The importance of cardiac MRI as a diagnostic tool in viral myocarditis-induced cardiomyopathy

Abstract

Myocarditis is an acute or chronic inflammatory disease of the myocardium which can be viral, postinfectious immune or primarily organ-specific autoimmune. Clinical manifestations of acute and chronic myocarditis are extremely varied, ranging from mild to severe. Affected patients may recover or develop (dilated) cardiomyopathy (DCM) with life-threatening symptoms including heart failure, conduction disturbances, arrhythmias, cardiogenic shock or sudden cardiac death.The diagnosis of myocarditis is a challenging process and not only because of a diverse presentation; other problems are limited sensitivity of endomyocardial biopsies (EMB) and overlapping symptoms. Furthermore, the diagnosis is not well defined. However, early diagnosis is mandatory to address specific aetiology-directed therapeutic management in myocarditis that influences patient morbidity and mortality.Currently, EMB remains the only way to confirm the presence of a viral genome and other histopathological findings allowing proper treatment to be implemented in cases of myocarditis. Increased recognition of the role of myocardial inflammatory changes has given rise to interest in noninvasive imaging as a diagnostic tool, especially cardiovascular magnetic resonance imaging (CMR). In this review we discuss the current role of CMR in the evaluation of myocarditis-induced inflammatory cardiomyopathies. (Neth Heart J 2009;17:481-6.).

Keywords: cardiac magnetic resonance imaging; cardiomyopathy; myocarditis.

Figure 1

Ischaemic anteroseptal infarction. A) Short-axis view showing a transmural pattern of contrast enhancement in the anteroseptal and inferoseptal wall. B) Four-chamber view showing a transmural pattern of contrast enhancement in the inferoseptal and apical wall.

Figure 2

Eosinophilic myocarditis. A) Short-axis view showing a pattern of subendocardial and midwall contrast enhancement in the anteroseptal and inferoseptal wall. B) Four-chamber view showing subendocardial and midwall contrast enhancement in the inferoseptal wall.

Figure 3

Myocarditis. A) Short-axis view and four-chamber view showing a pattern of midwall contrast enhancement in the septal wall, B) Four-chamber view showing a pattern of midwall contrast enhancement in the inferoseptal wall.

Figure 4

Acute and chronic phase of myocarditis in a patient. A, B) Acute myocarditis: short-axis view and four-chamber view showing an extensive pattern of midwall contrast enhancement. Only the basal septal wall and distal anterolateral wall are spared. C, D) Chronic myocarditis: short-axis and fourchamber view showing the same pattern of midwall delayed contrast enhancement with lower signal intensity.