Background
Effect of inhalational anesthetics on diastolic function in humans is still controversial, although inhalational anesthetics have been shown to have negative lusitropic action in experimental studies, which were explained by interference of inhalational anesthetics with calcium homeostasis.
Aim
This prospective randomized study aims to evaluate and compare the effects of sevoflurane and desflurane on left ventricular (LV) diastolic function in patients with impaired LV relaxation due to ischemic heart disease using transesophageal Doppler echocardiography.
Patients and methods
After approval from the local ethics committee and informed consent, 24 patients scheduled for coronary artery bypass grafting surgery were enrolled in the study. Patients were selected by a preoperative transthoracic echocardiographic diagnosis of impaired relaxation or grade 1 diastolic dysfunction. Anesthetic induction was standardized in both groups. Patients randomly received 1 MAC of sevoflurane ( = 12) or desflurane ( = 12) for maintenance of anesthesia. Hemodynamic parameters and transesophageal echocardiography (TEE) derived ventricular diastolic relaxation indices before and after the study drug administration were compared. LV filling pressures were kept within normal range throughout the study period to exclude the effect of the loading conditions on diastolic function.
Results
The two study drugs significantly reduced the systemic vascular resistance index with a significant increase in the cardiac index. Hemodynamic changes measured by invasive arterial line and pulmonary artery catheter were comparable between the two groups. In terms of LV relaxation indices, the two agents led to a significant improvement in diastolic function. Transmitral and tissue Doppler E/A and Em/Am ratios improved significantly accompanied by a significant decrease in deceleration time and isovolumetric relaxation time. The effect of the two agents on diastolic relaxation parameters was comparable.
Conclusion
Sevoflurane and desflurane appear to improve LV relaxation. This can be explained by a significant reduction in afterload produced by these vapors. The positive effect of these inhalational agents on LV relaxation can have a beneficial effect on the anesthetic management of patients with diastolic dysfunction.