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This process is of vital importance as it allows for the heart to beat in a controlled manner, without the need for conscious input. EC coupling results in the sequential contraction of the heart muscles that allows blood to be pumped, first to the lungs ( pulmonary circulation ) and then around the rest of the body ( systemic circulation ) at ...
Clinical death is the medical term for cessation of blood circulation and breathing, the two criteria necessary to sustain the lives of human beings and of many other organisms. [1] It occurs when the heart stops beating in a regular rhythm, a condition called cardiac arrest. The term is also sometimes used in resuscitation research.
In 2021, the American Heart Association clarified that "heart attack" is often mistakenly used to describe cardiac arrest. While a heart attack refers to death of heart muscle tissue as a result of blood supply loss, cardiac arrest is caused when the heart's electrical system malfunctions. Furthermore, the American Heart Association explains ...
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. [1] 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]
Considering that the total cardiac cycle has a duration of one second (for a base heart rate of 60 beats per minute), the probability of impact trauma within the window of vulnerability is 1–3 percent only. [1] The cellular mechanisms of commotio cordis are not fully understood. However, it is widely recognized that it may be related to the ...
Continued pumping operation of the heart during exsanguination increases the rate of depletion and thus hastens death by raising the fluid pressure of the blood. Because the heart operates like a positive displacement pump , blood volume reduction will not affect cardiac output efficiency.
The heart and lungs are vital organs for human life due to their ability to properly oxygenate human blood (lungs) and distribute this blood to all vital organs (heart). Hence, failure of the heart to pump blood or the lungs to obtain oxygen can lead to a cardiopulmonary death where the heart stops pumping and there is no pulse.
The pumping action of the heart generates pulsatile blood flow, which is conducted into the arteries, across the micro-circulation and eventually, back via the venous system to the heart. During each heartbeat, systemic arterial blood pressure varies between a maximum and a minimum pressure. [33] In physiology, these are often simplified into ...