A) They are narrow electrocardiographic wave (QRS) complexes that are preceded by P waves.
B) In most cases, they disappear with exercise.
C) They are treated with type IC antiarrhythmics.
D) They may represent a risk for sudden death in healthy patients.
E) Caffeine use is not associated with PVCs
Answer: B ( In most cases, they disappear with exercise.)
Discussion: Premature ventricular complexes (PVCs) are abnormal ventricular beats that are characterized by wide QRS complexes, which are usually not preceded by P waves.
In patients with normal hearts, PVCs usually disappear with exercise. If the patient remains asymptomatic and there is no organic heart disease, no further treatment is necessary.
If PVCs are frequent, electrolyte abnormalities and heart disease should be excluded. Patients with frequent,
repetitive, or multiform PVCs and underlying heart disease are at increased risk for sudden death because of cardiac arrhythmia (particularly ventricular fibrillation). Without underlying cardiac disease, bigeminy and trigeminy are considered benign rhythms. Treatment of PVCs is controversial but should be reserved for symptomatic patients. If MVP, hypertrophic obstructive cardiomyopathy, prolonged QT interval, LVH, or CAD is present, a trial of B blockers can be used. Types IA (quinidine, procainamide) and IB (lidocaine, mexiletine) antiarrhythmic agents may be used; however, they are associated with a high incidence of side effects and can make the arrhythmias worse. Type IC agents (flecainide, propafenone) should not be used because of their potential for increased mortality rates. Elimination of exogenous catecholamines, sympathomimetic amines, alcohol, and caffeine may decrease symptoms. In general, antiarrhythmic drug therapy is rarely necessary.