Pulmonary blood flow in children with univentricular heart and unilateral diaphragmatic paralysis

Abstract

Objectives Spontaneous breathing has an important effect on pulmonary arterial blood flow in patients with Glenn/Fontan circulation. Unilateral diaphragmatic paralysis is a frequent complication after heart surgery in congenital heart disease. The aim of this study was to investigate the influence of unilateral diaphragmatic paralysis on blood flow distribution in the pulmonary arteries with Glenn/Fontan circulation. Patients/Methods Magnetic resonance phase-contrast imaging was used to evaluate stroke volume index in the left and right pulmonary arteries in patients with Glenn/Fontan circulation with unilateral diaphragmatic paralysis. Data for 18 patients with univentricular heart and unilateral diaphragmatic paralysis were analysed, eight in the Glenn stage and ten in the Fontan stage. Ten patients had right-sided diaphragmatic paralysis, and eight had left-sided diaphragmatic paralysis. A diaphragmatic plication was performed in seven patients. The control group consisted of 36 patients with Glenn (n = 16)/Fontan (n = 20) circulation without diaphragmatic paralysis. Results In both left- and right-sided diaphragmatic paralysis, the stroke volume index to the ipsilateral side was significantly lower than in controls (2.81 (1.45–4.50) ml/m2 left vs 11.97 (7.36–16.37) ml/m2 in controls, P < 0.0002; 8.2 (4.49–12.64) ml/m2 with right vs 12.64 (9.66–16.61) ml/m2 in controls; P = 0.0284). The stroke volume index to the contralateral side showed a slight but non-significant increase in the presence of unilateral diaphragmatic paralysis. Conclusions Unilateral diaphragmatic paralysis in patients with Glenn/Fontan circulation has a negative impact on pulmonary arterial stroke volume index on the side of the paralysis.