Profile of patients presenting with sustained ventricular tachycardia in a tertiary care center

Background and aimVentricular tachycardia (VT) represents the most frequent cause of sudden cardiac death. Information on clinical characteristics, acute management and outcome of patients with sustained VT is limited in our part of world. The aim of this study was to analyze the demography, hemodynamics, ECG features, underlying disease, mode of termination and outcome of patients presenting with VT.MethodsThis single center cohort study represents total of 107 patients of VT enrolled over 45 months.ResultsMean age was 45 years and 59 of the patients were males. Thirty three of these patients were hemodynamically unstable (31%) and 74 were stable (69%) Coronary artery disease was the most common etiological factor accounting for 39% of patients followed by non-ischemic cardiomyopathy. Determinants of hemodynamic instability were VT in course of acute myocardial infarction (8 out of fourteen) and polymorphic pattern of VT (13 out of 26). Spontaneous termination of VT occurred in seven patients, antiarrythmic drugs terminated VT in 53 of 67 patients and in remaining 45 patients VT was terminated with direct current (DC) cardioversion. Total of twenty three patients died during the hospital stay. Factors that contributed to mortality were old age, hemodynamic instability and low ejection fraction.ConclusionIschemic heart disease remains the leading cause of VT. Hemodynamically unstable VT occurs more frequently in acute myocardial infarction and polymorphic VT. Most effective method of VT termination is DC cardioversion. Old age, hemodynamic instability and ejection fraction contribute to overall mortality in VT.     

Development of a depressed left ventricular ejection fraction in patients with left ventricular hypertrophy and a normal ejection fraction

The progression from concentric left ventricular (LV) hypertrophy to heart failure has not been well defined. Of 159 predominantly hypertensive African-American patients with LV hypertrophy and a normal ejection fraction (EF), 28 (18%) developed a reduced EF after a median follow-up of approximately 4 years. Risk factors for this outcome included a history of coronary artery disease, pulmonary edema seen on a chest x-ray, or a subsequent myocardial infarction.     

Filtered QRS duration on signal-averaged electrocardiography correlates with ventricular dyssynchrony assessed by tissue Doppler imaging in patients with reduced ventricular ejection fraction

Objectives

The relationships between filtered QRS duration and ventricular dyssynchrony were studied.

Methods

We measured filtered QRS duration on signal-averaged electrocardiography and analyzed tissue Doppler imaging in chronic heart failure patients with ejection fraction less than 50%.

Results

In 64 patients, interventricular and intraventricular dyssynchronies were observed in 25 and 38 patients, respectively. All patients with interventricular dyssynchrony were associated with intraventricular dyssynchrony. Filtered QRS showed 0.82 and 0.78 of the area under the curve (AUC) in the receiver operating characteristic curve (ROC) for the detection of interventricular and intraventricular dyssynchrony, respectively, with 89.7% and 96.2% specificity and 52.0% and 52.6% sensitivity, with cutoff values of 174 and 153 milliseconds. Specificity and sensitivity as well as AUC were lower in the ROC of QRS duration than filtered QRS duration.

Conclusion

Filtered QRS duration provided more reliable information to estimate ventricular dyssynchrony in patients with reduced ventricular ejection fraction than QRS duration did.     

Naxos disease presenting with ventricular tachycardia and troponin elevation

Naxos disease is a recessively inherited stereotype association of arrhythmogenic cardiomyopathy with a cutaneous phenotype, characterized by peculiar woolly hair and palmoplantar keratoderma. The cardiomyopathy clinically manifests by adolescence and the symptomatic presentation is usually with syncope and/or sustained ventricular tachycardia of left bundle branch block configuration. We report the case of a 43-year-old man without any history of heart disease who was admitted to the hospital because of an episode of sustained ventricular tachycardia and troponin I elevation, in the absence of coronary artery disease. Diagnostic workup, including genetic assessment, revealed Naxos disease as the underlying cause. In this case, acute myocarditis seems to be the most plausible explanation for the nonischemic myocardial injury.     

Isolated left ventricular non-compaction in association with ventricular tachycardia

A 32-year-old young male was found to have non-sustained, repetitive, monomorphic ventricular tachycardia of right bundle branch morphology during routine pre-anaesthetic evaluation for orthopaedic surgery. Echocardiography and left ventricular angiogram were suggestive of isolated non-compaction of left ventricular apex with systolic dysfunction. He was successfully managed with anti-arrhythmic drugs and had an uneventful 9-month follow-up. The index case is an unusual association of asymptomatic, non-sustained ventricular tachycardia with isolated ventricular non-compaction.     

Sinus rhythm QRS amplitude and fractionation in patients with nonischemic cardiomyopathy to identify ventricular tachycardia substrate and location

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室性心动过速患者QT离散度变化的临床意义

目的　探讨室性心动过速 (VT)患者 QT离散度 (QTd)变化的意义。方法　对正常对照组 (35例 )和 VT组 (31例 )记录 12导联同步心电图 ,人工测量 QT间期 ,计算 QTd。结果　与对照组相比 ,VT组 12导联QTd明显增加 (P<0 .0 1) ,但两组之间存在很大交叉 ,无法建立正常参考值 ;QT间期明显延长 (P<0 .0 1) ,两组QTmax多见于 V2 、V3、V4 和 V5导联 (分别为 75 .0 %、77.8% ) ,两组 QTmax、QTmin导联分布无显著差异 (P>0 .0 5 )。结论　 VT患者的 QTd不能代表心肌复极的区域性差异 ,仅可作为心肌复极异常简单、粗略的指标。     

Long-term antiarrhythmic efficacy and safety of d-sotalol in patients with ventricular tachycardia and a low ejection fraction

Summary Since in patients with ventricular tachycardia (VT) and compromised left ventricular function, antiarrhythmic therapy poses a particular problem, an open-label safety study of d-sotalol, a new class III antiarrhythmic agent, was performed. Thirteen patients with defined VT and a low left ventricular ejection fraction (LVEF) were treated with orally administered d-sotalol, 100 mg bid, and in a few patients 100 mg tid, in an open study. Patients were followed up for 35±11 months, with the longest follow-up amounting to 51 months. The data obtained suggest that d-sotalol was moderately effective as an antiarrhythmic agent, in particular with respect to premature ventricular contractions (PVCs) and coupled and repetitive PVCs. The beneficial effect appeared to persist on long-term treatment. d-Sotalol was well tolerated and no subjective or objective adverse reactions were observed. There were no signs of worsening of congestive heart failure, proarrhythmogenic activity, or torsades de pointes, although QT-prolongation was observed. There were no dropouts in the study. Two patients died: One patient with idiopathic dilated cardiomyopathy (with LVEF=11%) died suddenly after 38 months of follow-up and one patient after 17 months from recurrent myocardial infarction. Neither of these had shown recurrence of VT on 24 hour ambulatory ECG recordings. In conclusion, in this small group of patients d-sotalol appeared to be safe and well tolerated during long-term treatment of patients with VT and poor left ventricular function. There were clear suggestions of antiarrhythmic activity, reflected by the suppression of complex ventricular arrhythmias and by the absence of recurrent VT on long-term follow-up in the majority of patients. These results would encourage a larger, formal trial on the use of d-sotalol in this type of patients,.Some of these results have been presented at the Congresses of the European Society of Cardiology at Stockholm (1990) and Nice (1993).     

充血性心力衰竭患者非持续性室性心动过速与心脏性死亡的关系

目的探讨充血性心力衰竭(CHF)患者非持续性室性心动过速(NSVT)与心脏性死亡之间的关系。方法对52例CHF伴NSVT患者,根据住院期间是否发生心脏性死亡,分为死亡组(13例),存活组(39例),分析两组心电图及临床特征。结果死亡组NSVT的发作阵数高,频率快,每阵持续搏动数多,QRS波时限宽,多形性VT发生率高(P<0．05～0．001);常规心电图中,死亡组室内传导阻滞发生率高,QT和QTc间期长(P<0．05～0．005);两组间心功能级别无差异(P>0．05),但死亡组左室射血分数明显低于存活组(P<0．001)。结论CHF患者伴NSVT,并具有上述特征时,有发生心脏性死亡的高度危险。     

大剂量胺碘酮对持续性室性心动过速的纠治

目的 :观察大剂量胺碘酮治疗持续性室性心动过速 ( SVT)的临床疗效及副作用。方法 :初始以胺碘酮 15 0 m g静脉注射 (静注 ) ,5～ 10 min注射完毕 ,必要时重复 1～ 2个初始量 ,继以 0 .5～ 5 m g/ min静脉维持 3～ 8d。结果 :6例 SVT均在静脉用药 2 h内得到控制 ,2 h内静脉胺碘酮用量 3 90～ 5 4 0 ( 4 68.4± 5 4 .7) m g;2 4 h内静脉平均用量 10 0 0～ 180 0 ( 14 10 .3± 3 5 6.5 ) m g,除注射局部均发生不同程度的静脉炎外 ,未见低血压、心功能恶化及致心律失常作用。结论 :短期内经静脉大剂量应用胺碘酮安全有效     

Left ventricular geometry and survival in patients with normal left ventricular ejection fraction

In hypertensive populations, left ventricular (LV) geometry, which is characterized by hypertrophy, predicts cardiovascular outcome. The left ventricle can also alter its shape by concentric remodeling (CR) in the absence of LV hypertrophy, a feature that is detected by echocardiography. This study assessed the prevalence and prognostic significance of various forms of LV geometry and changes in LV geometry over time in patients with normal LV systolic function. Retrospective analysis of a large clinical population (n = 35,602) that was referred for echocardiography was done, with all-cause mortality as the primary outcome. Abnormal LV geometry was identified in 46% of patients, with CR present in 35% (n = 12,362) and LV hypertrophy in 11% (n = 3,958). Patients with abnormal LV geometry were older and more obese compared with subjects with normal LV geometry. There was a strong relation between abnormal LV geometry and mortality, and patients with CR and LV hypertrophy exhibited considerably higher relative risk for all-cause mortality compared with subjects with normal LV geometry (relative risk [RR] 1.99, 95% confidence interval [CI] 1.88 to 2.18, p <0.0001; RR 2.13, 95% CI 1.89 to 2.40, p <0.0001, respectively). Subjects with CR who reverted to a normal geometric pattern had improved survival (RR 0.64, 95% CI 0.42 to 0.97, p = 0.03) compared with those who progressed to LV hypertrophy (RR 1.54, 95% CI 1.01 to 2.47, p = 0.05). In conclusion, CR, a form of cardiac adaptation, is frequently noted in patients with normal LV ejection fractions and confers a risk of death similar to that of LV hypertrophy. Normalization of CR is associated with better survival, whereas transition to LV hypertrophy increases mortality.     

Incessant ventricular tachycardia due to multiple cardiac rhabdomyomas in an infant with Tuberous Sclerosis

We report a case of incessant ventricular tachycardia managed successfully with medications. The transthoracic echocardiogram showed multiple cardiac rhabdomyomas involving ventricular free wall and outflow tracts. Computerized tomography of brain showed multiple subependymal tubers confirming Tuberous Sclerosis. The follow up assessment showed sinus rhythm and regressing cardiac rhabdomyomas.