[Physiopathology of cardio-circulatory accidents].

The cardio-circulatory system is a transportation system which allows the oxygen to be brought to the organs and eliminates the carbon dioxide produced by these organs. It includes the heart and the vessels. The quantity of blood pulsed by the heart is called cardiac output (approximately 51/mn for an adult). When the needs in oxygen increase (exercise), the cardiac output increases. That increase is mostly related to an increase of the cardiac frequency (tachycardia). The vessels oppose a certain resistance to the blood flow. An inverse relation exist between cardiac output and vascularly resistance: physiologically, when one increases the other decreases and reciprocally. The mechanism and the symptomatology of cardio-circulatory accidents can be explained by alterations of the cardiac output and/or the vascularly resistances.