Definition

1. Noun:
   • The phase of the cardiac cycle during which the heart muscle contracts: Specifically, systole refers to the contraction of the heart's chambers, primarily the ventricles, to pump blood out into the major arteries (the aorta and pulmonary artery). It is the active, pumping phase of the heartbeat.

Usage Examples

• Noun:
  • Ventricular systole is essential for pumping oxygenated blood to the body.
  • The doctor measured the duration of systole and diastole on the patient's echocardiogram.
  • Blood pressure readings reflect the pressure during cardiac systole and diastole.

Advanced Usage

• "Atrial systole": The contraction of the atria, which occurs just before ventricular systole and helps complete the filling of the ventricles.
  • Atrial systole contributes the final 20-30% of ventricular filling.
• "Electrical systole": The duration of the electrical activity (seen on an ECG as the QRS complex and T wave) that triggers mechanical contraction.
  • The QT interval on an ECG approximates the duration of electrical systole.

Variants and Related Words

• Systolic (adj): Pertaining to or occurring during systole.
  • Systolic blood pressure is the higher number in a blood pressure reading.
• Asystole (n): The absence of cardiac contractions; cardiac arrest.
  • The patient's ECG showed a flat line, indicating asystole.

Synonyms

• Contraction phase: The period of heart muscle contraction.
• Ejection phase: The part of the cardiac cycle when blood is ejected from the heart.

Antonyms

• Diastole (n): The phase of the cardiac cycle when the heart muscle relaxes and the chambers fill with blood.
  • Coronary arteries are primarily perfused with blood during diastole.

Noun

1. the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery