Idiopathic restrictive cardiomyopathy in childhood: diagnostic features and clinical course.

OBJECTIVE: To describe the clinical course and outcome of children with idiopathic restrictive cardiomyopathy (IRCM) and to present the Doppler echocardiographic features of this disease in childhood.
DESIGN: We reviewed the Mayo Clinic patient database for the period from 1975 to 1993 to identify children who underwent assessment for IRCM.
MATERIAL AND METHODS: Clinical records and diagnostic studies, including two-dimensional (2-D), M-mode, and Doppler echocardiograms, were reviewed for each patient. Characteristics were analyzed statistically to determine potential predictors of outcome.
RESULTS: Eight children (five girls and three boys) were diagnosed with IRCM between 1975 and 1993 at our institution. The median age at diagnosis was 11 years, and the median duration of follow-up was 11.5 years. Of the eight patients, five died (the median time from initial examination to death was 1 year). All five of these patients had clinical and radiographic evidence of pulmonary venous congestion. In all patients, 2-D and M-mode echocardiography revealed atrial enlargement without ventricular dilatation or hypertrophy. The four patients who underwent detailed diastolic Doppler assessment had findings consistent with restrictive filling and increased left ventricular end-diastolic pressure: (1) short mitral deceleration time, (2) increased pulmonary vein atrial reversal velocity and duration, and (3) pulmonary vein atrial reversal duration greater than mitral A-wave duration.
CONCLUSION: The prognosis for children with IRCM is poor. In this small group of patients, absence of pulmonary venous congestion most consistently predicted extended survival. A combined 2-D and Doppler echocardiographic examination provides a reliable noninvasive means of assessing the physiologic and morphologic features of IRCM in children.