Low blood pressure can hamper the cardiac output too. Cardiac output is defined as the volume of blood ejected from the right or left ventricle into the aorta or pulmonary trunk per minute. There are two major factors that are responsible for the cardiac output (Rais-Bahrami, Majd, Veszelovszky, Short, 2004). They are stroke volume and heart rate.
Cardiac output= Heart rate * Stroke volume
The average heart beats in one minute is 75 beats per minute in an adult. Stroke volume is the amount of blood pumped by each ventricle with each heartbeat which is average 70 ml per beat in an adult body (Sadava, David, Heller, Craig; Orians, Gordon, 2006). In the case, as Mr. Underhill has low blood pressure, the blood circulation is affected and the stroke volume should not be normal. The heart beats are also affected by the low blood pressure. In the case, the cardiac output will also be lower than normal person which can lead to death sometime. The main function of heart is to transport blood in order to deliver various nutrients, oxygen and other chemicals to the numerous cells of the body in order to ensure the proper function of the body. The heart also removes cellular wastes. As the heart is considered as a demand pump, it pumps out the amount of blood comes into it from venous system. The amount of blood returned to the heart determines the amount of blood heart pumps out. In the case, Mr. and Mrs. Underhill had been suffered from dehydration which might resulted in improper blood circulation in heart.
血压低会妨碍心输出量。心输出量被定义为右心室或左心室排出的血液量为每分钟进入主动脉或肺动脉干。有两个主要因素负责的心输出量（RAIS巴赫拉米，玛依德，Veszelovszky，短发，2004年）。他们的每搏输出量和心脏速率。
心输出量=心率*每搏输出量
平均在一分钟内心脏跳动每分钟75次，在成人。每搏输出量的血液量，这是平均70毫升，每拍一个成年的的身体（Sadava，大卫海勒，克雷格Orians，戈登，2006年），每次心跳泵各脑室。昂德希尔先生的情况下，有血压低，血液循环的影响，每搏输出量不应该是正常的。心脏跳动也受到低血压。的情况下，心输出量也将是低于正常人一段时间可导致死亡。心脏的主要功能是输送血液，以提供各种营养，氧气和其他化学品，众多的人体细胞，以保证身体的正常功能。心也消除体内废物。的心脏被认为是一个需求泵，泵出的血液量，从静脉系统。返回到心脏的血液量确定的量的血液的心脏泵出。先生和夫人昂德希尔的情况下，已出现脱水，这可能会导致心脏的血液循环不当。
