The heart and the cardiac cycle
THE HEART AND THE CARDIAC CYCLE · IMAT Doutor1 / 1
In complete atrioventricular block, no impulse crosses from the atria to the ventricles. What is observed?
A
The ventricles stop beating altogether, because they have no pacemaker tissue of their own, and death is immediate
B
Atria and ventricles both beat at the sinoatrial rate, but out of phase, because the impulse reaches the ventricles through the septum
C
The heart rate rises, because the atrioventricular delay disappears and the ventricles are driven directly by the sinoatrial node
D
Only the atria continue to beat, and the ventricles fill passively and empty only when atrial pressure pushes blood onward
E
The atria beat at the sinoatrial rate and the ventricles beat independently, more slowly, driven by a pacemaker below the block
Keyboard: A–E to choose, Shift + letter to cross out, Enter to confirm.