P2A159: Exploration of Global Longitudinal and Circumferential Strain Patterns in Pediatric Patients with Essential Hypertension

Background: Hypertensive cardiomyopathy is a cardiac maladaptation to systemic hypertension which has been shown to be more pronounced in African American (AA) adults. Strain echocardiography can detect subclinical myocardial dysfunction due to hypertensive cardiomyopathy prior to the onset of clinical disease. We compared strain patterns in pediatric self-identified AA and Caucasian (C) patients with essential hypertension. In addition, we compared strain patterns in patients with and without left ventricular hypertrophy.

Methods: This was a single center, retrospective analysis of AA and C patients ≤18 years old (n=57) with essential hypertension. Patients with secondary hypertension due to renal disease or endocrine disease were excluded. The first echocardiogram at the time of diagnosis of essential hypertension was analyzed. Using vendor independent software (TomTec Imaging, Inc.), a single observer blinded to clinical data measured endocardial and myocardial global longitudinal strain (GLSendo and GLSmyo) in end systole in the apical four chamber view. Endocardial and myocardial global circumferential strain (GCSendo and GCSmyo) were also measured in end systole on the parasternal short axis view at papillary muscle level. Left ventricular mass (LVM) was measured using standard M mode and significant left ventricle hypertrophy (LVH) was defined as LVMindex >51 g/m2.7, regardless of race. GLSendo to GCSendo ratio was calculated to assess the adaptation of LV. Student t-test (SPSS Inc.) was used for comparisons and p< 0.05 was considered significant.

Results: Our cohort consisted of 57 patients with mean (SD) age of 14.8 (3.4) years, 38 (66.7%) were male and 40 (70%) were AA. There were no differences in height, weight, body surface area, body mass index, or LVMindex (AA 36.4 ± 12.6 vs C 31.5 ± 6.3 g/m2.7, p = 0.141) between AA and C groups. There were no statistically significant differences in GLSendo, GLSmyo, GCSendo, and GCSmyo in end-systole nor in the ratio of longitudinal to circumferential strain between the two AA and C groups. Seven (12.3%) patients had evidence of significant LVH, as defined (LVMi >51 g/m2.7 ). There were no statistically significant differences in anthropometric data or strain patterns between patients with and without LVH.

Conclusion: There was no statistically significant differences in strain patterns between pediatric self-identified African American and Caucasian patients with essential hypertension. Moreover, there was no consistent correlation between strain patterns and presence of left ventricular hypertrophy in this cohort, regardless of race. The younger age and timing of the echocardiogram at initial diagnosis may explain our findings, which are different than in adults. A longitudinal study is warranted to assess LV strain in pediatric patients with essential hypertension.