Sleep Apnea Syndrome: Central Sleep Apnea and Pulmonary Hypertension Worsened during Treatment with Auto-CPAP, but Improved by Adaptive Servo-Ventilation

In this 71-year-old man diagnosed as obstructive sleep apnea syndrome initially, the apnea-hypopnea index in polysomnography was 31.3/hour. He started auto-adjusted continuous positive airway pressure (auto-CPAP) treatment in July 2005 but developed congestive heart failure in December 2007. Pulmonary arterial pressure (PAP), estimated by echocardiography, was 71 mmHg. In January 2008, during simplified sleep examination with a breath-movement sensor under auto-CPAP, many central-type apneas were recognized. After replacing auto-CPAP with adaptive servo-ventilation (ASV), the apnea-hypopnea index was 5.3/hour and PAP became 36 mmHg after 3 months. It was thought that the increase of PAP was due to long-term inadequate use of auto-CPAP.