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Relationships between left ventricular mass and clinical, biohumoral and hemodynamic parameters in human hypertension
Insights
Elevated adrenergic tone may contribute to left ventricular hypertrophy in hypertension. This study found a significant link between beta-adrenoceptor responsiveness and 24-hour urinary catecholamines in hypertensive patients, suggesting a role for sympathetic nervous system activity.
Area of Science:
- Cardiology
- Hypertension Research
- Physiology
Background:
- Left ventricular hypertrophy (LVH) is a common complication of hypertension.
- The underlying mechanisms contributing to LVH in hypertensive individuals require further elucidation.
- The role of adrenergic tone in the development of LVH is not fully understood.
Purpose of the Study:
- To investigate the relationship between left ventricular mass (LVM) and biohumoral/hemodynamic parameters in hypertensive patients.
- To explore the correlation between beta-adrenoceptor responsiveness and catecholamine levels in relation to LVM.
- To determine if adrenergic tone plays a permissive role in the development of LVH in human hypertension.
Main Methods:
- Echocardiography was used to assess LVM in 63 mild/moderate hypertensive patients and 23 normotensive controls.
- Beta-adrenoceptor responsiveness was evaluated by the chronotropic response to isoproterenol (CD25).
- 24-hour urinary catecholamine output was measured, and correlations with LVM and other parameters were analyzed.
Main Results:
- In hypertensive patients, LVM index significantly correlated with CD25 (r=0.525) and urinary catecholamines (r=0.485).
- CD25 and urinary catecholamines were significantly higher in hypertensives compared to normotensives.
- Left ventricular wall thickness also correlated with CD25 and urinary catecholamines exclusively in hypertensive patients.
Conclusions:
- Elevated adrenergic tone, indicated by increased beta-adrenoceptor responsiveness and catecholamine levels, is associated with increased LVM in hypertension.
- These findings support the hypothesis that heightened sympathetic nervous system activity may facilitate the development of left ventricular hypertrophy in hypertensive individuals.
- Further research into modulating adrenergic tone could offer therapeutic strategies for preventing or treating hypertensive cardiac remodeling.
Abstract:
The relationships between left ventricular mass (LVM), assessed by echocardiography, and several biohumoral and hemodynamic parameters were studied in 63 mild or moderate hypertensive patients and in an age-matched group of 23 normotensive subjects. In hypertensive patients, but not in normotensives, LVM index was significantly correlated with beta-adrenoceptor responsiveness, as evaluated by the chronotropic response to isoproterenol ( CD25 ) (r = 0.525, p less than 0.001) and with the 24-hour catecholamine urinary output (r = 0.485, p less than 0.001). Both CD25 and the catecholamine urinary output were significantly higher in the hypertensives as compared with the normotensive subjects. Moreover, left ventricular wall thickness (septum + posterior wall) was significantly correlated with CD25 and urinary catecholamines only in hypertensive patients. No significant correlation was found between LVM or wall thickness and body surface area, age, blood pressure, heart rate, cardiac output, total peripheral resistance and left ventricular systolic wall stress, whereas CD25 was correlated with urinary catecholamines only in hypertensive patients (r = 0.606, p less than 0.001). These results seem to support the hypothesis that an elevated adrenergic tone may exert a permissive role in the development of left ventricular hypertrophy in human hypertension.