BrS Patients Research Articles

Acute Pancreatitis (AP) in Post-bariatric Surgery (BRS) Status: Analysis of National Trends, Complications, and Outcomes 2007-2011: ACG Obesity Award

Introduction: Rates of BRS are increasing, and post-BRS patients have a high incidence of gallstones for which biliary intervention (ERCP) can be difficult. There are no studies addressing rates and outcome of AP in patients with BRS. Methods: The Nationwide Inpatient Sample (2007-2011) was reviewed for all adult patients (≥18 years) with primary diagnosis of AP. All patients with history of BRS admitted with AP (BRS-AP) were identified. BRS patients with pregnancy were excluded. ICD-9-CM codes were used to identify patients with AP (577.0) and history of BRS (V45.86). Univariate analysis was performed for demographics, hospital factors, and etiologies of AP. A multivariate analysis correcting for variables with p<0.05 was utilized to compare outcomes of complications, mortality, length of stay (LOS), and total hospitalization charges. Results: There were 1,349,842 admissions for AP, and patients with BRS accounted for 1.07% (n=14,386) of all admissions. There was a significant increase in prevalence of BRS among patients admitted with AP (0.73% to 1.39% over 5 years; p<0.001; Cochran-Armitage test). Univariate analysis comparing BRS-AP to non-BRS AP revealed differences in demographics, hospital factors, and etiologies. BRS-AP was more frequently observed in women (82.5% vs. 47.5%; p<0.01), gallstone-related AP (24.8% vs. 22.4%; p<0.01), and in those with obesity (BMI >30 kg/m2, 37.5% vs. 9.8%; p<0.01), while non-BRS AP was more frequent with alcohol related etiology (20.9% vs. 17.1%; p<0.01). Due to post-BRS anatomical changes, BRS-AP patients underwent fewer ERCPs (4.2% vs 7.7%; p<0.01) albeit more cholecystectomies (14.1% vs. 11.9%; p<0.01). After adjusting for patient, hospital, and etiological factors, complications of AP inclusive of pseudocyst (5.8% vs 3.2%; OR 1.61; 95% CI 1.23, 2.08), respiratory failure (3.4% vs. 1.3%; OR 2.70; 95% CI 1.85, 3.85) and acute kidney failure (7.8% vs. 3.9%; OR 1.41; 95% CI 1.14, 1.72) were all associated with non-BRS AP. The mortality rate although lower for BRS-AP did not reach significance (0.22% vs 0.96%; OR 0.5; 95% CI 0.23, 1.16). However, adjusted LOS (4.4 vs. 6.3 days; p <0.01) and total hospital charges ($28,200 vs. $ 31,600; p<0.01) were significantly lower in BRS-AP patients. Conclusion: Gallstone-related AP was more common in patients with BRS. Although rates of admissions for BRS-AP are increasing and ERCP is challenging, these patients have shorter length of stay, lower hospital charges, and lower AP-related morbidities compared to non-BRS patients.

Phase- and Frequency-Domain Analysis of the Surface ECG Localizes Arrhythmogenic Sources of Ventricular Fibrillation in Humans

<h3>Background</h3> Ventricular fibrillation (VF) has been proposed to be maintained by localized high-frequency sources. We tested the hypothesis that combined spectral and nonlinear analyses of the standard ECG enables accurate localization of VF sources. <h3>Methods</h3> Six precordial ECG leads were used to record from 10 ischemic cardiomyopathy (IC) and 15 Brugada syndrome (BrS; type 1 ECG) patients during VF. Fourier and Hilbert transforms of ECG waveforms were used for frequency and phase analyses, respectively. <h3>Results</h3> Despite temporal variability, induced VF episodes recorded for 19.9 ± 8.6 seconds displayed long-lasting periods (7.8 ± 2.1 seconds [range 4.9–12.8 seconds]) of spectral power at a common frequency (shared frequency [SF]) in all leads (5.9 ± 0.8 Hz). In BrS patients, phase analysis of the SF showed a V₁–V₆ activation sequence as would be expected from waves originating at the base of the ventricles in patients displaying a type 1 ECG pattern (Friedman <i>P</i> <.001). Hilbert-based phase comparison confirmed that the V₁–V₆ sequence was the most stable over the whole VF duration. However, phase analysis of the SF in IC patients with anteroseptal (n = 4), apex (2), and lateral (4) myocardial infarction displayed activation at V₁–V₂, V₃–V₄, and V₅–V₆ as the earliest, respectively, consistent with an activation originating from the scar location (<i>P</i> <.01). The observed patterns correlated with the more stable sequence observed during Hilbert-based phase analysis (<i>P</i> <.05). Paired comparison showed that phase sequences were similar during monomorphic ventricular tachycardia and VF (Pearson coefficient 0.58, <i>P</i> <.001). Also, a dominant frequency gradient was observed between precordial leads corresponding to the scar region and the contralateral leads (5.86 ± 0.9 Hz vs 5.44 ± 1.1 Hz; paired <i>t</i>-test <i>P</i> = .011). <h3>Conclusions</h3> Early VF in BrS and IC patients is characterized by a steady sequence in the phase-frequency domain consistent with anatomic location of the arrhythmogenic substrate. These results are consistent with the prediction that VF is maintained by a small number of high-frequency sources that interact with the surrounding myocardium to generate fibrillatory conduction.

Rebuttal to EP testing predicts cardiac events in patients with Brugada syndrome

In the 1984 Circulation study, electrophysiologic study (EPS) was performed in 35 patients without heart disease or documented or suspected spontaneous ventricular arrhythmias: 3 (9%) of these ostensibly healthy individuals had inducible ventricular fibrillation (VF) and 16 more (45%) had inducible nonsustained polymorphic ventricular tachycardia (VT). Importantly, Brugada stimulated only the right ventricle apex (RVA); still, the inducibility rate of VF with two or three extrastimuli was 6%. It is reasonable to assume that adding a similar number of stimulation trials from the right ventricular outflow track (RVOT) (as commonly done for BrS patients) would double the rate of false-positive induction of VF in healthy controls to 12%. Other studies of the false-positive rate of VF inducibility show similar results. 1 In FINGER, the VF inducibility rate for the largest population of patients with asymptomatic BrS was 37%; yet only 3% of inducible patients developed spontaneous VF during up to 5 years of follow-up. The relatively high false-positive rate of VF induction (12%) and the low positive predictive value of EPS (3% in FINGER) preclude the use of EPS for clinical decision-making. Brugada also quotes a study by Gasparini mentioning zero inducibility among 25 controls; however, only 6 were studied with triple extrastimulation. 2. Brugada quotes a study by Giustetto et al 2 as additional proof that VF inducibility is a predictor of spontaneous arrhythmias. In this study, 2 a positive EPS correlated with outcome because patients with a history of syncope or cardiac arrest frequently had both a positive EPS and an adverse outcome. In fact, Giustetto et al reported 103 patients with asymptomatic BrS: 81 underwent EPS and 17 (21%) had inducible VF, but none had spontaneous arrhythmias. The only death among asymptomatic individuals (1% mortality rate for the asymptomatic group) had refused EPS.

Tpeak-Tend interval as a new risk factor for arrhythmic event in patient with Brugada syndrome

Objective To evaluate Tpeak-Tend(Tp-e) interval in surface standard ECG as a new risk factor for arrhythmic event in patient with Brugada syndrome. Methods 23 male patients with Brugada syndrome and 20 male patients with paroxysmal supraventricular tachycardia(PSVT) as the control group were investigated in this study. Tp-e interval in surface standard ECG was compared between BrS and PSVT patients. Results Tp-e interval in BrS patients was significantly longer than that in PSVT patients (109.57 ± 2.86 ms vs. 88.50 ± 3.08ms, P < 0.05). There was significant difference in Tp-e interval between 16 BrS patients with arrhythmic events (including syncope, clinical ventricular fibrillation [VF] and programmed electrical stimulation [PES]-induced VF) and 7 BrS patients without arrhythmic events and PSVT patients(118.12 ± 0.40ms vs. 90.00 ± 5.27ms, P < 0.05; 118.12 ± 0.40ms vs. 88.50 ± 3.08ms, P <0.05). However, Tp-e interval was similar in BrS patients without arrhythmic events and PSVT patients (90.00 ± 5.27ms vs. 88.50 ± 3.08ms, P > 0.05). Conclusion The prolongation of Tp-e interval could serve as a new noninvasive event predictor for arrhyth- mic events in patients with Brugada syndrome.