Search

Objective: Myocardial performance index, the sum of the 2 isovolumic times divided by the ejection time, contains information on global systolic and diastolic function. This study was performed to determine the feasibility of right ventricular myocardial performance index measurements if measured by transesophageal echocardiography in patients under general anesthesia and positive-pressure ventilation., Design: A prospective cohort study., Setting: A tertiary care university hospital., Participants: Twenty patients undergoing elective coronary artery bypass graft surgery., Interventions: None., Measurements and Main Results: The feasibility of the right ventricular myocardial performance index measurements was assessed in awake patients by using transthoracic echocardiography and reassessed in the same patients under general anesthesia and positive-pressure ventilation using transesophageal echocardiography. The time from the cessation to the onset of 2 consecutive right ventricular inflows was measured as time A; the time from the onset to the cessation of right ventricular ejection was measured as time B. Myocardial performance index was calculated as follows: (time A-time B)/time B. A first reader independently measured all recordings twice to assess intrareader variability and a second reader once to assess interreader variability. Variability (%) was calculated as the mean absolute difference between 2 readings divided by their mean. The myocardial performance index could be measured for all patients. The point estimates of inter- and intraobserver variability of the right ventricular myocardial performance index measurements were 4.3% to 5% in awake patients and 17.8% to 19.6% in anesthetized patients., Conclusions: This finding questions the use of right ventricular myocardial performance index measurements in anesthetized patients under positive-pressure ventilation., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

The ratio of tricuspid peak early inflow velocity to peak early diastolic velocity of the lateral tricuspid annulus (the E/Ea ratio) measured by transthoracic echocardiography has been reported to correlate with right atrial (RA) pressure. In this study, the correlation between the E/Ea ratio and RA pressure was tested in 44 anesthetized, paralyzed, and mechanically ventilated patients by transesophageal echocardiography. Mean RA pressure and the following echocardiographic data were recorded simultaneously: tricuspid peak early inflow velocities by Doppler echocardiography, peak early diastolic velocity of the lateral tricuspid annulus by tissue Doppler imaging, and right ventricular and left ventricular end-diastolic areas. Linear regression did not indicate a correlation between the E/Ea ratio and RA pressure (r = -0.11, p = 0.48) or between the E/Ea ratio and the right or left ventricular end-diastolic area index; it revealed a weak correlation between RA pressure and the inspiratory plateau pressure and body mass index. In conclusion, the E/Ea ratio failed to predict RA pressure or planimetric indexes of ventricular preload in anesthetized, paralyzed, and mechanically ventilated patients. In these patients, RA pressure was largely influenced by extracardiac factors.