Diagnosis Of Tachycardia Research Articles

Development and implementation of a guideline-based decision support system for etiological diagnosis of Sustained Monomorphic Ventricular Tachycardia (SMVT)

Abstract Background Guideline (GL)-based decision support systems (DSSs) play a significant role in supporting physicians in their decision-making processes by providing structured clinical guidance. While these systems have shown significant success in enhancing practitioner performance and patient outcomes in general practice, their application in the context of ventricular arrhythmias remains limited. Moreover, the clinical etiological diagnosis of ventricular arrhythmias presents various challenges for healthcare professionals, such as adherence to updated diagnostic criteria and understanding of complex arrhythmia mechanisms. Purpose In this study, we aim to design, implement, and evaluate a guideline-based decision support systems for etiological diagnosis of sustained monomorphic ventricular tachycardia (SMVT), which could potentially address critical challenges associated with the disease diagnosis and management. Methods To comprehensively capture the semantics embedded in clinical guidelines, we first developed a dedicated knowledge graph tailored to the clinical decision-making. This involved extracting entities and relationships pertinent to key decision procedures from ESC guidelines for ventricular arrhythmias, clinical textbooks or literatures. Subsequently, we translated instances within the knowledge graph into archetypes within openEHR, amplifying the interoperability of clinical information. To enhance the interpretability of the DSS, we established executable diagnostic and treatment processes to offer visual representation of clinical steps in diagnosis and treatment. Ultimately, we constructed a decision support engine to implement the GL-DSS, and its effectiveness was evaluated with anonymous real-world data. Results The proposed GL-DSS was found to be quite feasible and could provide etiological diagnosis for SMVT. The knowledge base for the constructed GL-DDS included more than 2000 entities and relations, which played a vital role in representing disease pathogenesis. The proposed system can map the clinical entities to a set of openEHR archetypes, thus mitigate the interoperability issues of the hospital information systems and CDSS data integration. Also, this module improved system usability and ensured that guidelines could be easily translated and updated into decision support tools. Real-word medical records from 20 patient were collected for model evaluation, the results showed that the GL-DSS covered most of the entities and relations between diseases and diagnostic evidence recorded in clinical texts and achieved a diagnosis accuracy of 80%. Conclusions The results demonstrated that our proposed GL-DSS could completely and accurately capture the diagnostic information under the concrete EHR data. Thus, the implement decision support system could have the potential to improve clinical decision-making, patient care, and outcomes in this specialized medical domain.

Implications of age and sex on the diagnostic yield of sudden arrhythmic death syndrome

Abstract Introduction Sudden arrhythmic death syndrome (SADS) refers to an unexplained sudden death with a negative autopsy. An inherited cardiac condition (ICC) may be diagnosed through familial clinical evaluation (FE) or post-mortem genetic testing (molecular autopsy [MA]) or both. We aimed to investigate the impact of age and sex of SADS decedents on the diagnostic yield and aetiology to facilitate a targeted approach to management. Methods Consecutive referrals to a single centre for FE only, MA only or both, following a SADS death were included. First-degree family members underwent comprehensive FE. A panel of 36 cardiac genes was sequenced for MA. A post-mortem diagnosis could be obtained by either FE, MA or both. A Bayesian framework for analysis was performed to identify associations. Results Seven-hundred-and-sixty SADS decedents (66% male; mean age 31±12 years) were investigated. The overall diagnostic yield for an ICC was 37% (32-42%) and 9% (6-12%) for FE and MA cohorts, respectively. In a subset where both MA and FE were performed the diagnostic yield was 45% (38-61%). For each year increase in age, the relative risk of an FE diagnosis of long QT syndrome (LQTS) or Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) versus remaining unexplained declined by 5.6% (RR 0.94 [0.91-0.98]) and by 11% (RR 0.89 [0.81-0.97]), respectively. Females were more likely to have a diagnosis compared with males by both FE (40% [34-45%] vs 36% [31-41%]) and MA (15% [10-21%] vs 6% [3-8%]). Females (8.1% [4.1-13.4%)], were more likely to be diagnosed with LQTS than males (1.2% [0.2-2.7%]) in the MA cohort. Conclusions After a SADS death, the diagnostic yield of comprehensive FE, MA or both in an expert setting can be up to 45%. Younger age of death is associated with greater likelihood of LQTS and CPVT diagnosis with the highest yield in children and adolescents. Female sex in SADS decedents is associated with a higher yield of LQTS in MA. These data highlight the relative utility of FE and MA depending on age and sex for determining underlying diagnoses following SADS deaths.

Interpretable Clinical Decision-Making Application for Etiological Diagnosis of Ventricular Tachycardia Based on Machine Learning.

Background: Ventricular tachycardia (VT) can broadly be categorised into ischemic heart disease, non-ischemic structural heart disease, and idiopathic VT. There are few studies related to the application of machine learning for the etiological diagnosis of VT, and the interpretable methods are still in the exploratory stage for clinical decision-making applications. Objectives: The aim is to propose a machine learning model for the etiological diagnosis of VT. Interpretable results based on models are compared with expert knowledge, and interpretable evaluation protocols for clinical decision-making applications are developed. Methods: A total of 1305 VT patient data from 1 January 2013 to 1 September 2023 at the Arrhythmia Centre of Fuwai Hospital were included in the study. Clinical data collected during hospitalisation included demographics, medical history, vital signs, echocardiographic results, and laboratory test outcomes. Results: The XGBoost model demonstrated the best performance in VT etiological diagnosis (precision, recall, and F1 were 88.4%, 88.5%, and 88.4%, respectively). A total of four interpretable machine learning methods applicable to clinical decision-making were evaluated in terms of visualisation, clinical usability, clinical applicability, and efficiency with expert knowledge interpretation. Conclusions: The XGBoost model demonstrated superior performance in the etiological diagnosis of VT, and SHAP and decision tree interpretable methods are more favoured by clinicians for decision-making.

Differential diagnosis of tachycardias with wide QRS complexes

Differential diagnosis of tachycardias with wide QRS complexes

Study on the feasibility of distinguishing ventricular and pre-excited arrhythmia rhythms by a new algorithm

BackgroundThe differentiation and diagnosis of ventricular tachycardia (VT) and pre-excited tachycardia (PXT) remains a challenging task, especially when typical AV dissociation is not present. The purpose of this article is to study the feasibility of a new theoretical algorithm for identifying ventricular arrhythmias (VA) and pre-excited arrhythmias (PA) rhythms (which can be used to distinguish VT from PXT, etc.). MethodThis study involved the deduction of a new algorithm by combining knowledge of cardiac anatomy, vectorcardiography, and cardiac electrophysiology. The new algorithm evaluated the diagnostic value through intracardiac electrophysiology in 205 cases of VA and PA. The new algorithm diagnoses VA based on the following 4-step process:1.The QRS complex in leads II, III, and aVF shows a unidirectional R wave, and lead aVR shows a QS pattern.2.S waves are predominant in two or more of leads I, aVF, and V6.3.Lead V2 shows ≥3 phase waves or returning branch notching (note: returning branch refers to the band of QRS complexes returning to the baseline).4.Lead V5 shows a negative wave in the initial portion or returning branch notching.If none of these criteria are met, the diagnosis is PA. The diagnostic value of the new algorithm is compared with the Steurer algorithm and the Vereckei algorithm (diagnosed based on the QRS waveform characteristics of the two algorithms during electrophysiological verification, excluding the diagnosis of atrioventricular dissociation). ResultsThe new algorithm showed significant advantages in terms of AUC value (0.83 vs. 0.61 vs. 0.57), sensitivity (83.6 % vs. 23.3 % vs. 24.8 %), and accuracy (82.9 % vs. 48.3 % vs. 46.3 %) compared to the Steurer algorithm and Vereckei algorithm based on QRS waveform characteristics for diagnosing VA (137 cases) and PA (68 cases). This indicates that the new algorithm is more accurate in identifying idiopathic VA. While there was a significant difference in specificity between the New algorithm and Steurer algorithm (82.3 % vs. 98.5 %, p < 0.05), the difference with Vereckei algorithm (82.3 % vs. 89.7 %) was not significant.In the New algorithm, the sensitivity and specificity for each step are as follows:-Step 1: Sensitivity 34.3 %, Specificity 94.1 %.-Step 2: Sensitivity 24.1 %, Specificity 98.5 %.-Step 3: Sensitivity 18.3 %, Specificity 100 %.-Step 4: Sensitivity 6.6 %, Specificity 89.7 %.Step 1 had the highest AUC value, indicating the best overall diagnostic performance among all steps. Step 2 and Step 3 also performed well, while Step 4 had relatively poorer diagnostic performance. ConclusionThe new algorithm is suitable for identifying the origin of VA and PA rhythms.

Supraventricular tachycardia diagnosis in asthma patients is associated with adverse health outcomes.

Supraventricular tachycardia (SVT) can occur during treatment of an acute asthma exacerbation. There are, however, no data on the long-term outcomes of children who are diagnosed with both asthma and SVT. This study aims to analyze the impact of SVT in asthmatic children on mortality and/or cardiac arrest, hypothesizing asthmatic subjects with SVT have increased mortality and/or cardiac arrest compared to asthmatic subject with no-SVT. This was a retrospective cohort study, utilizing the TriNetX© electronic health record (EHR) database that included asthmatic subjects 2-18 years of age. The study population was divided into two groups (subjects with SVT diagnosis and no-SVT diagnosis). Data related to demographics, diagnostic, procedural, and medication codes were collected. The primary outcome was any death and/or cardiac arrest in a patient after the first asthma diagnosis date. This study included 91,066 asthmatic subjects (244 [0.27%] with SVT and 90,822 [99.73%] with no-SVT). Multivariable logistic regression analysis demonstrated that after controlling for demographic and clinical features, the odds of all-cause death and/or cardiac arrest after the first reported asthma exacerbation was significantly higher in asthmatic children with SVT compared to no-SVT (odds ratio [OR]: 4.30, confidence interval [CI]: 2.50-7.39, p < .001). Our large nationwide EHR study suggests that asthmatic pediatric patients with documented SVT diagnosis at any point in their EHR may be at increased risk of adverse health outcomes compared to no-SVT. Further studies are needed to determine the factors contributing to the increased risk of mortality and/or cardiac arrest in children with asthma and SVT.

The Diagnostic Utility of Holter Monitoring in Catecholaminergic Polymorphic Ventricular Tachycardia.

Holter monitoring may raise suspicion of an underlying catecholaminergic polymorphic ventricular tachycardia (CPVT) diagnosis. Although not a primary investigation for CPVT, Holter monitoring is ubiquitously used as a diagnostic tool in the heart rhythm clinic. The objective of this study was to explore Holter monitoring in CPVT diagnosis. This retrospective cohort study analyzed off-therapy Holter monitoring from 13 ryanodine receptor 2-positive CPVT and 34 healthy patients from the Canadian Hearts in Rhythm Organization national registry. Using the Edwards method, the ratio of ambient-maximum heart rate during Holter monitoring was correlated with exertion level to separate premature ventricular contractions (PVCs) during periods of adrenergic and nonadrenergic stress. A receiver operating characteristic curve analysis determined the optimal threshold for isolating CPVT-induced PVCs during adrenergic states. PVC burden differed between groups (P=0.001) but was within population norm, suggesting ambient PVCs are uncommon in CPVT. CPVT patients had higher PVC counts than healthy controls (P=0.002), with a different distribution based on adrenergic state. The optimal threshold for separating PVCs into periods of adrenergic and nonadrenergic stress in CPVT patients was 76% of the maximum heart rate during the monitoring period. Compared with healthy controls, CPVT patients had a higher PVC count, limited to periods of adrenergic stress, defined by >76% maximum heart rate threshold (P=0.002; area under the receiver operating characteristic curve: 0.84). Below this threshold, there was no significant PVC difference (P=0.604). Holter monitor PVC counts alone are inadequate for CPVT diagnosis, owing to the adrenergic nature of the disease. Quantifying PVC prevalence at a heart rate threshold >76% identified CPVT with moderate sensitivity (69%) and high specificity (94%).

Frequency of Atypical AVNRT in Patients Presenting with Narrow Complex Tachycardia

ABSTRACT Objective: To determine the frequency of atypical AVNRT in patients presenting with Narrow Complex Tachycardia. Study Design: Descriptive Cross Sectional Place and Duration of Study: Department of Cardiology, MTI-Hayatabad Medical Complex, Peshawar, from March, 2021 to March, 2022. Methodology: Ninety-three patients of either aged 30 to 80 years diagnosed with narrow complex tachycardia by consultant cardiac electrophysiologist on ECG showing QRS duration of less than 120 milliseconds were included in this study. Patients were managed as per standard protocol which included comprehensive clinical evaluation such as patient history, physical examination and invasive electrophysiological study for the diagnosis and characterization of atypical Atrioventricular Nodal Reentrant Tachycardia (AVNRT). Results: A total of ninety-three patients were studied with mean age of 43.08 years (SD = 9.07). Among the participants, 58.1% were male, while 41.9% were female. Majority of patients had Slow-Fast AVNRT (7.5%) followed by Fast-Slow AVNRT (3.2%), and Slow-Slow AVNRT in 2.2% patients. Conclusion: This study underscored the importance of gender-specific variations in the prevalence of different AVNRT types and highlighted the impact of gender as a potential influencing factor in the manifestation of specific types of AVNRT within the study population.

Disparities in the implantation of secondary prevention implantable cardioverter defibrillator in the United States.

The annual incidence of sudden cardiac death is over 300,000 in the United States (US). Historically, inpatient implantation of secondary prevention implantable cardioverter defibrillator (ICD) has been variable and subject to healthcare disparities. To evaluate contemporary practice trends of inpatient secondary prevention ICD implants within the US on the basis of race, sex, and socioeconomic status (SES). The study is a retrospective analysis of the National Inpatient Sample from 2016 to 2020 of adult discharges with a primary diagnosis of ventricular tachycardia (VT), ventricular flutter, and fibrillation (VF). Adjusted ICD implantation rates based on race, sex, and SES and associated temporal trends were calculated using multivariate regression. A total of 193,600 primary VT/VF discharges in the NIS were included in the cohort, of which 57,895 (29.9%) had ICD placement. There was a significant racial and ethnic disparity in ICD placement for Black, Hispanic, Asian, and Native American patients as compared to White patients; adjusted odds ratio (aOR): 0.86 [p<.01], 0.90 [p = .03], 0.81[p<.01], 0.45 [p<.01], respectively. Female patients were also less likely to receive an ICD compared to male patients (aOR: 0.75, p<.01). Disparities in ICD placement remained stable over the study period (ptrend ≥.05 in all races, both sexes and income categories). Racial, sex, and SES disparities persisted for secondary prevention ICD implants in the US. An investigation into contributing factors and subsequent approaches are needed to address the modifiable causes of disparities in ICD implantation as these trends have not improved compared to historic data.

A Single Atrial Extrastimulation Resetting His Bundle During Supraventricular Tachycardia to Differentiate Atrial Tachycardia

BackgroundCatheter ablation is the curative treatment for paroxysmal supraventricular tachycardia (SVT). However, atrial tachycardia (AT) diagnosis is often challenging, especially when SVT is terminated by pacing. ObjectivesThis study sought to develop a novel method for AT diagnosis. MethodsA total of 147 SVTs including 28 ATs, 87 atrioventricular nodal re-entrant tachycardias, and 32 orthodromic reciprocating tachycardias were prospectively studied. Single atrial extrastimulation was performed at the proximal coronary sinus from a coupling interval 20 milliseconds shorter than the tachycardia cycle length and gradually decreased until the His bundle (HB) was first reset and further until the SVT was terminated. The response of the SVT during the first HB resetting and the termination pattern were examined. ResultsIn 27 of 28 ATs, tachycardia was unaffected when HB resetting whereas, in atrioventricular nodal re-entrant tachycardias or orthodromic reciprocating tachycardias (non-AT), tachycardia was simultaneously reset when HB resetting or was terminated with an atrio-Hisian block. When the coupling interval was further shortened for cases in which tachycardia persisted, all 33 SVTs with tachycardia termination with atrio-Hisian block were non-ATs, whereas 5 ATs and 7 non-ATs were terminated with Hisian-atrial block. The sensitivity, specificity, and positive and negative predictive values of the pattern of tachycardia that was unaffected when HB resetting for AT diagnosis were 96%, 100%, 100%, and 99%, respectively. Those of the pattern of tachycardia termination with atrio-Hisian block for non-AT diagnosis were 92%, 100%, 100%, and 42%, respectively. ConclusionsSingle atrial extrastimulation from the proximal coronary sinus during tachycardia was useful and effective for AT diagnosis.

Clinical Decision Support Requirements for Ventricular Tachycardia Diagnosis Within the Frameworks of Knowledge and Practice: Survey Study.

Ventricular tachycardia (VT) diagnosis is challenging due to the similarity between VT and some forms of supraventricular tachycardia, complexity of clinical manifestations, heterogeneity of underlying diseases, and potential for life-threatening hemodynamic instability. Clinical decision support systems (CDSSs) have emerged as promising tools to augment the diagnostic capabilities of cardiologists. However, a requirements analysis is acknowledged to be vital for the success of a CDSS, especially for complex clinical tasks such as VT diagnosis. The aims of this study were to analyze the requirements for a VT diagnosis CDSS within the frameworks of knowledge and practice and to determine the clinical decision support (CDS) needs. Our multidisciplinary team first conducted semistructured interviews with seven cardiologists related to the clinical challenges of VT and expected decision support. A questionnaire was designed by the multidisciplinary team based on the results of interviews. The questionnaire was divided into four sections: demographic information, knowledge assessment, practice assessment, and CDS needs. The practice section consisted of two simulated cases for a total score of 10 marks. Online questionnaires were disseminated to registered cardiologists across China from December 2022 to February 2023. The scores for the practice section were summarized as continuous variables, using the mean, median, and range. The knowledge and CDS needs sections were assessed using a 4-point Likert scale without a neutral option. Kruskal-Wallis tests were performed to investigate the relationship between scores and practice years or specialty. Of the 687 cardiologists who completed the questionnaire, 567 responses were eligible for further analysis. The results of the knowledge assessment showed that 383 cardiologists (68%) lacked knowledge in diagnostic evaluation. The overall average score of the practice assessment was 6.11 (SD 0.55); the etiological diagnosis section had the highest overall scores (mean 6.74, SD 1.75), whereas the diagnostic evaluation section had the lowest scores (mean 5.78, SD 1.19). A majority of cardiologists (344/567, 60.7%) reported the need for a CDSS. There was a significant difference in practice competency scores between general cardiologists and arrhythmia specialists (P=.02). There was a notable deficiency in the knowledge and practice of VT among Chinese cardiologists. Specific knowledge and practice support requirements were identified, which provide a foundation for further development and optimization of a CDSS. Moreover, it is important to consider clinicians' specialization levels and years of practice for effective and personalized support.

Cannon A wave validation as a diagnostic tool in paroxysmal supraventricular tachycardias.

The presence of cannon A waves, the so called "frog sign", has traditionally been considered diagnostic of atrioventricular nodal re-entrant tachycardia (AVNRT). Nevertheless, it has never been systematically evaluated. The aim of this study is to assess the independent diagnostic utility of cannon A waves in the differential diagnosis of supraventricular tachycardias (SVTs). We prospectively included 100 patients who underwent an electrophysiology (EP) study for SVT. The right jugular venous pulse was recorded during the study. In 61 patients, invasive central venous pressure (CVP) was registered as well. CVP increase is thought to be related with the timing between atria and ventricle depolarization; two groups were prespecified, the short VA interval tachycardias (including typical AVNRT and atrioventricular reciprocating tachycardia (AVRT) mediated by a septal accessory pathway) and the long VA interval tachycardias (including atypical AVNRT and AVRT mediated by a left free wall accessory pathway). The relationship between cannon A waves and AVNRT did not reach the statistical significance (OR: 3.01; p=.058); On the other hand, it was clearly associated with the final diagnosis of a short VA interval tachycardia (OR: 10.21; p<.001). CVP increase showed an inversely proportional relationship with the VA interval during tachycardia (b=-.020; p<.001). CVP increase was larger in cases of AVNRT (4.0mmHg vs. 1.2mmHg; p<.001) and short VA interval tachycardias (3.9mmHg vs. 1.2mmHg; p<.001). The presence of cannon A waves is associated with the final diagnosis of short VA interval tachycardias.

Local VA index for the differential diagnosis of supraventricular tachycardia

BackgroundDifferentiating between atypical atrioventricular nodal reentrant tachycardia (AVNRT) and orthodromic reciprocating tachycardia utilizing a septal accessory pathway is a complex challenge. ObjectiveThe purpose of this study was to describe the "local VA index," a straightforward method based on signals from the coronary sinus catheter, to distinguish between these arrhythmias during tachycardia and entrainment. The ventriculoatrial (VA) interval on the coronary sinus catheter is measured during tachycardia and entrainment, at the site of earliest atrial activity. The difference between these 2 situations defines the “local VA index.” We also propose a mechanism to clarify the limitations of historical pacing maneuvers, such as postpacing interval minus tachycardia cycle length (PPI-TCL) and stimulus–atrial interval minus ventriculoatrial interval (SA-VA), by examining nodal decrement and intraventricular conduction delay. MethodsIn a retrospective study of 75 patients referred for supraventricular tachycardia evaluation, 37 were diagnosed with atrioventricular reentrant tachycardia (AVRT) with orthodromic reciprocating tachycardia, and 38 with AVNRT (27 typical, 11 atypical). ResultsIn comparison to AVRT patients, AVNRT patients exhibited longer PPI-TCL (176 ± 47 ms vs 113 ± 42 ms; P <.01) and SA-VA (138 ± 47 ms vs 64 ± 28 ms; P <.01). The AVRT group had mean local VA index of –1 ± 13 ms, whereas the AVNRT group had a significantly longer index of 91 ± 46 ms (P <.01). An optimal threshold for differentiation was a local VA index of 40 ms. Importantly, there was no significant correlation between pacing cycle length and nodal decrement as well as intraventricular delay related to pathway location. This interindividual variability might explain misleading interpretations of PPI-TCL and SA-VA. ConclusionThis novel approach is advantageous because of its simplicity and effectiveness, requiring only 2 diagnostic catheters. A local VA interval difference <40 ms provides a clear distinction for AVRT.

Understanding the modern-era management of cardiac tachyarrhythmias

Diagnosis and treatment modalities of supraventricular arrhythmias have been changed over the past decade. This article mainly outlines advances in diagnosis and modern-day management of supraventricular tachycardia as well as an overview of the management of wide complex tachyarrhythmias. The role of cardiac electrophysiology study and radiofrequency catheter ablation in the diagnosis and management of a wide variety of supraventricular arrhythmias is also discussed. This article also emphasizes the current evidence-based management of atrial-origin tachyarrhythmias such as atrial flutter and fibrillation.The management of cardiac arrhythmias has changed over the past decade, which is mainly due to improvements in catheter ablation including 3D mapping catheter ablation, improvements in device therapy such as implantable cardioverter defibrillator (ICD) and biventricular pacing therapy (CRT) which have evolved to treat many conditions. Catheter ablation has moved from being a treatment considered only for patients with refractory arrhythmias to a first-line treatment. In the new era, catheter ablation is also used to treat atrial origin tachyarrhythmias such as atrial fibrillation (AF) and atrial flutter as well as ventricular tachycardia (epicardial VT ablation). Improvement of imaging modalities such as 2D/3D echocardiogram and cardiac MRI also play a vital role in the prognosis of ablation particularly in AF and epicardial VT ablation. Improvement in device implantation such as ICD and biventricular pacing also helpful in managing tachyarrhythmia. Modern advancements in cardiac electrophysiology help patients to improve their quality of life and prevent sudden cardiac deaths due to cardiac arrhythmia.

Diagnostic accuracy of Apple Watch Series 6 recorded single-lead ECGs for identifying supraventricular tachyarrhythmias: a comparative analysis with invasive electrophysiological study.

The advancements in wearable technology have made the detection of arrhythmias more accessible. While smartwatches are commonly used to detect patients with atrial fibrillation, their effectiveness in the differential diagnosis of supraventricular tachycardias (SVT) lacks consensus. A study was conducted on 47 patients with documented SVTs on a 12-lead ECG. All patients in the cohort underwent electrophysiology study with induction of SVT. A 6th generation Apple Watch was used to record ECG tracings during baseline sinus rhythm and during induced SVT. Cardiology residents and attending cardiologists evaluated these recordings to diagnose the differential diagnosis of SVT. The evaluation revealed 27 cases of typical atrioventricular nodal reentrant tachycardia (AVNRT), 11 cases of atrioventricular reentrant tachycardia (AVRT), and 9 cases of atrial tachycardia/atrial flutter (AT/AFL) among the induced tachycardias. Attending physicians achieved an accuracy of 66.0 to 76.6%, and residents demonstrated accuracy rates between 68.1 and 74.5%. Interrater reliability was assessed using Fleiss's Kappa method, resulting in a moderate level of agreement between residents (Kappa = 0.465, p < 0.001, 95% CI 0.30-0.63) and attendings (Kappa = 0.519, p < 0.001, 95% CI 0.35-0.68). The overall Kappa value was 0.417 (p < 0.001, 95% CI 0.34-0.49). Smartwatch recordings demonstrate moderate feasibility in diagnosing SVT when following a pre-specified algorithm. However, this diagnostic performance was lower than the accuracy obtained from 12-lead ECG tracings when blinded to procedure outcomes.

Abstract 12248: Anemia Impacts Mortality, Length of Stay and Resources Utilization on Patients Admitted With Primary Diagnosis of Ventricular Tachycardia: A Nationwide Analysis 2016 - 2020

Introduction: Ventricular Tachycardia is a life threating arrhythmia with large admission amount. In this analysis, authors aim to investigate the impact of anemia in patients admitted due to ventricular tachycardia in terms of mortality, length of stay and total hospital charges. Methods: This is an analysis of the National Inpatient Sample Database of the years 2016-2020. Adult patients admitted non elective with a primary diagnosis of ventricular tachycardia, with or without a secondary diagnosis of anemia were identified using the ICD-CM codes. The primary outcome was mortality. Secondary outcomes were length of stay and resources utilization. Multivariate logistic analysis was performed, and outcomes were adjusted by age, gender, race, Charlson comorbidity index, hospital location, size, region, teaching status and insurance. Data was considered statistically significant with p-value &lt;0.05. Results: Among 221720 patients who had a primary diagnosis of ventricular tachycardia, 17.56% had anemia. Adjusted mortality was significantly different in patients with secondary diagnosis of any anemia with odds ratio 1.95, p value &lt; 0.001, 95% Confidence Interval 1.73 - 2.2. In terms of Length of Stay, patients with anemias of any type stayed 3.09 more days in the hospital when compared to general population, p value &lt; 0.001, 95% Confidence Interval 2.78 - 3.41. Patients with anemia also had an increase on their total hospital charges by 61507.92 dollars, p value &lt; 0.001, 95% Confidence Interval 53771.36 - 69244.48. Conclusions: Patients with anemia had 1.95 higher mortality rate, stayed 3.09 more days in the hospital and had a total hospital cost higher by 61507.92$. Anemia can be a risk marker within patients admitted with ventricular tachycardia, more studies needed to investigate if the treatment of anemia improves the outcome.

Abstract 16042: Sex/Gender Specific Differences in the Outcomes of Ventricular Arrhythmias Complicating Acute Myocardial Infarction

Introduction: Ventricular Arrythmias (VA) is a common clinical problem in myocardial ischemia and the most common cause of sudden death in patients with Acute Myocardial Infarction (AMI). Studies have shown sex differences in the incidence, presentation, and outcomes of AMI. However, evidence on the sex differences in VA in patients with AMI is limited. In this study we evaluated the sex differences in the incidence and in- hospital outcomes of VA in patients who were admitted with AMI. Methods: Using the NIS 2016 - 2020, we retrospectively analyzed the data of patients admitted for AMI using the ICD 10 code (I21). Our primary population included patients who underwent reperfusion (PCI or CABG), 18 years and above, and had a secondary diagnosis of either Ventricular Fibrillation (VF) or Ventricular Tachycardia (VT). We excluded patients who had infiltrative cardiac diseases (Sarcoidosis, Lyme disease, amyloidosis) or long QT syndrome. We further divided our sample population into 2 groups based on their reported gender (Male or Female). Using a multivariate analysis, we compared the odds of VA and in-hospital outcomes between both subgroups of patients. Results: We identified 174,565 patients with VA in the setting of AMI. Of these 75.8% were males. VF was observed in 15,500 (36.4%) of female patients and 45,010 (34%) of male patients. The odds of VA after AMI were higher in Men (AOR): 1.72, CI: 1.67 - 1.78, p&lt;0.001). Male patients were more likely to have a history of myocardial infarction, smoking and Cocaine use while female patients were more likely to have DM, PVD and heart failure. Female patients had significantly higher odds of in-hospital mortality (AOR: 1.32, CI: 1.21 - 1.42, p&lt;0.001), cardiogenic shock (AOR: 1.08, CI: 1.01 - 1.15, p&lt;0.022) and Cardiac arrest (AOR:1.11, CI: 1.03 - 1.18, p&lt;0.002). However, they had significantly lower odds of defibrillator insertion (AOR: 0.57, CI: 0.47 - 0.68, p&lt;0.001) or catheter ablation (AOR: 0.51, CI: 0.27 - 0.98, p&lt;0.001) during the index admission. Conclusion: There are sex differences in the incidence and outcomes of VA in AMI, with women having lower odds of VA but worse hospital outcomes. Incorporation of women in more VA studies and may help us understand why these differences in outcomes exists

Ventricular Tachycardia.

This scenario was developed to educate emergency medicine residents on the diagnosis and management of ventricular tachycardia (VT) that is refractory to single dose anti-arrhythmic management. Electrical storm, defined as three or more episodes of sustained VT, ventricular fibrillation, or appropriate shocks from an implantable cardioverter defibrillator within 24 hours,1 has a mortality rate up to 14% in the first 48 hours.2 Ventricular tachycardia may present in a heterogenous fashion, not only with stable versus unstable clinical presentations, but also with different electrocardiographic morphologies and etiologies.1 Understanding how to rapidly diagnose, treat, and utilize second or third-line treatments is vital in the setting of refractory ventricular tachycardia rather than relying on the success of first-line agents. Appreciation for what medications are readily available in your crash cart and medication dispensing cabinet is critical for timely management for refractory ventricular tachycardia. At the conclusion of the simulation session, learners will be able to: 1) identify the different etiologies of VT, including structural heart disease, acute ischemia, and acquired or congenital QT syndrome; 2) describe confounding factors of VT, such as electrolyte abnormalities and sympathetic surge; 3) describe how to troubleshoot an unsuccessful synchronized cardioversion, including checking equipment connections, increasing delivered energy, and changing pad placement; 4) compare and contrast treatments of VT based on suspected underlying etiology; 5) describe reasons to activate the cardiac catheterization lab other than occlusive myocardial infarction; and 6) identify appropriate disposition of the patient to the cardiac catheterization lab. This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on the diagnosis, differential diagnosis, and management of VT. Debriefing methods may be left to the discretion of participants, but the authors have utilized advocacy-inquiry techniques. This scenario may also be run as an oral board case. Our residents are provided a survey at the completion of the debriefing session so they may rate different aspects of the simulation, as well as provide qualitative feedback on the scenario. The local institution's simulation center's electronic feedback form is based on the Center of Medical Simulation's Debriefing Assessment for Simulation in Healthcare (DASH) Student Version Short Form3 with the inclusion of required qualitative feedback if an element was scored less than a 6 or 7. Twelve learners completed a feedback form. This session received 6 and 7 scores (consistently effective/very good and extremely effective/outstanding, respectively) other than three isolated 5 scores. The lowest average score was 6.67 for "Before the simulation, the instructor set the stage for an engaging learning experience." The highest average score was 7 for "The instructor helped me see how to improve or how to sustain good performance." The form also includes an area for general feedback about the case at the end. Illustrative examples of feedback include: "Excellent care and debrief." Specific scores are available upon request. This is a cost-effective method for reviewing VT diagnosis and management. The case may be modified for appropriate audiences, such as describing what medications may be readily available in a free-standing emergency department or pre-hospital setting. Medical simulation, ventricular tachycardia, cardiac emergencies, dysrhythmias, cardiology, emergency medicine.

Diagnosis and management of ventricular tachycardia

Ventricular tachycardia (VT) describes rapid heart rhythms originating from the ventricles. Accurate diagnosis of VT is important to allow prompt referral to specialist services for ongoing management. The diagnosis of VT is usually made based on electrocardiographic data, most commonly 12-lead echocardiography (ECG), as well as supportive cardiac telemetric monitoring. Distinguishing between VT and supraventricular arrhythmias on ECG can be difficult. However, the VT diagnosis frequently needs to be made rapidly in the acute setting. In this review, we discuss the definition of VT, review features of wide-complex tachycardia (WCT) on ECG that might be helpful in diagnosing VT, discuss the different substrates in which VT can occur and offer brief comments on management considerations for patients found to have VT.

Spontaneous variation of ventriculoatrial interval after tachycardia induction: determinants and usefulness in the diagnosis of supraventricular tachycardias with long ventriculoatrial interval

Abstract Funding Acknowledgements Type of funding sources: None. Background Determining the mechanism of supraventricular tachycardias with prolonged ventriculoatrial (VA) intervals is sometimes a challenge, because the usual diagnostic manoeuvers based on pacing during the ongoing tachycardia cannot be performed or do not offer diagnostic accuracy. Purpose To analyse the determinants, time course and diagnostic accuracy (atypical atrioventricular nodal reentrant tachycardias [AVNRT] versus orthodromic reentrant tachycardias through an accessory pathway [ORT]) of spontaneous VA intervals variation in patients with narrow QRS tachycardias and prolonged VA. Methods A total of 156 induced tachycardias were studied (44 with atypical AVNRT and 112 with ORT). Two sets of 10 measurements were performed for each patient: after tachycardia induction and one minute later. VA and VV intervals were determined. Results Among patients with AVNRT, there was a marked variability in the VA intervals after induction (Mn-VA: mean beat-to-beat variation of VA; MX-VA: maximum of the beat-to-beat VA variation). Figure 1. No significant differences were found in the variability of the VA interval between slow-slow versus fast-slow atypical AVNRTs (p&amp;gt;0.5 in all comparisons). And, even though the variability of the VA interval at one minute continued to be considerable, it tended to decrease after induction. However, as shown in Figure 1, in subjects with ORT, no relevant beat-to-beat changes in the duration of the VA intervals were seen, neither after induction nor at one minute later. The values of VA interval variability in ORT with septal versus free-wall accessory pathways were similar. Additionally, in 9 (20%) patients with atypical AVNRT and in 11 (10%) with ORT the Dif-VA increased from induction to one minute, with the maximum increment being of 29 ms and 6 ms, respectively. The difference between the longest and the shortest VA interval (Dif-VA) correlates significantly with the diagnosis of atypical AVNRT (C coefficient=0.95 and 0.85 after induction and at one minute, respectively; p&amp;lt;0.001). A Dif-VA ≥15 ms presents a sensitivity and specificity for atypical AVNRT of 50% and 99%, respectively after induction, and of 27% and 100% one minute later. Figure 2. We found a robust and significant correlation between the fluctuations of VV and VA intervals in atypical AVNRTs (Coefficient Rho: 0.56 and 0.76, after induction and at one minute, respectively; p&amp;lt;0.001 for both) but not in ORTs. Conclusions The analysis of VA interval variability after induction and at one minute later correctly discriminates atypical AVNRT from ORT in almost all cases. Such variability of VA intervals is related to the fluctuations of VV intervals in atypical AVRNTs but not in ORTs.