title: Can a demand pacemaker really sense concealed ventricular extrasystoles?
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D004562:Electrocardiography; D006801:Humans