Introduction

Conventional echographic parameters are neither accurate nor reproducible to assess left ventricular function after cardiac surgery with cardiopulmonary bypass. The main objective of this study was to evaluate the feasibility and reproducibility of 2D strain during the peri-operative period. The second objective was to assess the post-operative evolution of 2D strain, particularly after an atrial septal defect closure.

Methods

33 pediatric patients (< 18 years) with congenital heart disease undergoing cardiac surgery with cardiopulmonary bypass were included in this prospective single center study. Daily echocardiography was performed from the day before surgery to the sixth post-operative day. Left ventricular ejection fraction (Teichholz and Simpson) and 2D strain (longitudinal, circumferential and radial) were measured.

Results

Mean age and weight were 4 years [2–6] and 15 kg [10–20]. Mean durations of cardiopulmonary bypass and aortic cross-clamp were 117 min [86–148] and 58 min [44–72]. The global post-operative feasibility of longitudinal, circumferential and radial strain was respectively 91%, 95% and 95%, similar to the feasibility of conventional parameters (97%). The intra- and inter-observer correlation coefficients were good for longitudinal strain (0.916, P < 0.001 and 0.885, P < 0.001), circumferential strain (0.880, P < 0.001 and 0.829, P < 0.001) and radial strain (0.701, P = 0.002 and 0.559, P = 0.020). Early post-operative circumferential strain was correlated to the durations of aortic cross-clamp ( r = 0.603, P = 0.001), inotropic support ( r = 0.558, P = 0.004) and mechanical ventilation ( r = 0.580, P = 0.002). Circumferential strain significantly improved after an atrial septal defect closure (−19.86 [−22.73; −17.00] versus −14.95 [−17.79; −12.11], P = 0.028).

Conclusion

2D strain is feasible and reproducible in the post-operative period. Further studies are needed to assess its interest in early diagnosis of post-operative myocardial dysfunction.