Estudo de perfusão miocárdica em portadores de bloqueio de ramo direito / Myocardial perfusion study in patients with right bundle branch block

ABSTRACT

PURPOSE: To evaluate the sensitivity and specificity of myocardial perfusion scintigraphy in the detection of coronary artery disease in patients with right bundle branch block (RBBB). METHODS: Thirty one patients (24 male, 62.3 +/- 10.5 years) with RBBB, submitted to myocardial perfusion scintigraphy associated with exercise (n = 7) or dipyridamole (n = 24) and previous cinecoronariography were studied retrospectively. Left ventricle scintigraphic image was divided in three segments corresponding to the three main epicardic coronary territories in a total of 93 segments. Cineangiographic and scintigraphic data were then compared according to the different artery territories. RESULTS: Twenty three patients had significant lesions (> or = 60) in one or more coronary arteries and eight had no obstruction. Forty nine segments were irrigated by normal coronary arteries and 44 were related to arteries that had significant lesions. Twenty out of twenty three patients showed alterations in perfusion (sensitivity = 87). All patients without coronary obstructions showed normal perfusion scintigraphy (specificity = 100). One of the segments perfused by normal coronaries showed abnormal scintigraphy. Scintigraphy showed perfusion defects in 29 out of 44 segments with coronary obstructions. Sensitivity and specificity of the method for each arterial territory were 72and 100(left descending coronary artery), 67and 94(right coronary artery), 55and 100(circunflex coronary artery), respectively. CONCLUSION: The presence of RBBB does not modify the sensitivity and specificity of the method in the detection of coronary artery disease.