Norio Nagase

The Functional Role of Longitudinal, Circumferential, and Radial Myocardial Deformation for Regulating the Early Impairment of Left Ventricular Contraction and Relaxation in Patients With Cardiovascular Risk Factors: A Study With Two-Dimensional Strain Imaging

BACKGROUND Two-dimensional strain imaging allows rapid and accurate analysis of regional left ventricular (LV) systolic and diastolic mechanics in the longitudinal, radial, and circumferential directions. The aim of this study was to assess precisely the differences in early impairment of LV myocardial contraction and relaxation among the 3 directions in 70 patients with cardiovascular risk factors and preserved LV pump function. METHODS The patients were classified into 2 groups according to the ratio of early diastolic to atrial systolic velocity (E/A) of transmitral flow: E/A > or = 1 (n = 35, 57 +/- 6.8 years) or E/A < 1 (n = 35, 60 +/- 4.9 years). The longitudinal strain and strain rate curves were determined in apical 2- and 4-chamber views, and radial and circumferential strain and strain rate curves and LV torsion curve were determined in the parasternal short-axis views. RESULTS The mean peak systolic longitudinal strain and strain rate were lower, whereas the mean peak systolic circumferential strain and strain rate were greater in the E/A < 1 group. There were no significant differences in the mean peak systolic radial strain and strain rate between the 2 groups. The mean peak early diastolic longitudinal strain rate was markedly lower in the E/A < 1 group. The mean peak LV strain rates during atrial systole in all 3 directions were greater in the E/A < 1 group. The mean peak LV systolic longitudinal strain and longitudinal strain rate during atrial systole were independent predictors related to E/A in all patients. There were no significant differences in torsion and torsional and untwisting rates between the 2 groups. CONCLUSION LV myocardial contraction and relaxation were first impaired in the longitudinal direction among the 3 directions in subclinical patients with cardiovascular risk factors. However, LV pump function and LV filling were compensated by circumferential shortening at ventricular systole and 3 directional lengthenings at atrial systole, respectively.

A novel approach to assess aortic stiffness related to changes in aging using a two-dimensional strain imaging.

Background: Recently, it has been demonstrated that aortic stiffness is associated with cardiovascular morbidity and mortality. The objective of the present study was to accurately evaluate the aortic stiffness relative to the changes in aging using two‐dimensional (2D) strain imaging in 39 comparatively normal patients (15–85 years). Methods: We obtained short‐axis images of the abdominal aorta (Ao) and determined the peak circumferential strain (Ao‐S) and strain rate (Ao‐SR) and the time from Q‐wave of electrocardiogram to peak Ao‐S using the 2D strain imaging. The stiffness parameters β1 and β2 of the abdominal aorta were measured using M‐mode ultrasonography and 2D strain imaging, respectively. Results: The stiffness parameters β1 and β2 correlated significantly with age (r=0.51, P < 0.001 and r=0.69, P < 0.0001, respectively), particularly the latter parameter β2. The peak circumferential Ao‐S and Ao‐SR correlated strongly with age (r=−0.79, P < 0.0001 and r=−0.87, P < 0.0001, respectively). The stiffness parameter β1 was significantly greater in the old‐aged group (>60 years) than in the young‐aged group (<30 years). The peak circumferential Ao‐S and Ao‐SR were significantly lower in the middle‐aged (30–60 years) and old‐aged groups than in the young‐aged group. Conclusion: The aortic circumferential strain and strain rate measured by 2D strain imaging allow simple and accurate determination of the aortic stiffness.

Early detection of abnormal left atrial-left ventricular-arterial coupling in preclinical patients with cardiovascular risk factors: evaluation by two-dimensional speckle-tracking echocardiography

AIMS Data are lacking on the left atrial (LA)-left ventricular (LV)-arterial coupling for evaluating the functional abnormalities in the left heart disease, whereas LA-LV or LV-arterial coupling has been recognized. This study was designed to earlier detect the abnormal LA-LV-arterial coupling using two-dimensional speckle-tracking echocardiography (2DSTE) in patients with cardiovascular risk factors and no overt cardiovascular disease. METHODS AND RESULTS We studied 30 age-matched healthy individuals and 64 preclinical patients with cardiovascular risk factors, who measured carotid arterial intima-media thickness and stiffness β by M-mode ultrasonography, and strain and strain rate of the LA and LV walls by 2DSTE. The stiffness β and LA volume index (LAVI) were greater in the patient group than in the control group. However, the peak systolic LV longitudinal strain, peak systolic and early diastolic LV longitudinal strain rates, peak systolic and early diastolic LA strains and strain rates, and peak atrial systolic LA strain rate were lower in the patient group. There were correlations between the stiffness β and the age, pulse pressure, LAVI, peak early diastolic LV longitudinal strain rate, and all LA strains and strain rate variables. Multivariate regression analysis indicated that peak early diastolic LV longitudinal strain rate and peak LA strain rate during ventricular systole are defined as strong predictors related to stiffness β. CONCLUSION Impaired LA and LV relaxation in the longitudinal direction are early signs of abnormal LA-LV coupling related to arterial stiffness in preclinical patients with cardiovascular risk factors. 2DSTE enables the quantitative assessment of the LA and LV function, and can be considered a sensitive tool for detecting the abnormal LA-LV-arterial coupling.

Beneficial effects of telmisartan on left ventricular structure and function in patients with hypertension determined by two-dimensional strain imaging.

Background Telmisartan is an angiotensin II receptor blocker with established beneficial effects on cardiac structure and function in animal models. Our aim was to clinically clarify the cardiprotective ability, beyond lowering blood pressure (BP), of telmisartan on left ventricular (LV) myocardial mechanics in patients with hypertension using a two-dimensional (2-D) strain imaging. Methods Telmisartan (20–40 mg daily) was administered to 35 previously untreated patients with hypertension. Conventional and 2-D strain echocardiography were performed after medication had been continued for 1–2 months with values of systolic BP less than 140 mmHg and diastolic BP less than 90 mmHg (phase I) and for 12 months (phase II) in all patients and 30 age-matched normal individuals. Results There were no differences in BP, LV ejection fraction, and ratio of peak early to late diastolic transmitral flow velocity (E/A) between phases I and II of hypertension group and normal group. In phase I, the mean peak systolic strains and strain rates in the longitudinal and circumferential directions, mean peak early diastolic strain rates in the longitudinal, circumferential, and radial directions, and mean peak atrial systolic strain rate in the longitudinal direction were lower than those in the normal group. In phase II, the LV mass index, relative LV wall thickness, isovolumic relaxation time, torsion and torsional rate were decreased, whereas the mean peak systolic strains and early diastolic strain rates in all the three directions, mean peak systolic strain rates in the longitudinal and circumferential directions, and mean peak atrial systolic strain rate in the longitudinal direction were increased compared with phase I. Conclusion The use of telmisartan in patients with hypertension improved not only LV geometric remodeling but also regional LV myocardial contraction and relaxation in the three directions, especially longitudinal and circumferential directions. Our results support beneficial effects on LV structure and function beyond BP reduction from continuous long-term telmisartan therapy.

Vascular aging of common carotid artery and abdominal aorta in clinically normal individuals and preclinical patients with cardiovascular risk factors: diagnostic value of two-dimensional speckle-tracking echocardiography

Increased arterial stiffness is becoming an increasing health care problem as the population ages. Our aim was to detect the vascular aging of common carotid artery (CCA) and abdominal aorta (AAO) more easily and earlier using two-dimensional speckle-tracking echocardiography, and to evaluate the regional differences in mechanical properties related to changes in aging between the two arteries in preclinical patients. Twenty-nine clinically normal individuals and 68 preclinical patients with cardiovascular risk factors were examined. The peak circumferential strains were measured from the short-axis views of the CCA and AAO, and each stiffness β was determined. The CCA and AAO diameters increased with advanced age, and the latter diameter was widely distributed in patients of 50 years or older. The mean strain and stiffness index of the AAO were greater and lower, respectively, than those of the CCA at all ages. The CCA and AAO strains decreased with age, expressing dramatic declines before the fifth decade of life. The CCA and AAO stiffness indices increased with age, expressing rapid ascents after the fifth decade of life, particularly in the AAO. The best markers of subclinical arterial aging were strain in younger persons and stiffness in older individuals. Two-dimensional speckle-tracking echocardiography is a new tool that can be used to directly and easily evaluate arterial function.

Aortic stiffness is strikingly increased with age ≥50 years in clinically normal individuals and preclinical patients with cardiovascular risk factors: Assessment by the new technique of 2D strain echocardiography

BACKGROUND Various measures of aortic stiffness have been proposed as cardiovascular risk markers, but interest has now shifted to more direct and easier evaluation of aortic function. The present study was conducted to determine the feasibility of measuring aortic stiffness (β) with two-dimensional (2D) strain echocardiography and the impact of age and gender on preclinical atherosclerosis. METHODS AND RESULTS The peak circumferential strain of the abdominal aorta was measured using 2D strain echocardiography, and β was determined in 54 clinically normal individuals and 104 patients with cardiovascular risk factors and no evidence of cardiovascular disease. The β correlated significantly with age in all 158 patients. However, the relationship was nonlinear, and β was markedly greater in patients ≥ 50 years. In 54 clinically normal individuals, the relationship was comparatively linear. The systolic blood pressure and pulse pressure were significantly greater in patients ≥ 50 years. There were no significant differences in β and blood pressure parameters between genders. CONCLUSIONS The β increased dramatically with advanced age (≥ 50 years), regardless of gender, in clinically healthy and community-based patients with cardiovascular risk factors. The aortic circumferential strain was measured with 2D strain echocardiography which is a new tool that can be used to directly and easily evaluate aortic stiffness.

Possible mechanisms of left ventricular torsion evaluated by cardioreparative effects of telmisartan in patients with hypertension.

AIMS Left ventricular (LV) torsion may be an important component of normal LV systolic function. However, its mechanics remain unresolved. Two-dimensional (2-D) strain imaging is increasingly used to quantify LV torsion in the clinical setting. Telmisartan has cardioreparative effects, including attenuation of subendocardial myocardial fibrosis and improvement of LV remodelling. To clarify the mechanisms of LV torsion, in the present study, we evaluated changes in LV longitudinal deformation and torsion after medication with telmisartan using 2-D strain imaging in patients with hypertension (HT). METHODS AND RESULTS Telmisartan (20-40 mg daily) was administered to 37 previously untreated patients with HT. Two-dimensional strain echocardiography was performed after medication had been continued for 1-2 months with normal values for blood pressure (BP) (phase I) and for 12 months (phase II). In the phase II, relative LV wall thickness, LV mass index, LV torsion, and torsional rate were reduced, whereas the mean peak systolic longitudinal strain and strain rate were increased, compared to the phase I. LV torsion correlated well with relative LV wall thickness, but not LV mass index. CONCLUSION Our results obtained from cardioreparative effects of telmisartan suggested that LV torsion is associated with systolic longitudinal deformation related to subendocardial myocardial fibrosis, and/or LV concentric hypertrophy-related difference in torques between the subendocardial and subepicardial sides.

Association of left atrial reservoir function with left atrial structural remodeling related to left ventricular dysfunction in asymptomatic patients with hypertension: evaluation by two-dimensional speckle-tracking echocardiography

Abstract Left atrial (LA) structural and functional abnormalities are vital steps on the pathway toward heart failure with preserved ejection fraction in asymptomatic patients. The purpose of this study was to assess the relationship of LA function, particularly reservoir function, with LA structural remodeling related to the left ventricular (LV) dysfunction in asymptomatic patients with hypertension (HT) using conventional, tissue Doppler, and 2-D speckle-tracking echocardiography. Fifty age-matched healthy individuals and 140 patients with HT, including 75 with LA volume index (LAVI) < 29 ml/m2 (normal LA group) and 65 with LAVI ≥ 29 ml/m2 (large LA group), were enrolled. We defined peak early diastolic transmitral flow velocity/peak early diastolic mitral annular motion velocity (E/e′)/peak systolic LA strain (S-LAs) as LA diastolic stiffness. The LV mass index, relative LV wall thickness, peak atrial systolic transmitral flow velocity, LA total, active, and passive emptying volume indexes, and E/e′/S-LAs were greatest, and S-LAs, peak early diastolic LA strain, peak systolic LV longitudinal strain and circumferential strain rate, and peak early diastolic LV radial strain rate were lower in the large LA group compared with control and/or normal LA group. Multivariate linear regression analysis revealed that aging, LA remodeling, and LV systolic and diastolic dysfunction are defined as strong predictors related to increased LA diastolic stiffness in the large LA group. HT alters LA dynamics significantly, with resultant increased LA volume and diastolic stiffness related to LV diastolic and systolic dysfunction, even in asymptomatic patients. Earlier treatment with reninangiotensin system inhibitors may improve abnormal LA-LV interaction in this patient population.

Telmisartan improves morphologic and functional changes in both left ventricular myocardium and carotid arterial wall in patients with hypertension: assessment by tissue Doppler imaging and carotid ultrasonography.

Objective: The aim of the present study was to clarify the beneficial effects of telmisartan on the morphologic and functional changes in left ventricular (LV) myocardium and carotid arterial wall in patients with hypertension (HT) using tissue Doppler imaging and carotid ultrasonography. Methods: Telmisartan (20–40 mg daily) was administered to 35 previously untreated patients with HT. Conventional and pulsed tissue Doppler echocardiography were performed after medication had been continued for 1–2 months with normal values for blood pressure (BP) (phase I) and for 12 months (phase II). Subclinical atherosclerosis also was determined by measuring the intima‐media thickness (IMT) and stiffness β of the left and right common carotid arteries using B‐ and M‐mode ultrasonography. Results: In the phase II, the LV mass index and isovolumic relaxation time were lower, the peak systolic and early diastolic mitral annular motion velocities were greater compared to the phase I. The stiffness β and mean IMT were lower in the phase II than in the phase I. On multivariate regression analyses, age, BP, and LV diastolic variables emerged as stronger predictors of carotid arterial IMT and stiffness β. Conclusions: The 1‐year use of telmisartan improved LV hypertrophy, regional LV myocardial contraction and relaxation, and carotid atherosclerosis in patients with HT. Our results support cardio‐ and arterioprotective benefits from continuous long‐term telmisartan monotherapy, and combined analysis of tissue Doppler imaging and carotid ultrasonography may be a useful tool for understanding ventriculoarterial coupling in patients with HT. (Echocardiography 2010;27:864‐872)

Clinical Significance of the Reversed Mitral Annular Motion Velocity Wave at the Beginning of the Mitral Valve Closure

Background: Pulsed tissue Doppler imaging is increasingly used to record mitral annular motion (MAM) velocity pattern. A reversed MAM velocity wave (Cm) is commonly seen at the beginning of the mitral valve closure in timing, whereas the underlying mechanism and clinical significance have not been studied. Methods: Conventional, pulsed Doppler, pulsed tissue Doppler, and two‐dimensional strain echocardiography were performed in 100 consecutive patients with cardiovascular risk factors. Results: There were no correlations between the peak Cm and the ratio of peak early diastolic transmitral flow velocity to peak early diastolic MAM velocity (E/Em) and Tei index. The peak Cm correlated with left ventricular (LV) ejection fraction, left atrial volume index (LAVI) and left atrial ejection fraction, isovolumic relaxation time, peak LV systolic strains and strain rates during atrial systole in the longitudinal and circumferential directions, and peak LV systolic strain rates in the longitudinal, circumferential, and radial directions. Multivariate linear regression analysis revealed that LAVI is a independent predictor related to peak Cm. Conclusion: The Cm is regulated by mitral annular motion velocity toward the LA due to closing of the mitral valve, and may be used as a predictive tool for determining the “disease history” of chronic LV diastolic dysfunction in patients with no marked elevation in the LV filling pressure. (Echocardiography 2010;27:784‐790)