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Decreased left ventricular contractility reserve in patients with never-treated essential hypertension
M Tanaka1, Y Hashimoto, F Numano
1Department of Internal Medicine, Sanraku Hospital, Tokyo, Japan. tane.med3@med.tmd.ac.jp
Insights
Essential hypertension patients show reduced systolic function reserve during beta-adrenoceptor activation. This indicates impaired left ventricular contractile reserve beyond diastolic dysfunction in hypertensive individuals.
Area of Science:
- Cardiology
- Hypertension Research
- Echocardiography
Background:
- Left ventricular diastolic dysfunction is common in essential hypertension.
- Systolic function reserve in hypertensive patients requires further evaluation.
- Untreated essential hypertension can affect cardiac mechanics.
Purpose of the Study:
- To assess global left ventricular contractile reserve in untreated essential hypertension patients.
- To determine if systolic function is normal or subnormal under stress.
- To investigate the impact of concentric left ventricular remodeling on systolic function.
Main Methods:
- Evaluated 31 untreated hypertensive men and 12 healthy normotensive men.
- Divided hypertensives into groups based on concentric remodeling (relative wall thickness >= 0.45).
- Assessed left ventricular function using echocardiography during dobutamine infusion (beta-adrenoceptor activation).
Main Results:
- During dobutamine infusion, endocardial fractional shortening (eFS) was lower in hypertensive groups (Hc, Hn) compared to normotensive controls (N).
- eFS correlated with end-systolic wall stress (ESS); 52% of Hc group showed impaired eFS-ESS relationship.
- Diastolic function parameters (E, E/A) were significantly lower in the Hc group compared to N and Hn groups.
Conclusions:
- Patients with essential hypertension exhibit decreased systolic function reserve under beta-adrenoceptor activation.
- This impairment in contractile reserve occurs in addition to known diastolic dysfunction.
- Concentric left ventricular remodeling may be associated with more pronounced systolic dysfunction.
Abstract:
1. Left ventricular diastolic dysfunction is often present in patients with essential hypertension. To determine whether left ventricular systolic function is normal or subnormal, we evaluated the global left ventricular contractile reserve in patients with untreated essential hypertension. 2. Thirty-one untreated men with essential hypertension and 12 normotensive healthy men were evaluated. Hypertensives were divided into two groups based on the presence (group Hc; n = 21) or absence (group Hn; n = 10) of concentric left ventricular geometric remodelling, which was defined as a relative wall thickness > or = 0.45 on M-mode echocardiography. We compared echocardiographic data of left ventricular function in hypertensive men with those in healthy men under beta-adrenoreceptor activation by up to 10 microg/kg per min dobutamine infusion. 3. At baseline, endocardial (eFS) and midwall fractional shortening of the left ventricle, the early peak filling velocity (E), the peak late filling velocity (A) and the ratio E/A were similar in the three groups. During dobutamine infusion, eFS was significantly lower in groups Hc and Hn (54.1+/-9.2 and 54.1+/-7.9%, respectively) than that observed in group N (61.7+/-7.4%). In addition, eFS was highly correlated with circumferential end-systolic wall stress (ESS) during dobutamine infusion in the three groups. In 11 subjects in group Hc (52%), the eFS-ESS relationship was lower than the 95% confidence limit of the normal regression. Comparing group Hc with groups N and Hn, it was found that E (0.52+/-0.12, 0.71+/-0.16 and 0.63+/-0.15 m/s, respectively) and E/A (0.74+/-0.23, 1.24+/-0.53 and 0.98+/-0.37, respectively) were significantly lower. 4. Our results suggest that, in addition to diastolic dysfunction, the reserve of systolic function decreased under beta-adrenoceptor activation in patients with essential hypertension.