Is this a philosophic issue? Do patients with drug-induced Brugada type ECG have poor prognosis? (Pro).
Brugada syndrome (BS) has an intermittent or concealed type, which can be unmasked by the sodium (Na(+))-channel-blocker challenge test. The appropriate risk stratification of patients with a drug-induced Brugada-type electrocardiographic (ECG), especially those without a history of syncope or aborted sudden cardiac death, remains unclear. The prognosis of patients with BS depends on the clinical type, cardiac arrest, syncope or if asymptomatic. The ratio of the asymptomatic group varies from 56.9% to 63.6% and, furthermore, their annual cardiac event rate is relatively lower at 0.24-3.6% compared with the cardiac arrest group. Patients with a drug-induced Brugada-type ECG have a poor prognosis if they had a history of ventricular fibrillation (VF) or aborted sudden cardiac death, because their risk becomes similar to that of patients with spontaneous Brugada-type ECG. They have the disturbance of the Na(+)-channel and the electrophysiologic substrate of VF, proven by the high inducibility of VF by stimulation test even in patients without spontaneous VF. Spontaneous VF will never occur if there is no VF substrate. Implantable cardioverter-defibrillators will certainly protect them, so patients with a drug-induced Brugada-type ECG, even without a history of VF or aborted sudden cardiac death, should be considered to have a poor prognosis.
Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Minami Kogushi, Ube, Japan. ashimizu@yamaguchi-u.ac.jp
Akihiko
A
Shimizu
D000200:Action Potentials; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000209:etiology; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000009:adverse effects; D006329:Heart Conduction System / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D026941:Sodium Channel Blockers / Q000009:adverse effects; D017180:Tachycardia, Ventricular / Q000209:etiology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology
D026941:Sodium Channel Blockers