ABSTRACT
Left ventricular ejection fraction (LVEF) and single-photon emission tomographic (SPET) imaging of the myocardium can be performed after a single technetium-99m sestamibi (MIBI) injection. Sixty patients underwent SPET imaging with MIBI. Immediately after SPET acquisition ECG-gated 99mTc-MIBI perfusion images were acquired using 24 planar images per R-R interval. A new method for measurement of LVEF from the ECG-gated 99mTc-MIBI perfusion images was developed. To validate the method, LVEF derived from MIBI perfusion images was compared with that from conventional radionuclide ventriculography in all 60 patients. Forty patients had evidence of myocardial infarction and 20 had normal perfusion on MIBI imaging. There was no statistically significant difference between LVEF computed from 99mTc-MIBI perfusion images and that from radionuclide ventriculography (r = 0.7062, P < 0.001). There was little difference associated with the technique (intraobserver variability r = 0.9772, P < 0.001). Interobserver variability was also good (r = 0.8233, P < 0.001). LVEF from 99mTc-MIBI perfusion images can be obtained at the same time as assessment of myocardial perfusion and in the same orientation and metabolism of the myocardium, thereby permitting more accurate and realistic prognosis and diagnosis in patients with coronary artery disease.
Subject(s)
Coronary Disease/diagnostic imaging , Gated Blood-Pool Imaging/methods , Heart/diagnostic imaging , Stroke Volume/physiology , Technetium Tc 99m Sestamibi , Tomography, Emission-Computed, Single-Photon/methods , Ventricular Function, Left/physiology , Adult , Aged , Coronary Disease/epidemiology , Female , Humans , Male , Middle Aged , Observer Variation , Prognosis , Reproducibility of ResultsABSTRACT
Obstructive jaundice has been known to cause severe hemodynamic disturbance. The present study was therefore designed to assess the cardiac involvement in jaundiced patients. The multiple-gated blood pool cardioscintigraphic studies were done in 9 jaundiced patients who had either cholestatic or obstructive jaundice (mean total bilirubin 29.30 +/- 3.30 mg/dL), and in 8 normal volunteers (total bilirubin less than 1 mg%). None of the patients had evidences of obvious cirrhosis, intrinisic heart disease, or septicemia. Following intravenous dobutamine there was comparable change of blood pressure and heart rate in both groups. However the response of left ventricular ejection fraction (LVEF) to dobutamine (10 micrograms/kg/min x 5 min) was strikingly blunted in the jaundiced patients as compared to that seen in the normal controls (3.56 +/- 0.9 vs. 12.7 +/- 2.2%, p less than 0.005). Our present data thus show that there is blunted myocardial contractile response to the inotropic stimulation in jaundiced patients. Such myocardial refractoriness to beta-1 stimulation may contribute to the susceptibility of jaundiced patients to postoperative shock and acute renal failure.
