Ventricular premature contractions

A premature ventricular contraction (PVC) 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. PVCs may cause no symptoms at all, but they may also be perceived as a 'skipped beat' or felt as palpitations in the chest. Single beat PVC abnormal heart rhythms do not usually pose a danger. A premature ventricular contraction (PVC) 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. PVCs may cause no symptoms at all, but they may also be perceived as a 'skipped beat' or felt as palpitations in the chest. Single beat PVC abnormal heart rhythms do not usually pose a danger. The electrical events of the heart detected by the electrocardiogram (ECG) allow a PVC to be easily distinguished from a normal heart beat. However, very frequent PVCs can be symptomatic of an underlying heart condition (such as arrhythmogenic right ventricular cardiomyopathy). Furthermore, very frequent (over 20% of all heartbeats) PVCs are considered a risk factor for arrhythmia-induced cardiomyopathy, in which the heart muscle becomes less effective and symptoms of heart failure may develop. Echocardiography (ultrasound of the heart) is therefore recommended in people with PVCs. If PVCs are frequent or troublesome, medication (beta blockers or certain calcium channel blockers) may be used. Very frequent PVCs may require invasive treatment with radiofrequency ablation. Although there are many possible symptoms associated with PVCs, PVCs may also have no symptoms at all. PVCs may be perceived as a skipped heart beat, a strong beat, palpitations, lightheadedness. They may also cause chest pain, a faint feeling, fatigue, or hyperventilation after exercise. Symptoms may be more pronounced at times of stress. Women may be more aware of PVCs at the time of the menstrual period. Premature ventricular contractions may be associated with underlying heart disease, and certain characteristics are therefore elicited routinely: the presence of signs of heart disease or a known history of heart disease (e.g. previous myocardial infarction), as well as heart disease or sudden cardiac death in close relatives. PVCs and palpitation associated with syncope (transient loss of consciousness) or provoked by exertion are also concerning. Physical examination is focused on identifying evidence of underlying heart disease. Premature ventricular contractions can occur in a healthy person of any age, but are more prevalent in the elderly and in men. In a very significant proportion of people they occur spontaneously with no known cause. Some possible underlying causes of PVCs include: