Cardiac MRI useful for diagnosing myocarditis

Myocarditis is an important, and often unrecognized cause of dilated cardiomyopathy (DCM). Several new diagnostic methods, such as cardiac magnetic resonance imaging (MRI), are useful for diagnosing myocarditis, according to a study published in the November 2009 issue of Mayo Clinic Proceedings.

"The use of MRI is particularly significant in the diagnosis of patients with myocarditis because it is a standard, noninvasive method," says Leslie Cooper Jr., M.D., Mayo Clinic Division of Cardiovascular Diseases.

Endomyocardial biopsy may be used for patients with acute dilated cardiomyopathy associated with hemodynamic compromise, those with life-threatening arrhythmia, and those whose condition does not respond to conventional supportive therapy. "Recent improvements in staining methods of biopsy samples have made it easier to read the slides because the stain is more sensitive than previous methods," says Dr. Cooper.

Viral infection also is an important cause of myocarditis, and the spectrum of viruses known to cause myocarditis has changed in the past two decades. Important prognostic variables include the degree of left and right ventricular dysfunction, heart block, and specific histopathological forms of myocarditis.

A peer-reviewed journal, Mayo Clinic Proceedings publishes original articles and reviews dealing with clinical and laboratory medicine, clinical research, basic science research and clinical epidemiology. Mayo Clinic Proceedings is published monthly by Mayo Foundation for Medical Education and Research as part of its commitment to the medical education of physicians. The journal has been published for more than 80 years and has a circulation of 130,000 nationally and internationally. Articles are available online at www.mayoclinicproceedings.com.