Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 3 2024 07 31 153 161 Mohammad Sahebjam Department of Echocardiography, Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Akbar Shafiee Cardiac Primary Prevention Research Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 2023 08 09 2024 09 03 Aortic valve stenosis (AS) is the most common valvular heart disease in developed countries, with its prevalence on the rise due to aging populations. While severe AS has long been recognized as high-risk, recent studies have shed light on the significant association between moderate AS and cardiovascular morbidity and mortality. Yet, the data are still inconclusive. With noninvasive multi-modality imaging techniques advancing rapidly, we now have more insight into the underlying biology of AS. Echocardiography continues to serve as the primary noninvasive imaging modality for diagnosing and grading AS. This comprehensive review delves into the role of echocardiography in diagnosing moderate AS and how the findings can support clinicians in making well-informed decisions that impact patients’ prognoses. https://jthc.tums.ac.ir/index.php/jthc/article/view/1901

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 3 2024 07 31 162 169 Alireza Hosseini Department of Surgery, Chamran Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. Mehran Shahzamani Department of Surgery, Chamran Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. Atefe Hashemabadi Department of Blood Circulation Technology, Isfahan University of Medical Sciences, Isfahan, Iran. Alireza Andalib Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2023 04 23 2024 09 12 Background: Cardiopulmonary bypass (CPB) can adversely affect coagulation and systemic inflammatory response. Given that the optimal strategy for priming CPB in cardiac surgery remains a matter of debate, this study aimed to investigate the effects of albumin 20% and hydroxyethyl starch 6% as priming solutions on bleeding and interleukin-6 (IL-6) levels during CPB. Methods: This randomized clinical trial involved 40 patients undergoing coronary artery bypass surgery at Shahid Chamran Hospital between July 2021 and July 2022. Participants were assigned to 2 groups: the first group received 50 mL of albumin 20% as the priming solution for the CPB circuit, while the second group received 500 mL of hydroxyethyl starch 6%. Bleeding and IL-6 levels were assessed before and after the intervention. Results: The albumin group comprised 80.0% men and 20.0% women, with a mean age of 66.45±5.84 years. The hydroxyethyl starch 6% group consisted of 85.0% men and 15.0% women, with a mean age of 63.05±5.92 years (P>0.05). The findings revealed that 12 hours after CPB, the IL-6 level in the hydroxyethyl starch 6% group (mean: 171.6±77.71 pg/mL) was significantly higher than that in the albumin group (mean: 105.8±36.45 pg/mL; P=0.002). At 48 hours after CPB, the mean bleeding was not significantly different between the groups (P=0.950). Conclusion: Albumin 20% was more effective than hydroxyethyl starch 6% concerning IL-6 levels. However, no significant differences in bleeding were observed between the groups at 48 hours post-CPB. https://jthc.tums.ac.ir/index.php/jthc/article/view/1850

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 3 2024 07 31 170 183 EN Afsaneh Aein Department of Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Mahnaz Solhi Department of Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Ali Vashegani Farahani Cardiac Primary Prevention Research Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Aljasem School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Farshid Alaeddini Cardiac Primary Prevention Research Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Leila Janani Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Negar Omidi Cardiac Primary Prevention Research Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. & Department of Cardiovascular Imaging, Tehran Heart Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hossein Tagdisi Department of Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. 2023 05 11 2024 07 02 Background: An effective approach to preventing cardiovascular issues is the use of mobile health applications to improve modifiable risk factors. This protocol for a randomized controlled trial aims to evaluate the development and effectiveness of an educational mobile app that employs an integrated change model to reduce risk factors for atherosclerotic cardiovascular disease (ASCVD) among individuals aged 20 to 69 years. Methods: This study will be a parallel, randomized, single-blind clinical trial utilizing the randomized block design involving 430 participants. The participants will be divided into a control group receiving standard clinical care and an intervention group receiving standard clinical care along with app-based education, over approximately 6 months. Conclusion: This application has been designed to enhance motivation, awareness, and positive habits to reduce risk factors in individuals at increased risk of ASCVD. Consequently, the results could improve cardiovascular health knowledge, manage biological risk factors, and modify cardiac behaviors through mobile applications. This research is expected to present a promising approach to utilizing mobile apps for managing cardiovascular health and contribute to the growing body of research on digital health interventions. https://jthc.tums.ac.ir/index.php/jthc/article/view/1855

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 3 2024 07 31 184 191 EN Samereh Rasoli Department of Anesthesiology and Operating Room, School of Allied Medical Sciences Mazandaran University of Medical Sciences, Sari, Iran. Ebrahim Nasiri-Formi Department of Anesthesiology and Operating Room, School of Allied Medical Sciences, Traditional and Complementary Medicine Research Center, Addiction Institute Mazandaran University of Medical Sciences, Sari, Mazandaran, Iran. Heydar Dadkhah-Tirani Department of Cardiac Surgery, School of Medicine, Heshmat Hospital, Guilan University of Medical Sciences, Rasht, Iran. Mohammad Esmaelpour-Bandboni Department of Cardiac Surgery, School of Medicine, Heshmat Hospital, Guilan University of Medical Sciences, Rasht, Iran. Aryan Asaolahpour Department of Medical Surgical Nursing, Heshmat Hospital, Guilan University of Medical Sciences, Rasht, Iran. 2023 05 16 2024 08 07 Background: Coronary artery bypass graft (CABG) surgery is a primary treatment for coronary artery occlusion. Anxiety is a common preoperative concern among patients undergoing this procedure. This study aimed to investigate the effect of listening to traditional Iranian music on anxiety in patients before CABG surgery. Methods: This randomized controlled trial involved 66 patients scheduled for CABG surgery. Patients were randomly assigned to either the control or intervention group, with 33 patients in each group. The intervention group listened to traditional music on an MP3 player for 20 minutes, while the control group received an MP3 player without music. Anxiety levels were measured using the Spielberger Anxiety Questionnaire before and after the intervention. Data were analyzed using the Student’s t-test, the paired t-test, and the Mann-Whitney U-test with SPSS software version 21. Results: There was no significant difference in anxiety severity between the 2 groups before the intervention (music group: 106.45±10.67 and control group: 116.36±9.78; P=0.798). However, after the intervention, there was a significant difference between the groups (music group: 65.82±7.54 vs control group: 113.72±13.04; P=0.001). There were no significant differences in physiological parameters (blood pressure, heart rate, and respiration rate) between the groups before the intervention (P<0.078). Following the intervention, systolic (P<0.013) and diastolic (P<0.003) blood pressure significantly decreased in the intervention group compared with the control group. Conclusion: Traditional Iranian music therapy can be a noninvasive, low-cost, and accessible tool to reduce anxiety in patients undergoing CABG surgery. https://jthc.tums.ac.ir/index.php/jthc/article/view/1859

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 3 2024 07 31 192 197 EN Maryam Moshkani Farahani Atherosclerosis Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Danial Samiei Nasr Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. Alireza Nasiri Atherosclerosis Research Center, Clinical Sciences Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran. Javad Soltanpour Department of Clinical Laboratory and Molecular Diagnosis, Baqiyatallah University of Medical Sciences, Tehran, Iran. 2023 07 03 2023 08 15 Background: Familial hypercholesterolemia (FH) is one of the most prevalent dyslipidemia disorders. This study investigated the demographic and lifestyle characteristics of patients with FH referred to a dyslipidemia clinic. Methods: This 5-year, single-center cross-sectional study focused on patients with low-density lipoprotein cholesterol (LDL-C) levels higher than 190 mg/dL referred to a dyslipidemia clinic in Tehran, Iran, between 2017 and 2022. The study examined their demographics, physical activity, and anxiety within the FH cohort. Results: A total of 1724 patients were referred to the dyslipidemia clinic. Of these patients, 44 were diagnosed with definite FH. The mean age and LDL-C level of the FH cohort were 38.84±16.85 years and 315.95±81.73 mg/dL, respectively. A significant correlation was found between LDL-C and body mass index (BMI) (correlation coefficient = -0.31, P=0.031) and total sleep duration (correlation coefficient = -0.40, P<0.000). No correlation was observed between age and physical activity or LDL-C levels. Additionally, no significant correlation was detected between the Dutch score and patients’ LDL-C, BMI, age, or physical activity. Regression analysis indicated that BMI and total sleep duration were independent predictors of LDL-C in the FH cohort. Conclusion: Investigating and identifying patients’ demographic and lifestyle characteristics is the first step in planning efficient and effective management strategies for chronic diseases, such as FH. Establishing a patient registry for chronic diseases enhances understanding of the target population and enables healthcare providers to design and implement appropriate preventive and control strategies. https://jthc.tums.ac.ir/index.php/jthc/article/view/1887

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 3 2024 07 31 198 205 Ghazaleh Asgharnezhad Department of Cellular and Molecular Biology, Faculty of Advanced Sciences and Technology, ‎Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Sachli Mohammadi Department of Cellular and Molecular Biology, Faculty of Advanced Sciences and Technology, ‎Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Mahdieh Mehrab Mohseni Department of Cellular and Molecular Biology, Faculty of Advanced Sciences and Technology, ‎Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Neda Mousvi-Niri Department of Biotechnology, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Maryam Naseroleslami Department of Cellular and Molecular Biology, Faculty of Advanced Sciences and Technology, ‎Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. 2023 10 31 2024 07 03 Background: Heart failure (HF) is a prevalent diagnosis with a significant mortality rate. Various therapeutic approaches exist for treating HF, and human adipose-derived mesenchymal stem cells-conditioned medium (hAMSCs-CM) therapy has emerged as a promising option. Despite its potential efficacy, the precise mechanism of action underlying hAMSCs-CM treatment remains unclear. To address this knowledge gap, we conducted a novel animal study to investigate the mechanism of action of hAMSCs-CM in an HF model, with a specific focus on transforming growth factor-β (TGF-β)/galectin-3, monocyte chemoattractant protein-1 (MCP1), B-type natriuretic peptide (BNP), and aldosterone (ALD). Methods: Forty adult male Wistar rats were divided into 4 groups: control, HF, culture medium, and CM. All rats, except those in the control group, received an injection of isoproterenol to induce an animal model of HF. The CM group was administered the CM, while those in the culture medium group received standard culture media. Subsequently, serum levels of fibrotic factors, including TGF-β/galectin-3, MCP1, BNP, and ALD, were measured using ELISA. Statistical analysis was performed using one-way analysis of variance and the Tukey test. Results: Serum levels of TGF-β/galectin-3, MCP1, BNP, and ALD were significantly elevated in the HF, CM, and culture medium groups compared with the control group (P<0.001). Additionally, these fibrotic factors were significantly reduced in the CM group compared with the HF group (P<0.001). Notably, CM therapy could not restore TGF-β/galectin-3, MCP1, BNP, or ALD levels to the normal range observed in the control group. Conclusion: Our findings indicate that hAMSCs-CM modulates the expression of inflammatory and fibrotic cytokines, such as TGF-β/galectin-3, MCP1, BNP, and ALD, in isoproterenol-induced HF in male rats. These results contribute to a better understanding of the therapeutic mechanisms underlying hAMSCs-CM treatment for HF. https://jthc.tums.ac.ir/index.php/jthc/article/view/1955

Tehran University of MedicalAuthor> Ailin Talimkhani Department of Physiotherapy, School of Rehabilitation Sciences, Hamadan University of Medical Sciences, Hamadan, Iran. Amin Doosti-Irani Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran. Gholam Reza Hajvalie Department of Physiotherapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran. 2022 10 25 2023 01 09 Background: The long-term effects of aerobic exercise on the cardiorespiratory system have been studied extensively. This study aimed to evaluate the effects of aerobic exercise with and without external loads on blood glucose, cardiovascular, respiratory, and body temperature indices in patients with type II diabetes. Methods: The present randomized control trial recruited participants from the Diabetes Center of Hamadan University through advertisement. Thirty individuals were selected and divided into an aerobic exercise group and a weighted vest group via block randomization. The intervention protocol included aerobic exercise on the treadmill (0 slopes) with an intensity of 50% to 70% of the maximum heart rate. The exercise program for the weighted vest group was identical to that of the aerobic group, except that the subjects wore a weighted vest. Results: The mean age of the study population was 46.77±5.11 years in the aerobic group and 48±5.95 years in the weighted vest group. After the intervention, blood glucose in the aerobic group (167.07±72.48 mg/dL; P<0.001) and the weighted vest group (167.75±61.53 mg/dL; P<0.001) was decreased. Additionally, resting heart rate (aerobic: 96.83±11.86 bpm and vest: 94.92±13.65 bpm) and body temperature (aerobic: 36.20±0.83 ℃ and vest: 35.48±0.46 ℃) were increased (P<0.001). Decreased systolic (aerobic: 117.92±19.27 mmHg and vest: 120.91±12.04 mmHg) and diastolic (aerobic: 77.38±7.54 mmHg and vest: 82.5±11.32 mmHg) blood pressure and increased respiration rate (aerobic: 23.07±5.45 breath/min and vest: 22±3.19 breath/min) were seen in both groups but were not statistically significant. Conclusion: One aerobic exercise session with and without external loads reduced blood glucose levels and systolic and diastolic blood pressure in our 2 study groups. https://jthc.tums.ac.ir/index.php/jthc/article/view/1744 https://jthc.tums.ac.ir/index.php/jthc/article/download/1744/1050

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 18 1 2023 01 30 46 51 Mahsa Nourani Department of Cardiac Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Mehdi Mirzaie Department of Cardiac Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Mohammad Ali Sadr-Ameli Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Amirfarjam Fazelifar Department of Cardiac Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Majid Haghjoo Rajaie CardioVascular Medical and Research Center 2023 01 20 2023 03 11 Background: Electrocardiography (ECG), as an easily accessible modality, is usually helpful in hypertrophic cardiomyopathy (HCM) diagnosis. The purpose of this study was to evaluate the role of ECG in differentiating between obstructive (OHCM) and non-obstructive (NOHCM) HCM. Methods: The present study is a cross-sectional analysis of HCM patients referred to our center between 2008 and 2017. The study variables included age, sex, clinical presentation, medications, and ECG characteristics including PR interval, QRS width, QTc duration, Tpeak-Tend interval, QRS axis, QRS transition, ventricular hypertrophies, atrial abnormalities, ST-T abnormalities, and abnormal Q waves. Results: The HCM sample consisted of 200 patients (55% males; age 45.60±15.50 y) from our HCM database. We compared the clinical and ECG characteristics of 143 NOHCM patients with those of 57 OHCM patients. The OHCM group was significantly younger than the NOHCM group (age =41.7 vs 47.0 y; P=0.016). The initial clinical presentation was similar between the 2 forms (P>0.05), and palpitations were the dominant symptom. Baseline ECG intervals, including PR (155.6 vs 157.9 ms), QRS (82.5 vs 82.0 ms), and QTc (430.5 vs 433.0 ms), were similar (all Ps>0.050). There were no differences regarding baseline rhythm, atrial abnormalities, QRS transition, ventricular hypertrophies, axis changes, ST-T changes, and abnormal Q waves between the HCM groups (all Ps>0.05). Conclusion: The present study showed that standard 12-lead ECG had no role in distinguishing patients with the obstructive and non-obstructive forms of HCM. https://jthc.tums.ac.ir/index.php/jthc/article/view/1797 https://jthc.tums.ac.ir/index.php/jthc/article/download/1797/1051

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 18 1 2023 01 30 52 61 Mahnaz Solhi Health Promotion Research Center, Iran University of Medical Sciences, Tehran, Iran Zohreh Abbasi Department of Health Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Mahboobeh Rasouli Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Nasim Naderi Department of Heart Failure and Transplantation, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. 2022 08 16 2023 01 09 Background: Hypertension is a health problem. The purpose of the present study was to compare perceived self-efficacy, benefits, and barriers of hypertension control between male and female patients. Methods: This cross-sectional study was carried out on 400 patients referred to Rajaie Cardiovascular Medical and Research Center in Tehran from August 2020 through March 2021. The convenience sampling method was used. The data collection tools consisted of a digital sphygmomanometer, a demographic form, and a researcher-made questionnaire of perceived benefits, barriers, and self-efficacy of hypertension control, whose validity and reliability were obtained. Results: The mean age of the male and female patients was 54.02±12.93 years and 56.48±12.10 years, respectively. The mean score of perceived barriers in women was lower than that in men, and the mean perceived self-efficacy in women was higher than that in men (P<0.001). According to the regression test, history of smoking in men and family history of hypertension and age in women were predictors of perceived benefits. Further, occupation and history of smoking in men and education level, family history of hypertension, and history of smoking in women were predictors of perceived barriers. Additionally, marital status, education level, and disease duration in men and education level, family history of hypertension, history of smoking, and age in women were predictors of perceived self-efficacy (P<0.050). Conclusion: In men, the mean score of perceived barriers was higher and the mean score of perceived self-efficacy was lower. Additionally, the predictors of each of these perceptions were determined. https://jthc.tums.ac.ir/index.php/jthc/article/view/1704 https://jthc.tums.ac.ir/index.php/jthc/article/download/1704/1052

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 18 1 2023 01 30 62 67 EN Azam Kiani Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Razieh Omidvar Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Nasim Naderi Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Sepideh Taghavi Heart Valve Disease Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Marzieh Mirtajaddini Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. 2022 11 13 2023 03 15 Background: Long-term outcomes in patients with idiopathic pulmonary arterial hypertension (IPAH) treated with calcium channel blockers (CCBs) are not well documented. Therefore, this study aimed to determine the long-term response to treatment with CCBs in patients with IPAH. Methods: This retrospective cohort study was performed on 81 patients with IPAH admitted to our center. Vasoreactivity testing with adenosine was performed. Twenty-five patients showed a positive response and were included in the analysis. Results: Of 24 patients, 20 (83.3%) were female, and the mean age of the patients was 45.90±10.42 years. Fifteen patients improved after 1 year on CCB therapy (the long-term CCB responders group), and 9 showed no improvement (the CCB failure group). The CCB responders group had a greater proportion of patients in the New York Heart Association (NYHA) functional class I or II (93.3%), a longer distance walked, and less severe hemodynamic parameters. At the 1-year evaluation, the long-term CCB responders showed more improvements in the mean 6-minute walk test result (437.43±125.32 vs 268.17±130.06; P=0.040), the mixed venous oxygen saturation level (71.84±9.87 vs 59.03±9.95; P=0.041), and the cardiac index (4.76±1.12 vs 3.15±0.90; P=0.012). Additionally, mPAP was lower in the long-term CCB responders group (47.35±12.70 vs 67.23±14.08; P=0.034).  Finally, all the CCB responders were in the NYHA functional class I or II (P=0.001). Conclusion: Our study illustrated that long-term treatment with oral CCBs was effective in 60% of acute responders and 18.5% of the entire study population. https://jthc.tums.ac.ir/index.php/jthc/article/view/1756 https://jthc.tums.ac.ir/index.php/jthc/article/download/1756/1053

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 18 1 2023 01 30 68 71 EN Mohammadamin Emami Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Sara Mirzamohamadi Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Amirhossein Heidari Cardiac Primary Prevention Research Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran Afsaneh Aein Cardiac Primary Prevention Research Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran Mojtaba Salarifar Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Ebrahim Nematipour Tehran Heart Center 2022 12 04 2023 04 02 Background: Coronary artery disease (CAD) is the leading cause of cardiovascular death globally, and the most severe form of CAD, ST-elevation myocardial infarction (STEMI), needs immediate treatment. This study aimed to report patient characteristics and the causes of door–to–balloon time (D2BT) delays in STEMI patients admitted to Tehran Heart Center with a D2BT exceeding 90 minutes. Methods: This cross-sectional study was conducted at Tehran Heart Center, Iran, from March 20th, 2020, through March 20th, 2022. Variables consisted of age, sex, diabetes mellitus, hypertension, dyslipidemia, smoking, opium, family history of CAD, in-hospital mortality, primary percutaneous coronary intervention results, culprit vessels, causes of delays, the ejection fraction, triglycerides, and low and high-density lipoprotein levels. Results: The study population was composed of 363 patients (272 males [74.9]) at a mean (SD) age of 60±11.47 years. The leading causes of D2BT delays were the catheterization lab used in 95 patients (26.2) and misdiagnosis in 90 (24.8). Other causes were ST-elevation less than 2 mm in electrocardiograms in 50 patients (13.8) and referral from other hospitals in 40 (110.). Conclusion: The catheterization lab in use and misdiagnosis were the leading causes of D2BT delays. We recommend that high-volume centers allocate an additional catheterization lab with an on-call cardiologist. Improved resident training and supervision in hospitals with many residents are also necessary. https://jthc.tums.ac.ir/index.php/jthc/article/view/1767 https://jthc.tums.ac.ir/index.php/jthc/article/download/1767/1056

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 18 1 20