Relations between respiratory changes in R-wave amplitude and arterial pulse pressure in mechanically ventilated patients

Abstract

Introduction. R-wave obtained from the electrocardiogram depends on ventricular stroke volume. We assessed the relationship between respiratory variations in R-wave (ΔRDII) and in pulse pressure (ΔPP) during general anesthesia. Method. R-wave amplitude was measured from standard lead II (RDII). Maximal RDII (RDIImax) and minimal RDII (RDIImin) were determined over one respiratory cycle. ΔRDII was calculated as 100×[RDIImax-RDIImin] /([RDIImax + RDIImin]/2. ΔRDII and ΔPP were simultaneously recorded. Results. There was a significant relationship (r = 0.79; P<0.001) between ΔRDII and ΔPP. A ΔRDII >13% detected patients with a ΔPP>13% with an 89% sensitivity, and an 88% specificity. Conclusion. ΔRDII and ΔPP are related in this setting. © Springer 2010.