Electrocardiographic strain pattern in children with left ventricular hypertrophy: a marker of ventricular dysfunction

Cardiovascular screening in asymptomatic adolescents with metabolic syndrome

Background

In recent days, the prevalence of childhood metabolic syndrome (MS) has increased substantially due to the increasing rate of childhood obesity on a global scale. The aims of this study were to detect the important parameters and provide the screening system to prevent cardiovascular disease in adolescents with MS.

Methods

Ninety one male adolescents were divided into two groups based on the presence or absence of MS. Anthropometric measurement and laboratory study were studied. Intimal medial thickness and pulse wave velocity were estimated. Left ventricular mass index (LVMI), ejection fraction, myocardial velocity, strain and strain rate were measured by tissue Doppler imaging and strain rate imaging.

Results

The prevalence of MS was 7.7%. Weight, body mass index (BMI), waist circumference (WC), glucose, insulin, homeostasis model assessment of insulin resistance, triglyceride and LVMI were significantly increased in the MS group. High density lipoprotein-cholesterol (HDL-C), peak early diastolic myocardial velocity (e'), systolic myocardial velocity (s') and global longitudinal strain were significantly lower in the MS group. In univariant analysis, LVMI was significantly correlated with BMI, WC, fat %, fat mass, systolic blood pressure, alanine aminotransferase, total cholesterol (TC) and low density lipoprotein-cholesterol. e' was significantly correlated with BMI, fat %, fat mass, and HDL-C. Global circumferential strain had significant correlation with glucose and TC. Basal anterolateral strain rate was significantly correlated with weight, BMI, WC, fat %, and fat mass.

Conclusion

LVMI, strain and strain rate are practical and accurate parameters for assessment of left ventricular function in adolescents with MS.

The Electrocardiogram Is a Poor Diagnostic Tool to Detect Left Ventricular Hypertrophy in Children: A Comparison with Echocardiographic Assessment of Left Ventricular Mass

OBJECTIVE

The electrocardiogram (ECG) is used to detect left ventricular hypertrophy (LVH) in children and young adults, and it is considered an important screening tool for the most common causes of sudden cardiac arrest in the United States. However, the reliability and accuracy of the ECG in the detection of LVH are poorly understood. This study's objective was to assess the reliability and accuracy of ECG parameters predicting LVH in comparison with echocardiographic two-dimensional left ventricular mass (2D-LVM) assessment.

DESIGN

Two hundred fifty patients met study criteria with complete 2D-LVM measurements, temporally matched ECGs and no confounding structural heart defects. The echocardiographic diagnosis of LVH was made by 2D-LVM z-score > 2. The electrocardiographic diagnosis of LVH was fulfilled if specific Q, R, or S wave voltages exceeded the normal limits for the respective age groups established by the Davignon, Macfarlane and Rijnbeek datasets, or fulfilled the LVH criteria set forth by adult indices (Sokolow-Lyon, Cornell, Gubner, Romhilt-Estes).

RESULTS

None of the ECG parameters showed significant correlation with 2D-LVM z-scores. In the detection of LVH, the most commonly used R in V6 voltages showed the following results: sensitivity 13-29%, specificity 77-96%, positive predictive value (PPV) 29-50%, and negative predictive value (NPV) 77%. The overall accuracy ranged 65-75%. The accuracy of adult indices for LVH ranged from 49% to 78%.

CONCLUSIONS

The ECG's prediction of LVH is unreliable with dismal sensitivity, variable specificity, poor PPV, and barely acceptable NPV. With such overall poor reliability, the use of current ECG standards in screening for LVH warrants reassessment.

The asymptomatic teenager with an abnormal electrocardiogram

Use of medications for attention-deficit hyperkinetic disorder and preparticipation sports physical examination has led to an increase in number of electrocardiograms (ECG) performed during adolescence. Interpreting ECGs in children and young adults must take into account the evolutionary changes with age and the benign variants, which are usually not associated with heart disease. It is crucial for primary-care providers to recognize the changes on ECG associated with heart disease and risk of sudden death. In this article, the significance, sensitivity, specificity, and the diagnostic workup of these findings in the asymptomatic teenager are discussed.

Management of a hyperactive teen and cardiac safety

Since the earliest descriptions of the condition, controversy has prevailed as to the existence of as well as appropriate management of attention deficit hyperactivity disorder. Often diagnosed in childhood, symptoms of attention deficit hyperactivity disorder can continue into adolescence and adulthood, requiring lifelong therapy. Effective therapeutic interventions include stimulant medications with all their respective potential side effects, including the cardiovascular system. However, although initial studies raised concerns for an increase in serious adverse cardiovascular effects among children receiving these drugs, more recent and extensive reports have failed to substantiate those findings among young patients.

Early subclinical left-ventricular dysfunction in obese nonhypertensive children: a tissue Doppler imaging study

A direct effect of obesity on myocardial function has not been not well established. Our aim was to investigate the effect of body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA-IR) on left-ventricular (LV) myocardial function in normotensive overweight and obese children by tissue Doppler imaging (TDI). We calculated the mitral annular displacement index (DI) and myocardial performance index (MPI) using TDI indices of systolic and diastolic LV function. In this hospital-based, prospective cross-sectional study, we studied 60 obese (mean age 13.2 ± 2.0 years) and 50 normal children. Subjects were divided into three groups: group 1 (BMI < 25, n = 50, control), group 2 (BMI 25-29.9 kg/m(2), n = 30, overweight), and group 3 (BMI ≥ 30 kg/m(2), n = 30, morbidly obese). Standard echocardiography showed increased LV diameters and LV mass/index and preserved ejection fraction in obese children. By TDI, LV systolic and diastolic function showed that peak late myocardial velocity (Em = 15.4 ± 2 cm/s), peak early myocardial velocity (Am = 8.7 ± 1.3 cm/s), Em/Am ratio (1.8 ± 0.3), isovolumetric relaxation time (IVRT = 59.2 ± 8.2 ms), MPI (0.39 ± 0.03), and DI (25.5 ± 3.2 %) of the lateral mitral annulus in the obese subgroups were significantly different from those of control subjects (18.2 ± 1.2 cm/sn, 6.9 ± 0.6 cm/sn, 2.6 ± 0.2, 51.2 ± 9.6 ms, 0.34 ± 0.03, and 33.13 ± 5.0 %, respectively; p < 0.001). These structural and functional abnormalities were significantly related to BMI. There were positive correlations between HOMA-IR, septal MPI, and LV mass. DI and MPI data indicated impaired subclinical LV function in all grades of isolated obesity at a preclinical stage. Insulin resistance and BMI correlated significantly with indices of LV function.