BIOL 3327 Lecture Notes - Lecture 42: Ventricular Fibrillation, Atrial Flutter, Ventricular Tachycardia
15 Jul 2020
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Document Summary
Think of the whole heartbeat occurring as a wave. Step 1: action potential at the sinus node; begins the whole contraction. Step 2: the stimulus spreads around 2 pathways and across the atrial surface until it reaches the av node. Step 3: 100 millisecond delay at the av node because it allows the atrial muscle to contract and start to push the blood into the ventricles. If you don"t have this delay, you don"t fully fill the ventricle because you don"t have enough time. By the end, the elapsed time is 150msec. Step 4: the next impulse that travels down the center of the heart within the av bundle and his-purkinje fibers. There"s a moderator band that runs down the middle of the heart. An arrhythmia is any change in the heart rate, the rhythm, the impulse generation or some kind of conduction through the heart.
