Yasunori Kawanishi

Olmesartan ameliorates myocardial function independent of blood pressure control in patients with mild-to-moderate hypertension

Angiotensin II receptor blockers (ARBs) are suggested to be protective against myocardial hypertrophy and fibrosis, although such beneficial effects remain to be elucidated in the human heart. The aim of the present study was to examine the effect of a novel ARB, olmesartan, on myocardial function of the left ventricle in patients with mildto-moderate hypertension. We investigated 10 patients (6 men and 4 women, 62 ± 7 years of age) who were stable with a single regimen of amlodipine, which was switched to olmesartan. Before and 8 months after changing medications, patients underwent echocardiographic examination and blood sampling, including measurement of the plasma high-sensitivity C-reactive protein (hsCRP) level. Peak velocities at the mitral annulus were determined by tissue Doppler imaging and used as measures of myocardial function. Olmesartan did not significantly alter blood pressure (BP) (systolic BP, 122 ± 12 to 121 ± 8 mmHg, P = 0.9; diastolic BP, 79 ± 6 to 75 ± 4 mmHg, P = 0.06) or parameters of global left ventricular systolic and diastolic function. Tissue Doppler imaging, however, revealed significant increases in the systolic (8.2 ± 1.3 to 8.9 ± 1.1 cm/s, P < 0.01) and early diastolic (6.7 ± 0.9 to 7.6 ± 1.0 cm/s, P = 0.02) velocities at the mitral annulus. This was associated with decreases in the left ventricular mass index (83 ± 15 to 73 ± 19 g/m2, P = 0.09) and hsCRP (683 ± 555 to 655 ± 450 ng/ml, P = 0.07). In conclusion, olmesartan improves myocardial function independent of BP reduction in hypertensive patients. Attenuated inflammatory changes as well as myocardial hypertrophy may play an important role.

Usefulness of Carvedilol to Abolish Myocardial Postsystolic Shortening in Patients With Idiopathic Dilated Cardiomyopathy

Postsystolic shortening (PSS), a positive myocardial velocity after aortic valve closure as assessed by Doppler tissue imaging, is a common pathologic finding in patients with myocardial disease. Beta-blocker therapy can improve global and regional myocardial function. The aim of the present study was to examine whether the beta-blocker carvedilol might reduce the incidence and magnitude of PSS in patients with idiopathic dilated cardiomyopathy. Before and 2 months after carvedilol therapy, 19 patients (7 men, 12 women; mean age 59 +/- 13 years) underwent conventional echocardiographic assessment and Doppler tissue imaging. Time-velocity curves were constructed at the 12 basal and mid myocardial segments of the left ventricular (LV) walls. PSS was defined if positive myocardial velocity after aortic valve closure was greater than the ejection peak. The number of segments showing PSS was assessed before and after carvedilol therapy. Carvedilol decreased LV end-diastolic dimension (from 66 +/- 5 to 62 +/- 7 mm, p <0.01), increased the LV ejection fraction (from 28 +/- 9% to 36 +/- 8%, p <0.01), and increased early diastolic mitral annular velocity (Ea) (from 5.0 +/- 1.6 to 5.5 +/- 1.7 cm/ms, p <0.01). This was associated with significant reductions in the number of segments showing PSS (from 2.8 +/- 3.0 to 0.8 +/- 1.4, p <0.01). There was a correlation between changes in the number of segments showing PSS and changes in Ea (r = -0.56, p = 0.01). In conclusion, PSS may reflect the severity of LV diastolic function during pharmacologic reverse remodeling in patients with idiopathic dilated cardiomyopathy. These data provide new insights into the mechanisms by which carvedilol improves cardiac function and symptoms in these patients.

A Display of Combined Left Ventricular Function and Dyssynchrony Using Doppler Tissue Imaging: Its Application in Acute Response to Cardiac Resynchronization Therapy

Background: We have recently proposed a novel method for displaying left ventricular (LV) function and mechanical dyssynchrony, which is based on the “vector analysis” using Doppler tissue imaging (DTI). The aim of this study was to examine acute‐phase impact of cardiac resynchronization therapy (CRT) on the parameters assessed by this method. Methods: We studied a total of 25 patients with systolic heart failure, 14 undergoing simultaneous acute pacing‐hemodynamic study and DTI; and 11 patients DTI within a few days before and one week after CRT. Parameters derived from the displaying method were followings: (1) percentage area of the hexagon, the area divided by the overall graph area, reflecting global LV systolic function; (2) net‐delay magnitude, the length of the composite vector for the six vectors, a dyssynchrony index; and (3) delayed contraction site, graphical position of the composite vector. Results: CRT significantly increased cardiac output (3.1 ± 1.0 to 3.4 ± 0.7 L/min, P = 0.02) and +dp/dt (782 ± 149 to 1,089 ± 270 mm Hg/s, P < 0.01), and decreased mitral regurgitaion jet area (7.9 ± 3.0 to 4.8 ± 2.4 cm2, P < 0.01). As with the new method, there were significant decreases in the percentage area of the hexagon (20.7 ± 6.6 to 18.6 ± 6.5%, P < 0.01) and the net‐delay magnitude (122 ± 59 to 72 ± 48 ms, P < 0.01). The reduction of net‐delay magnitude accompanied alteration of delayed contraction site; 16 patients had the most delayed site between the lateral and inferior segments before CRT, and seven patients after CRT (P = 0.02). Conclusions: The new method would be a useful tool to assess efficacy of CRT in patients with systolic heart failure. (Echocardiography 2011;28:870‐876)