| Heart failure(HF) is the terminal stage of various heart diseases and is the leading cause of death in cardiovascular disease. According to statistics, there are about 4 million patients with heart failure in 35 ~ 74 years old adults in our country. The readmission rate of patients with heart failure within 3 ~ 6 months is 27% ~ 50% and 1 year all-cause mortality is 30%. Heart failure in a serious threat to human health and life safety and it has been regarded as one of the most serious public health problems in the 21 st century.Previous studies suggested that lungs and heart are not only adjacent, but their functions are closely related and influence each other. Pulmonary circulation is the main place of gas exchange with outside environment. At the same time, it is also effective in accommodating blood. The total area of lung capillary is equivalent to 90% of the alveolar area. The alveolar area of adult is approximately 60m2 at rest, and increasing to 90m2 with exercise. The blood volume of pulmonary capillary is less than 100 ml at rest, and it can increase to 150~250ml with exercise. Pulmonary capillary can degrade the pressure from pulmonary artery to left atrial and accommodate blood because it is density, thick and stretchy.This study caused pulmonary vascular bed volume differences of New Zealand white rabbits through ligatured the pulmonary lobes.Used impedance cardiography and impedance pulmonary rheogram technologies to compare the progress of left cardiac insufficiency caused by ligatured the ascending aorta. Aimed to investigate that whether pulmonary had accommodate blood function and whether its differences influenced the progress of left cardiac insufficiency and to provide a theoretical basis for the prevention and cure of heart failure.30 healthy, grown, male New Zealand white rabbits were randomly divided into control group and experiment group. Used the WA-820 digital impedance rheograph to record the impedance cardiography and impedance pulmonary rheogram of the two groups after made models. Recorded heart rate(HR), left ventricular end-diastolic pressure(LVEDP), stroke volume(SV), stroke work(SW), left ventricular ejection fraction(LVEF), height of right ventricular systolic wave(HS), height of ventricular diastolic wave(HD), rapid ejection time of right ventricular(RET), right heart failure index(RHFI), myocardial strain index(MSI), mean pulmonary arterial pressure and compared them(mPAP). Ligatured the ascending aortas of the two groups, then used the WA-820 digital impedance rheograph to record the impedance cardiography every 20 minutes. Recorded HR, LVEDP, SV, SW, LVEF and other indexes of two groups until the rabbits appeared obvious heart function change.Compared with the control group, HR, LVEDP of the experiment group increased slightly, SV, SW, LVEF reduced slightly, but the changes were not obvious(P > 0.05). Compared with control group, HS, HD, RET, RHFI of the experiment group were obviously reduced. MSI, mPAP were obviously increased(P < 0.05). Compared with ligatured the ascending aortas ago, HR, LVEDP of the experiment group increased obviously, SV, SW, LVEF decreased obviously 20 minutes later(P < 0.05). The control group appeared above changes 60 minutes later(P < 0.05).The study results showed that reduced pulmonary blood volume led to pulmonary circulation and right heart function damage, but had no directly effect on hemodynamic of left heart. Pulmonary had accommodate blood function and its differences influenced the progress of left cardiac insufficiency. |
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