Lethal lung tear and coronary artery gas embolism in shallow water apnea diving exercise – PMCT, PMMRI, autopsy and histology

• Barotrauma can occur in shallow water diving without instruments.
• Buccal pumping can cause lung tears that may or may not be lethal.
• Selective post-mortem angiography can help identify not just single large vessel lesions but also diffusely injured tissue regions such as in pulmonary barotrauma.

A 45 year old man with 10 year history of accident and incident free recreational apnea diving finished an apnea warmup exercise still apparently well, gave a thumb up, and after two breaths collapsed. No success at subsequent resuscitation attempts. Post mortem computed tomography showed two pneumatoceles, a gas filled right coronary artery and some gas in the left cardiac ventricle and aorta. There were post mortem MRI T2 signal alterations in the left ventricle׳s posterior wall. Sinuses were normal. At autopsy, subpleural hemorrhages were found on both lungs with a predominance of lobe edges, indicative of mechanical strain as in mechanical breathing suppression or suffocation. Selective post mortem CT angiography of the right lung veins revealed extensive intra-alveolar leakage of contrast agent into the middle lobe, but not into the upper or lower lobes. Histology showed that fibrotic tissue and elastic fibers were not increased or decreased across lobes. The right middle lobe also contained numerous siderophages. So this is a case of recurrent pulmonary barotrauma with arterial gas embolism to the right coronary artery. This is the first case where consequences of lung pressure or barotrauma acquired at water surface by apnea as such could be documented at autopsy.