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Systolic dysfunction and blood pressure responses to supine exercise in patients with hypertrophic cardiomyopathy
1Second Department of Internal Medicine, School of Medicine, Kanazawa University, Japan. shimizu@med.kanazawa-u.ac.jp
Insights
Patients with hypertrophic cardiomyopathy (HCM) may experience exercise-induced systolic dysfunction. This dysfunction is linked to abnormal systolic blood pressure responses during exercise in HCM patients.
Area of Science:
- Cardiology
- Exercise Physiology
- Medical Imaging
Background:
- Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease.
- Non-obstructive HCM affects left ventricular function and blood pressure regulation.
- Exercise capacity is often limited in HCM patients.
Purpose of the Study:
- To investigate left ventricular function and blood pressure responses during exercise in non-obstructive HCM.
- To compare these responses between HCM patients with and without exercise-induced ejection fraction decline and healthy controls.
Main Methods:
- Utilized radionuclide ventricular function monitoring during supine ergometer exercise.
- Evaluated 56 patients with non-obstructive HCM and 12 healthy controls.
- Divided HCM patients into two groups based on ejection fraction (EF) changes during exercise.
Main Results:
- End-systolic volume changes differed significantly between groups during exercise (p<0.0001).
- Systolic blood pressure (SBP) changes also varied significantly across groups.
- Group B (decreased EF) showed smaller SBP increases compared to controls and Group A (no EF decrease).
- A significant correlation was found between changes in EF and SBP from rest to peak exercise (p<0.005).
Conclusions:
- Exercise-induced systolic dysfunction in non-obstructive HCM may be associated with abnormal blood pressure responses.
- Radionuclide assessment can reveal exercise-related functional changes in HCM.
- Understanding these responses is crucial for managing HCM patients.
Abstract:
Left ventricular function and blood pressure responses were evaluated in 56 patients with non-obstructive hypertrophic cardiomyopathy (HCM) and 12 control subjects by using a radionuclide ventricular function monitor during supine ergometer exercise. Patients with HCM were divided into 2 groups: (i) group A had no decrease in ejection fraction (EF) during exercise; and (ii) group B had a decrease in EF during exercise. During exercise, the change in end-diastolic volume did not differ between the 3 groups. In contrast, the change in end-systolic volume differed between the 3 groups (p<0.0001). The change in systolic blood pressure (SBP) also differed significantly between the 3 groups. The change in SBP in group B was smaller than that in the control group and group A, and changes in the EF and changes in the SBP between rest and peak exercise showed a significant correlation (p<0.005). These results suggest that exercise-induced systolic dysfunction in patients with non-obstructive HCM may contribute to abnormal blood pressure response in those patients.