Assessment of Right Ventricular Function in Patients with Chronic Obstructive Pulmonary Disease Using Echocardiographic Tei Index

Oh, Yoon Jung; Shin, Joon Han; Kim, Deog Ki; Choi, Young Hwa; Park, Kwang Joo; Hwang, Sung Chul; Lee, Yi Hyeong

Abstract

BACKGROUND
Advanced chronic obstructive pulmonary disease is characterized by progressive pulmonary hypertension leading to right heart dysfunction, which plays a important role in clinical evaluation but remains difficult and challenging to quantify. The noninvasive doppler echocardiographic value referred to as the Tei index has been suggested as a simple, reproducible and reliable parameter of the right ventricular function. The purpose of this was to assess the right ventricular function in patients with chronic obstructive pulmonary disease using the Tei index and to evaluate its relationship with the pulmonary functional status.
METHODS
The study population comprised of 26 patients with chronic obstructive pulmonary disease and 10 normal control subjects. The Tei index was obtained by dividing the sum of the isovolumetric contraction and the relaxation tines by the ejection time using a pulsed-wave doppler. It was compared with the other available Doppler echocardiographic parameters of systolic or diastolic and with the pulmonary function of the patients.
RESULTS
The Tei indices of the patients with COPD were significantly higher than those of normal subjects (0.45±0.17 vs. 0.27±0.03, p<0.01). The isovolumetric contraction time/ejection time(0.32±0.08 vs. 0.25±0.05, p<0.05), the isovolumetric relaxation time/ejection time(0.29±0.16 vs. 0.15±0.08, p<0.05) and the preejection period/ejection time (0.46±0.10 vs. 0.38±0.06, p<0.05) were prolonged and the ejection time (255.2±32.6 vs. 314.2±16.5 msec, p<0.05) was significantly shortened in patients with COPD compared to normal subjects. The tei indices were inversely correlated with the FEV1(r=-0.46, p=<0.05) and were prolonged significantly in patients with a severe obstructive ventilatory dysfunction(less than 35% of predicted FEV1) compared to those with a mild and moderate ventilatory dysfunction. The tei indices showed an inverse correlation with the ejection time (r=-0.469), the isovolumetric contraction time/ejection time(r=0.453), the isovolumetric relaxation time/ejection time(r=0.896) and the preejection period/ejection time(r=0.480).
CONCLUSION
The tei index appeared to be a useful noninvasive means of evaluating the right ventricular function. It revealed a significant correlation with the pulmonary function in patients with COPD.