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Hemodynamic benefits of verapamil after aortic reconstruction
M S Dahn1, R F Wilson, M P Lange
1Department of Surgery, Veterans Administration Medical Center, Detroit, MI.
Insights
Verapamil effectively reduced heart rate and pressure-rate product after aortic surgery, particularly in patients with coronary artery disease. This intervention helps manage myocardial oxygen demand without compromising cardiac function.
Area of Science:
- Cardiology
- Cardiac Surgery
- Pharmacology
Background:
- Coronary artery disease (CAD) is common in patients undergoing aortic surgery.
- Myocardial oxygen consumption is linked to blood pressure and heart rate (HR), forming the pressure-rate product.
- Postoperative management aims to prevent increases in these parameters to reduce cardiac strain.
Purpose of the Study:
- To evaluate the effect of verapamil, a calcium channel antagonist, on postoperative heart rate and pressure-rate product in patients undergoing abdominal aortic reconstruction.
- To determine if verapamil can mitigate increases in myocardial oxygen demand after aortic surgery.
Main Methods:
- A study involving 30 patients undergoing abdominal aortic reconstruction.
- Patients were divided into groups with and without coronary artery disease (CAD).
- Postoperative heart rate and blood pressure were monitored, and the pressure-rate product was calculated. Verapamil's effect was assessed.
Main Results:
- Postoperative HR increased significantly more in patients with CAD (47%) compared to those without (27%).
- Pressure-rate product also increased substantially, particularly in the CAD group (31%).
- Verapamil significantly reduced HR and pressure-rate product in patients with CAD by 13% and 18%, respectively, without affecting cardiac output or ejection fraction.
Conclusions:
- Postoperative increases in myocardial oxygen demand after aortic surgery are primarily driven by elevated heart rate.
- Verapamil is effective in reducing these increases, especially in patients with CAD.
- Verapamil administration can help manage myocardial oxygen demand post-aortic surgery without adverse effects on cardiac function.
Abstract:
Because of the high incidence of coronary artery disease (CAD) in patients undergoing aortic surgery, and because myocardial oxygen consumption is proportional to blood pressure x heart rate (HR) (pressure-rate product), it is important to prevent increases in these parameters postoperatively. The effect of verapamil, a calcium channel antagonist, on these parameters was evaluated in 30 patients undergoing abdominal aortic reconstruction. Postoperatively HR increased 27% in 19 patients without CAD and 47% in 11 patients with CAD. Pressure-rate product (blood pressure x HR) increased 17% and 31% in these two groups, respectively. Verapamil was able to reduce postoperative HR by 3% in patients without CAD and by 13% in patients with CAD. Verapamil reduced pressure-rate product 8% and 18%, respectively, in the two groups. These reductions were statistically significant in patients with CAD and occurred without reductions in cardiac output or left ventricular ejection fraction. Thus the postoperative increases in myocardial oxygen demand appeared to be primarily related to increased HR after aortic surgery, and these were reduced by verapamil without impairing blood flow or cardiac function.