Assessment of left-ventricular mass and remodeling in obese adolescents

A new method to quantify left ventricular mass by 2D echocardiography

Increased left ventricular mass (LVM) is a strong independent predictor for adverse cardiovascular events, but conventional echocardiographic methods are limited by poor reproducibility and accuracy. We developed a novel method based on adding the mean wall thickness from the parasternal short axis view, to the left ventricular end-diastolic volume acquired using the biplane model of discs. The participants (n = 85) had various left ventricular geometries and were assessed using echocardiography followed immediately by cardiac magnetic resonance, as reference. We compared our novel two-dimensional (2D) method to various conventional one-dimensional (1D) and other 2D methods as well as the three-dimensional (3D) method. Our novel method had better reproducibility in intra-examiner [coefficients of variation (CV) 9% vs. 11–14%] and inter-examiner analysis (CV 9% vs. 10–20%). Accuracy was similar to the 3D method (mean difference ± 95% limits of agreement, CV): Novel: 2 ± 50 g, 15% vs. 3D: 2 ± 51 g, 16%; and better than the “linear” 1D method by Devereux (7 ± 76 g, 23%). Our novel method is simple, has considerable better reproducibility and accuracy than conventional “linear” 1D methods, and similar accuracy as the 3D-method. As the biplane model forms part of the standard echocardiographic protocol, it does not require specific training and provides a supplement to the modern echocardiographic report.

Association of Blood Pressure Level With Left Ventricular Mass in Adolescents

Hypertension is associated with left ventricular hypertrophy (LVH), a risk factor for cardiovascular events. Since cardiovascular events in youth are rare, hypertension has historically been defined by the 95th percentile of the normal blood pressure (BP) distribution in healthy children. The optimal BP percentile associated with LVH in youth is unknown. We aimed to determine the association of systolic BP (SBP) percentile, independent of obesity, on left ventricular mass index (LVMI), and to estimate which SBP percentile best predicts LVH in youth. We evaluated SBP, anthropometrics, and echocardiogram in 303 adolescents (mean age 15.6 years, 63% white, 55% male) classified by SBP as low-risk (L=141, <80th percentile), mid-risk (M=71, 80-<90th percentile), or high-risk (H=91, ≥90th percentile) using the mean of 6 measurements at 2 visits according to the 2017 guidelines. Logistic regression was used to determine the sensitivity and specificity of various SBP percentiles associated with LVH. Results: BP groups did not differ by age or demographics but differed slightly by body mass index. Mean BP, LVMI, and prevalence of LVH increased across groups (BP: L=111/75, M=125/82, and H=133/92 mm Hg; LVMI: L=31.2, M=34.2, and H=34.9 g/m^2.7; LVH: L=13%, M=21%, H=27%, all P<0.03). SBP percentile remained a significant determinant of LVMI after adjusting for covariates. The 90th percentile for SBP resulted in the best balance between sensitivity and specificity for predicting LVH (LVMI≥38.6 g/m^2.7). Abnormalities in cardiac structure in youth can be found at BP levels below those used to define hypertension.

Cardiac Imaging in Heart Failure with Comorbidities

Imaging modalities stand at the frontiers for progress in congestive heart failure (CHF) screening, risk stratification and monitoring. Advancements in echocardiography (ECHO) and Magnetic Resonance Imaging (MRI) have allowed for improved tissue characterizations, cardiac motion analysis, and cardiac performance analysis under stress. Common cardiac comorbidities such as hypertension, metabolic syndromes and chronic renal failure contribute to cardiac remodeling, sharing similar pathophysiological mechanisms starting with interstitial changes, structural changes and finally clinical CHF. These imaging techniques can potentially detect changes earlier. Such information could have clinical benefits for screening, planning preventive therapies and risk stratifying patients. Imaging reports have often focused on traditional measures without factoring these novel parameters. This review is aimed at providing a synopsis on how we can use this information to assess and monitor improvements for CHF with comorbidities.

Left ventricular mass and systolic function in children with chronic kidney disease-comparing echocardiography with cardiac magnetic resonance imaging

BACKGROUND

Increased left ventricular mass (LVM) is an important risk marker of uremic cardiovascular disease. Calculation of LVM by echocardiography (Echo) relies on geometric assumptions and in adults on hemodialysis overestimates LVM compared to cardiac magnetic resonance (CMR). We compare both techniques in children with chronic kidney disease (CKD).

METHODS

Concurrent Echo and CMR was performed in 25 children with CKD (14 after kidney transplantation) aged 8-17 years.

RESULTS

Compared to normal children, CMR-LVM was increased (standard deviation score (SDS) 0.39 ± 0.8 (p = 0.03)), stroke volume and cardiac output decreased (SDS -1.76 ± 1.1, p = 0.002 and -1.11 ± 2.0, p = 0.001). CMR-LVM index but not Echo-LVMI correlated to future glomerular filtration rate (GFR) decline (r = -0.52, p = 0.01). Mean Echo-LVM was higher than CMR-LVM (117 ± 40 vs. 89 ± 29 g, p < 0.0001), with wide limits of agreement (-6.2 to 62.8 g). The Echo-CMR LVM difference increased with higher Echo-LVMI (r = 0.77, p < 0.0001). Agreement of classifying left ventricular hypertrophy was poor with Cohen's kappa of 0.08. Mean Echo and CMR-ejection fraction differed by 1.42% with wide limits of agreement (-12.6 to 15.4%).

CONCLUSIONS

Echo overestimates LVM compared to CMR, especially at higher LVM. Despite this, CMR confirms increased LVM in children with CKD. Only CMR-LVMI but not Echo-LVMI correlated to future GFR decline.

The role of echocardiography in the evaluation of cardiac damage in hypertensive obese patient

Obesity rates are rising worldwide. Often obesity is associated with hypertension leading to an increased cardiovascular risk. Both obesity and hypertension induce several modifications in cardiac structure and function, particularly atrial and ventricular remodeling is a common finding shared by these two conditions. It has been demonstrated obesity leads to: left ventricular (LV) mass increase, LV systolic and diastolic dysfunction, left atrium (LA) size increase, LA function alterations and pericardial fat accumulation. Nowadays, the development of cardiac imaging techniques allows to early identifying any preclinical damage related to hypertension and obesity. This could be very important in order to improve patient management and medical therapy.

Early changes of left ventricular geometry and deformational analysis in obese subjects without cardiovascular risk factors: a three-dimensional and speckle tracking echocardiographic study

Subclinical myocardial dysfunction has been identified in obese subjects without cardiovascular risks factors and has been defined as "obesity cardiomyopathy". We evaluated left ventricular (LV) function and geometry in obese patients by using a 3 dimensional echocardiography (3DE). We also aimed to look at the influence of ventricular geometry upon functional parameters of the LV by using 3D speckle tracking imaging (3D-STI). 30 consecutive and asymptomatic obese cases (OB group) with no comorbidities were prospectively enrolled. The control group included 30 healthy volunteers (HS group), matched for age and sex. All subjects underwent 3DE and 3D-STI. Ventricular geometry was evaluated with the LV sphericity index (LV SpI) and the LV diastolic volume to mass ratio (LV EDV/Mass ratio). LV Mass was significantly increased in OB group and the LV EDV/Mass ratio had a significantly lower mean value in this group (p < 0.001 and p = 0.002, respectively). LV SpI was significantly reduced in obese subjects (p < 0.001). A significant reduction in longitudinal (GLS), radial (GRS) and area strain (GAS) was observed in OB group (p = 0.001 for all) while circumferential mechanic (GCS) was not different between the two groups (p = 0.052). LV EDV to mass ratio was significantly related to GLS (r = -0.298, p = 0.022) and GAS (r = -0.289, p = 0.026). On multivariate analysis, GRS and GAS were independently related to LV SpI (β = 0.222, p = 0.031 and β = -0.222, p = 0.034, respectively). Geometrical and structural ventricular remodeling negatively influences functional properties of the LV in obese subjects without cardiovascular risks factors. Further studies are needed to assess the prognostic value of our findings.

Concordance of measures of left-ventricular hypertrophy in pediatric hypertension

The American Academy of Pediatrics (AAP) recommends that any child diagnosed with hypertension have an echocardiogram to evaluate for the presence of left-ventricular (LV) hypertrophy (LVH) and advocates that LVH is an indication to initiate or intensify antihypertensive therapy. However, there is no consensus on the ideal method of defining LVH in the pediatric population. Many pediatric cardiologists rely on wall-thickness z-score of the LV posterior wall and/or interventricular septum to determine LVH. Yet, the AAP advocates using LV mass indexed to 2.7 (LVMI(2.7)) ≥ 51 g/m(2.7) to diagnose LVH. Recently, age-specific reference values for LVMI ≥ 95% were developed. The objective of the study was to determine the concordance between diagnosis of LVH by wall-thickness z-score and diagnosis by LVMI(2.7) criteria. A retrospective chart review was performed for subjects diagnosed with hypertension at a single tertiary care center (2009-2012). Echocardiogram reports were reviewed, and assessment of LVH was recorded. Diagnosis of LVH was assigned to each report reviewed according to three criteria: (1) LV wall-thickness z-score > 2.00; (2) age-specific reference values for LVMI(2.7) > 95th percentile; and (3) LVMI(2.7) > 51 g/m(2.7). Cohen's kappa statistic was used as a measurement of agreement between diagnosis by wall-thickness z-score and diagnosis using LVMI(2.7). A total of 159 echocardiograms in 109 subjects were reviewed. Subjects included 31 females and 77 males, age 13.2 ± 4.4 years, and 39 (42%) with a diagnosis of secondary hypertension. LVH was diagnosed in 31 cases (20%) based on increased wall-thickness z-score. Using LVMI(2.7) > 95%, LVH was found in 75 (47%) cases (mean LVMI(2.7)42.3 ± 17.2 g/m(2.7) [range 11.0-111 g/m(2.7)]). The wall-thickness z-score method agreed with LVMI(2.7) > 95% diagnosis 71% of the time (kappa 0.4). Using LVH criteria of LVMI(2.7) ≥ 51 g/m(2.7), 33 (21%) subjects were diagnosed with LVH. There was 79% agreement in the diagnosis of LVH between the wall-thickness z-score method and LVMI(2.7) > 51 g/m(2.7) (kappa 0.37). There is poor concordance between the diagnosis of LVH on echocardiogram reports using wall-thickness z-score and diagnosis of LVH using LVMI(2.7) criteria. It is important to establish a consensus method for diagnosing LVH because of the high frequency of cardiovascular complications in children with hypertension.

The clinical benefits of adding a third dimension to assess the left ventricle with echocardiography

Three-dimensional echocardiography is a novel imaging technique based on acquisition and display of volumetric data sets in the beating heart. This permits a comprehensive evaluation of left ventricular (LV) anatomy and function from a single acquisition and expands the diagnostic possibilities of noninvasive cardiology. It provides the possibility of quantitating geometry and function of LV without preestablished assumptions regarding cardiac chamber shape and allows an echocardiographic assessment of the LV that is less operator-dependent and therefore more reproducible. Further developments and improvements for widespread routine applications include higher spatial and temporal resolution to improve image quality, faster acquisition, processing and reconstruction, and fully automated quantitative analysis. At present, three-dimensional echocardiography complements routine 2DE in clinical practice, overcoming some of its limitations and offering additional valuable information that has led to recommending its use for routine assessment of the LV of patients in whom information about LV size and function is critical for their clinical management.