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Assessment of ventricular function in infants and children. Response to dobutamine infusion
R A Hurwitz1, A Siddiqui, R L Caldwell
1Department of Pediatrics, Indiana University Medical School, Indianapolis.
Insights
Dobutamine infusion effectively assesses ventricular functional reserve in children unable to exercise. This method provides valuable prognostic information for conditions like cardiomyopathy, aiding treatment decisions.
Area of Science:
- Pediatric Cardiology
- Cardiovascular Physiology
- Pharmacology
Background:
- Assessing ventricular functional reserve is crucial for managing pediatric heart conditions.
- Children unable to perform dynamic exercise present a challenge for traditional functional reserve testing.
Purpose of the Study:
- To evaluate a method for assessing ventricular functional reserve in pediatric patients who cannot perform dynamic exercise.
- To determine the safety and efficacy of dobutamine infusion for this purpose.
Main Methods:
- Left ventricular ejection fraction (LVEF) was measured using radionuclide angiocardiography.
- Measurements were taken at rest and during intravenous infusion of dobutamine (5-15 µg/kg/min).
- Arrhythmias were monitored as a potential side effect.
Main Results:
- LVEF significantly increased during dobutamine infusion (0.40 ± 0.21 to 0.49 ± 0.24, P < 0.001).
- No significant difference in LVEF was observed between dobutamine doses of 5 and 10 µg/kg/min.
- Patients on anthracyclines showed improved function with dobutamine, allowing continued chemotherapy.
- Low resting LVEF (<0.40) that did not increase with dobutamine correlated with poor prognosis in dilated cardiomyopathy.
Conclusions:
- Dobutamine infusion is a safe and effective method to assess ventricular functional reserve in pediatric patients unable to exercise.
- This technique provides valuable prognostic information, particularly for patients with cardiomyopathy or those undergoing anthracycline therapy.
- The findings support the use of dobutamine stress testing in pediatric cardiology for risk stratification.
Abstract:
A method to assess ventricular functional reserve in infants and children unable to perform dynamic exercise was evaluated. Left ventricular ejection fraction was measured by radionuclide angiocardiography at rest and during infusion of dobutamine in 5-15 micrograms/kg/min dosages. The only side effects noted were arrhythmias in two patients, who had similar ectopy documented previously. Group left ventricular ejection fraction increased from 0.40 +/- 0.21 to a maximum of 0.49 +/- 0.24 (P less than 0.001). Left ventricular ejection fraction at 5 micrograms/kg/min (0.44 +/- 0.23) was not statistically different from that measured during infusion of dobutamine at 10 micrograms/kg/min (0.48 +/- 0.24). The six patients receiving anthracyclines, who had relatively low function at rest and increased function during dobutamine administration, were continued on their anticancer regimen without deteriorating in condition. Absolute values of left ventricular ejection fraction correlated best with the prognosis in patients with idiopathic dilated cardiomyopathy or structural abnormalities; six out of ten patients whose left ventricular ejection fraction never rose above 0.40 have either died or are in transplant protocols. Thus, study of left ventricular function can be performed easily during dobutamine infusion, generating valuable prognostic information.