Pediatric cardiology
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Pediatric cardiology · Sep 2002
Predictors of refractory tachycardia in infants with supraventricular tachycardia.
Reentrant supraventricular tachycardia (SVT) is the most common arrhythmia in infants. There are few predictors as to which patients will have recurrent or refractory SVT. We retrospectively reviewed records of all infants with SVT evaluated at The Hospital for Sick Children, Toronto, between January 1, 1995, and December 31, 1999. ⋯ There were no differences between the groups in gender, cycle length in SVT or sinus rhythm, the presence of pre-excitation, initial medication choice, or duration of therapy. Recurrent SVT in infancy is associated with younger age and/or ventricular dysfunction at presentation and also with slower ventriculoatrial conduction. The similar duration of therapy for simple and complex patients suggests that the early clinical course of SVT in infancy is not predictive of long-term outcome.
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Pediatric cardiology · Sep 2002
Value of the new Doppler-derived myocardial performance index for the evaluation of right and left ventricular function following repair of tetralogy of fallot.
The systolic and diastolic function in both ventricles may be altered even after successful corrective surgery of tetralogy of Fallot. The aim of this study was to assess the combined diastolic and systolic function of both ventricles using the Doppler-derived myocardial performance index (MPI) in patients with operated tetralogy of Fallot (TOF). We performed a prospective analysis of 51 patients following corrective surgery of TOF: 21 had a subannular patch, 20 had a homograft implantation at initial operation, and 10 were reoperated with secondary homograft implantation. ⋯ The noncompliant right ventricle may shorten the right ventricular isovolumetric relaxation time, resulting in a paradoxically low right MPI. This may reduce the sensitivity of the index in recognizing patients with right ventricular dysfunction following corrective surgery of TOF. Additional diastolic impairment occurs in patients with right ventricular volume overload.
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Pediatric cardiology · Sep 2002
Expression of adenylyl cyclase V/VI mRNA and protein is upregulated in cyanotic infant human myocardium.
We have previously demonstrated that both basal and isoproterenol-stimulated activities of myocardial adenylyl cyclase were greater in cyanotic patients with tetralogy of Fallet (TOF) than those in acyanotic patients. However, it was not determined whether increased enzyme activity was related to a similar increase in adenylyl cyclase protein and mRNA expression. In the current study, we examined the mRNA and protein expression of cardiac adenylyl cyclase, types V and VI, in cyanotic and acyanotic patients with TOF. ⋯ Protein expression of both V and VI adenylyl cyclases was correspondingly upregulated in cyanotic patients compared to acyanotic patients. Our results indicate that gene and protein expression of cardiac adenylyl cyclases, types V and VI, is increased in the cyanotic myocardium. These results suggest that chronic hypoxemia may regulate the expression of adenylyl cyclase enzymes.
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Pediatric cardiology · Jul 2002
Randomized Controlled Trial Comparative Study Clinical TrialSystemic inflammatory response related to cardiopulmonary bypass and its modification by methyl prednisolone: high dose versus low dose.
The objective of our study was to investigate the safety and efficacy of high-dose methyl prednisolone (MP) in modifying the systemic inflammatory response (SIR) to cardiopulmonary bypass (CPB) and to compare its efficacy with low-dose MP in children undergoing cardiac surgery for congenital heart disease. Thirty children with congenital heart disease undergoing CPB were randomly assigned to two groups: group 1 (n = 15) received 30 mg/kg MP by an intravenous infusion for 30 minutes and group 2 (n = 15) received 2 mg/kg intravenously, before the onset of CPB. Postoperative clinical parameters were recorded, and serum interleukin (IL)-6 and 8 levels, acute phase reactants, and blood biochemistry were determined serially for both groups. ⋯ Although postoperative IL and CRP levels indicated a SIR in our patients, the clinical picture was apparently affected in only 1 patient and she was in the high-dose MP group. CPB initiates a SIR that is associated with an increase in neutrophil count, CRP, and IL-6 and 8 levels. High-dose (30 mg/kg) MP was not superior to low-dose (2 mg/kg) in blunting the SIR to CPB in pediatric patients undergoing open-heart surgery.