Background: Cardiac resynchronization therapy (CRT) has been shown to improve heart failure (HF) symptoms in adults. However, data showing improvement in various echocardiographic (ECHO) parameters following CRT is lacking in the younger population. We sought to evaluate ECHO markers of response in children and young adults undergoing CRT. Methods: This retrospective review included patients who underwent CRT at our institution. Patients with single ventricle physiology or poor images were excluded. CRT efficacy during placement was determined by ≥ 15% increase in directly measured dP/dt. ECHOs (prior, 1 month post and 12 months post CRT) were read by a single reader blinded to clinical data. Left ventricular (LV) longitudinal strain (LS) and left atrial strain (LAS) were measured offline using Tomtec software. LV endocardial, myocardial and average peak and end systolic strain were obtained. LAS was reported independently for the reservoir (LASr), conduit (LAScd) and booster phase (LASct). LV sphericity index was calculated as the ratio of the long-axis by short-axis length (SIs and SId). LV ejection fraction (EF) was calculated using the 5/6 area length method. Statistical analysis was performed using SPSS software and p of < 0.05 was considered significant Results: Of the 16 patients evaluated, 9(56.3%) were female. Mean age at CRT initiation was 18.3 ± 5.8 years. Primary diagnoses included dilated cardiomyopathy (12.5%), congenital complete atrioventricular block (37.5%), myocarditis (12.5%), and congenital heart disease (37.5%). Mean baseline dP/dt was 561mmHg-sec which improved to 830 (by 51%, p < 0.05) immediately after CRT with clinical NYHA class improvement at 12 month follow up visit. LV EF improved from 22.8 % to 28 % one year after CRT. The mean average peak LV strain (-6.6 ± 2.8 to -9.2 ± 4.8), as well as LAS during reservoir (21.7 ± 10.6 to 28.6 ± 11.5), conduit (-15.9 ± 7.8 to -19.2 ± 8.9) and booster (-5.8 ± 4 to -9.3 ± 4.3) phases improved at the 12 month follow-up visit. Despite showing improvement, none of the parameters exhibited the power to reach statistical significance (p > 0.05) Conclusion: This first study of multiple ECHO parameters to evaluate CRT efficacy in children and young adult patients failed to establish one parameter as superior to others. Although various parameters showed improvement, none reached levels of statistical significance. This could be related to our relatively small sample size and follow up duration or it is possible that the response to CRT in these patients requires more invasive and directly measured hemodynamic parameters such as ventricular contractility. Studies with larger cohorts may be helpful in further evaluating the efficacy of non-invasive parameters in predicting response to CRT in this population

Changes in ECHO parameters after CRT implantation

Changes in ECHO parameters after CRT implantation

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