Considerations in pursuing the optimal timing for pulmonary valve replacement in repaired tetralogy of Fallot

The right ventricular myocardial systolic-to-diastolic duration ratio in children after surgical repair of Tetralogy of Fallot

“…Because the myocardial S/D duration ratio incorporates systolic and diastolic factors, including preejection, ejection, PSS and diastolic durations, as well as lateral wall-septal inefficiency, it provides a comprehensive assessment of myocardial inefficiency and dysfunction in the rTOF RV (17). As with almost all functional parameters, the myocardial S/D duration ratio is expected to be impacted by loading conditions and contractility, thereby reflecting myocardial performance in response to its loading (16,18,25). Indeed, whereas the myocardial S/D duration index was not statistically associated with parameters of RV remodeling in rTOF, including RVEDVI, pulmonary regurgitation, and RVOT gradient, this does not indicate load independency of the index, since volume and pressure loading can prolong ventricular systole thus increasing the S/D duration ratio (6).…”