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[Effect of heart rate on cardiac hemodynamics in patients with aortic regurgitation]
T Nakamura1, S Nezuo, T Sawayama
1Department of Medicine, Kawasaki Medical School.
Insights
In severe aortic regurgitation (AR), increasing heart rate up to 100 beats per minute improves cardiac function and hemodynamics. However, further increases in heart rate beyond this point can worsen these parameters.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Context:
- Aortic regurgitation (AR) is a significant valvular heart disease.
- Understanding the impact of heart rate on cardiac hemodynamics in AR is crucial for patient management.
Purpose:
- To investigate the effects of varying heart rates on cardiac hemodynamics in patients with severe aortic regurgitation.
- To determine the optimal heart rate range for improved cardiac function in this patient population.
Summary:
- Hemodynamic parameters, including regurgitant fraction and total systemic resistance, were assessed in 10 AR patients using right atrial pacing at heart rates of 80, 100, 120, and 140 bpm.
- Improvements in cardiac function, regurgitant fraction, and systemic resistance were observed up to a heart rate of 100 bpm.
- Beyond 100 bpm, these hemodynamic parameters and overall cardiac function deteriorated, as evidenced by changes in the cardiac function curve and LV end-diastolic pressure-volume relation.
Impact:
- Findings suggest that maintaining a heart rate around 100 bpm may be beneficial for patients with severe aortic regurgitation.
- This study provides insights into heart rate optimization strategies for managing severe AR.
- Results highlight the potential risks of excessively high heart rates in severe AR patients.
Abstract:
We evaluated the effects of heart rate on cardiac hemodynamics in 10 patients with aortic regurgitation (AR, mean regurgitant fraction: 64.3%). Cardiac catheterization was performed in all patients, and the hemodynamic parameters were obtained by increasing heart rate (80.100.120.140) using right atrial pacing. Regurgitant fraction and total systemic resistance were improved up to 100/min, but aggravated on further increase in heart rate. Cardiac function curve was remarkably improved up to 100/min, but aggravated on further increase in heart rate. LV end-diastolic pressure-volume relation was moved toward the left lower direction up to 100/min, but toward the left upper direction on further increase in heart rate. Thus, it was concluded that in severe AR, cardiac function was improved up to 100/min, but aggravated on further increase in heart rate.