Objectives The study purpose is to investigate the value of pulse wave tissue Doppler imaging (PW-TDI) in evaluating right ventricular systolic function of patients with pulmonary hypertension.
Methods 78 patients with pulmonary hypertension were divided into 3 groups according to the level of pulmonary artery systolic pressure (PASP) . Mild PH group: 31 cases, 35 mmHg ≤ PASP < 50 mmHg, Moderate PH group: 25 cases, 50 mmHg ≤ PASP <70 mmHg, Severe PH group: 22 cases, PASP ≥ 70 mmHg. All the patients were classified to 4 grades according to WHO classification of right ventricular function of patients with pulmonary hypertension, ClassI9 patients, ClassII 28 patients, ClassIII 29 patients, ClassIV 12 patients. Patients with severe irregular heart rhythm such as atrium fibrillation, abnormal left ventricular systolic function were all excluded. Control group included 46 healthy individuals determined by the clinical characters, CR, electrocardiogram and echocardiography.
Echocardiography was performed using a commercially available ultrasound system (GE Vivid7.0) and a 1.7∼3.4 MHz phased-array transducer. In standard apical 4-chamber view, Tran tricuspid and pulmonary flows were recorded by pulse wave Doppler echocardiography. The related time intervals were measured, to calculate right ventricular Tei index. According to tricuspid regurgitate jet, PASP was calculated as the sum of the Trans-tricuspid gradient and the estimated RA pressure. PW-TDI was performed using spectral pulsed Doppler signal filters. In the apical 4-chamber view, tricuspid annulus motion curve was recorded and was used to calculate right ventricular Tei index, isovolumetric acceleration (IVA) and peak systolic velocity (Sv).
Results Right ventricular Tei index derived from PW-TDI were significantly increased in patients with PH. Significant differences were noted between any two groups (P<0.05). IVA, and Sv in the moderate and severe PH groups were significantly lower than those of the control and mild PH group (P<0.01). But there is no difference between mild PH and control group or moderate and severe PH group, respectively. When a cut off value of 0.45 of right ventricular Tei index derived from PW-TDI was used to detect the degree of right ventricular function of PH>ClassII, the sensitivity and specificity was 82.6%and 90.9%, respectively.
Conclusions The right ventricular Tei index derived by PW-TDI is more sensitive and earlier to detect impairment of the right ventricular function in the patients with PH. When a cut off value of 0.45 of right ventricular Tei index derived from PW-TDI was used to detect the class of right ventricular function of PH>ClassII, the sensitivity and specificity were both excellent.. Sv and IVA derived from the tricuspid annular by TDI can be used to estimate the right ventricular longitudes systolic function.