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Diastolic dysfunction and baroreflex sensitivity in hypertension
M V Pitzalis1, A Passantino, F Massari
1Institute of Cardiology, University of Bari, Division of Cardiology, "S. Maugeri" Foundation, IRCCS, Cassano Murge, Italy. pitzalis@tin.it
Insights
Age and impaired baroreflex heart rate response, not blood pressure, predict diastolic dysfunction in hypertension. Understanding these factors is crucial for managing cardiovascular health in hypertensive patients.
Area of Science:
- Cardiology
- Hypertension Research
- Physiology
Background:
- Diastolic dysfunction in systemic hypertension is not fully understood.
- Identifying key contributing factors is essential for effective patient management.
Purpose of the Study:
- To investigate the roles of age, arterial blood pressure, and baroreflex heart rate response impairment in diastolic dysfunction.
- To determine predictors of diastolic dysfunction in newly diagnosed, untreated hypertensive patients.
Main Methods:
- Studied 61 untreated hypertensive patients using Doppler echocardiography for diastolic dysfunction.
- Assessed arterial blood pressure via 24-hour ambulatory monitoring.
- Evaluated baroreflex heart rate response using spectral analysis (alpha index).
Main Results:
- Age was the strongest predictor of diastolic dysfunction (r=-0.63, P<0.001).
- Patients with diastolic dysfunction showed significantly lower spectral baroreflex gain.
- No significant difference in 24-hour ambulatory blood pressure was observed between groups.
Conclusions:
- Age and impaired baroreflex heart rate response are key determinants of left ventricular diastolic dysfunction.
- Pressure overload (arterial blood pressure) was not identified as a determinant.
- Findings highlight the importance of age and baroreflex function in hypertensive diastolic dysfunction.
Abstract:
The determinants of diastolic dysfunction in patients with systemic hypertension are not completely known. To evaluate the possible role of age, arterial blood pressure, and baroreflex heart rate response impairment in causing diastolic dysfunction, we studied 61 patients (42 male; mean+/-SD age, 43.9+/-12 years) with newly recognized and therefore previously untreated systemic hypertension. Diastolic dysfunction was evaluated by means of Doppler echocardiography (and diagnosed as such when the early to atrial peak velocity ratio corrected to heart rate was <1), arterial blood pressure by 24-hour ambulatory monitoring, and baroreflex heart rate response by means of the spectral technique (alpha index) during paced (0.27 Hz) and spontaneous breathing (in a supine position and during tilt). Nineteen patients had diastolic dysfunction, the most powerful predictor of which was age (r=-0.63, P<0.001). The patients with diastolic dysfunction had significantly lower values for spectral baroreflex gain in the high-frequency band than those without (5.2+/-3 versus 8.4+/-5 ms/mm Hg during paced breathing, P<0.05; 7. 4+/-4 versus 13.3+/-7 ms/mm Hg in a supine position, P<0.05; 4.3+/-4 versus 5+/-2 ms/mm Hg during tilt, P