Treatment of ventricular arrhythmias

The term ventricular arrhythmia denotes various disorder in the cardiac rhythm--from isolated monomorphic ventricular extrasystoles to ventricular flutter and fibrillation. The choice of therapy of ventricular arrhythmias is primarily based on prognostic aspects. Ventricular tachycardias represent the main cause of sudden cardiac death, which is responsible for more than 60% of all deaths for cardial causes. In the industrially advanced countries the ventricular tachyarrhythmias represent more than 90% of cases based on coronary disease. The prevention of sudden death is directed particularly to prevention and therapy of ischaemic heart disease. The prognostic classification divides ventricular tachycardias into benign, potentially malignant and malignant ones, respectively. The benign arrhythmias do not require therapy. In the malignant (i.e. potentially lethal) ventricular tachyarrhythmias the implantation of cardioverter-defibrillator represents the most efficient treatment. In the largest group of patients with potentially malignant ventricular arrhythmias the present risk-oriented stratification enables a partial identification of persons with markedly increased risk of sudden death. They may be considered for preventive implantation of cardioverter-defibrillator. In some patients the therapeutic effect is reached by application of various therapeutic methods including a combination of pharmacological and non-pharmacological therapy, which also includes catheterization or surgical ablation of the arrhythmogenic substrate. A corresponding attention should be devoted to the basal cardial disease.     

Treatment of ventricular arrhythmias

Treatment of ventricular arrhythmias     

室性心律失常的治疗

室性心律失常是临床上十分常见的心律失常,主要包括室性早搏、室性心动过速、心室扑动和心室颤动.室性心律失常不仅见于器质性心脏病病人,也可发生于非器质性心脏病患者,如特发性右心室流出道室性心动过速和特发性左心室室性心动过速.     

Treatment of ventricular arrhythmias with oral tocainide

This is a report of a multicenter open study of the use of tocainide, a new lidocaine-like antiarrhythmic with a high oral bioavailability, in the treatment of life-threatening ventricular arrhythmias refractory to other therapy. The majority of patients have received 1,200 to 2,400 mg daily in divided doses and have been treated for over 6 months and some for longer than 3 years. Overall, 61% of the patients responded successfully to tocainide therapy. In the 252 patients with documented, severe, symptomatic arrhythmias, 71% responded, and the majority (87%) showed a total abolition of symptomatic events. Gastrointestinal and central nervous system events were the most common adverse experiences, and 11% had to discontinue therapy; however, the remaining 89% tolerated tocainide satisfactorily.     

植入型心律转复除颤器治疗恶性室性心律失常

目的 报道植入型心律转复除颤器治疗恶性室性心律失常５例次临床应用经验。方法 采用经静脉途径为４例恶性室性心律失常患者植入５台植入型心律转复除颤器,并随访３～６４个月。结果 随访期间１例患者发生１次室性心动过速并经低通量电击复律成功和１次误放电,余患者经抗心律失常药物治疗无症状发作。结论 植入型心律转复除颤器有效地治疗恶性室性心律失常,预防心脏性猝死的发生,适当的抗心律失常药物可减少植入型心律转复除     

Treatment of choice and long-term prognosis for ventricular arrhythmias

Treatment of choice and long-term prognosis of the patients with ventricular arrhythmias are described in terms of prevention of sudden cardiac death and/or recurrence of life-threatening arrhythmias(ventricular tachycardia and ventricular fibrillation). 1) As to the long-term prognosis of ventricular tachyarrhythmias, presence of organic heart disease and degree of cardiac dysfunction are major determining factors. 2) The prognosis of patients with ventricular arrhythmias depends on how sudden cardiac death and life-threatening arrhythmias can be prevented. Among various methods, the electrophysiological test and its guided-therapy for antiarrhythmic drugs are now believed to be the most effective method for the prediction and prevention of the life-threatening events. We propose that the signal averaged electrocardiography is the best screening method as non-invasive approach for the selection of patients undergoing the electrophysiological test. 3) There are still certain limitations as to the prediction of sudden cardiac death and/or prevention of recurrent life-threatening arrhythmias by antiarrhythmic drug treatments in the certain numbers of patients depending on their basal cardiac disease and functional impairment. At present, catheter ablation procedure and implantable cardioverter defibrillator are the choice of the treatment in these cases. 4) In addition to conventional antiarrhythmic drugs, the treatment for the basal cardiac condition is mandatory for the long-term prognosis in the patients with ventricular arrhythmias.     

Treatment and prophylaxis of ventricular arrhythmias in acute myocardial infarction

Remarkable advances have been made in the management of cardiac disease in the last 20 years, but antiarrhythmic drug strategy in the acute phase of myocardial infarction remains less than satisfactory. Primary ventricular fibrillation (VF), once considered predictable on the basis of detection of “warning arrhythmias,” cannot be anticipated. Management must be either expectant or prophylactic. Restriction of drug use to selected patients and the apparent lack of effect of VF on late prognosis argue for the former approach, yet safe and effective prevention of VF is an attractive therapeutic goal. High-dose intravenous lidocaine probably offers efficacy but the risk-benefit ratio of this regimen is still debated. Adoption of a prophylactic regimen mandates drug administration to a large number of patients who either are not at risk of developing VF (noninfarct patients) or who are destined not to develop VF (70 to 95% of infarct patients). Ventricular arrhythmias other than VF are common in acute infarction and, for emotional rather than scientific reasons, often are aggressively treated. Little evidence exists to support this management. Few ventricular arrhythmias at this time in infarction have either immediate importance or prognostic significance. Reevaluation of antiarrhythmic drug use and arrhythmia treatment in acute myocardial infarction is long overdue. However, there is a paucity of controlled data upon which to base new strategies, and clinical research in this field is hampered by ethical considerations, by rigidly held but unscientifically based beliefs and by a lack of fundamental knowledge of arrhythmia mechanisms and their significance.     

Mapping of ventricular arrhythmias

Mapping of ventricular arrhythmias is essential for their reliable surgical and ablative management. Activation mapping is the most widely used technique but demands induction of the arrhythmia. Mapping strategies that can identify an arrhythmogenic substrate in sinus rhythm are clinically attractive but require further investigation before their widespread application.     

Ablation of ventricular arrhythmias

Ventricular arrhythmias (VAs) commonly occur in patients with structural heart disease and may present as ventricular premature depolarizations (VPDs), monomorphic ventricular tachycardia (VT), or polymorphic VT/ventricular fibrillation. Idiopathic VAs can also occur in patients with normal hearts. This review explores the etiology, clinical presentation, and management strategies for different types of VAs. Medical and invasive treatment strategies are discussed, and different approaches to catheter ablation are outlined. While ablation of VPDs and idiopathic VT provides a cure for the majority of patients, investigation is ongoing to define the optimal ablation strategy for patients with scar-related VT.     

Treatment of ventricular arrhythmias in patients with manifestations of heart failure

A comparative study of the efficiency of digoxin and "pure" antiarrhythmic agents was carried out in 56 patients with ventricular arrhythmias and signs of circulatory insufficiency (CI). Digoxin had arrhythmogenic effect in 20% of the patients, which was twice as frequent in the marked CI group. "Pure" anti-arrhythmic agents were effective in 47% (ritmilen) to 71% (cordaron), and etmozin, in 63% of the patients, while adverse myocardial inotropic effect was only produced by ritmilen. Combined use of etmozin, ritmilen or cordaron with digoxin increases their antiarrhythmic efficiency.     

Management of ventricular arrhythmias

Underlying causes of ventricular tachycardia (VT) or complex ventricular arrhythmias (VA) should be treated if possible. Anti-arrhythmic drugs should not be used to treat asymptomatic patients with complex VA and no heart disease. Beta blockers are the only antiarrhythmic drugs that have been documented to reduce mortality in patients with VT or complex VA. Radiofrequency catheter ablation of VT has been beneficial in treating selected patients with arrhythmogenic foci of monomorphic VT. The automatic implantable cardioverter-defibrillator (AICD) is the most effective treatment for patients with life-threatening VT or ventricular fibrillation. The American College of Cardiology/American Heart Association class I indications for an AICD are discussed. Other indications for an AICD are discussed. Patients with AICDs should be treated with biventricular pacing, not with dual-chamber rate-responsive pacing at a rate of 70/minute. Patients with AICDs should be treated with beta blockers, statins, and angiotensin-converting enzyme inhibitors or angiotensin blockers.