Study of the Effect of Inhaled Anesthetics on Diastolic Heart Function Using a Doppler-derived Efficiency Index

Changes in Diastolic Dysfunction With the Onset of Volatile Anesthesia in Patients Undergoing Coronary Artery Bypass Grafting as Determined by a Load-independent Efficiency Index Derived From the Parameterized Doppler Analysis of Left Ventricular Filling

The purpose of this study is to determine the effect of inhaled anesthetic drugs upon diastolic heart function (heart suction and filling performance) in patients who are undergoing coronary bypass surgery.

Diastolic heart dysfunction is a significant cause of cardiovascular morbidity and is the cause of symptomatic heart failure in approximately one half of patients who are admitted to hospitals with heart failure symptoms. However, diastolic heart function remains difficult to measure objectively without cardiac catheterization. Diastolic heart dysfunction is also common among patients undergoing coronary bypass grafting (CABG) surgery. Despite the ubiquitous use of inhaled volatile drugs to maintain anesthesia in these patients, their effects upon diastolic heart function remain unclear.

Inclusion Criteria:

• Non-emergent coronary bypass grafting surgery
• Left ventricular ejection fraction of 40% or greater

Exclusion Criteria:

• Myocardial infarction within 4 weeks
• Greater than mild cardiac valvular pathology
• Body mass index greater than 35
• Cardiac dysrhythmias or pacemaker therapy
• Left bundle branch block
• Uncontrolled gastroesophageal reflux disease