[Cardiopulmonary risk factors in patients with sleep apnea]

Since the interaction between disorders of the respiratory coordination and cardiovascular or cardiopulmonary regulation is still largely unknown the intention of the present investigation is to point out the coincidence of cardiac arrhythmias, such as premature ventricular capture (PVC) beats and conduction blocks, with obstructive sleep apnea (OSA). For the first time a group of more than 300 patients with suspected OSA is examined concerning risk factors and frequent diagnoses as obesity, hypertension, coronary heart disease (CHD), heart insufficiency, chronic obstructive pulmonary disease (COPD), and daytime hypoxaemia. Summarizing the results of lung function test, blood gas analysis, strain-ECG, Holter-ECG and inductive plethysmography with oxygen partial pressure measurement by ambulatory work-up the following statements can be made: PVC beats occurring markedly during sleep give hints for OSA being the underlying cause, especially if the patients are young and overweight. Hypoxaemia increasing during the apnea episodes should be considered as one possible pathogenetic mechanism. Second- and third degree conduction blocks and sinus arrest coincident very often with OSA. They suggest to be life-limiting factors the more so since they often go along with CHD or heart insufficiency. Systemic arterial hypertension and overweight have the highest prevalence in OSA, signs for heart insufficiency and daytime hypoxaemia are also significantly more frequent than in non-OSA patients. We could find no hints for direct pathogenetic coherence between CHD and OSA or between COPD and OSA, nevertheless pronounced nocturnal changes in blood gases and intrathoracic hemodynamics have important influence on the cardiopulmonary and cardiovascular system, as partly illuminated in other more pathogenetic oriented studies by the present time.