Systolic and diastolic functional reserve of the subpulmonary and systemic right ventricles as assessed by pharmacologic and exercise stress: A systematic review.

We performed a systematic review of the literature on the assessment of subpulmonary and systemic right ventricular (RV) functional reserve during pharmacological and exercise stress in congenital heart patients and patients with pulmonary arterial hypertension (PAH). Literature search was conducted using PubMed, EMBASE, and MEDLINE from their inception up to August 2020. Of 913 records identified, 56 studies with a total of 1730 patients were included. Of the 56 studies, 23 assessed subpulmonary RV functional reserve in repaired tetralogy of Fallot patients, 19 assessed systemic RV reserve in patients with transposition of the great arteries (TGA) after atrial switch and those with congenitally corrected TGA, and 14 assessed subpulmonary RV research in patients with PAH. Pharmacological and exercise stress was used, respectively, in 22 and 34 studies. The main findings were (1) impairment of RV systolic and diastolic functional reserve, (2) associations between impaired functional reserve and worse baseline functional parameters, and (3) prognostic implications of RV systolic functional reserve on clinical outcomes in patients with volume and/or pressure-loaded subpulmonary and systemic right ventricles. Further studies are required to establish the incremental value of incorporating stress studies of RV systolic and diastolic function in the clinical management algorithm of congenital heart patients and patients with PAH.

Right Ventricular-Pulmonary Arterial Coupling in Repaired Tetralogy of Fallot.

We assessed right ventricular (RV)-pulmonary arterial (PA) coupling in patients with repaired tetralogy of Fallot (TOF). Sixty patients (34 males) aged 18.6 ± 8.3 years at 14.8 ± 7.4 years after repair and 60 controls were studied. Two-dimensional, tissue Doppler and speckle tracking echocardiography and colour flow mapping were performed to assess RV end-systolic (ESA) and -diastolic areas, tricuspid valve Doppler and myocardial velocities, left ventricular (LV) and RV deformation and pulmonary (PR), tricuspid regurgitation (TR), respectively. The ratios of RV area change to ESA and peak tricuspid annular systolic (s) velocity to RV ESA indexed to body surface area reflected RV-PA coupling. Patients had greater RV areas and reduced tricuspid annular and myocardial velocities, LV and RV myocardial mechanics compared to controls (all p < 0.05). Both RV area change/ESA ratio and peak tricuspid annular s velocity/indexed RV ESA ratio were reduced in patients (all p < 0.001). Sixty-one and 100% of patients had, respectively, RV area change/ESA ratio and peak tricuspid annular s velocity/indexed RV ESA ratio < -2SD of controls. Indices of RV-PA coupling correlated positively with tricuspid myocardial velocities, LV and RV deformation and inversely with PR and TR (all p < 0.05). Multivariate analysis showed RV systolic strain rate, PR and TR as independent predictors of both RV-PA coupling indices, whilst age, gender and LV systolic strain were also predictors of peak tricuspid annular s velocity/indexed RV ESA ratio (all p < 0.05). In conclusion, RV-PA coupling is impaired and is associated with RV and LV mechanics and severity of PR and TR in patients with repaired TOF.