Abstract
Because the functional interaction between the LV and arterial systems, termed ventricular-arterial coupling, is recognized as a key determinant of LV performance, the objective of the present study was to assess the impact of uncomplicated HT without LVH on LV performance using simultaneously echocardiography and carotid tonometry. LV maximal power (PmaxVG), cardiac power output (CPO), LV efficiency (CPO/PmaxVG), input aortic and output LV elastance (Ea and Ees) were assessed in 20 normotensive control subjects (NT) and 10 patients with untreated HT. PmaxVG was calculated according to the integral of the product of LV wall stress with strain rate (as an index of gradient velocity). Cyclic variation of wall thickness and SR were measured by speckel-tracking. Ea and Ees were derived and modelized from the pressure-volume curve. No difference * Auteur correspondant. Adresse e-mail : benjamin.bonnet@univ-montp2.fr (B. Bonnet). in age, BMI and sex ratio was observed between NT and HT. Systolic BP (160 ± 18 vs. 119 ± 10 mmHg), LV mass (99 ± 15 vs. 76 ± 12 g/m 2), PWV (9.7 ± 2 vs. 6.9 ± 1 m/s) were significantly higher (P < 0.01) in HT when compared to NT. In HT increased of CPO and Ea was compensated by an increase of LV (15 ± 4 vs. 12 ± 3%, P < 0.02) and Ees (5.5 ± 2 vs. 4.5 ± 1.5 mmHg/mL), which are significantly elevated in HT (P < 0.05). No difference was observed in Ea/Ees between NT and HT. In conclusion at the early phase of HT, in patients without LVH, LV performance and ventricular-arterial coupling were adapted to post-load elevation. This adaptation may be the result of an increased of LV contractility.