Left ventricular myocardial deformation as measure of hemodynamic burden in congenital valvular aortic stenosis.

BACKGROUND: Changes in 2D echocardiography (2DE) speckle tracking imaging (STI) derived left ventricular (LV) strain (S) and strain rate (SR) precedes diminution of LV ejection fraction (LVEF) in adult valvular aortic stenosis (AS). We prospectively examined whether 2DE-STI derived multidirectional LV S and SR correlate with AS severity in children using LV mass index (MI) as the principal outcome variable. METHODS: 52 children (10.4 ± 7.3 years) with isolated congenital AS were included; 13 mild (2.5 m/s < Vmax < 3.0 m/s), 25 moderate (3.0 m/s < Vmax < 4.0 m/s), and 14 severe (Vmax > 4.0 m/s). 2DE including Doppler and STI longitudinal strain (LS), strain rate (LSR), circumferential strain (CS), and strain rate (CSR) were measured. Univariate and multivariable linear regressions identified correlations between LVMI and strain indices. RESULTS: Three clinical and 2DE variables, and four strain indices were independently associated with LVMI. LVMI correlated positively with systolic blood pressure and aortic regurgitation, and negatively with LVEF. LVMI correlated positively with LSR (four-chamber) and CSR (basal), and negatively with segmental CS in the inferior (basal) and anteroseptal (distal) segments. LVMI showed significant inverse association with LS (P = .05), LSR (P < .001), CS (P < .005), and CSR (P < .0001), independent of AS severity. CONCLUSIONS: Independent of clinical and 2DE findings including contemporaneous Doppler estimates of AS gradient, both longitudinal and circumferential strain indices correlate with LVMI as a measure of cumulative hemodynamic burden. This association implies subclinical LV dysfunction.

Is routine pre-operative cardiac evaluation necessary in obese children undergoing adenotonsillectomy for OSA?

BACKGROUND: Adenotonsillectomy (T&A) is a common surgery performed for obstructive sleep apnea (OSA) in children. Obese children are at increased risk for OSA, but are also at increased risk for cardiovascular changes that might heighten their risk of undergoing a general anesthetic. There is currently no standard of care recommendation for cardiac workup prior to T&A. PURPOSE: To ascertain whether a preoperative cardiac workup is predictive of postoperative complications in obese children undergoing T&A for OSA. DESIGN: Retrospective cohort review. MATERIAL AND METHODS: 241 children with BMI ≥ 25 kg/m(2) underwent T&A for OSA. This cohort was divided into three groups - those who had no preoperative cardiac evaluation, those who had a preoperative cardiac evaluation but no significant findings and those who had a preoperative cardiac evaluation with at least one significant finding. Postoperative cardiac-related complications were compared between the three groups. RESULTS: There were significantly more postoperative complications in Group 3, the group with findings on preoperative cardiac evaluation. However, these were heavily weighted toward "hospital stay > 24 hours" without clear cardiac sequelae. Notably there were no incidents of pulmonary edema, re-intubation postoperatively or death. CONCLUSION: In obese children undergoing T&A at a tertiary care center, a preoperative cardiac workup was not shown to be beneficial in predicting postoperative complications.

Abnormal Myocardial Strain Indices in Children Receiving Anthracycline Chemotherapy.

Anthracycline chemotherapy (AC) is associated with impaired left ventricular (LV) systolic function. LV ejection fraction (EF %) obtained by two-dimensional echocardiography is the current gold standard for detection and monitoring of LV systolic function. However, dependence on LVEF has been shown to be unreliable due to its inherent limitations. Speckle tracking echocardiography (STE) measures myocardial strain and is a sensitive method to detect LV systolic dysfunction with demonstrated utility in such detection in adult and pediatric cohort studies. Compare myocardial strain indices derived by STE with LVEF to detect ACT-induced LV systolic dysfunction. Prospective, cross-sectional measurements of LV myocardial strain indices derived from STE with LVEF. Pediatric cohort of 25 patients (pts): 17 females, eight males with a mean age 9.8 ± 5.8 years, who received anthracyclines (AC); median cumulative dose ≥150 ± 124.4 mg/m(2), range 60-450 mg/m(2) showing normal LV end-diastolic diameter (mm) and normal LVEF (≥55 %) underwent STE to obtain LV myocardial strain indices: strain and strain rate. The inter- and intraobserver variability for the strain indices was 5 %. Fifteen of 25 pts (60 %) showed abnormal global longitudinal peak systolic strain (GLPSS) and 19/25 pts (76 %) showed abnormal peak circumferential strain (PCS) compared to age-matched controls (p = 0.005). In contrast, no significant differences was observed in either indices with the dose of AC. Likewise, no significant changes in the systolic or diastolic strain rate were noted with the dose of AC (r (2) = 0.0076 for peak E, r (2) = 0.072 for peak A, p = NS). GLPSS and PCS were diminished and, however, correlated poorly with the cumulative dose of AC. These observations indicate an early onset of LV systolic dysfunction by the strain indices in pts who continue to show a normal LVEF implying presence of occult LV systolic dysfunction. These novel strain indices may assist in early detection of LV systolic dysfunction with implications for monitoring and prevention of AC-induced LV systolic dysfunction.