title: Effects of CPAP on right ventricular myocardial performance index in obstructive sleep apnea patients without hypertension.
abstract: OBJECTIVE
  Obstructive sleep apnoea (OSA) might cause right ventricular dysfunction and pulmonary hypertension. We aimed to determine the effects of nasal continuous positive airway pressure (CPAP) therapy on right ventricular myocardial performance index (MPI) in OSA patients without hypertension.
  
  
  METHODS
  49 subjects without hypertension, diabetes mellitus, any cardiac and pulmonary disease had overnight polysomnography and echocardiography. In 18 moderate-severe OSA (apnea-hypopnea index > or = 15) patients, right ventricular free wall diameter (RVFWD) was measured by M-mode, and right ventricular MPI was calculated as (isovolumic contraction time+ isovolumic relaxation time) / pulmonary ejection time using Doppler at baseline and after 6 months CPAP therapy.
  
  
  RESULTS
  Mean age was 46.5 +/- 4.9 year. Patients had high body mass index (BMI: 30.6 +/- 4,0 kg/m2), but there was no change in either BMI or blood pressures after 6 months. Right ventricular end-diastolic and end-systolic diameters were in normal limits at baseline, and did not change after CPAP usage. Baseline RVFWD (7.1 +/- 2.1 mm) significantly decreased after CPAP therapy (6.2 +/- 1.7 mm, p < 0.001). 15 of patients (83%) had right ventricular diastolic dysfunction at baseline, and it was completely improved in 11 of them (73%) by CPAP usage. Right ventricular global dysfunction was shown in 11 patients (61%) with a high MPI (62.2 +/- 9.3%) at baseline; and MPI was significantly decreased after CPAP therapy (47.3 +/- 8.4%, p < 0.0001), and it was completely corrected in 4 of them (36%).
  
  
  CONCLUSIONS
  CPAP therapy significantly decreases RVFWD and improves right ventricular diastolic and global functions (MPI) in OSA patients without hypertension.
authors.affiliation: Goteborg University Sahlgrenska Hospital Sleep Laboratory, Göteborg, Sweden. ndursunoglu@yahoo.com
authors.forename: Nese
authors.initials: N
authors.lastname: Dursunoglu
authors.forename: Dursun
authors.initials: D
authors.lastname: Dursunoglu
authors.forename: Sibel
authors.initials: S
authors.lastname: Ozkurt
authors.forename: Sükrü
authors.initials: S
authors.lastname: Gür
authors.forename: Güllü
authors.initials: G
authors.lastname: Ozalp
authors.forename: Fatma
authors.initials: F
authors.lastname: Evyapan
mesh_terms: D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure; D004452:Echocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000503:physiopathology* / Q000628:therapy*; D013997:Time Factors; D016278:Ventricular Function, Right