Myocardial Strain Characterization in Different Left Ventricular Adaptative Responses to High Blood Pressure: A Study Based on 3D-Wall Motion Tracking Analysis

Advanced imaging tools for evaluating cardiac morphological and functional impairment in hypertensive disease

Arterial hypertension represents a systemic burden, and it is responsible of various morphological, functional and tissue modifications affecting the heart and the cardiovascular system. Advanced imaging techniques, such as speckle tracking and three-dimensional echocardiography, cardiac magnetic resonance, computed tomography and PET-computed tomography, are able to identify cardiovascular injury at different stages of arterial hypertension, from subclinical alterations and overt organ damage to possible complications related to pressure overload, thus giving a precious contribution for guiding timely and appropriate management and therapy, in order to improve diagnostic accuracy and prevent disease progression. The present review focuses on the peculiarity of different advanced imaging tools to provide information about different and multiple morphological and functional aspects involved in hypertensive cardiovascular injury. This evaluation emphasizes the usefulness of the emerging multiimaging approach for a comprehensive overview of arterial hypertension induced cardiovascular damage.

Morphological and functional cardiac consequences of rapid hypertension treatment: a cohort study

BACKGROUND

Left ventricular (LV) hypertrophy (LVH) in uncontrolled hypertension is an independent predictor of mortality, though its regression with treatment improves outcomes. Retrospective data suggest that early control of hypertension provides a prognostic advantage and this strategy is included in the 2018 European guidelines, which recommend treating grade II/III hypertension to target blood pressure (BP) within 3 months. The earliest LVH regression to date was demonstrated by echocardiography at 24 weeks. The effect of a rapid guideline-based treatment protocol on LV remodelling, with very early BP control by 18 weeks remains controversial and previously unreported. We aimed to determine whether such rapid hypertension treatment is associated with improvements in LV structure and function through paired cardiovascular magnetic resonance (CMR) scanning at baseline and 18 weeks, utilising CMR mass and feature tracking analysis.

METHODS

We recruited participants with never-treated grade II/III hypertension, initiating a guideline-based treatment protocol which aimed to achieve BP control within 18 weeks. CMR and feature tracking were used to assess myocardial morphology and function immediately before and after treatment.

RESULTS

We acquired complete pre- and 18-week post-treatment data for 41 participants. During the interval, LV mass index reduced significantly (43.5 ± 9.8 to 37.6 ± 8.3 g/m2, p < 0.001) following treatment, accompanied by reductions in LV ejection fraction (65.6 ± 6.8 to 63.4 ± 7.1%, p = 0.03), global radial strain (46.1 ± 9.7 to 39.1 ± 10.9, p < 0.001), mid-circumferential strain (- 20.8 ± 4.9 to - 19.1 ± 3.7, p = 0.02), apical circumferential strain (- 26.0 ± 5.3 to - 23.4 ± 4.2, p = 0.003) and apical rotation (9.8 ± 5.0 to 7.5 ± 4.5, p = 0.003).

CONCLUSIONS

LVH regresses following just 18 weeks of intensive antihypertensive treatment in subjects with newly-diagnosed grade II/III hypertension. This is accompanied by potentially advantageous functional changes within the myocardium and supports the hypothesis that rapid treatment of hypertension could improve clinical outcomes.

TRIAL REGISTRATION

ISRCTN registry number: 57475376 (assigned 25/06/2015).

Evaluation of Left Ventricular Systolic Function and Mass in Primary Hypertensive Patients by Echocardiography

Hypertension is an independent risk factor for cardiovascular diseases. The accurate evaluation of cardiovascular risk is of paramount importance in the management of hypertensive patients. Conventional echocardiographic methods have provided the assessment of left ventricular systolic function and mass for many years. Tissue Doppler imaging, 3-dimensional echocardiography, and speckle tracking echocardiography are newer echocardiographic modalities for the left ventricular systolic function and mass quantification. The major emphasis of this review is to evaluate the left ventricular systolic function and mass by conventional and newly developed echocardiographic in hypertensive patients.

Vortical features for myocardial rotation assessment in hypertrophic cardiomyopathy using cardiac tagged magnetic resonance

Left ventricular rotational motion is a feature of normal and diseased cardiac function. However, classical torsion and twist measures rely on the definition of a rotational axis which may not exist. This paper reviews global and local rotation descriptors of myocardial motion and introduces new curl-based (vortical) features built from tensorial magnitudes, intended to provide better comprehension about fibrotic tissue characteristics mechanical properties. Fifty-six cardiomyopathy patients and twenty-two healthy volunteers have been studied using tagged magnetic resonance by means of harmonic phase analysis. Rotation descriptors are built, with no assumption about a regular geometrical model, from different approaches. The extracted vortical features have been tested by means of a sequential cardiomyopathy classification procedure; they have proven useful for the regional characterization of the left ventricular function by showing great separability not only between pathologic and healthy patients but also, and specifically, between heterogeneous phenotypes within cardiomyopathies.

Myocardial Deformation Measured by 3-Dimensional Speckle Tracking in Children and Adolescents With Systemic Arterial Hypertension

Systemic arterial hypertension predisposes children to cardiovascular risk in childhood and adult life. Despite extensive study of left ventricular (LV) hypertrophy, detailed 3-dimensional strain analysis of cardiac function in hypertensive children has not been reported. The aim of this study was to evaluate LV mechanics (strain, twist, and torsion) in young patients with hypertension compared with a healthy control group and assess factors associated with functional measurements. Sixty-three patients (26 hypertension and 37 normotensive) were enrolled (mean age, 14.3 and 11.4 years; 54% men and 41% men, respectively). All children underwent clinical evaluation and echocardiographic examination, including 3-dimensional strain. There was no difference in LV volumes and ejection fraction between the groups. Myocardial deformation was significantly reduced in those with hypertension compared with controls. For hypertensive and normotensive groups, respectively, global longitudinal strain was -15.1±2.3 versus -18.5±1.9 (P<0.0001), global circumferential strain -15.2±3 versus -19.9±3.1 (<0.0001), global radial strain +44.0±11.3 versus 63.4±10.5 (P<0.0001), and global 3-dimensional strain -26.1±3.8 versus -31.5±3.8 (P<0.0001). Basal clockwise rotation, apical counterclockwise rotation, twist, and torsion were not significantly different. After multivariate regression analyses blood pressure, body mass index and LV mass maintained a significant relationship with measures of LV strain. Similar ventricular volumes and ejection fraction were observed in hypertensive and normotensive children, but children with hypertension had significantly lower strain indices. Whether reduced strain might predict future cardiovascular risk merits further longitudinal study.

The relationship between left ventricular deformation and different geometric patterns according to the updated classification: findings from the hypertensive population

OBJECTIVE

We sought to investigate left ventricular mechanics in hypertensive patients with different geometric patterns by using two-dimensional (2DE) and three-dimensional (3DE) strain analysis.

METHODS

This cross-sectional study included 197 hypertensive individuals who underwent a complete 2DE and 3DE examination. We applied the new updated criteria of left ventricular geometry that considered left ventricular mass index, left ventricular end-diastolic diameter and relative wall thickness. According to this classification the individuals were divided into six groups: normal geometry, concentric remodelling, eccentric nondilated left ventricular hypertrophy (LVH), concentric LVH, dilated LVH and concentric-dilated LVH.

RESULTS

Multidirectional 2DE and 3DE left ventricular strain decreased from the hypertensive patients with normal geometry, across the individuals with left ventricular concentric remodelling, eccentric nondilated LVH, to the patients with concentric LVH and dilated LVH patterns. The reduction of left ventricular systolic and early diastolic strain rates was noticed to be heading in the same direction, as well as the elevation of late diastolic strain rates. Left ventricular twist and torsion were increased in the participants with concentric and dilated LVH patterns. Reduced 2DE and 3DE strains were associated with concentric and dilated LVH patterns independent of demographic and clinical parameters.

CONCLUSION

Left ventricular deformation in hypertensive patients is significantly impacted by left ventricular geometry. Concentric and dilated LVH patterns have the greatest unfavourable effect on 2DE and 3DE left ventricular mechanics. The updated classification of left ventricular geometry provides valuable and comprehensive information about left ventricular mechanical deformation and function in hypertensive population.

Wave Intensity Analysis Can Identify Eccentric Cardiac Hypertrophy in Hypertensive Patients With Varied Left Ventricular Configurations

OBJECTIVES

The primary aim of this study was to determine whether wave intensity can discriminate cases of eccentric hypertrophy in patients with essential hypertension who have varied left ventricular configurations.

METHODS

A total of 155 hypertensive patients with different ventricular configurations (27 normal configuration, 42 concentric remodeling, 62 concentric hypertrophy, and 24 eccentric hypertrophy) were recruited. We performed a noninvasive wave intensity analysis of the common carotid artery and conventional echocardiography. Blood pressure and flow velocity were measured in the right carotid artery of all patients.

RESULTS

The left ventricular ejection fraction (LVEF) in the eccentric hypertrophy group was significantly lower than the values in the other groups (P < .05). The R-W1 interval/W1-W2 interval ratio (where W1 indicates the first positive peak and W2 the second positive peak) in the eccentric hypertrophy group was much higher than the values in the other groups (P < .05). However, there were no significant differences in W1, W2, and negative area among these groups. Pearson correlation analysis showed that R-W1/W1-W2, R-W1, and W1-W2were correlated with the LVEF, whereas there was no correlation between W1, W2, negative area, and the reflection coefficient with the LVEF.

CONCLUSIONS

We propose that by using the R-W1/W1-W2 ratio, wave intensity analysis can identify hypertensive patients with eccentric hypertrophy without the need for echocardiography.

Association between left ventricular mechanics and heart rate variability in untreated hypertensive patients

The authors sought to investigate left ventricular (LV) mechanics and heart rate variability (HRV), and their relationship, in untreated hypertensive patients. A total of 63 untreated hypertensive patients and 45 healthy patients were included. All patients underwent 24-hour Holter monitoring and echocardiographic examination (two- and three-dimensional). All parameters of time and frequency domain of HRV were decreased in the hypertensive patients. Two-dimensional LV longitudinal and circumferential deformation was significantly reduced in hypertensive patients. Three-dimensional LV strain in all three directions as well as area strain were reduced in the hypertensive group. In two different models of multivariate regression, two-dimensional LV longitudinal and circumferential strain, as well as three-dimensional LV area strain, remained associated with HRV parameters independently of LV structural and functional parameters. This study showed that LV mechanics and HRV were significantly impaired in untreated hypertensive patients. Two- and three-dimensional echocardiographic LV deformation were independently associated with HRV parameters in the whole study population.

Evaluation of left ventricular torsion in children with hypertrophic cardiomyopathy

AIMS

To evaluate the role of torsion in hypertrophic cardiomyopathy in children.

METHODS

A total of 88 children with idiopathic hypertrophic cardiomyopathy (n = 24) and concentric hypertrophy (n = 20) were investigated with speckle-tracking echocardiography and compared with age- and gender-matched healthy controls (n = 44).

RESULTS

In hypertrophic cardiomyopathy, we found increased torsion (2.8 ± 1.6 versus 1.9 ± 1.0°/cm [controls], p < 0.05) because of an increase in clockwise basal rotation (-8.7 ± 4.3° versus -4.9 ± 2.5° [controls], p < 0.001) and prolonged time to peak diastolic untwisting (3.7 ± 2.4% versus 1.7 ± 0.6% [controls] of cardiac cycle, p < 0.01), but no differences in peak untwisting velocities. Hypertrophic cardiomyopathy patients demonstrated a negative correlation between left ventricular muscle mass and torsion (r = -0.7, p < 0.001). In concentric hypertrophy, torsion was elevated because of increased apical rotation (15.1 ± 6.4° versus 10.5 ± 5.5° [controls], p < 0.05) without correlation with muscle mass. Peak untwisting velocities (- 202 ± 88 versus -145 ± 67°/s [controls], p < 0.05) were higher in concentric hypertrophy and time to peak diastolic untwisting was delayed (1.8 ± 0.8% versus 1.2 ± 0.6% [controls], p < 0.05).

CONCLUSIONS

In contrast to an increased counterclockwise apical rotation in concentric hypertrophy, hypertrophic cardiomyopathy is characterised by predominantly enhanced systolic basal clockwise rotation. Diastolic untwisting is delayed in both groups. Torsion may be an interesting marker to guide patients with hypertrophic cardiomyopathy.

Left ventricular twist and ventricular-arterial coupling in hypertensive patients

BACKGROUND

Left ventricular (LV) twist is usually influenced by LV hypertrophy resulting from hypertension or vascular stiffness. Vascular stiffness would increase arterial elastance (Ea), whereas LV end-systolic stiffness (Ees) could be influenced by LV hypertrophy. Therefore, in hypertensive patients, we assessed the extent to which ventricular-arterial coupling (VAC; Ea/Ees) affects LV twist, which may be a compensatory mechanism for systolic dysfunction.

METHODS

Hypertensive patients (n = 128) and healthy controls (n = 40) underwent conventional and speckle tracking echocardiography including LV twist. Ea and Ees were estimated noninvasively by echocardiography. Patients were divided into 3 tertiles according to the twist angle. Univariate and multivariate regression analyses were performed to test the influence of VAC on twist.

RESULTS

Patients in the lowest LV twist tertile had larger LV end-systolic volume, lower ejection fraction, lesser mid-wall fractional shortening (MWFS), and higher LV mass index (LVMI), compared to those with the highest tertile. They showed the lower septal tissue Doppler velocity, and global longitudinal and circumferential strain. With regard to VAC, Ea was similar among 3 groups, but Ees was significantly decreased in patient with lower tertile, resulting in increased VAC (1.1 ± 0.2 vs. 0.9 ± 0.1 vs. 0.7 ± 0.1, P < 0.001). While LV twist showed significant correlations with Ees, MWFS, and LVMI, VAC (β = -14.92, P < 0.001) was most associated with twist in a multivariate analysis.

CONCLUSIONS

LV twist was significantly associated with VAC in accordance with LV function; LV twist and VAC decreased progressively as LV systolic function deteriorated, while being enhanced during the well-compensated phase.

Two- and three-dimensional speckle tracking analysis of the relation between myocardial deformation and functional capacity in patients with systemic hypertension

The purpose of this study was to investigate left ventricular (LV) mechanics in hypertensive patients by 2- and 3-dimensional (3D) speckle tracking imaging, and determine the relation between the LV mechanics and functional capacity in this population. This cross-sectional study included 51 recently diagnosed, untreated, hypertensive patients, 49 treated subjects with well-controlled arterial hypertension, 52 treated participants with uncontrolled hypertension, and 50 controls adjusted by gender and age. All the subjects underwent 24-hour blood pressure monitoring, complete 2-dimensional and 3D examination, and cardiopulmonary exercise testing. 3D global longitudinal, circumferential, radial, and area strains were similar between the control group and well-controlled hypertensive patients but significantly decreased in comparison with patients with untreated or inadequately controlled hypertension. Similar findings were obtained for LV torsion and twist rate, whereas LV untwisting rate significantly deteriorated from the controls, across the well-controlled group, to the patients with untreated or uncontrolled hypertension. Peak oxygen uptake was significantly lower in the patients with untreated and uncontrolled hypertension than in the controls and the well-treated hypertensive patients. Peak oxygen uptake was independently associated with LV untwisting rate (β = 0.28, p = 0.03), 3D LV ejection fraction (β = 0.31, p = 0.024), and 3D global longitudinal strain (β = 0.26, p = 0.037) in the whole hypertensive population in our study. In conclusion, LV mechanics and functional capacity are significantly impaired in the patients with uncontrolled and untreated hypertension in comparison with the controls and the well-controlled hypertensive patients. Functional capacity is independently associated with 3D global longitudinal strain, LV untwisting rate, and 3D LV ejection fraction.

Eccentric may differ from concentric left ventricular hypertrophy because of variations in cardiomyocyte numbers

BACKGROUND

When overweight or hypertension is present, some patients at first examination exhibit left ventricular (LV) dilation and others concentric hypertrophy that persists indefinitely. Perhaps the ventricles with the fewest myocytes could enter systolic dysfunction with dilation and those with more myocytes may sustain persistent concentric hypertrophy.

METHODS AND RESULTS

Cardiomyocyte numbers, MyN, were counted in paraffin sections of left ventricles from 99 forensic autopsies, excluding instances of coronary heart disease. MyN lacked statistically significant relationships with age, race, sex, height, weight, LV mass, and mean arterial pressure estimated from renal histology. Specimens with the fewest myocytes, however, did manifest significant dilation and thinner chamber walls.

CONCLUSIONS

The tendency toward an eccentric pattern of hypertrophy in ventricles with the fewest myocytes is a clear conclusion, but has an ambiguous interpretation. This is the pattern expected from the initial hypothesis, but it also has other possible explanations. This ambiguity arises chiefly from limitations in the methods used for estimating MyN. These limitations are accessible to control in future studies. Our findings failed to contradict the hypothesis introduced here. These conclusions are implicit in the underlying observations of MyN constancy across such groupings as sex, height, weight, and LV mass, which provide the less speculative findings.

Alterations in ventricular structure and function in obese adolescents with nonalcoholic fatty liver disease

OBJECTIVE

To determine the association among nonalcoholic fatty liver disease (NAFLD), metabolic function, and cardiac function in obese adolescents.

STUDY DESIGN

Intrahepatic triglyceride (IHTG) content (magnetic resonance spectroscopy), insulin sensitivity and β-cell function (5-hour oral glucose tolerance test with mathematical modeling), and left ventricular function (speckle tracking echocardiography) were determined in 3 groups of age, sex, and Tanner matched adolescents: (1) lean (n=14, body mass index [BMI]=20±2 kg/m2); (2) obese with normal (2.5%) IHTG content (n=15, BMI=35±3 kg/m2); and (3) obese with increased (8.7%) IHTG content (n=15, BMI=37±6 kg/m2).

RESULTS

The disposition index (β-cell function) and insulin sensitivity index were ∼45% and ∼70% lower, respectively, and whole body insulin resistance, calculated by homeostasis model of assessment-insulin resistance (HOMA-IR), was ∼60% greater, in obese than in lean subjects, and ∼30% and ∼50% lower and ∼150% greater, respectively, in obese subjects with NAFLD than those without NAFLD (P<.05 for all). Left ventricular global longitudinal systolic strain and early diastolic strain rates were significantly decreased in obese than in lean subjects, and in obese subjects with NAFLD than those without NAFLD (P<.05 for all), and were independently associated with HOMA-IR (β=0.634). IHTG content was the only significant independent determinant of insulin sensitivity index (β=-0.770), disposition index (β=-0.651), and HOMA-IR (β=0.738).

CONCLUSIONS

These findings demonstrate that the presence of NAFLD in otherwise asymptomatic obese adolescents is an early marker of cardiac dysfunction.

The role of 3D wall motion tracking in heart failure

Heart failure is a major health problem in developed countries and a growing one in developing countries. Cardiac remodeling in heart failure affects myocardial mechanics, which requires comprehensive evaluation in three dimensions. The novel technique of 3D wall motion tracking applies speckle tracking technology to full volume, 3D echocardiographic datasets. Quantification of conventional and novel left ventricular (LV) parameters including volumes, ejection fraction, global and regional 3D strain, endocardial area strain, twist, and dyssynchrony, and identification of the site of latest mechanical activation are feasible on the basis of a single acquisition of a full-volume dataset. Clinical applications of 3D wall motion tracking include the assessment of global and regional LV performance in ischemic and nonischemic heart diseases, evaluation of mechanics in cardiomyopathies and congenital heart disease, potential selection of patients for cardiac resynchronization therapy and prediction of their response, and detection of subclinical cardiac dysfunction in diseases with likelihood of progression to heart failure. Technological advances with improvement in spatial and temporal resolution of this novel imaging modality are expected. Although 3D wall motion tracking is still in its infancy, this method has begun to provide new insights into LV mechanics and has already found clinical applications. Future developments in 3D assessment of right ventricular and myocardial layer-specific mechanics are awaited.

Preliminary clinical study of left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy by three-dimensional speckle tracking imaging

Background

Non-ischemic dilated cardiomyopathy (DCM) is the most common cardiomyopathy worldwide, with significant mortality. Correct evaluation of the patient's myocardial function has important clinical significance in the diagnosis, therapeutic effect assessment and prognosis in non-ischemic DCM patients. This study evaluated the feasibility of three-dimensional speckle tracking imaging (3D-STE) for assessment of the left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy (DCM).

Methods

Apical full-volume images were acquired from 65 patients with non-ischemic DCM (DCM group) and 59 age-matched normal controls (NC group), respectively. The following parameters were measured by 3D-STE: the peak systolic radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of each segment. Then all the parameters were compared between the two groups.

Results

The peak systolic strain in different planes had certain regularities in normal groups, radial strain (RS) was the largest in the mid region, the smallest in the apical region, while circumferential strain (CS) and longitudinal strain (LS) increased from the basal to the apical region. In contrast, the regularity could not be applied to the DCM group. RS, CS, LS were significantly decreased in DCM group as compared with NC group (P < 0.001 for all). The interobserver, intraobserver and test-retest reliability were acceptable.

Conclusions

3D-STE is a reliable tool for evaluation of left ventricular myocardial strain in patients with non-ischemic DCM, with huge advantage in clinical application.