[Show abstract][Hide abstract] ABSTRACT: Background Patients with Duchenne Muscular Dystrophy (DMD) develop cardiac fibrosis and dilated cardiomyopathy. We described the frequency of significant Holter findings in DMD, the relationship between cardiac function and arrhythmia burden, and the impact of these findings on clinical management.
Methods and Results A retrospective review was done of patients with DMD who received a Holter from 2010 to 2014. Clinical and arrhythmic outcomes were analyzed. Patients were classified based on left ventricular ejection fraction (LVEF): ≥55%, 35% to 54% and <35%. Significant Holter findings included atrial tachycardia, ventricular tachycardia and atrial fibrillation/flutter. Logistic regression was used to assess predictors of significant Holter findings and change in care. The study included 442 Holters in 235 patients. Mean age was 14±4 years. Patients with cardiac dysfunction were older, and had increased late gadolinium enhancement and left ventricular dilation (P<0.01). There were 3 deaths (1%), all with normal function and none cardiac. Patients with LVEF <35% had more arrhythmias including nonsustained atrial tachycardia (P=0.01), frequent premature ventricular contractions, ventricular couplets/triplets, and nonsustained ventricular tachycardia (P<0.001) compared to the other groups. LVEF <35% (P<0.001) was the only predictor of clinically significant Holter finding. Four patients (40%) had change in medication in the LVEF <35% group compared to 9 (3%) in the ≥55% and 4 (4%) in the 35% to 54% groups (P<0.001).
Conclusions Sudden cardiac events are rare in DMD patients with an LVEF >35%. Significant Holter findings are rare in patients with DMD who have an LVEF >35%, and cardiac dysfunction appears to predict significant Holter findings. Holter monitoring is highest yield among DMD patients with cardiac dysfunction.
Preview · Article · Jan 2016 · Journal of the American Heart Association
[Show abstract][Hide abstract] ABSTRACT: Objective:
While late gadolinium enhancement (LGE) in paediatric patients with hypertrophic cardiomyopathy (HCM) is reported as similar to adults, the relationship between LGE and ECG findings in paediatric patients is unknown. We sought to evaluate the relationship between LGE on cardiac MRI and LV precordial voltage on ECG.
This was a retrospective analysis of paediatric patients with HCM aged 9-21 years with cardiac MRI and ECG completed within 60 days of each other. Demographic, MRI and ECG data were compared between patients with and without LGE. Maximal diastolic septal thickness, septal to free wall ratio and LGE presence were compared with LV precordial voltage (SV1, RV6 and SV1+RV6).
This study included 37 patients (33 male). Mean age was 15.8±2.8 years. Mean maximal LV diastolic septal thickness was 22.1±7.9 mm. Mean septal to free wall ratio was 2.4±1.6 mm. LGE was present in 18 patients, with 16 isolated to the ventricular septum. Comparing patients with and without LGE, there was no difference in age (p=0.2) or body surface area (p=0.9). However, the presence of LGE was associated with significantly increased septal thickness (p=0.03), yet decreased voltages in SV1 (p=0.005), RV6 (p=0.005) and SV1+RV6 (p=0.002) despite increased septal dimensions.
A significant inverse relationship exists between LGE presence and LV precordial voltage in this population. Unexpectedly low LV precordial voltages in patients with HCM may serve as a clinical surrogate marker for myocardial fibrosis and potential loss of viable myocardial tissue.
[Show abstract][Hide abstract] ABSTRACT: Congenital abnormalities of the coronary arteries in the absence of structural heart disease account for a small but interesting percentage of cardiac lesions in children. Their presentation may vary from incidental identification to aborted/sudden cardiac death. Patients with aborted sudden death episodes will require significant support if they develop extensive ischaemic myocardial injury. Ultimately, surgical repair should be carried out as soon as haemodynamic stability is attained and the neurological status is evaluated. The aims of this article were to provide a review of congenital abnormalities of the coronary arteries most commonly seen in children in the ICU as well as to review the current critical-care management thereof.
Full-text · Article · Dec 2015 · Cardiology in the Young
[Show abstract][Hide abstract] ABSTRACT: Background:
-Risk associated with short QT (SQT) interval has recently received recognition. European studies suggest a prevalence of 0.02%-0.1% in the adult population, but similar studies in pediatric patients are limited. We sought to determine the prevalence of SQT interval in a pediatric population and associated clinical characteristics and outcomes.
Methods and results:
-Retrospective review of an ECG database at a single pediatric institution. The database was queried for ECGs on patients ≤ 21 years with electronically measured QTc of 140-340ms. Patients with QTc of 140-340ms confirmed by a pediatric electrophysiologist were identified for chart review for associated clinical characteristics, symptoms, and outcome. Patients with and without symptoms were compared in an attempt to identify variables associated with outcome. The query included 272,504 ECGs on 99,380 unique patients. Forty-five patients (35 male, 76%) had QTc ≤ 340ms, for a prevalence of 0.05%. Median age was 15 years (IQR 2-17), median QT 330ms (IQR 280-360), and median QTc 323ms (IQR 313-332). Females had significantly shorter QTc compared to males (312ms vs 323ms, p = 0.03). Two deaths were noted in chart review - one from respiratory failure and the second of unknown etiology in a patient with dilated cardiomyopathy.
-Short QT interval was a rare finding in this pediatric population, with a prevalence of 0.05%. Male predominance was identified, although the median QT interval was significantly shorter in females. There appear to be no unifying clinical characteristics for this pediatric patient cohort with short QT interval.
No preview · Article · Sep 2015 · Circulation Arrhythmia and Electrophysiology
[Show abstract][Hide abstract] ABSTRACT: Sudden cardiac death in the young (SCDY) is the leading cause of death in young athletes during sport. Screening young athletes for high-risk cardiac defects is controversial. The purpose of this study was to assess the utility and feasibility of a comprehensive cardiac screening protocol in an adolescent population. Adolescent athletes were recruited from local schools and/or sports teams. Each subject underwent a history and/or physical examination, an electrocardiography (ECG), and a limited echocardiography (ECHO). The primary outcome measure was identification of cardiac abnormalities associated with an elevated risk for sudden death. We secondarily identified cardiac abnormalities not typically associated with a short-term risk of sudden death. A total of 659 adolescent athletes were evaluated; 64% men. Five subjects had cardiac findings associated with an elevated risk for sudden death: prolonged QTc >500 ms (n = 2) and type I Brugada pattern (n = 1), identified with ECG; dilated cardiomyopathy (n = 1) and significant aortic root dilation; and z-score = +5.5 (n = 1). History and physical examination alone identified 76 (11.5%) subjects with any cardiac findings. ECG identified 76 (11.5%) subjects in which a follow-up ECHO or cardiology visit was recommended. Left ventricular mass was normal by ECHO in all but 1 patient with LVH on ECG. ECHO identified 34 (5.1%) subjects in whom a follow-up ECHO or cardiology visit was recommended. In conclusion, physical examination alone was ineffective in identification of subjects at elevated risk for SCDY. Screening ECHO identified patients with underlying cardiac disease not associated with immediate risk for SCDY. Cost of comprehensive cardiac screening is high.
No preview · Article · Sep 2014 · The American Journal of Cardiology
[Show abstract][Hide abstract] ABSTRACT: Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency is the most common disorder of mitochondrial fatty acid oxidation. We report a term male infant who presented at 3 days of age with hypoglycemia, compensated metabolic acidosis, hypocalcemia, and prolonged QTc interval. Pregnancy was complicated by maternal premature atrial contractions and premature ventricular contractions. Prolongation of the QTc interval resolved after correction of metabolic derangements. The newborn screen was suggestive for MCAD deficiency, a diagnosis that was confirmed on genetic analysis that showed homozygosity for the disease-associated missense A985G mutation in the ACADM gene. This is the first report of acquired prolonged QTc in a neonate with MCAD deficiency, and it suggests that MCAD deficiency should be considered in the differential diagnoses of acute neonatal illnesses associated with electrocardiographic abnormality. We review the clinical presentation and diagnosis of MCAD deficiency in neonates.
[Show abstract][Hide abstract] ABSTRACT: Background
In attempts to detect diseases that may place adolescents at risk for sudden death, some have advocated for population-based screening. Controversy exists over electrocardiography (ECG) screening due to the lack of specificity, cost, and detrimental effects of false positive or extraneous outcomes.Objectives
Analyze the relationship between precordial lead voltage on ECG and left ventricle (LV) mass by echocardiogram in adolescent athletes.Methods
Retrospective cohort analysis of a prospectively obtained population of self-identified adolescent athletes during sports screening with ECG and echocardiogram. Correlation between ECG LV voltages (R wave in V6 [RV6] and S wave in lead V1 [SV1]) was compared to echocardiogram-based measurements of left ventricular mass. Potential effects on ECG voltages by body anthropometrics, including weight, body mass index (BMI), and body surface area were analyzed, and ECG voltages indexed to BMI were compared to LV mass indices to analyze for improved correlation.ResultsA total of 659 adolescents enrolled in this study (64% male). The mean age was 15.4 years (14–18). The correlations between LV mass and RV6, SV1, and RV6 + SV1 were all less than 0.20. The false positive rate for abnormal voltages was relatively high (5.5%) but improved if abnormal voltages in both RV6 and SV1 were mandated simultaneously (0%). Indexing ECG voltages to BMI significantly improved correlation to LV mass, though false positive findings were increased (12.9%).Conclusion
There is poor correlation between ECG precordial voltages and echocardiographic LV mass. This relationship is modified by BMI. This finding may contribute to the poor ECG screening characteristics.
No preview · Article · Apr 2014 · Pacing and Clinical Electrophysiology
[Show abstract][Hide abstract] ABSTRACT: The spectrum of cardiac arrhythmias in the pediatric intensive care unit (PICU) range from those which are immediately life threatening to rhythms with little or no hemodynamic consequence. When a cardiac arrhythmia is suspected or diagnosed in the PICU, the first step should not be to specifically diagnose the rhythm mechanism, but rather to determine the effects of the rhythm, some of which may have need for immediate intervention perhaps without a specific diagnosis. At the other end of the spectrum are rhythms which may initially appear to be benign, but may exert sub-clinical effects prior to resulting in hemodynamic collapse. Thus even rhythm abnormalities that do not initially appear to be of hemodynamic significance should be completely investigated. The Electrocardiogram (ECG) remains the primary modality for diagnosis of cardiac rhythm abnormalities. This Chapter will review the interpretation of ECGs, basic mechanisms and treatment of cardiac arrhythmias and special circumstances involving arrhythmias in the PICU.
No preview · Article · Jan 2014 · Pediatric Critical Care Medicine
[Show abstract][Hide abstract] ABSTRACT: Purpose: Sudden cardiac death in the young (SCDY) is the leading cause of death in young athletes during sport. Screening young athletes for cardiac defects that put at them at risk for SCDY is controversial. The purpose of this study was to assess the utility of a unique screening protocol, utilizing a limited echocardiogram, in identification of cardiac abnormalities and prevent SCDY.
Methods: We recruited adolescent athletes from local schools and sports teams using fliers sent to schools and athletic trainers. Subjects underwent a history and physical examination by a pediatrician or pediatric nurse practitioner, an electrocardiogram and a limited echocardiogram, both reviewed on site by a pediatric cardiologist. Providers completing each station of the study (history and physical examination, electrocardiogram, and echocardiogram) were blinded to the outcome of other stations. A separate pediatric cardiologist reviewed the results of all studies on-site and recommendations for follow up were made if needed. The primary outcome measure was the identification of cardiac abnormalities associated with a risk for sudden death. We evaluated the following: the number of subjects with cardiac concerns based on history and physical examination alone; the diagnostic utility added by the electrocardiogram; and the additional diagnostic benefit of the echocardiogram. We secondarily looked at the identification of cardiac abnormalities not typically associated with a short-term risk of sudden death.
Results: 659 adolescent athletes aged 13-18 years enrolled in this study; 64% male. Four patients had cardiac findings associated with a risk for sudden death: prolonged QTc>500 ms (n=2) and type I Brugada pattern (n=1) identified by electrocardiogram, and significant aortic root dilation with a z-score = +5.5 (n=1) identified by echocardiogram. History and physical examination alone identified 76 (12%) subjects in which cardiology referral was recommended by the pediatrician/nurse practictioner. The four patients with conditions associated with risk for sudden death had normal history and physical examination. Electrocardiogram identified 68 (10%) subjects for which a follow-up echocardiogram or cardiology visit was recommended by the reading cardiologist: including left ventricular hypertrophy (LVH) by voltage criteria (n=28), prolonged QTc greater than 460ms (n=14), and type I Brugada pattern (n=1). Left ventricular mass was normal by echocardiogram in all patients with LVH on EEG. Echocardiogram additionally identified the following: dilated aortic root (z-score = +2 to +2.5)(n=7), left ventricular non-compaction (n=5), and atrial septal defect (n=2).
Conclusion: History and physical examination alone was ineffective in identification of individuals at risk for SCDY. Screening electrocardiogram and echocardiogram identified different types of cardiac disease that may put an individual at risk for SCDY. The addition of a limited screening echocardiogram also identified patients with underlying cardiac disease that may not pose immediate risk for sudden death but do require cardiac follow-up.
[Show abstract][Hide abstract] ABSTRACT: "Purpose ": Syncope is common in older children and adolescents and is typically due to neurocardiogenic syncope. Pediatric patients with syncope have low health-related quality of life (HRQOL) scores. The purpose of this study was to examine the impact of comorbidities on HRQOL scores in patients presenting with the chief complaint of syncope to a pediatric Syncope Clinic.
"Methods ": A retrospective case series of patients seen in a tertiary care cardiac center Syncope Clinic with initial visits between 6/2010-4/2013 was performed. Patients were included if they were 8-18 years of age and completed the Pediatric Quality of Life Inventory (PedsQL) HRQOL tool at the time of clinic presentation. Comorbidities were documented on each patient. The Wilcoxon Rank Sum test was used to compare PedsQL scores (Total, Physical, Psychosocial, Emotional, Social, and School) between healthy pediatric historical controls, syncope patients with no other medical illnesses, and syncope patients with chronic comorbid conditions. To account for multiple comparisons a Bonferroni correction was applied and a p-value < 0.0027 was considered significant.
"Results ": 468 patients were included for analysis. The patients were predominantly Caucasian (91%) and female (66%) with a mean age 14.82.7 years. Referrals to the Syncope Clinic were by primary care physicians (61%), the emergency department (13%), neurology (9%), the patient themselves (6%) or other provider types (11%). These patients had experienced a median of 2 (1-10) syncopal events and were experiencing a median of 2 (0-7) presyncopal episodes per week at the time of their clinic visit. There were 214 patients (46%) with no other reported medical problems. 254(54%) of these patients reported having syncope and other medical problems. Of those with other medical problems, 144 (57%) reported having one or more chronic diagnoses commonly seen as comorbidities with syncope including migraine headaches (37%), anxiety (28%), depression (20%), chronic fatigue (11%) and fibromyalgia (4%). The mean PedsQL scores for patients presenting with syncope with no other medical illnesses (n=214) were significantly lower in all domains (p<0.001) except for the Social Subscale compared to healthy control patients. Syncope patients with other chronic comorbid diagnoses (migraine headaches, anxiety, depression, chronic fatigue or fibromyalgia) had lower PedsQL scores across all domains (p<0.001) when compared to healthy controls and when compared to syncope patients with no other medical illnesses. (Figure 1)
"Conclusion ": Pediatric syncope patients commonly have other comorbid conditions. While patients with syncope have lower than normal HRQOL scores, those with comorbid chronic conditions have even worse HRQOL. Because of common comorbid conditions in this population, and the negative effect on HRQOL, this group of patients would be best served by a multidisciplinary approach, rather than cared for by a single provider, regardless of subspecialty.
[Show abstract][Hide abstract] ABSTRACT: Traditional imaging for ablation of supraventricular tachycardia has been fluoroscopy, although 3-dimensional electroanatomic mapping (3D) has been demonstrated to reduce radiation exposure. This study compares a technique for the reduction of radiation, low-dose fluoroscopy (LD), with standard-dose fluoroscopy (SD) and 3D with SD (3D-SD). This was a single institutional retrospective cohort study. All patients undergoing initial ablation for atrioventricular reentrant tachycardia (AVRT) or atrioventricular nodal reentrant tachycardia (AVNRT) from 2009 to 2012 were reviewed and divided into 3 groups: (1) SD, (2) 3D (CARTO or NavX) with SD, or (3) LD. LD uses the same equipment as SD but includes customized changes to the manufacturer's lowest settings by decreasing the requested dose to the detector. Primary outcomes were fluoroscopy time and dose area product exposure. One hundred eighty-one patients were included. The median age was 15.0 years (3.3-20.8); 59% had AVRT, 35% had AVNRT, and 6% had both AVRT and AVNRT. LD decreased the dose area product (DAP) compared with SD (637.0 vs 960.1 cGy*cm(2), p = 0.01) with no difference in fluoroscopy time. 3D-SD decreased fluoroscopy time compared with SD (9.9 vs 18.3 minutes, p <0.001) with DAP of 570.1.0 versus 960.1 cGy*cm(2) (p = 0.16). LD and 3D-SD had comparable DAP (637.0 vs 570.1 cGy*cm(2), p = 0.67), even though LD had significantly longer fluoroscopy time (19.9 vs 9.9 minutes, p <0.001). In conclusion, LD during catheter ablation of AVRT and AVNRT significantly reduced the DAP compared with SD and had similar radiation exposure compared with 3D with SD.
No preview · Article · Apr 2013 · The American journal of cardiology
[Show abstract][Hide abstract] ABSTRACT: Accessory pathways with "high-risk" properties confer a small but potential risk of sudden cardiac death. Pediatric guidelines advocate for either risk stratification or ablation in patients with ventricular pre-excitation but do not advocate specific methodology. We sought to compare the cost of differing risk-stratification methodologies in pediatric patients with ventricular pre-excitation in this single institutional, retrospective cohort study of asymptomatic pediatric patients who underwent risk stratification for ventricular pre-excitation. Institutional methodology consisted of stratification using graded exercise testing (GXT) followed by esophageal testing in patients without loss of pre-excitation and ultimately ablation in high-risk patients or patients who became clinically symptomatic during follow-up. A decision analysis model was used to compare this methodology with hypothetical methodologies using different components of the stratification technique and an "ablate all" method. One hundred and two pediatric patients with asymptomatic ventricular pre-excitation underwent staged risk stratification; 73% of patients were deemed low risk and avoided ablation and the remaining 27% ultimately were successfully ablated. The use of esophageal testing was associated with a 23% (p ≤0.0001) reduction in cost compared with GXT stratification alone and a 48% (p ≤0.0001) reduction compared with the "ablate all" model. GXT as a lone stratification method was also associated with a 15% cost reduction (p ≤0.0001) compared with the "ablate all" method. In conclusion, risk stratification of pediatric patients with asymptomatic ventricular pre-excitation is associated with reduced cost. These outcomes of cost-effectiveness need to be combined with the risks and benefits associated with ablation and risk stratification.
No preview · Article · Apr 2013 · The American journal of cardiology
[Show abstract][Hide abstract] ABSTRACT: Patients with congenital heart disease (CHD) are at increased risk of cardiac arrhythmias. The utility of ambulatory (Holter) monitoring in predicting these arrhythmias remains unclear. We sought to evaluate the clinical utility and cost effectiveness of Holter monitoring in patients with CHD. A retrospective study of patients with CHD who had undergone Holter monitoring was performed. The Holter data from patients with tetralogy of Fallot (TOF), d-transposition of the great arteries (d-TGA) after an atrial switch operation, and patients with a single ventricle after Fontan palliation were reviewed. The Holter indication included evaluation of clinical symptoms or as a part of routine screening. The Holter results were deemed clinically significant if they resulted in a change in patient treatment. Sudden cardiac events included death or aborted sudden death and appropriate defibrillator therapies. A total of 589 Holter studies were performed in 189 patients (100 with TOF, 38 with d-TGA, and 51 with Fontan). The results of Holter monitoring performed for clinical symptoms had a low positive predictive value (0.08) for clinically significant changes in management. On routine monitoring, the sensitivity was low (0.40) but the negative predictive value was high (0.96) for future clinically significant arrhythmias. The frequency of clinically significant findings and associated cost-effectiveness improved with older patient age and Fontan and d-TGA CHD type. Nonsustained ventricular tachycardia was associated with sudden cardiac events in patients with TOF but not in those with d-TGA or Fontan palliation. In conclusion, Holter monitoring is generally inefficient for symptomatic evaluation; however, within specific age and CHD type subgroups, such as patients with repaired TOF >25 years old, it could be useful in clinical management and risk assessment as a part of routine care.
No preview · Article · Dec 2012 · The American journal of cardiology
[Show abstract][Hide abstract] ABSTRACT: Pallid breath-holding (PBH) is a childhood condition that presents with recurrent syncope. Although typically benign, severe cases can lead to asystole and anoxic seizures. Previous studies have advocated pacemaker placement to abbreviate symptoms. This was a retrospective study of patients treated with fluoxetine for PBH spells. Clinical response, side effects and avoidance of pacemaker implantation were reviewed in six patients (12-60 months) treated with fluoxetine for PBH. Patients were referred because of concern of arrhythmia and failed medical treatment strategies. Two patients had previously implanted loop recorders, 5 patients had documented episodes of asystole, and 2 patients had generalized seizures. Fluoxetine resulted in alleviation of syncope in 5 of 6 patients. Time to symptomatic improvement symptoms ranged from 2 days to 1 month (median, 2 weeks). Median duration of treatment with fluoxetine was 12 months (12-24 months). One patient demonstrated no improvement and had a pacemaker implanted. There were no reported side effects to fluoxetine. Fluoxetine can be used to treat childhood PBH spells and may obviate the need for permanent pacing in a significant subset of this population. Considering its safe side-effect profile it is a worthwhile first-line agent to treat this disorder.
[Show abstract][Hide abstract] ABSTRACT: Introduction:
Cardiac conduction system injury is a cause of postoperative cardiac morbidity following repair of congenital heart disease (CHD). The national occurrence of postoperative complete heart block (CHB) following surgical repair of CHD is unknown. We sought to describe the occurrence of and costs related to postoperative CHB following surgical repair of common forms of CHD using a large national database.
Methods and results:
Retrospective, observational analysis performed over a 10-year period (2000-2009) using the Kids' Inpatient Database (KID). Visits for patients ≤24 months of age were identified who underwent surgical repair of ventricular septal defects (VSD), atrioventricular canal defects (AVC), and tetralogy of Fallot (TOF). Patients were identified who were diagnosed with postoperative CHB, further identifying those requiring a new pacemaker placement during the same hospitalization. Costs associated with visits were calculated. There were 16,105 surgical visits: 7,146 VSD, 3,480 AVC, and 5,480 TOF. There was a decrease in postoperative mortality (P = 0.0001) with no significant change in postoperative CHB. Hospital stay and cost were higher with CHB and placement of a permanent pacemaker. Repair of AVC (OR 1.77; [1.32-2.38]) was associated with a higher rate of postoperative CHB. Length of hospital stay and total cost were significantly increased with the development of postoperative CHB and increased further with placement of a permanent pacemaker.
There has been little change over time in the frequency of postoperative CHB in patients undergoing repair of VSD, AVC, and TOF. Postoperative CHB results in major added cost to the healthcare system.
No preview · Article · Jun 2012 · Journal of Cardiovascular Electrophysiology