Ventricular fibrillation prevention

Following resuscitation from ventricular fibrillation (VF) or pulseless VT, ICD implantation is a proven strategy for the prevention of recurrent SCD. Three prospective, randomized, controlled trials, the Antiarrhythmics Versus Implantable Defibrillators (AVID) study, the Canadian Implantable Defibrillator Study (CIDS), and the Cardiac Arrest Study Hamburg (CASH), support this strategy [27-29]. 

ICD implantation is recommended for prevention of sudden cardiac death in patients with ARVC with documented sustained VT or ventricular fibrillation. Drug therapy with amiodarone or stalol can be effective in selected patients with ARVC. 

Unlabeled Uses Control of hemodynamicallystableventriculartachycardia, control of rapid ventricular rate due to accessory pathway conduction in preexcited atrial arrhythmias, conversion of atrial fibrillation to normal sinus rhythm, in cardiac arrest with persistent ventricular tachycardia or ventricular fibrillation, paroxysmal supraventricular tachycardia, polymorphic ventricular tachycardia or wide complex tachycardia of uncertain origin, prevention of postoperative atrial fibrillation... 

Lidocaine is the agent of choice for termination of ventricular tachycardia and prevention of ventricular fibrillation after cardioversion in the setting of acute ischemia. However, routine prophylactic use of lidocaine in this setting may actually increase total mortality, possibly by increasing the incidence of asystole, and is not the standard of care. Most physicians administer IV lidocaine only to patients with arrhythmias. 

Lidocaine Sodium channel (INa) blockade Blocks activated and inactivated channels with fast kinetics does not prolong and may shorten action potential Terminate ventricular tachycardias and prevent ventricular fibrillation after cardioversion IV first-pass hepatic metabolism reduce dose in patients with heart failure or liver disease Toxicity Neurologic symptoms... 

Although an intermediate endpoint is associated with clinical benefit/ this benefit may be more than offset by the adverse effects of drug therapy when the ultimate outcome is considered. For example/ ventricular fibrillation is associated with increased mortality in the setting of acute myocardial infarction. The demonstration that lidocaine effectively prevents ventricular fibrillation in myocardial infarction patients at first provided a rationale for treating these patients prophylactically with this drug (7). However/ subsequent meta-analyses of several studies by MacMahon (8) and Hine (9) indicated that this use of lidocaine therapy actually worsens patient... 

Lie KI, Wellens HJ, van Capelle FJ, Durrer D. Lidocaine in the prevention of primary ventricular fibrillation A double-blind, randomized study of 212 consecutive patients. N Engl J Med 1974 291 1324-6. 

Wyman MG, W5unan RM, Cannom DS, Criley JM. Prevention of primary ventricular fibrillation in acute myocardial infarction with prophylactic lidocaine. Am J Cardiol 2004 94 545-51. 

Uses of electrical conversion in supraventricular and ventricular tachycardia, ventricular fibrillation and atrial fibrillation and flutter. Drugs can be useful to prevent a relapse, e.g. sotalol, amiodarone. 

Tachycardia and a rise in blood pressure are occasionally seen. Other supraventricular and ventricular dysrhythmias are much less common. Ventricular fibrillation associated with suxamethonium is usually the result of hyperkalemia, but has also been reported in hypercalcemia (22) and is often seen in the course of malignant hyperthermia. Atropine, especially when given intravenously just before suxamethonium, is the most effective agent for the prevention of dysrhythmias. Hexafluorenium, D-tubocurarine, pancuronium, and other non-depolarizer blockers have also been reported as being effective in prevention. Severe hypotension can occur in patients with anaphylactoid reactions. 

Trans-resveratrol (43) extract prepared from Polygonum cuspidatum (Polygonaceae) showed reduction of reperfusion-induced ventricular fibrillation in vitro) from its control value of 83% to 75% when rats were orally treated with 50mg/kg and lOOmg/kg dose. Thus, it can be a potential alternative to conventional HRT for cardioprotection and osteoporosis prevention [38]. 

Original It is a familiar nightmare a person suffers a heart attack, and as the ambulance fights heavy traffic, the patient dies. In fact, 350,000 American heart-attack victims each year die without ever reaching a hospital. The killer in many cases is ventricular fibrillation, uncoordinated contraction of the heart muscle. Last week a team of Dutch physicians reported in The New England Journal of Medicine that these early deaths can often be prevented by administration of a common heart drug called lido-caine, injected into the patient s shoulder muscle by ambulance paramedics as soon as they arrive on the scene. 

R-8I8 (17) prevented chloroform-induced ventricular fibrillation in mice as well as arrhythmias caused by hydrocarbon-epinephrine, ouabain, aconitine and coronary occlusion in dogs.5° The activity of numerous analogs in the mouse chloroform test has been described.57... 

The indications for implantation of an ICD have expanded considerably (Table 17-7). Initially, its efficacy was evaluated in patients who had already suffered a documented episode of ventricular tachycardia or ventricular fibrillation (secondary prevention), but now primary prevention trials have been published or are being planned. These results will help clinicians in choosing the proper therapy for patients with life-threatening arrhythmias. For instance, the Sudden Cardiac Death in Heart Failure Trial (SCD-Heft) is a primary prevention trial that evaluated survival in patients withLV dysfunction... 

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