ABSTRACT
Objective To study the hemodynamics during closed chest cardiopulmonary resuscitation (CCCPR) in dogs in order to unravel the mechanism. Method Twelve healthy mongrel dogs were selected to make animal model of ventricular fibrillation induced by electric shock on the chest wall. Closed-chest cardiopulmonary resuscitation (CCCPR) was initiated four minutes after ventricular fibrillation appeared according to American Heart Guidelines in 2005 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Rescue. After CPR for 2 minutes, 1mg epinephrine was injected intravenously. The central venous pressure (CVP), the aortic pressure (AOP)and the invasive electrocardiogram (ECG) were used to monitor continuously before ventricular fibrillation and the entire course of CPR. The coronary perfusion pressure (CPP) was calculated. The changes in aortic diastolic pressure (ADP) and CPP produced by chest compression or the injection of epinephrine were analyzed. The aortic pressure and the central venous pressure were recorded simultaneously during CPR. A chart was made and the CPP was calculated with the software Chart5Ch. The hemodynamic changes produced by the administration of epinephrine were studied. Data were analyzed with paired Student t test. P ＜ 0.05 was considered as a significant difference. Results Two kinds of hemodynamic effects of CPR were observed. In 8 dogs (8/12) , the aortic pressure changed synchronously with the CVP, and the CPP was almost zero, and in other 4 dogs (4/12), the aortic pressure increased and the CVP remained unchanged with presence of the CPP. After the administration of epinephrine, the AOP and the CPP increased significantly. The Aortic systolic pressure(ASP) increased from (66± 14) mmHg to(107 ± 28) mmHg, (P = 0. 001). The Aortic diastolic pressure (ADP) increased from (25 ±2.2) mmHg to(45 ± 13) mmHg (P =0.001). And the coronary perfusion pressure (CPP) increased from (2.8± 3.8) mmHg to (29 ± 13) mmHg (P ＜ 0.001). The 95 % confidential interval of the added value of the ASP,ADP and CPPwere (21.1-59.1), (10.2-28.3) and (16.7-35.7), respectively. Conclusions The thoracic pump mechanism is the primary role in the closed chest Cardiopulmonary resuscitation. Epinephrine can increase ADP and CPP and has the capability to break the balance between aortic pressure and central venous pressure, increasing the rate of successful cardiopulmonary resuscitation.
ABSTRACT
Objective To investigate the left ventricular function changes of dobutamine stress echocardiography(DSE) in the patients with chest pain.Methods The left ventricular systolic and diastolic function of patients was evaluated using two-dimensional and pulse Doppler echocardiography by DSE.Results After DSE,among the 18 patients,8 appeared abnormal regional motion in the wall of left ventricle and 10 were normal.The SV and CO of those remained normal were higher than those who appeared abnormal.For both normal and abnormal patients the E/A ration was smaller than 1 when dobutamine was at peak dose.Conclusion Using DSE on chest pain patients was an effective method in evaluating regional and global systolic function of the left ventricle and the effective detection data for left ventricular diastolic function is still to be determined.