im not really sure what you mean with dying heart but here are some pointers bradycardia -- slow heart rate (but regular) tachycardia -- fast heart rate (also regualr) ventricular fibrillation -- very tough to explain, usually a normal heart rhytm has one small spike, followed by one big spike, then another small spike. with ventricular fibrillation -- it s completely abnorma and out of sync -- it s all small spikes and no pause in betwen. ventricular tachycardia -- is all big spikes with no rest in between. Asystole -- is no rhythm at all i think when you say dying heart you meant heart attack -- you see, what happens with heart attack is that you get chest pain -- because blood is not able to travel to a specific muscle in our heart (because of some blockage) -- that muscle is trying to work, even if no oxygen is supplied to it -- that s what causes the chest pain. when suddenly, the pain goes away -- it could mean 2 things: good -- that the blockage has been dislodged bad -- the heart muscle died -- and that s probably what you meant with dying heart