heart and pacemaker. cardiology

anatomical anatomy aorta aortic artery artificial atrium attack blood cardiac cardiology cardiomyopathy cardiostimulator circulation congenital coronary cut defect diagnosis disease disorder eisenmenger flow health heart heartbeat hole human hypertension medical medicine myocardium organ pacemaker physiology problem prosthesis prosthetics pulse science structure synthetic system trouble valve valves vein ventricle ventricular