The Cardiac Cycle

The pathway of the electrical impulses can best be seen by looking in detail at a single heart cycle. The period from the beginning of one heartbeat to the next is called the cardiac cycle. The cardiac cycle consists of a period of contraction, called systole, followed by a period of relaxation, called diastole. During the diastole phase, your heart relaxes and allows blood to flow into the two ventricles; during the systole phase, the ventricles contract, driving blood to the lungs and throughout the body. In a healthy, resting adult, the heart beats about 60 to 80 times a minute, so that the cardiac cycle lasts only about .8 seconds.

Click here to see the Cardiac Cycle.

Last updated December 02, 2011

Printer-friendly format

1996-2013. Aetna Inc. All rights reserved. All information is intended for your general knowledge only and is not a substitute for medical advice or treatment for specific medical conditions. You should seek prompt medical care for any specific health issues and consult your physician before starting a new fitness regimen. Use of this online service is subject to the disclaimer and the terms and conditions. External website links provided on this site are meant for convenience and for informational purposes only; they do not constitute an endorsement. These external links open in a different window. The Aetna InteliHealth website subscribes to the HONcode principles of the Health On the Net Foundation. "InteliHealth" and "The Trusted Source" are trademarks of Aetna Inc.

•	Complementary & Alternative Medicine
•	Fitness
•	Nutrition
•	Weight Management
•	Workplace Health

•	Children's Health
•	Men's Health
•	Seniors' Health
•	Women's Health
•	More

•	Medical Dictionary
•	Diseases and Conditions
•	Drug Resource Center
•	More

•	Addiction
•	Allergy
•	Alzheimer's Disease
•	Anemia
•	Arthritis
•	Asthma
•	Breast Cancer
•	Cancer
•	Cholesterol
•	Chronic Obstructive Pulmonary Disease
•	Chronic Pain
•	Dementia
•	Depression
•	Diabetes
•	Digestive
•	Digestive-Tract Cancer
•	Ear, Nose And Throat Disorders
•	Epilepsy
•	Eyes
•	Feet
•	Glaucoma
•	HIV/AIDS
•	Hair Loss
•	Headache
•	Heart and Circulatory
•	High Blood Pressure
•	Impotence
•	Infertility
•	Kidney Disease
•	Low Back Pain
•	Lyme Disease
•	Memory Loss
•	Mental Health
•	Multiple Sclerosis
•	Osteoarthritis
•	Pregnancy
•	Prostate Cancer
•	Rheumatoid Arthritis
•	Sexual And Reproductive Health
•	Sexually Transmitted Diseases
•	Skin Cancer
•	Sleep
•	Stress
•	Stroke
•	Weight Management