Ehud Chorin

Risk stratification in Brugada syndrome: Clinical characteristics, electrocardiographic parameters, and auxiliary testing

Risk stratification in Brugada syndrome remains a clinical challenge because the event rate is low but the presenting symptom is often cardiac arrest (CA). We review the data on risk stratification. A history of CA or malignant syncope is a strong predictor of spontaneous ventricular fibrillation (VF), whereas the prognostic value of a history of familial sudden death and the presence of a SCN5A mutation are less well defined. On the electrocardiogram, the presence of spontaneous type I electrocardiogram increases the risk for VF in all studies, whereas the presence of fragmented QRS complexes and early repolarization correlates with increased risk in several studies. Signal-averaged techniques using late potentials and microscopic T-wave alternans show some promising results in small studies that need to be confirmed. The value of electrophysiologic studies for predicting spontaneous VF remains controversial, and this includes programmed stimulation protocols that avoid a third extrastimuli or stimulation from the right ventricular outflow. Risk prediction is particularly challenging in children and women.

Impact of Diabetes Mellitus and Hemoglobin A1C on Outcome After Transcatheter Aortic Valve Implantation.

Surgical aortic valve replacement (SAVR) is associated with an increased mortality risk in elderly or high-risk patients. Transcatheter aortic valve implantation (TAVI) is an alternative to surgery in patients with symptomatic severe aortic stenosis who are inoperable or at high operative risk. The impact of diabetes mellitus (DM) on patients referred to TAVI merits further investigation. The aim of our study was to evaluate the clinical characteristics and the impact of DM status on the updated Valve Academic Research Consortium 2-defined outcomes of TAVI and to stratify patient outcomes according to their initial glycated hemoglobin (HbA1c) levels. We enrolled and stratified patients who underwent TAVI at our institution according to DM status. A total of 586 patients were enrolled: 348 (59%) without DM and 238 (41%) with DM. There were no significant differences in 30-day mortality patients with diabetes compared to patients without diabetes (3.3% vs 2.9%, p = 0.974). Insulin-treated DM was not associated with adverse outcome in comparison to orally treated DM. To delineate the prognostic power of HbA1C in these patients, the cohort was divided into 3 groups according to HbA1C levels (<5.7%, 5.7% to 6.49%, and ≥6.5%). Patients with HbA1C ≥6.5% were at increased risk for mortality during follow-up (hazard ratio 2.571, 95% confidence interval 1.077 to 6.136, p = 0.033) compared to patients with HbA1C <5.7%. In conclusion, unlike SAVR, DM is not associated with an increased mortality risk after TAVI, nor is it associated with increased complications rates. A more poorly controlled disease, as manifested by elevated HbA1c levels, may be associated with increased mortality during long-term follow-up.

Prevention of post procedural acute kidney injury in the catheterization laboratory in a real-world population.

BACKGROUND Radiologists and cardiologists have a remarkably different approach to the clinical importance and to the need for prophylactic treatment of contrast-induced acute kidney injury (CI-AKI). OBJECTIVES To evaluate the efficacy of forced diuresis with matched controlled hydration (FMH) in a real-world, high risk population. METHODS This is an investigator-driven, single-center, retrospective analysis of prospectively collected data. A total of 150 consecutive patients undergoing coronary angiography, angioplasty or TAVR who were treated with FMH were compared to a matched historical control cohort. RESULTS In the FMH treated patients, eGFR improved following the procedure from 37ml/min per 1.73m2 at baseline to 39ml/min per 1.73m2 (p<0.001); the net creatinine decreased from 1.85mg/dl to 1.78mg/dl (p<0.001). Among the matched control group, eGFR deteriorated from a baseline value of 36.7ml/min per 1.73m2 to 33.2ml/min per 1.73m2 post procedurally (p<0.001); the net creatinine increased from 1.88mg/dl to 2.14mg/dl (p<0.001). The incidence of post procedural AKI was substantially lower in the FMH treated group (2.7%) compared to the control group (26.7%). By multivariable analysis FMH treatment was independently correlated with reduced incidence of post procedural AKI compared with the control group (OR 0.06, p<0.001). Contrast volume did not correlate with AKI in neither univariate nor multivariate analyses. CONCLUSIONS In patients undergoing coronary angiography, angioplasty or TAVR, who are considered high risk to develop post procedural AKI, forced diuresis with matched controlled hydration resulted in a significant net creatinine decrease, eGFR increase and a decrease in the incidence of AKI.

Left atrial appendage and pulmonary artery anatomic relationship by cardiac-gated computed tomography: Implications for late pulmonary artery perforation by left atrial appendage closure devices

BACKGROUND Delayed pulmonary artery (PA) perforation and tamponade caused by implantable left atrial appendage (LAA) closure devices has been reported in patients with close proximity between these structures. The LAA and PA anatomic relationship (LAA-PAar) has not been analyzed systematically. OBJECTIVE The purpose of this study was to identify LAA-PAar variants potentially susceptible to this complication using cardiac-gated computed tomography angiography. METHODS We studied 100 consecutive patients with atrial fibrillation undergoing cardiac-gated computed tomography angiography of the left atrium. The LAA-PAar was classified into 3 types on the basis of the location, length, and thickness of the segment of contact between the PA and/or its branches and the LAA: type 1, no contact; type 2, contact involving the proximal LAA (defined as the proximal 15 mm extending into the LAA from its ostium, or the LAA proximal to the first major bend arising <15 mm from the ostium); and type 3, contact limited to the distal LAA. RESULTS LAA-PAar types 1, 2, and 3 were present in 7 (7%), 28 (28%), and 65 (65%) patients, respectively. For LAA-PAar type 2, the mean contact segment thickness and length were 0.6 ± 0.3 and 18.1 ± 10.6 mm, respectively. For LAA-PAar type 3, the distance between the LAA orifice and the segment of contact was <30 mm in 52 patients (80%). CONCLUSION In this series, the LAA came in direct contact with the main PA in the majority of patients. Contact involved the proximal LAA (where the fixation components of most LAA closure devices are positioned) in 28% of patients, posing potential vulnerability to PA perforation.

Long-term flecainide therapy in type 3 long QT syndrome

Aims Type 3 long QT syndrome (LQT3) is caused by gain-of-function mutations in the cardiac sodium channel gene (SCN5A). Previous reports on the long-term use of sodium channel blockers in LQT3 are sparse. The objective of the current study was to evaluate the long-term safety and efficacy of flecainide therapy in patients with LQT3 who carry the D1790G SCN5A mutation. Methods and results The study population comprised 30 D1790G carriers who were treated with flecainide and followed for 1-215 months (mean 145 ± 54 months, median 140 months). The mean baseline (off-drug) QTc was 522 ± 45 ms, and shortened to 469 ± 36 ms with flecainide therapy, a mean decrease of 53 ms [10.1%] (P < 0.01). A QTc longer than 500 ms was evident in 53% of carriers at baseline, and only in 13% on flecainide. All carriers while being compliant with flecainide therapy had no cardiac events during an average follow up of 83 ± 73 months. Twenty carriers stopped flecainide after an average follow up of 40 ± 42 months without symptoms. Six of them (30%) had cardiac events 1-11 months after stopping flecainide. Flecainide induced the appearance of Brugada pattern in six carriers (20%, 5 males), was stopped in three and was not associated with arrhythmia. Sinus-node dysfunction was evident in six carriers (20%) and was fully corrected by flecainide in three. Conclusions These data suggest that long-term flecainide therapy is relatively safe and effective among LQT3 patients who carry the D1790G SCN5A mutation.

Female gender as independent risk factor of torsades de pointes during acquired atrioventricular block

BACKGROUND Female gender increases the risk of torsades de pointes (TdP) in the long QT syndrome, and this increased risk is assumed to be due to their longer QT interval. OBJECTIVE The purpose of this study was to study the interplay between gender, duration of the QT interval, and risk of TdP during AV block. METHODS We studied 250 patients (48% women) with AV block. QT interval was measured at the time of most severe bradycardia. We then constructed different receiver operating characteristic curves for the QTc of males and females for predicting TdP. RESULTS As expected, patients with TdP had longer QTc intervals than did patients with uncomplicated AV block (564 ± 81 ms vs 422 ± 62 ms, P < .001). This correlation between longer QTc and higher risk of TdP was true for both genders. However, the QT of females with TdP was shorter than the respective value for males with TdP. Despite similar severity of bradycardia, the QT was shorter for females (QT 672 ± 88 ms vs 727 ± 57 ms for females with TdP vs males with TdP, P = .022). The QTc/TdP risk curve for females was shifted to the left in comparison to the pertinent graph for males. Female gender was an independent predictor of TdP. CONCLUSION Women are at increased risk for developing TdP during AV block, but this increased risk is independent of their longer QT interval. Females develop TdP with QT intervals that are not necessarily arrhythmogenic for males.

Radiofrequency Ablation of Atrial Fibrillation: Nonrandomized Comparison of Circular versus Point-by-Point “Smart” Ablation for Achieving Circumferential Pulmonary Vein Isolation and Curing Arrhythmic Symptoms

Pulmonary vein isolation (PVI) with radiofrequency (RF) ablation is now standard care for atrial fibrillation (AF). New improvements in PVI techniques include use of catheters that measure contact‐force and circular ablation catheters. These techniques have not been compared.

Electrocardiographic Manifestations of Calcium Abnormalities

The cardiac action potential is generated through voltage-gated ion channels allowing flow of ion currents through specific channels embedded in the cell membrane. Not surprisingly, abnormal serum electrolyte levels alter cardiac ion current kinetics. Depending on the alteration, changes in serum electrolyte concentrations affect cardiac conduction, alter the electrocardiogram (ECG), and can be arrhythmogenic or antiarrhythmic. Life-threatening arrhythmias are most commonly associated with potassium disorders, particularly hyperkalemia, and less commonly with disorders of serum calcium (Ca) and magnesium. In some cases, timely diagnosis of electrolyte abnormalities is crucial and emergency therapy for presumed life-threatening electrolyte disorders are often initiated, based on diagnostic ECG changes, even before laboratory results become available.1 In this issue of Annals of Noninvasive Electrocardiology, Sonoda et al.2 analyzed the effects of hypercalcemia on the ECG, focusing on its effects on J point elevation and arrhythmias. They compared the ECG of 89 patients with

Peripheral blood mononuclear cells of HIV-infected patients contain CD8 T cells that form conjugates with and kill HIV-infected autologous CD4 T cells

Peripheral blood mononuclear cells (PBMC) of untreated, HIV‐infected patients contain HIV‐specific CD8 T cells as well as their corresponding targets, HIV‐infected CD4 T cells. To determine if CD4 T‐cell depletion in HIV‐infected patients may result from autologous CD8–CD4 T‐cell interaction, CD8 and CD4 T cells procured from PBMC of acute and chronic untreated HIV‐infected patients were sorted and co‐incubated. Formation of CD8‐CD4 T‐cell conjugates was observed by fluorescence microscopy. Apoptosis of CD4 T cells in conjugation was recorded by digitized images and was further observed and measured by FACS using Annexin staining. Perforin expression in the CD8 T cells was measured using intracellular monoclonal perforin antibody staining. HIV DNA in the conjugated CD4 T cells was detected by in situ PCR. We found that 6·1 ± 0·5% of CD4 T cells from acute HIV‐infected patients and 3·0 ± 0·5% from chronic HIV‐infected patients formed CD8–CD4 T‐cell conjugates. Annexin binding and cell morphology typical of apoptosis were observed in the conjugated CD4 T cells. The majority of CD8 T cells that had conjugated to CD4 T cells expressed perforin. The conjugated CD4 T cells exhibited nuclear HIV DNA. CD8 T cells and HIV‐infected CD4 T cells, both procured from the PBMC of untreated HIV‐infected patients, form conjugates. Apoptotic lytic activity has been observed in the conjugated CD4 T cells. We propose that CD4 T‐cell annihilation in HIV‐infected patients results, at least in part, from the interactions of perforin‐rich CD8 T cells with autologous, HIV‐infected CD4 T cells.

Sex-based differences in prevalence and clinical presentation among pericarditis and myopericarditis patients

Background: Sex differences in heart diseases, including acute coronary syndrome, congestive heart failure, and atrial fibrillation, have been studied extensively. However, data are lacking regarding sex differences in pericarditis and myopericarditis patients. Objectives: The purpose of the study was to evaluate whether there are sex differences in pericarditis and myopericarditis patients as well. Methods: We performed a retrospective, single‐center observational study that included 200 consecutive patients hospitalized with idiopathic pericarditis or myopericarditis from January 2012 to April 2014. Patients were evaluated for sex differences in prevalence, clinical presentation, laboratory variables, and outcome. We excluded patients with a known cause for pericarditis. Results: Among 200 consecutive patients, 55 (27%) were female. Compared with men, women were significantly older (60 ± 19 years vs 46 ± 19 years, P < .001) and had a higher rate of chronic medical conditions. Myopericarditis was significantly more common among men (51% vs 25%, P = .001). Accordingly, men had significantly higher levels of peak troponin (6.8 ± 17 ng/mL vs 0.9 ± 2.6 ng/mL, P < .001), whereas women presented more frequently with pericardial effusion (68% vs 45%, P = .006). Interestingly, women had a significantly lower rate of hospitalization in the cardiology department (42% vs 63%, P = .015). Overall, there were no significant differences in ejection fraction, type of treatment, complications, or in‐hospital mortality. Conclusions: Most patients admitted with acute idiopathic pericarditis are male. In addition, men have a higher prevalence of myocardial involvement. Significant sex differences exist in laboratory variables and in hospital management; however, the outcome is similar and favorable in both sexes.