Standard volume infusion unmasked diastolic dysfunction in pediatric heart transplant recipients during surveillance cardiac catheterization, but without echocardiographic correlates

Background Adult experience evaluating left ventricular diastolic function (LVDFx) includes volume administration during catheterization while obtaining pulmonary capillary wedge pressures (PCWP) or left ventricular end diastolic pressures (LVEDP). Catheterization is inherently challenging in pediatric patients, making echocardiographic assessment ideal. Pediatric echocardiographic studies predicting LVDFx have variable hemodynamic and hydration conditions and have produced inconsistent results. We evaluated the association between simultaneous echocardiographic and catheterization assessment of LVDFx, using a fluid bolus for optimal loading conditions. Methods Prospective cohort study of pediatric heart transplant recipients receiving echocardiogram simultaneous with routine cardiac catheterization. Mitral valve inflow velocities, septal and lateral wall tissue Doppler indices, and PCWP and/or LVEDP were obtained and repeated following a 10 ml/kg bolus. Echocardiographic parameters were evaluated for an association with changes in PCWP or LVEDP following the bolus. Abnormal LVDFx was defined as PCWP or LVEDP >= 12 mm Hg. Results Twenty-nine patients underwent catheterization. Median pre-bolus PCWP and LVEDP were 11.0 mm Hg and 10.0 mm Hg, respectively. After bolus, median PCWP and LVEDP increased to 14.0 mm Hg (p < .001) and 13 mm Hg (p < .001), respectively. Of 21 patients with normal pre-bolus catheterization hemodynamics, 14 (66.7%) increased to abnormal following fluid bolus. Using area under an ROC, no echocardiographic parameter of LVDFx, or their ratios, were associated with predetermined abnormal LVEDP and/or PCWP. Conclusion After bolus, our cohort demonstrated significant increases in LVEDP and/or PCWP, unmasking diastolic dysfunction. Fluid challenges should be considered in pediatric patients undergoing cardiac catheterization with suspected diastolic dysfunction. Echocardiographic measurements were unable to discriminate between normal and abnormal LVEDP and/or PCWP.