ABSTRACT
OBJECTIVE: The authors hypothesized that variations in electrocardiographically derived R-wave amplitude might be correlated with mechanical ventilation-induced variations in stroke volume as determined by transesophageal echocardiography. DESIGN: Observational prospective study. SETTING: Single university hospital. PARTICIPANTS: Thirty-four patients undergoing coronary artery bypass surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Respiratory R-wave variations in lead II (ΔRII) were correlated with aortic velocity time integral variations (r = 0.82, p < 0.0001). Respiratory R-wave variations in leads III and aVF and pulse pressure variation also were correlated with aortic velocity time integral variations (r = 0.49, p = 0.015; r = 0.61, p = 0.0016; and r = 0.72, p < 0.0001, respectively). R-wave respiratory variations in lead V(5) were not correlated with aortic velocity time integral variations. ΔRII was correlated with pulse pressure variation (r = 0.71, p < 0.0001). A ΔRII cutoff value of 15% accurately predicted stroke volume variations >15%, with a specificity of 92%, a sensitivity of 86%, a positive likelihood ratio of 11.1, a negative likelihood ratio of 0.15, a positive predictive value of 95%, and a negative predictive value of 80%. CONCLUSIONS: ΔRII is correlated with stroke volume variations as determined by transesophageal echocardiography in mechanically ventilated patients and can identify the stroke volume variation cutoff of 15%, previously determined to be the cutoff for volume responsiveness.
Subject(s)
Coronary Artery Bypass , Monitoring, Intraoperative/methods , Respiratory Mechanics/physiology , Stroke Volume/physiology , Adult , Aged , Aged, 80 and over , Aorta/physiopathology , Blood Flow Velocity/physiology , Blood Pressure/physiology , Echocardiography, Transesophageal/methods , Electrocardiography/methods , Female , Hemodynamics/physiology , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Respiration, ArtificialABSTRACT
AIMS: Left ventricular (LV) dysfunction is the first cause of late mortality after mitral valve surgery. In this retrospective analysis, we studied the association between preoperative echocardiographic LV measures and occurrence of LV dysfunction after mitral valve repair (MVR). METHODS AND RESULTS: Between 1991 and 2009, 335 consecutive patients underwent MVR for severe mitral regurgitation due to leaflet prolapse in our institution. Echocardiography was performed preoperatively and at 10.8 (9.1-12.0) months after surgery in 303 patients who represented the study population. Cardiac events were recorded during follow-up. LV ejection fraction (EF) decreased from 68 ± 9% before surgery to 59 ± 9% post-operatively (P < 0.001). Preoperative EF <64% and LV end-systolic diameter (ESD) ≥ 37 mm were the best cut-off values for the prediction of post-operative LV dysfunction (EF < 50%). On the basis of a combined analysis, the occurrence of post-operative LV dysfunction was 9% when EF was ≥ 64% and LVESD < 37 mm, 21% with EF < 64% or LVESD ≥ 37 mm, and 33% with EF < 64% and LVESD ≥ 37 mm (P for trend < 0.001). The combined variable EF < 64% and LVESD ≥ 37 mm added incremental prognostic value to the multivariable regression model (P = 0.001). CONCLUSION: Simple preoperative echocardiography measures allow the prediction of LV dysfunction after MVR in patients with leaflet prolapse. Patients with preoperative EF ≥ 64% and LVESD < 37 mm incur relatively low risk of post-operative LV dysfunction.