From the Guidelines
Systole and diastole are the two crucial phases of the cardiac cycle, with systole being the contraction phase where the heart pumps blood out to the body, and diastole being the relaxation phase where the heart refills with blood. These phases are essential for maintaining blood circulation, delivering oxygen and nutrients, and removing waste products from the body 1.
Key aspects of systole and diastole
- Systole is characterized by the contraction of the heart muscles, which forces blood out of the heart chambers into the arteries, creating the systolic pressure measured in blood pressure readings.
- Diastole, on the other hand, is the relaxation phase where the heart muscles relax, allowing the chambers to expand and fill with blood returning from the body through the veins, creating the diastolic pressure.
- The continuous cycle of contraction and relaxation is vital for circulating blood throughout the body, with the heart beating typically 60-100 times per minute in adults at rest.
Clinical significance of systole and diastole
- Understanding systole and diastole is crucial in diagnosing and managing heart conditions, such as heart failure, where the heart's ability to contract and relax is impaired 1.
- The measurement of systolic and diastolic pressures is also important in assessing cardiovascular health, with abnormal pressures indicating potential heart problems.
- Recent studies have emphasized the importance of diastolic function in heart health, with diastolic dysfunction being a common condition in patients with heart failure and preserved ejection fraction 1.
Diagnosis and management of diastolic dysfunction
- Echocardiography is a key diagnostic tool in assessing diastolic function, with parameters such as mitral peak E-wave velocity, E/A ratio, and E/e′ ratio being used to estimate left ventricular filling pressures 1.
- Managing diastolic dysfunction involves controlling systolic and diastolic hypertension, using diuretics to control pulmonary congestion and peripheral edema, and considering the use of beta-adrenergic blocking agents, angiotensin converting enzyme inhibitors, and calcium antagonists to minimize symptoms of heart failure 1.
From the Research
Systole and Diastole Explanation
- Systole refers to the contraction phase of the heart, where the heart muscle squeezes to pump blood out of the heart and into the circulatory system 2.
- Diastole, on the other hand, refers to the relaxation phase of the heart, where the heart muscle relaxes and fills with blood 2.
Key Differences
- Systolic heart failure occurs when the heart is unable to contract effectively, leading to a decrease in cardiac output 2.
- Diastolic heart failure occurs when the heart is unable to relax and fill with blood properly, also leading to a decrease in cardiac output 2.