Low risk for arrhythmic events in asymptomatic patients with drug-induced type 1 ECG. Do patients with drug-induced Brugada type ECG have poor prognosis? (Con)

Circ J. 2010 Nov;74(11):2464-73. doi: 10.1253/circj.cj-10-0878. Epub 2010 Oct 15.

Abstract

The type 1 ST-segment elevation is diagnostic for Brugada syndrome (BS) and its presence may sometimes be associated with a high risk of arrhythmic events. The type 1 ECG is also known to be unmasked by administration of sodium-channel blockers in equivocal or suspected cases of BS, and the drug-challenge test is frequently used in the diagnostic approach. In large cohort studies the spontaneous appearance of the type 1 ECG with symptoms of aborted sudden death or unexplained syncope are indicative of a poor prognosis for patients with BS compared with not having clinical symptoms. Therefore, the spontaneous type 1 ECG appears to represent an important predictive sign for cardiac events. It is unknown, however, whether or not the drug-induced type 1 ECG is as useful as the spontaneous type 1 for predicting cardiac events in asymptomatic subjects showing non-type 1 ECG. Review of the literature for large cohort studies indicates that there is a low incidence of arrhythmic events in asymptomatic patients with either the spontaneous or drug-induced type 1 ECG compared with symptomatic subjects, and the drug-induced type 1 ECG in asymptomatic patients does not add to an increase in arrhythmic risk. Therefore, drug testing to unmask the type 1 ECG in asymptomatic patients with a non-type 1 BS ECG does not have an additional value for risk stratification of cardiac events, although it might be useful in symptomatic patients showing only the non-type 1 ECG.

Publication types

  • Comment
  • Review

MeSH terms

  • Action Potentials
  • Arrhythmias, Cardiac / complications
  • Arrhythmias, Cardiac / diagnosis*
  • Arrhythmias, Cardiac / metabolism
  • Arrhythmias, Cardiac / physiopathology
  • Arrhythmias, Cardiac / therapy
  • Brugada Syndrome / complications
  • Brugada Syndrome / diagnosis*
  • Brugada Syndrome / metabolism
  • Brugada Syndrome / physiopathology
  • Brugada Syndrome / therapy
  • Death, Sudden, Cardiac / etiology
  • Defibrillators, Implantable
  • Electric Countershock / instrumentation
  • Electrocardiography*
  • Electrophysiologic Techniques, Cardiac* / adverse effects
  • Heart Conduction System / drug effects
  • Heart Conduction System / metabolism
  • Heart Conduction System / physiopathology*
  • Humans
  • Predictive Value of Tests
  • Prognosis
  • Risk Assessment
  • Risk Factors
  • Sodium Channel Blockers* / adverse effects
  • Tachycardia, Ventricular / etiology
  • Time Factors
  • Ventricular Fibrillation / etiology

Substances

  • Sodium Channel Blockers