Shen, Win‐Kuang

Background Brugada syndrome is an inherited cardiac channelopathy associated with major arrhythmic events (MAEs). The presence of a positive family history of sudden cardiac death (SCD) as a risk predictor of MAE remains controversial. We aimed to examine the association between family history of SCD and MAEs stratified by age of SCD with a systematic review and meta‐analysis. Methods and Results We searched the databases of MEDLINE and EMBASE from January 1992 to January 2020. Data from each study were combined using the random‐effects model. Fitted metaregression was performed to evaluate the association between the age of SCD in families and the risk of MAE. Twenty‐two studies from 2004 to 2019 were included in this meta‐analysis involving 3386 patients with Brugada syndrome. The overall family history of SCD was not associated with increased risk of MAE in Brugada syndrome (pooled odds ratio [OR], 1.11; 95% CI, 0.82–1.51; P =0.489, I 2 =45.0%). However, a history of SCD in family members of age younger than 40 years of age did increase the risk of MAE by ≈2‐fold (pooled OR, 2.03; 95% CI, 1.11–3.73; P =0.022, I 2 =0.0%). When stratified by the age of cut point at 50, 45, 40, and 35 years old, a history of SCD in younger family member was significantly associated with a higher risk of MAE (pooled OR, 0.49, 1.30, 1.51, and 2.97, respectively; P =0.046). Conclusions A history of SCD among family members of age younger than 40 years was associated with a higher risk of MAE.

AbstractBackgroundThe subcutaneous implantable cardioverter‐defibrillator (S‐ICD) has a larger generator and its implantation involves more dissection and tunneling compared to traditional transvenous defibrillator system. Liposomal bupivacaine, an extended‐release bupivacaine with 72 h of duration has been used for postoperative pain management in patients undergoing S‐ICD implantation. Our aim was to compare postoperative pain and opioid prescription patterns among patients undergoing S‐ICD implantation who received intraprocedural liposomal bupivacaine and those who did not.MethodsWe performed a retrospective analysis of all patients who underwent subcutaneous ICD implantation from January 1, 2013 to March 30, 2018 at the Mayo Clinic in Rochester, Minnesota. Patients were categorized into those who received liposomal bupivacaine and those who did not. Data on inpatient pain score, outpatient opioid prescription rates at discharge, and doses based on oral morphine equivalents (OME) were collected.ResultsA total of 104 patients underwent S‐ICD implantation. Intraprocedural liposomal bupivacaine was used in 69% of patients. Patients who received intraprocedural liposomal bupivacaine had similar mean inpatient pain scores (2.9 vs. 2.9, p = .786). There was also no difference in the rate of inpatient opioid administration (79.2% vs. 87.5%, p = .4139), outpatient opioid prescription (23.6% vs. 12.5%, p = .29), or mean OME (41.7‐mg vs. 16.6‐mg, p = .188) when comparing patients those who received intraprocedural liposomal bupivacaine and those who did not.ConclusionIntraprocedural liposomal bupivacaine administration was not associated with any significant impact on postoperative pain scores, inpatient opioid administration, and outpatient opioid prescription rates or OME amounts at discharge.

AbstractBackgroundInappropriate sinus tachycardia (IST) remains a clinical challenge because patients often are highly symptomatic and not responsive to medical therapy.ObjectiveTo study the safety and efficacy of stellate ganglion (SG) block and cardiac sympathetic denervation (CSD) in patients with IST.MethodsTwelve consecutive patients who had drug‐refractory IST (10 women) were studied. According to a prospectively initiated protocol, five patients underwent an electrophysiologic study before and after SG block (electrophysiology study group). The subsequent seven patients had ambulatory Holter monitoring before and after SG block (ambulatory group). All patients underwent SG block on the right side first, and then on the left side. Selected patients who had heart rate reduction ≥15 beats per minute (bpm) were recommended to consider CSD.ResultsThe mean (SD) baseline heart rate (HR) was 106 (21) bpm. The HR significantly decreased to 93 (20) bpm (P = .02) at 10 minutes after right SG block and remained significantly slower at 97(19) bpm at 60 minutes. Left SG block reduced HR from 99 (21) to 87(16) bpm (P = .02) at 60 minutes. SG block had no significant effect on blood pressure or HR response to isoproterenol or exercise (all P > .05). Five patients underwent right (n = 4) or bilateral (n = 1) CSD. The clinical outcomes were heterogeneous: one patient had complete and two had partial symptomatic relief, and two did not have improvement.ConclusionSG blockade modestly reduces resting HR but has no significant effect on HR during exercise. Permanent CSD may have a modest role in alleviating symptoms in selected patients with IST.

AbstractIntroductionMyocardial infarction (MI) is associated with an increase in subsequent heart failure (HF), recurrent ischemic events, sudden cardiac arrest, and ventricular arrhythmias (SCA‐VA). The primary objective of the study to determine the role of intercurrent HF and ischemic events on the development of SCA‐VA following first type I MI.Methods and resultsA retrospective cohort study of patients experiencing first type 1 MI in Olmsted County, Minnesota (2002‐2012) was conducted by identifying patients using the medical records linkage system (Rochester epidemiology project). Patients aged ≥18 years were followed from the time of MI till death or 31 July, 2017. Intercurrent HF and ischemic events were the primary exposures following MI and their association with outcome SCA‐VA was assessed. Eight hundred and sixty‐seven patients (mean age was 63 ± 14.5 years; 69% male; 49.8% ST‐elevation myocardial infarction) who had their first type I MI during the study period were included. Majority of acute MI patients were revascularized using percutaneous coronary intervention and bypass surgery (628 [72.43%] and 87 [10.03%] respectively). During a mean follow‐up of 7.69 ± 4.17 years, HF, recurrent ischemic events and SCA‐VA occurred in 155 (17.9%), 245 (28.3%), and 40 (4.61%) patients respectively. Low ejection fraction (adjusted hazard ratio [HR] 0.95; 95% confidence interval [CI], 0.93‐0.98; P < .001), intercurrent HF (adjusted HR 3.11; 95% CI, 1.39‐6.95; P = .006) and recurrent ischemic events (adjusted HR 3.47; 95% CI, 1.68‐7.18; P < .001) were associated with subsequent SCA‐VA.ConclusionSCA‐VA occurred in a small proportion of patients after MI and is associated with intercurrent HF and recurrent ischemic events.

AbstractBackground and objectivesMacroreentrant atrial tachycardias often occur following atrial fibrillation ablation, most commonly due to nontransmural lesions in prior ablation lines. Perimitral atrial flutter is one such arrhythmia which requires ablation of the mitral isthmus. Our objectives were to review the literature regarding ablation of the mitral isthmus and to provide our approach for assessment of mitral isthmus block.MethodsWe review anatomical considerations, ablation strategies, and assessment of conduction block across the mitral isthmus, which is subject to several pitfalls. Activation sequence and spatial differential pacing techniques are discussed for assessment of both endocardial and epicardial bidirectional mitral isthmus block.ResultsTraditional methods for verifying mitral isthmus block include spatial differential pacing, activation mapping, and identification of double potentials. Up to 70% of cases require additional ablation in the coronary sinus (CS) to achieve transmural block. Interpretation of transmural block is subject to six pitfalls involving pacing output, differentiation of endocardial left atrial recordings from epicardial CS recordings, identification of a slowly conducting gap in the line, and catheter positioning during spatial differential pacing. Interpretation of unipolar electrograms can identify nontransmural lesions. We employ a combined epicardial and endocardial assessment of mitral isthmus block, which involves using a CS catheter for epicardial recording and a duodecapolar Halo catheter positioned around the mitral annulus for endocardial recording.ConclusionsThe assessment of transmural mitral isthmus block can be challenging. Placement of an endocardial mapping catheter around the mitral annulus can provide a precise assessment of conduction across the mitral isthmus.

BackgroundPatients with heart failure (HF) have increased risk for thromboembolic events. Real‐world incidences of efficacy and safety outcomes of direct oral anticoagulants (DOACs) in patients with left ventricular systolic dysfunction (LVSD) are of growing clinical interest.HypothesisReal‐world efficacy and safety outcomes of DOACs in patients with LVSD will be similar to those of LVSD or HF subgroups in the RE‐LY, ROCKET‐AF, and ARISTOTLE trials.MethodsWe performed a retrospective review of adult patients with LVSD (left ventricular ejection fraction ≤40%) on DOAC therapy between 2010 and 2016. Incidences of safety and efficacy outcomes of anticoagulation with DOACs were extracted from primary and secondary hospital discharge diagnoses.ResultsDOACs were prescribed to 287 patients with LVSD over a mean follow‐up of 313.3 ± 52.3 days. Many patients had moderate and severe chronic kidney disease (28.9% and 10.1%, respectively) and indications for anticoagulation therapy other than atrial fibrillation (19.9%). For efficacy outcomes, the calculated incidence rates of ischemic stroke and systemic embolism were 1.2 (95% confidence interval [CI]: 0.25‐3.56) and 0.81 (95% CI: 0.10‐2.94) events per 100 person‐years, respectively. For the safety outcomes, incidence rates of GI bleeding and intracranial hemorrhage were 2.4 (95% CI: 0.8‐5.3) and 0.41 (95% CI: 0.1‐2.2) events per 100 patient‐years, respectively.ConclusionsOur findings are largely compatible with the results of LVSD or HF subgroups in RE‐LY, ROCKET‐AF, and ARISTOTLE trials and add to increasing confidence that DOACs can be safely used for stroke and systemic embolism prevention in patients with LVSD.

BackgroundAlthough sudden death (SD) is a rare complication after atrioventricular junction (AVJ) ablation and permanent pacemaker implantation, the risk factors leading to this SD remain unknown. The purpose of this study was to investigate SD and its risk factors after ablate‐and‐pace strategy for rate control in atrial fibrillation (AF) patients during long‐term follow‐up.HypothesisMethodsFrom January 2005 to December 2009, we enrolled into this study 517 AF patients with AVJ ablation and right ventricular pacemaker implantation. Patients were divided into 2 groups, SD and non‐SD. Cox proportional hazards models were used to assess potential risk factors for overall mortality and SD.ResultsDuring a mean follow‐up of 25.8 ± 18.6 months (range, 3 days to 63.8 months), 53 patients died (15 with SD). Cox proportional hazards models showed that the presence of congestive heart failure, New York Heart Association functional class, chronic renal failure, and nonsustained ventricular tachycardia were risk factors that predicted overall mortality. For SD, the presence of dilated cardiomyopathy and mitral stenosis were associated risk factors. SD was exclusively seen in patients who had narrow QRS complex or right bundle branch block prior to AVJ ablation and pacemaker implantation; SD was not seen in any patient with preexisting complete left bundle branch block.ConclusionsDilated cardiomyopathy, mitral stenosis, and baseline QRS morphology should be examined as potential risk factors for SD after AVJ ablation and pacemaker implantation.

PurposeAutoantibodies are implicated in the pathogenesis of cardiovascular diseases and cardiac arrhythmias. In this pilot study, we tested the hypothesis that autoantibodies are present in patients with postural orthostatic tachycardia syndrome (POTS).Experimental designSeven control subjects (6 F:1 M, average age 36.1 years) and ten patients with the diagnosis of POTS (7 F: 3 M, average age 35.1 years) provided informed consent and 30 mL of venous blood. Human heart membrane proteins were resolved by 2DE and immunoblotted against purified IgGs from controls and patients.ResultsEighteen protein spots immunoreactive specifically against patient IgGs were detected and they were excised from gels, trypsin‐digested, and analyzed by nanoLC‐electrospray MS/MS. Forty unique proteins were identified and these include proteins that are associated with cardiac hypertrophy (mimecan, myozenin), cardiac remodeling (periostin), cardiomyopathy (desmin, desmoplakin), cell survival (laminin), structural integrity (filamin), chaperone proteins (crystalline, HSP70), mitochondrial enzymes, and channel proteins. Ingenuity Pathway Analysis showed multiple pathways were involved including those that regulate energy metabolism, redox, fibrosis, cardiac hypertrophy, and degeneration.Conclusions and clinical relevanceAutoantibodies are present in patients with POTS. These autoantibodies cross‐react with a wide range of cardiac proteins and may induce alterations in cardiac function. Autoimmune pathogenetic mechanisms should be further explored in these patients.