title: Mechanism of Wenckebach A-V block and the obligatory ventricular echo.
mesh_terms: D000200:Action Potentials; D004562:Electrocardiography; D006326:Heart Auscultation; D006327:Heart Block / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology; D006352:Heart Ventricles; D006801:Humans; D008564:Membrane Potentials; D010138:Pacemaker, Artificial; D013997:Time Factors