Valor da ressonância nuclear magnética na detecção da perviabilidade da artéria coronária após trombólise / Role of the Magnetic Resonance Imaging to Detect Artery Patency After Thrombolysis

PURPOSE--To determine the value of magnetic resonance imaging (MRI) in the noninvasive detection of infarct related coronary artery patency after thrombolysis. METHODS--We studied 26 patients with acute myocardial infarction submitted to thrombolysis underwent MRI studies before and after 0.1mmol/kg gadolinium-DTPA injection within the first 48 h of MI. Signal intensity was assessed by circumferential profile analysis techniques. RESULTS--The average ratio of signal intensity of infarcted tissue over normal myocardium (I/N) was significantly higher in patients with patent arteries (1.3 +/- 0.13 vs 1.12 +/- 0.07, p < 0.02). Compared to coronariography MRI, sensitivity of 81 and specificity of 100 for the diagnosis of coronary patency. CONCLUSION--Gadolinium infusion increased infarcted and normal myocardium differentiation. The study of gadolinium kinetics at MRI is a promising technique for noninvasive diagnosis of coronary patency.

A revascularizaçäo precoce das artérias näo relacionadas ao infarto melhora a funçäo regional e global do ventrículo esquerdo após o infarto agudo do miocárdio / Early Noninfarct Related Arteries Revascularization Improves Regional Wall Motion Post Myocardial Infarction

PURPOSE--To evaluate if early interventions which increase flow in the non-infarct related arteries (NRA) could improve long-term ventricular function in the non-infarct (NI) area after an acute myocardial infarction (MI). METHODS--We studied regional wall motion analyzed by the center-line method in two groups of patients with significant stenoses (> or = 70 per cent ) in the NRA after successful coronary reperfusion (chemical or mechanical thrombolysis). Group I (GI) consisted of 21 patients that were submitted to early (mean 14 days) complete surgical revascularization of both NRA and infarct related artery (IRA); the 12 group II (GII) patients underwent successful revascularization of the IRA only, with percutaneous transluminal coronary angioplasty (mean 6 days). Paired ventriculograms were obtained within 48 hours of the infarction and a mean of 17 months later. RESULTS--NI area contractility in GI patients improved from -0.35 +/- 2.16 to +0.62 +/- 1.6sd/chord (p < 0.05), whereas in GII decreased from +0.54 +/- 1.78 to -0.66 +/- 1.72 sd/chord (p < 0.05), p < 0.05 between the groups at follow-up. Mean infarct area wall motion did not differ between the two groups: from -3.04 +/- 2.43 to 2.61 +/- 2.49 sd/chord in GI (p = NS), and from -2.68 +/- 2.54 to -2.93 +/- 2.35 sd/chord in GII (p = NS). Mean global left ventricular (LV) ejection fraction did not change in GII patients (0.72 +/- 0.09 and 0.67 +/- 0.12, p = NS), but significantly increased from 0.63 +/- 0.12 to 0.72 +/- 0.11 in GI patients (p < 0.01). CONCLUSION--These data suggest that early revascularization of NRA with significant stenoses can improve not only the NI area regional contractility, but also the global LV function in the long-term follow-up of post MI patients treated with thrombolytic therapy