Brugada syndrome patients with mutations exhibit more conduction abnormalities on ECG and have higher risk for cardiac events.

Patients with VSA and lethal ventricular arrhythmia are a population at high risk for recurrence of cardiopulmonary arrest, and there is no reliable indicator for predicting recurrence of ventricular arrhythmia. Insertion of an ICD with medication for VSA is appropriate for this high-risk population.

Statistical AnalysisAll numeric data are presented as the means ± SD. Because of differences in the variables and limited sample numbers, statistic analysis was performed using Wilcoxon nonparametric analysis or chi-square analysis when necessary. A p-value less than 0.05 was considered significant. Circ J 2007; 71: 1606 -1609 (Received May 8, 2007 revised manuscript received June 14, 2007; accepted June 22, 2007 Background This study was performed to investigate the frequency and importance of supraventricular arrhythmia and sinus node (SN) dysfunction in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Methods and ResultsEight patients with CPVT (mean age: 16.8±8.1 years) underwent an electrophysiological study. SN recovery time (1,389±394 ms) was slightly prolonged, and 4 of 8 patients had abnormal values. Atrial flutter (AF) was induced by low-rate atrial pacing in 2 patients and by isoproterenol infusion in 1 patient. Atrial fibrillation (Af) was induced by isoproterenol infusion in 2 patients. One patient presented with Af during the follow-up period, and 2 of 4 patients with AF/Af presented with increased SN recovery time.Conclusions Patients with CPVT frequently have associated with SN dysfunction, and inducible atrial tachyarrhythmias, which indicate that the pathogenesis of CPVT is limited not only to the ventricular myocardium, but also to broad regions of the heart, including the SN and atrial muscle. (Circ J 2007; 71: 1606 -1609)

Mutations in the human cardiac Na + channel K K subunit gene (SCN5A) are responsible for Brugada syndrome, an idiopathic ventricular fibrillation (IVF) subgroup characterized by right bundle branch block and ST elevation on an electrocardiogram (ECG). However, the molecular basis of IVF in subgroups lacking these ECG findings has not been elucidated. We performed genetic screenings of Japanese IVF patients and found a novel SCN5A missense mutation (S1710L) in one symptomatic IVF patient that did not exhibit the typical Brugada ECG. Heterologously expressed S1710L channels showed marked acceleration in the current decay together with a large hyperpolarizing shift of steady-state inactivation and depolarizing shift of activation. These findings suggest that SCN5A is one of the responsible genes for IVF patients who do not show typical ECG manifestations of the Brugada syndrome. ß

Late potentials are a noninvasive risk stratifier in patients with Brugada syndrome. These results may support the idea that conduction disturbance per se is arrhythmogenic.

A 70-year-old woman was admitted to the hospital with chest discomfort after quarreling with her neighbors. Electrocardiography revealed ST-segment elevation in leads I, II, III, aVL, aVF, and V2 through V6. Coronary angiography demonstrated normal arteries, but left ventriculography showed apical akinesis and basal hyperkinesis. Takotsubo cardiomyopathy was diagnosed on the basis of these characteristic findings. The creatine kinase and creatine kinase-MB concentrations were elevated at admission and reached maximum levels 6 hours after admission. The plasma level of brain natriuretic peptide was 10.7 pg/mL (reference range, <18.4 pg/mL) on the first hospital day. ST-segment elevation in leads I, II, III, aVL, aVF, and V2 through V6 persisted at 72 hours after admission. On the third hospital day, sudden rupture of the left ventricle occurred, and despite extensive resuscitation efforts, the patient died. Takotsubo cardiomyopathy presents in a manner similar to that of acute myocardial infarction, but ventricular systolic function usually returns to normal within a few weeks. To our knowledge, this is the first reported case of fatal left ventricular rupture associated with takotsubo cardiomyopathy. We suggest that takotsubo cardiomyopathy may be a newly recognized cause of sudden cardiac death.

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.

No abstract