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The influence of exercise on left ventricular outflow tract obstruction, left ventricular performance and
Insights
Exertional exercise can cause or worsen left ventricular outflow tract obstruction in hypertrophic cardiomyopathy (HCM) patients. T-wave inversions may lessen during exercise, indicating improved left ventricular function.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Hypertrophic cardiomyopathy (HCM) is a complex heart condition.
- Understanding exertional hemodynamics in HCM is crucial for patient management.
Purpose of the Study:
- To evaluate the impact of exercise on left ventricular (LV) outflow tract obstruction and ECG changes in HCM patients.
- To investigate the relationship between systolic anterior movement (SAM) of the mitral valve and exercise in HCM.
Main Methods:
- Echocardiography and electrocardiography (ECG) were performed on 42 HCM patients during supine ergometer exercise.
- Patients were categorized based on the presence and exercise-induced changes in LV outflow tract obstruction and SAM.
Main Results:
- Exertional exercise induced or intensified LV outflow tract obstruction and SAM in a significant subset of HCM patients.
- Inverted T-waves observed at rest in some HCM patients tended to become less deep during exercise, correlating with increased LV wall motion.
Conclusions:
- Exercise can precipitate or exacerbate LV outflow tract obstruction in hypertrophic cardiomyopathy.
- Exercise-induced changes in HCM may include reduced T-wave inversion and enhanced LV function.
Abstract:
To investigate exertional changes in hypertrophic cardiomyopathy (HCM), 42 patients with HCM were studied by echocardiography and ECG at a supine ergometer exercise. In 12 cases with left ventricular (LV) outflow tract obstruction at rest (Group I), systolic anterior movement (SAM) of mitral valve was intensified during exercise; and among 30 cases without obstruction at rest (Group II), in 6 cases (Group IIA) SAM appeared during exercise. SAM might be further intensified 1 minute after exercise. Inverted T-wave was seen at rest especially in Group IIB (no SAM both at rest and during exercise), and tended to become less deep during exercise with an increase of LV wall motion. In conclusion, in HCM, LV outflow tract obstruction may be produced or intensified during exercise. Inverted T-wave in HCM may become less deep during exercise, with accelerated LV function.