Diastolic is an adjective used in the field of medicine and physiology to describe a specific aspect of the cardiac cycle. It relates to the phase of the heart's cycle when the heart muscles relax and the ventricles, the lower chambers of the heart, are filling with blood.
Within the context of blood pressure measurement, diastolic refers to the bottom number recorded, such as in a reading of 120/80 mmHg. In this case, the diastolic pressure is the lower number, 80, representing the pressure when the heart is in the relaxation phase. The term diastolic is often used in conjunction with systolic, the other number in a blood pressure reading, which reflects the pressure in the arteries during the contraction phase when the heart is pumping blood.
Understanding the diastolic pressure is crucial in monitoring an individual's overall cardiovascular health. High diastolic blood pressure, or diastolic hypertension, is considered a risk factor for heart disease, stroke, and other cardiovascular conditions. Conversely, low diastolic blood pressure, or diastolic hypotension, may be an indication of inadequate blood flow to the heart and other organs.
Diastolic is also used in electrocardiography (ECG/EKG) to describe a phase of cardiac electrical activity. It pertains to the resting phase of the heart muscle between two consecutive contractions. EKG readings help to evaluate the heart's electrical activity and diagnose various cardiac conditions, including arrhythmias and ischemic heart disease.
In summary, diastolic is an adjective that describes the relaxed phase of the cardiac cycle, the measurement of blood pressure during this phase, and a stage of cardiac electrical activity during an electrocardiogram.
