Unsensed premature ventricular contractions.
D001145:Arrhythmias, Cardiac / Q000209:etiology*; D004562:Electrocardiography; D006327:Heart Block / Q000628:therapy*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D010138:Pacemaker, Artificial; D013575:Syncope / Q000628:therapy*