A child with epidermolysis bullosa dystrophica, recessive type (EBDR) developed significant anemia at 9 years of age and was treated with long-term transfusion therapy. At age 17 he had symptoms of congestive heart failure secondary to dilated cardiomyopathy. Treatment with digoxin and vasodilators for the past year has failed to improve his cardiomyopathy significantly. Chronic iron overload and secondary hemosiderosis may have contributed to his problems, and we propose that chelation therapy be used in any child receiving long-term transfusion therapy.
ABSTRACT. Since there are limited studies concerning the hemodynamic effects of verapamil in pediatric patients, cardiovascular effects of clinical doses (100 or 300 pg/kg) of verapamil, given as a 2-min intravenous infusion, were examined in sodium pentobarbital anesthetized swine, aged 1 day (n = 15) and 2 wk (n = 18). Aortic and left ventricular pressures, index of left ventricular contractility, heart rate, and phasic superior mesenteric, renal, and femoral arterial flows were recorded; mean aortic pressure and vascular resistances were calculated. Maximum changes in cardiovascular function (mean %A -C SEM) occurred at the end of the infusion. Mean aortic pressure and index of left ventricular contractility decreased in all animals; responses were larger in magnitude with the higher dose. By 30 min after infusion of 300 pg/kg verapamil had ended, mean aortic pressure in both 1 day and 2 wk olds and index of left ventricular contractility and femoral flow in 1 day olds were still decreased. During infusion of verapamil, heart rate decreased (-11.6 + 2.9) to the high dose in 1 day olds but increased (+6.4 +. 2.7) to 100 and 300 pglkg verapamil in 2 wk olds. After infusion of 300 pglkg verapamil ended, heart rate decreased and reached the nadir (-10.0 f 2.9) by 10 min in 2 wk olds. Decreases in renal resistance (-7.6 f 1.7) were not dose dependent while superior mesenteric resistance decreased (-12.9 2 2.7) only to low dose verapamil in 2 wk olds. In 1 day olds decreases in renal and superior mesenteric resistance were not sustained throughout the infusion. The results indicate that verapamil has both age-and dose-dependent cardiovascular effects in newborn swine and suggest that verapamil be used with caution in infants. (Pediatr Res 20: 428-432, 1986) Abbreviations AoP, aortic pressure -AoP, mean aortic pressure ECG, electrocardiogram HR, heart rate LV, left ventricular LV dP/dt max, index of LV contractility R, resistance iv, intravenous While verapamil is widely used in children and infants for the treatment of supraventricular tachycardia (1-5), adverse effects such as profound hypotension and arterioventricular block have been reported (1, 4, 6, 7). In piglets (aged 18 a 6 days) with hypoxic pulmonary hypertension, verapamil infusion (150 pg/ kg over 2 min) decreased systemic and pulmonary artery pressures (8). In puppies a bolus injection of 400 pg/kg verapamil reduced stroke volume and blood flow velocities in aorta and carotid and femoral arteries (9); these effects were not observed in adult dogs.Since there is little information available concerning the cardiac and regional circulatory effects of verapamil in the newborn period (%-lo), we undertook to study the hemodynamic responses to verapamil in two ages of young swine to further the understanding of the pharmacology of verapamil in pediatrics as a function of postnatal development. MATERIALS AND METHODSAnimal preparation. Two age groups of neonatal swine were used in this study: 1 day (< 24 h old; n = 15) and 2 wk (12-16 days; n = 8). These t...
The capability of the developing intestinal circulation to maintain a vasoconstrictor response during postganglionic adrenergic nerve stimulation or norepinephrine infusion was examined in 34 swine aged 6 h to 2 mo anesthetized with pentobarbital sodium. Aortic and portal venous pressures, electrocardiogram (ECG), and blood flow (F) through the superior mesenteric artery were recorded, and intestinal vascular resistance (MVR) was calculated as mean pressure difference per mean F. Baroreceptor reflex inhibition by bilateral occlusion of the carotid arteries increased MVR, section of the splanchnic nerve and postganglionic fibers decreased MVR, and short-latency F decreases were obtained during mesenteric nerve stimulation (MNS). Latencies for the decreases in F shortened with age and with increasing MNS frequency (5-17 Hz) at any age. Prolonging MNS for 60 s at 10 or 12 Hz led to sustained high MVR in 6-h to 7-day-old animals; however, MVR decreased toward control before the end of the 60-s MNS period in animals 1 to 2 mo old. Intra-arterial infusion of norepinephrine (0.5 microgram X kg-1 X min-1) decreased F and increased MVR in all animals; but by 5 min of infusion, F was returning toward control level in all but the youngest. This demonstration that the least mature intestinal circulation was least capable of autoregulatory escape from vasoconstriction provides further evidence of its functional immaturity.
exercise-induced asthma should be considered in pediatric patients with symptoms of chest pain or dyspnea on exertion; when exercise tests are performed, flow volume loops should be included before and after exercise; maximal exercise tests are unlikely to unmask any cardiovascular abnormalities in such patients.
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