Cardiac Sarcoidosis-Diagnostic and Therapeutic Challenges.

Sarcoidosis is a multisystem disorder of unknown etiology. The leading hypothesis involves an antigen-triggered dysregulated T-cell-driven immunologic response leading to non-necrotic granulomas. In cardiac sarcoidosis (CS), the inflammatory response can lead to fibrosis, culminating in clinical manifestations such as atrioventricular block and ventricular arrhythmias. Cardiac manifestations frequently present as first and isolated signs or may appear in conjunction with extracardiac manifestations. The incidence of sudden cardiac death (SCD) is high. Diagnosis remains a challenge. For a definite diagnosis, endomyocardial biopsy (EMB) is suggested. In clinical practice, compatible findings in advanced imaging using cardiovascular magnetic resonance (CMR) and/or positron emission tomography (PET) in combination with extracardiac histological proof is considered sufficient. Management revolves around the control of myocardial inflammation by employing immunosuppression. However, data regarding efficacy are merely based on observational evidence. Prevention of SCD is of particular importance and several guidelines provide recommendations regarding device therapy. In patients with manifest CS, outcome data indicate a 5-year survival of around 90% and a 10-year survival in the range of 80%. Data for patients with silent CS are conflicting; some studies suggest an overall benign course of disease while others reported contrasting observations. Future research challenges involve better understanding of the immunologic pathogenesis of the disease for a targeted therapy, improving imaging to aid early diagnosis, assessing the need for screening of asymptomatic patients and randomized trials.

In-Hospital Pulmonary Arterial Embolism after Catheter Ablation of Over 45,000 Cardiac Arrhythmias: Individualized Case Analysis of Multicentric Data.

OBJECTIVE AND BACKGROUND: Data on incidence of in-hospital pulmonary embolisms (PE) after catheter ablation (CA) are scarce. To gain further insights, we sought to provide new findings through case-based analyses of administrative data. METHODS: Incidences of PE after CA of supraventricular tachycardias (SVT), atrial fibrillation (AF), atrial flutter (AFlu), and ventricular tachycardias (VT) in three German tertiary centers between 2005 and 2020 were determined and coded by the G-DRG (German Diagnosis Related Groups System) and OPS (German Operation and Procedure Classification) systems. An administrative search was performed with a consecutive case-based analysis. RESULTS: Overall, 47,344 ablations were analyzed (10,037 SVT; 28,048 AF; 6,252 AFlu; 3,007 VT). PE occurred in 14 (0.03%) predominantly female (n = 9; 64.3%) patients with a mean age of 55.3 ± 16.9 years, body mass index 26.2 ± 5.1 kg/m2, and left ventricular ejection fraction of 56 ± 13.6%. PE incidences were 0.05% (n = 5) for SVT, 0.02% (n = 5) for AF, and 0.13% (n = 4) for VT ablations. No patient suffered PE after AFlu ablation. Five patients (35.7%) with PE after CA had no prior indication for oral anticoagulation (OAC). Preprocedural international normalized ratio in PE patients was 1.2 ± 0.5. Most patients with PE following CA presented with symptoms the day after the procedure (n = 9) after intraprocedural heparin application of 12,943.2 ± 5,415.5 IU. PE treatment included anticoagulation with either phenprocoumon (n = 5) or non-vitamin K-dependent OAC (n = 9). Two patients with PE died after VT/AF ablation, respectively. The remaining patients were discharged without sequels. CONCLUSION: Over a 15-year period, incidence of PE after ablation is low, particularly low in patients with ablation for AF/AFlu. This is most likely due to stricter anticoagulation management in these patients compared with those receiving SVT/VT ablation procedures and could argue for continuation of OAC prior to ablation. Optimizing periprocedural anticoagulation management should be subject of further prospective trials.

Validation of the PRAETORIAN score in a large subcutaneous implantable cardioverter-defibrillator collective: Usefulness in clinical routine.

BACKGROUND: To assess the risk of unsuccessful conversion of ventricular fibrillation during defibrillation testing (DFT) with the subcutaneous implantable cardioverter-defibrillator (S-ICD), the PRAETORIAN score has been proposed. OBJECTIVE: The purpose of this study was to validate the PRAETORIAN score in a large S-ICD collective. METHODS: A retrospective single-center analysis of S-ICD patients receiving intraoperative DFT was performed. DFT was performed using a stepwise protocol with 65-J standard polarity, change of polarity, increase to 80 J, and repositioning if necessary. If all DFTs failed, we switched to a transvenous ICD. RESULTS: Overall, 398 patients were analyzed (268 male [67.3%]; mean age 42.4 ± 15.9 years; mean body mass index [BMI] 25.9 ± 4.8 kg/m2). Successful DFT with the first ICD shock was observed in 264 patients (66.3%). One hundred fourteen patients were defibrillated with the second (n = 104) or third (n = 10) DFT after changing shock polarity and/or shock energy. Overall, 20 patients needed at least 3 DFT (ie, 80 J and/or re-positioning). The majority (n = 88 [65.7%]) of DFT failures occurred before 2015 with the first-generation S-ICD. PRAETORIAN score was an independent predictor of DFT failure (odds ratio [OR] 1.007; 95% confidence interval [CI] 1.003-1.011 P ≤.001), while whereas BMI alone was not (P = .31). Presence of hypertrophic cardiomyopathy (HCM) (OR 2.6; 95% CI 1.3-4.4; P = .004) was predictive for at least 1 unsuccessful DFT in our multivariate regression analysis. CONCLUSION: PRAETORIAN score proved to be a useful and valid predictive tool for successful DFT, whereas BMI only had a limited role. Patients with HCM were at increased risk for DFT failure or needed higher DFT energy.

Major in-hospital complications after catheter ablation of cardiac arrhythmias: individual case analysis of 43 031 procedures.

AIMS: In-hospital complications of catheter ablation for atrial fibrillation (AF), atrial flutter (AFL), and ventricular tachycardia (VT) may be overestimated by analyses of administrative data. METHODS AND RESULTS: We determined the incidences of in-hospital mortality, major bleeding, and stroke around AF, AFL, and VT ablations in four German tertiary centres between 2005 and 2020. All cases were coded by the G-DRG- and OPS-systems. Uniform code search terms were applied defining both the types of ablations for AF, AFL, and VT and the occurrence of major adverse events including femoral vascular complications, iatrogenic tamponade, stroke, and in-hospital death. Importantly, all complications were individually reviewed based on patient-level source records. Overall, 43 031 ablations were analysed (30 361 AF; 9364 AFL; 3306 VT). The number of ablations/year more than doubled from 2005 (n = 1569) to 2020 (n = 3317) with 3 times and 2.5 times more AF and VT ablations in 2020 (n = 2404 and n = 301, respectively) as compared to 2005 (n = 817 and n = 120, respectively), but a rather stable number of AFL ablations (n = 554 vs. n = 612). Major peri-procedural complications occurred in 594 (1.4%) patients. Complication rates were 1.1% (n = 325) for AF, 1.0% (n = 95) for AFL, and 5.3% (n = 175) for VT. With an increase in complex AF/VT procedures, the overall complication rate significantly increased (0.76% in 2005 vs. 1.81% in 2020; P = 0.004); but remained low over time. Following patient-adjudication, all in-hospital cardiac tamponades (0.7%) and strokes (0.2%) were related to ablation. Major femoral vascular complications requiring surgical intervention occurred in 0.4% of all patients. The in-hospital mortality rate adjudicated to be ablation-related was lower than the coded mortality rate: AF: 0.03% vs. 0.04%; AFL: 0.04% vs. 0.14%; VT: 0.42% vs. 1.48%. CONCLUSION: Major adverse events are low and comparable after catheter ablation for AFL and AF (∼1.0%), whereas they are five times higher for VT ablations. In the presence of an increase in complex ablation procedures, a moderate but significant increase in overall complications from 2005-20 was observed. Individual case analysis demonstrated a lower than coded ablation-related in-hospital mortality. This highlights the importance of individual case adjudication when analysing administrative data.

Temperature to time Catch-Up: a novel procedural endpoint to predict durable pulmonary vein isolation after cryoballoon ablation of paroxysmal atrial fibrillation.

BACKGROUND: Cryoballoon ablation is a widely used single-shot technique for pulmonary vein isolation (PVI) in the treatment of paroxysmal atrial fibrillation (AF). Procedural endpoints ensuring maximal PVI durability are important. OBJECTIVE: To assess the performance of cryoablation procedural markers to predict long-term PVI. METHODS: In a single center, consecutive patients who underwent redo ablation with high-density mapping for symptomatic AF recurrence after cryoballoon ablation were included and cryoballoon procedural data were collected, including temperature values at 30 and 60 s, time to isolation, nadir temperature and the velocity of temperature decline estimated with the temperature/time catch-up point (T2T-Catch-Up) defined as positive when the freeze temperature in minus degree equals the time in seconds after cryoablation initiation (e.g. - 15 °C in the first 15 s of the ablation impulse). RESULTS: 47 patients (62% male; 58.3 ± 11.2 years) were included. Overall, 38 (80.9%) patients had ≥ 1 reconnected PV. Among 186 PVs, 56 (30.1%; 1.2 per patient on average) were reconnected. Univariate analysis revealed T2T-Catch-Up in 103 (56%) and more frequent in durably isolated than in reconnected PVs (93 [72%] vs 10 [19%], p < 0.0001). Among binary endpoints, T2T-Catch-Up had the highest specificity (82%) and predictive value for durable PVI at redo ablation (90%). In multivariable analyses, absence of T2T-Catch-Up (Odds-ratio 0.12, 95% CI [0.05-0.31], p < 0.0001) and right superior PV (Odds-ratio 3.14, 95% CI [1.27-7.74], p = 0.01) were the only variables independently associated with PV reconnection. CONCLUSION: T2T-Catch-Up, a new and simple cryoballoon procedural endpoint demonstrated excellent predictive value and strong statistical association with durable PVI.

Ventricular arrhythmia burden in ICD patients during the second wave of the COVID-19 pandemic.

AIM: COVID-19 has been associated with cardiovascular complications including ventricular arrhythmias (VA) and an increased number of out-of-hospital cardiac arrests. Nevertheless, several authors described a decrease of VA burden in patients with an implantable defibrillator (ICD) during the first wave of the COVID-19 pandemic. The objective of this study was to determine if these observations could be transferred to later periods of the pandemic as well. METHODS: We retrospectively analyzed a total of 1674 patients with an ICD presenting in our outpatient clinic during the second wave of the COVID-19 pandemic and during a control period for the occurrence of VA requiring ICD interventions. RESULTS: Seven hundred ninety-five patients with an ICD had a device interrogation in our ambulatory clinic during the second wave of the COVID-19 pandemic compared to eight hundred seventy-nine patients in the control period. There was significant higher amount of adequate ICD therapies in the course of the COVID-19 period. Thirty-six patients (4.5%) received in total eighty-five appropriate ICD interventions during COVID-19, whereas only sixteen patients (1.8%) had sustained VA in the control period (p = 0.01). CONCLUSION: In contrast to the first wave of COVID-19, which was characterized by a decrease or least stable number of ICD therapies in several centers, we found a significant increase of VA in ICD patients during the second wave of COVID-19. Possible explanations for this observation include higher infectious rates, potential cardiac side effects of the vaccination as well as personal behavioral changes, or reduced utilization of medical services.

Predictors for major in-hospital complications after catheter ablation of ventricular arrhythmias: validation and modification of the Risk in Ventricular Ablation (RIVA) Score.

OBJECTIVE AND BACKGROUND: Catheter-based treatment of patients with ventricular arrhythmias (VA) reduces VA and mortality in selected patients. With regard to potential risks of catheter ablation, a benefit-risk assessment should be carried out. This can be performed with risk scores such as the recently published "Risk in Ventricular Ablation (RIVA) Score". We sought to validate this score and to test for possible additional predictors in a large database of VT ablations. METHODS AND RESULTS: We analyzed 1964 catheter ablations for VA in patients with (1069; 54.4%) and without (893, 45.6%) structural heart disease (SHD) and observed an overall major adverse event rate of 4.0% with an in-hospital mortality of 1.3% with significantly less complications occurring in patients without structural heart disease (6.5% vs. 1.1%; p ≤ 0.01). The RIVA Score demonstrated to be a valid predictive tool for major in-hospital complications (OR 1.18; 95% CI 1.12, 1.25; p ≤ 0.001). NYHA Class ≥ III (OR 2.5; 95% CI 1.5, 4.2; p < 0.001) and age (OR 1.04; 95% CI 1.02, 1.07; p ≤ 0.001) proved to be additional predictive parameters. Hence, a modified RIVA Score (mRIVA) model was analyzed with a subset of established predictors (SHD, eGFR, epicardial puncture) as well as new predictive parameters (age, NYHA Class ≥ III), that achieved a higher predictive value for major complications compared with the model based on all RIVA variables. CONCLUSION: Adding age and functional heart failure status (NYHA class) as simple clinical parameters to the recently published RIVA Score increases the predictive value for ablation-associated complications in a large VT ablations registry.

The Necessity of Multiple Data Sources for ECG-Based Machine Learning Models.

Even though the interest in machine learning studies is growing significantly, especially in medicine, the imbalance between study results and clinical relevance is more pronounced than ever. The reasons for this include data quality and interoperability issues. Hence, we aimed at examining site- and study-specific differences in publicly available standard electrocardiogram (ECG) datasets, which in theory should be interoperable by consistent 12-lead definition, sampling rate, and measurement duration. The focus lies upon the question of whether even slight study peculiarities can affect the stability of trained machine learning models. To this end, the performances of modern network architectures as well as unsupervised pattern detection algorithms are investigated across different datasets. Overall, this is intended to examine the generalization of machine learning results of single-site ECG studies.

In-hospital mortality and major complications related to radiofrequency catheter ablations of over 10 000 supraventricular arrhythmias from 2005 to 2020: individualized case analysis of multicentric administrative data.

AIMS: The incidence of in-hospital post-interventional complications and mortality after ablation of supraventricular tachycardia (SVT) vary among the type of procedure and most likely the experience of the centre. As ablation therapy of SVT is progressively being established as first-line therapy, further assessment of post-procedural complication rates is crucial for health care quality. METHODS AND RESULTS: We aimed at determining the incidence of in-hospital mortality and bleeding complications from SVT ablations in German high-volume electrophysiological centres between 2005 and 2020. All cases were registered by the German Diagnosis Related Groups-and the German Operation and Procedure Classification (OPS) system. A uniform search for SVT ablations from 2005 to 2020 with the same OPS codes defining the type of ablation/arrhythmia as well as the presence of a vascular complication, cardiac tamponade, and/or in-hospital death was performed. An overall of 47 610 ablations with 10 037 SVT ablations were registered from 2005 to 2020 among three high-volume centres. An overall complication rate of 0.5% (n = 38) was found [median age, 64; ±15 years; female n = 26 (68%)]. All-cause mortality was 0.02% (n = 2) and both patients had major prior co-morbidities precipitating a lethal outcome irrespective of the ablation procedure. Vascular complications occurred in 10 patients (0.1%), and cardiac tamponade was detected in 26 cases (0.3%). CONCLUSION: The present case-based analysis shows an overall low incidence of in-hospital complications after SVT ablation highlighting the overall very good safety profile of SVT ablations in high-volume centres. Further prospective analysis is still warranted to guarantee continuous quality control and optimal patient care.

10-year follow-up of interventional electrophysiology: updated German survey during the COVID-19 pandemic.

INTRODUCTION: This study provides an update of survey-based data providing an overview of interventional electrophysiology over the last decade. Overall infrastructure, procedures, and training opportunities in Germany were assessed. METHODS: By analyzing mandatory quality reports, German cardiology centres performing electrophysiological studies were identified to repeat a questionnaire from 2010 and 2015. RESULTS: A complete questionnaire was returned by 192 centers performing about 75% of all ablations in Germany in 2020. In the presence of the COVID-19 pandemic, a total of 76.304 procedures including 68.407 ablations were reported representing a 38% increase compared to 2015. The median number of ablations increased from 180 in 2010 to 377 in 2020. AF was the most common arrhythmia ablated (51 vs. 35% in 2010). PVI with radiofrequency point-by-point ablation (64%) and cryo-balloon ablation (34%) were the preferred strategies. Less than 50 (75) PVI were performed by 31% (36%) of all centres. Only 25 and 24% of participating centres fulfilled EHRA and national requirements for training centre accreditation, respectively. There was a high number of EP centres with no fellows (38%). The proportion of female fellows in EP increased from 26% in 2010 to 33% in 2020. CONCLUSION: Comparing 2020, 2010 and 2015, an increasing number of EP centres and procedures were registered. In 2020, more than every second ablation was for therapy of AF. In the presence of an increasing number of procedures, training opportunities were still limited, and most centres did not fulfill recommended EHRA or national requirements for accreditation.

The Impact of Cardiac Devices on Patients' Quality of Life-A Systematic Review and Meta-Analysis.

The implantation of cardiac devices significantly reduces morbidity and mortality in patients with cardiac arrhythmias. Arrhythmias as well as therapy delivered by the device may impact quality of life of patients concerned considerably. Therefore we aimed at conducting a systematic search and meta-analysis of trials examining the impact of the implantation of cardiac devices, namely implantable cardioverter-defibrillators (ICD), pacemakers and left-ventricular assist devices (LVAD) on quality of life. After pre-registering the trial with the PROSPERO database, we searched Medline, PsycINFO, Web of Science and the Cochrane databases for relevant publications. Study quality was assessed by two independent reviewers using standardized protocols. A total of 37 trials met our inclusion criteria. Of these, 31 trials were cohort trials while 6 trials used a randomized controlled design. We found large pre-post effect sizes for positive associations between quality of life and all types of devices. The effect sizes for LVAD, pacemaker and ICD patients were g = 1.64, g = 1.32 and g = 0.64, respectively. There was a lack of trials examining the effect of implantation on quality of life relative to control conditions. Trials assessing quality of life in patients with cardiac devices are still scarce. Yet, the existing data suggest beneficial effects of cardiac devices on quality of life. We recommend that clinical trials on cardiac devices routinely assess quality of life or other parameters of psychological well-being as a decisive study endpoint. Furthermore, improvements in psychological well-being should influence decisions about implantations of cardiac devices and be part of patient education and may impact shared decision-making.

[Electromagnetic interference in 3D-mapping procedures]. / Elektromagnetische Interferenzen bei 3-D-Mappingverfahren.

Catheter-based ablation is nowadays a safe and widespread procedure for the treatment of cardiac arrhythmia. This requires exact anatomical knowledge both before and during the examination and is an important prerequisite for targeted treatment. At the beginning of the era of interventional catheter-based treatment, fluoroscopy was the only and usual means of visualization, whereas in the middle of the 1990s continuous 3D-mapping systems were developed for the non-fluoroscopic examination of patients. The correct use of these 3­D systems, which non-fluoroscopically visualize the catheter and mostly identify mechanisms of arrhythmia in great detail, nowadays makes an important contribution to successful interventional catheter treatment of arrhythmia; however, it is not uncommon for patients with ventricular arrhythmia to also carry implanted electronic devices, such as pacemakers, defibrillators or less frequently left ventricular hemodynamic support systems. All implantable devices lead to electromagnetic interferences, which can complicate the diagnostics and treatment during electrophysiological examinations and ablation. This article addresses the adversities and experiences associated with magnet-based 3D systems and implantable electromagnetically active cardiac devices.

Detection of Patients with Congenital and Often Concealed Long-QT Syndrome by Novel Deep Learning Models.

INTRODUCTION: The long-QT syndrome (LQTS) is the most common ion channelopathy, typically presenting with a prolonged QT interval and clinical symptoms such as syncope or sudden cardiac death. Patients may present with a concealed phenotype making the diagnosis challenging. Correctly diagnosing at-risk patients is pivotal to starting early preventive treatment. OBJECTIVE: Identification of congenital and often concealed LQTS by utilizing novel deep learning network architectures, which are specifically designed for multichannel time series and therefore particularly suitable for ECG data. DESIGN AND RESULTS: A retrospective artificial intelligence (AI)-based analysis was performed using a 12-lead ECG of genetically confirmed LQTS (n = 124), including 41 patients with a concealed LQTS (33%), and validated against a control cohort (n = 161 of patients) without known LQTS or without QT-prolonging drug treatment but any other cardiovascular disease. The performance of a fully convolutional network (FCN) used in prior studies was compared with a different, novel convolutional neural network model (XceptionTime). We found that the XceptionTime model was able to achieve a higher balanced accuracy score (91.8%) than the associated FCN metric (83.6%), indicating improved prediction possibilities of novel AI architectures. The predictive accuracy prevailed independently of age and QTc parameters. CONCLUSIONS: In this study, the XceptionTime model outperformed the FCN model for LQTS patients with even better results than in prior studies. Even when a patient cohort with cardiovascular comorbidities is used. AI-based ECG analysis is a promising step for correct LQTS patient identification, especially if common diagnostic measures might be misleading.

Machine learning in the detection and management of atrial fibrillation.

Machine learning has immense novel but also disruptive potential for medicine. Numerous applications have already been suggested and evaluated concerning cardiovascular diseases. One important aspect is the detection and management of potentially thrombogenic arrhythmias such as atrial fibrillation. While atrial fibrillation is the most common arrhythmia with a lifetime risk of one in three persons and an increased risk of thromboembolic complications such as stroke, many atrial fibrillation episodes are asymptomatic and a first diagnosis is oftentimes only reached after an embolic event. Therefore, screening for atrial fibrillation represents an important part of clinical practice. Novel technologies such as machine learning have the potential to substantially improve patient care and clinical outcomes. Additionally, machine learning applications may aid cardiologists in the management of patients with already diagnosed atrial fibrillation, for example, by identifying patients at a high risk of recurrence after catheter ablation. We summarize the current state of evidence concerning machine learning and, in particular, artificial neural networks in the detection and management of atrial fibrillation and describe possible future areas of development as well as pitfalls. Typical data flow in machine learning applications for atrial fibrillation detection.

Lyme carditis manifesting with sinoatrial exit block: a case report.

BACKGROUND: Lyme disease is the most common vector-borne disease in North America and Europe. Infection with the spirochete Borrelia burgdorferi complex can involve cardiac tissue causing Lyme carditis (LC). Due to the infection of conductive tissue, LC typically presents with varying degrees of atrioventricular conduction block. Here, we provide the first evidence that conductive tissue of the sinus node can be involved in LC resulting in higher degree sinoatrial (SA) block with concomitant syncope. CASE SUMMARY: We report the case of an otherwise healthy 31-year-old female presenting with LC manifesting with SA exit block causing asystole over 12 s with concomitant syncope. Signs of SA block completely resolved with antibiotic treatment with a third-generation cephalosporin. The patient did not require permanent pacemaker implantation and had no sinus pauses after 12 months of follow-up as confirmed via implantable loop recorder. CONCLUSION: The possibility of LC in patients with sinus node dysfunction should be considered, as adequate antibiotic therapy can spare patients from potentially unnecessary pacemaker implantation.

[New developments in leadless pacing systems]. / Neue Entwicklungen bei kabellosen Schrittmachersystemen.

Leadless pacing systems, especially the Micra™ TPS system, deliver an effective and safe alternative to the previous conventional transvenous systems in patients with impossible transvenous access and seem to be compatible with other implantable devices (S-ICD, deep brain stimulators) with no limitations in efficacy or safety. Also, new outlooks on leadless resynchronization therapy seem promising and could prevent future patients from lead- or operation-associated complications. Current limits to the implementation in everyday clinical practice are mostly the unavailability of the devices or cost issues through lack of health insurance reimbursement. However, more promising data through further studies and rising implantation rates are expected based on the positive current clinical data.

Bullet-associated ventricular tachycardia: a case report.

BACKGROUND: The majority of ventricular tachycardias (VTs) occurs in patients with structural heart disease and is associated with an increased risk of sudden cardiac death. These VT are scar-related and may develop in patients with ischaemic or non-ischaemic cardiomyopathies. CASE SUMMARY: We describe a 44-year-old patient without any pre-existing cardiovascular disease, presenting with the first documentation of a haemodynamically unstable sustained fast VT with a cycle length of 250 ms. He reported a suicidal attempt with a self-made handgun aged 16 when he had shot himself in the thorax and had injured the myocardium. After presenting with the VT coronary artery disease was excluded through cardiac catheterization. A cardiovascular magnetic resonance study showed a localized myocardial scar in the left ventricular free wall starting from the subepicardium and correlating to the scar described 28 years ago by the thoracic surgeons. In an electrophysiological study, non-sustained VT were easily inducible. Presuming a causal relationship between the fast VT and the epicardial scar, a single-chamber implantable cardioverter-defibrillator was implanted and beta-blocker therapy was initiated. DISCUSSION: Scar-related VT often occur many years after an acute event, e.g. an acute myocardial infarction. This case highlights, that any cardiac trauma, even a superficial epicardial projectile-related damage with subsequent scarring, may cause a VT after many years and to our knowledge for the first time describes the occurrence of a VT due to mechanical damage to the myocardium by a gunshot.