title: Left ventricular hypertrophy is a common echocardiographic abnormality in severe obstructive sleep apnea and reverses with nasal continuous positive airway pressure.
abstract: OBJECTIVE
  To determine cardiac structural abnormalities by echocardiography in subjects with severe obstructive sleep apnea (OSA), and to determine the long-term effects of nasal continuous positive airway pressure (CPAP) on such abnormalities.
  
  
  METHODS
  Polysomnography was conducted on oximetry-screened patients who showed a desaturation index > 40/h and > or = 20% cumulative time spent below 90%. From these, 25 patients with severe OSA but without daytime hypoxemia underwent echocardiography prior to, then 1 month and 6 months following initiation of CPAP treatment.
  
  
  METHODS
  Outpatient sleep disorders center.
  
  
  RESULTS
  Of the 25 patients, 13 patients (52%) had hypertension by history or on physical examination. Baseline echocardiograms showed that severe OSA was associated with numerous cardiovascular abnormalities, including left ventricular hypertrophy (LVH) [88%], left atrial enlargement (LAE) [64%], right atrial enlargement (RAE) [48%], and right ventricular hypertrophy (16%). In all patients (intent to treat) as well as those patients compliant with CPAP therapy (84% > 3 h nightly), there was a significant reduction in LVH after 6 months of CPAP therapy as measured by interventricular septal distance (baseline diastolic mean, 13.0 mm; 6-month mean after CPAP, 12.3 mm; p < 0.02). RAE and LAE were unchanged after CPAP therapy.
  
  
  CONCLUSIONS
  LVH was present in high frequency in subjects with severe OSA and regressed after 6 months of nasal CPAP therapy.
authors.affiliation: Intermountain Sleep Disorders Center, LDS Hospital, Salt Lake City, Utah 84143, USA. ldtclowa@ihc.com
authors.forename: Tom V
authors.initials: TV
authors.lastname: Cloward
authors.forename: James M
authors.initials: JM
authors.lastname: Walker
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Farney
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications* / Q000000981:diagnostic imaging; D000860:Hypoxia / Q000150:complications*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011175:Positive-Pressure Respiration / Q000379:methods*; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D014463:Ultrasonography