️ Cardiovascular System – Cardiac Cycle & Cardiac Output

Cardiac Cycle

,Cardiac Cycle
• Cardiac cycle is the mechanical sequence of events
as blood enters the atria and leaves the ventricles



• The events includes:
Atrial events

Ventricular events

, DIVISIONS AND DURATION
OF CARDIAC CYCLE
• When the heart beats at a normal rate of 72/minute, duration
of each cardiac cycle is about 0.8 second

• „ ATRIAL EVENTS
• Atrial events are divided into two divisions:
• 1. Atrial systole = 0.11 (0.1) sec
• 2. Atrial diastole = 0.69 (0.7) sec.
„
• VENTRICULAR EVENTS
• Ventricular events are divided into two divisions:
• 1. Ventricular systole = 0.27 (0.3) sec
• 2. Ventricular diastole = 0.53 (0.5) sec.