Question

Systole is contraction of heart muscle. The atria contract independently of the ventricles. When is ventricular systole with respect to the QRS wave/complex of the ECG?

Answer 1

Ventricular systole begins just after the onset of the QRS complex on an ECG, which is when the ventricles contract and pump blood out of the heart.

Step-by-step explanation:

Ventricular systole in the heart occurs with respect to the QRS complex on an electrocardiogram (ECG). The QRS complex represents the depolarization of the ventricles, which triggers the contraction of these chambers. Specifically, ventricular systole begins just after the start of the QRS complex. This is the period during which the ventricles contract and pump blood out of the heart to the lungs and the rest of the body, following the end of atrial systole and the relaxation of the atria.

The ECG is a vital tool in understanding the cardiac cycle, which includes both systole and diastole for both the atria and ventricles. Proper coordination of these phases is critical for efficient blood circulation. Ventricular systole is an essential phase of the cardiac cycle as it ensures that blood is ejected into the aorta and pulmonary artery to be delivered to the body and lungs.

Answer 2

Answer: The Ventricular systole is represented in the ECG by the R wave.

Step-by-step explanation:

The P Wave represents the Atrial Systole.

The R Wave represents the Ventricular Systole.

The T Wave represents the Ventricular Diastole.

Which is why the R-R complex is one of the methods used to determine the Heart Rate on the ECG. The Atrial Diastole usually is not shown on the ECG, but in some patients may be normal.