Pattern Recognition and Inductive-Deductive Reasoning: Two Cornerstones of Electrocardiogram Teaching.

Almost half of physicians report being uncomfortable with ECG interpretation, underscoring the need for high-quality ECG training. There are two major strategies for teaching ECG interpretation. Pattern recognition involves reading ECGs solely as graphic images, after being taught the underlying pathophysiology behind the ECG patterns. Inductive-deductive reasoning requires logical thought mechanisms, using clinical context and algorithms, to reach a correct diagnosis. It is important for ECG educators to choose between these teaching strategies, depending on the clinical scenario. Hopefully, consistency around teaching strategies will help learners to become more comfortable in ECG interpretation, and ultimately correctly interpret ECGs more frequently.

Sleep Quality, Nutrient Intake, and Social Development Index Predict Metabolic Syndrome in the Tlalpan 2020 Cohort: A Machine Learning and Synthetic Data Study.

This study investigated the relationship between Metabolic Syndrome (MetS), sleep disorders, the consumption of some nutrients, and social development factors, focusing on gender differences in an unbalanced dataset from a Mexico City cohort. We used data balancing techniques like SMOTE and ADASYN after employing machine learning models like random forest and RPART to predict MetS. Random forest excelled, achieving significant, balanced accuracy, indicating its robustness in predicting MetS and achieving a balanced accuracy of approximately 87%. Key predictors for men included body mass index and family history of gout, while waist circumference and glucose levels were most significant for women. In relation to diet, sleep quality, and social development, metabolic syndrome in men was associated with high lactose and carbohydrate intake, educational lag, living with a partner without marrying, and lack of durable goods, whereas in women, best predictors in these dimensions include protein, fructose, and cholesterol intake, copper metabolites, snoring, sobbing, drowsiness, sanitary adequacy, and anxiety. These findings underscore the need for personalized approaches in managing MetS and point to a promising direction for future research into the interplay between social factors, sleep disorders, and metabolic health, which mainly depend on nutrient consumption by region.

Interamerican Society of Cardiology (CIFACAH - ELECTROSIAC)/Latin American Heart Rhythm Society (LAHRS): multidisciplinary review on the appropriate use of cardiac resynchronization therapy in heart failure.

Epidemiological studies suggest that approximately half of the patients with heart failure (HF) have reduced ejection fraction, while the other half have normal ejection fraction (EF). Currently, international guidelines consider QRS duration greater than 130 ms, in the presence of ventricular dysfunction (EF < 35%), as a criterion for selecting patients for cardiac resynchronization therapy (CRT). CRT helps restore intraventricular and auriculoventricular synchrony, improving left ventricular (LV) performance, reducing functional mitral regurgitation, and inducing reverse LV remodeling. This is evidenced by increased LV filling time and left ventricular ejection fraction, decreased LV end-diastolic and end-systolic volumes, mitral regurgitation, and septal dyskinesia. Because the mechanisms of dyssynchrony may be heterogeneous, no single measure may accurately predict response to CRT. Finally, CRT has been progressively shown to be safe and feasible, improves functional status and quality of life, reversely remodels the LV, decreases the number of hospitalizations, total mortality in patients with refractory HF, LV dysfunction, and intraventricular conduction disorders; is a pacemaker-based therapy for HF and thanks to current technology, safe remote monitoring of almost all types of cardiac devices is possible and provides useful alerts in clinical practice.

Los estudios epidemiológicos sugieren que aproximadamente la mitad de los pacientes con insuficiencia cardiaca (IC) tiene fracción de eyección reducida, mientras que la otra mitad, fracción de eyección (FE) normal. Actualmente, las guías internacionales consideran la duración de QRS mayor a 130 ms, en presencia de disfunción ventricular (FE < 35%), como criterio para selección de pacientes a terapia de resincronización cardiaca (TRC). La TRC ayuda a restaurar la sincronía intraventricular y auriculoventricular, mejorando el rendimiento del ventrículo izquierdo (VI), reduciendo la regurgitación mitral funcional e induciendo la remodelación inversa del VI. Esto se evidencia en el aumento del tiempo de llenado del VI y la fracción de eyección del VI, la disminución de los volúmenes telediastólico y telesistólico del VI, y la regurgitación mitral y discinesia septal. Como los mecanismos de la disincronía pueden ser heterogéneos, es posible que ninguna medida prediga con exactitud la respuesta a la TRC. Finalmente, la TRC cardiaca ha demostrado progresivamente ser segura y factible, mejora el estado funcional y la calidad de vida, remodela inversamente el VI, disminuye el número de hospitalizaciones, la mortalidad total en pacientes con IC refractaria, la disfunción ventricular izquierda y los trastornos de conducción intraventricular; es una terapia basada en marcapasos para la IC y gracias a la tecnología actual es posible realizar una supervisión remota y segura de casi todos los tipos de dispositivos cardiacos y obtener alertas útiles en la práctica clínica.

Validation of qrs-polarity algorithm with special emphasis in parahisian pathways / Validación del algoritmo de la polaridad del qrs con especial énfasis en vías parahisianas

Abstract Background: In 1996 Iturralde et al. published an algorithm based on the QRS polarity to determine the location of the accessory pathways (AP), this algorithm was developed before the massive practice of invasive electrophysiology. Purpose: To validate the QRS-Polarity algorithm in a modern cohort of subjects submitted to radiofrequency catheter ablation (RFCA). Our objective was to determinate its global accuracy and its accuracy for parahisian AP. Methods: We conducted a retrospective analysis of patients with Wolff-Parkinson-White (WPW) syndrome who underwent an electrophysiological study (EPS) and RFCA. We employed the QRS-Polarity algorithm to predict the AP anatomical location and we compared this result with the real anatomic location determined in the EPS. To determine accuracy, the Cohen's kappa coefficient (k) and the Pearson correlation coefficient were used. Results: A total of 364 patients were included (mean age 30 years, 57% male). The global k score was 0.78 and the Pearson's coefficient was 0.90. The accuracy for each zone was also evaluated, the best correlation was for the left lateral AP (k of 0.97). There were 26 patients with a parahisian AP, who showed a great variability in the ECG features. Employing the QRS-Polarity algorithm, 34.6% patients had a correct anatomical location, 42.3% had an adjacent location and only 23% an incorrect location. Conclusion: The QRS-Polarity algorithm has a good global accuracy; its precision is high, especially for left lateral AP. This algorithm is also useful for the parahisian AP.

Resumen Antecedentes: En 1996 Iturralde y colaboradores publicaron un algoritmo basado en la polaridad del QRS para determinar la ubicación de las vías accesorias (VA), este algoritmo fue desarrollado antes de la práctica masiva de la electrofisiología invasiva. Objetivo: Validar el algoritmo de la polaridad del QRS en una cohorte moderna de sujetos sometidos a ablación con catéter por radiofrecuencia (ACRF). Nuestro objetivo fue determinar su precisión global y su precisión para las VA parahisianas. Métodos: Realizamos un análisis retrospectivo de pacientes con síndrome de Wolff-Parkinson-White (WPW) a los que se les realizó estudio electrofisiológico (EEF) y ACRF. Empleamos el algoritmo de la polaridad del QRS para predecir la ubicación anatómica de la VA y comparamos este resultado con la ubicación anatómica real determinada en el EEF. Para determinar la precisión se utilizaron el coeficiente kappa de Cohen (k) y el coeficiente de correlación de Pearson. Resultados: Se incluyeron un total de 364 pacientes (edad media 30 años, 57 % varones). La puntuación k global fue de 0,78 y el coeficiente de Pearson de 0,90. También se evaluó la precisión para cada zona, la mejor correlación fue para las VA laterales izquierdas (k de 0.97). Hubo 26 pacientes con VA parahisianas, que mostraron una gran variabilidad en las características del ECG. Empleando el algoritmo de la polaridad del QRS, el 34,6 % de los pacientes tenía una ubicación anatómica correcta, el 42,3 % tenía una ubicación adyacente y solo el 23 % una ubicación incorrecta. Conclusión: El algoritmo de la polaridad del QRS tiene una buena precisión global; su precisión es alta, especialmente para VA lateral izquierdo. Este algoritmo también es útil para la VA parahisiana.

[Interamerican Society of Cardiology (CIFACAH - ELECTROSIAC)/Latin American Heart Rhythm Society (LAHRS): multidisciplinary review on the appropriate use of cardiac resynchronization therapy in heart failure]. / Sociedad Interamericana de Cardiología (CIFACAH-ELECTROSIAC)/Sociedad Latinoamericana de Ritmo Cardiaco (LAHRS): revisión multidisciplinaria sobre el uso apropiado de la terapia de resincronización cardiaca en la insuficiencia cardiaca.

Epidemiological studies suggest that approximately half of the patients with heart failure (HF) have reduced ejection fraction, while the other half have normal ejection fraction (EF). Currently, international guidelines consider QRS duration greater than 130 ms, in the presence of ventricular dysfunction (EF < 35%), as a criterion for selecting patients for cardiac resynchronization therapy (CRT). CRT helps restore intraventricular and auriculoventricular synchrony, improving left ventricular (LV) performance, reducing functional mitral regurgitation, and inducing reverse LV remodeling. This is evidenced by increased LV filling time and left ventricular ejection fraction, decreased LV end-diastolic and end-systolic volumes, mitral regurgitation, and septal dyskinesia. Because the mechanisms of dyssynchrony may be heterogeneous, no single measure may accurately predict response to CRT. Finally, CRT has been progressively shown to be safe and feasible, improves functional status and quality of life, reversely remodels the LV, decreases the number of hospitalizations, total mortality in patients with refractory HF, LV dysfunction, and intraventricular conduction disorders; is a pacemaker-based therapy for HF and thanks to current technology, safe remote monitoring of almost all types of cardiac devices is possible and provides useful alerts in clinical practice.

Los estudios epidemiológicos sugieren que aproximadamente la mitad de los pacientes con insuficiencia cardiaca (IC) tiene fracción de eyección reducida, mientras que la otra mitad, fracción de eyección (FE) normal. Actualmente, las guías internacionales consideran la duración de QRS mayor a 130 ms, en presencia de disfunción ventricular (FE < 35%), como criterio para selección de pacientes a terapia de resincronización cardiaca (TRC). La TRC ayuda a restaurar la sincronía intraventricular y auriculoventricular, mejorando el rendimiento del ventrículo izquierdo (VI), reduciendo la regurgitación mitral funcional e induciendo la remodelación inversa del VI. Esto se evidencia en el aumento del tiempo de llenado del VI y la fracción de eyección del VI, la disminución de los volúmenes telediastólico y telesistólico del VI, y la regurgitación mitral y discinesia septal. Como los mecanismos de la disincronía pueden ser heterogéneos, es posible que ninguna medida prediga con exactitud la respuesta a la TRC. Finalmente, la TRC cardiaca ha demostrado progresivamente ser segura y factible, mejora el estado funcional y la calidad de vida, remodela inversamente el VI, disminuye el número de hospitalizaciones, la mortalidad total en pacientes con IC refractaria, la disfunción ventricular izquierda y los trastornos de conducción intraventricular; es una terapia basada en marcapasos para la IC y gracias a la tecnología actual es posible realizar una supervisión remota y segura de casi todos los tipos de dispositivos cardiacos y obtener alertas útiles en la práctica clínica.

Validation of qrs-polarity algorithm with special emphasis in parahisian pathways.

BACKGROUND: In 1996 Iturralde et al. published an algorithm based on the QRS polarity to determine the location of the accessory pathways (AP), this algorithm was developed before the massive practice of invasive electrophysiology. PURPOSE: To validate the QRS-Polarity algorithm in a modern cohort of subjects submitted to radiofrequency catheter ablation (RFCA). Our objective was to determinate its global accuracy and its accuracy for parahisian AP. METHODS: We conducted a retrospective analysis of patients with Wolff-Parkinson-White (WPW) syndrome who underwent an electrophysiological study (EPS) and RFCA. We employed the QRS-Polarity algorithm to predict the AP anatomical location and we compared this result with the real anatomic location determined in the EPS. To determine accuracy, the Cohen's kappa coefficient (k) and the Pearson correlation coefficient were used. RESULTS: A total of 364 patients were included (mean age 30 years, 57% male). The global k score was 0.78 and the Pearson's coefficient was 0.90. The accuracy for each zone was also evaluated, the best correlation was for the left lateral AP (k of 0.97). There were 26 patients with a parahisian AP, who showed a great variability in the ECG features. Employing the QRS-Polarity algorithm, 34.6% patients had a correct anatomical location, 42.3% had an adjacent location and only 23% an incorrect location. CONCLUSION: The QRS-Polarity algorithm has a good global accuracy; its precision is high, especially for left lateral AP. This algorithm is also useful for the parahisian AP.

ANTECEDENTES: En 1996 Iturralde y colaboradores publicaron un algoritmo basado en la polaridad del QRS para determinar la ubicación de las vías accesorias (VA), este algoritmo fue desarrollado antes de la práctica masiva de la electrofisiología invasiva. OBJETIVO: Validar el algoritmo de la polaridad del QRS en una cohorte moderna de sujetos sometidos a ablación con catéter por radiofrecuencia (ACRF). Nuestro objetivo fue determinar su precisión global y su precisión para las VA parahisianas. MÉTODOS: Realizamos un análisis retrospectivo de pacientes con síndrome de Wolff-Parkinson-White (WPW) a los que se les realizó estudio electrofisiológico (EEF) y ACRF. Empleamos el algoritmo de la polaridad del QRS para predecir la ubicación anatómica de la VA y comparamos este resultado con la ubicación anatómica real determinada en el EEF. Para determinar la precisión se utilizaron el coeficiente kappa de Cohen (k) y el coeficiente de correlación de Pearson. RESULTADOS: Se incluyeron un total de 364 pacientes (edad media 30 años, 57 % varones). La puntuación k global fue de 0,78 y el coeficiente de Pearson de 0,90. También se evaluó la precisión para cada zona, la mejor correlación fue para las VA laterales izquierdas (k de 0.97). Hubo 26 pacientes con VA parahisianas, que mostraron una gran variabilidad en las características del ECG. Empleando el algoritmo de la polaridad del QRS, el 34,6 % de los pacientes tenía una ubicación anatómica correcta, el 42,3 % tenía una ubicación adyacente y solo el 23 % una ubicación incorrecta. CONCLUSIÓN: El algoritmo de la polaridad del QRS tiene una buena precisión global; su precisión es alta, especialmente para VA lateral izquierdo. Este algoritmo también es útil para la VA parahisiana.

Use of instant messaging in electrophysiological clinical practice in Latin America: a LAHRS survey.

AIMS: Instant messaging (IM) platforms are a prominent component of telemedicine and a practical tool for sharing clinical data and counselling. Purpose of the survey was to inquire about the use of IM, the platforms used, frequency, recipients, and contents in Latin America region. METHODS AND RESULTS: An online survey was sent to medical community via newsletter and social media channels. The survey consisted in 22 questions, in Spanish and Portuguese, collected on SurveyMonkey. A total of 125 responders from 13 Latin-American countries (79% male, mean age 46.1 ± 9.7 years) completed the survey. Most of the responders declared that they send (88.8%) and receive (97.6%) clinical data through IM apps. Most senders declare that they anonymize clinical data before sending (71.0 ± 38.3%), but that the data received is anonymized only in 51.4 ± 33.5%. The most common tests shared with other physicians were 12-lead electrocardiograms (99.2%), followed by Holter recordings (68.0%) and tracings from electrophysiological studies (63.2%). The majority (55.2%) said that are unaware of legal data protection rules in their countries. CONCLUSIONS: IM apps are used by medical professionals worldwide to share and discuss clinical data and are preferred to many other methods of data sharing and are often used to share many different types of clinical data. They are perceived as a fast and easy way of communication, but medical professionals should be aware of the appropriate use of IM to prevent legal and privacy issues.

Bioinformatics Insights on the Physicochemical Properties of SCN5A Mutant Proteins Associated with the Brugada Syndrome.

BACKGROUND: The Brugada syndrome (BrS) is a heart rhythm condition that is commonly associated with a strong predisposition for sudden cardiac death. Malignant ventricular arrhythmias could occur secondary to the dysfunction of the cardiac sodium voltage-gated Na(v)1.5 channel (SCN5A). OBJECTIVE: This study aimed to perform a multiparametric computational analysis of the physicochemical properties of SCN5A mutants associated with BrS using a set of bioinformatics tools. METHODS: In-house algorithms were calibrated to calculate, in a double-blind test, the Polarity Index Method (PIM) profile and protein intrinsic disorder predisposition (PIDP) profile of each sequence, and computer programs specialized in the genomic analysis were used. RESULTS: Specific regularities in the charge/polarity and PIDP profile of the SCN5A mutant proteins enabled the re-creation of the taxonomy, allowing us to propose a bioinformatics method that takes advantage of the PIM profile to identify this group of proteins from their sequence. CONCLUSION: Bioinformatics programs could reproduce characteristic PIM and PIDP profiles of the BrS-related SCN5A mutant proteins. This information can contribute to a better understanding of these altered proteins.

Supraventricular tachyarrhythmia and sinus node dysfunction as a first manifestation of short QT syndrome in a pediatric patient. Case Report.

Short QT syndrome (SQTS) represents a diagnosis challenge where the symptoms may vary from palpitations in an otherwise asymptomatic patient to sudden death. Is a recently discovered rare channelopathy, identified by Gussak in 2000, characterized by short QT intervals on the electrocardiogram and a tendency to develop atrial and ventricular arrhythmias in the absence of structural heart disease, hyperkalemia, hypercalcemia, hyperthermia, acidosis and endocrine disorders. We present the case of a 16-year-old patient with short QT-type channelopathy, who presented with sinus arrest and junctional rhythm, who later developed atrial tachycardia and atrial flutter.

Individual Factors Associated With COVID-19 Infection: A Machine Learning Study.

The fast, exponential increase of COVID-19 infections and their catastrophic effects on patients' health have required the development of tools that support health systems in the quick and efficient diagnosis and prognosis of this disease. In this context, the present study aims to identify the potential factors associated with COVID-19 infections, applying machine learning techniques, particularly random forest, chi-squared, xgboost, and rpart for feature selection; ROSE and SMOTE were used as resampling methods due to the existence of class imbalance. Similarly, machine and deep learning algorithms such as support vector machines, C4.5, random forest, rpart, and deep neural networks were explored during the train/test phase to select the best prediction model. The dataset used in this study contains clinical data, anthropometric measurements, and other health parameters related to smoking habits, alcohol consumption, quality of sleep, physical activity, and health status during confinement due to the pandemic associated with COVID-19. The results showed that the XGBoost model got the best features associated with COVID-19 infection, and random forest approximated the best predictive model with a balanced accuracy of 90.41% using SMOTE as a resampling technique. The model with the best performance provides a tool to help prevent contracting SARS-CoV-2 since the variables with the highest risk factor are detected, and some of them are, to a certain extent controllable.

Acute and long-term success of ventricular tachycardia ablation in patients with ischemic heart disease in a Mexican center.

Objective: . To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods: . We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results: . Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66-6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08-5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06-5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34-6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR 0.29, IC 95% 0.12-0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48-0.86, p=0.013) were protective factors. Conclusions: . Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it.

[Corrected QT interval and GRACE score relationship in patients with non-ST segment elevation myocardial infarction]. / Relación del intervalo QT corregido con la escala GRACE en pacientes con infarto de miocardio sin elevación del segmento ST.

Background: The Global Registry of Acute Coronary Events (GRACE) prediction model stratifies patients with non-ST-segment elevation myocardial infarction (NSTEMI). Corrected QT interval (QTc) is not considered in this model. Objective: To evaluate the relationship between the QTc interval and the GRACE score in patients with NSTEMI. Materials and methods: An observational, retrospective study was carried between 2016 and 2019. We included patients with diagnosis of NSTEMI, QTc intervals were calculated with Bazett's formula, and they were classified into 2 groups: a normal QTc interval (<440 ms) and prolonged (≥440 ms). According to the GRACE score they were classified in three ranges: low risk (≤109 points), intermedium (110 - 139 points) and high (≥140 points), we determined if there were a correlation between QTc interval and the GRACE score. Results: A total of 940 patients with a diagnosis of NSTEMI were admitted in our institution, 634 met the inclusion criteria, there were 390 patients with normal QTc interval and 244 with a prolonged QTc interval. Patients with prolonged QTc were older (65.5 vs 61, p=0.001) with a lower proportion of males (71.7% vs 82.8%, p=0.001). An association was found between the GRACE score and the QTC interval, subjects with a normal QTc had a greater proportion of low and intermediate risk than those with a prolonged QTc (p=0.001). Conclusions. In NSTEMI patients, a normal QTc interval (<440 ms) is associated with a GRACE risk score of low or intermediate risk.

Colchicine Is Safe Though Ineffective in the Treatment of Severe COVID-19: a Randomized Clinical Trial (COLCHIVID).

BACKGROUND: Colchicine is an available, safe, and effective anti-inflammatory drug and has been suggested as a COVID-19 treatment, but its usefulness in hospitalized severe COVID-19 patients has not been thoroughly demonstrated. OBJECTIVE: To address the safety and efficacy of colchicine in hospitalized patients with severe COVID-19. DESIGN: We conducted a triple-blind parallel non-stratified placebo-controlled clinical trial. PARTICIPANTS: We recruited 116 hospitalized patients with severe COVID-19 in Mexico. INTERVENTIONS: Patients were randomized to receive 1.5 mg of colchicine or placebo at the time of the recruitment in the study (baseline) and 0.5 mg BID PO to complete 10 days of treatment. MAIN MEASURES: The primary composite outcome was the progression to critical disease or death. Besides, we evaluated immunological features at baseline and after recovery or disease progression in 20 patients. KEY RESULTS: Fifty-six patients were allocated to colchicine and 60 patients received placebo. The study was suspended after the second interim analysis demonstrated colchicine had no effect on the primary outcome (OR 0.83, 95%CI 0.35-1.93, P = 0.67), nor in the days of ICU and hospital stays. Adverse events were similar between groups (OR 1.63, 95% CI 0.66-3.88, P = 0.37). After colchicine treatment, patients had higher BUN and lower serum levels of IL-8, IL-12p70, and IL-17A. CONCLUSIONS: Colchicine is safe but not effective in the treatment of severe COVID-19. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04367168.