Usefulness of myocardial perfusion SPECT in patients with left bundle branch block and previous myocardial infarction
- J Candell-Riera1,
- G Oller-Martínez1,
- O Pereztol-Valdés2,
- J Castell-Conesa2,
- S Aguadé-Bruix2,
- M Soler-Peter2,
- M Simó2,
- C Santana-Boado1,
- J Soler-Soler1
- 1Department of Cardiology, Hospital Universitari Vall d’Hebron, Barcelona, Spain
- 2Department of Nuclear Medicine, Hospital Universitari Vall d’Hebron
- Correspondence to:
Dr J Candell-Riera, Servei de Cardiologia, Hospital Universitari Vall d’Hebron, P Vall d’Hebron 119-129, 08035 Barcelona, Spain;
- Accepted 25 March 2003
Background: The diagnostic value of myocardial perfusion scintigraphy in patients with left bundle branch block (LBBB) and previous acute myocardial infarction has not been evaluated.
Objective: To determine the utility of single photon emission computed tomography (SPECT) in patients with LBBB and previous acute myocardial infarction.
Methods: Seventy two consecutive patients with permanent LBBB and previous acute myocardial infarction were studied with stress-rest SPECT using 99mTc compounds. The same stress procedures were followed in all patients: (1) exercise alone when it was sufficient; (2) exercise plus simultaneous administration of dipyridamole if exercise was insufficient.
Results: In 26 of 28 patients (93%) who had a Q wave acute myocardial infarct before the development of LBBB, there was concordance between abnormal Q waves and rest SPECT in the localisation of myocardial necrosis (κ = 0.836; p = 0.0001). In 48 patients who had coronary angiography, the positive predictive value of exercise (+dipyridamole) myocardial SPECT for the diagnosis of left anterior descending coronary artery stenosis was 93%, for left circumflex coronary artery stenosis, 96%, and for right coronary artery stenosis, 89%. Specificity values were 83%, 91%, and 69%, respectively. However, sensitivity (69%, 64%, and 89%) and negative predictive values (48%, 46%, and 82%) were suboptimal.
Conclusions: Rest myocardial perfusion SPECT with technetium compounds is useful for localising healed myocardial infarction in patients with LBBB, and exercise (+dipyridamole) SPECT has a high positive predictive value and specificity for the diagnosis of coronary stenosis in these patients.