Related Experiment Videos
[Coronary artery bypass grafting under bradycardia induced by ultra-short acting beta blocker]
Y Miyamoto1, T Takahashi, K Kadoba
1First Department of Surgery, Osaka University Medical School, Japan.
Insights
Esmolol effectively induced bradycardia for coronary artery bypass grafting (CABG) in high-risk patients, facilitating off-pump procedures and demonstrating good graft patency. This technique is beneficial for patients with severe aortic disease or low ejection fraction.
Area of Science:
- Cardiovascular Surgery
- Pharmacology
Background:
- Coronary artery bypass grafting (CABG) traditionally involves aortic cross-clamping, posing risks for patients with specific comorbidities.
- High-risk patients, including those with porcelain aorta or low ejection fraction, may benefit from alternative surgical approaches.
Purpose of the Study:
- To evaluate the efficacy and safety of inducing bradycardia with esmolol during CABG.
- To assess the feasibility of performing CABG under beating heart conditions in selected high-risk patients.
Main Methods:
- Seven patients (ages 51-68) underwent CABG with esmolol-induced bradycardia.
- Esmolol was administered as an intravenous bolus followed by continuous infusion to achieve heart rates around 49 bpm.
- Cardiopulmonary bypass was maintained at tepid temperatures with high flow rates.
Main Results:
- Severe bradycardia was achieved (78 to 49 bpm, p < 0.01).
- An average of 3.6 anastomoses were performed per patient with 88% graft patency.
- Low postoperative cardiac enzyme levels (CPK-MB) were observed.
Conclusions:
- Esmolol-induced bradycardia facilitates beating heart CABG.
- This technique is a suitable alternative for patients with severe atheromatous disease or low ejection fraction, avoiding aortic cross-clamping.
Abstract:
From Dec. 1993 to May, 1994, coronary artery bypass grafting (CABG) was performed in 7 patients under bradycardia induced by an ultra-short acting beta blocker (esmolol). The ages ranged from 51 to 68 years. There was one patient with low ejection fraction (EF = 31%) and two patients with porcelain aorta. A tepid temperature was maintained during cardiopulmonary bypass (CPB). A high flow rate of 2.2-2.6 liter/min/m2 was applied to control perfusion pressure above 50 mmHg during CPB. After CPB was started, a high dose of esomolol was added (10-30 mg/kg intravenous bolus followed by a continuous infusion of 1-4 mg/kg/min). Severe bradycardia was achieved by the initial loading of esmolol. The mean heart rate was significantly (p < 0.01) decreased from 78 +/- 12 bpm to 49 +/- 7 bpm by the loading. Altogether, 25 anastomoses (11 ITA, 6 GEA, 8 SVG) were performed to LAD (10), Cx (7) and RCA (8), with an average of 3.6 +/- 0.9 anastomoses/patient. IABP was required for 2 patients postoperatively. There was no operative death, but one hospital death due to aspiration pneumonia 3 months later. Postoperative max CPK-MB was low (17.4 +/- 9.7 IU/L) in 6 patients. The postoperative angiography was performed in all patients with a patency rate of 88%. It was considered that esmolol facilitated CABG under beating heart and this technique is suitable for patients with severe atheromatous disease of the ascending aorta or patients with a low ejection fraction to avoid aortic cross-clamping.