Doppler indices of diastolic transmitral flow velocity are invalid indicators of myocardial ischaemia during high-dose dobutamine infusion in anaesthetized patients.

BACKGROUND AND OBJECTIVE: Doppler echocardiography of diastolic transmitral flow velocity is more sensitive for the detection of myocardial ischaemia in awake patients than echocardiographic analysis of systolic wall motion. However, its diagnostic value in anaesthetized patients is unknown. METHODS: Doppler indices of diastolic transmitral flow velocity previously found to be highly sensitive for detecting ischaemia in awake patients were studied in 72 anaesthetized patients with documented coronary artery disease undergoing dobutamine stress echocardiography. These Doppler indices were compared with standard echocardiographic and electrocardiographic criteria for ischaemia. RESULTS: Sixty-five patients showed evidence of ischaemia by standard echocardiographic and/or electrocardiographic criteria, and seven patients did not. Regardless of evidence of ischaemia by standard criteria, the Doppler indices changed similarly in both groups. Accordingly, only a minority of anaesthetized patients displayed the changes in Doppler indices of diastolic transmitral flow previously suggested to be sensitive for detecting ischaemia. CONCLUSIONS: The results do not confirm the diagnostic value of Doppler echocardiography of diastolic transmitral flow velocity for detecting ischaemia in anaesthetized patients undergoing dobutamine stress echocardiography during positive-pressure ventilation of the lungs.