Cardiac Case Study: November 2010

Presented by Louise E. J. Thomson, MBChB , cardiac imaging and nuclear medicine physician at the S. Mark Taper Foundation Imaging Center.

Cardiovascular magnetic resonance offers comprehensive non invasive assessment of cardiac structure, function and tissue characterization for patients with a variety of cardiomyopathies.

'Hypertrophic heart disease' includes a spectrum of diseases with increased thickness of the myocardium. Whereas normal wall thickness is approximately 8mm, hypertrophied muscle can measure over 3cm. This muscle becomes stiff and may obstruct normal blood flow within the heart. Symptoms include presence of chest pain and breathlessness and this process may be associated with increased risk of sudden cardiac death related to arrhythmia, or onset of heart failure. Hypertrophic heart disease may be inherited, and screening imaging is performed for the offspring of patients with this form of disease.

The images A-D (click on the images to see larger size) demonstrate the thickened appearance of the myocardium in a patient with an apical variant of hypertrophic cardiomyopathy (Yamaguchi's Syndrome).

The long axis image (A) shows four cardiac chambers with marked wall thickness increase in the distal left ventricle (*).

The corresponding contrast enhanced image demonstrates presence of scar within the abnormal myocardium (1).

Images C and D are corresponding short axis slices through the distal ventricle demonstrating the circumferential nature of the process with near obliteration of the ventricular cavity by hypertrophied muscle.

The images E - F demonstrate a case of asymmetric hypertrophy of the myocardium immediately below the ventricular outflow tract, with the turbulent flow below the aortic valve in a velocity coded MR image (E, arrow) and the corresponding anatomic image (F). Tagged imaging (H) is used to confirm the abnormal pattern of contraction within the diseased segment.

Cardiovascular magnetic resonance enhances the assessment of left ventricular hypertrophy, and represents a powerful supplemental imaging test to echocardiography with distinct diagnostic advantages for selected patients (2).

The non-invasive demonstration of dynamic obstruction, scar and extreme wall thickness aids in risk assessment (3).