title: Impact of untreated obstructive sleep apnea on left and right ventricular myocardial function and effects of CPAP therapy.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) has deteriorating effect on LV function, whereas its impact on RV function is controversial. We aimed to determine the effect of OSA and continuous positive airway pressure (CPAP) treatment on left and right ventricular (LV, RV) function using transthoracic echocardiography (TTE) and 2 dimensional speckle tracking (2D ST) analysis of RV deformation capability.
  
  
  RESULTS
  82 patients with OSA and need for CPAP therapy were prospectively enrolled and underwent TTE at study inclusion and after 6 months of follow up (FU). Multivariate regression analysis revealed an independent association between baseline apical right ventricular longitudinal strain (RV-Sl), BMI and the severity of OSA (apical RV-Sl: P = 0.0002, BMI: P = 0.02). After CPAP therapy, LV functional parameters (LVEF: P<0.0001, LV performance index: P = 0.03, stroke volume: P = 0.042), and apical RV-Sl (P = 0.001) improved significantly. The effect of CPAP therapy was related to severity of OSA (LVEF: AHI 5-14, 66.4 ± 8.8%, 68.5 ± 10.6% [P = ns]; AHI 15-30:59.8 ± 7.7%, 68.6 ± 9.3% [P = 0.002]; AHI>30:54.1 ± 12.4%, 68.2 ± 13.6%[P<0.0001]; apical RV-Sl: AHI 5-14: -17.3 ± 8.7%, -16.0 ± 10.8% [P = ns], AHI 15-30: -9.8 ± 6.0%, -15.4 ± 10.9% [P = 0.028], AHI>30: -6.3 ± 5.7%, -17.9 ± 11.2% [P<0.0001]).
  
  
  CONCLUSIONS
  OSA seems to have deteriorating effect on LV and RV function. We found a beneficial effect of CPAP on LV and RV functional parameters predominately in patients with severe OSA. 2D speckle tracking might be of value to determine early changes in global and regional right ventricular function.
authors.affiliation: University of Bonn, Department of Internal Medicine II, Cardiology, Pulmonology and Angiology, Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hammerstingl
authors.forename: Robert
authors.initials: R
authors.lastname: Schueler
authors.forename: Martin
authors.initials: M
authors.lastname: Wiesen
authors.forename: Diana
authors.initials: D
authors.lastname: Momcilovic
authors.forename: Stefan
authors.initials: S
authors.lastname: Pabst
authors.forename: Georg
authors.initials: G
authors.lastname: Nickenig
authors.forename: Dirk
authors.initials: D
authors.lastname: Skowasch
mesh_terms: D000368:Aged; D045422:Continuous Positive Airway Pressure; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D017286:Polysomnography; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D013318:Stroke Volume / Q000502:physiology; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*