Premature ventricular contractions
| Premature ventricular contraction | |
|---|---|
 |
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| A premature ventricular contraction marked by the arrow. | |
| Classification and external resources | |
| Specialty | Cardiology |
| ICD-10 | I49.3 |
| ICD-9-CM | 427.69 |
| DiseasesDB | 32412 |
| eMedicine | emerg/773 |
| MeSH | D018879 |
A premature ventricular contraction (PVC)—also known as a premature ventricular complex, ventricular premature contraction (or complex or complexes) (VPC), ventricular premature beat (VPB), or ventricular extrasystole (VES)—is a relatively common event where the heartbeat is initiated by Purkinje fibers in the ventricles rather than by the sinoatrial node, the normal heartbeat initiator. The electrical events of the heart detected by the electrocardiogram (ECG) allow a PVC to be easily distinguished from a normal heart beat. Although a PVC can be a sign of decreased oxygenation to the heart muscle, often PVCs are benign and may even be found in otherwise healthy hearts.
A PVC may be perceived as a "skipped beat" or felt as palpitations in the chest. In a normal heartbeat, the ventricles contract after the atria have helped to fill them by contracting; in this way the ventricles can pump a maximized amount of blood both to the lungs and to the rest of the body. In a PVC, the ventricles contract first and before the atria have optimally filled the ventricles with blood, which means that circulation is inefficient. However, single beat PVC abnormal heart rhythms do not usually pose a danger and can be asymptomatic in healthy individuals.
A PVC is a type of ectopic beat.
Single PVC are common in healthy persons. The prevalence of PVCs has been estimated to be about 1% to 4% for the general population. Age has been seen to play a major role in the occurrence of PVCs throughout the population. The prevalence is seen to be under 1% for those under the age of 11 and ranges all the way up to 69% in subjects that are older than 75 years. Older patients are more likely to experience PVCs and this may be due to its prevalence in patients with high blood pressure and heart disease, which are both commonly seen more in patients of older ages. In 101 people free of heart disease during 24 hours Holter monitoring, 39 had at least 1 PVC, and 4 at least 100. Heart disease was excluded after physical examination, chest x-ray, ECG, echocardiography, maximal exercise stress test, right- and left-heart catheterization and coronary angiography. In 122,043 United States Air Force flyers and cadet applicants during approximately 48 seconds of ECG 0.78% (952 males) had PVC within all age groups, but with increased incidence with increasing age. Ventricular ectopy is more prevalent in men than in women of the same age data from large, population-based studies indicate that the prevalence ranges from less than 3% for young white women without heart disease to almost 20% for older African American individuals with hypertension.
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