What variables were associated with the inducibility of ventricular fibrillation during electrophysiologic stimulation test in patients without apparent organic heart disease?
ABSTRACT The purpose of our study was to determine what variables were associated with ventricular fibrillation (VF) induced during electrophysiological stimulation test in patients without apparent organic heart disease.
Our study evaluated 77 patients (51+/-15 years) who underwent electrophysiological stimulation test, signal averaging, and Na+ channel-blocker challenge test (pilsicainide test). The subjects were divided into two groups, the Brugada group and non-Brugada group. Further, the patients were divided into three subgroups on the base of symptoms (8, 7 symptomatic; 9, 13 syncope; 28, 12 asymptomatic group; in the Brugada and non-Brugada groups, respectively). Multivariate analyses evaluated the association between baseline clinical factors and the induction of VF.
The inducibility of VF was significantly (p<0.0001) higher in the Brugada group (n=33, 73%) than the non-Brugada group (n=4, 13%). The multivariate analysis demonstrated that symptoms (odds ratio (OR) 31.6; 95% confidence interval (CI): 2.3-430.6; p<0.01), type 1 electrocardiogram after pilsicainide test (OR 21.3; CI: 1.7-272.2; p<0.02), and syncope (OR 13.5; CI: 1.2-158.8; p<0.05) were strongly associated with the inducibility of VF, but not with family history, type 1 electrocardiogram in control, positive in late potential, maxDeltaST elevation (>==200microV) after pilsicainide test.
The symptoms, syncope, and type 1 electrocardiogram after pilsicainide test were independently associated with the electrophysiological substrate of VF in patients without apparent heart disease.
SourceAvailable from: Yuji Kasamaki[Show abstract] [Hide abstract]
ABSTRACT: Association between sudden cardiac arrest and early repolarization (QRS slurring in the inferolateral leads) has drawn recent attention. We retrospectively assessed the prevalence of electrocardiographic J waves in 19 men aged 46.5±13.7 years who, between 1979 and 2011, were resuscitated after cardiac arrest due to ventricular fibrillation. There was no structural heart disease in this group. The J wave is an elevation of the QRS-ST junction of at least 0.1mV from baseline in the inferior or lateral leads, manifested as QRS slurring or notching. Eleven patients (age, 37.3±13.9 years) showed J waves in the inferior leads (n=8) or in both the inferior and lateral leads (n=3). Brugada syndrome was diagnosed in 5 patients (age, 46.4±15.7 years). The QRS complex was normal in the remaining 3 patients (age, 44.3±9.5 years). Ventricular fibrillation was induced by programmed ventricular stimulation with up to 3 extrastimuli from the right ventricular apex or outflow tract in 7 of the 10 J-wave syndrome patients tested, in all 5 Brugada syndrome patients, and in all 3 patients with a normal electrocardiogram. There appears to be an increased prevalence of J-wave syndrome among patients with a history of idiopathic ventricular fibrillation.Journal of Cardiology 03/2012; 59(3):313-20. DOI:10.1016/j.jjcc.2012.01.018 · 2.57 Impact Factor
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ABSTRACT: Isoproterenol (ISP), a beta-adrenergic agonist, suppresses arrhythmic storm in patients with sporadic Brugada syndrome (BS). However, the influence of ISP and the beta-adrenergic antagonist propranolol (PRO) on the inducibility and frequency of ventricular fibrillation (VF) in BS patients remains unclear. Twenty-seven BS patients with induced VF>10s in a control state were enrolled. Electrophysiological stimulation (EPS) testing was performed during ISP and after PRO in selected patients. The inducibility and frequency of VF were compared. Dominant frequency (DF) was obtained by Fast Fourier transform from 4-s data (phase) and sequentially every 2s up to phase 5. ISP prevented induction of VF in 20 of 25 patients (80%). During ISP, 5 patients experienced induction of VF. ISP significantly influenced DF transition compared with the control state. DF gradually increased but was unchanged after the middle phase. PRO had no effect on incidence of induced VF in 5 patients; increased PRO induced VF in 5 (83.3%) of 6 patients who tested negative during ISP. After PRO, 10 patients experienced induction of VF. Thus, PRO significantly influenced DF transition. DF after PRO was higher than that in the corresponding phase in the control state. ISP suppressed induction of VF and the increase of DF with time. PRO aggravated VF and accelerated DF.Journal of Cardiology 03/2012; 60(1):47-54. DOI:10.1016/j.jjcc.2012.02.001 · 2.57 Impact Factor
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ABSTRACT: 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.Circulation Journal 10/2010; 74(11):2455-63. DOI:10.1253/circj.CJ-10-0747 · 3.69 Impact Factor