Submitted by examrobotsa on Thu, 01/01/1970 - 05:30 Doctors use electrocardiogram (ECG) toestimate the volume of blood pumped by the heart per minute detect changes in the electrical impulses in the heart during its contraction and relaxationdetermine the changes in the sound pattern during opening and closure of valvescompare the sound waves resulting from vibration produced by cardiac muscles during pumping of heartstats: 0,168,72,8,168,8,56