phases of the cardiac cycle - diastole, atrial systole and atrial diastole. circulation of blood through the heart

heart cycle medical atrium biology organ illustration medicine cardiology ventricle diagram human anatomy cardiac health pulmonary contraction attack right problem ecg healthy vector system heartbeat body valve flow muscle blood artery cardiovascular veins aortic myocardium normal tissue disease healthcare systole pulse pressure left diastole anatomical pump circulation aorta vein atrial