Influence of Positive End-Expiratory Pressure on Myocardial Strain Assessed by Speckle Tracking Echocardiography in Mechanically Ventilated Patients

Table 4

Univariate analysis between patients with a stroke volume reduction (Δ) lower and greater than 15%. Values are expressed as mean ± standard deviation.

Parameter	Δ SV ≤ 15%; (𝑁=6)	Δ SV > 15%; (𝑁=14)	𝑃
Δ LV-EDV (mL)	−4.3±3.6	−17.3±9.4	<0.05
Δ LV-LS (%)	3.0±1.4	2.6±3.1	0.79
Δ RV-EDD (mm)	9.5±2.6	9.1±4.3	0.83
Δ RV-LS (%)	3.9±1.3	3.7±1.4	0.89
Δ LAV ( mL)	−6.2±2.7	−13.7±7.5	<0.05
Δ LA-PALS (%)	−12.2±3.7	−11.5±6.6	0.80
Δ RAV (mL)	−8.7±4.1	−8.7±3.9	0.97
Δ RA-PALS (%)	−11.0±6.9	−8.1±3.9	0.24

Δ: changes in measures over time, obtained by subtracting the first measurement (at PEEP of 5 cmH₂O) from the third (at PEEP of 15 cmH₂O); LV-EDV: left ventricular end diastolic volume; LV-LS: left ventricular longitudinal strain; RV-EDD: right ventricular end diastolic diameters; RV-LS: right ventricular longitudinal strain; LAV: left atrial volume; LA-PALS: peak left atrial longitudinal strain; RAV: right atrium volume; RA-PALS: peak right atrial longitudinal strain.