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[Determinant of cardiac hypertrophy in elderly hypertension]
A Kawamoto1, K Shimada, K Matsubayashi
1Department of Medicine and Geriatrics, Kochi Medical School.
Insights
In elderly hypertension, elevated blood pressure, not hormonal factors, drives cardiac hypertrophy. This suggests hemodynamic changes are key in older adults, unlike younger hypertensive patients.
Area of Science:
- Cardiology
- Gerontology
- Hypertension Research
Background:
- Cardiac hypertrophy is a common adaptation to hypertension.
- The specific factors driving cardiac hypertrophy in elderly hypertensive individuals remain unclear.
- Previous research suggests hormonal and neural systems influence cardiac adaptation in younger hypertensives.
Purpose of the Study:
- To identify factors contributing to cardiac hypertrophy in elderly hypertensive patients.
- To compare determinants of left ventricular mass (LVM) between elderly hypertensives and normotensives.
- To investigate the role of hemodynamic and non-hemodynamic factors in cardiac remodeling in the elderly.
Main Methods:
- Correlated echocardiographic left ventricular mass (LVM) with blood pressure and humoral parameters.
- Included 30 elderly hypertensive patients and 30 age-matched normotensive controls (mean age 65).
- Utilized clinic, exercise, and 24-hour ambulatory blood pressure monitoring; measured plasma norepinephrine, renin activity, and atrial natriuretic factor.
Main Results:
- Elderly hypertensives showed increased interventricular septum and posterior wall thickness compared to normotensives.
- LVM strongly correlated with all measured blood pressure parameters, especially mean ambulatory systolic blood pressure (r=0.65).
- Plasma norepinephrine, renin activity, and atrial natriuretic factor showed no significant correlation with LVM in this elderly cohort.
Conclusions:
- Cardiac hypertrophy in elderly hypertension is primarily concentric and driven by hemodynamic factors (blood pressure).
- Unlike younger populations, the sympathetic nervous system and renin-angiotensin system do not appear to be significant determinants of cardiac hypertrophy in the elderly.
- These findings highlight age-specific mechanisms in hypertensive cardiac remodeling.
Abstract:
In order to define the factors responsible for cardiac hypertrophy in elderly hypertension, blood pressures and non-hemodynamic humoral parameters were correlated with echocardiographic left ventricular mass (LVM) in 30 elderly hypertensive patients and 30 age-matched normotensive subjects with a mean age of 65 years. Arterial blood pressures were obtained either at the clinic, after supine rest, during maximal exercise test, or with a 24 hour ambulatory monitoring device at 10 minute intervals. Interventricular septum and posterior wall thickness, but not end-diastolic diameter, were significantly increased in the hypertensives than in the normotensives. LVM was significantly correlated with all of te blood pressure parameters, having the strongest association with the mean of ambulatory systolic blood pressures (r = 0.65, p less than 0.001). On the other hand, plasma norepinephrine (r = 0.09), plasma renin activity (r = -0.14), and atrial natriuretic factor (r = -0.08), though known to influence cardiac adaptation to hypertrophy in young or middle aged hypertensives, were not correlated wit LVM. These results suggest that the heart in elderly hypertension is characterized by concentric hypertrophy, the only significant determinant of which appears to be a hemodynamic factor. Unlike younger patients, sympathetic nervous and renin-angiotensin systems may not play an important role in the development of cardiac hypertrophy in the elderly.