Normal Myocardial Scan Research Articles

Influence of coronary artery disease assessment and treatment in the incidence of cardiac events in renal transplant recipients

The best strategy for pre-transplant investigation and treatment of coronary artery disease (CAD) is controversial. We evaluated 167 renal transplant recipients before transplantation to determine the incidence of cardiac events and death. We performed clinical evaluations and myocardial scans in all patients and coronary angiography in select patients. Asymptomatic patients with normal myocardial scans (n=57) had significantly fewer cardiac events (log-rank=0.0002) and deaths (log-rank=0.0005) than did patients with abnormal scans but no angiographic evidence of CAD (n=76) and individuals with CAD (n=34) documented angiographically. CAD increased the probability of events (HR=2.27, % CI 1.007-5.11; p=0.04). The incidence of cardiac events (log-rank=0.349) and deaths (log-rank=0.588) was similar among patients treated medically (n=23) or by intervention (n=11). Asymptomatic patients with normal myocardial scans had a better cardiac prognosis than did patients with or without CAD and positive for myocardial ischemia. Patients with altered scan and CAD had the poorer outcome. Guideline-oriented medical treatment is safe and yields results comparable to coronary intervention in renal transplant patients with CAD. The data do not support preemptive myocardial revascularization for renal transplant candidates.

Cintilografia de perfusão miocárdica em pacientes diabeticos tipo 2 com dor torácica atípica

To verify the prevalence of ischemic myocardial abnormalities, 67 patients with type 2 diabetes mellitus (DM2) with normal basal electrocardiogram (EKG) or with ventricular repolarization abnormalities were evaluated by a perfusional myocardial scintigraphy. The average age was 63.5 +/- 9 years. Twenty-one (31.3%) were male and 46 (68.7%) female. A significant part of the sample (62.7%) had a normal myocardial scan, 37.3% were positive for ischemia. The majority of the sample (91%; n = 61) was submitted to an EKG during exercise which was positive for ischemia in 31.1%. The concordance between myocardial scintigraphy and the EKG during exercise demonstrated a low correlation between the two procedures (Kappa = 0.49; P = 0.0001). We conclude that perfusional myocardial scan is a highly valuable tool for evaluation and diagnosis of coronary artery disease in DM2 patients with atypical angina.

Correlation of Exercise 201Thallium Myocardial Scan with Coronary Arteriograms and the Maximal Exercise Test

Myocardial scans obtained by injecting radioactive 201thallium during exercise were correlated with electrocardiograms obtained at rest and during exercise, with coronary arteriographic abnormalities, and with left ventriculograms in 55 patients suspected of having coronary arterial disease. Thirty-nine patients had significant coronary arterial disease, 34 of whom had abnormal myocardial scans after exercise and 21 of whom had abnormal ECGs during exercise. The myocardial scan after exercise was most frequently abnormal in the presence of significant abnormalities in the Q wave or localized left ventricular asynergy and when ST-segment depression persisted for longer than ten minutes after exercise. All patients with single-vessel disease had abnormal myocardial scans after exercise, whereas five of 29 patients with two or more abnormal vessels had normal scans. Patients with coronary arterial disease were more likely to have a normal myocardial scan after exercise when the resting ECG and left ventriculogram were normal and when exercise-induced ST-segment depression persisted for less than ten minutes. The combination of the myocardial scan after exercise and the ECG during maximal exercise had a sensitivity of 98 percent. The myocardial scan after exercise alone had a specificity of 100 percent. These observations indicate that the myocardial scan obtained by injecting 201thallium during exercise is an important diagnostic adjunct in the identification of patients with coronary arterial disease.