Long-term cardiac sequelae of Kawasaki disease.

Kawasaki disease is the leading cause of acquired heart disease in childhood. Despite treatment with intravenous gamma globulin, 2% to 4% of patients have coronary abnormalities. Those with giant aneurysms are at risk for stenosis and myocardial ischemia/infarction, and require aggressive anticoagulation with frequent follow-up, including stress testing and coronary angiography. In rare cases, patients will have coronary artery bypass grafting. Those with less severe coronary involvement need antiplatelet therapy and infrequent noninvasive testing. Patients with normal echos after the acute phase are not treated, but the future impact of the disease is not certain particularly in the setting of adult onset coronary artery disease.

Recognition and documentation of domestic violence in the clinical setting.

Critical care nurses may encounter a victim of domestic violence or abuse when caring for an individual with traumatic injuries. Understanding the injuries that are associated with acts of violence is only the first step. A vital part of the nurse's responsibilities is the precise written documentation of observations, physical assessments, and other factors that may later become vital evidence in a court of law.

Early recognition of Munchausen Syndrome by Proxy.

In Munchausen Syndrome by Proxy (MSBP), a caregiver fabricates or induces illness in another individual. In most cases, the parent is the perpetrator and the child, the victim. MSBP is a form of child abuse that in extreme cases may result in death. A large percentage of health care providers are not familiar with the syndrome. Early recognition of MSBP is necessary to reduce morbidity and mortality associated with the syndrome.

Shaken baby syndrome.

"Shaken baby syndrome" (SBS) results in intracranial and intraocular hemorrhages with no evidence of external trauma. The cause of these injuries is vigorous shaking of an infant being held by the chest, shoulders, or extremities. A significant number of cases of head trauma in infants and young children are a direct result of SBS. In extreme cases, SBS may result in death. Many cases of SBS go unidentified because of the absence of external injuries, no witnesses to the event, and the failure of the abuser to admit his or her actions. Because of the numbers of children affected and the difficulty in detecting SBS, it is essential that critical care nurses who care for children be aware of SBS as a potentially lethal form of abuse. This article educates nurses about the signs and symptoms of SBS in an attempt to foster early recognition and interventions in cases of SBS to reduce mortality and morbidity associated with the syndrome.

Neonatal radiofrequency catheter ablation of junctional tachycardias.

Junctional tachycardias comprise several arrhythmia types with differing mechanisms, principally involving the region of the atrioventricular (A-V) junction. Neonatal radiofrequency catheter ablation has typically been reserved for life-threatening, drug-refractory cases due to the unique concerns regarding patient size and development. We performed radiofrequency catheter ablation on two neonates with incessant, rapid junctional tachycardias and hemodynamic compromise after failing conventional medical therapy. This report describes 2 neonates who underwent emergent radiofrequency catheter ablation, and compares these two patients to a larger pediatric catheter ablation patient cohort. Both neonates had an acutely successful outcome and were able to be discharged within a week of the ablation procedure. Fluoroscopy time and total procedure time were shorter in these two patients than in the course of the average pediatric catheter ablation. Though long-term developmental consequences of neonatal catheter ablation are yet unknown, in unique extreme situations, radiofrequency catheter ablation can be performed in neonates, as in older children and adults, without excessive acute morbidity.

Proarrhythmia associated with cisapride in children.

BACKGROUND: Cisapride is a prokinetic agent that facilitates gastrointestinal motility and is widely used for the treatment of gastroesophageal reflux disease (GERD) in adults and children. However, reports of ventricular proarrhythmia have been noted in patients taking cisapride, particularly in conjunction with other drugs that may inhibit hepatic metabolism of cisapride via the cytochrome P450 3A4 system. OBJECTIVE: We designed a prospective, blinded study to evaluate the effect of cisapride on ventricular repolarization in children with GERD. METHODS: We analyzed the electrocardiograms (ECGs) from 35 children (age 0.4 to 18 years, mean 5.2 years) including measurement of the resting QT interval (QTc), JT interval (JTc), as well as QT and JT interlead dispersion markers. Data from these patients were compared with ECGs from a control group of 1000 normal children. RESULTS: Eleven (31%) of 35 patients receiving cisapride had a prolonged QTc (> or = 450 ms). The JTc was prolonged > or = 360 ms in 16 of 35 patients (46%). The mean QTc in the cisapride group was 428 +/- 35 ms and mean JTc was 336 +/- 35 ms. An increased QT or JT dispersion (> 70 ms) was seen in only 3 of 35 children. Of the 11 children with QTc prolongation, 2 had documented torsades de pointes ventricular tachycardia. Both patients were taking cisapride concomitantly with a macrolide antibiotic. All other patients were treated with either cisapride alone or in conjunction with other GERD agents, such as ranitidine or omeprazole. CONCLUSIONS: Cisapride may cause prolongation of ventricular repolarization in children. There does not appear to be increased heterogeneity of repolarization or delayed depolarization in this small sample. The proarrhythmia may be exacerbated by medications that inhibit cytochrome P450 3A4 hepatic metabolism, overdosage, or mechanisms that result in decreased serum clearance. ECG intervals should be monitored in children maintained on cisapride, particularly when used in combination with other known QT-prolonging medications.

Effect of pulmonary artery stenoses on the cardiopulmonary response to exercise following repair of tetralogy of Fallot.

Data from exercise tests, echocardiograms, and lung perfusion scans were analyzed to determine whether the excessive minute ventilation (VE) often encountered among patients with tetralogy of Fallot is due to ventilation-perfusion mismatch secondary to branch pulmonary artery stenoses. Patients with branch PA stenoses had lower peak oxygen consumptions and higher VE during exercise than did patients without stenoses, and a strong correlation existed between the degree of pulmonary blood flow maldistribution on lung perfusion scan and the amount of excessive VE during exercise.

Fate of mitral regurgitation following repair of atrioventricular septal defect.

The purpose of this study was to evaluate the fate of mitral regurgitation (MR) following repair of atrioventricular septal defects (AVSDs). Echocardiograms of all survivors of isolated AVSD surgery between 1986 and 1996, who had had > or =2 postoperative color Doppler studies (39 patients), were reviewed. On each study, MR severity was graded on a 1+ to 4+ scale, based upon the size of the MR jet. Median age at surgery was 9 months (range 3 to 169); median age at postoperative follow-up was 45 months (range 3 to 107). Mild deterioration of mitral valve function was fairly common. MR severity increased by > or =1 grade in 16 patients (41%) during the course of the study. However, the deterioration in mitral valve function occurred primarily during the early postoperative time intervals. After the initial 32 postoperative months, MR worsened on only 4 occasions and in each instance worsened by only 1 grade. Deterioration to 4+ MR occurred in only 3 patients, and was not observed after the initial 30 postoperative months. Survival curve analysis predicted a 90% probability of not having severe (4+) MR after 30 months (lower 95% confidence bound: 80%). Postoperative MR remains fairly stable following AVSD repair. Serious deterioration is rare, especially after the initial 30 postoperative months.

Effect of multiple coil closure of patent ductus arteriosus on blood flow to the left lung as determined by lung perfusion scans.

Lung perfusion scans reveal that multiple-coil closure of the ductus does not interfere with pulmonary blood flow. However, caution is necessary when placing multiple coils in small infants.

Electrocardiographic markers of late sudden death risk in postoperative tetralogy of Fallot children.

Following surgery for tetralogy of Fallot (TOF), children may develop late onset ventricular arrhythmias. Many patients have both depolarization and repolarization abnormalities, including right bundle branch block (RBBB) and QT prolongation. The goal of this study was to improve prospective risk-assessment screening for late onset sudden death. Resting ECG markers including QRS duration, QTc, JTc, and interlead QT and JT dispersion were statistically analyzed to identify those patients at risk for ventricular arrhythmias and sudden cardiac death. To determine predictive markers for future development of arrhythmia, we examined 101 resting ECGs in patients (age 12 +/- 6 years) with postoperative TOF and RBBB, 14 of whom developed late ventricular tachycardia (VT) or sudden death. These ECGs were also compared with an additional control group of 1000 age- and gender-matched normal ECGs. The mean QRS (+/- SD) in the VT group was 0.18 +/- 0.02 seconds versus 0.14 +/- 0.02 seconds in the non-VT group (P < 0.01). QTc and JTc in the VT group was 0.53 +/- 0.05 seconds and 0.33 +/- 0.03 seconds compared with 0.50 +/- 0.03 seconds and 0.32 +/- 0.03 seconds in the non-VT group (P = NS). There was no increase in QT dispersion among TOF patients with VT or sudden death compared with control patients or TOF patients without VT, although JT dispersion was more common in the TOF groups. A prolonged QRS duration in postoperative TOF with RBBB is more predictive than QTc, JTc, or dispersion indexes for identifying vulnerability to ventricular arrhythmias in this population, while retaining high specificity. The combination of both QRS prolongation and increased JT dispersion had very good positive and negative predictive values. These results suggest that arrhythmogenesis in children following TOF surgery might involve depolarization in addition to repolarization abnormalities. Prospective identification of high-risk children may be accomplished using these ECG criteria.

Aerobic exercise function of patients with persistent coronary artery aneurysms secondary to Kawasaki disease.

Nine patients with persistent coronary artery aneurysms 1.7-14.0 years after an episode of Kawasaki disease underwent progressive bicycle ergometry with expiratory gas analysis. Two of the patients had aneurysms complicated by angiographically documented coronary artery stenosis. Results of the exercise tests were compared to those obtained from a group of age- and gender-matched normal control subjects. The Kawasaki disease patients did not differ significantly from the control subjects with regard to peak oxygen consumption (81 +/- 7% versus 79 +/- 12% predicted), peak workload (75 +/- 13% versus 77 +/- 9% predicted), anaerobic threshold (21.9 +/- 6.5 versus 18.9 +/- 4.0 ml/kg per minute) or oxygen pulse (96 +/- 7% versus 90 +/- 14% predicted). None of the patients developed significant ST segment changes or rhythm disturbances during exercise. The exercise function of the patients with coronary artery stenosis did not differ from that of patients without stenosis. It was concluded that the aerobic exercise function of patients with persistent coronary artery aneurysms after an episode of Kawasaki disease appears to be well preserved. Kawasaki disease patients with significant coronary artery pathology are not accurately identified by a single assessment of aerobic exercise function.

Stent implantation for relief of pulmonary artery stenosis: immediate and short-term results.

Our objective was to assess the immediate and short-term results of stent implantation to relieve pulmonary artery stenosis (PAS). Thirty-seven patients underwent an attempt at stent implantation at a median age of 7.0 years (range, 0.8-31.4 years) and a median weight of 20.5 kg (range, 7.4-85 kg). Twenty-two patients had previous tetralogy of Fallot repair. A total of 55 stents were implanted successfully in 36 patients. The peak systolic gradient across the stenotic segment decreased from a mean of 43 +/- 20.4 mmHg prestent to 13 +/- 13.9 mmHg (P < 0.001) poststent. The diameter of the narrowest segment increased from a mean of 4.8 +/- 1.6 mm to 10.5 +/- 2.6 mm (P < 0.001). The right ventricular-to-aortic mean systolic pressure ratio decreased from 0.74 +/- 0.2 to 0.52 +/- 0.19 (P < 0.001). Complications included balloon rupture prior to full stent expansion in 4 patients (in 2 patients the stent was positioned in the superior vena cava, and in 2 in the inferior vena cava), distal migration of a stent which was successfully retrieved at surgery 1 mo later in 1 patient, and tethering of the stent to the balloon requiring surgical removal in 1 patient. One patient died several hours after stent placement. Sixteen patients underwent repeat catheterization at a mean follow-up interval of 0.9 +/- 0.5 years (range, 0.2-2.0 years). The mean gradient across the stent for these 16 patients was 26.7 +/- 19.8 mmHg, and there was no change in the mean diameter (9.4 +/- 3.2 mm). Two patients developed stenosis related to neointimal proliferation at the stent site which was redilated successfully. In conclusion, stent implantation is generally safe and effective in relieving PAS.

Excision of a pulmonary valve abscess in a 61-year-old woman with single ventricle.

A 61-year-old woman with levo-transposition of the great arteries, double-inlet single left ventricle, and valvar and subvalvar pulmonary stenosis presented with a large pulmonary valve vegetation unresponsive to antibiotic therapy. The diagnostic evaluation and the surgical management are discussed. At operation the pulmonary valve was excised and an abscess cavity was obliterated with a pericardial patch. She is currently doing well 3 years after the operation.

Superantigens in Kawasaki syndrome.

Kawasaki syndrome (KS) is an acute multisystem vasculitis of infancy and early childhood associated with the development of myocarditis and coronary artery abnormalities. Despite the widely held belief that KS is caused by an infectious agent, there remains considerable controversy over its etiology. Recent immunologic and microbiologic studies suggest a potential role for staphylococcal and streptococcal toxins (superantigens) in the pathogenesis of KS. Confirmation of these findings could result in more effective diagnostic and therapeutic approaches to this common cause of acquired heart disease in children.

Delineation of site, relative size and dynamic geometry of atrial septal defects by real-time three-dimensional echocardiography.

OBJECTIVES: This study attempted to determine the site, relative size and dynamic geometry of atrial septal defects using dynamic three-dimensional echocardiography. BACKGROUND: Recent studies have demonstrated the feasibility of dynamic three-dimensional echocardiography. Images are acquired from computerized reconstruction of sequential, tomographic ultrasound "slices" of the heart. Ultrasound images can be obtained by linear progression of a transducer within a transesophageal imaging probe. In small infants and children the large transducer size has not allowed transesophageal placement, and the probe has been placed on the thorax or in the subcostal position. Other scanning devices, housed in plastic containers, acquire images in a rotational format and can also be placed in a transthoracic or subcostal position. METHODS: Specially designed transesophageal probes and a dedicated computer unit were used for two-dimensional image retrieval and reconstruction of three-dimensional images. Sixteen patients with atrial septal defects were studied (median age 18 months, range 1 day to 18 years). In one patient, images were obtained by transesophageal probe placement; in the other 15 patients, the probe was placed in the transthoracic or subcostal position. RESULTS: A dynamic three-dimensional echocardiogram of the atrial septal defect could be obtained in 13 of the 16 patients. The distinguishing features of the atrial septal defects and their spatial orientation could be visualized in unique three-dimensional views. CONCLUSIONS: Dynamic three-dimensional imaging could be applied to the specific evaluation of atrial septal defects. Unique views of the heart allowed for spatial comprehension of the defects, rendering potentially important clinical information.