Purkinje potential preceding the QRS and recorded at the left ventricular mid-septum was activated by orthodromic impulses in the reentry circuit. The interval between the Purkinje potential and the earliest left ventricular activation was decrementally prolonged with shortening of pacing cycle length. Radiofrequency energy was applied to this site, resulting in successful elimination of VT. Therefore, the Purkinje potential represented activation by an orthodromic wavefront in the reentry circuit, while the orthodromically distal site to this potential showed an area of slow conduction with decremental property.
Nakayama, Masafumi; Saito, Atsushi; Kitazawa, Hitoshi; Takahashi, Minoru; Sato, Masahito; Fuse, Koichi; Okabe, Masaaki; Hoshino, Kou; Tanaka, Nobuhiro; Yamashina, Akira; Aizawa, Yoshifusa
Papaverine is used for the evaluation of functional status of the coronary arteries but it may provoke severe ventricular tachyarrhythmias (VTAs). This study compared the clinical and ECG characteristic of patients with papaverine-induced VTAs. The study involved 25 patients who underwent a fractional flow reserve (FFR) study. FFR was determined as the ratio of blood pressure at the distal and the proximal site of stenosis after intracoronary papaverine administration at 12 mg into the left and 8 mg into the right coronary artery. The QT and QTU intervals were measured manually in the limb leads and in the precordial leads, respectively and corrected by the R-R interval to obtain QTc and QTUc. The clinical and ECG data were compared between the patient groups with and without VTAs. After papaverine administration into the left (20), right (3) or both coronary arteries (2), the RR interval shortened, but non-significantly however, the QT interval (and QTc) and the QTU interval (and QTUc) were significantly prolonged. VTAs developed in four women: torsade de pointes in 3 followed by ventricular fibrillation and ventricular premature beats in 1 patient. After papaverine administration, QTU and QTUc were more prolonged in women than men and in patients with VTAs compared to those without. Just prior to VTAs, giant T-U waves were observed. Intracoronary papaverine was used to determine FFR which may induce VTAs. VTAs developed only in women and they were closely related to prolongation of the QTU intervals with prominent T-U waves.
Dinov, Borislav; Arya, Arash; Schratter, Alexandra; Schirripa, Valentina; Fiedler, Lukas; Sommer, Philipp; Bollmann, Andreas; Rolf, Sascha; Piorkowski, Christopher; Hindricks, Gerhard
Data on outcomes after catheter ablation of ventricular tachycardia (VT) in patients with nonischemic dilated cardiomyopathy (NIDCM) are insufficient. We aimed to investigate the effects of successful catheter ablation of VT on cardiac mortality in patients with NIDCM. One hundred two patients with NIDCM (86 men; mean age, 58.8±15.2 years; mean ejection fraction, 33.3±11.9%) underwent VT ablation. After catheter ablation, a programmed ventricular stimulation to test for success was performed. Complete VT noninducibility was achieved in 62 (61%) patients and partial success or failure in 32 (31%) patients. During 2 years of follow-up, VT recurrence was observed in 33 patients (53%) without inducible VTs and in 24 patients (75%) with inducible VT inducible (P=0.041). VT inducibility was associated with higher VT recurrence (adjusted hazard ratio, 1.84; 95% confidence interval, 1.08-3.13; P=0.025). The primary end point of all-cause mortality was reached in 9 patients (15%) with noninducible VTs versus 11 patients (34%) with inducible sustained VTs (P=0.026). VT inducibility was associated with all-cause mortality (adjusted hazard ratio, 2.73; 95% confidence interval, 1.003-7.43; P=0.049). In patients with NIDCM and recurrent sustained VTs, a complete ablation of all inducible VTs may be achieved in 60% of the cases. The complete noninducibility may be a preferable end point of ablation because it was associated with better long-term success. Importantly, if possible to achieve through ablation, a complete VT noninducibility was associated with reduction of the likelihood for all-cause mortality in patients with NIDCM. © 2015 American Heart Association, Inc.
Olsen, Jan-Aage; Brunborg, Cathrine; Steinberg, Mikkel; Persse, David; Sterz, Fritz; Lozano, Michael; Westfall, Mark; Travis, David T; Lerner, E Brooke; Brouwer, Marc A; Wik, Lars
Shorter manual chest compression pauses prior to defibrillation attempts is reported to improve the defibrillation success rate. Mechanical load-distributing band (LDB-) CPR enables shocks without compression pause. We studied pre-shock pause and termination of ventricular fibrillation/pulseless ventricular tachycardia 5s post-shock (TOF) and return of organized rhythm (ROOR) with LDB and manual (M-) CPR. In a secondary analysis from the Circulation Improving Resuscitation Care trial, patients with initial shockable rhythm and interpretable post-shock rhythms were included. Pre-shock rhythm, pause duration (if any), and post-shock rhythm were obtained for each shock. Associations between TOF/ROOR and pre-shock pause duration, including no pause shocks with LDB-CPR, were analyzed with Chi-square test. A p-value <0.05 was considered statistically significant. For TOF and ROOR analyses we included 417 LDB-CPR patients with 1476 and 1438 shocks, and 495 M-CPR patients with 1839 and 1796 shocks, respectively. For first shocks with LDB-CPR, pre-shock pause was associated with TOF (p=0.049) with lowest TOF (77%) for shocks given without pre-shock compression pause. This association was not significant when all shocks were included (p=0.07) and not for ROOR. With M-CPR there were no significant associations between shock-related chest compression pause duration and TOF or ROOR. For first shocks with LDB-CPR, termination of fibrillation was associated with pre-shock pause duration. There was no association for the rate of return of organized rhythm. For M-CPR, where no shocks were given during continuous chest compressions, there were no associations between pre-shock pause duration and TOF or ROOR. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Pitschner, H F; Neuzner, J
The first report about successful radio frequency ablation of a right-posterior-septal accessory pathway appeared in 1986. Since then, the technology of both guidable ablation catheters and radio frequency generators has been considerably improved in an initially clinical-experimental phase. At the same time, electrophysiologists were equally able to enlarge their knowledge in the field of signal characteristics of arrhythmogenic substrates. This included the discovery of action potentials of accessory pathways (preexcitation syndromes), the location of fast and slow AV node conduction (AV nodal reentrant tachycardia, AVNRT), the functional importance of the anatomical isthmus between the os of the coronary sinus, the tricuspid valve and the inferior caval vein (atrial flutter). Mapping techniques such as transient and concealed entrainment became, among others, significant tools in finding the best localization for radio frequency catheter ablation. Thus, technical development and the increased knowledge of clinical electrophysiologists resulted in firmly establishing the procedure of catheter ablation as the method of first choice in the curative treatment of supraventricular tachycardias in a potential collective of about 5 per mill of the normal population (without atrial fibrillation). Supraventricular tachycardias with a reentry mechanism in the broadest sense (> 95% of all pts. with SVT) and those with focal automaticity (< 5%) occur as atrial fibrillation or atrial flutter in about 60% of all pts. (4-6 per mill of the normal population). Manifestation of the remaining reentrant tachycardias is mainly in the form of AVNRT (retrograde conduction via the fast pathway > 90% versus uncommon type < 10%). AV reentry via accessory pathways is found in about 15%, with orthodromic conduction via the AV node (> 90%). Atrial reentrant tachycardias are rather rare (with the exception of atrial fibrillation/flutter). The literature suggests medical therapy to be
The use of a novel signal analysis to identify the origin of idiopathic right ventricular outflow tract ventricular tachycardia during sinus rhythm: Simultaneous amplitude frequency electrogram transformation mapping
Chung, Fa-Po; Lin, Chin-Yu; Lo, Men-Tzung; Liu, Che-An; Lin, Chen; Chang, Yi-Chung; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Tuan, Ta-Chuan; Chao, Tze-Fan; Liao, Jonan; Chang, Yao-Ting; Lin, Chung-Hsing; Hung, Yuan; Yamada, Shinya; Pan, Kuo-Li; Lin, Yenn-Jiang; Chen, Shih-Ann
Introduction The signal characteristics of intracardiac bipolar electrograms at the origin of idiopathic RVOT-VT during sinus rhythm remain unclear. Objective The study sought to develop a novel real-time/online technique, simultaneous amplitude frequency electrogram transformation (SAFE-T), to quantify and localize the diseased ventricular substrate in idiopathic RVOT-VT. Methods We retrospectively investigated the intracardiac bipolar recordings in 70 consecutive patients (26% male, mean age 42±12 years) who underwent successful radiofrequency catheter ablation of idiopathic RVOT-VT. We quantified the extent of the frequency fraction of ventricular potentials during sinus rhythm or ventricular pacing using a novel formula, the product of instantaneous amplitude and frequency, and showed that in a 3D geometry as an online SAFE-T map. Results The characteristics of the HHT spectra of electrograms derived from VT origins demonstrated high frequency components (>70 Hz), which were independent of the rhythm. The density of the abnormal potentials at the VT origins were higher (VT origins, 7.5±2.3 sites/cm2 vs. surrounding myocardium, 1.5±1.3 sites/cm2, p<0.001), and were significantly decreased after ablation (0.7±0.6 sites/cm2, p<0.001). A small region of abnormal potentials were observed in the VT origins (mean area of 1.5±0.8 cm2). The SAFE-T maps predicted the VT origins with 92% sensitivity, 78% specificity with optimal cut-off value of >3.0 Hz·mV. Conclusion The online SAFE-T map was feasible for quantifying the diseased ventricular substrate, irrespective of the rhythm of activation, and can be used to identify the optimal ablation targets for idiopathic RVOT-VT. We found a limited region of abnormal potentials where the RVOT-VT origins were successfully ablated. PMID:28282453
Dubi, Shay; Dubi, Chen; Dubi, Yonatan
A minimal model for mechanical motion of the left ventricle is proposed. The model assumes the left ventricle to be a harmonic oscillator with two distinct phases, simulating the systolic and diastolic phases, at which both the amplitude and the elastic constant of the oscillator are different. Taking into account the pressure within the left ventricle, the model shows qualitative agreement with functional parameters of the left ventricle. The model allows for a natural explanation of heart failure with preserved systolic left ventricular function, also termed diastolic heart failure. Specifically, the rise in left ventricular filling pressures following increased left-ventricular wall stiffness is attributed to a mechanism aimed at preserving heart rate and cardiac output.
Mallidi, Jaya; Nadkarni, Girish N.; Berger, Ronald D.; Calkins, Hugh; Nazarian, Saman
Background Most studies of catheter ablation for treatment of ventricular tachycardia (VT) are relatively small observational trials. Objectives To define the relative risk of VT recurrence in patients undergoing catheter ablation as an adjunct to medical therapy versus medical therapy alone in a pooled analysis of controlled studies. Methods Randomized and non-randomized controlled trials of patients who underwent adjunctive catheter ablation of VT versus medical therapy alone were sought. MEDLINE, EMBASE, the Cochrane Central register of controlled trials (CENTRAL), and Web of Science were searched from 1965 to July 2010. Supplemental searches included Internet resources, reference lists, and reports of arrhythmia experts. Three authors independently reviewed and extracted the data regarding baseline characteristics, ablation methodology, medical therapy, complications, VT recurrences, mortality, and study quality. Results Five studies were included totaling 457 participants with structural heart disease. Adjunctive catheter ablation was performed in 58% of participants whereas 42% received medical therapy alone for VT. Complications of catheter ablation included death (1%), stroke (1%), cardiac perforation (1%), and complete heart block (1.6%). Using a random effects model, a statistically significant 35% reduction in the number of patients with VT recurrence was noted with adjunctive catheter ablation (P < 0.001). There was no statistically significant difference in mortality. Conclusion Catheter ablation as an adjunct to medical therapy reduces VT recurrences in patients with structural heart disease and has no impact on mortality. PMID:21147263
Chinushi, M; Aizawa, Y; Ohhira, K; Abe, A; Shibata, A
This study examined 12 VTs in 8 patients who underwent radiofrequency (RF) catheter ablation for ventricular tachycardia (VT) associated with non-ischemic underlying heart diseases, and who were followed-up for more than 24 months after ablation. The site of VT origin was determined to be within a narrow site (within 1.0 x 1.0 cm) in 5 VTs (4 patients), but VT originated from a wide origin (more than 1.0 x 1.0 cm) in the other 5 VTs (3 patients). The remaining patient had two macroreentrant VTs revolving around an anatomical obstacle in both the clockwise and counterclockwise directions. Two of 5 VTs originating from a narrow site were successfully ablated by 2-3 RF applications. In VT associated with a wide origin, two perpendicular linear RF lesions with 6.0 +/- 1.8 RF applications were required to ablate the VT. Eight of the 12 VTs (66.7%) were finally ablated by RF current (30-50 watts), and they did not recur during the follow-up period of 31.2 +/- 6.5 months. An excellent long-term outcome is expected, even in VT associated with non-ischemic underlying heart disease, if VT is successfully treated by RF ablation.
Wang, Yue Yi; Mesirca, Pietro; Marqués-Sulé, Elena; Villejoubert, Olivier; D’Ocon, Pilar; Ruiz, Cristina; Domingo, Diana; Zorio, Esther; Mangoni, Matteo E.; Benitah, Jean-Pierre; Gómez, Ana María
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal genetic arrhythmia that manifests syncope or sudden death in children and young adults under stress conditions. CPVT patients often present bradycardia and sino-atrial node (SAN) dysfunction. However, the mechanism remains unclear. We analyzed SAN function in two CPVT families and in a novel knock-in (KI) mouse model carrying the RyR2R420Q mutation. Humans and KI mice presented slower resting heart rate. Accordingly, the rate of spontaneous intracellular Ca2+ ([Ca2+]i) transients was slower in KI mouse SAN preparations than in WT, without any significant alteration in the “funny” current (If ). The L-type Ca2+ current was reduced in KI SAN cells in a [Ca2+]i-dependent way, suggesting that bradycardia was due to disrupted crosstalk between the “voltage” and “Ca2+” clock, and the mechanisms of pacemaking was induced by aberrant spontaneous RyR2- dependent Ca2+ release. This finding was consistent with a higher Ca2+ leak during diastolic periods produced by long-lasting Ca2+ sparks in KI SAN cells. Our results uncover a mechanism for the CPVT-causing RyR2 N-terminal mutation R420Q, and they highlight the fact that enhancing the Ca2+ clock may slow the heart rhythm by disturbing the coupling between Ca2+ and voltage clocks. PMID:28422759
Valle, Giorgia; Boncompagni, Simona; Sacchetto, Roberta; Protasi, Feliciano; Volpe, Pompeo
Cardiac calsequestrin (CASQ2) contributes to intracellular Ca(2+) homeostasis by virtue of its low-affinity/high-capacity Ca(2+) binding properties, maintains sarcoplasmic reticulum (SR) architecture and regulates excitation-contraction coupling, especially or exclusively upon β-adrenergic stimulation. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease associated with cardiac arrest in children or young adults. Recessive CPVT variants are due to mutations in the CASQ2 gene. Molecular and ultra-structural properties were studied in hearts of CASQ2(R33Q/R33Q) and of CASQ2(-/-) mice from post-natal day 2 to week 8. The drastic reduction of CASQ2-R33Q is an early developmental event and is accompanied by down-regulation of triadin and junctin, and morphological changes of jSR and of SR-transverse-tubule junctions. Although endoplasmic reticulum stress is activated, no signs of either apoptosis or autophagy are detected. The other model of recessive CPVT, the CASQ2(-/-) mouse, does not display the same adaptive pattern. Expression of CASQ2-R33Q influences molecular and ultra-structural heart development; post-natal, adaptive changes appear capable of ensuring until adulthood a new pathophysiological equilibrium. Copyright © 2014 Elsevier Inc. All rights reserved.
Bai, Jieyun; Wang, Kuanquan; Li, Qince; Yuan, Yongfeng; Zhang, Henggui
Mutations in the CACNA1C gene are associated with ventricular tachycardia (VT). Although the CACNA1C mutations were well identified in patients with cardiac arrhythmias, mechanisms by which cardiac arrhythmias are generated in such genetic mutation conditions remain unclear. In this study, we identified a novel mechanism of VT resulted from enhanced repolarization dispersion which is a key factor for arrhythmias in the CACNA1C G1911R mutation using multi-scale computational models of the human ventricle. The increased calcium influx in the mutation prolonged action potential duration (APD), produced steepened action potential duration restitution (APDR) curves as well as augmented membrane potential differences among different cell types during repolarization, increasing transmural dispersion of repolarization (DOR) and the spatial and temporal heterogeneity of cardiac electrical activities. Consequentially, the vulnerability to unidirectional conduction block in response to a premature stimulus increased at tissue level in the G1911R mutation. The increased functional repolarization dispersion anchored reentrant excitation waves in tissue and organ models, facilitating the initiation and maintenance of VT due to less meandering rotor tip. Thus, the increased repolarization dispersion caused by the G1911R mutation is a primary factor that may primarily contribute to the genesis of cardiac arrhythmias in Timothy Syndrome. PMID:27502440
Sasaki, Takeshi; Calkins, Hugh; Miller, Christopher F; Zviman, Menekhem M; Zipunnikov, Vadim; Arai, Tomio; Sawabe, Motoji; Terashima, Masashiro; Marine, Joseph E; Berger, Ronald D; Nazarian, Saman; Zimmerman, Stefan L
Myocardial fat deposition (FAT-DEP) has been frequently observed in regions of chronic myocardial infarction in patients with ischemic cardiomyopathy. The role of FAT-DEP within scar-related ventricular tachycardia (VT) circuits has not been investigated. This pilot study aimed to assess the impact of myocardial FAT-DEP on local electrograms and VT circuits in patients with ischemic cardiomyopathy. Contrast-enhanced computed tomography was performed in 22 patients with ischemic VT. Electroanatomic map points were registered to the corresponding contrast-enhanced computed tomography images. Myocardial FAT-DEP was identified and characterized using a postprocessing image overlay that highlighted areas below 0 Hounsfield units (HU). The mean attenuation of local myocardial regions corresponding to sampled electrograms was measured on short-axis images. The associations of mean attenuation with bipolar and unipolar amplitudes, left ventricular wall thickness, and VT circuit sites were investigated. Of 1801 electroanatomic map points, 519 (28.8%) were located in regions with FAT-DEP. Significant differences were observed in mean intensity (23.2 ± 35.6 HU vs 81.7 ± 21.9 HU; P < .001), bipolar (0.75 ± 0.83 mV vs 2.9 ± 2.4 mV; P < .001) and unipolar (3.1 ± 1.7 mV vs 7.4 ± 4.3 mV; P < .001) amplitudes, and left ventricular wall thickness (5.2 ± 1.7 mm vs 8.2 ± 2.5 mm; P < .001) between regions with and without FAT-DEP. Lower HU was strongly associated with lower bipolar and unipolar amplitudes (P < .0001, respectively). Importantly, FAT-DEP was associated with critical VT circuit sites with fractionated or isolated potentials. FAT-DEP was associated with electrogram characteristics and VT circuit sites. Further work will be needed to determine whether FAT-DEP plays a causal role in the generation of ischemic scar-related VT circuits. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Aizawa, Yoshifusa; Sato, Masahito; Kitazawa, Hitoshi; Aizawa, Yoshiyasu; Takatsuki, Seiji; Oda, Eiji; Okabe, Masaaki; Fukuda, Keiichi
J waves can be observed in individuals of the general population, but electrocardiographic characteristics are poorly understood. The purpose of this study was to examine the J-wave dynamicity in a general patient population. The responses of J waves (>0.1 mV above the isoelectric line in 2 contiguous leads) to varying RR intervals were analyzed. Patients with aborted sudden cardiac death, documented ventricular fibrillation, or a family history of sudden cardiac death were excluded. The J-wave amplitude was measured at baseline, in beats with short RR intervals in conducted atrial premature beats (APBs) or atrial stimulation during the electrophysiology study, and in the beats next to APBs with prolonged RR intervals. Mainly notched J waves were identified in 94 of 701 (24.5%) general patients (13.4%), and APBs were present in 23 of 94 (24.5%) patients. The mean baseline amplitude of J waves was 0.20 ± 0.06 mV at the baseline RR interval of 853 ± 152 ms, 0.25 ± 0.11 mV at the RR interval in the conducted APB of 545 ± 133 ms (P = .0018), and 0.19 ± 0.08 mV at the RR interval of 1146 ± 314 ms (P = .3102). The clinical characteristics were not different between patients with and without tachycardia-dependent augmentation of J waves. Augmentation of J waves was confirmed by the electrophysiology study: 0.28 ± 0.12 mV vs 0.42 ± 0.11 mV at baseline and in the beats of atrial stimulation, respectively (P = .0001). However, no bradycardia-dependent augmentation (>0.05 mV) was observed. Such tachycardia-dependent augmentation can represent depolarization abnormality rather than repolarization abnormality. J waves in a general patient population were augmented at shorter RR intervals, but not at prolonged RR intervals. Mechanistically, conduction delay is most likely responsible for this. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Maeno, M; Ishida, Y; Shimonagata, T; Hayashida, K; Toyama, T; Hirose, Y; Nagata, M; Miyatake, K; Uehara, T; Nishimura, T
123I-MIBG (MIBG) regional defects in myocardial regions with preserved 201Tl (Tl) uptake have been observed in patients with idiopathic dilated cardiomyopathy (DCM). To evaluate whether the presence of Tl/MIBG mismatched regions is related to the occurrence of ventricular tachycardia (VT), we performed myocardial dual SPECT imaging with Tl (111 MBq) and MIBG (111 MBq) in 17 patients with DCM, 11 (Gp A) with and 6 (Gp B) without VT. Myocardial dual SPECT imaging was performed at 15 minutes after and 4 hours after the tracer injection. The regional tracer uptake was scored visually in 6 segments of the basal, middle, and apical short-axial images and in 2 apical segments of the midventricular vertical long-axial image by a four-point scoring system (0 = normal, 1 = moderate, 2 = severe and 3 = complete defect). Then, the severity of tracer maldistributions was assessed by the difference between total defect scores (TDSs) of Tl and MIBG (delta TDS). TDS was not different between Gps A and B in both Tl and MIBG images. However, delta TDS was larger in Gp A than in Gp B (13.5 +/- 6.5 vs. 5.8 +/- 3.0, p < 0.05). Also, the number of segments with the mismatched tracer uptake was larger in Gp A than in Gp B (12.5 +/- 3.0 vs. 8.3 +/- 1.5, p < 0.01). In the electrophysiologic study, we found that the fractionated area corresponded to the mismatched region in 3 of 5 patients in Gp A. These results suggest that regional sympathetic denervation is a possible factor which provocates VT, and myocardial dual SPECT imaging with Tl and MIBG is a useful method for predicting VT in patients with DCM.
Bourke, Tara; Buch, Eric; Mathuria, Nilesh; Michowitz, Yoav; Yu, Ricky; Mandapati, Ravi; Shivkumar, Kalyanam; Tung, Roderick
There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT). Data were collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data were available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs. 76%, P = 0.002) and loss of capture (46% vs. 27%, P < 0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs. 71%, P = 0.02) and an EGM reduction (71% vs. 40%, P < 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed. VT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions, and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted. © 2014 Wiley Periodicals, Inc.
Bourke, Tara; Buch, Eric; Mathuria, Nilesh; Michowitz, Yoav; Yu, Ricky; Mandapati, Ravi; Shivkumar, Kalyanam; Tung, Roderick
Background There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT). Methods and Results Data was collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data was available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs 76%, p=0.002) and loss of capture (46% vs 27%, p<0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs 71%, p=0.02) and an EGM reduction (71% vs 40%, p< 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed. Conclusions VT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted. PMID:24946895
Freedom from recurrent ventricular tachycardia after catheter ablation is associated with improved survival in patients with structural heart disease: An International VT Ablation Center Collaborative Group study.
Tung, Roderick; Vaseghi, Marmar; Frankel, David S; Vergara, Pasquale; Di Biase, Luigi; Nagashima, Koichi; Yu, Ricky; Vangala, Sitaram; Tseng, Chi-Hong; Choi, Eue-Keun; Khurshid, Shaan; Patel, Mehul; Mathuria, Nilesh; Nakahara, Shiro; Tzou, Wendy S; Sauer, William H; Vakil, Kairav; Tedrow, Usha; Burkhardt, J David; Tholakanahalli, Venkatakrishna N; Saliaris, Anastasios; Dickfeld, Timm; Weiss, J Peter; Bunch, T Jared; Reddy, Madhu; Kanmanthareddy, Arun; Callans, David J; Lakkireddy, Dhanunjaya; Natale, Andrea; Marchlinski, Francis; Stevenson, William G; Della Bella, Paolo; Shivkumar, Kalyanam
The impact of catheter ablation of ventricular tachycardia (VT) on all-cause mortality remains unknown. The purpose of this study was to examine the association between VT recurrence after ablation and survival in patients with scar-related VT. Analysis of 2061 patients with structural heart disease referred for catheter ablation of scar-related VT from 12 international centers was performed. Data on clinical and procedural variables, VT recurrence, and mortality were analyzed. Kaplan-Meier analysis was used to estimate freedom from recurrent VT, transplant, and death. Cox proportional hazards frailty models were used to analyze the effect of risk factors on VT recurrence and mortality. One-year freedom from VT recurrence was 70% (72% in ischemic and 68% in nonischemic cardiomyopathy). Fifty-seven patients (3%) underwent cardiac transplantation, and 216 (10%) died during follow-up. At 1 year, the estimated rate of transplant and/or mortality was 15% (same for ischemic and nonischemic cardiomyopathy). Transplant-free survival was significantly higher in patients without VT recurrence than in those with recurrence (90% vs 71%, P<.001). In multivariable analysis, recurrence of VT after ablation showed the highest risk for transplant and/or mortality [hazard ratio 6.9 (95% CI 5.3-9.0), P<.001]. In patients with ejection fraction <30% and across all New York Heart Association functional classes, improved transplant-free survival was seen in those without VT recurrence. Catheter ablation of VT in patients with structural heart disease results in 70% freedom from VT recurrence, with an overall transplant and/or mortality rate of 15% at 1 year. Freedom from VT recurrence is associated with improved transplant-free survival, independent of heart failure severity. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Di Marco, Andrea; Paglino, Gabriele; Oloriz, Teresa; Maccabelli, Giuseppe; Baratto, Francesca; Vergara, Pasquale; Bisceglia, Caterina; Anguera, Ignasi; Sala, Simone; Sora, Nicoleta; Dallaglio, Paolo; Marzi, Alessandra; Trevisi, Nicola; Mazzone, Patrizio; Della Bella, Paolo
In patients with a prior myocardial infarction (MI), angiographic predictors of ventricular tachycardia (VT) recurrence after ablation are lacking. Recently, a proarrhythmic effect of a chronic total occlusion (CTO) in a coronary artery has been suggested. A total of 191 patients with prior MI were referred to our Hospital between 2010 and June 2013 for a first ablation of VT. Of these, 84 patients (44%) with stable coronary artery disease that underwent a coronary angiography during the index hospitalization were included in this study. A CTO in an infarct-related artery (IRA-CTO) was present in 47 patients (56%). Patients with and without IRA-CTO did not differ in terms of comorbidities, severity of heart failure, presentation of VT or acute outcome of ablation, that was completely successful in 93% of cases. At electroanatomic mapping, IRA-CTO was associated with greater scar and especially with greater area of border zone (34 cm(2) vs. 19 cm(2) , P = 0.001). Median follow-up was 19 months (IQR 18). At follow-up, patients with IRA-CTO had a significantly higher rate of VT recurrence (47% vs. 16%, P = 0.003). At multivariate analysis, IRA-CTO resulted to be an independent predictor of VT recurrence after ablation (HR 4.05, P = 0.004). IRA-CTO is an independent predictor of VT recurrence after ablation and identifies a subgroup of patients with high recurrence rate despite a successful procedure. IRA-CTO is associated with greater scars and border zone area; however, this association does not completely justify its proarrhythmic effect. © 2015 Wiley Periodicals, Inc.
Neco, Patricia; Torrente, Angelo; Mesirca, Pietro; Zorio, Esther; Liu, Nian; Priori, Silvia G.; Napolitano, Carlo; Richard, Sylvain; Benitah, Jean-Pierre; Mangoni, Matteo E.; Gómez, Ana María
Background Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is characterized by stress-triggered syncope and sudden death. CPVT patients manifest sino-atrial node (SAN) dysfunction, the mechanisms of which remain unexplored. Methods and Results We investigated SAN [Ca2+]i handling in mice carrying the CPVT-linked mutation of ryanodine receptor (RyR2R4496C) and on their wild-type (WT) littermates. In vivo telemetric recordings showed impaired SAN automaticity in RyR2R4496C mice following Isoproterenol (ISO) injection, analogous to what was observed in CPVT patients after exercise. Pacemaker activity was explored by measuring spontaneous [Ca2+]i transients in SAN cells within the intact SAN by confocal microscopy. RyR2R4496C SAN presented significantly slower pacemaker activity and impaired chronotropic response under β-adrenergic stimulation, accompanied by the appearance of pauses (in spontaneous [Ca2+]i transients and action potentials) in 75% of the cases. Ca2+ spark frequency was increased by 2-fold in RyR2R4496C SAN. Whole-cell patch-clamp experiments performed on isolated RyR2R4496C SAN cells showed that L-type Ca2+ current (ICa,L) density was reduced by ~50%, an effect blunted with internal Ca2+ buffering. ISO dramatically increased the frequency of Ca2+ sparks and waves by ~5 and ~10-fold, respectively. Interestingly, the sarcoplasmic reticulum (SR) Ca2+ content was significantly reduced in RyR2R4496C SAN cells in the presence of ISO, which may contribute to stopping the “Ca2+-clock” rhythm generation, originating SAN pauses. Conclusions The increased activity of RyR2R4496C in SAN leads to an unanticipated decrease on SAN automaticity by Ca2+-dependent decrease of ICa,L and SR Ca2+ depletion during diastole, identifying subcellular pathophysiologic alterations contributing to the SAN dysfunction in CPVT patients. PMID:22711277
Sasaki, Kenichi; Makiyama, Takeru; Yoshida, Yoshinori; Wuriyanghai, Yimin; Kamakura, Tsukasa; Nishiuchi, Suguru; Hayano, Mamoru; Harita, Takeshi; Yamamoto, Yuta; Kohjitani, Hirohiko; Hirose, Sayako; Chen, Jiarong; Kawamura, Mihoko; Ohno, Seiko; Itoh, Hideki; Takeuchi, Ayako; Matsuoka, Satoshi; Miura, Masaru; Sumitomo, Naokata; Horie, Minoru; Yamanaka, Shinya; Kimura, Takeshi
Introduction Human induced pluripotent stem cells (hiPSCs) offer a unique opportunity for disease modeling. However, it is not invariably successful to recapitulate the disease phenotype because of the immaturity of hiPSC-derived cardiomyocytes (hiPSC-CMs). The purpose of this study was to establish and analyze iPSC-based model of catecholaminergic polymorphic ventricular tachycardia (CPVT), which is characterized by adrenergically mediated lethal arrhythmias, more precisely using electrical pacing that could promote the development of new pharmacotherapies. Method and Results We generated hiPSCs from a 37-year-old CPVT patient and differentiated them into cardiomyocytes. Under spontaneous beating conditions, no significant difference was found in the timing irregularity of spontaneous Ca2+ transients between control- and CPVT-hiPSC-CMs. Using Ca2+ imaging at 1 Hz electrical field stimulation, isoproterenol induced an abnormal diastolic Ca2+ increase more frequently in CPVT- than in control-hiPSC-CMs (control 12% vs. CPVT 43%, p<0.05). Action potential recordings of spontaneous beating hiPSC-CMs revealed no significant difference in the frequency of delayed afterdepolarizations (DADs) between control and CPVT cells. After isoproterenol application with pacing at 1 Hz, 87.5% of CPVT-hiPSC-CMs developed DADs, compared to 30% of control-hiPSC-CMs (p<0.05). Pre-incubation with 10 μM S107, which stabilizes the closed state of the ryanodine receptor 2, significantly decreased the percentage of CPVT-hiPSC-CMs presenting DADs to 25% (p<0.05). Conclusions We recapitulated the electrophysiological features of CPVT-derived hiPSC-CMs using electrical pacing. The development of DADs in the presence of isoproterenol was significantly suppressed by S107. Our model provides a promising platform to study disease mechanisms and screen drugs. PMID:27764147
Jin, Qi; Jacobsen, Peter Karl; Pehrson, Steen; Chen, Xu
Ventricular tachycardia (VT) recurrence after catheter ablation for electrical storm is commonly seen in patients with ischemic cardiomyopathy (ICM). We hypothesized that VT recurrence can be predicted and be related to the all-cause death after VT storm ablation guided by remote magnetic navigation (RMN) in patients with ICM. A total of 54 ICM patients (87% male; mean age, 65 ± 7.1 years) presenting with VT storm undergoing acute ablation using RMN were enrolled. Acute complete ablation success was defined as noninducibility of any sustained monomorphic VT at the end of the procedure. Early VT recurrence was defined as the occurrence of sustained VT within 1 month after the first ablation. After a mean follow-up of 17.1 months, 27 patients (50%) had freedom from VT recurrence. Sustained VT recurred in 12 patients (22%) within 1 month following the first ablation. In univariate analysis, VT recurrence was associated with incomplete procedural success (hazard ratio [HR]: 6.25, 95% confidence interval [CI]: 1.20-32.47, P = 0.029), lack of amiodarone usage before ablation (HR: 4.71, 95% CI: 1.12-19.7, P = 0.034), and a longer procedural time (HR: 1.023, 95% CI: 1.00-1.05, P = 0.05). The mortality of patients with early VT recurrence was higher than that of patients without recurrence (P < 0.01). Inducibility of any VT at the end of procedure for VT storm guided by RMN is the strongest predictor of VT recurrence. ICM patients who have early recurrences after VT storm ablation are at high risk of all-cause death. © 2017 Wiley Periodicals, Inc.
Acosta, Juan; Fernández-Armenta, Juan; Penela, Diego; Andreu, David; Borras, Roger; Vassanelli, Francesca; Korshunov, Viatcheslav; Perea, Rosario J; de Caralt, Teresa M; Ortiz, Jose T; Fita, Guillermina; Sitges, Marta; Brugada, Josep; Mont, Lluis; Berruezo, Antonio
There is no consensus on the appropriate indications for the epicardial approach in substrate ablation of post-myocardial infarction (MI) ventricular tachycardia (VT). The purpose of this study was to investigate whether infarct transmurality (IT) could identify patients who would benefit from a combined first-line endo-epicardial approach. Before ablation, IT was assessed by contrast-enhanced cardiac magnetic resonance imaging (hyperenhancement ≥75% of the wall thickness in ≥1 segment), echocardiography (dyskinesia/akinesia + hyperrefringency + wall thinning), computed tomography (wall thinning), or scintigraphy (transmural necrosis). Prospectively from January 2011, an endocardial approach was used in patients with subendocardial MI (group 1) and a combined endo-epicardial approach in patients with transmural MI (group 2). Outcomes in both groups were compared with those in patients with transmural MI and only endocardial approach due to previous cardiac surgery or procedure performed before January 2011 (group 3). The primary end point was VT/ventricular fibrillation recurrence-free survival. Ninety patients (92.2% men; mean age 67.4 ± 9.8 years) undergoing VT substrate ablation were included: group 1, n = 34; group 2, n = 24; group 3, n = 32. During a mean follow-up duration of 22.5 ± 13.7 months, 5 patients in group 1 (14.7%), 3 patients in group 2 (12.5%), and 13 patients in group 3 (40.6%) had VT recurrences (P = .011). Time to recurrence was the shortest in group 3 (log-rank, P = .018). The endocardial approach in patients with transmural MI was associated with an increased risk of recurrence (hazard ratio 4.01; 95% confidence interval 1.41-11.3; P = .009). The endocardial approach in patients with transmural MI undergoing VT substrate ablation is associated with an increased risk of recurrence. IT may be a useful criterion for the selection of a first-line combined endo-epicardial approach. Copyright © 2016 Heart Rhythm Society. Published by
Patel, Divyang; Hasselblad, Vic; Jackson, Kevin P; Pokorney, Sean D; Daubert, James P; Al-Khatib, Sana M
Patients with ischemic heart disease may have implantable cardioverter defibrillators (ICDs) implanted for primary or secondary prevention of sudden cardiac death. Although ICD shocks can be life saving, in some patients, they have been associated with increased mortality and/or morbidity. Several studies have suggested that catheter ablation may be superior to non-ablative strategies at preventing ICD shocks delivered for ventricular arrhythmias; however, this is still controversial. We performed a meta-analysis of randomized controlled trials (RCTs) comparing catheter ablation with non-ablative strategies in treatment of ventricular tachycardia (VT) in patients with ischemic heart disease and an ICD. The primary endpoints of interest were recurrent episodes of VT and death. We used a binary random effects method to calculate the cumulative odds ratios (OR) for recurrent VT and deaths. Of a total of 643 potential citations, our search yielded three citations that met our inclusion and exclusion criteria. In the three trials, a total of 262 patients were randomized to ablation (n = 129) or non-ablative interventions (beta-blockers ± use of antiarrhythmics) (n = 133) group. The cumulative OR for recurrent VT was 0.471 (95% confidence interval (CI) = 0.176-1.257) for catheter ablation compared with non-ablative strategies, and for death, it was 0.766 (95% CI = 0.351-1.674). Excluding one study for being appreciably smaller than the other two, the OR for recurrent VT was 0.298 (95% CI = 0.164-0.543). In this meta-analysis, the rate of recurrent VT was lower with VT catheter ablation compared with non-ablative strategies. There was not a significant difference in rate of death among patients receiving catheter ablation versus non-ablative strategies for management of VT. Given the lack of adequately powered RCTs comparing ablation versus medical management of VT in patients with ischemic heart disease and an ICD, larger studies with longer
Sasaki, Takeshi; Calkins, Hugh; Miller, Christopher F.; Zviman, Menekhem M.; Zipunnikov, Vadim; Arai, Tomio; Sawabe, Motoji; Terashima, Masashiro; Marine, Joseph E.; Berger, Ronald D.; Nazarian, Saman; Zimmerman, Stefan L.
Background Myocardial fat deposition (FAT-DEP) has been frequently observed in regions of chronic myocardial infarction in patients with ischemic cardiomyopathy (ICM). The role of FAT-DEP within scar-related ventricular tachycardia (VT) circuits has not been investigated. Objective This pilot study aimed to assess the impact of myocardial FAT-DEP on local electrograms and VT circuits in patients with ICM. Methods Contrast-enhanced computed tomography (CE-CT) was performed in 22 patients with ischemic VT. Electroanatomic map (EAM) points were registered to corresponding CE-CT images. Myocardial FAT-DEP were identified and characterized using a post-processing image overlay that highlighted areas below 0 Hounsfield units (HU). The mean attenuation of local myocardial regions corresponding to sampled electrograms was measured on short axis images. The associations of mean attenuation with bipolar and unipolar amplitudes, left ventricular (LV) wall thickness and VT circuit sites were investigated. Results Of 1801 EAM points, 519 (28.8%) were located in regions with FAT-DEP. Significant differences were observed in mean intensity (23.2±35.6 vs. 81.7±21.9 HU, P<0.001), bipolar (0.75±0.83 vs 2.9±2.4 mV, P<0.001) and unipolar (3.1±1.7 vs. 7.4±4.3 mV, P<0.001) amplitudes and LV wall thickness (5.2±1.7 vs. 8.2±2.5 mm, P<0.001) between regions with and without FAT-DEP. Lower HU was strongly associated with lower bipolar and unipolar amplitude (P<0.0001, respectively). Importantly, FAT-DEP was associated with critical VT circuit sites with fractionated or isolated potentials. Conclusions FAT-DEP was associated with electrogram features and VT circuit sites. Further work will be needed to determine whether FAT-DEP plays a causal role in the generation of ischemic scar-related VT circuits. PMID:25814415
Acosta, Juan; Cabanelas, Nuno; Penela, Diego; Fernández-Armenta, Juan; Andreu, David; Borràs, Roger; Korshunov, Viatcheslav; Cabrera, Mario; Vasanelli, Francesca; Arbelo, Elena; Guasch, Eduard; Martínez, Mikel; Tolosana, Jose M; Mont, Lluis; Berruezo, Antonio
This study assessed the benefit of peri-implantable cardioverter-defibrillator implant ventricular tachycardia (VT)-substrate ablation in patients with structural heart disease (SHD). Patients with SHD and indication for secondary prevention ICD implant were prospectively included. Patients presenting with incessant and/or slow VT or frequent (≥2) VT episodes who underwent peri-ICD VT-substrate ablation (the scar dechannelling technique) were compared with those who received ICD alone and did not meet ablation criteria. The primary endpoint was any sustained VT/ICD therapy during follow-up. Of 206 patients included (43.2% non-ischaemic), 70 were assigned to ablation and 136 received ICD implant alone. During a mean follow-up of 45.6 ± 24.7 months, the primary endpoint was more frequent in the non-ablation group (47.1 vs. 22.9%; P< 0.0001). Higher VT recurrence-free survival rate [log-rank P= 0.001; HR = 0.42 (0.24-0.73), P= 0.002] and ICD shock-free survival rate [log-rank P= 0.007; HR = 0.36 (0.17-0.78); P = 0.01] were observed in the ablation group. Higher relative risk reduction was observed in ischaemic [HR = 0.38 (0.18-0.83); P = 0.015] vs. non-ischaemic patients [HR = 0.49 (0.23-1.01); P = 0.08]. Patients with left ventricular ejection fraction (LVEF) <35% showed no differences in VT recurrence between treatment groups (log-rank P = 0.213) although VT burden during follow-up was lower in the ablation group [median (interquartile range) 1 (1-3) vs. 4 (1-10) VT episodes; P = 0.05]. First-line peri-ICD implant VT-substrate ablation was associated with decreased VT recurrence and ICD shocks during long-term follow-up in patients with SHD and indication for secondary prevention ICD implant, especially in ischaemic patients. In patients with LVEF <35%, no benefit was observed in terms of VT recurrence-free survival, although VT burden during follow-up was lower in the ablation group.
The evaluation of a nonsustained wide QRS tachycardia in a life insurance applicant's exercise test presents a special challenge to the medical director because of the unpredictable and potentially lethal nature of these arrhythmias. Ventricular tachycardia accounts for up to 80% of wide QRS tachycardias in unselected populations and more than 95% of cases with a prior myocardial infarction. Malignant ventricular arrhythmias usually occur in the presence of significant structural heart disease. In this setting, ventricular arrhythmias carry a high risk of sudden cardiac death. Less commonly, ventricular tachycardia occurs in hearts that appear normal. In many such cases, however, the heart is in fact not normal, but rather has less visible abnormalities including derangements of cardiac ion channels or structural proteins. In these individuals, ventricular arrhythmias also carry a high risk of sudden cardiac death. There are, however, some ventricular tachycardia syndromes which occur in normal hearts that have a more benign prognosis.
Mendoza, I J; Castellanos, A; Sung, R J
A patient with Wolff-Parkinson-White syndrome type B developed 2:1 atrioventricular block resulting from the association of persistent right bundle-branch block with tachycardia-dependent (phase 3) left bundle-branch block. Electrophysiological studies disclosed the coexistence of a tachycardia-dependent (phase 3) block in the accessory pathway. This conduction disturbance was exposed, not by carotid sinus massage as in previous studies, but by pacing-induced prolongation of the interval between two consecutively conducted atrial impulses. Furthermore, the surface electrocardiogram showed, at different times, ventricular complexes resulting from: (1) exclusive atrioventricular conduction through the normal pathway without bundle-branch block; (2) predominant, or exclusive, atrioventricular conduction through a right-sided accessory pathway; (3) exclusive atrioventricular conduction through the normal pathway with right bundle-branch block; (4) exclusive conduction through the normal pathway, with left bundle-branch block; (5) fusion between (1) and (2); and finally, (6) fusion between (2) and (3) However, QRS complexes resulting from simultaneously occurring Wolff-Parkinson-White syndrome type B and left bundle-branch block could not be identified. Future electrophysiological investigations should re-evaluate the criteria used to diffrentiate between true and false patterns of Wolff-Parkinson-White syndrome type B coexisting with left bundle-branch block. PMID:7397051