title: Magnetic resonance imaging of myocardial fibrosis in hypertrophic cardiomyopathy.
abstract: Myocardial fibrosis can occur in patients who have hypertrophic cardiomyopathy in the absence of epicardial coronary disease. In such patients, myocardial fibrosis has been linked to a poorer prognosis than in those without fibrosis. Gadolinium-DTPA delayed-enhancement magnetic resonance imaging (de-MRI) accurately identifies regions of myocardial fibrosis. We used de-MRI to screen for myocardial fibrosis in 8 patients with nonobstructive hypertrophic cardiomyopathy that had been diagnosed by 2-dimensional echocardiography. After localization of the heart and acquisition of electrocardiographically gated cine images, gadolinium-DTPA (0.2 mmol/kg) was administered to the patient. Fifteen minutes later, de-MRI images were obtained using a T1-weighted, inversion-recovery fast, low-angle shot sequence. Images were gated to end-diastole and obtained during a single breath-hold. The inversion time was modified iteratively to obtain maximal nulling of the signal from the ventricular myocardium. Regions of myocardium with abnormally high signals (>300% of remote normal myocardium) were designated as fibrotic. Eight patients with hypertrophic cardiomyopathy underwent de-MRI. The mean age was 52 years, the mean left ventricular mass was 201 grams, and the mean ejection fraction was 0.68. In the 6 patients with recent clinical deterioration, de-MRI showed clearly delineated areas of myocardial fibrosis; no such areas were seen in the 2 asymptomatic patients. We conclude that patients with symptomatic hypertrophic cardiomyopathy display regions of abnormal signal intensity on de-MRI that likely represent fibrosis. This technique may provide useful information in the evaluation of such patients and warrants further study.
authors.affiliation: Department of Radiology/Cardiovascular Magnetic Resonance Imaging, St Luke's Episcopal Hospital and Texas Heart Institute, Houston, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Wilson
authors.forename: Rollo P
authors.initials: RP
authors.lastname: Villareal
authors.forename: Ramesh
authors.initials: R
authors.lastname: Hariharan
authors.forename: Ali
authors.initials: A
authors.lastname: Massumi
authors.forename: Raja
authors.initials: R
authors.lastname: Muthupillai
authors.forename: Scott D
authors.initials: SD
authors.lastname: Flamm
mesh_terms: D000328:Adult; D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000175:diagnosis*; D017023:Coronary Angiography; D004452:Echocardiography; D004719:Endomyocardial Fibrosis / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology