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Autonomic cardiovascular control and diastolic dysfunction in hypertensive subjects
Gianfranco Piccirillo1, Giuseppe Germanò, Antonio Vitarelli
1Dipartimento di Scienze dell'Invecchiamento, Policlinico Umberto I, Università La Sapienza, Rome, Italy. gianfranco.piccirillo@uniroma1.it
International Journal of Cardiology
|July 30, 2005
Summary
Newly diagnosed hypertension, especially with diastolic dysfunction, shows increased sympathetic nervous system activity. This suggests heightened sympathetic modulation of the sinus node in hypertensive individuals.
Area of Science:
- Cardiology
- Autonomic Nervous System Research
- Hypertension Studies
Background:
- Early hypertension is linked to left ventricular diastolic dysfunction, potentially affecting autonomic control of the cardiovascular system.
- Increased end-diastolic pressure in hypertension may trigger cardiopulmonary reflexes influencing autonomic function.
Purpose of the Study:
- To investigate autonomic nervous system modulation in recently diagnosed hypertension.
- To compare autonomic control in hypertensive patients with and without diastolic dysfunction.
Main Methods:
- Power spectral analysis of RR interval and systolic arterial pressure variability was used.
- Subjects included normotensive controls and hypertensive patients with or without diastolic dysfunction.
Main Results:
- Hypertensive groups exhibited higher low-frequency (LF) power in normalized units (NUs) at rest compared to controls.
- Hypertensive subjects with diastolic dysfunction showed a greater LF spectral index after tilt compared to those without.
- LF NUs correlated with echocardiographic measures of diastolic function (E/A ratio and E-wave deceleration time).
Conclusions:
- Sympathetic modulation of the sinus node appears dominant in recently diagnosed hypertension.
- Hypertensive individuals with diastolic dysfunction may experience greater sympathetic sinus node modulation during orthostatic stress (tilt test).