title: [Usefulness of Holter in the diagnosis of apnea-hypopnea syndrome in cardiac patients].
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Unidad de Cardiología, Hospital Nostra Senyora de Meritxell, Andorra, Andorra. josepmiquel.soler@gmail.com
authors.forename: José M
authors.initials: JM
authors.lastname: Soler Picart
authors.forename: Joan
authors.initials: J
authors.lastname: Martínez Benazet
authors.forename: Noemí
authors.initials: N
authors.lastname: Cerdán Riart
mesh_terms: D000465:Algorithms; D005260:Female; D006331:Heart Diseases / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000175:diagnosis*