Ventricular ectopy

Patients with complex ventricular ectopy should not receive type I or III antiarrhythmic drugs. 

In sinus bradycardia or incomplete heart block, lidocaine administration for the elimination of ventricular ectopy without prior acceleration in heart rate (eg, by atropine, isoproterenol or electric pacing) may promote more frequent and serious ventricular arrhythmias or complete heart block. Use with caution in patients with hypovolemia and shock, and all forms of heart block. 

Hypertension, hypotension, arrhythmias such as sinus bradycardia, atrial fibrillation, varying degrees of AV block, ventricular ectopy including nonsustained tachycardia, and ECG abnormalities have been observed,... 

Flecainide is very effective in suppressing premature ventricular contractions. However, it may cause severe exacerbation of arrhythmia even when normal doses are administered to patients with preexisting ventricular tachyarrhythmias and those with a previous myocardial infarction and ventricular ectopy (see The Cardiac Arrhythmia Suppression Trial). The drug is well absorbed and has a half-life of approximately 20 hours. Elimination is both by hepatic metabolism and by the kidney. The usual dosage of flecainide is 100-200 mg twice a day. 

Autonomic symptoms are most common and include gastrointestinal disturbance (nausea, diarrhea), general somatic distress (myalgias, malaise, headache, rhinorrhea), sleep disturbances (insomnia, nightmares), and cardiovascular symptoms (arrhythmias, ventricular ectopy). Psychotic decompensation, withdrawal mania, and general anxietylike symptoms have been attributed to abrupt withdrawal of cyclic antidepressants. 

Klein RC, House M, Rushforth N. Efficacy and safety of oral cibenzoline in treatment of ventricular ectopy. Clin Res 1984 32 9A. 

De Soyza N, Murphy M, Sakhaii M, Treat L. The safety and efficacy of propafenone in suppressing ventricular ectopy. In Shlepper M, Olsen B, editors. Cardiac Arrhythmias. Berlin Springer Verlag, 1983 221. 

The CAST was initiated by the NIH in 1987 to determine if suppression of ventricular ectopy with encainide, flecainide, or moricizine could decrease the incidence of death from arrhythmia in patients who had suffered an MI. Entrance criteria included documented MI between 6 days and 2 years prior to enrollment and six or more PVCs per hour without runs of ventricular tachycardia greater than 15 beats in length. Also, patients were required to have an ejection fraction of 55% or less if recruited within 90 days of MI or 40% or less if recruited 90 days or more after MI. Patients with an ejection fraction of less than 30% were randomized only to encainide or moricizine. Patients were randomized to receive drug therapy or placebo after demonstrating PVC suppression with one of the agents. The drug and dose were determined during an open-label dose-titration phase that preceded randomization. 

Despite the discouraging results of the CAST, post-MI patients with complex ventricular ectopy remain at risk for death. Other drugs besides type Ic drugs have been studied, including sotalol. Sotalol is marketed as a racemic mixture of a D- and L-isomer both are type in potassium blockers, but the L-isomer has /3-blocking actions. Chronic therapy with D-sotalol was studied in patients with remote MI complicated by complex ectopy in the Survival With Oral D-Sotalol (SWORD) trial. Unlike in the CAST, D-sotalol treatment was not designed to cause PVC suppression, yet (as in the CAST) the trial was halted prematurely because of excessive mortality in the treatment arm. Again, the presumed reason for this observation was D-sotalol-related pro arrhythmia. Currently, only two antiarrhythmic... 

Frolkis JP, Pothier CE, Blackstone EH, Lauer MS. Frequent ventricular ectopy after exercise as a predictor of death. N Engl JMed2003 348(9) 781-90. 

Ventricular fibrillation is a very common dysrhythmia in a code situation, and lidocaine is the drug of choice because it suppresses ventricular ectopy. 

The Cardiac Arrhythmia Suppression Trial (CAST) highlighted the importance and awareness of proarrhythmia. The main finding of CAST was that, despite elimination of complex ventricular ectopy after myocardial infarction, mortality was significantly higher in patients treated with encainide or flecainide. Others have reported that the overall risk of cardiac mortality is higher, presumably due to proarrhythmia, in patients treated with Type la antiarrhythmics for atrial fibrillation who have con-... 

Noninvasive markers have been evaluated to help identify high-risk patients. Ventricular ectopy is associated with an increased risk for cardiac arrest. Premature ventricular contractions (PVCs) and nonsustained ventricular tachycardia identify increased risk for death, even in patients with no obvious heart disease (40-43). PVCs and nonsustained ventricular tachycardia provide... 

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