ajmaline and Death--Sudden

We report on a youngster followed by his paediatrician from birth until 14 years of age for premature beats, most likely of ventricular origin. The sudden death of his sister provoked a re-assessment of his electrocardiograms (ECG), resulting in the diagnosis of Brugada syndrome and the subsequent implantation of a cardioverter defibrillator. This syndrome is a well known entity in adult cardiology, first described by Brugada and Brugada in 1992. It is considered to be the second most common cause of death in young adults after road traffic accidents. In children, however, the Brugada syndrome is not well known and we believe to be certainly underdiagnosed.

Topics: Adolescent; Adult; Ajmaline; Brugada Syndrome; Death, Sudden; Defibrillators, Implantable; Electrocardiography; Female; Humans; Male; Siblings; Sodium Channel Blockers; Tachycardia, Ventricular

The early repolarization (ER) pattern is associated with sudden death and has been shown to be heritable. Its significance when identified in families affected by sudden arrhythmic death syndrome (SADS) remains unclear.. We analyzed 12-lead ECGs of 401 first-degree relatives of individuals who had died from SADS. The prevalence of ER patterns was compared with family-clustered controls. ER was more common in SADS family members than in controls (21% versus 8%; odds ratio: 5.14; 95% confidence interval, 3.37-7.84) independent of the presence of a familial cardiac diagnosis. Both ascending and horizontal ER patterns were more common. In addition, ER was investigated for associations with findings from ajmaline provocation (n=332), exercise ECG (n=304), and signal-averaged ECG (n=118) when performed. ER was associated with a trend toward late depolarization, in general was suppressed with exercise and was unaffected by ajmaline. Inferior and horizontal patterns were, however, more likely to persist during exercise. Augmentation of ER with ajmaline was rare.. The ER pattern is more common in SADS family members than controls adjusted in particular for relatedness. The increased prevalence is irrespective of ER subtype and the presence of other inherited arrhythmia syndromes. ER may therefore represent an underlying heritable arrhythmia syndrome or risk factor for sudden death in the context of other cardiac pathology. The differing response of ER subtypes to exercise and ajmaline provocation suggests underlying mechanisms of both abnormal repolarization and depolarization.

Topics: Adult; Ajmaline; Arrhythmias, Cardiac; Case-Control Studies; Death, Sudden; Death, Sudden, Cardiac; Electrocardiography; Female; Humans; Male; Prevalence; Risk Factors

Brugada syndrome is characterized by sudden death secondary to malignant arrhythmias and the presence of ST segment elevation in leads V(1) to V(3) of patients with structurally normal hearts. This ECG pattern often is concealed but can be unmasked using potent sodium channel blockers. Like congenital long QT syndrome type 3 (LQT3) and sudden unexpected death syndrome, Brugada syndrome has been linked to mutations in SCN5A.. We screened a large European family with Brugada syndrome. Three members (two female) had suffered malignant ventricular arrhythmias. Ten members showed an ECG pattern characteristic of Brugada syndrome at baseline, and eight showed the pattern only after administration of ajmaline (total 12 female). Haplotype analysis revealed that all individuals with positive ECG at baseline shared the SCN5A locus. Sequencing of SCN5A identified a missense mutation, R367H, previously associated with sudden unexpected death syndrome. Two of the eight individuals who displayed a positive ECG after the administration of ajmaline, but not before, did not have the R367H mutation, and sequencing analysis failed to identify any other mutation in SCN5A. The R367H mutation failed to generate any current when heterologously expressed in HEK cells.. Our results support the hypothesis that (1) sudden unexpected death syndrome and Brugada syndrome are the same disease; (2) male predominance of the phenotype observed in sudden unexpected death syndrome does not apply to this family, suggesting that factors other than the specific mutation determine the gender distinction; and (3) ajmaline may provide false-positive results. These findings have broad implications relative to the diagnosis and risk stratification of family members of patients with the Brugada syndrome.

Topics: Adult; Ajmaline; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Bundle-Branch Block; Comorbidity; Death, Sudden; Electrocardiography; Female; Genetic Predisposition to Disease; Humans; Male; Mutation, Missense; NAV1.5 Voltage-Gated Sodium Channel; Pedigree; Phenotype; Sex Distribution; Sodium Channels; Spain; Syndrome

Topics: Ajmaline; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Bundle-Branch Block; Comorbidity; Death, Sudden; Electrocardiography; Genetic Predisposition to Disease; Mutation, Missense; NAV1.5 Voltage-Gated Sodium Channel; Pedigree; Phenotype; Sex Distribution; Sodium Channels; Spain; Syndrome

Cardiac arrhythmia causing sudden cardiac death is a serious worldwide public health problem. Antiarrhythmic agents have been available for therapy, but the conventional agents cause a high degree of intolerable side effects. The recent development of many new experimental antiarrhythmic agents has increased our capacity to effectively treat cardiac arrhythmias. Using a multifaceted approach of programmed electrical stimulation studies, drug level determinations, exercise testing and 24-hour ambulatory Holter monitoring, it can reasonably be decided which patient needs therapy and if therapy is going to be effective. Both aspects of the sudden death equation, ectopy frequency (triggering mechanism) and the ability to propagate sustained ventricular tachycardia (substrate), may be examined. Careful follow-up is needed to determine continued drug efficacy and the presence of side effects that may compromise patient compliance with therapy. If side effects intervene that may cause continued therapy to be intolerable, changing the antiarrhythmic agent, as opposed to decreasing the dosage to an ineffective range, may be appropriate. A comprehensive approach to arrhythmia management may begin to reduce the high incidence of sudden death due to fatal arrhythmias.

Topics: Adrenergic beta-Antagonists; Ajmaline; Amiodarone; Anilides; Anti-Arrhythmia Agents; Aprindine; Benzeneacetamides; Bepridil; Bethanidine; Bretylium Tosylate; Death, Sudden; Disopyramide; Encainide; Flecainide; Humans; Lidocaine; Mexiletine; Moricizine; Phenothiazines; Piperidines; Procainamide; Propafenone; Propiophenones; Pyrrolidines; Quinidine; Tachycardia; Tocainide; Verapamil