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Supernormal left ventricular performance in young subjects with mild hypertension: an alerting response to the
P Palatini1, P Visentin, G Nicolosi
1Clinica Medica I, University of Padova, Italy.
Insights
Supernormal left ventricular function in early hypertension may be a false indicator. This heightened cardiac performance is linked to the alerting response during examinations, not underlying sympathetic nervous system changes.
Area of Science:
- Cardiology
- Hypertension Research
- Echocardiography
Background:
- Early hypertension is characterized by changes in cardiac function.
- Supernormal left ventricular systolic function is observed in a subset of hypertensive individuals.
- The clinical significance of this supernormal function remains unclear.
Purpose of the Study:
- To investigate the clinical significance of supernormal left ventricular systolic function in never-treated borderline to mild hypertensive subjects.
- To differentiate between true cardiac adaptation and examination-induced responses.
Main Methods:
- Studied 635 never-treated hypertensive subjects (18-45 years old).
- Utilized echocardiography, 24-hour ambulatory blood pressure monitoring, and 24-hour urine catecholamine analysis.
- Defined supernormal function based on the left ventricular shortening-stress relationship compared to normotensive controls.
Main Results:
- Subjects with supernormal function exhibited higher office systolic blood pressure, heart rate, and cardiac index.
- No significant differences were found in 24-hour blood pressure, heart rate, or catecholamine output.
- Age, hypertension duration, and left ventricular mass were similar between groups.
Conclusions:
- Supernormal left ventricular pump function in early hypertension appears to be a marker of the alerting reaction to the examination.
- It does not reflect increased baseline sympathetic tone.
- Further research is needed to understand the long-term implications.
Abstract:
1. To assess the clinical significance of supernormal left ventricular systolic function in the initial phase of hypertension, 635 never-treated 18-45-year-old borderline to mild hypertensive subjects (477 males, 158 females) were studied. All subjects underwent echocardiography, 24 h ambulatory blood pressure monitoring and 24 h urine collection for catecholamine dosage. 2. Subjects whose left ventricular shortening-stress relationship was above the 95% confidence intervals of 50 normotensive subjects of similar age and sex distribution were defined as having supernormal function. 3. Age, duration of hypertension and left ventricular mass were similar in the hypertensive subjects with normal (85%) and supernormal (15%) ejective performance. Subjects with supernormal function showed higher office systolic blood pressure (P < 0001), office heart rate (P = 0.03) and cardiac index (P < 0001). Conversely, 24 h systolic blood pressure, 24 h heart rate and 24 h catecholamine output did not differ according to left ventricular function. 4. In conclusion, the greater white-coat effect and the normal baseline sympathetic tone exhibited by the patients with increased performance suggest that supernormal left ventricular pump function is only a marker of the alerting reaction elicited by the echocardiographic examination.