Myocardial Contusion

Report:

Sinus tachycardia 100/min

First degree AV block

Right bundle branch block

Inferior infarction ?age

Possible atrial infarction

Poor R wave progression

Comment:

The trace is very abnormal and, in the context of blunt chest trauma, quite suggestive of myocardial contusion. Echocardiogram showed dilated hypokinetic right and normal left ventricle. Troponin rose to 3.8 (normal < 1 µg/L) with much greater, as expected, CPK rise. She recovered uneventfully; there were no specific cardiac interventions (except elevating her CVP to 20 cms H2O on admission, to maintain the blood pressure).

Significant blunt myocardial trauma is rare and, even when documented, usually does not amount to much5. This said, it must be owned that many patients, like this one, are in ICU on other grounds. Cardiac contribution to multitrauma pathology is difficult to define as is, indeed, the very entity of “contusion”6.

Right ventricle is more commonly involved than the left, and RBBB is the commonest conduction defect. The RA “infarction” possibility is raised because of the prominent PR segment shift and coexisting RV abnormalities.

The patient was known to have a healed inferior infarction with 1o AV block three years previously; the same pattern persisted four years after the current admission. Her T waves tended to merge with P waves even then; the current tracing gives an impression (dispelled in aVL) that there is long QT interval or large TU waves. Her potassium was normal.

The next day the RBBB resolved (Fig 3a).

3a. Sinus tachycardia. P waves are still difficult to discern. 4. 65 year old lady with ascites and peripheral œdema