Diastolic

Diastolic is an adjective used in physiology and medicine to describe events that occur during diastole, the relaxation phase of the cardiac cycle when the heart muscle relaxes and the chambers fill with blood. During diastole, the ventricles expand as the atrioventricular valves open and filling begins, with atrial contraction contributing to ventricular preload.

Diastole follows systole, the contraction phase. The duration of diastole varies with heart rate; at higher rates it shortens. The term diastolic is often used in contrast to systolic, which relates to contraction and the ejection of blood.

In clinical practice, diastolic pressure refers to the arterial pressure during diastole and is measured as the second number in a blood pressure reading. For adults, typical targets are around 60–80 mmHg for diastolic pressure, though ideals vary with age and comorbidities. Elevated diastolic pressure is associated with increased cardiovascular risk and can reflect higher systemic vascular resistance. Extremely low diastolic pressure may impair coronary perfusion during diastole.

Diastolic dysfunction is a condition in which the left ventricle has impaired relaxation or increased stiffness, reducing filling and potentially leading to heart failure with preserved ejection fraction (HFpEF). Risk factors include aging, hypertension, obesity, diabetes, and myocardial disease. Diagnosis relies on imaging, especially echocardiography, which assesses filling patterns such as the E/A ratio and tissue Doppler velocities. Management focuses on treating underlying conditions and controlling blood pressure and heart rate, with diuretics and other medications used as appropriate to relieve symptoms and prevent progression.