Showing papers by "Alan Rozanski published in 1995"

Using gated technetium-99m-sestamibi SPECT to characterize fixed myocardial defects as infarct or artifact.

Abstract: Perfusion-scan fixed defects may result from soft tissue attenuation, decreasing test specificity for coronary disease and myocardial infarction (MI). Gated 99m Tc-sestamibi SPECT may help differentiate MI from artifact since fixed defects with decreased function (wall motion and thickening) probably represent M1, whereas attenuation affects either have normal function or at least do not demonstrate markedly reduced function. Methods: Ungated resting and gated stress 99m Tc-sestamibi SPECT was performed in 551 consecutive patients referred for evaluation of coronary disease. From resting and summed gated stress images, 180 patients (33%) were identified with isolated fixed defects. Function of the defects was assessed subjectively from gated stress images and results were correlated with clinical (history and/or ECG Q-waves) evidence of MI. Results: Of 102 patients with fixed defects and clinical MI, 98 (96%) had abnormal defect function. Of 78 patients with no clinical MI, 18 (23%) had decreased function of the defect, possibly indicating silent MI. In 60 of the 78 patients (77%) with no clinical MI, defect function was normal. Because most (91 %) of fixed defects with normal systolic function occurred in women with anterior fixed defects (48%) or men with inferior fixed defects (43%), these were most likely attenuation artifacts. By reclassfying patients with fixed defects and normal function as normal, patients with unexplaned fixed defects (no clinical MI) decreased from 14% to 3%. Conclusion: Gating provides a valuable adjunct to 99m Tc-sestamibi SPECT in characterizing fixed defects and potentially improving test specificity. (RESUME N° 90) The association between myocardial sympathetic innervation and heart rate variability after myocardial infarction was studied in a group of 12 men (aged 30-65 yr) 3 mo after their first myocardial infarction. Methods: Viable myocardium was imaged using 123 l-phenylpentadecanoic acid (pPPA). Functioning myocardial sympathetic nervous tissue was imaged using [ 123 I]metaiodobenzylguanidine (MIBG). Heart rate variability was measured as the ratio of maximum-to-minimum RR intervals in ECG during deep breathing. Results: The patients were divided into normal (n = 6) and low (n = 6) heart rate variability groups. Myocardial infarction size (pPPA defect) was comparable in the normal and low heart rate variability groups. Even the MIBG defect size was not significantly different in the normal and low groups, the portion of viable myocardium with impaired sympathetic innervation (MIBG defect minus pPPA defect) was signifiicantly greater in the low heart rate variability group than in the normal group. Conclusion: The extent of viable myocardium with disturbed sympathetic innervation was greater in patients with low heart rate variability as compared to those with normal heart rate variability 3 mo after myocardial infarction

The limited efficacy of exercise radionuclide ventriculography in assessing prognosis of women with coronary artery disease

Abstract: Increasing numbers of women are undergoing stress testing for coronary artery disease evaluation. Limited study is available as to its efficacy in women. Four hundred nineteen patients with coronary artery disease (74 women and 345 men) referred for exercise radionuclide ventriculography between 1979 and 1986 were evaluated in a prospective cohort evaluation with 5-year follow-up. Exercise radionuclide ventriculographic variables were analyzed and compared between women and men. The prognostic efficacy of exercise radionuclide ventriculography was assessed separately for women and men among patients with coronary artery disease by Kaplan-Meier cumulative survival curves, univariate Cox regression analyses, and hierarchical stepwise Cox regression analyses. Overall, women demonstrated higher resting and peak left ventricular ejection fraction response to exercise than men. Ninety-six of 419 patients (23%) had cardiac events at 5-year follow-up. Although left ventricular response to exercise conveyed prognostic information in the combined and male populations (multivariate hierarchical analyses chi-square 11, p = 0.001 for delta left ventricular ejection fraction and chi-square 10, p = 0.002 for worsening exercise wall motion score), these variables were not found to be prognostically useful in women. Women with coronary artery disease demonstrated a worsened functional status, evidenced by greater compromise of exercise capacity, despite having less extensive anatomic disease than their male counterparts. We conclude that sex-related differences in left ventricular response to exercise limit the prognostic utility of exercise ventriculography in women with coronary artery disease.