Changes in left and right ventricular mechanics during the Mueller maneuver in healthy adults: a possible mechanism for abnormal cardiac function in patients with obstructive sleep apnea.
BACKGROUND
Obstructive sleep apnea is highly prevalent in patients with cardiovascular disease and has detrimental effects on systolic and diastolic function of the ventricles. In this research, the changes in strain (S) and strain rate (SR) during the performance of the Mueller maneuver (MM) in an effort to better understand how negative intrathoracic pressures affect ventricular mechanics.


RESULTS
The MM was performed to maintain a target intrathoracic pressure of -40 mm Hg. Echocardiography was used to measure various parameters of cardiac structure and function. Myocardial deformation measurements were performed using tissue speckle tracking. Twenty-four healthy subjects (9 women; mean age, 30+/-6 years) were studied. Global left ventricular longitudinal S in systole and SR in early filling were significantly decreased during the MM (S: baseline, -17.0+/-1.6%; MM, -14.5+/-2.2%; P<0.0001, SR: baseline, 1.09+/-0.20 s(-1); MM, 0.92+/-0.21 s(-1); P=0.01). Global right ventricular longitudinal S was also significantly decreased during the MM (baseline, -22.0+/-3.1%; MM, -17.2+/-2.5%; P<0.0001), as was global right ventricular longitudinal systolic SR (baseline, -1.34+/-0.35 s(-1); MM, -1.02+/-0.21 s(-1); P=0.0006).


CONCLUSIONS
Left ventricular and right ventricular longitudinal deformation are significantly reduced during the MM. These results suggest that negative intrathoracic pressure during apnea may contribute to changes in myocardial mechanics. These results could help explain the observed changes in left ventricular and right ventricular mechanics in patients with obstructive sleep apnea.
Department of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA.
Yuki
Y
Koshino
Hector R
HR
Villarraga
Marek
M
Orban
Charles J
CJ
Bruce
Gregg S
GS
Pressman
Pavel
P
Leinveber
Haydar K
HK
Saleh
Tomas
T
Konecny
Tomas
T
Kara
Virend K
VK
Somers
Francisco
F
Lopez-Jimenez
D000328:Adult; D000704:Analysis of Variance; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D015588:Observer Variation; D010101:Oxygen Consumption; D020181:Sleep Apnea, Obstructive; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging*