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Neurohormonal activity and left ventricular geometry in patients with essential arterial hypertension
M W Muscholl1, H Schunkert, F Muders
1Department of Cardiology, University of Regensburg, Germany.
Insights
This study found that elevated renin and atrial natriuretic peptide (ANP) levels are linked to increased left ventricular (LV) mass in hypertensive patients. ANP and aldosterone correlate with specific LV geometry patterns, suggesting their role in hypertensive heart changes.
Area of Science:
- Cardiology
- Hypertension Research
- Endocrinology
Background:
- Left ventricular (LV) geometry in hypertension is influenced by growth factors like pressure overload and humoral activation.
- Understanding the relationship between neurohormonal systems and LV structural changes is crucial for managing hypertensive heart disease.
Purpose of the Study:
- To investigate the association between basal activity of the renin-angiotensin-aldosterone system (RAAS) and atrial natriuretic peptide (ANP) levels with specific left ventricular (LV) geometry patterns in essential hypertension.
- To determine if RAAS and ANP are independently related to LV mass and geometry in hypertensive individuals.
Main Methods:
- Echocardiography was used to assess LV geometry in 104 patients with essential hypertension and 104 controls.
- Plasma renin activity (PRA), serum aldosterone, and ANP levels were measured using radioimmunoassay.
- Correlation and multivariate analyses were performed to identify associations between hormonal levels and LV parameters.
Main Results:
- Plasma renin activity (PRA) was associated with septal wall thickness and LV mass index, and elevated in concentric LV hypertrophy.
- Aldosterone levels correlated with ventricular wall thickness and were elevated in patients with LV remodeling and hypertrophy.
- Atrial natriuretic peptide (ANP) showed associations with LV dimensions and mass index, and was significantly increased in hypertensive patients with concentric and eccentric LV hypertrophy.
Conclusions:
- Elevated renin and ANP levels are associated with increased LV mass index in hypertensive patients.
- ANP and aldosterone levels are specifically related to distinct geometric patterns of the left ventricle in hypertension.
- These findings highlight the role of neurohormonal factors in modulating LV geometry alterations in essential hypertension.
Abstract:
The purpose of this study was to investigate whether the basal activity of the renin-angiotensin-aldosterone system or the basal levels of the atrial natriuretic peptide (ANP) are related to distinct patterns of left ventricular (LV) geometry in patients with essential hypertension. The left ventricle of patients with arterial hypertension may be exposed to a variety of growth-regulating mechanisms, including pressure overload and humoral activation. The interaction of such growth stimuli may be involved in the modulation of LV geometry. LV geometry was determined echocardiographically in 104 patients with mild to moderate essential hypertension. The same number of age- and sex-matched normotensive subjects served as controls. Plasma renin activity (PRA) and serum concentrations of aldosterone and ANP were measured by radioimmunoassay. Correlation analyses revealed that PRA was significantly associated with septal wall thickness and LV mass index (r = 0.25; p < 0.005 each). In addition, as compared with normal subjects (1.0 +/- 0.7 ng/ml/hr), PRA was significantly increased in patients with concentric LV hypertrophy (LVH) (3.4 +/- 6.6 ng/ml/hr, p < 0.01). Aldosterone displayed a close correlation with septal, posterior, and relative wall thickness (r > 0.27, p < 0.005 each). Compared with normal subjects (74 +/- 27 pg/ml), patients with hypertension and pathologic patterns of LV geometry were characterized by elevations of aldosterone (LV remodeling 203 +/- 93 pg/ml, concentric LVH 123 +/- 67 pg/ml; eccentric LVH 199 +/- 89 pg/ml; p < 0.05 each). ANP was significantly associated with septal wall thickness, left ventricular dimension, and LV mass index (r > 0.22, p < 0.005 each). Furthermore, compared with normal subjects (50 +/- 17 pg/ml), ANP values were significantly increased in patients with hypertension and concentric LVH (80 +/- 44 pg/ml, p < 0.005) and eccentric LVH (88 +/- 24 pg/ml, p < 0.001). Multivariate analysis adjusting for systolic blood pressure, body mass index, and age revealed that renin and ANP were independently associated with LV mass index (p < 0.05 each). Interestingly, adjusted PRA levels were not related to any specific pattern of LV geometry. In contrast, adjusted ANP levels were associated with concentric and eccentric LVH, whereas adjusted aldosterone levels were significantly elevated in subjects with LV remodeling and eccentric LVH (p < 0.005). Thus elevated levels of renin and ANP may be found in patients with hypertension and elevated LV mass index. In addition, ANP and aldosterone are related to specific geometric patterns of the left ventricle. The data may further stimulate the discussion on the mechanisms that account for alterations of LV geometry in hypertension.