electrocardiography

Acute myocarditis is a recognized complication of influenza infection, presenting with various characteristics. In this report, we present an atypical case of myocarditis that was successfully treated. Our patient was a 14-year-old girl who was admitted to the hospital due to drowsiness and loss of consciousness. Initially, she was diagnosed with hepatic encephalopathy due to elevated liver enzymes.Further cardiac monitoring and an ECG revealed a scary ST-segment elevation and a wide QRS complex in most leads. An echocardiogram indicated a significantly reduced left ventricular ejection fraction of 25%.Treatment commenced based on the presumptive diagnosis of myocarditis. Following partial recovery, cardiac magnetic resonance imaging was conducted, which confirmed the diagnosis.Ultimately, the patient was effectively treated for fulminant myocarditis, a complication arising from influenza infection, and was closely monitored until her cardiac function normalized. Recognizing this condition and its potential implications can facilitate the early detection and management of critical cardiac issues. (Iranian Heart Journal 2025; 26(2): 82-87)

Changes in electrocardiographic parameters are reported after hemodialysis (HD). This study determines the alternations in electrocardiographic parameters, hemodynamics, and body weight post-HD.

Electrocardiography was evaluated pre- and post-dialysis in 20 patients (55% males) aged 16.25±6.25 years. Changes in electrocardiographic parameters were compared considering changes in weight (post-dialysis and between dialysis sessions), blood pressure (BP) indices, and the occurrence of intra-dialysis hypotension (IDH).

A significant decrease was observed in weight, systolic, diastolic, and mean arterial BPs post-dialysis (P<0.05, for all). No substantial changes in durations of PR interval, QT interval corrected for heart rate, and QRS complex, as well as QT dispersion, were found post-dialysis (P>0.05 for all). Hemodynamic and electrocardiographic alternations were not significantly different between cases with adequate versus inadequate weight gain (P>0.05 for all). Meanwhile, dialysis-induced ventricular strain patterns (ST-T segment changes) were found in 20% of patients, including three cases with inadequate weight gain inter-dialysis. In one case, electrocardiographic findings of hyperkalemia resolved post-dialysis. Whereas, the left ventricular strain pattern appeared in one other case.

HD is associated with significant acute changes in systolic and diastolic BP and mean arterial pressure (MAP). These changes, if repeated frequently, can result in myocardial ischemia and infarction. HD protects the heart against hyperkalemia, and thereby arrhythmia; however, it causes ventricular strain patterns, which a predictive of adverse cardiovascular outcomes. Evaluating the long-term complications of hemodynamic and electrocardiogram changes in pediatric HD cases is suggested.

Cardiovascular Diseases (CVD) requires precise and efficient diagnostic tools. The manual analysis of Electrocardiograms (ECGs) is labor-intensive, necessitating the development of automated methods to enhance diagnostic accuracy and efficiency. This research aimed to develop an automated ECG classification using Continuous Wavelet Transform (CWT) and Deep Convolutional Neural Network (DCNN), and transform 1D ECG signals into 2D spectrograms using CWT and train a DCNN to accurately detect abnormalities associated with CVD. The DCNN is trained on datasets from PhysioNet and the MIT-BIH arrhythmia dataset. The integrated CWT and DCNN enable simultaneous classification of multiple ECG abnormalities alongside normal signals. This analytical observational research employed CWT to generate spectrograms from 1D ECG signals, as input to a DCNN trained on diverse datasets. The model is evaluated using performance metrics, such as precision, specificity, recall, overall accuracy, and F1-score. The proposed algorithm demonstrates remarkable performance metrics with a precision of 100% for normal signals, an average specificity of 100%, an average recall of 97.65%, an average overall accuracy of 98.67%, and an average F1-score of 98.81%. This model achieves an approximate average overall accuracy of 98.67%, highlighting its effectiveness in detecting CVD.  The integration of CWT and DCNN in ECG classification improves accuracy and classification capabilities, addressing the challenges with manual analysis. This algorithm can reduce misdiagnoses in primary care and enhance efficiency in larger medical institutions. By contributing to automated diagnostic tools for cardiovascular disorders, it can significantly improve healthcare practices in the field of CVD detection.

Abstract Using an effective method to enhance nurses’ knowledge of ECG interpretation is one of the most essential requirements for nursing managers. Self-directed learning approaches can help to introduce lifelong learning in learners, especially in clinical settings. This study purposed to detect the effect of the implementation of the clinical teammate nurse program on the critical care nurses’ knowledge of ECG interpretation on cardiac arrhythmia.  A pilot study was performed by a quasi-experimental design with a nonequivalent control group. The participants were 32 critical care nurses divided into two groups: the clinical teammate nurse program and control groups. The data were collected by a knowledge assessment questionnaire that measured nurses’ knowledge of ECG interpretation of cardiac arrhythmia. The nurses’ knowledge was measured three times: initial study, one month, and six months later. The mean and standard deviation of age of participants was 32.38±7.03 years. There was a significant difference between three scores of repeated measurement of nurses’ knowledge (p<0.001), as the nurses’ knowledge one month after the study was significantly higher than in the initial test six months later. Also, pairwise comparisons showed that nurses in the clinical teammate program had higher knowledge scores than the control group (p<0.001).  The clinical teammate nurse program can be used as an easy and economical way to improve nurses’ knowledge in interpreting ECG. This method can also be an excellent alternative to formal and traditional methods such as lecturing programs in continuing education programs.

Accurate detection of Atrial Fibrillation (AF) has great significance in the field of medical science which can reduce the rate of mortality and morbidity. The present study focuses on Electrocardiography (ECG) signal classification using dimensionality reduction techniques combined with R wave to R wave interval (RR interval) features.

In the first approach, Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Independent Component Analysis (ICA), and Probabilistic Principal Component Analysis (PPCA) are performed independently on denoised ECG signal using Discrete Wavelet Transform (DWT) for the classification of ECG signal. In the second approach, the dimensionality reduction techniques combined with RR interval features are used for the classification of ECG signal.

Machine Learning (ML) algorithms such as Decision Tree (DT), Support Vector Machine (SVM), and Deep Learning (DL) algorithms such as Long Short Term Memory (LSTM) and Bi-Directional LSTM (BiLSTM) are used for classification purposes.

The proposed methodology provided an overall accuracy of 93.65% with PCA and LSTM classifier and an overall accuracy of 99.45% with PCA combined with RR interval features and LSTM classifier. The developed technology has potential applications in many practical solutions.

Neonatal atrial flutter (NAF) is a rare type of macroreentrant supraventricular tachycardia. In this report, we describe a case of atrial flutter in an 8-day-old neonate with a total anomalous pulmonary venous connection. Additionally, we introduce a diagnostic triad for ECG identification of this condition. This triad is composed of 3 components: similar shapes of inter-QRS segments (SIS) in leads II, III, and aVF, different shapes of inter-QRS segments (DIS) in lead I, and the occurrence of 1 or multiple stretched M or inverted V shapes in the inter-QRS (IQS) segment in leads II, III, and aVF. We assessed the effectiveness of this triad through a validation cohort, using previously reported cases of NAF from the literature. The sensitivity rates for detecting SIS and DIS patterns and the singular or multiple reversed W or V signs were 100%, 81%, and 100%, respectively. Furthermore, all 3 components of the triad were found in 81% of neonates diagnosed with atrial flutter. The emergence of this triad can be attributed to the elimination of the isoelectric segment in ECG, caused by the extended duration of flutter waves originating from macroreentry within the atrium and the rapid atrial rate characteristic of atrial flutter.

Methadone is a synthetic opioid with a high affinity for opioid receptors, widely used as an effective intervention for opioid dependence and the management of acute and chronic pain. However, its use has been associated with serious cardiac side effects, including torsades de pointes (TdP) and prolonged QTc intervals. This study investigated the incidence of syncope and electrocardiogram (ECG) changes in individuals who underwent methadone treatment for addiction.

This cross-sectional study, conducted in Yazd in 2020, involved 100 participants seeking methadone treatment at an addiction clinic. A cardiologist recorded initial ECGs using a 12-lead ECG device, assessing parameters such as heart rhythm, QTc interval, and premature contractions. Participants were informed about the study procedures and the necessity of follow-up ECGs one week and three months after starting methadone. The researchers monitored the patients for three months with regular outpatient visits.

The findings revealed a significant difference in syncope incidence based on ECG rhythm on day seven and month three, with higher rates observed in patients exhibiting junctional rhythms or PVC (p-value=0.000). Additionally, a significant relationship was found between syncope frequency and U wave status at month three (p-value=0.046). No significant associations were noted for ST segment changes or T wave variations. Furthermore, higher methadone doses, longer QTc intervals on day seven, and prolonged PR intervals correlated with increased syncope occurrences.

This study indicates that ECG-related variables and methadone dosage significantly influence syncope incidence among treated patients. Specifically, individuals with junctional rhythms or PVC and those receiving higher doses of methadone were at greater risk for syncope. Monitoring PR and QTc intervals is crucial for preventing syncope in patients undergoing methadone treatment.

Torsade de pointes (TdP) is a deadly complication from drug-induced QT prolongation. Each of the 12 lead of an electrocardiogram (ECG) has a different length of QT interval, and thus might have a different performance in TdP prediction. This study aimed to determine the best ECG lead or set of leads in this regard.

This is a comparative prognostic accuracy study using a two-gate data gathering design. The population in this study was from two sources, a case group (Patients who had drug-induced TdP, which were identified through a systematic Medline search) and a control group (those who overdosed on QT-prolonging drugs, which included patients who were under the consultation of Medical Toxicology Services). The areas under the receiver operating characteristic curve (AUROC) of heart rate-corrected QT (QTc) in each single ECG lead and of a mean/median QTc from a set of ECG leads (17 index test) in predicting the risk of TdP were calculated and compared with each other, trying to find the best lead for this propose. QTc Interval measurements were done by four investigators (Interrater reliabilities 0.95).

Finally, we included 136 and 148 ECGs from TdP cases and controls, respectively. V3 lead had the highest frequency of longest QTc interval, among the leads. The lead having the longest QTc yielded the greatest AUROC in predicting TdP regardless of QT correction formulas (QTcFRA=0.9915, QTcRTH=0.9893, QTcBZT=0.9904). The mean QTc of 3 leads (lead II, plus any two of leads V2-V4), and a median QTc of 6 leads (I, II, aVF, V2, V4, V6) provided similar overall performance for TdP prediction (regardless of the type of QTc formula).

The longest QTc provided the greatest AUROC in predicting drug-induced TdP, however, the longest QTc is not located in a fixed individual lead in any patient. A less time-consuming method with comparable performance to that of the longest QTc was to use a mean QTc from 3 leads (lead II, plus any two of leads V2-V4). The potential clinical impact of this finding needs to be verified in a prospective cohort study.

This study aimed to compare the prevalence, age, sex, left ventricular ejection fraction, underlying conditions, and smoking status among patients with various types of premature ventricular contractions (PVCs) originating from the left ventricle with an inferior axis. The PVC patterns were investigated using ECG.

Patients who underwent successful catheter ablation for PVCs originating from the left ventricle with an inferior axis between 2017 and 2022 at the Rajaie Cardiovascular Medical and Research Institute were included in this study. Patient data, including ECG records, were collected by reviewing archived patient files.

A total of 377 patients aged 15 to 81 years were included in the study, with 56.8% being male. The most common PVC ablation site was the left coronary cusp (39.3%), followed by the right coronary cusp-left coronary cusp commissure (26%). Most of the patients (99.5%) experienced clinical symptoms, and the mean ejection fraction was 44/60%. Nearly 38.19% of the patients had a normal ejection fraction, while 31.56% had a mildly reduced ejection fraction.

The study revealed that left-sided PVCs were more prevalent in men and exhibited an increasing trend with age. Among the risk factors, hypertension showed a direct and superior association. The most common PVC pattern observed on ECG was characterized by a monophasic R wave, QS complexes in leads AVL and AVR, and an R/S ratio of less than 1 in lead I and leads V1–V2. The majority of patients with left-sided PVCs exhibited a transition in lead V3, often referred to as the “gray zone.” Additionally, a breakthrough transition pattern was predominantly noted in patients with the most common type of PVCs ablated from the summit, aortomitral continuity, and subvalvular regions. (Iranian Heart Journal 2024; 25(4): 59-72)

Brugada phenocopy is considered when a Brugada-type ECG pattern is present but with a low likelihood of true Brugada syndrome, as indicated by negative family history, genetic testing, or provocative testing with drugs, or ECG normalization after the removal of precipitants. Brugada phenocopy has been reported due to various causes such as fever and electrolyte imbalance. We describe a 22-year-old man who presented with aluminum phosphide poisoning, resulting in severe metabolic acidosis, myocarditis, and profound myocardial depression. He developed transient Brugada-like ECG changes and multiorgan dysfunction, requiring intensive management, including mechanical ventilation and inotropes. Brugada phenocopy is a rare manifestation of aluminum phosphide-associated toxic myocarditis. After a week of treatment, there was a significant improvement in cardiac function and overall clinical status.

 Smoking is one of the most important risk factors for cardiovascular diseases. Although numerous studies have evaluated the long-term consequences of smoking, few studies have assessed the short-term effects of smoking, especially on the electrical activity of the heart. The aim of this study was the evaluation of the acute effect of smoking on cardiac electrical function and hemodynamic indices in smokers.

Materials: 

In this single-arm pretest-posttest study, 130 healthy smokers participated if they had smoked at least 100 cigarettes in their lifetime and were smoking daily. After considering the exclusion criteria, participants were monitored before and 10 minutes after smoking by electrocardiography (ECG) to measure QT dispersion (QTD) and P-wave dispersion (PWD), systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate (HR), and respiration rate (RR). Finally, the data obtained before and after smoking were compared.

 The mean age of the participants was 40.3 ± 10.6 years (range 19 to 71 years). 55 (42.3%) participants smoked between 10-15 years and 67 (51.5%) smoked 10 to 20 pack-years. After smoking, SBP (127.3 ± 10.4 vs. 138.4 ± 12.8 mmHg), QTD (33.5 ± 9.6 vs. 43.9 ± 10.7 ms) and PWD (28.9 ± 6.6 vs. 34.5 ± 7.4 ms), HR (80.1±9.8 vs 87.6±9.9) increased significantly (P value <0.001). In other parameters, no significant differences were observed.

 Smoking is associated with an acute increase in QTD and PWD, and thus an increased risk of ventricular arrhythmias (e.g. Torsade’s de pointes), atrial fibrillation, sudden death, and other heart problems.

The purpose of this study is to evaluate a treatment for aluminum phosphide (ALP) poisoning, which is known as “rice tablet”.

In the present study, the impact of different doses of ethanolic extract of olive leaves (100, 200, and 400 mg/kg) on ALP (120 mg/kg)-induced cardiotoxicity was evaluated in anesthetized-gastrotomized adult male Wistar rats. Thirty-five rats were randomly assigned into five groups (n=7) as follows: control (AC) and treatment groups [ALP+Olea100 (AO100), ALP+Olea 200 (AO200), and ALP+Olea 400 (AO400)]. Physiological data including blood pressure, heart rate, electrocardiogram (ECG), as well as oxidative stress markers were measured in heart tissues.

ALP-intoxication led to perturbed normal ECG and increased oxidative stress. Administration of olive leaf extract at various concentrations, however, mitigated bradycardia after 90 minutes, following ALP-intoxication (in AO200), hypotension (in AO100), and cardiac conduction disturbances (decreased QTC in the AO200 30 (P<0.05), 60 (P<0.001), and 90 (P<0.05) minutes after intoxication)   and decreased PR 60 (P<0.05) and 90 minutes (P<0.01) after intoxication. This was compared with baseline as well as detrimental changes in cardiac electrophysiology [mitigated ST-segment elevation  in AO200  and depressed T-wave in the AO200 (P<0.05) and  AO400 (P<0.01)  groups 90 minutes after intoxication]

Based on these authentic results, it seems that olive leaf extracts can be useful in reducing the severity of symptoms in ALP-poisoned individuals and could be utilized in a poisoning emergency.

Predicting sudden cardiac death (SCD) using electrocardiogram (ECG) signals has come to the attention of researchers in recent years. One of the most common SCD identifiers is ventricular fibrillation (VF). The main objective of the present study was to provide an online prediction system of SCD using innovative ECG measures 10 minutes before VF onset. Additionally, it aimed to evaluate the different segments of the ECG signal (which depend on ventricular function) comparatively to determine the efficient component in predicting SCD. The ECG segments were QS, RT, QR, QT, and ST. After defining the ECG characteristic points and segments, innovative measures were appraised using the three-dimensional phase space of the ECG component. Tracking signal dynamics and lowering the computational cost make the feature suitable for online and offline applications. Finally, the prediction was performed using the support vector machine (SVM). Using the QR measures, SCD detection was realized ten minutes before its occurrence with an accuracy, specificity, and sensitivity of 100%. The superiority of the proposed system compared to the state-of-the-art SCD prediction schemes was revealed in terms of both classification performances and computational speed.

Beta thalassemia major (β-TM) is an inherited blood disorder. Affected patients require frequent blood transfusions, leading to iron deposition and end organ damage, particularly myocardial dysfunction. A 12-lead ECG is a readily available tool that could be used to screen for conduction abnormalities and arrhythmias as a marker of worsening myocardial function.  A total of 108 β-TM patients were evaluated for correlation between abnormal findings on the surface ECG and severity of myocardial iron deposition in magnetic resonance imaging as measured by T2* levels.  Patients with T2* below 20 msec had significantly longer PR intervals, P wave durations, and QTc intervals. Patients with T2* below 10 msec had the longest QRS duration and QRS activation times. Atrial fibrillation was more prevalent in patients with lower T2* levels. With a decrease in T2*, the probability of notching of QRS in the limb and precordial leads increased.  Abnormal ECG is prevalent in β-TM patients, and the frequency of changes increases with the severity of iron overload. A 12-lead ECG is a valuable and readily available tool for the early assessment of myocardial damage and the implementation of a timely and appropriate management strategy.

One-third of heart failure cases also represent conduction disorders, such as Left Bundle Branch Block (LBBB), which leads to mechanical defects and ventricular dyssynchrony. This study aims to investigate the correlation between the degree of LBBB and other electrocardiographic parameters, along with the severity of ventricular dysfunction and mitral regurgitation (MR).

In this cross-sectional study, 40 patients (20 women/20 men) with non-ischemic LBBB were selected by continuous sampling from the patients of Fatemeh Zahra Sari Hospital in 2019. Electrocardiography (including QRS duration, R voltage of organ leads, S voltage in precordial leads, Cornell index, Sokolow-Lyon index, QRS axis deviation and Notched QRS in lateral leads), echocardiography (including Left Ventricular Ejection Fraction (LVEF)) and MR degree) and Tissue Doppler Imaging were investigated in selected patients.

The mean age of the patients was 64±13.5 years. 77.5% had LVEF less than 35%, 57.5% had intraventricular dyssynchrony>60 and 60% had interventricular dyssynchrony>40. There was a significant correlation between the level of LVEF (r=-0.464, p=0.003) and MR severity (r=0.332, p=0.037) and the severity of intraventricular dyssynchrony. In addition, septal to lateral wall motion delay in patients with LVEF less than 35% was significantly related to the level of intraventricular dyssynchrony (r=0.6712, p=0.000). Among the ECG parameters in patients with LVEF less than 35%, there was only a significant relationship between the maximum R range and the degree of interventricular dyssynchrony (r=0.438, p=0.014).

Our results indicated that LVEF and MR were correlated with the degree of ventricular dyssynchrony and they could be considered as valuable markers for LBBB. Septum to lateral wall delay, and septum to posterior, were also correlated.

Perinatal asphyxia may cause multiple organ dysfunctions, including myocardial dysfunction. This study aimed to evaluate the prevalence and features of myocardial dysfunction in perinatal asphyxia.
This study was carried out on 31 neonates (≥37 weeks) with perinatal asphyxia who were admitted to the Neonatal Intensive Care Unit (NICU). The neonates underwent Electrocardiography (ECG) and Echocardiography (ECHO) in the first 72 hours of birth. Moreover, in the first 24 hours of birth, 1 cc of blood was taken from the patients for cardiac troponin I (cTnI) and creatine kinase-myocardial band (CK-MB) testing. Following that, venous blood gas was recorded one hour later.
The mean 1- and 5-min Apgar scores were 4±1.76 and 6.8±1.6, respectively. The mean value of serum cTnI was 4±1.76, and mean level of CK-MB was obtained at 136.51±258.51. ECGs were of grade 1. Mitral valve E-wave/Early diastolic (51%), followed by Tricuspid Regurgitation Vena Contracta (48.4%) was found to be the commonest ECHO abnormality, and Mitral annular plane systolic excursion (96.8%) was the most normal ECHO parameter. Infants with ECG grade 1 changes had a lower 5-min Apgar score (P=0.014), and higher serum cTnI level (P=0.002). ECG changes were not significantly correlated with the mean of Apgar at 1 min, umbilical vein PH, and CK-MB.
ECG and ECHO changes, serum troponin I level, and 5-min Apgar score were found to be the predictors for myocardial dysfunction caused by asphyxia in newborn infants

Utilization of doxorubicin (DOX) as a chemotherapy medication is limited due to its cardiotoxic effects. Carnosic acid exerts antioxidant, anti-inflammatory, besides cytoprotective effects. The objective of this study was to investigate the ability of carnosic acid to protect rat hearts and the MCF7 cell line against cardiotoxicity induced by DOX. The study involved the classification of male Wistar rats into seven groups: 1) Control 2) DOX (2 mg/kg, every 48h, IP, 12d), 3-5) Carnosic acid (10, 20, 40 mg/kg/day, IP, 16d)+ DOX, 6) Vitamin E (200 mg/kg, every 48h, IP, 16d)+ DOX 7) Carnosic acid (40 mg/kg/day, IP, 16d). Finally, cardiac histopathological alterations, ECG factors, carotid blood pressure, left ventricular function, heart-to-body weight ratio, oxidative (MDA, GSH), inflammatory (IL-1β, TNF-α), plus apoptosis (caspase 3, 8, 9, Bcl-2, Bax) markers were evaluated. DOX toxicity and carnosic acid ameliorative effect were evaluated on MCF7 cells using the MTT assay. DOX augmented the QRS duration, QA, RRI, STI, and heart-to-body weight ratio, and reduced HR, LVDP, Min dP/dt, Max dP/dt, blood pressure, boosted MDA, TNF-α, IL1-β, caspase 3,8,9, Bax/Bcl-2 ratio, decreased GSH content, caused fibrosis, necrosis, and cytoplasmic vacuolization in cardiac tissue but carnosic acid administration reduced the toxic effects of DOX. The cytotoxic effects of DOX were not affected by carnosic acid at concentrations of 5 and 10 μM. Carnosic acid as an anti-inflammatory and antioxidant substance is effective in reducing DOX-induced damage by enhancing antioxidant defense and modifying inflammatory signal pathway activity and can be used as an adjunct in treating DOX cardiotoxicity.

Cardiac injury in COVID-19 patients confers a worse prognosis. The interpretation of electrocardiography can be beneficial in the early diagnosis of probable cardiac involvement. After adjusting for other variables, we sought to determine if the initial ECG on admission could add additional prognostic value. In this single-center cross-sectional study, 1165 patients with a positive COVID-19 PCR between Feb 2020 and Nov 2021 were enrolled in our study. Patients were grouped according to their admitted units, and survivors to hospital discharge or non-survivors. Predictors of ICU admission and in-hospital mortality were determined using univariate analysis and a logistic regression model. The mean age was 55.6 ± 16.2 years and 52% were male. Out of 1165 patients, 149 deaths (12.8%) were recorded during hospitalization. Sinus tachycardia was the most common dysrhythmia, followed by premature atrial and ventricular beats, sinus bradycardia, and atrial fibrillation (28.6%, 5.6%, 3.9%, and 2.1%, respectively). Age (p<0.001), sex (p=0.006), history of diabetes mellitus (p=0.002), hypertension (p=0.018), ischemic heart disease (p=0.004), and cancer (p<0.001) were more frequent among non-survivors. Among ECG findings, tachycardia, low voltage QRS, ST-T changes, and dysrhythmia were related to an increased mortality risk. However, in regression analysis, only sex (OR 1.89, 95% CI 1.2 to 2.9, p=0.004), age (OR 1.03, 95% CI 1.02 to 1.05, p<0.001), and initial tachycardia (OR 1.02, 95% CI 1.01 to 1.03, p<0.001) were independent predictors of in-hospital mortality. Our data suggest that initial electrocardiographic findings could be helpful in distinguishing patients with an increased risk for ICU admission or in-hospital death.

Given electrocardiogram (ECG) interpretation as one of the diagnostical challenges for medical students and health professionals, this research was carried out to present an experience of web-based teaching method and novel approaches used for training of ECG interpretation.

This online program was conducted in three days. The main content of the class was taught during one hour, and after that, the teacher spent enough time for responding the asked questions. The components of a normal ECG and different changes that can occur in these waves were taught through clinical case-based scenarios using the web platform and Adobe Connect software. The participants' satisfaction was assessed with a 12-item questionnaire, and the short-term retention of ECG interpretation skill was examined by comparing the posttest scores with pretest.

A total of 224 individuals completed the course. Total satisfaction score was 53.05±6.98 (out of the maximum score of 60). Based on the results of the paired t test, the interpretation skill scores of the participants increased significantly from 2.5 ± 1.57 to 6.96 ± 1.89. (p<0.001, CI = -4.8 to- 4.11).

This web-based nationwide training program provided a supplementary resource for ECG learning among medical students and health-care providers.