ABSTRACT
AIM: To analyze and compare the changes of pressure phase plane(PPP) derived τ and K on isolated rat heart during ischemia/reperfusion, and to explore the value of PPP derived τ and K for evaluation of left ventricular diastolic dysfunction. METHODS: LVEDP, -d(p/dt)_(max), τ and K were measured and calculated during ischemia/reperfusion in Sprague-Dawley rat hearts. Meanwhile, the level of lactate dehydrogenase (LDH) in the coronary effluent was measured, and the ultrastructure changes in myocardium were observed under electron microscope. RESULTS: Compared with control group, τ increased and K reduced significantly in each ischemic group in a time dependent manner (P<0.05). With prolonged ischemia, τ was even higher and K was even lower (P<0.05). Compared with control group, except ischemia 15 min, LDH in other groups increased significantly at 10 min and 20 min after reperfusion (P<0.05). Compared with ischemia 30 min, LDH of ischemia 45 min and ischemia 60 min were even higher at 10 min and 20 min after reperfusion (P<0.05). With prolonged ischemia, the abnormal changes of the myocardial ultrastructure were observed. CONCLUSION: PPP derived τ and K may be promising indexes for quantitative assessment of left ventricular diastolic function on isolated) rat heart during ischemia/reperfusion, and indication of the severity of ischemia/reperfusion injury.
ABSTRACT
Objective To establish the method of depict ing the left ventricular (LV) pressure-volume loop automatically by computer which incorporates LV catherization simultaneous with LV acoustic quantification echocardiography and to assess echocardiography non-invasive evaluation LV chamber stiffness. Methods Thirteen patients with hypertrophic cardiomyopathy (HCM) underwent LV catherization simultaneously with echocardiography. LV pressure and volume curves were sent to computer, and LV pressure-volume loop was depicted automatically and modulus of LV chamber stiffness (Kc) was obtained. Pulsed Doppler echocardiography of mitral intraventricular flows was obtained in patients with HCM. Results Patients with HCM had significantly higher Kc obtained from LV pressure-volume loop ( 0.43 ? 0.11 vs 0.27 ). R-E 3/R-E 0, (R-E 2)-(R-E 1), (R-A 3)-(R-A 2) were correlated to Kc(r= 0.61 , 0.57 , 0.58 ,respectively). Conclusions This method provides a simple and reliable technique for automatically tracing pressure-volume loop and should facilitate further investigation of the left ventricular diastolic function in clinical practice. R-E 3/ R-E 0, (R-E 2)-(R-E 1), (R-A 3)-(R-A 2) offer new non-invasive indices in evaluating LV chamber stiffness.