What is diastole and what affects it?

Diastole is a phase in the cardiac cycle in which the heart muscle relaxes and allows the heart chambers to fill with blood. Diastole consists of two main phases:

  • Atrial Diastole: This phase occurs when the atrium or atrium of the heart relaxes and allows blood to enter the atrium from large veins such as the superior and inferior vena cava. During atrial diastole, the atrioventricular (AV) valve located between the atrium and ventricle opens, allowing blood to flow from the atrium to the ventricle.
  • Ventricular Diastole: After blood enters the ventricles during atrial diastole, ventricular diastole begins. In this phase, the ventricles relax and allow blood to fill from the atria to the ventricles. During ventricular diastole, the AV valves close and the aortic valve (in the left ventricle) or pulmonary valve (in the right ventricle) also closes. This prevents blood from flowing back into the atrium and forces blood to flow into the main blood vessels, such as the aorta and pulmonary artery.

Diastole is an important relaxation phase in the cardiac cycle that allows the ventricles to fill with blood before the next contraction phase called systole. The process of alternating diastole and systole allows efficient blood circulation throughout the body.

What’s that

Diastole is the period of time in the cardiac cycle where the heart is largest and has the widest shape. In one cardiac cycle, diastole is the time period between contraction (systole) and dilatation (diastole). During diastole, the heart expands and has its widest shape, before returning to contraction during systole. Diastole is a very important period for distributing blood and oxygen throughout the body.


Diastole refers to the relaxation phase of the cardiac cycle when the heart muscle is at rest and the heart chambers fill with blood. Here are five questions and answers related to diastole:

1. What happens during diastole?

During diastole, the heart muscles relax, allowing the ventricles to expand and fill with blood. This is an important phase because it allows the heart to recharge and prepares it for the next contraction.

2. What are the types of diastole?

There are two types of diastole: early diastole and late diastole. Early diastole occurs immediately after the heart contraction (systole), while late diastole occurs just before the next contraction. End diastole allows optimal filling of the heart chambers.

3. What is the diastolic blood pressure?

Diastolic blood pressure is the second number in a blood pressure reading and represents the pressure in the arteries when the heart is at rest (during diastole). This is an important indicator of heart health.

  4. What is the difference between diastole and systole?

Diastole and systole are two phases of the cardiac cycle. Diastole is the relaxation phase when the heart chambers are filled with blood, while systole is the contraction phase when the heart pumps blood out to the body. Together, they form a complete heartbeat.

5. What factors influence diastole?

Several factors can influence diastole, including heart rate, blood volume, and vascular resistance. For example, an increase in heart rate can shorten the duration of diastole, thereby reducing the time available for ventricular filling.

These questions and answers provide a basic understanding of diastole and its importance in the cardiac cycle. Remember, if you have any further questions or need clarification, don’t hesitate to ask!