This may indicate a limited knowledge of the OSA syndrome by the referring primary care physician. In addition, the prevalence of RVH in patients with OSA referred to our sleep laboratory was unexpectedly high. This suggests that OSA may have been present for a protracted period of time since RVH evolves slowly. The prevalence of RVH in OSA should alert physicians to try to diagnose OSA earlier, before this cardiac abnormality develops. Earlier diagnosis would permit earlier treatment, which may prevent the development of cardiac chamber enlargement, mainly RVH. It is well known that the main morbidities of OSA are right ventricular failure and cardiac arrhythmias.17 1M Right ventricular failure has been recently ascribed to daytime hypoxemia in association with OSA. We have further documented that marked hypoxemia and prolonged apneic episodes as well as a larger number of apneas per hour during the sleep period all contribute to RVH.
Echocardiographic detection of RVH is very difficult. We used very stringent criteria and still found that 71 percent of our OSA patients had RVH.