Diverse Phenotypic Manifestations in a Family with a Novel RYR2 E4107A Variant.

Cardiac ryanodine receptor (RyR2) gain-of-function mutations cause catecholaminergic polymorphic ventricular tachycardia (CPVT). Conversely, RyR2 loss-of-function mutations cause a new disease entity, termed calcium release deficiency syndrome (CRDS), which may include RYR2-related long QT syndrome (LQTS). Importantly, unlike CPVT, patients with CRDS do not always exhibit exercise- or epinephrine-induced ventricular arrhythmias, which precludes a diagnosis of CRDS. Here we report a boy and his father, who both experienced exercise-induced cardiac events and harbor the same RYR2 E4107A variant. In the boy, an exercise stress test (EST) and epinephrine provocation test (EPT) did not induce any ventricular arrhythmias. QTc was slightly prolonged (QTc: 474 ms), and an EPT induced QTc prolongation (QTc-baseline: 466 ms, peak: 532 ms, steady-state: 527 ms). In contrast, in his father, QTc was not prolonged (QTc: 417 ms), and neither an EST nor EPT induced QTc prolongation. However, an EST induced multifocal premature ventricular contraction (PVC) bigeminy and bidirectional PVC couplets. Thus, they exhibited distinct clinical phenotypes: the boy exhibited LQTS (or CRDS) phenotype, whereas his father exhibited CPVT phenotype. These findings suggest that, in addition to the altered RyR2 function, other unidentified factors, such as other genetic, epigenetic, and environmental factors, and aging, may be involved in the diverse phenotypic manifestations. Considering that a single RYR2 variant can cause both CPVT and LQTS (or CRDS) phenotypes, in cascade screening of patients with CPVT and CRDS, an EST and EPT are not sufficient and genetic analysis is required to identify individuals who are at increased risk for life-threatening arrhythmias.

Prevalence and Predictors of Mitral Annular Disjunction and Ventricular Ectopy in Mitral Valve Prolapse.

BACKGROUND: Mitral annular disjunction (MAD) is associated with ventricular arrhythmia in mitral valve prolapse (MVP). The proportional risk from MAD and other predictors of ventricular arrhythmia in MVP have not been well characterized. OBJECTIVE: To identify predictors of complex or frequent ventricular ectopy (cfVE) in MVP and quantify risk of cfVE and mortality in MVP with MAD. METHODS: We studied 632 adult patients with MVP on transthoracic echocardiography at the University of North Carolina Medical Center from 2016-2019 (median age [IQR] 64 [52-74] years; 52.7% female; 16.3% African American). Resting and ambulatory electrocardiograms were used to identify cfVE. RESULTS: MAD was present in 94 (14.9%) patients. Independent associations of MAD were bileaflet prolapse (OR [95% CI] 4.25 [2.47-7.33], p<0.0001), myxomatous valve (2.17 [1.27-3.71], p=0.005), absence of hypertension (2.00 [1.21-3.32], p=0.007), electrocardiogram inferior or lateral lead T-wave inversion (TWI, 2.07 [1.23-3.48], p=0.006), and female sex (1.99 [1.21-3.25], p=0.006). cfVE was frequent with MAD (39 [41.5%] vs 93 [17.3%] without, p<0.0001). Independent cfVE predictors were MAD (HR [95% CI] 2.23 [1.47-3.36], p=0.0001), bileaflet prolapse (1.86 [1.25-2.76], p=0.002), heart failure (1.79 [1.16-2.77], p=0.009), lower LV ejection fraction (0.14 [0.03-0.61], p=0.009), coronary artery disease (1.60 [1.05-2.43], p=0.03), and TWI (1.51 [1.03-2.22], p=0.03). After median 40 (33-48) months, there was increased mortality with MAD (p=0.04). CONCLUSION: MAD in MVP is associated with bileaflet or myxomatous MVP, absence of hypertension, T-wave inversion, and female sex. There is increased complex and frequent ventricular ectopy and mortality with MAD, highlighting the need for closer follow-up in these patients.

Potential Microemboli Formation Risk and its Management during the Heated Saline Enhanced Radiofrequency (SERF) Needle-tip Catheter Ablation.

BACKGROUND: The potential risk of embolic events during ablation in the left ventricle (LV) with a heated saline-enhanced radiofrequency needle-tip ablation catheter (SERF) has not been characterized. OBJECTIVE: This study aims to investigate formation of microemboli or other untoward events during SERF ablation. METHODS: Ninety-three radiofrequency (RF) ablations were performed in the LV of 14 pigs using a SERF (35W, 70 sec and 60°C normal or degassed saline [NS or DS] irrigation with a flow rate of 10mL/min) versus a standard irrigated-tip RF catheter (S-RF) (30 or 50W, 30sec, and 17ml/min). Microbubble formation was graded based on intracardiac echography (ICE). Microbubbles, microembolic signals and microparticles were monitored using our established model. RESULTS: There was no significant difference in microbubble volume among SERF-NS, SERF-DS and S-RF 30W with "Grade 1" ICE microbubble grade (0.201µL [0.011-3.13], 0.455µL [0.06-2.66] and 0.004µL [0.00-0.16], median [quartiles], respectively). There was no significant difference in microembolic signals among SERF-NS, SERF-DS, and S-RF 30W with "Grade 1" bubbles (n=8.0±5.8, 7.6±4.2 and 6.1±6.1, respectively). Both SERF-NS and SERF-DS created larger lesions than both S-RF 30 and 50W deliveries (1241.5±658.6mm3, 1497.7±893.4mm3, 75.0±24.8mm3 and 184.0±93.8mm3, mean±standard deviation, p<0.001). There was no significant difference in the microparticle incidence among groups (p=0.675). No evidence of embolic events was found in the brain and other organs at the histology assessment. CONCLUSIONS: In the setting of SERF ablation, significantly large LV lesion can be created without any increment in embolic microbubble or particle events. Grade 1 microbubble is related to the efficacy and safety.

Aberrancy masquerading as ventricular tachycardia: Importance of invasive electrophysiology study for diagnosis of wide complex tachycardias.

BACKGROUND: Differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT) with aberrancy based on the 12­lead ECG alone can be imprecise. Implantable cardiac defibrillators (ICD) may be inserted for presumed VT, particularly in patients with syncopal presentation or atypical aberrancy patterns. Accurate diagnosis of these patients facilitated by an electrophysiology study (EPS) may alter diagnosis and management. METHODS: We present a prospective collection of cases across 3 cardiac centers of consecutive patients with WCT presumed to be VT who were referred for consideration of an ICD, and in whom further evaluation including an EPS ultimately demonstrated SVT with aberrancy as the culprit arrhythmia. RESULTS: 22 patients were identified (17 male, mean age 50±13 years. Available rhythm data at the time of referral was presumptively diagnosed as monomorphic VT in 16 patients and polymorphic VT in 6 patients. Underlying structural heart disease was present in 20 (91%). EPS resulted in a diagnosis of SVT with aberrancy in all cases: comprising AV nodal re-entry tachycardia (n=10), orthodromic reciprocating tachycardia (n=3), focal atrial tachycardia (n=3), AF/AFL (n=3) and 'double fire' tachycardia (n=2). 21 (95%) patients underwent successful ablation. All patients remained free of arrhythmia recurrence at a median of 3.4 years of follow-up. ICD insertion was obviated in 18 (82%) patients, with 1 patient proceeding to ICD extraction. CONCLUSION: SVT with atypical aberrancy may mimic monomorphic or polymorphic VT. Careful examination of all available rhythm data and consideration of an EPS can confirm SVT and obviate the need for ICD therapy.

Wide Complex Tachycardia as a Rare Pointer of Intra-aortic Balloon Pump Migration Into the Left Ventricle: A Case Report and Literature Review.

Intra-aortic balloon pumps (IABPs) are used to assist with left ventricular (LV) unloading in patients with cardiogenic shock (CS). There are different mechanical devices that can be used in CS, of which the IABP represents the simplest, the easiest to insert and remove, and the most cost-effective. Compared to traditional femoral IABPs, axillary IABPs allow patients to remain ambulatory. This is especially beneficial in patients awaiting heart transplants. Our case presents a patient with CS, where axillary IABP was used to unload the LV. However, our patient developed ventricular arrhythmia secondary to IABP migration to the LV.

Automatic Implantable Cardioverter Defibrillator (AICD) Implantation as Secondary Prevention of Cardiac Sarcoidosis-Associated Ventricular Tachycardia.

Background: Cardiac sarcoidosis can cause a wide range of symptoms, including shortness of breath, chest pain, oedema, and fatal arrhythmias such as ventricular tachycardia (VT). Because the symptoms can be nonspecific, diagnosing cardiac sarcoidosis can be challenging. Treatment options may include corticosteroids to reduce inflammation, immunosuppressive drugs to prevent further damage, medications to control symptoms, ablation procedures, and defibrillators to prevent cardiac arrest. Case: A 60-year-old woman who has sarcoidosis affecting multiple organs including cardiac sarcoidosis, non-ischemic cardiomyopathy with reduced ejection fraction, and hypertension, was admitted with tachycardia, shortness of breath, and a recently fired automatic implantable cardioverter defibrillator (AICD). Three months prior, the patient was admitted for a syncopal episode and diagnosed with cardiac sarcoidosis through cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET), which demonstrated active inflammation, and an AICD was implanted. During this admission, the patient had an episode of ventricular tachycardia and was treated with amiodarone and lidocaine. The patient received steroids, sacubitril/valsartan, and methotrexate. After 48 hours of observation, the patient was discharged without further events. Conclusion: Cardiac sarcoidosis is a rare but serious disease that can lead to life-threatening cardiac complications such as ventricular tachycardia. Early diagnosis and aggressive management are crucial for improving outcomes and preventing sudden cardiac death. AICD implantation as a secondary prevention in cardiac sarcoidosis might prevent cardiac arrest." LEARNING POINTS: Cardiac sarcoidosis can present with non-specific symptoms and lead to life-threatening arrhythmias such as ventricular tachycardia, emphasising the importance of early diagnosis and aggressive management to prevent sudden cardiac death.A multidisciplinary approach involving imaging modalities such as cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, along with histological findings, is crucial for accurately diagnosing cardiac sarcoidosis, as endomyocardial biopsy alone has low sensitivity.Implantation of an automatic implantable cardioverter defibrillator (AICD) as a secondary prevention measure should be considered in cardiac sarcoidosis patients, even in elderly individuals with mildly to moderately reduced ejection fraction, to prevent fatal arrhythmias and sudden cardiac death.

Catastrophic Implantable Cardioverter-Defibrillator Misclassification of Ventricular Tachycardia.

Inappropriate therapy is a frequent adverse consequence of implantable cardioverter-defibrillator. Inappropriate therapy often occurs due to the misinterpretation of sinus tachycardia or atrial fibrillation/flutter with rapid atrioventricular conduction by the device. Current implantable cardioverter-defibrillator (ICD) mechanisms integrate various discriminators into algorithms to differentiate supraventricular tachycardia (SVT) from ventricular tachycardia (VT), to prevent such occurrences. A 40-year-old man suffered seizures and cardiac arrest abruptly, without prior complaints of chest pain. Without delay, he initiated cardiopulmonary resuscitation (CPR), resulting in the regaining of spontaneous circulation. The patient had previously received a single-chamber ICD due to recurring VT and a prior episode of cardiac arrest. The patient had a medical background of coronary artery disease with complete revascularisation and no previous occurrence of SVT. Interrogating the ICD revealed captured non-sustained ventricular tachycardia (NSVT) and SVT events but no VT episode or shock therapy. During the specified time period, the patient underwent an electrophysiological study, and no SVT was induced with the normal function of the atrioventricular and sinoatrial nodes. Various causes can lead to errors in morphology discrimination criteria in single-chamber ICDs. Extending the detection interval is highly recommended to avoid misclassification of ICDs. LEARNING POINTS: This highlights the crucial significance of precise classification of supraventricular tachycardia (SVT) and ventricular tachycardia (VT) using a single-chamber implantable cardioverter-defibrillator (ICD) discriminator to guarantee prompt and appropriate therapy delivery.The morphology criterion used in single-chamber ICDs may have potential limits and inaccuracies, which might result in the misdiagnosis of VT as SVT.Further study and enhancement of differentiation algorithms, paired with precise programming and prolonged detection durations are essential to reduce such misclassifications and improve patient outcomes.

RIPPLE-VT Study: Multicentre, prospective evaluation of ventricular tachycardia substrate ablation by targeting scar channels to eliminate latest scar potentials without direct ablation.

BACKGROUND: Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction. Better defining this arrhythmic substrate could help improve outcome and reduce ablation burden. OBJECTIVE: Limiting ablation within post-infarct scar to conduction channels within the scar to reduce VT recurrence. METHODS: Patients undergoing catheter ablation for recurrent implantable defibrillator (ICD) therapy for post-infarct VT were recruited at 5 centres. Left ventricular maps were collected on CARTO™ using a Pentaray™ catheter. Ripple mapping was used to categorise infarct scar potentials (SPs) by timing. Earliest SPs were ablated sequentially until there was loss of the terminal scar potentials without their direct ablation. The primary outcome measure was sustained VT episodes as documented by device interrogations at 1yr and was compared with VT episodes in the year pre-ablation. RESULTS: 50 pts were recruited (mean LVEF 33%±9) and 37pts (74%) met channel ablation endpoint with successful loss of latest SPs without direct ablation. There were 16 recurrences during 1yr follow up. There was a 90% reduction in VT burden from 30.2±53.9 to 3.1±7.5 (p<0.01) per patient, with a concomitant 88% reduction in appropriate shocks from 2.1±2.7 to 0.2±0.9 (p<0.01). There were 8 deaths during follow-up. Those who met channel ablation endpoint had no significant difference in mortality, recurrence or VT burden but had a significantly lower ablation burden 25.7±4.2 vs 39.9±6.1 mins (p=0.001). CONCLUSION: Scar channel ablation is feasible using ripple mapping and can be an alternative to more extensive substrate modification techniques.

Wavefront Curvature Analysis Derived from Pre-Procedural Imaging Can Identify the Critical Isthmus in Patients with Post-Infarcted Ventricular Tachycardia.

BACKGROUND: Where activation wavefront curvature is convexly shaped, functional conduction block can occur. OBJECTIVE: We sought to determine whether left ventricular (LV) wall thickness determined from contrast-enhanced computed tomography (CT) is useful to localize such areas in clinical postinfarction reentrant ventricular tachycardia (VT). METHODS: We evaluated data from six patients who underwent catheter ablation for postinfarction VT. CT imaging with inHEART processing was conducted 1-3 days in advance of electrophysiology (EP) study to determine LV wall thickness (T). Activation wavefront curvature was approximated as ΔT/T, where ΔT represents wall thickness change. During EP study, bipolar left ventricular VT electrograms were acquired using a high-density mapping catheter, and activation times were determined. Maps of T, ΔT/T, and VT activation were subsequently compared using statistical analyses. RESULTS: Two of six cases exhibited dual circuit morphologies, resulting in a total of eight VT morphologies analyzed. The LV wall near the VT isthmus location tended to be thin, on the order of a few hundred microns. Regions of largest ΔT/T partially coincided with the lateral isthmus boundaries where electrical conduction block occurred during VT. ΔT/T at the boundaries, measured from imaging, was significantly larger as compared to values at the isthmus midline, and compared to the global LV mean value (p<0.001). CONCLUSION: Wavefront curvature measured by ΔT/T and caused by source-sink mismatch is dependent upon ventricular wall thickness. Areas of high wavefront curvature partly coincide with and may be useful to help locate the VT isthmus in infarct border zones using pre-procedural imaging analysis.

Periprocedural acute haemodynamic decompensation during substrate-based ablation of scar-related ventricular tachycardia: a rare and unpredictable event.

AIMS: Patients with structural heart disease (SHD) undergoing catheter ablation (CA) for ventricular tachycardia (VT) are at considerable risk of periprocedural complications, including acute haemodynamic decompensation (AHD). The PAINESD score was proposed to predict the risk of AHD. The goal of this study was to validate the PAINESD score using the retrospective analysis of data from a large-volume heart centre. METHODS AND RESULTS: Patients who had their first radiofrequency CA for SHD-related VT between August 2006 and December 2020 were included in the study. Procedures were mainly performed under conscious sedation. Substrate mapping/ablation was performed primarily during spontaneous rhythm or right ventricular pacing. A purposely established institutional registry for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated using the source medical records. Acute haemodynamic decompensation triggered by CA procedure was defined as intraprocedural or early post-procedural (<12 h) development of acute pulmonary oedema or refractory hypotension requiring urgent intervention. The study cohort consisted of 1124 patients (age, 63 ± 13 years; males, 87%; ischaemic cardiomyopathy, 67%; electrical storm, 25%; New York Heart Association Class, 2.0 ± 1.0; left ventricular ejection fraction, 34 ± 12%; diabetes mellitus, 31%; chronic obstructive pulmonary disease, 12%). Their PAINESD score was 11.4 ± 6.6 (median, 12; interquartile range, 6-17). Acute haemodynamic decompensation complicated the CA procedure in 13/1124 = 1.2% patients and was not predicted by PAINESD score with AHD rates of 0.3, 1.8, and 1.1% in subgroups by previously published PAINESD terciles (<9, 9-14, and >14). However, the PAINESD score strongly predicted mortality during the follow-up. CONCLUSION: Primarily substrate-based CA of SHD-related VT performed under conscious sedation is associated with a substantially lower rate of AHD than previously reported. The PAINESD score did not predict these events. The application of the PAINESD score to the selection of patients for pre-emptive mechanical circulatory support should be reconsidered.

The Safety and Efficacy of Epicardial Carbon Dioxide Insufflation Compared With Conventional Epicardial Access.

BACKGROUND: Epicardial (Epi) access is commonly required during ventricular tachycardia ablation. Conventional Epi (ConvEpi) access targets a "dry" pericardial space presenting technical challenges and risk of complications. Recently, intentional puncture of coronary venous branches with Epi carbon dioxide insufflation (EpiCO2) has been described as a technique to improve Epi access. The safety of this technique relative to conventional methods remains unproven. OBJECTIVES: The authors sought to compare the feasibility and safety of EpiCO2 to ConvEpi access. METHODS: All patients at a high-volume center undergoing Epi access between January 2021 and December 2023 were included and grouped according to ConvEpi or EpiCO2 approach. Access technique was according to the discretion of the operator. RESULTS: Epi access was attempted in 153 cases by 17 different operators (80 ConvEpi vs 73 EpiCO2). There was no difference in success rate whether the ConvEpi or EpiCO2 approach was used (76 [95%] cases vs 67 [91.8%] cases; P = 0.4). Total Epi access time was shorter in the ConvEpi group compared with the EpiCO2 group (16.3 ± 11.6 minutes vs 26.9 ± 12.7 minutes; P < 0.001), though the total procedure duration was similar. Major Epi access-related complications occurred in only the ConvEpi group (6 [7.5%] ConvEpi vs 0 [0%] EpiCo2; P = 0.02). Bleeding ≥80 mL was more frequently observed following ConvEpi access (14 [17.5%] cases vs 4 [5.5%] cases; P = 0.02). After adjusting for age, repeat Epi access, and antithrombotic therapy, EpiCO2 was associated with a reduction in bleeding ≥80 mL (OR: 0.27; 95% CI: 0.08-0.89; P = 0.03). CONCLUSIONS: EpiCO2 access is associated with lower rates of major complication and bleeding when compared with ConvEpi access.

Percutaneous left stellate ganglion block for refractory ventricular tachycardia in structural heart disease: our single-centre experience.

INTRODUCTION: When electrical storm (ES) is amenable to neither antiarrhythmic drugs, nor deep sedation or catheter ablation, autonomic modulation may be considered. We report our experience with percutaneous left stellate ganglion block (PSGB) to temporarily suppress refractory ventricular arrhythmia (VA) in patients with structural heart disease. METHODS: A retrospective analysis was performed at our institution of patients with structural heart disease and an implantable cardioverter defibrillator (ICD) who had undergone PSGB for refractory VA between January 2018 and October 2021. The number of times antitachycardia pacing (ATP) was delivered and the number of ICD shocks/external cardioversions performed in the week before and after PSGB were evaluated. Charts were checked for potential complications. RESULTS: Twelve patients were identified who underwent a combined total of 15 PSGB and 5 surgical left cardiac sympathetic denervation procedures. Mean age was 73 ± 5.8 years and all patients were male. Nine of 12 (75%) had ischaemic cardiomyopathy, with the remainder having non-ischaemic dilated cardiomyopathy. Mean left ventricular ejection fraction was 35% (±â€¯12.2%). Eight of 12 (66.7%) patients were already being treated with both amiodarone and beta-blockers. The reduction in ATP did not reach statistical significance (p = 0.066); however, ICD shocks (p = 0.028) and ATP/shocks combined were significantly reduced (p = 0.04). At our follow-up electrophysiology meetings PSGB was deemed ineffective in 4 of 12 patients (33%). Temporary anisocoria was seen in 2 of 12 (17%) patients, and temporary hypotension and hoarseness were reported in a single patient. DISCUSSION: In this limited series, PSGB showed promise as a method for temporarily stabilising refractory VA and ES in a cohort of male patients with structural heart disease. The side effects observed were mild and temporary.

Road-Map to Epicardial Approach for Catheter Ablation of Ventricular Tachycardia in Structural Heart Disease: Results From a 10-Year Tertiary-Center Experience.

BACKGROUND: Epicardial approach in ventricular tachycardia (VT) ablation is still regarded as a second-step strategy, due to the risk of complications. We evaluated the frequency that epicardial ablation targets were identified and ablation performed following pericardial access compared with unnecessary pericardial access for different VT causes and potential markers of epicardial VT. METHODS: All VT ablation procedures including epicardial approach over a 10-year period were included. First-line epicardial approach was indicated in arrhythmogenic right ventricular cardiomyopathy (ARVC) and postmyocarditis VT; in patients with idiopathic dilated cardiomyopathy (IDCM) and postmyocardial infarction, indications resulted from available imaging techniques or 12-lead VT morphology. The epicardial approach was considered useful if epicardial ablation was performed after epicardial mapping. Feasibility, complications, and long-term outcome were reported. RESULTS: Four hundred and eighty-eight subjects with a median age of 60 years (interquartile range, 47-65) and of left ventricle ejection fraction 41% (interquartile range, 30-55) underwent 626 epicardial VT ablations. Percutaneous access had a success rate of 92.2% and a complication rate of 3.6%. Overall, epicardial approach was, respectively, indicated to 11.8% of postmyocardial infarction patients, 49.5% in IDCM, 94% in myocarditis, and 90.7% in ARVC. Epicardial ablation at the first ablation attempt was performed in 9.3% of postmyocardial infarction patients, 28.8% in IDCM, 86.5% in myocarditis, and 81.3% in patients with ARVC. In first-line epicardial group, ARVC and myocarditis showed the highest odds for epicardial ablation (OR, 4.057 [95% CI, 1.299-8.937]; P=0.007; OR, 3.971 [95% CI, 1.376-11.465]; P=0.005, respectively). IDCM independently predicted unnecessary epicardial approach (OR, 2.7 [95% CI, 1.7-4.3]; P<0.001). After a follow-up of 41 months (interquartile range, 19-64), patients with IDCM experienced higher rate of recurrences and mortality compared with other causes. CONCLUSIONS: Epicardial approach is integral part of ablation armamentarium regardless of the VT cause, with high feasibility and low complication rate in experienced centers. Our data support its use at first ablation attempt in VTs related to ARVC and myocarditis.

A Case of Left Ventricular Pseudoaneurysm as a Complication of Late-Presenting ST-Segment Elevation Myocardial Infarction.

This case report delineates the clinical trajectory and management strategies of a 59-year-old Hispanic male diagnosed with a left ventricular pseudoaneurysm (LVPA) following a delayed presentation of ST-segment elevation myocardial infarction (STEMI), for which reperfusion treatment was not administered. Initially, an echocardiogram demonstrated an extensive anterolateral myocardial infarction, severe left ventricular systolic dysfunction, and an early-stage left ventricular apical aneurysm with thrombus, leading to the initiation of warfarin. Metabolic myocardial perfusion imaging via positron emission tomography indicated a substantial myocardial scar without viability, guiding the decision against revascularization. Post discharge, the patient, equipped with a wearable cardioverter defibrillator for sudden cardiac death prevention, experienced symptomatic ventricular tachycardia, which was resolved with defibrillator shocks. Subsequent imaging revealed an acute LVPA adjacent to the existing left ventricular aneurysm. Given the high surgical risk, conservative management was elected, resulting in thrombosis and closure of the pseudoaneurysm after two weeks. The patient eventually transitioned to home hospice, surviving an additional five months. This report underscores the complexities and therapeutic dilemmas in managing post-MI LVPA patients who are ineligible for surgical intervention.

Sympathetic Duet: Simultaneous Stellate Ganglion Block and Thoracic Epidural Analgesia in the Successful Termination of Ventricular Storm.

This article discusses the management of ventricular storm (VS), a condition characterized by recurrent episodes of sustained ventricular tachycardia or fibrillation, which poses a significant risk of mortality. Prompt intervention is crucial, yet surgical options are often limited due to the patient's unstable condition. This case report presents a 47-year-old female who experienced VS during a planned surgical procedure. Despite initial stabilization, she continued to experience life-threatening arrhythmias, prompting the implementation of simultaneous stellate ganglion block (SGB) and thoracic epidural analgesia (TEA) catheters. This combined approach successfully controlled the arrhythmias, allowing for subsequent surgical interventions. The article emphasizes the potential of SGB and TEA as a bridge to definitive therapies for refractory VS, highlighting the need for further research to solidify their role in clinical practice.

Antiarrhythmic effects of metformin.

Atrial fibrillation/flutter (AF) is a major public health problem and is associated with stroke, heart failure, dementia, and death. It is estimated that 20%-30% of Americans will develop AF at some point in their life. Current medications to prevent AF have limited efficacy and significant adverse effects. Newer and safer therapies to prevent AF are needed. Ventricular arrhythmias are less prevalent than AF but may have significant consequences including sudden cardiac death. Metformin is the most prescribed, first-line medication for treatment of diabetes mellitus (DM). It decreases hepatic glucose production but also reduces inflammation and oxidative stress. Experimental studies have shown that metformin improves metabolic, electrical, and histologic risk factors associated with AF and ventricular arrhythmias. Furthermore, in large clinical observational studies, metformin has been associated with a reduced risk of AF in people with DM. These data suggest that metformin may have antiarrhythmic properties and may be a candidate to be repurposed as a medication to prevent cardiac arrhythmias. In this article, we review the clinical observational and experimental evidence for the association between metformin and cardiac arrhythmias. We also discuss the potential antiarrhythmic mechanisms underlying this association. Repurposing a well-tolerated, safe, and inexpensive medication to prevent cardiac arrhythmias has significant positive public health implications.

Sudden cardiac arrest occurring in temporal proximity to consumption of energy drinks.

BACKGROUND: Energy drinks potentially can trigger life-threatening cardiac arrhythmias. It has been postulated that the highly stimulating and unregulated ingredients alter heart rate, blood pressure, cardiac contractility, and cardiac repolarization in a potentially proarrhythmic manner. OBJECTIVE: The purpose of this study was to describe our experience regarding sudden cardiac arrest (SCA) occurring in proximity to energy drink consumption in patients with underlying genetic heart diseases. METHODS: The electronic medical records of all SCA survivors with proven arrhythmias referred to the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic for evaluation were reviewed to identify those who consumed an energy drink before their event. Patient demographics, clinical characteristics, documented energy drink consumption, and temporal relationship of energy drink consumption to SCA were obtained. RESULTS: Among 144 SCA survivors, 7 (5%; 6 female; mean age at SCA 29 ± 8 years) experienced an unexplained SCA associated temporally with energy drink consumption. Of these individuals, 2 had long QT syndrome and 2 had catecholaminergic polymorphic ventricular tachycardia; the remaining 3 were diagnosed with idiopathic ventricular fibrillation. Three patients (43%) consumed energy drinks regularly. Six patients (86%) required a rescue shock, and 1 (14%) was resuscitated manually. All SCA survivors have quit consuming energy drinks and have been event-free since. CONCLUSION: Overall, 5% of SCA survivors experienced SCA in proximity to consuming an energy drink. Although larger cohort studies are needed to elucidate the incidence/prevalence and quantify its precise risk, it seems prudent to sound an early warning on this potential risk.

Mode and Characteristics of Arrhythmia Initiation in Idiopathic Ventricular Fibrillation: A THESIS Substudy.

BACKGROUND: There is limited information on the mode of arrhythmia initiation in idiopathic ventricular fibrillation (IVF). A non-pause-dependent mechanism has been suggested to be the rule. OBJECTIVES: The aim of this study was to assess the mode and characteristics of initiation of polymorphic ventricular tachycardia (PVT) in patients with short or long-coupled PVT/IVF included in THESIS (THerapy Efficacy in Short or long-coupled idiopathic ventricular fibrillation: an International Survey), a multicenter study involving 287 IVF patients treated with drugs or radiofrequency ablation. METHODS: We reviewed the initiation of 410 episodes of ≥1 PVT triplet in 180 patients (58.3% females; age 39.6 ± 13.6 years) with IVF. The incidence of pause-dependency arrhythmia initiation (prolongation by >20 ms of the preceding cycle length) was assessed. RESULTS: Most arrhythmias (n = 295; 72%) occurred during baseline supraventricular rhythm without ambient premature ventricular complexes (PVCs), whereas 106 (25.9%) occurred during baseline rhythm including PVCs. Nine (2.2%) arrhythmias occurred during atrial/ventricular pacing and were excluded from further analysis. Mode of PVT initiation was pause-dependent in 45 (15.6%) and 64 (60.4%) of instances in the first and second settings, respectively, for a total of 109 of 401 (27.2%). More than one type of pause-dependent and/or non-pause-dependent initiation (mean: 2.6) occurred in 94.4% of patients with ≥4 events. Coupling intervals of initiating PVCs were <350 ms, 350-500 ms, and >500 ms in 76.6%, 20.72%, and 2.7% of arrhythmia initiations, respectively. CONCLUSIONS: Pause-dependent initiation occurred in more than a quarter of arrhythmic episodes in IVF patients. PVCs having long (between 350 and 500 ms) and very long (>500 ms) coupling intervals were observed at the initiation of nearly a quarter of PVT episodes.