Background and objective: Several studies have described the changes observed in the response of the autonomous nervous system in patients with obstructive sleep apnea syndrome (OSAS). From the point of view of cardiology outpatients, we tried to relate the presence of the disease with the behavior of a Holter algorithm, the very low frequency increment (VLFI), in a direct relationship to sympathetic regulation during sleep. In addition, we studied the characteristics of our population group with regard to OSAS.
Patients and method: Over a period of 2 years we included 147 patients, checking them all out with a 24-h Holter and a polygraphic recording of sleep. We separated out 3 subgroups of patients: slight OSAS, moderate-severe OSAS and patients with no OSAS. We correlated the variable VLFI and other clinical characteristics in the 3 subgroups.
Results: 74% of the patients were diagnosed with OSAS, notably in association with the presence of cardiopathy at more advanced stages of the disease. Moreover, a significant relationship was obtained between moderate to severe OSAS and an increase of VLFI in men but not in women and in less severe stages of the syndrome.
Conclusions: In our study the variable VLFI of the Holter represented a very useful contribution when studying patients with a suspected ambulatory SAHS. Furthermore, this practice could help in the screening of this illness.