Ventricular mechanics in adolescent and adult patients with a Fontan circulation: Relation to geometry and wall stress

Abstract

Background Patients with single ventricle physiology and Fontan circulation are at increased risk for late complications and reduced survival. The aim of the study was to investigate the correlation between ventricular geometry and systolic regional function in different underlying anatomic conditions in adolescent and adult Fontan‐palliated patients. Method In a retrospective cross‐sectional study, we measured 2D strain, ventricular diameters, ventricular volumes, ejection fraction (EF), global and segmental wall stress, and sphericity index. The same analyses were performed in 99 age‐ and gender‐matched healthy individuals. Results One hundred and one patients were included at a mean age of 21 (range 14–59) years. In comparison with healthy subjects, patients with Fontan circulation displayed larger ventricular volumes (153 ± 78 mL vs 116 ± 38 mL P < 0.05), reduced EF (43% ± 15% vs 55% ± 8% P < 0.05), reduced longitudinal (−13% ± 6% vs −21% ± 4% P < 0.05) and circumferential strain values (−15% ± 7% vs −22% ± 4% P < 0.05). Functionally single ventricles were more spherical (ratio of longitudinal to short‐axis diameters 1.3 ± 0.3 vs 1.7 ± 0.2 P < 0.05). Circumferential strain correlated well with global wall stress and the degree of sphericity (R2 = 0.320), while segmental strain did not correlate with segmental wall stress. The percentage of segments with akinesia was relatively high (16 ± 16% vs 0 ± 0% P < 0.05) indicating reduced segmental contractile function. Conclusion Functionally single ventricles after Fontan palliation have significantly reduced systolic regional and global function with a high intersegmental inhomogeneity. The underlying pathological mechanisms might be multifactorial, including ventricular geometry, sphericity, and regional contractile properties. Future studies are needed to investigate the role of ventricular geometry for clinical performance and outcome.

Serial cardiovascular magnetic resonance feature tracking indicates early worsening of cardiac function in Fontan patients

“…Therefore, inclusion of the septum in CMR strain measurements, as it has been reported up to now, will likely lead to arbitrary and inaccurate representation of ventricular systolic function. Strain analyses in patients with a functionally univentricular heart with inclusion of the hypoplastic ventricle has been described previously using echocardiography speckle tracking analysis [38], however, no direct comparison with the conventional "dominant ventricle only method" was provided.…”

Impact of Right Ventricular Geometry and Left Ventricular Hypertrophy on Right Ventricular Mechanics and Clinical Outcomes in Hypoplastic Left Heart Syndrome

“…"Global strain" was defined as the average of peaksystolic strain-values of the six segments. Due to the lack of normal-values for HLHS patients, we defined hypokinesia according to previous strain-measurements in patients with Fontan-surgery, as peak longitudinal strain values > (weaker than) -8% as hypokinetic 24 . Based on previous studies on patients with transmural myocardial scar tissue values > (weaker than) -4% were defined as akinetic 25 .…”

Complications and management of functional single ventricle patients with Fontan circulation: From surgeon’s point of view

“…The role of increased ventricular dyssynchrony inherently with Fontan patients that is conventionally measured by speckle-tracking echocardiography is increasingly recognized. It was reported that more than 15% of adult Fontan subjects suffered from classic pattern dyssynchrony (10). The ventricular dyssynchrony also varied among Fontan types, worse in AP Fontan in contrast to EC Fontan, probably due to the chronic severe reduction of ventricular preload in the AP Fontan subjects (11).…”

“…The ventricular dyssynchrony also varied among Fontan types, worse in AP Fontan in contrast to EC Fontan, probably due to the chronic severe reduction of ventricular preload in the AP Fontan subjects (11). Both increased ventricular electrical and mechanical dyssynchrony was in part associated with myocardial deformation, myocardial remodeling, and further ventricular systolic or diastolic dysfunction (10,12). Novel imaging modalities like CMR with feature tracking that enables reliable quantification of ventricular mechanics would be helpful to discover the interplay between ventricular dyssynchrony and ventricular dysfunction in Fontan patients.…”