ANATOMY

Detailed explanation-1: -Systole is when the heart muscle contracts. When the heart contracts, it pushes the blood out of the heart and into the large blood vessels of the circulatory system. From here, the blood goes to all of the organs and tissues of the body. During systole, a person’s blood pressure increases.

Detailed explanation-2: -Cardiac cycle events can be divided into diastole and systole. Diastole represents ventricular filling, and systole represents ventricular contraction/ejection. Systole and diastole occur in both the right and left heart, though with very different pressures (see hemodynamics below).

Detailed explanation-3: -During systole, the two ventricles develop pressure and eject blood into the pulmonary artery and aorta. At this time the AV valves are closed and the semilunar valves are open. The semilunar valves are closed and the AV valves are open during diastole.

Detailed explanation-4: -Systole is best described as the period that starts when the heart is maximally filled with blood and then subsequently ejected from the ventricle to the aorta whereupon the aortic valve closes. The volume of blood ejected from the heart is the stroke volume (SV).

Detailed explanation-5: -Ventricular systole (see image below) follows the depolarization of the ventricles and is represented by the QRS complex in the ECG. It may be conveniently divided into two phases, lasting a total of 270 ms.