[Contribution of 64-slice cardiac tomodensitometry for non-invasive diagnosis of acute myocarditis]. / Apport de la tomodensitométrie cardiaque-64 coupes au diagnostic non invasif de la myocardite aiguë

BACKGROUND: The association of acute chest pain, elevation of the cardiac enzymes and biological markers of inflammation suggests the diagnosis of myocarditis. The aim of the present study is to evaluate the diagnostic value of the multidetectors cardiac tomodensitometry (MDCT) for the confirmation of this diagnosis. PATIENTS AND METHODS: From October 2005 to April 2011, 39 patients aged 15.4 to 75.7years (mean 43.3±15.1) underwent a MDCT for suspected acute myocarditis (chest pain, elevation of troponin I, systemic inflammation). The electrocardiogram highlighted repolarization disorders in 27 (69%) patients (negative T waves, elevation of ST segment). The MDCT consisted in a first acquisition phase (imaging of coronary arteries) followed 7minutes later by a late acquisition, with thicker slices (imaging of the myocardium). When the MDCT was performed after a coronary angiography, only the late acquisition was performed. Sixteen patients then underwent a cardiac MRI. RESULTS: No significant coronary stenoses were found in all patients. The MDCT showed homogeneous myocardial enhancement on the early acquisition. A subepicardial late enhancement was found in 30 (76.9%) patients. The subepicardial enhancement was mainly found in the lateral myocardium. In patients who underwent cardiac MRI and MDCT (n=16), there was a good correlation between the enhanced segments. MDCT found differential diagnosis in 11 patients (myocardial infarction, Tako-Tsubo). CONCLUSION: The ECG-gated MDCT is a non-invasive and reliable diagnostic tool in patient with suspected myocarditis. It allows at the same time to rule out a significant coronary disease, when no coronary angiography was performed, and to show subepicardial enhancement confirming the diagnosis of myocarditis. While cardiac MRI remains the gold standard, MDCT could prove useful when there is no access to or contraindication for an MRI, studying both the coronary arteries and the myocardium.

[Use of 64-slice tomodensitometry after cardiac arrest]. / Une indication de scanner 64-coupes en urgence après arrêt cardiaque réanimé

Acute coronary occlusion is the leading cause of out-of-hospital cardiac arrest, so patients are usually referred for immediate coronary angiography and angioplasty. We report here the observation of such a patient who previously underwent a coronary artery bypass intervention and who had a difficult arterial access. Moreover, the nature of the grafts was unknown (saphenous and/or mammary arteries). Multi-slice cardiac tomo-densitometry was performed rather than a conventional coronary angiography and it allowed the analysis of native arteries and grafts. There was no stenosis and angioplasty was unnecessary.

[An exceptional etiology of left ventricular aneurysm: type AA amyloidosis]. / Une cause exceptionnelle d'anévrisme du ventricule gauche: l'amylose de type AA.

Left ventricular aneurysms most often occur in the course of myocardial infarction. In rare cases they can be detected when the coronary network is devoid of any lesions. The aetiology is therefore multiple and dependent on the context. One aetiology seems less exceptional and concerns idiopathic aneurysms encountered in the African population, where the role of a "debilitating condition" such as tuberculosis has been evoked. We report the case history of a young patient from Zaire with a left ventricular aneurysm discovered in association with ganglionic tuberculosis complicated by AA amyloidosis. Histological analysis allowed the aetiological diagnosis to be established. Aneurysmal dilatation of the left ventricle was reported in the presence of amyloid deposits at the intra-myocardial arteriole level, whereas the context suggested a tubercular role. In spite of the difficulty of establishing a precise aetiological diagnosis, there seems to exist a consensus for surgical management.