Author:Paulo R. Schvartzman, M.D., Ph.D.

Escola Paulista de Medicina, Unifesp, São Paulo, Brazil

Authored date:2006-11-30

Patient History

A 38-year-old female complained of chest pain associated with exercise, which resolved after 2–3 min of rest. Echo demonstrated an asymmetrical septal hypertrophy with no left ventricular outflow obstruction. A stress nuclear test was performed and no perfusion deficit was detected. Stress perfusion cardiac magnetic resonance was requested to define if chest pain was secondary to a perfusion deficit.

Stress MR protocol*

The cardiac magnetic resonance exam protocol was as follows:

1. Cine-images on three long-axis views (two, three and four chamber view) and three short 
     axis-views (base, mid-ventricular and apical).

2. Dipyridamole stress perfusion images in four short axis slices acquired 2 min after a
     4 min dipyridamole injection and CM.

3. Short axis TrueFISP cine images were obtained from base to apex to define LV volumes.

4. Rest perfusion on the same four short axis views as the slices of stress perfusion.

5. Tissue characterization images acquired 15 min after CM on the same image plane as 
     previous long axis and shortaxis views to define the presence of myocardial fibrosis.

Image Findings

The TrueFISP cine images in the four-chamber view (Fig. 1) and short-axis view (Fig. 2) documented the
extensive (32 mm – arrowhead) and asymmetrical (arrow) hypertrophy. The stress perfusion* short-axis
image (Fig. 3, left) demonstrates a septal perfusion deficit (arrow) during the gadolinium injection.
The rest perfusion image demonstrates normal (arrow) perfusion (Fig. 3, right). Tissue characterization
image* after CM in the 4 chamber view (Fig. 4, left) and short-axis view (Fig. 4, right) demonstrate the
septal hypertrophy and absence of myocardial fibrosis.

Fig. 1  Four chamber view in diastole (A)
and systole (B) demonstrating extensive
septal hypertrophy.

Fig. 2  Basal short axis images in diastole
(left) and systole (right) demonstrating the
septum hypertrophy.

Fig. 3  Stress perfusion basal short axis view 2
minutes after the end of a 4-minute dipyridamole
infusion (left) and rest perfusion (right) images.

Fig. 4  Delayedenhancement images 10 min. after gadolinium injection
(0.4 ml/kg) demonstrate the absence of myocardial fibrosis on the
four-chamber view (left) and basal short axis-view (right).

Results and Discussions

The characteristic finding of inappropriate myocardial hypertrophy in the absence of an obvious cause for the hypertrophy is the marker for hypertrophic cardiomyopathy. This is a genetic disease associated with eight different genes, and frequently it does not present with symptoms. Often the diagnosis is made by a routine echo. Several patients may complain of chest pain and dyspnea, despite normal coronary arteries. The perfusion deficit with normal coronary arteries is secondary to a disproportion of extensive hypertrophy and normal coronary flow.
Nuclear stress testing is usually performed to rule out coronary artery disease in patients with chest pain and hypertrophic cardiomyopathy. However due to suboptimal spatial resolution, smaller perfusion deficits may not be detected.
This case represents an application of cardiac magnetic resonance in patients with chest pain and normal stress imaging test. The exercise-related chest pain in this young female patient with asymmetrical septal cardiomyopathy, normal coronary arteries, normal nuclear stress testing – but an abnormal perfusion deficit – was properly diagnosed by cardiac magnetic resonance. This deficit is explained by an imbalance of severe hypertrophy and normal myocardial perfusion.

*The information about this product is preliminary. The product is under development. It is not commercially available in the US and its future availability cannot be assured.