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Electrical waves track a systole (a contraction) of the heart. The end-point of the P wave depolarization is the start-point of the atrial stage of systole. The ventricular stage of systole begins at the R peak of the QRS wave complex; the T wave indicates the end of ventricular contraction, after which ventricular relaxation (ventricular diastole) begins.
It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole. [1] After emptying, the heart relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body, before again ...
Diastole (/ d aɪ ˈ æ s t ə l i / dy-AST-ə-lee) is the relaxed phase of the cardiac cycle when the chambers of the heart are refilling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricular diastole the relaxing of the ventricles.
The period of time that begins with contraction of the atria and ends with ventricular relaxation is known as the cardiac cycle. The period of contraction that the heart undergoes while it pumps blood into circulation is called systole. The period of relaxation that occurs as the chambers fill with blood is called diastole.
The period of time during which the ventricles contract, forcing blood out into the aorta and main pulmonary artery, is known as systole, while the period during which the ventricles relax and refill with blood is known as diastole. The atria and ventricles work in concert, so in systole when the ventricles are contracting, the atria are ...
The isovolumetric contraction phase lasts about 0.05 seconds, [1] but this short period of time is enough to build up a sufficiently high pressure that eventually overcomes that of the aorta and the pulmonary artery upon opening of the semilunar valves. This process, therefore, helps maintain the correct unidirectional flow of blood through the ...
A Wiggers diagram modified from [1]. A Wiggers diagram, named after its developer, Carl Wiggers, is a unique diagram that has been used in teaching cardiac physiology for more than a century.
Cardiac output (= heart rate * stroke volume. Can also be calculated with Fick principle, palpating method.) Stroke volume (= end-diastolic volume − end-systolic volume) Ejection fraction (= stroke volume / end-diastolic volume) Cardiac output is mathematically ` to systole [clarification needed] Inotropic, chronotropic, and dromotropic states