Regional ventricular wall motion abnormalities in tricuspid atresia after the Fontan procedure: flawed methodology may lead to a spurious finding of hypokinesia

We believe that the two-frame method described by Akagi et al. cannot adequately describe the highly abnormal wall motion characteristics of these post-Fontan ventricles, and the systolic hypokinesia they describe may be spurious. Our data show that the predominant abnormality is incoordinate relaxation of the ventricular wall, which in turn prolongs the time constant of relaxation and the isovolumetric relaxation time and leads to reduced early rapid filling. Indeed, it was these abnormalities of diastolic, not systolic, function that were the strongest predictor of poor exercise performance in our study of patients late after the Fontan procedure. We strongly believe that the analysis of ventricular wall motion requires sequential data throughout the cardiac cycle, with well defined reference points concerning the timing of cardiac events, so that misinterpretation can be avoided.