ROLE OF RESPIRATORY SLEEP DISORDERS IN THE PATHOGENESIS OF NOCTURNAL ANGINA AND ARRHYTHMIAS

This report documents how respiratory sleep disorders can adversely ef fect ischaemic heart disease. Three male patients (aged 60-67 years) w ith proven ischaemic heart disease are described. They illustrate a sp ectrum of nocturnal cardiac dysfunction, two with nocturnal angina and one with nocturnal arrhythmias. Full sleep studies were performed in a dedicated sleep laboratory on all patients, and one patient had 48 h ours of continuous Holter monitoring. Two patients were found to have obstructive sleep apnoea with apnoea/hypopnoea indices of 57 and 36 pe r hour, respectively, the former with nocturnal arrhythmias and the la tter with nocturnal angina. In both cases, nasal continuous positive a irways pressure successfully treated the sleep apnoea, with an associa ted improvement in nocturnal arrhythmias and angina. The third patient who presented with nocturnal angina, did not demonstrate obstructive sleep apnoea (apnoea/hypopnoea index = 7.2) but had significant oxygen desaturation during rapid eye movement (REM) sleep. This patient resp onded to a combination of nocturnal oxygen and protriptyline, an agent known to suppresss REM sleep, and had no further nocturnal angina. Al l patients were considered to be an optimum cardiac medication and suc cessful symptom resolution only occurred with the addition of specific therapy aimed at their sleep-related respiratory problem. We conclude that all patients with nocturnal angina or arrhythmias should have re spiratory sleep abnormalities considered in their assessment.