Christopher M. Rausch

Feasibility of Critical Congenital Heart Disease Newborn Screening at Moderate Altitude

BACKGROUND AND OBJECTIVE: Consensus guidelines have recommended newborn pulse oximetry screening for critical congenital heart disease (CCHD). Given that newborn oxygen saturations are generally lower at higher altitudes, the American Academy of Pediatrics and others recommend additional evaluation of the screening algorithm at altitude. Our objective was to evaluate the feasibility of newborn pulse-oximetry CCHD screening at moderate altitude (Aurora, CO; 1694 m). We hypothesized the overall failure rate would be significantly higher compared with published controls. METHODS: We enrolled 1003 consecutive infants at ≥35 weeks’ gestation in a prospective observational study. The nationally recommended protocol for CCHD screening was adhered to with the exceptions of no reflex echocardiograms being performed and providers being informed of results only if saturations were less than predefined critical values. RESULTS: There were 1003 infants enrolled, and 988 completed the screen. The overall failure rate for completed screenings was 1.1% (95% confidence interval: 0.6%–2.0%). The first 500 infants had 1.6% fail, and the last 503 infants had 0.6% fail. Among infants who failed screening, 73% failed secondary to saturations <90%, whereas saturations between 90% and 94%, persistently >3% difference, and multiple criteria were each responsible for 9% of failures. Overall, 1.6% of all infants had incomplete screening and had not passed at the time the test was stopped. CONCLUSIONS: Pulse oximetry screening failure rates at moderate altitude are significantly higher than at sea level. Larger studies with alternative algorithms are warranted at moderate altitudes.

Octreotide treatment of chylothorax in pediatric patients following cardiothoracic surgery

OBJECTIVEnTo analyze the efficacy and safety of octreotide treatment of persistent chylothorax in pediatric patients following cardiothoracic surgery.nnnDESIGNnRetrospective chart review of patients admitted to the cardiac intensive care unit of a tertiary care center over a 10-year period (1998-2008). Nineteen patients were identified who underwent treatment with octreotide for persistent chylothorax following cardiothoracic surgery. We analyzed data regarding age, sex, type of cardiac lesion and surgical procedure, postoperative day octreotide therapy was initiated, maximum drainage prior to and during octreotide therapy, dose range of octreotide, days to resolution, and complications.nnnRESULTSnTwelve patients (63%) experienced resolution of their chylothorax during octreotide treatment. Fourteen patients (74%) demonstrated a decrease in the peak effusion drainage rate following initiation of octreotide therapy, though two of these patients ultimately required further surgical intervention to achieve resolution. Octreotide treatment was associated with unchanged or increased effusion drainage rate in four patients (21%). Patients that responded to octreotide had a lower mean maximal drainage prior to octreotide initiation. Two patients experienced side effects temporally associated with octreotide therapy (transient hypoglycemia and diarrhea). No serious side effects were identified.nnnCONCLUSIONSnOctreotide treatment of chylothorax in combination with dietary modifications in pediatric patients following cardiothoracic surgery resulted in a reduction of peak effusion drainage and eventual resolution in the majority of cases with few and transient side effects.

Ventilatory efficiency slope correlates with functional capacity, outcomes, and disease severity in pediatric patients with pulmonary hypertension☆ , ☆☆ ,★

BACKGROUNDnCardiopulmonary exercise testing is widely used in a variety of cardiovascular conditions. Ventilatory efficiency slope can be derived from submaximal exercise testing. The present study sought to evaluate the relationship between ventilatory efficiency slope and functional capacity, outcomes, and disease severity in pediatric patients with pulmonary hypertension.nnnMETHODSnSeventy six children and young adults with a diagnosis of pulmonary hypertension (PH) performed 258 cardiopulmonary exercise tests from 2001 to 2011. Each individual PH test was matched to a control test. Ventilatory efficiency slope was compared to traditional measures of functional capacity and disease severity including WHO functional classification, peak oxygen consumption, and invasive measures of pulmonary arterial pressures and pulmonary vascular resistance.nnnRESULTSnVentilatory efficiency slope was significantly higher in patients with pulmonary arterial hypertension, with an estimated increase of 7.2 for each increase in WHO class (p<0.0001), compared with normal control subjects (38.9 vs. 30.9, p<0.001). Ventilatory efficiency slope correlated strongly with invasive measures of disease severity including pulmonary vascular resistance index (r =0.61), pulmonary artery pressure (r =0.58), mean pulmonary artery pressure/mean aortic pressure ratio (r =0.52), and peak VO2 (r=-0.58). Ventilatory efficiency slope in 12 patients with poor outcomes (9 death, 3 lung transplant), was significantly elevated compared to patients who did not (51.1 vs. 37.9, p<0.001).nnnCONCLUSIONSnVentilatory efficiency slope correlates well with invasive and noninvasive markers of disease severity including peak VO2, WHO functional class, and catheterization variables in pediatric patients with PH. Ventilatory efficiency slope may be a useful noninvasive marker for disease severity.

Cryothermal Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia in a Pediatric Patient after Atrioventricular Canal Repair

Anatomic displacement of the atrioventricular node and associated conduction tissue in atrioventricular septal defects has been previously described. In spite of the increasing use of cryothermal catheter ablation in the pediatric population, there remains very little literature regarding its use in congenital heart disease. We describe successful cryothermal modification of the slow atrioventricular nodal pathway in a 12-year-old patient with a previously repaired partial atrioventricular septal defect and inducible atrioventricular nodal reentrant tachycardia. The use of a steerable catheter to locate the displaced His signal combined with the use of cryothermal energy allowed for the safe and effective treatment of this patients tachycardia.

Constrictive pericarditis secondary to infection with Mycoplasma pneumoniae.

Pericardial effusions can be insidious, variable in presentation, and may result from a wide variety of causes. We report here a rare case of pericardial effusion in a pediatric patient secondary to infection with Mycoplasma pneumoniae that progressed to cardiac tamponade and constrictive pericarditis. The differential diagnosis of pericardial effusion is reviewed as well as current treatments for pericardial effusions and constrictive pericarditis.

Adherence to Guidelines for Cardiovascular Screening in Current High School Preparticipation Evaluation Forms

We compared the content of the cardiac screening questions on US state high school athletic association preparticipation evaluation forms with current consensus recommendations. We reviewed the high school athletic associations approved, recommended, or required sports preparticipation form from each of the 50 US states and the District of Columbia, and compared the content of the personal and family history components with current recommendations for cardiac screening questions. We found that 85% of the preparticipation forms in current use contain all elements of the formerly recommended guidelines, but only 17% contain all elements of the new consensus guidelines. We conclude that although there appears to be some improvement in the content of the preparticipation forms in current use compared with previous studies, the vast majority of these forms are incomplete compared with current consensus guidelines.

Restrictive lung function in pediatric patients with structural congenital heart disease

OBJECTIVESnWe sought to describe the prevalence of restrictive lung function in structural congenital heart disease and to determine the effect of cardiothoracic surgical intervention.nnnMETHODSnThe data from a retrospective review of the spirometry findings from pediatric patients with structural congenital heart disease were compared with the data from 220 matched controls. Restrictive lung function was defined as a forced vital capacity of <80%, with a preserved ratio of the forced expiratory volume in the first second to forced vital capacity of >80%.nnnRESULTSnOf the children with congenital heart disease, 20% met the criteria for restrictive lung function compared with 13.2% of the controls (Pxa0=xa0.03). The prevalence in those with congenital heart disease without a surgical history was similar to that of the controls (odds ratio, 0.62; 95% confidence interval, 0.34-1.13). Restrictive lung function was more likely if surgical intervention had occurred within the first year of life (odds ratio, 1.96; 95% confidence interval, 1.08-3.55; Pxa0<xa0.0001). Those who had undergone both sternotomy and thoracotomy had a greater prevalence of restrictive lung function than those who had undergone sternotomy or thoracotomy alone (54.2% vs 25.6% and 23.5%, respectively; Pxa0<xa0.0001). The prevalence of restrictive lung function increased significantly with each additional surgical intervention (odds ratio, 1.61; 95% confidence interval, 1.29-2.01; Pxa0<xa0.0001).nnnCONCLUSIONSnRestrictive lung function was more prevalent in those with congenital heart disease after cardiothoracic surgical intervention than in the controls or patients without surgical intervention. The prevalence was also greater with surgical intervention at an earlier age. The risk was equivalent when sternotomy alone was compared with thoracotomy alone but was significantly greater when both sternotomy and thoracotomy werexa0performed. The risk increased with each additional surgery performed.

Axillary Versus Infraclavicular Placement for Endocardial Heart Rhythm Devices in Patients With Pediatric and Congenital Heart Disease

Our objective was to evaluate the implant and mid-term outcomes of transvenous pacemaker or internal cardioverter-defibrillator placement by alternative axillary approaches compared to the infraclavicular approach in a pediatric and congenital heart disease population. We conducted a retrospective review of all patients with new endocardial heart rhythm devices placed at 4 pediatric arrhythmia centers. A total of 317 patients were included, 63 had undergone a 2-incision axillary approach, 51 a retropectoral axillary approach, and 203 an infraclavicular approach. Congenital heart disease was present in 62% of the patients. The patients with the 2-incision axillary approach were younger and smaller. The patients with the retropectoral axillary approach were less likely to have undergone previous cardiac surgery and were more likely to have had an internal cardioverter-defibrillator placed. The duration of follow-up was 2.4 ± 1.9 years for the 2-incision axillary, 2.6 ± 2.6 years for retropectoral axillary, and 3.5 ± 1.4 years for the infraclavicular technique (p = 0.01). No differences were seen in implant characteristics, lead longevity, implant complications, lead fractures or dislodgements, inappropriate internal cardioverter-defibrillator discharges, or device infections among the 3 groups. In conclusion, our data support that the outcomes of axillary approaches are comparable to the infraclavicular approach for endocardial heart rhythm device placement and that axillary approaches should be considered a viable option in patients with pediatric and congenital heart disease.

Toward Improved Cosmetic Results: A Novel Technique for the Placement of a Pacemaker or Internal Cardioverter/Defibrillator Generators in the Axilla of Young Patients

Surgical scars secondary to the placement of pacemakers or internal cardioverter/defibrillators in the infraclavicular area can be unsightly. This report describes a novel cosmetic approach for the placement of pacemakers or internal cardioverter/defibrillators. The approach involves a small infraclavicular incision for placement of the leads and then a larger incision hidden high up in the axilla. The theoretical advantages of this approach are improved cosmetic outcome, ease of subsequent surgeries for device generator changes, and potentially improved defibrillation thresholds.

Moderate altitude is not associated with adverse postoperative outcomes for patients undergoing bidirectional cavopulmonary anastomosis and Fontan operation: A comparative study among Denver, Edmonton, and Toronto

OBJECTIVEnOutcomes of patients with single ventricle physiology undergoing cavopulmonary palliations depend on pulmonary vascular resistance (PVR) and have been suggested to be adversely affected by living at elevated altitude. We compared the pulmonary hemodynamic data in correlation with postoperative outcomes at the 3 centers of Denver, Edmonton, and Toronto at altitudes of 1604, 668, and 103 meters, respectively.nnnMETHODSnHemodynamic data at pre-bidirectional cavopulmonary anastomosis (BCPA) and pre-Fontan catheterization between 1995 and 2007 were collected. Death from cardiac failure or heart transplantation in the same period was used to define palliation failure.nnnRESULTSnThere was no significant correlation between altitude (ranged from 1 to 2572 meters) and PVR, pulmonary artery pressure (PAP) or transpulmonary gradient (TPG) at pre-BCPA and pre-Fontan catheterization. BCPA failure occurred in 11 (9.2%) patients in Denver, 3 (2.9%) in Edmonton, and 34 (11.9%) in Toronto. Fontan failure occurred in 3 (6.1%) patients in Denver, 5 (7.2%) in Edmonton, and 11 (7.0%) in Toronto. There was no significant difference in BCPA and Fontan failure among the 3 centers. BCPA failure positively correlated with PVR and the presence of a right ventricle as the systemic ventricle. Fontan failure positively correlated with PAP and TPG.nnnCONCLUSIONSnModerate altitude is not associated with an increased PVR or adverse outcomes in patients with a functional single ventricle undergoing BCPA and the Fontan operation. The risk factors for palliation failure are higher PVR, PAP, and TPG and a systemic right ventricle, but not altitude. Our study reemphasizes the importance of cardiac catheterization assessments of pulmonary hemodynamics before BCPA and Fontan operations.