Pneumomyocardium: an unusual complication of barotrauma.

We report a 22-day-old infant who developed Staphylococcus aureus pneumonia with abscesses, pneumatoceles, and sepsis at 10 days of life. Mechanical ventilation was complicated by pneumothorax. At autopsy, a collection of air was found in the interventricular septum of the heart, a lesion we have termed pneumomyocardium. No hemorrhage, inflammatory infiltrate, organisms, or necrotic debris was found on the edge of the area of interstitial emphysema in the heart. We believe that the pneumomyocardium arose as a consequence of barotrauma.