The left ventricle in atrial septal defect: Looking through 3D glasses.

OBJECTIVES: To identify left ventricular (LV) dyssynchrony and associated factors in atrial septal defect (ASD) patients, using real time three-dimensional echocardiogram (RT3DE).

BACKGROUND: Left ventricular dysfunction has been observed in ASD. Few studies have utilized RT3DE to assess LV wall-motion abnormality in ASD.

METHODS: Patients aged ≥1 year with ASD, with or without partial anomalous pulmonary venous drainage (PAPVD), were included over 1 year. Additional cardiac defects or abnormalities independently affecting LV function were excluded. 2DE and RT3DE-derived LV function data were recorded. Student's t test and Pearson's correlation were used for analysis.

RESULTS: Of 104 patients (69 females) aged 1-57 years, ostium secundum ASD was present in 97 and sinus venosus ASD in 7. Maximum excursion increased significantly with age, weight, and body surface area (P < 0.001). Majority of children (58%) aged 3-5 years showed no delay in segmental excursion. Lateral wall excursional delay was greater beyond 5 years or with weight > 15 kg (42% as compared to 20% in <15 kg). In patients weighing < 15 kg, time to minimum systolic volume (Tmsv 16-SD) was higher with PAPVD and with indexed defect size > 40 mm/m2 , though not statistically significant. As compared to EF estimation by 2DE, EF derived using RT3DE was significantly lower (P < 0.001).

CONCLUSION: Left ventricular dyssynchrony is least between 3 and 5 years. Beyond 5 years, delayed lateral wall excursion is seen. With an indexed defect size exceeding 40 mm/m2 , and in the presence of PAPVD, time to minimum systolic volume is higher.