User:Mr. Ibrahem/Premature ventricular contraction

A premature ventricular contraction (PVC) is an early extra beat that arise from the ventricle of the heart. They often result in no symptoms but may be felt as a "skipped beat" in the chest. Others report tiredness and lightheadedness. Occasional PVCs do not pose a danger; while, frequent PVCs can represent or result in heart problems. If a prolonged QT is present, Torsades de Pointes may occur.

Generally they are a normal phenomenon. Triggers may include anxiety, alcohol, stimulants including caffeine, electrolyte abnormalities, low oxygen, and high CO2. Underlying heart disease, including a heart attack, mitral valve prolapse, and myocarditis, is also a risk factor. Diagnosis is by electrocardiogram (ECG), which generally shows a QRS complex greater than 120 ms. Generally they occur early and are followed by a pause. If more than 10% of heartbeats are PVCs an ultrasound of the heart is recommended.

Often no treatment is needed. In those who are bothered beta blockers or certain calcium channel blockers may be used. If this is not effective an antiarrhythmic medication or radiofrequency ablation may be considered. They are common. They are present on an ECG in about 0.5% of those under 20 and 2.2% of those over 50 years old.