Functional recovery of cardiomyopathy induced by atrial tachycardia in children: Insight from cardiac strain imaging

AIM: To evaluate systolic and diastolic cardiac function in children who had cardiomyopathy induced by ectopic atrial tachycardia (EAT). METHODS: Twenty-two pediatric patients who had cardiomyopathy induced by EAT and 25 age-matched controls were recruited in this case-control study. The patients were examined after rhythm control and normalization of their left ventricular systolic function. Different echocardiographic modalities including tissue Doppler imaging and two-dimension speckle tracking echocardiography were utilized to assess the ventricular and atrial function. RESULTS: The patients' median age was 51 months (interquartile range: 28.5-84 months). The median time interval required for normalization of left ventricular ejection fraction (EF) among patients was 1.5 months (interquartile range: 1.5-2.12 months). Compared to controls, patients had a significantly higher median left ventricular myocardial performance index (MPI) at the interventricular septum (0.44 vs. 0.38, p = .001) and left ventricular lateral wall (0.46 vs. 0.32, p = .0001). The median right ventricular MPI of the patients' group was significantly higher when compared to the control group (0.34 vs. 0.26, p = .0001). The median right atrial (RA) reservoir function in patients was significantly reduced compared to controls (30% vs. 36.63%, p = .007). CONCLUSIONS: Shortly after rhythm normalization and restoration of left ventricular EF, using tissue Doppler imaging and two-dimension speckle tracking echocardiography, children who had cardiomyopathy induced by EAT continue to have left ventricular diastolic dysfunction, right ventricular dysfunction, and reduced RA reservoir function.