ABSTRACT
Objective To analyze the correlation between the pressure volume parameters and cardiac function in terms of New York Heart Association(NYHA) classification in patients with pulmonary arterial hypertension. Methods Among 36 patients with pulmonary hypertension admitted in our center between April 2015 to June 2016, right heart catheterization recording right atrial pressure curve,right ventricular pressure curve,pulmonary arterial pressure and oxygen saturation curve in different parts was performal.All patients recived underwent cardiac MRI examination to obtain a single cardiac cycle and the use of Mass software to measure right ventricular volume continuously and right ventricular pressure-volume loop parameters were then obtained. Patients were divided into different groups according to the NYHA functional classification, and the correlation between the parameters of each group and the cardiac function classes a were analyzed. Results Compare to patients with NYHA class Ⅰheart function,patients with NYHA heart function class Ⅱ and class Ⅲ had significantly higher right ventricular end diastolic pressure(P < 0.05)and higher right ventricular systolic pressure (P < 0.01). Spearman correlation analysis showed that cardiac function of NYHA classⅠ,Ⅱ and Ⅲhad position correlation with RVESV,RVEDP and RVESP wheras negative correlation with RVEDV. ROC curve analysis showed that,when the patients were divided into 2 groups as NYHAⅠvs. NYHA class Ⅱ + Ⅲ,NYHA classification for predicting the outcome of the NYHA class Ⅱ + Ⅲ level, pulmonary artery elasticity and right ventricular end systolic pressure had larger area under curves respectively. Conclusions Pressure-volume parameters of right ventricles are more objective indicators for cardiac function assessment for pulmonary hypertension patients and evaluation of disease progression especialy in patients with mild symptoms.
ABSTRACT
Objective To analyze the correlation between the pressure volume parameters and cardiac function in terms of New York Heart Association(NYHA) classification in patients with pulmonary arterial hypertension. Methods Among 36 patients with pulmonary hypertension admitted in our center between April 2015 to June 2016, right heart catheterization recording right atrial pressure curve,right ventricular pressure curve,pulmonary arterial pressure and oxygen saturation curve in different parts was performal.All patients recived underwent cardiac MRI examination to obtain a single cardiac cycle and the use of Mass software to measure right ventricular volume continuously and right ventricular pressure-volume loop parameters were then obtained. Patients were divided into different groups according to the NYHA functional classification, and the correlation between the parameters of each group and the cardiac function classes a were analyzed. Results Compare to patients with NYHA class Ⅰheart function,patients with NYHA heart function class Ⅱ and class Ⅲ had significantly higher right ventricular end diastolic pressure(P < 0.05)and higher right ventricular systolic pressure (P < 0.01). Spearman correlation analysis showed that cardiac function of NYHA classⅠ,Ⅱ and Ⅲhad position correlation with RVESV,RVEDP and RVESP wheras negative correlation with RVEDV. ROC curve analysis showed that,when the patients were divided into 2 groups as NYHAⅠvs. NYHA class Ⅱ + Ⅲ,NYHA classification for predicting the outcome of the NYHA class Ⅱ + Ⅲ level, pulmonary artery elasticity and right ventricular end systolic pressure had larger area under curves respectively. Conclusions Pressure-volume parameters of right ventricles are more objective indicators for cardiac function assessment for pulmonary hypertension patients and evaluation of disease progression especialy in patients with mild symptoms.
ABSTRACT
Objective To obtain pressure-volume relatioship for the rabbit eye in vivo. Method Physiological salt solution was injected with the rate of 20 μL/min through the limbus to the anterior chamber of the rabbit eye for 100 min and the intraocular pressure (IOP) was recorded. Results The relationship between IOP and injection time could be fitted to a segmented function with a characteristic point called IOPg. The ocular rigidity coefficients before and after this IOPg were (4.02±0.86) mmH2O/μL and (2.43±0.94) mmH2O/μL, respectively (1 mmH2O=9.8 Pa), showing significant difference. Conclusions IOPg existed in all curves of IOP and injection time and the ocular rigidity coefficients were dependent on the injection rate and position of IOPg. Parameters of the fit function between IOP and injection time have definite physiological significance.
ABSTRACT
<B>Purpose</B><br> We assessed the effect of Electroacupuncture (EA) at Zusanli (ST36) acupoint on cardiac perfor-mance of spontaneously hypertensive rat (SHR), analyzing left ventricular pressure-volume (PV) relationship.<br><b>Methods</b><br> SHR and Wistar-Kyoto rat (WKY) were anesthetized with isoflurane (1%). Conductance catheter (SPR-838, Millar instruments, Houston, Texas) was inserted into left ventricle via carotid artery. Steady state was maintained for at least 5 min before EA was started. <br> EA stimulation point was set on the right anterior side of hindlimb, corresponding to Zusanli (ST36) acupoint in humans. SHR and WKY underwent EA stimulation in a frequency of 2Hz and intensity of 6mA with a pulse generator (Han’s Healthronics Likon,Taipei, Taiwan) for 15 min. PV relationship was measured at baseline, 10min after the start of EA stimulation and at 0, 5, 10, 15 min after the end, then analyzed to obtain parameters for cardiac performance.<br><b>Result</b><br> In the basic state before EA stimulation, ESP, SW, PVA, Ea, dp/dtmax, dp/dtmin, Pmax, ESPVR and EDPVR in SHR was significantly higher than those in WKY(ESP, 109.6±8.3 vs. 175.0±14.6mmHg, p<0.01 ; SW, 5.7±1.6 vs. 8.8±3.7mmHg·ml, p<0.05 ; PVA, 11.7±4.0 vs. 19.3±6.4mmHg· ml, p<0.01 ; Ea, 1804.2±382.4 vs. 2625.3±629.3 mmHg/ml, p<0.01 ; dp/dtmax, 7512.9±1628.8 vs. 13406.3±1771.4mmHg/s, p<0.01 ; dp/dtmin, -7159.7±1236.8 vs. -12082.5±1280.2 mmHg/s, p<0.01 ; Pmax, 116.7±6.8 vs. 176.8±14.6mmHg, p<0.01 ; ESPVR, 1013.8±320.3 vs. 1520.1±494.8mmHg/ml, p<0.05 ; EDPVR 70.0±39.3 vs. 178.3±130.2 mmHg/ml, p<0.05, respectively), indicating increased systolic function and decreased diastolic function in SHR.<br> Significant change in parameters of WKY could not be observed after EA stimulation.In SHR, ESP, EDP, Ea, dp/dtmax, dp/dtmin, Pmax was significantly decreased at 10 min after EA started. ESPVR was not significantly affected by EA in both WKY and SHR, however, ESPVR tended to be increased in WKY and decreased in SHR at 10min after the start of EA stimulation.<br><b>Conclusion</b><br> EA decreased indicators of systolic function in SHR that is significantly higher than WKY. This study suggests that EA improved enhanced systolic function in SHR, compared with WKY.