Different groups of cells depolarize at different rates. The rate of depolarization of SA node cells is faster than the rate of depolarization of AV node cells. ... If both the SA node and AV node fail, the Purkinje fibers have a modest level of automaticity (20 beats/minute) that may still reach threshold
Occurs when an area heart muscle dies or is permanently damaged because if an inadequate supply of oxygen to that area; also known as heart attack.
Myocardial Infarction (Heart Attack)
It occurs when an area heart muscle dies or is permanently damaged because if an inadequate supply of oxygen to that area. It is a life threatening emergency.
Symptoms of myocardial infarction are anxiety, shortness of breath, tightness in chest, dizziness and etc.
Hope it helps you!\(^ᴥ^)/