The Influence of Changes in Preload on Tei index

ABSTRACT

BACKGROUND: Tei index is a Doppler-derived index of combined systolic and diastolic myocardial performance proposed to be a promising noninvasive measurement of overall cardiac function, calculated as the sum of isovolumic contraction (ICT) and isovolumic relaxation times (IRT) divided by ejection time (ET). This study aimed to investigate the effect of changes in preload on Tei index. SUBJECTS AND METHOD: The study population was 10 patients with chronic renal failure who are on regular hemodialysis (HD). They were 3 men and 7 women with a mean age of 45.3+/-12.4 years old. The complete 2-dimensional and Doppler echocardiography including recordings of mitral inflow and left ventricular outflow were performed using HP SONOS 1500 equipment before and after HD. Body weight was measured using electric scale before and after HD. Blood pressure and pulse rate were measured by an automated cuff measurement every 1 hour throughout HD. Hematocrit was monitored noninvasively and continuously using the Crit-Line instrument (In-Line Diagnostics, Riverdale, UT, USA) during HD. RESULTS: There were no significant changes in systolic and diastolic blood pressure, RR interval, left ventricular end-diastolic and end-systolic dimension, left atrial dimension, and left ventricular ejection fraction during HD. The mean body weight loss during HD was 2.1+/-0.65 kg. The percentage of reduction of body weight was 4.1+/-1.56%. Changes in total blood volume at the end of HD were compared with that of baseline -11.79+/-5.51%. The percent change in total blood volume during the HD correlated significantly with the amount of change in body weight (r=0.678, p<0.05) and percent change in body weight (r=0.835, p<0.01), respectively. ICT before HD and at the end of HD were 39+/-13.0, 42+/-24.1 msec (p=NS). IRT before HD and at the end of HD were 76+/-29.1, 95+/-28.5 msec (p<0.01) and , ET before HD and at the end of HD were 317+/-18.1, 289+/-9.0 msec (p<0.01), respectively. Tei index before HD was 0.36+/-0.10, and the index at the end of HD were 0.47+/-0.13 (p<0.001). CONCLUSION: When there is a change in preload during a short period, it seems that the effect of change in preload should be considered when using Tei index to assess ventricular function.