Appropriate and Inappropriate Implantable Cardioverter Defibrillators Therapies in Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia Patients.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited cardiomyopathy characterized histologically by the replacement of ventricular myocardium with fibrous and fatty tissue, and clinically by ventricular tachycardia arrhythmias primarily of right ventricular (RV) origin. Implantable cardioverter defibrillator (ICD) is the only proven therapy to reduce mortality in ARVC/D patients. However, it has the risk of inappropriate anti-tachycardia pacing (ATP) or shocks. This study aimed to assess the occurrence of appropriate and inappropriate ICD therapies in ARVC/D patients who underwent ICD implantation in a single Cardiac Centre. METHODS: Retrospective analysis of the data of patients with the diagnosis of ARVC/D based on the 2010 revised Task Force Criteria, who underwent ICD implantation in the Heart Centre, at King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh between January 1997 and May 2016. The clinical data and information about appropriate and inappropriate ICD therapies were obtained from medical records with the review of the available intra-cardiac electrograms (EGMs). RESULTS: Twenty-two ARVC/D patients with ICD implantation (20 males (91%), mean age at ICD implantation: 32 ± 14 years). ICD was implanted for secondary prevention of sudden cardiac death (SCD) in 15 patients (68.2%), and for primary prevention in 7 patients (31.8%). At mean follow-up of 9.4 ± 4.8 years, 11 patients (50%) had appropriate ICD therapies, and five patients (22.7%) had inappropriate ICD therapies. Out of 950 ICD therapies, 865 (91%) were appropriate (586 episodes of VT/VF treated with ATP (61.3%), and 279 episodes treated with shocks (29.37%)) and 85 (9.4%) were inappropriate (45 episodes treated with ATP (4.73%), and 40 treated with shocks (4.21%)). CONCLUSION: ARVC/D patients are at risk of VT/VF arrhythmias. ICD therapy is the only proven life-saving therapy in those patients. Most of ICD therapies in our patient's population are appropriate, and ATP therapy is effective in terminating most of VT episodes. Although we do not have any patient with subcutaneous ICD, the high success rate of ATP suggests that transvenous ICD would be more appropriate in ARVC/D patients.

Identification of novel genomic imbalances in Saudi patients with congenital heart disease.

BACKGROUND: Quick genetic diagnosis of a patient with congenital heart disease (CHD) is quite important for proper health care and management. Copy number variations (CNV), chromosomal imbalances and rearrangements have been frequently associated with CHD. Previously, due to limitations of microscope based standard karyotyping techniques copious CNVs and submicroscopic imbalances could not be detected in numerous CHD patients. The aim of our study is to identify cytogenetic abnormalities among the selected CHD cases (n = 17) of the cohort using high density oligo arrays. RESULTS: Our screening study indicated that six patients (~35%) have various cytogenetic abnormalities. Among the patients, only patient 2 had a duplication whereas the rest carried various deletions. The patients 1, 4 and 6 have only single large deletions throughout their genome; a 3.2 Mb deletion on chromosome 7, a 3.35 Mb deletion on chromosome 3, and a 2.78 Mb a deletion on chromosome 2, respectively. Patients 3 and 5 have two deletions on different chromosomes. Patient 3 has deletions on chromosome 2 (2q24.1; 249 kb) and 16 (16q22.2; 1.8 Mb). Patient 4 has a 3.35 Mb an interstitial deletion on chromosome 3 (3q13.2q13.31).Based on our search on the latest available literature, our study is the first inclusive array CGH evaluation on Saudi cohort of CHD patients. CONCLUSIONS: This study emphasizes the importance of the arrays in genetic diagnosis of CHD. Based on our results the high resolution arrays should be utilized as first-tier diagnostic tool in clinical care as suggested before by others. Moreover, previously evaluated negative CHD cases (based on standard karyotyping methods) should be re-examined by microarray based cytogenetic methods.

Clinical profile and mutation spectrum of long QT syndrome in Saudi Arabia: The impact of consanguinity.

BACKGROUND: Congenital long QT syndrome (LQTS) is an inherited, potentially fatal arrhythmogenic disorder. At least 16 genes have been implicated in LQTS; the yield of genetic analysis of 3 genes (KCNQ1, KCNH2, and SCN5A) is about 70%, with KCNQ1 mutations accounting for ∼50% of positive cases. LQTS is mostly inherited in an autosomal dominant pattern. Systemic analysis of LQTS has not been previously conducted in a population with a high degree of consanguinity. OBJECTIVES: To describe the clinical and molecular profiles of LQTS in the highly consanguineous Saudi population. METHODS: Fifty-six Saudi families with LQTS were consecutively recruited and evaluated. Sequencing of KCNQ1, KCNH2, and SCN5A genes was conducted on all probands, followed by screening of family relatives. RESULTS: Genetic analysis was positive in 32 (57.2%) families, with mutations in KCNQ1 identified in 28 families (50%). Surprisingly, 17 (53.1%) probands were segregating homozygous mutations. Family screening identified 123 individuals with mutations; 89 (72.4%) were heterozygous, 23 (18.7%) were homozygous, and 11 (8.9%) were compound heterozygous. Compared to heterozygous, the phenotype was more severe in homozygous individuals, with cardiac symptoms in 78.3% (vs 12.4%), family history of sudden death in 64.7% (vs 44.4%), and prolonged QT interval in 100% (vs 43.8%). Congenital deafness was found in 11 (47.8%) homozygous probands. CONCLUSION: Our study provides insight into the clinical and molecular profiles of LQTS in a consanguineous population. It underscores the importance of preemptive management in homozygous patients with LQTS and the value of clinical and molecular screening of at-risk relatives.

The Phenotype and Outcome of Infantile Cardiomyopathy Caused by a Homozygous ELAC2 Mutation.

OBJECTIVE: Cardiomyopathy (CMP) in children is a clinically and genetically heterogeneous group of disorders. Disease-associated mutations have been identified in more than 50 genes. Recently, mutations in the mitochondrial tRNA processing gene, ELAC2, were reported to be associated with the recessively inherited form of hypertrophic CMP (HCM). This study is aimed at describing the cardiac phenotype and outcome of ELAC2 mutation. METHODS: We performed whole exome sequencing followed by targeted mutation screening to identify the genetic etiology of severe infantile-onset CMP in 64 consanguineous Saudi families. RESULTS: A previously reported mutation (p.Phe154Leu) in ELAC2 gene was detected in 16 families. The index cases presented between 2 and 7 months of age with HCM in 13 infants and dilated CMP (DCM) in 3. Pericardial effusion was observed in 7 infants (44%). All infants died with a median age of death of 4 months. Almost 1/3 of them died during the initial presentation. CONCLUSION: Our study suggests screening the ELAC2 gene in severe infantile-onset HCM or DCM of unknown etiology, especially in the presence of pericardial effusion. Our work demonstrates a universally poor outcome of the (p.Phe154Leu) variant in ELAC2 gene; a correlation that helps in counseling parents and in planning appropriate medical intervention.

Gothic aortic arch and cardiac mechanics in young patients after arterial switch operation for d-transposition of the great arteries.

BACKGROUND: In patients who have undergone arterial switch operation (ASO) for d-transposition of the great arteries a gothic aortic arch (GA) morphology has been found and it has been associated with abnormal aortic bio-elastic properties. HYPOTHESIS: GA is frequent in ASO patients and may have an impact on cardiac mechanics. Our study aims were to assess 1- the occurrence of GA in a large sample of patients after ASO; 2- the association between GA and aortic bio-elastic properties; and 3- the impact of GA on left ventricular (LV) function using speckle tracking echocardiography (STE). METHODS: We studied one hundred and five asymptomatic patients, who have undergone first stage ASO for d-TGA, with normal left ventricular ejection fraction (LVEF ≥53%). RESULTS: Forty-six (44%) patients showed a GA (mean age 11.5±7.2years, 26 males) while fifty-nine (56%) patients (mean age 9.6±6.7years, 37 males) did not present GA. The two groups were comparable for age, sex, BSA, and office blood pressure values. In group GA aortic root was significantly dilated (27.4±7.5mm vs. 21.2±6.9mm, p<0.0001), aortic stiffness index (Group GA=1.8±1.2 vs. 1.4±0.7, p=0.025) was significantly increased, left atrial volume was larger (p=0.0145), global longitudinal strain (Group GA=-18.4±2.5% vs. -20.1±3.3%, p=0.012) and basal LV longitudinal strains (Group GA=-16.9±4.8% vs. -20.4±7.0%, p=0.013) were significantly reduced. CONCLUSIONS: After ASO the presence of a GA is associated with a significantly dilated aortic root, stiffer aortic wall, larger left atrial volume, and worse LV longitudinal systolic deformations, well known predictors of cardiovascular morbidity and mortality.

A substitution mutation in cardiac ubiquitin ligase, FBXO32, is associated with an autosomal recessive form of dilated cardiomyopathy.

BACKGROUND: Familial dilated cardiomyopathy (DCM) is genetically heterogeneous. Mutations in more than 40 genes have been identified in familial cases, mostly inherited in an autosomal dominant pattern. DCM due to recessive mutations is rarely observed. In consanguineous families, homozygosity mapping and whole exome sequencing (WES) can be utilized to identify the genetic defects in recessively inherited DCM. METHODS: In a consanguineous family with four affected siblings with severe DCM, we combined homozygosity mapping, linkage analysis and WES, to uncover the genetic defect. RESULTS: A region of homozygosity (ROH) on chromosome 8q24.13-24.23 was found to be shared by all of the four affected siblings. WES detected ~47,000 variants that were filtered to a homozygous mutation (p.Gly243Arg) in the FBXO32 gene, located within the identified ROH. The mutation segregated with the phenotype, replaced a highly-conserved amino acid, and was not detected in 1986 ethnically-matched chromosomes. FBXO32, which encodes a muscle-specific ubiquitin ligase, has been implicated in the pathogenesis of cardiomyopathy through the ubiquitin proteasome system (UPS). In addition, FBXO32-knockout mice manifest with cardiomyopathy. Screening the index patient for all of the WES variants in 48 genes known to be implicated in hypertrophic and dilated cardiomyopathy was negative. CONCLUSIONS: Our data suggest that FBXO32 is a candidate gene for recessive DCM. Acting as a cardiac ubiquitin ligase, mutated FBXO32 could perturb the degradation of target proteins in the UPS, the impairment of which has been observed in cardiomyopathy. Our work proposes that genes encoding other ubiquitin ligases could also be implicated in familial cardiomyopathy.

Left ventricular mechanics after arterial switch operation: a speckle-tracking echocardiography study.

BACKGROUND: The arterial switch operation (ASO) is nowadays the standard procedure for the repair of dextro-transposition of the great arteries (d-TGA). Reduced exercise capacity, coronary artery abnormalities, and reversible myocardial perfusion defects have been demonstrated in patients who have undergone ASO. Despite this, indices of systolic function, assessed by standard echocardiography, are within the normal range. Speckle-tracking echocardiography (STE) can detect early subclinical myocardial abnormalities in several diseases even in the presence of normal left ventricular (LV) ejection fraction. AIM: To assess LV systolic myocardial deformation and torsion in asymptomatic ASO patients with normal LV ejection fraction (≥55%) by using STE. METHODS: We studied 62 asymptomatic patients (26 women) who have undergone single-stage ASO for simple d-TGA, aged 8.5 ±â€Š5.7 years, with a normal LV ejection fraction (≥55%); 31 age and sex comparable controls (14 women), aged 7.9 ±â€Š4.9 years. RESULTS: In patients who have undergone ASO, global LV longitudinal strain was significantly lower than that in controls (-19.2 ±â€Š2.9% vs. -22.7 ±â€Š2.4%, respectively, P < 0.0001). Longitudinal deformation was significantly impaired in the anterior and both anterior and posterior septal walls. In patients who have undergone ASO global circumferential strain and LV torsion were similar to controls. At multivariate analysis global LV longitudinal strain was significantly correlated only with age at surgery (P = 0.005). CONCLUSION: We demonstrated a significant reduction in longitudinal myocardial deformation correlated with the age at surgical repair, despite a normal LV ejection fraction, in the largest series of asymptomatic ASO patients by using STE. Our findings suggest early (≤7 days) operation on d-TGA patients and continued monitoring of ventricular function by STE.

Hyperinsulinism in a child presenting with cardiac ischemia and bradycardia.

A 5-year-old boy referred to our service with suspected sinus node dysfunction. In addition to the arrhythmia, he had moderate mitral valve regurgitation and depressed ventricular function during a hypoglycemic episode. Cardiac abnormalities resolved with glucose infusion. We believe that hypoglycemia was responsible for the cardiac manifestations and it should be considered in unexplained rhythm disturbances or ischemia.

Near missed reversible cardiomyopathy: The value of the electrocardiogram.

Dilated cardiomyopathy is a devastating disease affecting the myocardium that is characterized by cardiac chamber dilatation with contractile function impairment in the absence of structural heart disease. The majority of cases are idiopathic; these patients have a poor outcome. However, identifying a reversible etiology and instituting appropriate intervention could reverse the disease process and result in complete recovery. An electrocardiogram is a simple, non-invasive and quick test that should be performed in each patient presenting with dilated cardiomyopathy. Failure to perform this test or misinterpreting its result could result in a tragic misdiagnosis of idiopathic cardiomyopathy, depriving the patient of a potentially curative intervention. Here, we report two cases of dilated cardiomyopathy caused by clinical conditions with recognizable ECGs. In both cases, the diagnosis was missed initially, delaying corrective interventions. These cases draw attention to the importance of performing and correctly interpreting ECGs in patients with dilated cardiomyopathy.

Outcomes of Damus-Kaye-Stansel anastomosis at time of cavopulmonary connection in single ventricle patients at risk of developing systemic ventricular outflow tract obstruction.

OBJECTIVES: Children with various single ventricle anomalies are at risk of developing systemic ventricular outflow tract obstruction (SVOTO) following volume unloading with cavopulmonary connection (CPC). We aim to evaluate the value of Damus-Kaye-Stansel (DKS) anastomosis at the time of CPC in eliminating late SVOTO risk. METHODS: Retrospective review of single ventricle patients who underwent DKS concurrent with CPC between 1997 and 2012 was performed. Clinical, echocardiographic and angiographic outcomes were analysed. RESULTS: Thirty-six children with single ventricle underwent DKS at the time of Glenn bidirectional CPC (n = 29) or Fontan total CPC (n = 7). The underlying anatomy was double inlet left ventricle (n = 18), double outlet right ventricle (n = 8), unbalanced atrioventricular septal defect (n = 4) and other (n = 6). Prior palliation included pulmonary artery band (n = 35), coarctation/arch repair (n = 11) and atrial septectomy (n = 8). Median age at the time of DKS was 8.9 months (range 3.6 months-9.1 years) and the median weight was 6.7 kg (range 5-27 kg). At the time of DKS, 17 patients (47%) had no SVOT gradient and 19 (53%) had SVOT gradient (mean 23.4 ± 18.7 mmHg). Overall survival was 89 and 83% at 1 month and 5 years, respectively. None of the deaths were related to SVOTO or DKS complications. When present, SVOT gradient decreased from 23.4 ± 18.7 mmHg preoperatively to 0 after DKS (P < 0.001). At the last follow-up, none of the patients developed any SVOT gradient; 78% of them had zero or trivial aortic/neoaortic valve regurgitation while 22% had mild regurgitation. None of the patients had evidence of compression of the left pulmonary artery or bronchus. Eighty-one percent of patients have reached or are suitable candidates awaiting final palliative surgery. CONCLUSIONS: DKS can be safely performed in conjunction with CPC without added mortality risk. It is very effective in mitigating SVOTO risk, with sustainable good semilunar valves function. Our data support an aggressive approach to performing DKS concurrent with CPC in children with single ventricle pathologies at risk of developing SVOTO.

Potential new indication for ivabradine: treatment of a patient with congenital junctional ectopic tachycardia.

Ivabradine is a new antiarrhythmic agent with direct inhibition of the pacemaker (If) current. It has been used extensively to decrease sinus rate in the treatment of cardiac failure, and also in a single case of atrial ectopic tachycardia in a child. Here we report the case of a 3-year-old girl with congenital junctional ectopic tachycardia (JET), resistant to conventional antiarrhythmic medications, who was successfully treated with ivabradine. We suggest that ivabradine can be an effective treatment for junctional automatic tachycardias and can be considered as a new line of therapy for this incessant form of tachycardia.

The phenotype of a CASQ2 mutation in a Saudi family with catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) manifests with episodic syncope or sudden death in young patients following physical activity or emotional stress. The autosomal recessive form of CPVT is caused by mutations in the CASQ2 gene. In a consanguineous family, a novel homozygous CASQ2 mutation (p.L77P) was identified in a child with CPVT who required implantation of a cardioverter defibrillator due to episodes of syncope while on medical therapy. Genetic testing found the younger sibling, who had normal initial clinical screening, to be affected. Our cases underscore the importance of family screening through genetic testing to preemptively apply the appropriate medical intervention in CPVT.

Recessively inherited severe aortic aneurysm caused by mutated EFEMP2.

Familial aortic aneurysm (AA) is mostly inherited as an autosomal dominant disorder. However, recessively inherited AA has also been observed but in association with skin manifestations of cutis laxa, which is caused by a mutated EFEMP2 gene. In the present study, we recruited 9 patients, from 4 unrelated consanguineous families, with recessively inherited AA. The index cases, their parents, and siblings underwent clinical evaluation and cardiac imaging. In the affected subjects, the clinical presentation ranged from sweating and cyanosis at 3 months of age to incidental findings in an asymptomatic adult. The echocardiogram revealed a wide spectrum of severity of the AA, with a Z-score varying from 5 to 33. Intrafamilial variability was also evident; 2 unrelated subjects were detected at 17 and 20 years of age through family screening. The skin manifestations of cutis laxa were not found in any patient. In 1 family, genome-wide single-nucleotide polymorphism analysis detected a homozygous block, shared by 2 affected siblings, on chromosome 11 at q13. Sequence analysis of EFEMP2, located on chromosome 11 at q13, identified a novel homozygous mutation (p.E161K) in all 9 affected subjects. In this largest cohort of reported patients with a mutated EFEMP2 gene, we illustrate the phenotypic spectrum of inherited AA due to a novel EFEMP2 mutation. In conclusion, our work suggests that in families with apparently recessively inherited AA, molecular analysis of EFEMP2 gene might be warranted.

Cardiac reoperations following the Ross procedure in children: spectrum of surgery and reoperation results.

OBJECTIVES: The Ross procedure is the preferred aortic valve replacement (AVR) choice in small children. Nonetheless, it is a complicated surgery and there are concerns that subsequent cardiac reoperations are exceptionally complex and associated with high morbidity and mortality. We examine the surgical spectrum and report outcomes of cardiac reoperations in patients who had undergone the Ross procedure during childhood. METHODS: Records of 227 consecutive children (<18 years old) who had undergone the Ross procedure at our institution from 1991 to 2004 were reviewed. Our patient cohort was 50 patients who underwent 58 cardiac reoperations following the Ross procedure during the follow-up. Time-related outcomes were analyzed. RESULTS: From 1992 to 2009, 50 patients, 37 males (74%), underwent cardiac reoperation at a mean age of 15.6±5.2 years and a mean interval of 3.9±3.0 years following the Ross procedure. Risk factors for cardiac reoperation following the Ross procedure on multivariable analysis were rheumatic fever, aortic regurgitation, concomitant cardiac surgery, use of fresh homografts and earlier era of surgery. Overall, 32 (55%) reoperations were isolated procedures whereas 26 (45%) were more complex involving 2-4 simultaneous cardiac procedures. In total, 92 procedures were performed including AVR (n=31), homograft replacement (n=23), mitral valve replacement (n=18), mitral valve repair (n=11), tricuspid valve repair (n=5) and other (n=4). There was no operative mortality and one late death. Survival was 98% at 10 years. During the follow-up, 8 of 50 patients required further cardiac surgery following initial reoperation with freedom from additional cardiac surgery of 82% at 10 years. Subsequent cardiac surgery risk was higher in patients with pre-operative aortic regurgitation and those who had concomitant surgery at time of Ross on log-rank analysis. Among survivors, 96% are in New York Heart Association class I/II. CONCLUSIONS: A wide range of cardiac reoperations may be required in children following the Ross procedure, especially those with underlying rheumatic aetiology, aortic regurgitation and multivalvular involvement. Despite complexity, reoperation following the Ross procedure can be performed with low mortality and good mid-term results. This information should be taken into consideration during the selection of aortic valve substitute in children.

Is the ross procedure a suitable choice for aortic valve replacement in children with rheumatic aortic valve disease?

BACKGROUND: Ross procedure is the aortic valve replacement of choice in children. Nonetheless, late autograft reoperation for dilatation and/or regurgitation is concerning. We examine whether Ross procedure is suitable in children with rheumatic fever. METHODS: Medical records of 104 children with rheumatic fever who underwent Ross procedure were reviewed (1991-2004). Competing risks methodology determined time-related prevalence and associated factors for two mutually exclusive end states: autograft reoperation and death prior to subsequent reoperation. RESULTS: Mean age was 13.8 ± 2.7, 83 (80%) were males. Hemodynamic dysfunction was primarily regurgitation (n = 92, 88%) and stenosis/mixed (n = 12, 12%). Competing risks analysis showed that in ten years after the Ross procedure, 1% of patients died, 32% underwent autograft reoperation, and 67% were alive and free from reoperation. Ten-year freedom from aortic regurgitation greater than or equal to moderate was 63%. Ten-year freedom from autograft reoperation was 65% for regurgitation versus 90% for stenosis/mixed disease. Risk factors for autograft reoperation were earlier surgery year (PE: 0.26 ± 0.06 per year; P < .001), additional surgery (PE: 0.82 ± 0.39, P = .04), no annular stabilization (PE: 1.21 ± 0.61, P = .05). Ten-year freedom from homograft replacement was 83%. Risk factors were fresh homografts (PE: 1.36 ± 0.71; P = .06) and aortic homografts (PE: 1.15 ± 0.59; P = .05). Ten-year freedom from any cardiac reoperation was 53%. Concomitant cardiac surgery was risk factor (PE: 1.37 ± 0.47; P = .004). CONCLUSIONS: Ross procedure in children with rheumatic fever is associated with excellent survival but results are plagued by aortic regurgitation and frequent autograft reoperation. Risk factors include preoperative regurgitation, concomitant surgery, dilated annulus, and earlier surgery era. Better patient selection in later era has mitigated autograft reoperation risk. Continued, improved candidate selection, along with modifications in autograft implantation and root/sinotubular stabilization techniques, may further decrease late autograft failure.

Hybrid management strategy for percutaneous Fontan completion without surgery: early results.

BACKGROUND: We report early results of surgical preparation and subsequent percutaneous Fontan completion strategy for the treatment of single-ventricle defects. METHODS: Two hundred twenty-seven patients underwent bidirectional cavopulmonary connection (BDCPC) between 2002 and 2007. Thirty-four patients had lateral tunnel created at time of BDCPC, fenestrated with 10 to 14 mm openings with the cardiac superior vena cava end patched to maintain BDCPC physiology. At second stage, Fontan circulation was established by superior vena cava patch perforation, tunnel dilatation, and stenting plus fenestration device closure. RESULTS: Thirty-four patients underwent Fontan preparation with BDCPC. Median age was 7.7 months (5 to 51) and 29 patients (85%) had previous palliation. Mean bypass and ischemic times were 141 and 72 minutes, respectively. Median ventilation, intensive care, and hospital stay durations were 1, 5, and 10 days, respectively. There was one early death and two take-downs. Twenty-eight patients underwent Fontan procedure: surgical (n = 3), percutaneous (n = 25). None of the patients who underwent percutaneous Fontan completion required inotropes, chest tube insertion, or mechanical ventilation. Median intensive care and hospital stay durations were 1 and 6 days, respectively. There were no early mortalities after percutaneous Fontan but one late death and one surgical revision. Overall survival after BDCPC with Fontan preparation was 77%. CONCLUSIONS: Despite longer bypass and ischemic times, Fontan preparation at time of BDCPC is feasible and associated with encouraging early outcomes. Percutaneous Fontan completion is associated with short recovery, low morbidity and excellent early dynamics, and echocardiographic and clinical outcomes. Further follow-up is needed to confirm those favorable results.

Who are the long-QT syndrome patients who receive an implantable cardioverter-defibrillator and what happens to them?: data from the European Long-QT Syndrome Implantable Cardioverter-Defibrillator (LQTS ICD) Registry.

BACKGROUND: A rapidly growing number of long-QT syndrome (LQTS) patients are being treated with an implantable cardioverter-defibrillator (ICD). ICDs may pose problems, especially in the young. We sought to determine the characteristics of the LQTS patients receiving an ICD, the indications, and the aftermath. METHODS AND RESULTS: The study population included 233 patients. Beginning in 2002, data were collected prospectively. Female patients (77%) and LQT3 patients (22% of genotype positive) were overrepresented; mean QTc was 516±65 milliseconds; mean age at implantation was 30±17 years; and genotype was known in 59% of patients. Unexpectedly, 9% of patients were asymptomatic before implantation. Asymptomatic patients, almost absent among LQT1 and LQT2 patients, represented 45% of LQT3 patients. Patients with cardiac symptoms made up 91% of all study participants, but only 44% had cardiac arrest before ICD implantation. In addition, 41% of patients received an ICD without having first been on LQTS therapy. During follow-up, 4.6±3.2 years, at least 1 appropriate shock was received by 28% of patients, and adverse events occurred in 25%. Appropriate ICD therapies were predicted by age <20 years at implantation, a QTc >500 milliseconds, prior cardiac arrest, and cardiac events despite therapy; within 7 years, appropriate shocks occurred in no patients with none of these factors and in 70% of those with all factors. CONCLUSIONS: Reflecting previous concepts, ICDs were implanted in some LQTS patients whose high risk now appears questionable. Refined criteria for implantation, reassessment of pros and cons, ICD reprogramming, and consideration for other existing therapeutic options are necessary.

Exteriorisation of the heart in two siblings.

We report two siblings with isolated ectopic hearts. Neither child had associated congenital diseases. To the best of our knowledge, this is the first reported familial occurrence of ectopic hearts.