Respirophasic Carotid Artery Peak Velocity Variation as a Predictor of Fluid Responsiveness in Patients With Coronary Disease

The aim of this study is to investigate usefulness of the respirophasic variation in carotid artery peak flow velocity measured by Doppler ultrasound, which is noninvasive and easily accessible, as a predictor of fluid responsiveness in patients with coronary artery disease.

Inclusion Criteria:

1. patients scheduled for elective isolated off-pump coronary artery bypass graft surgery

Exclusion Criteria:

1. cardiac rhythm other than sinus
2. congestive heart failure
3. left ventricular ejection fraction <35%
4. history of transient ischemic attack
5. pre-existing cerebrovascular disease and peripheral arterial occlusive disease
6. presence of carotid artery stenosis >50%