Influence of positive end-expiratory pressure on myocardial strain assessed by speckle tracking echocardiography in mechanically ventilated patients.
OBJECTIVE
The effects of mechanical ventilation (MV) on speckle tracking echocardiography- (STE-)derived variables are not elucidated. The aim of the study was to evaluate the effects of positive end-expiratory pressure (PEEP) ventilation on 4-chamber longitudinal strain (LS) analysis by STE.


METHODS
We studied 20 patients admitted to a mixed intensive care unit who required intubation for MV and PEEP titration due to hypoxia. STE was performed at three times: (T1) PEEP = 5 cmH2O; (T2) PEEP = 10 cmH2O; and (T3) PEEP = 15 cmH2O. STE analysis was performed offline using a dedicated software (XStrain MyLab 70 Xvision, Esaote).


RESULTS
Left peak atrial-longitudinal strain (LS) was significantly reduced from T1 to T2 and from T2 to T3 (P < 0.05). Right peak atrial-LS and right ventricular-LS showed a significant reduction only at T3 (P < 0.05). Left ventricular-LS did not change significantly during titration of PEEP. Cardiac chambers' volumes showed a significant reduction at higher levels of PEEP (P < 0.05).


CONCLUSIONS
We demonstrated for the first time that incremental PEEP affects myocardial strain values obtained with STE in intubated critically ill patients. Whenever performing STE in mechanically ventilated patients, care must be taken when PEEP is higher than 10 cmH2O to avoid misinterpreting data and making erroneous decisions.
Department of Medical Biotechnologies, Unit of Intensive Care Medicine, University of Siena, Viale Bracci 10, 53100 Siena, Italy.
Federico
F
Franchi
Agnese
A
Faltoni
Matteo
M
Cameli
Luigi
L
Muzzi
Matteo
M
Lisi
Lucia
L
Cubattoli
Sofia
S
Cecchini
Sergio
S
Mondillo
Bonizella
B
Biagioli
Fabio Silvio
FS
Taccone
Sabino
S
Scolletta
D000368:Aged; D016638:Critical Illness / Q000628:therapy; D004452:Echocardiography; D005260:Female; D006331:Heart Diseases / Q000473:pathology / Q000628:therapy*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D011175:Positive-Pressure Respiration; D012121:Respiration, Artificial