A protocol to evaluate myocardial viability in ischemic left ventricular dysfunction using magnetic resonance imaging and a gadolinium-based contrast agent.

Abstract

OBJECTIVES: A protocol to evaluate myocardial viability in ischemic left ventricular dysfunction using magnetic resonance imaging and a gadolinium-based contrast agent. METHODS: Twenty-two patients were prospectively offered a cardiac MR exam between November 2003 and June 2004. Twelve had a history of anterior wall MI, eight had a history of inferior wall MI and two patients had MI of undetermined location. Eight patients had left ventricular dysfunction. RESULTS: No patient with transmural scarring extending through more than 75% of the wall recovered normal wall motion despite revascularization when evaluated fourteen months later. Of the other three with scarring extending to less than 75% there was recovery in two patients. CONCLUSION: Viability assessment by cardiac MR using gadolinium contrast is a robust technique. No segment with >75% transmural enhancement (TE) recovers despite revascularization, while all segments with <25% TE recover contractility. Between these two extremes, methods other than extent of TE may have to be used, particularly low-dose dobutamine stress testing or evaluation of percentage of hyperenhanced area compared to the normal area in each segment.