Familial History Of Sudden Death Research Articles

Abstract 14479: Compound Heterozygosity With Two Novel Mutations in MYBPC3 as a Cause of Severe and Early-Onset Hypertrophic Cardiomyopathy

Case presentation: A 8-year-old male was diagnosed with severe hypertrophic cardiomyopathy (HCM) after a cardiac arrest from which he was successfully defibrillated. Maximal wall thickness was 23 mm (z-score 6.36) on echocardiography. An implantable cardioverter defibrillator (ICD) was implanted and atenolol was started. After 4 ventricular fibrillation-terminating ICD shocks in the following 2 months, further treatment is under consideration. A genetic test identified the likely pathogenic intronic variant (c.1927+337G>T) in the MYBPC3 gene. An additional variant in the same gene (p.Arg817Gly), of uncertain significance but potentially relevant for the phenotype, was also found. His 10-year-old sister was also diagnosed with severe HCM, genetic test identified the two previously referred variants and ICD was also implanted. In the 4-year-old one sister, who is apparently healthy, only the likely pathogenic intronic variant (c.1927+337G>T) was found. Regarding their parents, both with no evidence of cardiomyopathy, c.1927+337G>T variant was identified in the father, while p.Arg817Gly was present in the mother. Discussion: This clinical case is noteworthy as an example of compound heterozygosity in which each parent donates one alternate allele, being these alleles located at different loci within the same gen, which emphasizes the importance of family genetic testing. The variant of uncertain significance p.Arg817Gly appears to be a disease modifier, causing the phenotype to be expressed early and severely in the presence of the probably pathogenic intronic variant c.1927+337G>T in MYBPC3. This deep intronic variant has not been described previously but was found in thirteen index cases referred for HCM and a history of familial sudden death at an early age, being overrepresented in the cohort of HCM in the north of Spain. Being a carrier of both these two novel variants appears to cause an extremely aggressive childhood-onset phenotype.

675 A rare case of tako-tsubo syndrome in a patient with hypertrophic cardiomyopathy

Abstract Aims We know that basal septal hypertrophy is a rare and unique anatomical finding associated with hypertrophic cardiomyopathy (HCM). Tako-Tsubo cardiomyopathy (TTC) is a transient left ventricular systolic dysfunction induced by high physical or emotional stress. Its occurrence with HCM is unusual. However, this presentation occurs more often with the classic asymmetrical septal hypertrophy compared with the apical variant. This case demonstrates that the coexistence of TTC with septal HCM in an elderly patient may lead to a severe haemodynamic instability picture. Methods and results A 81-year-old female presented to the emergency department (ED) complaining of dyspnoea and chest pain lasting for 1 day. She had hypertension and dyslipidemia associated with a familial history of sudden death. On physical exam, we found a severe hypotension (systolic blood pressure of 80 mmHg) associated with bilateral rales at chest auscultation. Cardiac auscultation revealed a harsh systolic murmur, best heard over the left sternal border. Heart rate was 60 b.p.m. in sinus rhythm. Labs were significant for HS-I troponin of 6.035 ng/L (NV: ≤ 12) and NT-proBNP of 7.640 pg/ml (NV: ≤1800). A 12-leads electrocardiogram (ECG) at admission revealed a STEMI-like ST segment elevation from V2 to V6 (Figure 1A). For this reason she was urgently taken to the cath-lab where she was found to have tortuous but normal coronary arteries. After coronary angiography, a trans-thoracic echocardiogram (TTE) revealed a pathological LV hypertrophy with a septal diastolic thickness of 19 mm, depressed LV ejection fraction (LVEF) due to a severe apical ballooning. At continuous wave (CW)-Doppler there was a dynamic obstruction across the LV outflow tract (LVOT), with a late peak velocity of 4.9 m/s and an estimated peak gradient of 98 mmHg. The gradient was increased by a systolic anterior motion (SAM) of anterior mitral leaflet causing a moderate mitral regurgitation (MR). All these findings were consistent with obstructive septal HCM associated with Takotsubo cardiomyopathy. After treatment with intravenous diuretics and metoprolol (5 + 5 mg i.v. bolus followed by oral dose of 100 mg daily), her clinical condition markedly improved. One week later, ECG demonstrated deeply inverted T waves on antero-lateral leads and QT prolongation (501 ms). Three weeks later, after a complete resolution of the LV apical dyskinesia, LVEF normalized. LVOT gradient decreased to 20 mmHg, with a dynamic increase to 70 mmHg during Valsalva manoeuvre. Conclusions It is well known that TTC may be complicated by a reversible LVOT obstruction by itself but the combination with obstructive HCM can lead to low cardiac output and acute heart failure. This combination has been found to be not common and the correct treatment of this unusual type of cardiogenic shock is still unclear. Careful initial evaluation and continuous monitoring must be warranted in such rare cases. Supportive care afterward with beta blockers, along with echocardiogram surveillance, are the mainstay of management. Cardiologists, intensivisits, and clinicians alike need to recognize and comprehend the pathophysiology behind this unique clinical manifestation so that they may adjust their management and treatment accordingly.

C56. Isolated Right Ventricular Non-Compaction Cardiomyopathy (IRVNC) in Adolescence: A Case Report

Abstract Background Non-compaction ventricular myocardium (NCVM) is a rare genetic cause of cardiomyopathy which mostly affects the left ventricle. A limited case of IRVNC was reported which render a limited knowledge for clinician. Case Summary A 16-y.o male presented to our emergency unit with recurrent syncope, chest discomfort, palpitation which exaggerated by strenuous exercise. There was no familial history of sudden death. On admission, BP of 102/64 mmHg and bradycardia of 49 bpm were remarkable. Electrocardiography revealed sinus arrhythmia, 49 bpm with early repolarization on precordial leads and LVH. Laboratory tests were in normal limits. Echocardiography revealed hyper-trabeculated RV with no LV-dysfunction. CMR was performed and showed normal LV dimension and function. Right atrium and RV were dilated with RV-dysfunction. RV trabeculae were indicative for IRVNC (NC/C ratio of 4.3). Holter ECG monitoring was done and remarkable for sinus arrhythmia without sinus pause nor ventricular arrhythmia. Anticoagulant was given for embolic prevention in the non-compacted area. ACEi, β-blockers, and diuretic were not given due to hypotension, bradycardia and no signs of congestion. The patient showed clinical improvement and discharged after 5 days of hospitalization. Discussions Recently, there has been no specific criteria and cut off for IRNVC. Earlier studies mentioned that ILVNC criteria could be used for diagnosing IRNVC, as we used in our case. In the future, it’s necessary to determine new cut off points dedicated for IRVNC. Furthermore, close follow-up is needed as complications such as arrhythmia, embolic events and heart failure might occurred.

C56. Isolated Right Ventricular Non-Compaction Cardiomyopathy (IRVNC) in Adolescence: A Case Report

Abstract Background Non-compaction ventricular myocardium (NCVM) is a rare genetic cause of cardiomyopathy which mostly affects the left ventricle. A limited case of IRVNC was reported which render a limited knowledge for clinician. Case Summary A 16-y.o male presented to our emergency unit with recurrent syncope, chest discomfort, palpitation which exaggerated by strenuous exercise. There was no familial history of sudden death. On admission, BP of 102/64 mmHg and bradycardia of 49 bpm were remarkable. Electrocardiography revealed sinus arrhythmia, 49 bpm with early repolarization on precordial leads and LVH. Laboratory tests were in normal limits. Echocardiography revealed hyper-trabeculated RV with no LV-dysfunction. CMR was performed and showed normal LV dimension and function. Right atrium and RV were dilated with RV-dysfunction. RV trabeculae were indicative for IRVNC (NC/C ratio of 4.3). Holter ECG monitoring was done and remarkable for sinus arrhythmia without sinus pause nor ventricular arrhythmia. Anticoagulant was given for embolic prevention in the non-compacted area. ACEi, β-blockers, and diuretic were not given due to hypotension, bradycardia and no signs of congestion. The patient showed clinical improvement and discharged after 5 days of hospitalization. Discussions Recently, there has been no specific criteria and cut off for IRNVC. Earlier studies mentioned that ILVNC criteria could be used for diagnosing IRNVC, as we used in our case. In the future, it’s necessary to determine new cut off points dedicated for IRVNC. Furthermore, close follow-up is needed as complications such as arrhythmia, embolic events and heart failure might occurred.

Syncope in Children and Adolescents

Summary In the pediatric age group, most cases of syncope represent benign, neutrally-mediated alterations in vasomotor tone. Due to the global cerebral hypoperfusion, syncope is defined as a transient loss of consciousness followed by spontaneous recovery and/or a state of presyncope, including dizziness, lightheadedness, pallor, diaphoresis and palpitations which may precede the loss of consciousness. These symptoms could be a sign of a life-threatening event in a small subset of patients, even though most causes of syncope in childhood are benign, and life-threatening causes of syncope generally have cardiac etiology. In all these cases, routine evaluation includes history, physical examination and a 12-lead standard electrocardiogram which should be performed. Further investigation is indicated by worrying features which include syncope that occurs without warning, syncope during exercise, history of familial sudden death, and abnormalities on clinical exam or electrocardiography. The fact is that syncope generates great fear of injury or sudden death among parents and doctors, and the main aim of the present paper is to help the physician involved in the care of children to differentiate the life-threatening causes of syncope from the common, more benign neutrally-mediated syncope.

心室細動発症を契機に診断された筋強直性ジストロフィーの1例(Manifestation of sudden–onset ventricular fibrillation along with myotonic dystrophy type 1: a case report)

要旨患者は43歳の女性。外出中に卒倒し救急要請された。救急隊接触時は心室細動による心停止状態であり，電気的除細動を含む心肺蘇生を実施しながら当院へ搬送となった。心室細動は持続しており，extracorporeal cardiopulmonary resuscitationを導入開始し，心停止から73分後に経皮的人工心肺補助装置を作動させた。入院後に集学的治療を施行し一命をとり留めた。心室細動の原因疾患を検索したが，心臓超音波検査や冠動脈造影検査を含む諸検査では器質的異常は認められず，また蘇生後に延長していたQTc時間は経時的に正常化した。一方で，患者は突然死の家族歴を有し，四肢の筋萎縮が目立つ痩身体型で，西洋斧様顔貌といった特徴的な身体所見を呈していた。筋強直性ジストロフィーを疑い，分子遺伝学的検査を施行した結果，1型筋強直性ジストロフィー（DM1）と確定診断された。今回の心室細動の原因はDM1に起因するものと推察された。若年者の心室細動症例では，その背景に遺伝性疾患が存在する可能性も考慮すべきである。逆に，遺伝性疾患を有する患者においては，突然死の原因となる致死性不整脈の発症リスクを評価し，予防的ペースメーカーまたは植込み型除細動器の植込みを考慮すべきである。

Risk stratification in Brugada syndrome: Clinical characteristics, electrocardiographic parameters, and auxiliary testing

Risk stratification in Brugada syndrome remains a clinical challenge because the event rate is low but the presenting symptom is often cardiac arrest (CA). We review the data on risk stratification. A history of CA or malignant syncope is a strong predictor of spontaneous ventricular fibrillation (VF), whereas the prognostic value of a history of familial sudden death and the presence of a SCN5A mutation are less well defined. On the electrocardiogram, the presence of spontaneous type I electrocardiogram increases the risk for VF in all studies, whereas the presence of fragmented QRS complexes and early repolarization correlates with increased risk in several studies. Signal-averaged techniques using late potentials and microscopic T-wave alternans show some promising results in small studies that need to be confirmed. The value of electrophysiologic studies for predicting spontaneous VF remains controversial, and this includes programmed stimulation protocols that avoid a third extrastimuli or stimulation from the right ventricular outflow. Risk prediction is particularly challenging in children and women.

THE BC INHERITED ARRHYTHMIA PROGRAM: A MULTIDISCIPLINARY APPROACH TO FAMILIES AT RISK FOR SUDDEN DEATH

INTRODUCTION: Inherited arrhythmia (IA) disorders predispose to syncope, sudden cardiac arrest (SCA) and sudden death. Establishing a diagnosis is critical to implementing treatment and enabling cascade screening of at risk family members. An expert, multidisciplinary approach to this patient population is a guideline-based recommendation. The BC Inherited Arrhythmia Program (BCIAP) combines the expertise of cardiology and medical genetics in a provincial, multi-site, family-centered program targeting at risk patients and family members. Launched in April 2013; 400 referrals were expected in the first year, with 38 multidisciplinary clinics planned. METHODS: The BCIAP assesses patients and first-degree relatives for IA, SCA, and history of familial sudden death. An adult electrophysiologist (EP), genetic counsellor and research nurse attend patient evaluations. Families with children under 18 attend clinics that also include a pediatric EP and nurse. Medical Geneticists provide indirect patient care and case review. Patients undergo clinical assessment, investigations, and genetic counselling. Consent to contact for research is sought for all; the majority of patients in the Vancouver clinic are approached for voluntary research registry participation and bio banking. RESULTS: In the BCIAP’s first year, 576 referrals were received. The most common indication was Long QT syndrome (23%), followed by a family history of sudden death (14%). In total, 209 (46%) of referrals were for a family history indication, and 61 (67% excluding outreach) of the families referred to the program stemmed from cascade screening. Thirty-six multidisciplinary clinics were held at the program’s two main sites, (Vancouver and Victoria); a pediatric EP attended 39%. Additionally, 8 intake and 9 outreach clinics were held in Vancouver and Northern BC respectively. At the program’s two main sites, 398 patients were seen during 343 patient visits; 142 (41%) were family visits. Of families seen, 59% underwent assessment by both adult and pediatric EPs. In patients with available data, 113/398 (28%) underwent genetic testing. Predictive familial mutation testing results are available for 37 patients; 46% tested negative and were discharged. In Vancouver, 317 patients were invited to enrol in research. Of these, 294 provided consent (93%) and are in one or more registry. CONCLUSION: The BCIAP surpassed its target referral numbers and clinics by 44%, emphasizing the need for the service in BC. The number of referrals received for a family history indication and families referred suggests that the BCIAP supports a multidisciplinary family based approach. The potential of research is accepted broadly by this patient population.

Brugada Syndrome: the QuéBec Experience

Risk stratification in patients with Brugada syndrome (BS) is still controversial. Most commonly accepted predictors of adverse outcome are clinical symptoms and spontaneous type 1 ECG, whereas induction at electrophysiological study (EPS) and familial history of sudden death (SD) are controversial. The aim of this study was to assess the incidence and risk factors of ventricular arrhythmic (VA) events in patients with BS in Québec, Canada.

Empiric Quinidine for Asymptomatic Brugada Syndrome—Preliminary Results of an International Registry

<h3>Background</h3> Common practice for asymptomatic Brugada syndrome (BrS) has included risk stratification with electrophysiologic studies (EPS) and defibrillator implantation when the latter are positive. However, several multicenter studies show that EPS has limited value for predicting spontaneous ventricular fibrillation. Therefore, in 2008 we started this Prospective International Registry. <h3>Methods</h3> Patients with a type 1 Brugada ECG, who have no arrhythmia-related symptoms and no heart disease, are included in the Registry. They receive quinidine therapy or no therapy depending on physician's/patient's preference. EPS are not recommended. <h3>Results</h3> In total, 132 patients from the Netherlands (51), Italy (41), Israel (20), Germany (13), and Japan (7) have been recruited; 93 (70%) are male. Age at presentation is 43 ± 12 (11–79) years. Symptoms include palpitations (20%), chest pain (10%) and vagal syncope (20%); 54 patients have a family history of BrS or sudden death before age 50. The reason for index ECG was medical screening in 41 (31%), cardiac symptoms in 34 (26%), noncardiac symptoms (eg, fever) in 18 (14%), and screening for familial history of sudden death or BrS in 39 (30%). The type 1 ECG pattern was spontaneous in 45 patients (including spontaneous on "high leads" in 7 and fever-induced in 8) and drug-induced in 87. Disease-causing mutations were found in 23% and genetic variants of unknown significance in 5%. Nineteen patients received empiric quinidine therapy. Of them, 4 had presented with syncope (believed to be vasovagal) and 4 were asymptomatic but had familial history of sudden death or BrS. Nine patients had a spontaneous type 1 ECG pattern. Five (26%) patients discontinued quinidine because of asymptomatic QT prolongation (2 patients), diarrhea, asymptomatic abnormal liver function tests, and patient's preference (1 patient each). Follow-up >4 months (1.8 ± 0.9 years) is available for 59 patients. The only serious adverse event was syncope (leading to defibrillator implantation) in 1 untreated patient. <h3>Conclusions</h3> In our Prospective Registry of asymptomatic patients with BrS, most physicians and patients opt for no therapy. Long-term quinidine therapy is well tolerated by 74%. The risk of an arrhythmic event proved to be low.

Microvolt T‐Wave Alternans in Short QT Syndrome

T-wave alternans (TWA) is an accepted marker of risk for malignant ventricular arrhythmias, for which prognosis value has been established in different populations. Short QT syndrome (SQTS) is a very rare primary electrical disease carrying the risk of ventricular fibrillation. TWA in SQTS has not been evaluated yet. Thirteen patients with SQTS (QT = 308 ± 16 ms, QTc = 329 ± 10 ms, heart rate = 69 ± 8 beats/min) underwent microvolt TWA measurement using spectral analysis. TWA testing was performed using Heartwave II (Cambridge Heart™, Inc., Bedford, MA, USA) during bicycle exercice and classified as negative, positive, or indeterminate according to the published standards for clinical interpretation. Twelve patients were male (mean age 23 ± 5 years). Five were asymptomatic, three presented with aborted sudden cardiac death, and five with unexplained syncope. Six patients belonged to two unrelated families, while familial cases of SQTS were present for two other patients. A familial history of sudden death (SD) was present for seven patients. Ventricular fibrillation was inducible in three patients. Four patients were implanted with an implantable cardioverter-defibrillator and one presented with polymorphic ventricular tachycardia during follow-up. TWA was negative in each but one patient (indeterminate). Maximal negative heart rate was 118 ± 12 beats/min. Patients with previous SD displayed significant shorter QT and higher resting heart rate compared to the remaining cases. TWA testing is negative in 12 of 13 SQTS patients, even in the symptomatic or inducible ones. Measurement of TWA using conventional protocol and criteria for risk stratification in SQTS seems therefore useless.

A case of hypertrophic cardiomyopathy with familial history of sudden death, suffered from ventricular fibrillation

A case of hypertrophic cardiomyopathy with familial history of sudden death, suffered from ventricular fibrillation

A case of hypertrophic cardiomyopathy with familial history of sudden death, suffered from ventricular fibrillation

A case of hypertrophic cardiomyopathy with familial history of sudden death, suffered from ventricular fibrillation

HEART's Original [症例] 濃厚な突然死の家族歴を有する無症候性Brugada症候群の1例

HEART's Original [症例] 濃厚な突然死の家族歴を有する無症候性Brugada症候群の1例

The occurrence of Brugada syndrome and isolated cardiac conductive disease in the same family could be due to a single SCN5A mutation or to the accidental association of both diseases

The distinct cardiac arrhythmia diseases, Brugada syndrome (BS) and isolated cardiac conduction disease (ICCD) are caused by heterozygous mutations in the SCN5A gene. Previous studies have demonstrated an intriguing association between ICCD and BS with the same mutation in the SCN5A gene. The proband of a multigenerational family presented BS and a familial history of sudden death. We performed clinical evaluations in family members including drug testing and screening for SCN5A mutations. Based on electrocardiogram features, we identified four individuals with BS, two with ICCD and one compatible with both. For five individuals, one with BS and ICCD, three with BS and one with ICCD, we characterized a heterozygous C- to T- mutation at position 4313 (P1438L) in the SCN5A gene. Expression studies of the P1438L mutation showed non-functional channels. The proband's father with the BS phenotype was not a carrier of the new SCN5A mutation. We report the case of a family with BS and/or ICCD and describe a novel mutation, the P1438L SCN5A mutation. In this family, the occurrence of BS and ICCD could be due to this single mutation but also to the accidental association of both diseases.

Cardiomiopatia hipertrófica: importância dos eventos arrítmicos em pacientes com risco de morte súbita

To evaluate, in patients with hypertrophic cardiomyopathy and risk for SCD who underwent implantable cardioverter-defibrillator (ICD) implantation: a- the occurrence of arrhythmic events; b- the occurrence of clinical events and their correlation with arrhythmic events; c- the occurrence of ICD shock therapy and clinical and functional correlations; d- clinical and functional predictors of prognosis. Twenty six patients with hypertrophic cardiomyopathy and risk factors for SCD undergoing ICD implantation from May, 2000 to January, 2004 (mean follow-up = 20 months) were studied. Fourteen patients (53.8%) were females and the mean age was 42.7 years. ICD was indicated for primary prevention of sudden cardiac death in 16 patients (61.5%), and for secondary prevention in 10 patients (38.5%). Twenty patients (76.9%) presented syncope prior to ICD implantation; half of them were related to ventricular fibrillation or sustained ventricular tachycardia, 15 (57.7%) had a history of familial sudden death, 12 patients (46.2%) had nonsustained ventricular tachycardia on the 24-hour Holter monitoring, and five (19.2%) had an interventricular septal thickness greater than 30 mm. Four shock therapies were recorded by the ICD in potentially lethal arrhythmias (three patients with sustained ventricular tachycardia and one patient with ventricular fibrillation) during the follow-up. One death occurred, probably due to a thromboembolic stroke. Four patients had recurrence of syncope with no arrhythmic event recorded by the ICD. The statistical analysis showed a significant difference in early ICD shock therapy in patients whose interventricular septal thickness was greater than 30 mm. 1- occurrence of arrhythmic events in 50% of the patients; most of them (62%) were ventricular tachycardia, whether sustained (31%) or nonsustained (31%); in the remaining patients paroxysmal supraventricular tachycardia was observed. 2- recurrent syncope in the minority of the patients (16%), however not associated with the presence of arrhythmic events. 3- the presence of an interventricular septal thickness greater than 30 mm in the echocardiogram was associated with early shock therapy (p = 0.003). 4- absence of clinical or functional predictors.

Noninvasive Risk Stratification of Subjects with a Brugada‐Type Electrocardiogram and No History of Cardiac Arrest

Recent studies suggest that the Brugada-type electrocardiogram (ECG) is much more prevalent than the manifest Brugada syndrome. Although invasive electrophysiologic investigations have been proposed as a risk stratifier, their value is controversial, and alternative noninvasive techniques may be preferred. We sought a noninvasive strategy to detect a high-risk group in a long-term follow-up study of subjects with a Brugada-type ECG, and no history of cardiac arrest. This study enrolled 124 consecutive subjects with a Brugada-type ECG. Prognostic indices included: age, sex, a family history of sudden death, syncopal episodes, a spontaneous coved-type ST-segment elevation, maximal magnitude of ST-segment elevation, a spontaneous change in ST segment, a mean QRS duration, maximal QT interval, QT dispersion, late potentials (LP) by signal-averaged ECG, and microvolt T-wave alternans. Of the 124 subjects, 20 consenting subjects had an implantable defibrillator before follow-up. During a 40 +/- 19-month follow-up, 12 subjects (9.7%) reached one of the endpoints (sudden death or ventricular tachyarrhythmia). Of the 12 risk indices, a family history of sudden death, syncopal episodes, a spontaneous coved-type ST-segment elevation, a spontaneous change in ST segment, and LP had significant values. In multivariate analysis, a spontaneous change in ST segment had the most significance (a relative hazard, 9.2; P = 0.036). Combined assessment of this index and other significant indices obtained higher positive predictive values (43-71%). A spontaneous change in ST segment is associated with the highest risk for subsequent events in subjects with a Brugada-type ECG. The presence of syncopal episodes, a history of familial sudden death, and/or LP may increase its value.

Syncopes d’origine cardiaque chez l’enfant

Syncope is a frequent problem in childhood; generally, it is an isolated event and the common causes are benign. However, in some circumstances, syncope can herald a potentially lethal problem, especially when occurring during exercise. Routine evaluation includes history, physical examination and a 12-lead standard ECG should be performed in all cases. Worrying features which should be an indication for further investigation include syncope during exercise, collapse in a swimming pool, history of familial sudden death, and abnormalities on clinical exam or ECG. Structural cardiac abnormalities that may cause syncope and sudden death include aortic stenosis, hypertrophic cardiomyopathy and coronary malformations. All children with unrepaired or repaired congenital heart disease who experienced a syncope should be referred to a specialist. Primary arrhythmias that are easily diagnosed on ECG are the long QT syndrome, complete atrio-ventricular block and Wolff-Parkinson-White syndrome; ST elevation in V1-V3 may reveal a Brugada syndrome. Another arrhythmia which is known to be potentially fatal if undiagnosed is the catecholaminergic ventricular tachycardia; the baseline ECG is normal but the arrhythmia is easily reproduced during exercise testing. Finally, vasovagal syncope is the most likely cause of syncope in the young and it usually easily recognized.

Management of hypertrophic cardiomyopathy in children.

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disease characterized by unexplained left ventricular hypertrophy, typically involving the interventricular septum. Hypertrophy may be present in infants, but commonly develops during childhood and adolescence. Management of children with HCM aims to provide symptomatic relief and prevention of sudden death, which is the primary cause of death. Unfortunately, no randomized comparative trials to date have assessed different treatment options in HCM. Medical treatment with negative inotropic agents (beta-adrenoceptor antagonists [beta-blockers], verapamil) is the first therapeutic choice in all symptomatic patients. Beta-blockers also appear to have prognostic merit in children. Surgical myectomy is effective in reducing symptoms in children with left ventricular (LV) obstruction who are unresponsive to medical treatment, although a repeat operation may be needed in a substantial proportion of patients due to relapse of LV obstruction. The recently introduced percutaneous septal ablation can also be regarded as a feasible alternative in this cohort. Technical limitations of both invasive therapeutic options should be carefully considered, preferably in experienced centers. Results of recent randomized trials indicate that dual chamber pacing, once considered a therapeutic option for patients with HCM, should only be used as treatment for conduction abnormalities. Regular clinical risk stratification for sudden death is of vital importance for the prevention of sudden death in young patients. Familial history of sudden death at a young age, LV hypertrophy >3 cm, unexplained syncope, nonsustained ventricular tachycardia in Holter monitoring, and abnormal blood pressure response during exercise are currently considered clinical risk factors for sudden death. Each factor has a low positive predictive accuracy, but patients having two or more of these risk factors are deemed as high risk. Secondary prevention of sudden death in patients successfully resuscitated from cardiac arrest and/or sustained ventricular tachycardia warrants treatment with an implantable cardioverter defibrillator (ICD). Primary prevention of sudden death in patients considered to be at high risk should aim at the management of obvious arrhythmogenic mechanisms (paroxysmal atrial fibrillation, sustained monomorphic ventricular tachycardia, conduction system disease, accessory pathway, myocardial ischemia), and the prevention and/or management of ventricular tachyarrhythmias with amiodarone and/or ICD implantation, respectively. The choice of treatment in children is greatly influenced by technical aspects, such as adverse effects of amiodarone, and ICD implantation difficulties or complications. Amiodarone could also be used as a bridge in children at high risk, until they reach adulthood, possibly achieving a lower risk status, or until their physical growth permits ICD implantation as long-term therapy.

Syndrome de Brugada isolé et asymptomatique. À propos d’une observation

The case report of a 32-year-old man with a Brugada syndrome is presented. He was asymptomatic and without familial history of sudden death or syncope. Diagnosis criteria for Brugada syndrome were 1- a pattern of right bundle branch block and ST-segment elevation in leads V1 and V2 on the ECG, 2- no cardiac structural anomalies. Symptomatic patients with this electrical anomaly are at high risk of sudden death and need an automatic implantable defibrillator. The outcome and the treatment of asymptomatic patients are a matter of debate and are discussed in this report.