Definition

1. Noun:
   • The complete sequence of mechanical and electrical events in the heart from the start of one heartbeat to the start of the next. This includes the phases of contraction (systole) and relaxation (diastole) of the heart chambers, which pump blood through the circulatory system.

Usage

• The term "cardiac cycle" is used in medical, physiological, and biological contexts to describe the rhythmic, repeating pattern of the heart's activity.
• It is typically discussed as a single, measurable unit of heart function.

Examples

• Noun:
  • Understanding the cardiac cycle is fundamental to cardiology.
  • The duration of a single cardiac cycle decreases when the heart rate increases.
  • The professor explained how pressure changes in the chambers correspond to different phases of the cardiac cycle.

Advanced Usage

• "to analyze the cardiac cycle": to examine the detailed events and timing of the heart's phases.
  • Researchers use advanced imaging to analyze the cardiac cycle in real-time.
• "phases of the cardiac cycle": the specific stages, such as atrial systole, ventricular systole, and diastole.
  • The diagram clearly labeled all four main phases of the cardiac cycle.

Variants and Related Words

• Cardiac (adj): relating to the heart.
  • Cardiac muscle is unique to the heart.
• Cycle (n): a series of events that are regularly repeated in the same order.
  • The sleep cycle consists of several stages.
• Systole (n): the phase of the cardiac cycle when the heart muscle contracts.
• Diastole (n): the phase of the cardiac cycle when the heart muscle relaxes and fills with blood.

Synonyms

• Heart cycle: A less common but direct synonym.
• Cardiac sequence: Emphasizes the ordered series of events.

Related Phrases

• Cardiac output: The volume of blood the heart pumps per minute, directly influenced by the cardiac cycle.
• Electrocardiogram (ECG/EKG): A test that records the electrical activity of the heart throughout the cardiac cycle.

Noun

1. the complete cycle of events in the heart from the beginning of one heart beat to the beginning of the next; an electrical impulse conducted through the heart muscle that constricts the atria which is followed by constriction of the ventricles
   • the cardiac cycle can be shown on an electrocardiogram