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Exercise performance in patients with hypertension. Relation to electrocardiographic criteria for left ventricular
1Division of Cardiology, Case Western Reserve University School of Medicine, Cleveland, Ohio.
Insights
Electrocardiographic left ventricular hypertrophy (LVH) in hypertensive patients significantly impairs exercise capacity. This ECG-defined LVH, indicated by P and T wave changes, is linked to reduced exercise duration, even without prior heart attack.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Hypertension is a major risk factor for cardiovascular disease.
- Left ventricular hypertrophy (LVH) is a common complication of hypertension.
- The impact of ECG-diagnosed LVH on exercise performance in hypertensive individuals requires further elucidation.
Purpose of the Study:
- To investigate the influence of electrocardiographic left ventricular hypertrophy (ECG-LVH) on exercise capacity in hypertensive patients.
- To compare exercise performance between hypertensive patients with and without ECG-LVH and with healthy controls.
Main Methods:
- A cohort of 101 hypertensive patients and 37 control subjects underwent maximal treadmill exercise testing.
- Left ventricular hypertrophy was diagnosed using the Romhilt-Estes point score system.
- Exercise capacity was quantified by symptom-limited treadmill test duration using the modified Bruce protocol.
Main Results:
- Hypertensive patients without LVH demonstrated reduced exercise duration compared to controls (p < 0.01).
- Hypertensive patients with ECG-LVH exhibited significantly shorter exercise duration than those without LVH (p < 0.01).
- Multivariate analysis identified age, gender, systolic blood pressure, and ECG point score as independent predictors of exercise duration (R2 = 0.48, p < 0.0001).
Conclusions:
- Electrocardiographic evidence of LVH is associated with impaired exercise capacity in hypertensive patients.
- P wave and T wave abnormalities indicative of LVH correlate with reduced exercise duration.
- ECG-LVH negatively impacts exercise performance in hypertensive individuals, independent of prior myocardial infarction.
Abstract:
The influence of the electrocardiographic diagnosis of left ventricular hypertrophy on exercise performance was assessed in 101 hypertensive patients and 37 control subjects referred to an exercise testing laboratory. Maximal exercise capacity was measured by the duration of a symptom-limited, treadmill test using the modified Bruce protocol. The Romhilt-Estes point score system, as modified by Murphy, was used to define left ventricular hypertrophy by electrocardiographic criteria. After adjusting for age differences between hypertensive and control subjects, the hypertensive group without left ventricular hypertrophy had a shorter exercise duration than the control group (13.0 +/- 3.0 vs. 15.3 +/- 2.5 min, respectively; p less than 0.01). The 16 hypertensive patients with electrocardiographic evidence of hypertrophy had a shorter exercise duration than those without (10.9 +/- 2.0 vs. 13.0 +/- 3.0 min, respectively; p less than 0.01). Multivariate regression analysis indicated that age, gender, systolic blood pressure, and electrocardiographic point score were all significant independent variables in predicting exercise duration (R2 = 0.48, p less than 0.0001). Exercise duration was unrelated to QRS amplitude. The authors conclude that electrocardiographic evidence of left ventricular hypertrophy, as manifested by P wave and T wave abnormalities, is associated with an impaired exercise capacity in a hypertensive population without prior myocardial infarction.