title: Myocardial perfusion in patients with a totally occluded left anterior descending coronary artery reinjected by a normal right coronary artery: the role of collateral circulation.
abstract: In this article, myocardial perfusion in patients with a totally occluded left anterior descending artery reinjected by a normal right coronary artery is assessed using stress single photon emission computed tomography (SPECT). In all, 20 patients, with a totally occluded left anterior descending artery reinjected by normal right coronary artery, underwent myocardial single photon emission computed tomography imaging within 60 days of angiography. All patients had abnormal perfusion single photon emission computed tomography results and 70% had reversible defects. Perfusion defects at rest were present in 75% of patients, with perinecrotic residual ischemia in 45% of patients whereas for 30% of patients, no viable myocardium was detected in the collateral-dependent segments. In all, 25% of patients had no resting perfusion defects but all are presented with stress-induced ischemia. Collaterals are not protective against stress-induced ischemia, but they can preserve myocardial viability. This conclusion is highly supported by the presence of residual ischemia in the collateral-dependent segments.
authors.affiliation: Department of Cardiology, Clemenceau Medical Center, Beirut, Lebanon. elie.chammas@cmc.com.lb
authors.forename: Elie
authors.initials: E
authors.lastname: Chammas
authors.forename: Ayman
authors.initials: A
authors.lastname: Hussein
authors.forename: Ghada
authors.initials: G
authors.lastname: Ballane
authors.forename: Antoine
authors.initials: A
authors.lastname: Helou
authors.forename: Ahmad
authors.initials: A
authors.lastname: Yatim
authors.forename: Walid
authors.initials: W
authors.lastname: Tarcha
authors.forename: Georges
authors.initials: G
authors.lastname: Ghanem
mesh_terms: D000368:Aged; D003097:Collateral Circulation; D017023:Coronary Angiography; D003326:Coronary Circulation; D054059:Coronary Occlusion / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D004452:Echocardiography; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D015899:Tomography, Emission-Computed, Single-Photon