Allan H. Rees

Surgical management of infective endocarditis in children

Infective endocarditis occurs infrequently in the general pediatric population, occurring mostly in patients with congenital heart disease. This study reviews our surgical experience with infective endocarditis based on a policy of aggressive intervention, conservative operative debridement, and creative reconstruction options using pericardium and prosthetic heart valves. From 1982 to 1989, 16 patients, 3 weeks to 16 years of age, underwent 19 intracardiac operations for infective endocarditis therapy at Kosair Childrens Hospital. Eight (42%) were for resection of vegetations alone; an additional 11 operations (58%) involved more extensive debridements requiring either valve replacement or valvuloplasty using pericardium for exclusion of an abscess cavity, closure of a fistula, or for valve repair. Operative mortality was 25% (4 patients) and related to preoperative disease severity. There was one late death. Offending organisms included Staphylococcus species (31%), Haemophilus influenzae (13%), pneumococcus (5%), gram-negative organisms (13%), and Candida (13%); no organism grew on culture in 25%. We conclude that aggressive surgical exploration in patients with infective endocarditis is indicated and often requires resection of vegetations alone. More extensive procedures should preserve as much valvular tissue as possible. Pericardium is useful for reconstruction after debridement.

Transtelephonic echocardiography: Successful use in a tertiary pediatric referral center

Recent advances in computers and telecommunications have made transtelephonic echocardiography practical. Our institution is developing a network of transmissional echocardiographic sites at several hospitals in our referral region. We reviewed our initial experience to determine whether transmissional echocardiographic studies (1) gave an appropriate diagnostic impression compared with subsequent videotape review and (2) led to appropriate clinical management (i.e., transfer to a tertiary center or continuation of local care and follow-up). From Aug. 1, 1991, to May 31, 1992, we evaluated 47 transmissional studies (diagnoses: 24 normal, 8 patent ductus arteriosus, 6 ventricular septal defect, 2 pulmonary stenosis, 1 ventricular septal defect with interrupted aortic arch, and 6 miscellaneous). Of 47 studies, 39 (83%) were thought to give accurate diagnostic impressions compared with videotape review. Most inaccuracies were due to the selection and transmission of inconclusive information in an otherwise accurate diagnostic study. Only 1 (2%) of 47 studies resulted in an inappropriate clinical decision; a patients transfer for treatment of a potent ductus arteriosus was delayed 1 day because of an inconclusive transmissional study. We conclude that transmissional echocardiography is useful in the management of pediatric patients with suspected heart disease in a regional referral setting.

Echocardiographic evidence of outflow tract obstruction in Pompe's disease (glycogen storage disease of the heart)

A 7 month old black female infant with the clinical findings of Pompes disease is presented. The diagnosis of an infiltrative myocardiopathy with left ventricular outflow tract obstruction presenting with a pronounced systolic anterior motion of the anterior mitral valve leaflet was made by echocardiography. This diagnosis was confirmed by cardiac catheterization and angiocardiography. Pathologic findings were consistent with Pompes disease (type II glycogen storage disease). The presence of systolic anterior motion of the mitral valve in this patient suggests that this finding is not pathognomonic of idiopathic hypertrophic subaortic stenosis.

Left Atrial-Left Ventricular Bypass for Congenital Mitral Stenosis

The case of a patient with congenital mitral stenosis successfully treated by insertion of a left atrial-left ventricular valved conduit is presented. After insertion of the conduit, pulmonary artery pressure was normal, persistent pulmonary edema and ascites disappeared, and the childs rate of growth and level of activities returned to normal.

An electrocardiographic midterm follow-up study after anatomic repair of transposition of the great arteries

Prospective studies of rhythm and conduction, before and after 1-stage anatomic repair of simple transposition of the great arteries, were performed on 24 survivors. Pre- and postsurgical serial standard electrocardiograms were obtained on each patient. Fourteen patients underwent perioperative 24-hour electrocardiograms; all had follow-up 24-hour electrocardiograms. Rare atrial or occasional ventricular premature complexes were detected in 3 (11%) patients before operation. After surgery, 1 patient developed right bundle branch block. Two patients developed a left bundle branch block. One patient had a QS pattern in V6, which disappeared on follow-up electrocardiogram. Transient second-degree atrioventricular block was detected in 1 patient. A normal P-R interval and P-wave axis were present in all but 1 patient. Mild sinus bradycardia or rare atrial or ventricular premature complexes were detected in 4 of twenty-nine 24-hour electrocardiograms performed in the first 2 years after surgery. At 3 years after repair, 5 patients had a normal 24-hour electrocardiogram and 1 had low-grade ectopy (rare atrial and ventricular premature complexes). At 4 years, all 4 patients studied had normal 24-hour electrocardiograms. During a mean follow-up of 3 years, we have yet to document any symptomatic arrhythmias.

NONINVASIVE EVALUATION OF CARDIOVASCULAR EFFECTS OF PREOPERATIVE SEDATION IN CHILDREN

SummaryThe cardiovascular effects of two premedication regimes used in paediatric anaesthesia were studied. Eleven patients received rectal methohexitone (22 mg·kg) and 11 patients received intramuscular Innovar® (0.03 ml · kg). The effect of these drugs on ventricular function was evaluated by measuring the shortening of the left ventricular minor dimension by echocardiography. No significant changes in this dimension, blood pressure, heart rate or respiratory rate were demonstrated with either drug.Both rectal methohexitone and intramuscular Innovar® were shown to have minimal cardiovascular effects when used as preoperative sedation in paediatric patients. Echocardiography proved to be a valuable technique for the noninvasive evaluation of drug effects on myocardial contractility in children.RésuméNous avons étudié les effets cardiovasculaires de deux prémédications utilisées en pédiatrie. Onze enfants ont reçu du méthohexital par voie rectale (22 mg/kilo) et 11 autres ont reçu par voie intra-musculaire de l’Innovar®, à raison de 0.03 ml/kg. L’effet de ces médicaments sur la fonction ventriculaire a été évalué par la mesure du raccourcissement du diamètre transverse du ventricule gauche à l’échocardiographie.On n’a observé aucun changement significatif de ce diamètre, de la pression artérielle, des fréquences cardiaques et respiratoires, à la suite de l’administration de l’une ou de l’autre des prémédications étudiées. Le méthohexital rectal et l’Innovar® intra-musculaire utilisés comme sédatifs pré-opératoires en pédiatrie ont des effets dépresseurs minimes sur le système car-diovasculaire. L’échocardiographie s’est avérée une technique non-invasive utile pour l’étude des effets des médicaments sur la contractilité myocardique chez l’enfant.

The Prognostic Value of Intraoperative Pressure Gradients with Congenital Aortic Stenosis

Patients with congenital aortic stenosis are subject to sudden death without prior symptoms. Indications for operation are based on pressure gradients, but intraoperative evaluation of results after relief of obstruction can be subjective and arbitrary. Between September, 1981, and October, 1983, 21 patients underwent operation for relief of congenital aortic stenosis. Fifteen had valvular, 4 had supravalvular, and 2 had subvalvular stenosis. Seven patients were 1 year of age or younger, 2 being 3 days old. Preoperative inotropic support and emergency operation were necessary in 2 patients. Intraoperative pressure gradients were measured in all but the 2 patients who were 3 days old. All patients survived without complications. Intraoperative and postoperative pressure gradients were available in 16 patients. The average preoperative pressure gradient was 76 mm Hg. It was significantly lowered to 20 mm Hg (p less than 0.001) intraoperatively, which compared with 15 mm Hg postoperatively. Three patients had an unsatisfactorily high intraoperative pressure gradient after initial intervention. Immediate reexploration and incision of the rudimentary commissure in 2 and excision of redundant valvular tissue in the other resulted in a more satisfactory pressure gradient without substantial aortic insufficiency. We suggest that measurement of intraoperative pressure gradients can accurately assess the results of therapy and allow the surgeon the option of reexploration for further intervention. Moreover, the high correlation between intraoperative and postoperative pressure gradients can help in planning postoperative management and future cardiac catheterizations.