Classic-Pattern Dyssynchrony in Adolescents and Adults With a Fontan Circulation.

BACKGROUND Previous studies have suggested the presence of dyssynchrony in the functionally single ventricle. The aim of this study was to investigate the presence of classic-pattern dyssynchrony (CPD), characterized by typical early and late deformation of opposite walls, and its relation to QRS duration and myocardial function in patients with single-ventricle physiology after Fontan palliation. METHODS In a retrospective cross-sectional study, 101 adolescent and adult patients with single-ventricle physiology after the Fontan procedure were investigated. Strain curves were visually assessed for the presence of CPD. Systolic and diastolic function were assessed using echocardiography. RESULTS One hundred one patients were included, with varying anatomic morphology: two sizable ventricular components (n = 21), right dominant (n = 21), left dominant (n = 49), and undefined anatomy (n = 10). Fifteen of 101 Fontan patients had CPD. Forty-three percent of patients with two sizable ventricular masses displayed CPD, mostly with prolonged QRS, while the number of patients with CPD with right-dominant (9%) and left-dominant (6%) morphology was significantly lower (P = .016). Those with CPD displayed significantly (P < .05) larger QRS widths (142 ± 22 vs 112 ± 24 msec), lower ejection fractions (31 ± 14% vs 45 ± 14%), lower global early diastolic strain rates (0.7 ± 0.5 vs 1.2 ± 0.8 sec-1), and global systolic circumferential (-10 ± 5% vs -16 ± 7%) and longitudinal (-9 ± 5% vs -14 ± 5%) strain, respectively. CONCLUSIONS CPD is present in a proportion of adolescent and adult patients after Fontan palliation. The presence of CPD is associated with reduced systolic and diastolic function compared with Fontan patients without CPD. Because the presence of CPD appears to be a promising predictor for response to cardiac resynchronization therapy in patients with biventricular circulation, these findings may have important potential for prospective evaluation of cardiac resynchronization therapy in patients with univentricular circulation.