(See also Overview of Arrhythmias Overview of Arrhythmias The normal heart beats in a regular, coordinated way because electrical impulses generated and spread by myocytes with unique electrical properties trigger a sequence of organized myocardial... read more 
.)
Ventricular premature beats (VPBs), also called premature ventricular contractions (PVC), may occur erratically or at predictable intervals (eg, every 3rd [trigeminy] or 2nd [bigeminy] beat). VPBs may increase with stimulants (eg, anxiety, stress, alcohol, caffeine, sympathomimetic drugs), hypoxia, or electrolyte abnormalities.
VPBs may be experienced as missed or skipped beats; the VPB itself is not sensed but rather the following augmented sinus beat. When VPBs are very frequent, particularly when they occur at every 2nd heart beat, mild hemodynamic symptoms are possible because the sinus rate has been effectively halved. Existing ejection murmurs may be accentuated because of increased cardiac filling and augmented contractility after the compensatory pause.
Diagnosis of Ventricular Premature Beats
ECG
Diagnosis of ventricular premature beats is by electrocardiography (ECG) showing a wide QRS complex without a preceding P wave, typically followed by a fully compensatory pause.
Prognosis for Ventricular Premature Beats
VPBs are not significant in patients without a heart disorder, and no treatment is required beyond avoiding obvious triggers. Beta-blockers or ablation are offered only if symptoms are intolerable or if the VPBs are very frequent and, by inducing interventricular dyssynchrony, induce heart failure Heart Failure (HF) Heart failure (HF) is a syndrome of ventricular dysfunction. Left ventricular failure causes shortness of breath and fatigue, and right ventricular failure causes peripheral and abdominal fluid... read more 
. Other antiarrhythmics that suppress VPBs increase risk of more serious arrhythmias.
Treatment of Ventricular Premature Beats
Beta-blockers for patients with symptomatic heart failure and after myocardial infarction
In some cases, ablation
In patients with a structural heart disorder (eg, aortic stenosis Aortic Stenosis Aortic stenosis (AS) is narrowing of the aortic valve, obstructing blood flow from the left ventricle to the ascending aorta during systole. Causes include a congenital bicuspid valve, idiopathic... read more 
), treatment is controversial even though frequent ventricular premature beats (> 10/minute) correlate with increased mortality because no studies have shown that pharmacologic suppression reduces mortality.
In post-myocardial infarction patients, mortality rate is higher with class I antiarrhythmics Class I Antiarrhythmic Drugs The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more than with placebo. This finding probably reflects adverse effects of the antiarrhythmics. However, beta-blockers (class II antiarrhythmics Class II Antiarrhythmic Drugs The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more ) are beneficial in symptomatic heart failure Heart Failure (HF) Heart failure (HF) is a syndrome of ventricular dysfunction. Left ventricular failure causes shortness of breath and fatigue, and right ventricular failure causes peripheral and abdominal fluid... read more and after myocardial infarction. If VPBs increase during exercise in a patient with coronary artery disease Overview of Coronary Artery Disease Coronary artery disease (CAD) involves impairment of blood flow through the coronary arteries, most commonly by atheromas. Clinical presentations include silent ischemia, angina pectoris, acute... read more 
, evaluation for percutaneous transluminal coronary angioplasty Percutaneous Coronary Interventions (PCI) Percutaneous coronary interventions (PCI) include percutaneous transluminal coronary angioplasty (PTCA) with or without stent insertion. Primary indications are treatment of Angina pectoris... read more 
or coronary artery bypass graft surgery Coronary Artery Bypass Grafting (CABG) Frontal and lateral chest x-ray of a patient post coronary artery bypass surgery showing sternal sutures (black arrow) and surgical clips (red arrow). Coronary artery bypass grafting (CABG)... read more 
should be considered.
Ablation Ablation for Cardiac Arrhythmia The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more is offered only if symptoms are intolerable or if the VPBs are very frequent and, by inducing interventricular dyssynchrony, induce heart failure Heart Failure (HF) Heart failure (HF) is a syndrome of ventricular dysfunction. Left ventricular failure causes shortness of breath and fatigue, and right ventricular failure causes peripheral and abdominal fluid... read more .
