Idiopathic Ventricular Fibrillation, Early Repolarization and Other J Wave-Related Ventricular Fibrillation Syndromes

Gi-Byoung Nam
2012 Circulation Journal  
Current clinical and experimental data demonstrate that the electrocardiographic J wave plays a critical role in the pathogenesis of ventricular fibrillation (VF) in patients with Brugada syndrome (BS) and early repolarization (ER) syndrome (ERS). This has generated renewed interest in the presence of J waves and ERS in the general population, yet the identification of high-risk ECG markers and the risk stratification of subjects with ERS remain to be established. More recently, this concept
more » ... ly, this concept has been expanded to VF mechanisms in patients with structural heart diseases. Some of the fatal arrhythmias in the setting of acute myocardial ischemia or infarction may share a similar, J wave-related electrophysiologic process. In canine arterially perfused wedge preparations, the occurrence of J waverelated arrhythmias is mediated by phase 2 reentry. The stability of the action potential (AP) dome in the ventricular epicardium is dependent on the prominence of the AP phase 1 notch. The ability to maintain the AP dome depends on a delicate balance between inward and outward ionic currents during depolarization and the early phase of repolarization. Outward shifts of the balance and inability to maintain the AP dome result in marked dispersion of repolarization and vulnerability to VF. This review describes the electrocardiographic and clinical features of the J waves in idiopathic VF and other structural heart diseases. (Circ J 2012; 76: 2723 - 2731 REVIEW Table. Risk Factors for Ventricular Arrhythmias in Long QT Syndrome and J Wave-Related Ventricular Fibrillation Syndromes Risk factors for torsades de pointes in LQTS (markers of reduced "repolarization reserve") Risk factors for polymorphic VT/VF in J-wave syndrome (markers of reduced "dome reserve") Female Male Congestive heart failure, acute ischemia Acute ischemia Hypokalemia, hypomagnesemia Hypocalcemia K channel blocker, psychotropic drugs, antibiotics, antifungals, antihistamine Na channel blocker, Ca channel blocker, K channel opener, psychotropic drugs, cocaine intoxication Fever Hypothermia (ERS), fever (some patients with BS) Bradycardia, pause Bradycardia, pause QT prolongation Prominent J wave
doi:10.1253/circj.cj-12-1306 pmid:23131759 fatcat:ur2sg6w6dzeeld5xdpkatw5tlm