Non-invasive assessment of coronary artery stenosis with estimation of myocardial wall stress

More diagnostic techniques require a better understanding of the forces and stresses developed in the wall of the left ventricle. The aim of this study was to differentiate significant coronary artery disease [CAD] patients using a non-invasive quantification of myocardial wall stress in the diastole phase. Sixty male subjects with sinus rhythm [30 patients with significant and 30 with moderate left anterior descending coronary artery stenosis in the proximal portion] as well as 35 healthy subjects as the control group were recruited into the present study. By two-dimensional, pulsed wave, and tissue Doppler echocardiography, the average end-diastolic wall stress was calculated at the left ventricle anterior and interventricular septum wall segments using regional wall thickness, meridional and circumferential radii, and non-invasive left ventricular end-diastolic pressure. A comparison of the calculated end-diastolic myocardial wall stress between the patients with significant and moderate coronary stenosis on the one hand and the healthy subjects on the other showed statistically significant differences in the anterior and septum wall segments [p value < 0.05]. The patients with significant left anterior descending coronary artery stenosis had higher end-diastolic myocardial wall stress than did those with moderate stenosis and the healthy group in all the anterior and septum wall segments. It is concluded that non-invasive end-diastolic myocardial wall stress in coronary artery disease patients is an important index in evaluating myocardial performance

Echocardiographic Characteristics Including Tissue Doppler Imaging After Enhanced External Counterpulsation Therapy

The aim of this study was to echocardiographically assess the effects of EECP [Enhanced External Counterpulsation Therapy] therapy on systolic and diastolic cardiac function. LVEF [left ventricular ejection fraction], ESV [end-systolic volume], EDV [end-diastolic volume], Sm [myocardial systolic wave], Ea [myocardial early diastolic wave], Vp [propagation velocity], E/Ea [peak early diastolic transmitral flow velocity/Ea], E/Vp and diastolic function grade were studied in twenty-five patients before and after 35 hours of EECP. EECP reduced ESV and EDV and increased EF significantly [p=0.018, 0.013, 0.002, respectively] in patients with baseline LVEF 50%. Patients with E/Ea >/= 14 had a significant reduction in EDV and ESV [p=0.038 and 0.32, respectively] and an increase in LVEF [p=0.007] after EECP, whereas patients with baseline E/Ea<14 had no significant change in these parameters. Similarly, EECP significantly improved ESV, EDV and LVEF [p=0.014, 0.032, 0.027 respectively] in patients with grades II and III of diastolic dysfunction [decreased compliance] at baseline, but not in patients with normal diastolic function or grade I diastolic dysfunction [impaired relaxation]. Patients with Ea<7 cm/sec prior to EECP showed significant improvement in EDV, ESV and LVEF after therapy [p=0.024, 0.015, 0.001], while patients with Ea >/= 7cm/sec showed no significant change. Similarly, patients with Sm<7cm/sec prior to EECP showed significant improvement in EDV, ESV and LVEF after EECP [p=0.016, 0.017, 0.006], while patients with Sm >/= 7 cm/sec did not. These results provide new insight into the hemodynamic effectiveness and potential clinical applications of EECP