Acute coronary syndrome and decompression illness: a challenge for the diving physician

Decompression illness (DCI) is a syndrome with diverse clinical manifestations but in which cardiac symptoms are rare. In the presence of cardiac symptoms, the necessity to rule out an acute coronary syndrome (ACS) which requires prompt treatment may result in delay to appropriate recompression treatment. We describe three cases with cardiologic symptoms referred to our centre by the Emergency Department (ED) of our facility. The first was a 48-year-old woman who lost consciousness during a dive and required cardiopulmonary resuscitation. The final diagnosis was acute myocardial infarction and the patient did not undergo recompression treatment. The second case was that of a 27-year-old man who complained of tachycardia, dyspnoea and vertigo soon after a dive. He was referred by helicopter ambulance and in the ED was diagnosed with new-onset atrial fibrillation. Recompression resulted in disappearance of his vertigo, and sinus rhythm was restored pharmacologically. The third case was a 43-year-old man, with a history of coronary artery disease, who had undergone coronary artery bypass grafting three years previously. After a repetitive dive without adequate decompression, he complained of crushing retrosternal pain and numbness in the upper left arm. All cardiovascular examinations were negative and the patient was recompressed, with resolution of his symptoms. Features to consider in arriving at the correct differential diagnosis in divers presenting with cardiac symptoms are discussed in the light of these three illustrative cases.