Impact of obstructive sleep apnea on right ventricular global function: sleep apnea and myocardial performance index.
BACKGROUND
Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstructions during sleep, and it might cause cardiovascular complications such as heart failure, arrhythmias, myocardial infarction, systemic and pulmonary hypertension.


OBJECTIVE
To determine right ventricular diameters and myocardial performance index (MPI) reflecting ventricular global function in uncomplicated OSA patients.


METHODS
49 subjects without hypertension, diabetes mellitus, or any cardiac or pulmonary disease referred for evaluation of OSA had overnight polysomnography and complete echocardiographic assessment. According to the apnea-hypopnea index (AHI), subjects were divided into three groups: group 1: control subjects (AHI <5, n = 20), group 2: patients with mild OSA (AHI: 5-14, n = 11), and group 3: moderate-severe OSA (AHI > or = 15, n = 18). Right ventricular free wall diameter was measured by M mode, and right ventricular MPI was calculated as (isovolumic contraction time + isovolumic relaxation time)/pulmonary ejection time.


RESULTS
There were no differences of age, body mass index, heart rates, systolic and diastolic blood pressures among the groups (p > 0.05). Right ventricular end-diastolic and end-systolic diameters were not statistically different between the groups, and were within normal limits. Also, right ventricular free wall diameter was not significantly different between the groups of control, mild OSA and moderate-severe OSA (6.7 +/- 0.9, 6.9 +/- 1.0, 7.1 +/- 1.1 mm, p > 0.05). Right ventricular diastolic dysfunction was shown only in group 3 patients. Right ventricular MPI was statistically higher in group 3 (0.62 +/- 0.18) than in group 2 patients (0.50 +/- 0.10), and group 1 patients (0.48 +/- 0.08, p < 0.001).


CONCLUSIONS
It was suggested that patients with moderate-severe OSA had a right ventricular global dysfunction, in addition to the presence of a diastolic dysfunction.
Dursunoğlu
Nese
N
Department of Chest Disease, Pamukkale University Medical Faculty, Denizli, Turkey.
Dursunoğlu
Dursun
D
Kiliç
Mustafa
M
D000328:Adult; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000145:classification / Q000503:physiopathology*; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology