Ventricular Premature Beats
A ventricular premature beat (ventricular ectopic beat, premature ventricular contraction) is an extra heartbeat resulting from abnormal electrical activation originating in the ventricles before a normal heartbeat would occur.
Ventricular premature beats are common, particularly among older people. This arrhythmia may be caused by physical or emotional stress, intake of caffeine (in beverages and foods) or alcohol, or use of cold or hay fever remedies containing drugs that stimulate the heart, such as pseudoephedrine. Other causes include coronary artery disease (especially during or shortly after a heart attack) and disorders that cause ventricles to enlarge, such as heart failure and heart valve disorders.
Symptoms and Diagnosis
Isolated ventricular premature beats have little effect on the pumping action of the heart and usually do not cause symptoms, unless they are extremely frequent. The main symptom is the perception of a strong or skipped beat. Ventricular premature beats are not dangerous for people who do not have heart disease. However, when they occur frequently in people who have structural heart disease, they may be followed by more dangerous arrhythmias such as ventricular tachycardia or ventricular fibrillation, which can cause sudden death.
Electrocardiography (ECG) (see Section 3, Chapter 21) is used to diagnose ventricular premature beats.
Treatment
In an otherwise healthy person, no treatment is needed other than decreasing stress and avoiding caffeine, alcohol, and over-the-counter cold or hay fever remedies containing drugs that stimulate the heart. Drug therapy is usually prescribed only if symptoms are intolerable or if the pattern of ventricular premature beats suggests a risk of progression to ventricular tachycardia or ventricular fibrillation. For example, the presence of structural heart disease or runs of consecutive ventricular beats suggest this risk. Beta-blockers are usually tried first because they are relatively safe drugs. However, some people do not want to take them because they can cause sluggishness.
After a heart attack, people who have frequent ventricular premature beats may reduce the risk of sudden death due to ventricular tachycardia or ventricular fibrillation by taking beta-blockers or undergoing angioplasty or coronary artery bypass surgery to treat coronary artery disease (see Section 3, Chapter 33). Antiarrhythmic drugs can suppress ventricular premature beats, but they also may increase the risk of a fatal arrhythmia. Therefore, doctors prescribe them only for carefully selected people who have been evaluated for risk of developing serious arrhythmias.
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