The electrical events of the cardiac cycle give important insight into the mechanical events. Recall that in order for a muscle to contract, it must receive an electrical stimulus. This is especially important in the heart, since we rely on the contraction of the atria and ventricles to move blood. T/F

-The pacemaker region of heart is called SA node. It shows spontaneous depolarization that causes action potentials and automatic rhythmic beating of heart.

- These impulses which travel through the cardiac muscle produce electric currents. These electrical currents can be detected by placing electrodes on the skin and recorded as electrocardiogram (ECG). The electrical current actually passes through the body fluids to the body surface where it is amplified in order to be detected.

- The waves in ECG represents the mechanical events going on in heart.

- Like the P wave in ECG is a small upwards wave and it represents contraction of both the atrial chambers.

- P wave is followed by the QRS wave/complex which represents the contraction of both the ventricles.

- There is a small upwards curve called T wave which represents the repolarization of ventricles. When the T wave ends, it marks the end of ventricular systole.

So yes, the electrical events of the cardiac cycle give important insight into the mechanical events.