The Influence of Changes in Preload on Tei index

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.

Thrombolytic Treatment of Prosthetic Valve Thrombosis

BACKGROUND: Prosthetic valve thrombosis is an uncommon but serious complication. Thrombolytic therapy has recently been proposed as an alternative to surgical methods in treating this condition and is used increasingly. However, the indications for thrombolytic treatment in prosthetic valve thrombosis have not been well defined and differential diagnosis of thrombosis is still difficult. METHODS: Four symptomatic patients with prosthetic valve thrombosis underwent 9 thrombolytic sessions for 7 distinct episodes. Transthoracic or transesophageal echocardiography and cinefluoroscopy were performed and repeated after each thrombolytic session. Urokinase or rt-PA (recombinant tissue-type plasminogen activator) was used and repeated dose was given if necessary. Recurrent thrombosis was treated also either with urokinase or rt-PA. RESULTS: All patients were female and mean age was 38.5 years old. Two valves were in mitral position and the other two were in tricuspid position. The anticoagulation status was inadequate in three patients. The initial success after first dose was 43% (3/7), which increased to 54% (4/7) after repeated thrombolytic therapy. Thrombolytic therapy was failed in three episodes; two thromboses and one ingrowths of pannus. Operations were needed in these cases. No complication was seen. CONCLUSION: Thrombolytic treatment can be used as an alternative to surgical therapy with a low risk of complications. But guideline of thrombolytic therapy for the recurrent thrombosis and education for the patients about the adequate anticoagulation were needed.

Post-stress Measurements of Left Ventricular Function With Gated Perfusion SPECT: Comparison with Resting Measurements by using Exercise and Adenosine Stress

BACKGROUND AND OBJECTIVES: This study was designed to investigate the relationship between myocardial perfusion defect in single photon emission tomography(SPECT) and the difference in left ventricular functional parameters obtained after stress and at rest. MATERIALS AND METHODS: Eighty five patients known to have coronary artery disease (CAD) or suspected to have CAD underwent gated Tc-99m sestamibi SPECT using one or separate day rest/stress protocol. We compared post-stress left ventricular ejection fraction (LVEF-s) with that at rest (LVEF-r) in gated myocardial SPECT. We considered myocardial stunning was developed when LVEF was >5% lower than that at rest. METHODS: Forty one (48%) patients demonstrated reversible or irreversible perfusion defects in gated perfusion SPECT (group 1). Forty four (52%) patients demonstrated normal perfusion status (group 2). In group 1, LVEF-s was significantly lower than that at rest([mean+/-SD] 46+/-15.5 vs 48+/-16.0 respectively, p5% lower than LVEF-r. CONCLUSION: The LVEF obtained after stress with gated SPECT may not reflect true resting values. We recommend gated myocardial perfusion SPECT should be performed also at rest especially in patients with myocardial perfusion defects.