Role of 3 Tesla Magnetic Resonance Imaging in the Assessment of Infiltrative Cardiomyopathies.

Background: The aim of the present study was to assess the role of 3 Tesla (3T) magnetic resonance imaging (MRI) in the assessment of infiltrative cardiomyopathy (ICM).

Methods: Cardiac MRI was performed on a 3T MRI machine for 15 patients who had clinical or echocardiographic signs of infiltrative cardiomyopathy. Each scan was assessed on a set of anatomical and functional parameters. The patterns of left ventricular (LV) late gadolinium enhancement (LGE) were also analyzed.

Results: Bi-atrial dilatation was noted in 14 patients, consistent with a restrictive phenotype. All 15 patients had diastolic dysfunction with reduced LV diastolic ventricular filling and prolonged peak filling times. Eleven patients had a decreased peak filling rate. Twelve patients had systolic dysfunction with reduced ejection fraction (EF). Ten patients had contractile dysfunction in the form of global LV hypokinesia. On delayed contrast imaging, four patients showed no abnormal LGE. Two patients showed diffuse subendocardial enhancement. Two patients showed patchy subendocardial enhancement. Six patients showed patchy mid-myocardial enhancement. One patient showed diffuse mid-myocardial enhancement. Three patients showed patchy subepicardial enhancement. Two patients showed patchy transmural enhancement. Three patients showed reversed myocardial nulling. All 15 patients received a provisional diagnosis of infiltrative cardiomyopathy on the basis of cardiac MRI findings. Sarcoidosis was given as a probable cause in four patients, amyloidosis in three patients, an infectious cause in two patients, and drug-induced cardiomyopathy in one patient. In five patients, no obvious cause could be identified.

Conclusion: Infiltrative cardiomyopathies, although relatively uncommon, pose significant challenges in diagnosis and treatment. Cardiac MRI has become the gold standard for non-invasive diagnosis of all infiltrative cardiomyopathies.