New-Onset Ventricular Tachycardia After Cardiac Resynchronization Therapy

It is well established that coronary artery disease with healed myocardial infarction is the most common backdrop for ventricular tachycardia (VT). Although the clinical benefits of biventricular pacing (BivP) in the treatment of severe heart failure are well documented, exact relation with ventricular arrhythmias remains still unclear.We describe a case of a patient, whitout a previous history of arrhythmic episodes, in which the onset of several episodes of VT presented immediatly after cardiac resynchronization therapy (CRT) and did not occur after BivP discontinuation.     

Idiopathic Ventricular Tachycardia and Fibrillation

Idiopathic Ventricular Tachycardia and Fibrillation. Important data have recently been added to our understanding of sustained ventricular tachyarrhythmias occurring in the absence of demonstrable heart disease. Idiopathic ventricular tachycardia (VT) is usually of monomorphic configuration and can be classified according to its site of origin as either right monomorphic (70% of all idiopathic VTs) or left monomorphic VT. Several physiopathological types of monomorphic VT can be presently individualized, according to their mode of presentation, their relationship to adrenergic stress, or their response to various drugs. The long-term prognosis is usually good. Idiopathic polymorphic VT is a much rarer type of arrhythmia with a less favorable prognosis. Idiopathic ventricular fibrillation may represent an underestimated cause of sudden cardiac death in ostensibly healthy patients. A high incidence of inducibility of sustained polymorphic VT with programmed ventricular stimulation has been found by our group, but not by others. Long-term prognosis on Class IA antiarrhythmic medications that are highly effective at electrophysiologic study appears excellentJfy Cardiovasc Electrophysiol, Vol. 4, pp. 356–368, June 1993 ).     

Spontaneous Variability of Ventricular Ectopic Activity in Patients with Sustained Ventricular Tachycardia and in Survivors of Cardiac Arrest

Background: Spontaneous variability of ventricular arrhythmia has been described in patients with chronic stable ventricular arrhythmias and in patients with chronic heart failure. However, no data are available on spontaneous variability in patients with sustained ventricular tachyarrhythmias. Thus, the present study was designed to prospectively determine the extent of spontaneous variability of ventricular arrhythmia in patients with sustained ventricular tachyarrhythmias and in survivors of cardiac arrest. Methods: Ventricular arrhythmia variability was determined in 470 patients (413 men, 57 women), age (mean ± SD) 64.6 ± 9.5 years with documented ventricular tachycardia (VT), cardiac arrest, or syncope who were prospectively enrolled in a randomized trial of the comparison of electrophysiological testing with Holter monitoring to predict antiarrhythmic drug efficacy. Coronary artery disease was present in 398 (85%) patients, and the mean left ventricular ejection fraction was 0.32 ± 0.13. They underwent two 24-hour ambulatory recordings separated by 1 day. Spontaneous variability was determined for total premature ventricular complexes (PVCs), pairs, and VT events. Results: Arithmetic mean of hourly total PVCs on day 1 was 315 ± 425. The 95% confidence limit of spontaneous reduction in total PVC count was 71%. Corresponding values for pairs, VT events of 3–15 beats, < 15 beats, or < 15 seconds were 72%, 80%, 94%, and 95%, respectively. The percentage increases in total PVCs, pairs, and VT events 3–15 beats, < 15 beats, and < 15 seconds were 243%, 259%, 397%, 1553%, and 1756%, respectively. The percentage reduction required to show a true drug effect was 63% for patients with an ejection fraction > 0.32 and 76% for those with an ejection fraction ltm 0.32 (P = 0.024). Patients who presented with unmonitored syncope showed less spontaneous variability than either patients with documented, sustained VT or cardiac arrest. Conclusions: Marked spontaneous variability of ventricular arrhythmias is observed in patients with sustained ventricular tachyarrhythmias. Variability is affected by the degree of left ventricular dysfunction. The lowest variability was observed in patients presenting with unmonitored syncope. Thus, large changes in arrhythmia frequency must be observed in this population, as in others, to be ascribed to drug effect.     

The Prognostic Significance of Inducing Nonsustained Ventricular Tachycardia in Patients Presenting with Sustained Ventricular Tachycardia or Cardiac Arrest

The significance of inducing nonsustained ventricular tachycardia during baseline electrophysiological testing in patients presenting with sustained ventricular arrhythmias is unclear. In this study, 145 consecutive patients presenting with cardiac arrest or sustained ventricular tachycardia underwent electrophysiological study. Twenty five (17%) had no inducible ventricular tachycardia (group I), 33 (23%) had inducible nonsustained ventricular tachycardia (group II), and 87 (60%) had inducible sustained ventricular tachycardia (group 111). Group I was not treated with antiarrhythmic therapy. Groups II and III underwent serial drug trials guided by electrophysiological testing. Mean follow-up for all three groups was 31 ± 18 months. The actuarial rate of arrhythmia recurrence for group 1 at 12, 24, and 36 months of follow-up was 0%, 6%, and 17%, respectively. This actuarial arrhythmia recurrence rate for group I was significantly lower (P < 0.05) than that of group II (16%, 27%, and 32%) and group III (32%, 39%, and 44%). There was no significant difference between the arrhythmia recurrence rates in groups 11 and III. When groups II and III were broken down into drug responders and nonresponders, drug responders in both groups had significantly fewer arrhythmia recurrences than nonresponders (P < 0.05). The overall incidence of sudden death was low (11 of 145, 8%) and not significantly different between groups I, II, and III. In summary, among patients who present with sustained ventricular arrhythmias, those who have nonsustained ventricular tachycardia induced during baseline electrophysiological testing respond to serial drug testing and have long-term outcomes similar to those with inducible sustained ventricular tachycardia.     

Imaging in Cardiac Echinococcosis

Cardiac echinococcosis is a rare disease. Its diagnosis is sometimes difficult and requires medical imaging such as echocardiography. An 18-year-old man with multiple cardiac hydatid cysts diagnosed by echocardiography and nuclear magnetic resonance is presented. The results from these imaging techniques are presented.     

Nonsurgical Transthoracic Epicardial Approach in Patients with Ventricular Tachycardia and Previous Cardiac Surgery

INTRODUCTION: The subxyphoid pericardial mapping approach can be used to facilitate catheter ablation of postmyocardial-infarction ventricular tachycardia (post-MI VT), but the presence of dense adhesions is thought to preclude this approach in patients who have previously undergone open-chest cardiac surgery. AIMS OF THE STUDY: This study reports the first use of a nonsurgical transthoracic epicardial approach in patients with scar-related VT and previous cardiac surgery. METHODS: Five patients with a mean age of 67 +/- 10 years, left ventricular ejection fraction (LVEF) of 40 +/- 4.3%) and recurrent VT occurring 7 months to 10 years after cardiac surgery underwent combined endocardial and epicardial mapping and ablation during the same session. Because pericardial adhesions were anticipated to be denser in the anterior wall, the nonsurgical transthoracic epicardial puncture was directed to the inferior wall of the left ventricle. Failure to interrupt VT with radio frequency (RF) energy pulses delivered at the best endocardial or epicardial site prompted changing from one approach to the other. RESULTS: During the epicardial puncture procedure, the contrast medium accumulated in the inferior wall instead of spreading around the cardiac silhouette. The pericardial sac could be entered in all patients, and mapping of the inferolateral epicardial wall of the left ventricle was feasible. Fourteen VTs were induced, of which 8 could not be mapped because of poor hemodynamic tolerance. Three of the remaining 6 mappable VTs were eliminated by endocardial ablation, 2 required an epicardial RF pulse to be rendered noninducible, and 1 VT was not eliminated. No intra- or postprocedural complications were noted despite full heparinization. CONCLUSION: Nonsurgical transthoracic epicardial catheter mapping and ablation of epicardial VT related to the inferolateral left ventricular wall are feasible in patients who have previously undergone open- cardiac surgery.     

Ventricular Tachycardia/Ventricular Fibrillation Ablation in the Setting of Ischemic Heart Disease

Recurrent ventricular tachycardia (VT) in the setting of coronary artery disease is frequently a life-threatening electrophysiologic emergency. Even in patients with an implantable defibrillator, recurrent VT is frequently accompanied by repeated and disabling shock therapy. Catheter ablative therapy offers the ability to provide immediate control of recurrent VT. Long-term elimination of VT should be anticipated in most patients. This article reviews the strategies, tools, techniques, and expected outcome for catheter ablation of stable and unstable ventricular arrhythmias in the setting ischemic heart disease.     

Ventricular Tachycardia

Congenitally Corrected Transposition and VT. Ventricular tachycardia (VT) is an uncommon finding in patients with congenitally corrected transposition of the great arteries (CCTGA). Cardiac death in patients with CCTGA has been attributed to complete heart block, systemic ventricular dysfunction, or severe AV valve regurgitation with heart failure. We descrihe the case of a patient who presented with palpitations and near-syncope that was associated with clinical episodes of VT. Programmed ventricular stimulation revealed easily inducible sustained VT that immediately degenerated to ventricular fibrillation and subsequently required therapy with an implantable cardioverter defibrillator.     

Relationship Between Ventricular Rate Variability in Nonsustained Ventricular Tachycardia and Subsequent Cardiac Events

Background: Clinical and experimental observations indicate that reduced beat-to-beat changes in the cycle length of nonsustained ventricular tachycardia (NSVT) may portend malignant ventricular tachyarrhythmias and sudden cardiac death. The purpose of the study was to test the hypothesis that measures of ventricular rate variability during NSVT (VRV-NSVT) may be useful in identifying patients at high risk of life-threatening arrhythmic events. Methods: The study group consisted of 326 patients who had NSVT on 24-hour ECG recordings. Temporal changes in up to 10 beat-to-beat intervals of NSVT runs (V-V) were assessed. The following parameters of VRV-NSVT were calculated: (1) average value of successive differences in V-V intervals (ADVV); and (2) normalized average value of successive differences in V-V intervals (nADVV). Results: During a mean follow-up of 4 years, 52 (16%) patients had a documented episode of sustained VT or ventricular fibrillation. Patients with these arrhythmic events had significantly (P < 0.001) lower values of ADVV and nADVV variables in comparison to patients without arrhythmic events. The relative risk of malignant arrhythmic events for patients with ADW < 40 ms was 4.9 (P < 0.001), for patients with nADVV < 6%, the risk was 3.9 (P < 0.001). Conclusions: The results of this study indicate a strong and significant relationship between NSVT and the risk of subsequent malignant ventricular tachycardia. The assessment of VRV-NSVT may be useful for identifying patients at high and low risk for subsequent arrhythmic events.     

Surgery for Ventricular Tachycardia

The treatment of drug-refractory chronic ventricular tachycardia (VT) has undergone a revolution over the last 50 years. We now have automatic implantable cardioverter defibrillator therapy with pace-terminating capabilities, and catheter ablation of VT has refined mapping and improved methods of lesion generation. Between 1980 and 1993, Houston Methodist Hospital became a leader in the diagnosis and surgical ablation of VT and other arrhythmias. This is a brief account of that period and some of the experiences and lessons that have led to significant advances used today.     

The Duration of Induced Ventricular Tachycardia as Related to Clinically Sustained Ventricular Tachycardia

Programmed electrical stimulation has been extremely useful in the management of patients with sustained ventricular tachycardia or cardiac arrest. However, the definition of sustained ventricular tachycardia is controversial, and the relationship between the duration of induced ventricular tachycardia and the risk for spontaneous ventricular tachycardia has not been adequately defined. Thus, we examined the records of 64 patients with at least three beats of induced ventricular tachycardia during EP studies using single and double premature stimuli in sinus rhythm and during ventricular paced rhythm (two sites, up to three drive cycle lengths) and using ventricular burst pacing to correlate maximum length of induced ventricular tachycardia with the nature of their spontaneous arrhythmias. Forty-nine patients (77%) had ventricular tachycardia requiring intervention to terminate it, which we called sustained. Nine patients (14%) had ten or fewer beats of ventricular tachycardia; four patients (6%) had 11 to 20 beats of ventricular tachycardia; and two patients (3%) had more than 20 beats of ventricular tachycardia which did not require intervention for termination. Inducible sustained ventricular tachycardia had a sensitivity of 88% and a specificity of 92% for identifying patients with clinical sustained ventricular tachycardia or fibrillation. More than 20 beats of inducible ventricular tachycardia had a sensitivity of 92% and a specificity of 92%. More than 10 beats of inducible ventricular tachycardia achieved a sensitivity of 98% and a specificity of 91% for identifying patients with sustained ventricular tachycardia or fibrillation. The criteria used for the duration of inducible ventricular tachycardia are arbitrary and the interpretation of inducible nonsustained ventricular tachycardia must depend on the purpose of the test and the prior probability of each result.     

Sustained Ventricular Tachycardia as the First Manifestation of Hydatid Cyst Located in the Interventricular Septum

Echinococcus granulosus infection may manifest with cardiac involvement causing various symptoms. Here, we discuss a case of a young patient who presented with sustained ventricular tachycardia (VT) causing hemodynamic compromise. Diagnosis of cardiac hydatid cyst was established with echocardiography, computed tomography imaging, and serological examination. After surgical removal of the cyst VT did not recur.     

Long-Term Results of Visually Guided Left Ventricular Reconstruction as Single Therapy to Treat Ventricular Tachycardia Associated with Postinfarction Anteroseptal Aneurysm

Visually Guided Left Ventricular Reconstruction for Recurrent VT. Introduction: Postinfarction ventricular tachycardia (VT), anteroseptal aneurysm. and ventricular dysfunction are commonly associated and predict a poor long-term prognosis. Surgical left ventricular reconstruction, which includes double plication of the anterior and septal wall, can improve ventricular function. This article analyzes the long-term efficacy of such a procedure to control recurrence of VT in a group of 50 consecutive patients.
Methods and Results: The study group consisted of 50 consecutive patients operated on between December 1986 and December 1994. The group comprised 44 men and 6 women. The mean age was 56 ± 11 years. All patients had spontaneous VT following an anterior myocardial infarction. Twenty-five patients had two or more episodes of VT (eight presented as cardiac arrest, nine as syncope). Coronary artery disease was limited to the left anterior descending artery in 27 patients. An anteroseptal aneurysm was present in 49 patients. All patients had VT induced by programmed ventricular stimulation before surgery, and left ventricular reconstruction was performed without intraoperative mapping in all cases. Total mortality, VT recurrence, and sudden death rate were the endpoints of the study. In-hospital mortality was 8%. Postoperative left ventricular ejection fraction improved from 0.38 to 0.50 ( P < 0.05). Only two patients had postoperative inducible VT. Overall survival, VT recurrence rate, and sudden death rate were 73%, 12%, and 10%, respectively, after a median follow-up period of 6.25 years (0 to 8 years).
Conclusion: Visually guided left ventricular reconstruction with septal and anterior wall plicature can he utilized effectively to treat recurrent VT associated with postinfarction anteroseptal aneurysm.