diastole
Pronunciation: die-AS-toe-lee
The phase of the cardiac cycle when the heart muscle relaxes and the chambers fill with blood.
Full Definition
Diastole is the relaxation phase of the cardiac cycle, occurring between heartbeats when the ventricles fill with blood. During ventricular diastole, the aortic and pulmonary valves close while the mitral and tricuspid valves open, allowing passive filling of the ventricles. Diastolic function is assessed through echocardiography and can be impaired in conditions such as hypertensive heart disease, diabetes, or aging. Diastolic blood pressure represents the pressure in arteries during this relaxation phase.
Usage
Usage note: Always pair with corresponding systolic measurements when discussing blood pressure or cardiac function.
In Context
- "Echocardiography revealed impaired diastolic filling with elevated E/A ratio." — echocardiogram report
- "The diastolic murmur was best heard at the left sternal border during expiration." — physical examination note