Diastole is the phase of the cardiac cycle when the ventricles relax and fill with blood. It is a core physiology concept used across cardiology, critical care, and cardiovascular imaging. Clinicians discuss Diastole when interpreting blood pressure, heart sounds, and echocardiography findings. It is especially important in conditions involving diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF).

Systole is the phase of the cardiac cycle when the heart muscle contracts to eject blood. It is a core physiology concept used across cardiology, critical care, and anesthesia. Clinicians use it when describing blood pressure, heart sounds, murmurs, and cardiac imaging findings. It is commonly referenced in exams, echocardiography reports, and bedside assessment.

Cardiac Cycle is the repeating sequence of mechanical and electrical events that moves blood through the heart and circulation. It describes how the atria and ventricles fill, contract, and relax with each heartbeat. It is a core physiology concept used across cardiology, including bedside examination, echocardiography, electrocardiography (ECG), and hemodynamics. It is commonly referenced when interpreting heart sounds, murmurs, blood pressure, and ventricular function.

Mean Arterial Pressure is the average arterial blood pressure over one cardiac cycle. It is a core cardiovascular physiology concept used to estimate organ perfusion pressure. It is discussed in acute care, perioperative medicine, cardiology, and critical care monitoring. It is commonly derived from systolic blood pressure and diastolic blood pressure or measured directly with an arterial catheter.

Pulse Pressure is the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP). It is a hemodynamic measure used in cardiovascular physiology and clinical assessment. It is commonly discussed during vital sign interpretation, bedside monitoring, and risk assessment. It helps clinicians think about stroke volume, arterial compliance, and overall circulatory status.

Diastolic Pressure is the lower number in a blood pressure reading (for example, “120/80”), measured in millimeters of mercury (mmHg). It reflects the arterial pressure during cardiac diastole, when the ventricles relax and fill. It is a core physiologic concept used in cardiovascular examination, emergency care, and chronic disease management. It is most commonly assessed with a blood pressure cuff (sphygmomanometer) or an intra-arterial catheter in critical care.

Systolic Pressure is the peak arterial pressure generated during ventricular systole. It is a core cardiovascular physiology concept and a standard vital sign in clinical medicine. It is commonly measured as part of blood pressure assessment in outpatient care, inpatient monitoring, and emergency triage. It is used in risk assessment, hemodynamic evaluation, and treatment monitoring across many cardiac and non-cardiac conditions.

Blood Pressure is the force of circulating blood against arterial walls. It is a core cardiovascular physiology concept and a routinely measured clinical vital sign. It is used in diagnosis, risk assessment, and monitoring across acute and chronic care. It is most commonly assessed with a cuff device or, in selected settings, an arterial catheter.

Heart Rate is the number of heartbeats per minute. It is a core physiologic vital sign used in acute care, outpatient medicine, and perioperative monitoring. It reflects cardiac electrical activation and mechanical pumping in the cardiovascular system. It is commonly assessed by pulse examination, electrocardiogram (ECG), and continuous monitoring.

Ejection Fraction is a measurement of how much blood a ventricle ejects with each heartbeat. It is most commonly discussed for the left ventricle in cardiovascular physiology and heart failure. It is used in diagnostic testing, risk stratification, and longitudinal monitoring. It is typically reported on echocardiography, but can also be assessed by cardiac magnetic resonance imaging and other modalities.