Sodium abnormalities

Review article: NEJM 2015;372:55-65.

Disorders of Plasma Sodium - Causes, Consequences, and Correction.

Sterns RH.

Abstract

This review considers the causes and consequences of an abnormal plasma sodium concentration and offers a framework for correcting it.

PMID:

 

25551526

 

[PubMed - as supplied by publisher]

Acute Kidney Injury detection after heart surgery in children

JACC 2014;64:2753-62

Combining functional and tubular damage biomarkers improves diagnostic precision of acute kidney injury after cardiac surgery.

Rajit K. Basu, et al. JACC 2014;64:2753-62.

Objective: Combining two biomarkers will improve precision of acute kidney injury (AKI) diagnosis after heart surgery in children.

Methods: n=345 children after cardiopulmonary bypass (CPB). Two biomarkers: Plasma Cystatin C & uNGAL were measured 2 hr after initiation of CPB.

Conclusion: Composites of plasma Cystatin C and uNGAL are superior to serum creatinine for predicting discrete characteristics of AKI.

(Click on the image to enlarge)

ICU: NGAL to detect Acute Kidney Injury

JACC 2011;57:1752-61

Article

ICU: Prolonged stay after cardiac surgery

Eur J Cardiothorac Surg. 2011 Jan 10. [Epub ahead of print]

Predictors of long intensive care unit stay following cardiac surgery in children.

Pagowska-Klimek I, Pychynska-Pokorska M, Krajewski W, Moll JJ.
The Department of Anesthesiology and Intensive Care, Polish Mother's Memorial Hospital Institute, Lodz, ul. Rzgowska 288/293, Poland.

Objective: Prolonged length of stay in intensive care units after congenital heart disease surgery is associated with poor outcome, places a considerable burden on the financial resources of hospitals, and is an organizational challenge as well. This research discusses the impact of perioperative factors on prolonged stay in intensive care units.

Methods: This is a retrospective study examining the determinants of prolonged intensive care length of stay in 693 children after cardiac surgery. Univariate and multivariate analyses were performed for an intensive care unit stay over 3 and over 14 days.

Results: Neonatal age, preoperative mechanical ventilation and preoperative myocardial dysfunction, complexity and duration of procedures, as well as postoperative complications (low cardiac output syndrome, bleeding, re-operation, acute kidney injury, sepsis, respiratory insufficiency, pulmonary hypertension, pneumothorax, postoperative cardiac arrest, pneumonia, and delayed sternum closure) prolong intensive care unit hospitalization over 3 days. Patients with acute kidney injury requiring renal replacement therapy, pneumothorax, pulmonary hypertension, need for re-operation during the same admission, and myocardial dysfunction prior to surgery are at high risk of intensive care unit stay over 14 days.

Conclusions: Some patients with a risk of prolonged hospitalization may be identified preoperatively, the others just after the operation. Optimizing preoperative status and aggressive treatment of complications may have significant influence on the duration of hospitalization in intensive care units. The knowledge of risk factors may facilitate organizational procedures and rational bed management.

Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

ICU: ECMO + CRRT Outcome

Pediatric Critical Care Med 2011;12:153-8
Conclusions: (i) No evidence that CRRT with ECMO leads to chronic renal failure any more than CRRT does on its own. (ii) Mortality is higher for CRRT+ECMO than ECMO alone & is similar to patients receiving CRRT without ECMO.

ICU: Hypoventilation strategy after Glenn Operation

Scott Bradley et al. JTCVS 2003;126:1033-9

See entry in PediCardiology.

Diuretics - High dose vs. Low dose (Adult study)

Diuretic Strategies in Patients with Acute Decompensated Heart Failure
G. Michael Felker, M.D., et al. for the NHLBI Heart Failure Clinical Research Network
N Engl J Med 2011; 364:797-805
March 3, 2011

Background
Loop diuretics are an essential component of therapy for patients with acute decompensated heart failure, but there are few prospective data to guide their use.

Methods
In a prospective, double-blind, randomized trial, we assigned 308 patients with acute decompensated heart failure to receive furosemide administered intravenously by means of either a bolus every 12 hours or continuous infusion and at either a low dose (equivalent to the patient's previous oral dose) or a high dose (2.5 times the previous oral dose). The protocol allowed specified dose adjustments after 48 hours. The coprimary end points were patients' global assessment of symptoms, quantified as the area under the curve (AUC) of the score on a visual-analogue scale over the course of 72 hours, and the change in the serum creatinine level from baseline to 72 hours.

Results
In the comparison of bolus with continuous infusion, there was no significant difference in patients' global assessment of symptoms (mean AUC, 4236±1440 and 4373±1404, respectively; P=0.47) or in the mean change in the creatinine level (0.05±0.3 mg per deciliter [4.4±26.5 μmol per liter] and 0.07±0.3 mg per deciliter [6.2±26.5 μmol per liter], respectively; P=0.45). In the comparison of the high-dose strategy with the low-dose strategy, there was a nonsignificant trend toward greater improvement in patients' global assessment of symptoms in the high-dose group (mean AUC, 4430±1401 vs. 4171±1436; P=0.06). There was no significant difference between these groups in the mean change in the creatinine level (0.08±0.3 mg per deciliter [7.1±26.5 μmol per liter] with the high-dose strategy and 0.04±0.3 mg per deciliter [3.5±26.5 μmol per liter] with the low-dose strategy, P=0.21). The high-dose strategy was associated with greater diuresis and more favorable outcomes in some secondary measures but also with transient worsening of renal function.

Conclusions
Among patients with acute decompensated heart failure, there were no significant differences in patients' global assessment of symptoms or in the change in renal function when diuretic therapy was administered by bolus as compared with continuous infusion or at a high dose as compared with a low dose. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00577135.)

Editorial on the above article:
Comparative Effectiveness of Diuretic Regimens
Gregg C. Fonarow, M.D.
N Engl J Med 2011; 364:877-878
March 3, 2011

Acute decompensated heart failure is associated with substantial morbidity, mortality, and health care expenditures.1 Most patients present with symptoms related to fluid overload, which may be complicated by concomitant renal dysfunction.2 Treating the signs and symptoms of heart failure while preserving or improving renal function is a crucial therapeutic goal.
For more than five decades, the administration of intravenous loop diuretics has been the mainstay of therapy to reduce congestion, decrease ventricular filling pressures, and improve symptoms of heart failure, with such therapy becoming an empirically accepted standard of care for this condition.1,3,4 However, there is little evidence . . .

Use of Procalcitonin in Newborn to determine length of antibiotic therapy

BMC Pediatrics 2010

Martin Stocker , Wim JJ Hop and Annemarie MC van Rossum

BMC Pediatrics 2010, 10:89

Published:	8 December 2010

Abstract (provisional)

Background

Early diagnosis and treatment of the newborn infant with suspected sepsis are essential to prevent severe and life threatening complications. Diagnosis of neonatal sepsis is difficult because of the variable and nonspecific clinical presentation. Therefore, many newborns with nonspecific symptoms are started on antibiotic treatment before the presence of sepsis has been proven. With our recently published single-centre intervention study we were able to show that Procalcitonin determinations allowed to shorten the duration of antibiotic therapy in newborns with suspected early-onset sepsis.

Methods

The study is designed as randomized controlled international multicenter intervention trial on the efficacy and safety of Procalcitonin guided treatment. Term and near-term infants (gestational age greater than or equal to 34 0/7 weeks) with suspected sepsis in the first 3 days of life requiring empiric antibiotic therapy will be included. The duration of antibiotic therapy in the standard group is based on the attending physician's assessment of the likelihood of infection (infection unlikely, possible, probable or proven). In the Procalcitonin group, if infection is considered to be unlikely or possible, antibiotic therapy is discontinued when two consecutive Procalcitonin values are within the normal range. Co-primary outcome measures are the duration of antibiotic therapy (superiority aspect of the trial) and the proportion of infants with a recurrence of infection requiring additional courses of antibiotic therapy and/or death in the first month of life (safety of study intervention, non-inferiority aspect of the trial). The number of infants to be included equals 800 per arm. With these numbers the power of the study to demonstrate superiority for duration of antibiotic therapy as well as non-inferiority regarding safety, i.e. excluding a disadvantage difference larger than 2% for the experimental arm, will both be greater than 80%.

Discussion

Benefit of the study is a possible limitation of unnecessary use of antibiotics. The results of our first study suggest that there is a low risk on discontinuing antibiotic treatment too early, resulting in the development of a neonatal infection with its morbidity and mortality. Trial registration: This trial is registered in the U.S. National Institutes of Health's register, located at http://www.clinicaltrials.gov. (NCT00854932).

From Introduction:

Another biomarker that has been discovered more recently, PCT, is proven to be a good marker of severe, invasive bacterial infections in children. All studies on severe, invasive bacterial infections in children report higher sensitivities and specificities of PCT than for CRP [12-16]. PCT is a 116–aminoacid peptide and one of the precursors of calcitonin. The physiological function of calcitonin remains unknown. No disorders attributable to either an excess or a deficiency of calcitonin have been identified. Most microbial infections induce a ubiquitous increase in CALC1 gene expression and a subsequent release of calcitonin precursors from all tissues and cell types throughout the body [17]. In bacterial infections, PCT increases from concentrations in the picogram range (below the detection level of current PCT assays) to plasma concentrations ranging from 1 to 1000 ng/ml. This increase often correlates with the severity of the disease and with mortality [18-21]. Increases in PCT occur more rapidly than increases in CRP. PCT can be detected in the plasma 2 hours after the injection of endotoxins. Within 6–8 hours, PCT concentrations rise and a plateau is reached after approximately 12 hours [22]. CRP can be detected in the plasma after 12 h and reaches a plateau after 20–72 hours. PCT and CRP decrease to their normal values after 2–3 days and 3–7 days, respectively [23-25].

The use of PCT as a marker of neonatal bacterial infection is complicated by several factors. First, infants with respiratory distress syndrome, hemodynamic failure, perinatal asphyxia, intracranial hemorrhage, pneumothorax, or after resuscitation have raised serum PCT concentrations that do not differ from those of septic neonates up to 48 h after onset of clinical signs of distress or infection [26-28]. Second, a physiological increase of PCT has been reported up to 48 h post partum [29]. Third, prepartum and intrapartum administration of antibiotics may affect PCT concentrations in the umbilical cord [30], and postnatal administration of antibiotics will decrease PCT concentrations more rapidly than CRP concentrations [31,32]. When these pitfalls are taken into account, PCT performs better than CRP in diagnosing neonatal bacterial infection.

Chiesa et al developed a nomogram for PCT [33] and Assumma and colleagues performed a longitudinal study on PCT values in healthy neonates [34]. In his findings Chiesa was able to report two major differences in between healthy and septic neonates which formed the basis of his nomogram. Firstly, the level of elevation in PCT was much higher in septic neonates versus healthy newborns and secondly, the absence of a decrease of PCT values after the initial cytokine release post-partum is indicative of a bacterial infection. With all PCT values being increased during the first two days of life, a reference range covering this time period with intervals of several hours is a tool to identify septic neonates. The adult reference ranges apply from three days after birth. Using PCT in this manner has been proven extensively to be a very reliable marker for the diagnosis of neonatal sepsis [35-39].

In recent years a novel indication for the use of PCT has been discovered, related to its described high negative value. It has been reported in many interventional trials [40-44] that a low PCT indicates the absence of a need for antimicrobial therapy. In several countries the recent adult intensive care guidelines have been altered to the extent that PCT has displaced CRP in the recommendations [45,46]. Applying this principle to neonatology, we performed a single-centre intervention trial in Lucerne, Switzerland that showed that serial PCT determinations allowed to shorten the duration of antibiotic therapy in term and near-term infants with suspected early-onset sepsis [47]. This study is designed to test the reliability of a PCT-based strategy in a larger cohort of neonates.

And, read on from the link.

Direct link to journal article on www.

Diuretics: Sequential blockade (Diuril-Lasix) "misconception"

JACC 2010;56:1527-34

Combination of Loop Diuretics With Thiazide-Type Diuretics in Heart Failure

Jacob C. Jentzer, MD,Tracy A. DeWald, RD, PharmD, BCPS andAdrian F. Hernandez, MD

Volume overload is an important clinical target in heart failure management, typically addressed using loop diuretics. An important and challenging subset of heart failure patients exhibit fluid overload despite significant doses of loop diuretics. One approach to overcome loop diuretic resistance is the addition of a thiazide-typediuretic to produce diuretic synergy via "sequential nephron blockade," first described more than 40 years ago. Although potentially able to induce diuresis in patients otherwise resistant to high doses of loop diuretics, this strategy has not been subjected to large-scale clinical trials to establish safety and clinical efficacy. We summarize the existing literature evaluating the combination of loop and thiazide diuretics in patients with heart failure in order to describe the possible benefits and hazards associated with this therapy. Combinationdiuretic therapy using any of several thiazide-type diuretics can more than double daily urine sodium excretion to induce weight loss and edema resolution, at the risk of inducing severe hypokalemia in addition to hyponatremia, hypotension, and worsening renal function. We provide considerations about prudent use of this therapy and review potential misconceptions about this long-used diuretic approach. Finally, we seek to highlight the need for pragmatic clinical trials for this commonly used therapy.

Ethics & Training: Time to stop.

PCCM Perspective
In think it is time to stop
Annie Janvier MD, PhD.
Pediatr Crit Care Med 2010;11:624-5.

An article about including "stopping" CPR in the training for CPR.

ICU: ECMO for CPR

Circulation. 2010;122:S241-S248

Rapid-Response Extracorporeal Membrane Oxygenation to Support Cardiopulmonary Resuscitation in Children With Cardiac Disease

David A. Kane, MD; Ravi R. Thiagarajan, MBBS, MPH; David Wypij, PhD; Mark A. Scheurer, MD; Francis Fynn-Thompson, MD; Sitaram Emani, MD; Pedro J. del Nido, MD; Peter Betit, RRT; Peter C. Laussen, MBBS

Background—Survival of children with in-hospital cardiac arrest that does not respond to conventional cardiopulmonary resuscitation (CPR) is poor. We report on survival and early neurological outcomes of children with heart disease supported with rapid-response extracorporeal membrane oxygenation (ECMO) to aid cardiopulmonary resuscitation (ECPR).

Methods and Results—Children with heart disease supported with ECPR were identified from our ECMO database. Demographic, CPR, and ECMO details associated with mortality were evaluated using multivariable logistic regression. Pediatric overall performance category and pediatric cerebral performance category scores were assigned to ECPR survivors to assess neurological outcomes. There were 180 ECPR runs in 172 patients. Eighty-eight patients (51%) survived to discharge. Survival in patients who underwent ECPR after cardiac surgery (54%) did not differ from nonsurgical patients (46%). Survival did not vary by cardiac diagnosis and CPR duration did not differ between survivors and nonsurvivors. Factors associated with mortality included noncardiac structural or chromosomal abnormalities (OR, 3.2; 95% CI, 1.3–7.9), use of blood-primed ECMO circuit (OR, 7.1; 95% CI, 1.4–36), and arterial pH <7.00 after ECMO deployment (OR, 6.0; 95% CI, 2.1–17.4). Development of end-organ injury on ECMO and longer ECMO duration were associated with increased mortality. Of pediatric overall performance category/pediatric cerebral performance category scores assigned to survivors, 75% had scores 2, indicating no to mild neurological injury.

Conclusions—ECPR may promote survival in children with cardiac disease experiencing cardiac arrest unresponsive to conventional CPR with favorable early neurological outcomes. CPR duration was not associated with mortality, whereas patients with metabolic acidosis and noncardiac structural or chromosomal anomalies had higher mortality.

ICU: T3 therapy after congenital heart surgery

Circulation. 2010;122:S224-S233

Triiodothyronine Supplementation in Infants and Children Undergoing Cardiopulmonary Bypass (TRICC)
A Multicenter Placebo-Controlled Randomized Trial: Age Analysis

Michael A. Portman, MD; April Slee, MS; Aaron K. Olson, MD; Gordon Cohen, MD, PhD; Tom Karl, MD; Elizabeth Tong, PhD; Laura Hastings, MD; Hitendra Patel, MD; Olaf Reinhartz, MD; Antonio R. Mott, MD; Richard Mainwaring, MD; Justin Linam, MA; Sara Danzi, PhD, for the TRICC Investigators

Background—Triiodothyronine levels decrease in infants and children after cardiopulmonary bypass. We tested the primary hypothesis that triiodothyronine (T3) repletion is safe in this population and produces improvements in postoperative clinical outcome.

Methods and Results—The TRICC study was a prospective, multicenter, double-blind, randomized, placebo-controlled trial in children younger than 2 years old undergoing heart surgery with cardiopulmonary bypass. Enrollment was stratified by surgical diagnosis. Time to extubation (TTE) was the primary outcome. Patients received intravenous T3 as Triostat (n=98) or placebo (n=95), and data were analyzed using Cox proportional hazards. Overall, TTE was similar between groups. There were no differences in adverse event rates, including arrhythmia. Prespecified analyses showed a significant interaction between age and treatment (P=0.0012). For patients younger than 5 months, the hazard ratio (chance of extubation) for Triostat was 1.72. (P=0.0216). Placebo median TTE was 98 hours with 95% confidence interval (CI) of 71 to 142 compared to Triostat TTE at 55 hours with CI of 44 to 92. TTE shortening corresponded to a reduction in inotropic agent use and improvement in cardiac function. For children 5 months of age, or older, Triostat produced a significant delay in median TTE: 16 hours (CI, 7–22) for placebo and 20 hours (CI, 16–45) for Triostat and (hazard ratio, 0.60; P=0.0220).

Conclusions—T3 supplementation is safe. Analyses using age stratification indicate that T3 supplementation provides clinical advantages in patients younger than 5 months and no benefit for those older than 5 months.

Postop. Neonatal Nutrition

Nutrition in Clinical Practice 2009;24:242-9.

Nutrition Support After Neonatal Cardiac Surgery
Joyce L. Owens, RD,CD, CANS
Ndidiamaka Musa, MD
Medical College of Wisconsin, Pediatrics: Critical Care, Milwaukee, Wisconsin.

Abstract
Congenital heart disease is the most common birth defect in the United States, with an estimated frequency of approximately 12–14 of 1000 live births per year. Neonates with congenital heart disease often need palliative or corrective surgery requiring cardiopulmonary bypass during the first weeks of life. The neonate undergoing cardiopulmonary bypass surgery experiences a more profound metabolic response to stress than that seen in older children and adults undergoing surgery. However, compared with older children and adults, the neonate has less metabolic reserves and is extremely vulnerable to the negative metabolic impact induced by stress, which can lead to suboptimal wound healing and growth failure. There are complications associated with the metabolic derangements of neonatal surgery requiring cardiopulmonary bypass, including but not limited to acute renal failure, chylothorax, and neurological dysfunction. This article discusses the importance of nutrition and metabolic support for the neonate undergoing cardiopulmonary bypass and the immediate postoperative nutrition needs of such a patient. Also, this article uses a case study to examine the feeding methodology used at one particular institution after neonatal cardiac surgery. The purpose of the case study is to provide an illustration of the many factors and obstacles that clinicians often face in the provision and timing of nutrition support.

Delayed Sternal Closure

J Thorac Cardiovasc Surg 1997;113:886-893

DELAYED STERNAL CLOSURE AFTER CARDIAC OPERATIONS IN A PEDIATRIC POPULATION

S. Tabbutt, MD, PhD, B. W. Duncan, MD, D. McLaughlin, RN, D. L. Wessel, MD, R. A. Jonas, MD, P. C. Laussen, MB, BS

Objective: The purpose of this study was to assess morbidity and mortality associated with delayed sternal closure after pediatric cardiac operations. Methods: Hospital records were reviewed of all patients with an open sternum after a cardiac operation at Children's Hospital, Boston, from January 1992 to December 1995. Results: A total of 178 patients had delayed sternal closure with an overall mortality rate of 19%. The most common diagnosis of patients with delayed sternal closure was hypoplastic left heart syndrome (29%). Although myocardial distention or chest wall edema (n = 47) was a common indication to delay sternal closure, in many patients (n = 47) the sternum was left open electively to avoid postoperative cardiac or respiratory compromise. Successful sternal closure was achieved in 158 patients (89%) at a mean of 3.4 ± 1.8 days after opening. There were significant increases in left atrial pressure (7.7 ± 3.4 to 9.8 ± 4.1 mm Hg, p = 0.00001) and right atrial pressure (8 ± 3.2 to 10.1 ± 3.3 mm Hg, p = 0.00001) with sternal closure. There was a small but statistically significant drop in pH (7.44 ± 0.05 to 7.41 ± 0.08, p < 0.0001) during sternal closure. The peak inspiratory pressure, delivered breaths per minute, and fraction of inspired oxygen all significantly increased during sternal closure. Clinical evidence of surgical site infection occurred in 12 (6.7%) of the patients with delayed sternal closure; mediastinitis developed in 7 (3.9%) patients. Conclusions: Although delayed sternal closure after complex operations for congenital heart disease is often necessary in the operating room because of edema, unstable hemodynamic conditions, or bleeding, it can also be used electively to aid in hemodynamic and respiratory stability in the initial postoperative period. Our review supports a low morbidity associated with delayed sternal closure in a pediatric population.

Delayed Sternal Closure is life-saving:

Children - European Journal of Cardio-thoracic Surgery 2002;21(5):787-93

Adult - Annals of Thoracic and Cardiovascular Surgery 2002;8:220-3

Nursing Consideration in Delayed Sternal Closure in Children: Critical Care Nurse June 2010;30:50-61.

Decrease in rSO2 (cerebral & somatic) after Delayed Sternal Closure - JTCVS Apr 2010;139:894-900

Laryngopharyneal Dysfunction after Norwood

J Thorac Cardiovasc Surg. 2005 Nov;130(5):1293-301. Epub 2005 Oct 13.
Laryngopharyngeal dysfunction after the Norwood procedure.
Skinner ML, Halstead LA, Rubinstein CS, Atz AM, Andrews D, Bradley SM.
Evelyn Trammell Institute of Voice and Swallowing, Department of Otolaryngology-Head and Neck Surgery, Charleston, SC, USA.

Abstract

OBJECTIVE: We sought to evaluate the incidence and significance of recurrent laryngeal nerve and swallowing dysfunction after a Norwood procedure compared with that after biventricular aortic arch reconstruction.

METHODS: From April 2003 through December 2004, 36 neonates underwent a Norwood procedure; 33 of 36 had postoperative fiberoptic laryngoscopy and modified barium swallow. Study results were used to guide the transition from nasogastric tube to oral feeding and placement of gastrostomy tubes. During the same time period, 18 neonates underwent aortic arch reconstruction as part of a biventricular repair.

RESULTS: After a Norwood procedure, laryngoscopy showed left true vocal fold (cord) paralysis in 3 (9%) of 33 patients. The results of a modified barium swallow were abnormal in 16 (48%) of 33 patients, with aspiration in 8 (24%) of 33 patients. Of the 3 patients with vocal fold paralysis, 2 had a normal modified barium swallow result, and 1 had aspiration. Gastrostomy tubes were placed in 6 (18%) of 33 patients, all with an abnormal modified barium swallow result. Hospital stay was longer in patients with an abnormal modified barium swallow result: 34 +/- 13 versus 22 +/- 7 days (P < .01).

After biventricular repair with aortic arch reconstruction, left true vocal fold paralysis occurred in 4 (25%) of 16 patients; results of a modified barium swallow were abnormal in 10 (59%) of 17 patients, with aspiration in 6 (35%) of 17 patients (all nonsignificant vs patients undergoing the Norwood procedure). Follow-up laryngoscopy in 4 patients with vocal fold paralysis showed no change in 3 of 4 patients and improvement in 1 patient. Follow-up modified barium swallow showed resolution of aspiration in 11 (85%) of 13 patients.

Hospital survival was 32 (89%) of 36 patients for the Norwood procedure and 18 (100%) of 18 patients for biventricular repair. There has been 1 sudden death before second-stage palliation.

CONCLUSIONS: After a Norwood procedure, swallowing dysfunction occurs in 48% of patients, with aspiration in 24%, and results in increased length of hospital stay. Left recurrent laryngeal nerve injury, seen in 9% of patients, is an uncommon cause of swallowing dysfunction. Postoperative aspiration generally resolves over time, whereas vocal fold paralysis does not. Systematic evaluation of swallowing function allows appropriate tailoring of feeding regimens and might contribute to decreased hospital and interstage mortality.

PMID: 16256781 [PubMed - indexed for MEDLINE]

Inhaled nitric oxide after Glenn

J Thorac Cardiovasc Surg. 2005 Jan;129(1):217-9.
Inhaled nitric oxide does not improve systemic oxygenation after bidirectional superior cavopulmonary anastomosis.
Adatia I, Atz AM, Wessel DL.
Department of Cardiology, Children's Hospital, Harvard Medical School, Boston, MA, USA. iadatia@pedcard.ucsf.edu
PMID: 15632849 [PubMed - indexed for MEDLINE]