Associazione Nazionale Medici Cardiologi Ospedalieri



Myocarditis, coronary artery dissection or both: a juvenile enigma

Sala Elena Milano(Milano) – Ospedale San Carlo Borromeo | Cereda Alberto Milano(Milano) – Ospedale San Carlo Borromeo | Di Giovine Gabriella Milano(Milano) – Ospedale San Carlo Borromeo

A 26-year-old man was admitted to the Coronary Care Unit for severe, non-irradiated, oppressive anterothoracic pain. He had no relevant pathological history, but reported an episode of gastroenteritis the week before. EKG showed sinus rhythm and accelerated idioventricular rhythm phases. Blood pressure and 2D echo were normal. Inflammation indeces were negative, hsTnT reached a peak of 2026 ng/L. Despite the absence of inflammation signs, our first guess was myocarditis.

Cardiac magnetic resonance (CMR) was performed: T2w-STIR images showed edema of the middle inferior wall and of the mid-basal anterior and anterolateral wall, while T1-weighted post gadolinium images showed transmural enhancement of the mid-basal anterior, antero lateral and inferior walls with a dubious origin from the sub endocardium in the anterior and anterolateral segments; LVEF was 55%.

Invasive coronary angiography (ICA) was performed to rule out ischemic etiology: LAD showed a very thin lumen in its periphery and two obtuse marginal branches had an amputated appearance: it made us think of healing dissections. Then it turned out that the patient have been working out with heavy weights the day before: we therefore considered spontaneous coronary artery dissection. Such hypothesis was consistent with the absence of inflammations indices, but didn’t explain the basal and middle inferior involvement that CMR had shown. On the other hand, the angiographic finding may be consistent with peripheral vascular suffering linked to myocarditis induced inflammation.

To date, we haven’t found univocal interpretation. Anti-remodeling therapy with IACE and beta blockers was administered, in addition to acetylsalicylic acid.

CMR will be performed in two months and may provide further results once the edema will be reabsorbed. ICA will be repeated to make sure that distal coronary blood flow is improved.

Take home messages:

Myocarditis can also occur with no signs of inflammation.
In myocarditis it has been demonstrated that slower distal coronary blood flow may occur, due to the increase in peripheral vascular resistance linked to the presence of edema.
In the acute phase, especially if CMR is performed very early, the large amount of edema can make the enhancement transmural, masking the site of origin of the damage.