QTc Values Research Articles

Repolarization in systemic sclerosis: a meta-analysis.

Systemic sclerosis (SSc) is a rare connective tissue disease characterized by immune dysregulation, vascular damage, and increased deposition of extracellular matrix. In SSc, cardiac manifestations are common and account for 14% of deaths. Numerous studies have examined electrocardiographic findings in SSc patients yielding conflicting reports regarding QTc duration. We conducted a systematic review and meta-analysis of existing studies to investigate whether QTc duration may aid in diagnosis and risk stratification of SSc patients. Two electronic databases (PubMed and Embase) were searched for case-control and cohort studies assessing QTc duration in SSc patients published before March 1, 2021. A random-effects model was used to meta-analyze the results, and included studies were tested for heterogeneity. Linear regression was performed to determine correlations between comorbidities, and QTc duration. Ninety-six studies, abstracts, and posters were identified. After abstract review and duplicate removal, 23 manuscripts remained. After application of the inclusion and exclusion criteria, 10 studies remained which were quantitatively analyzed. The weighted mean QTc was found to be 422.21ms for SSc patients and 411.43ms for control subjects. A significant increase in QTc duration among SSc patients was found, with a standardized mean difference of 0.59 (p < 0.01, 95% CI 0.27-0.92). No significant correlation was found between underlying traits and QTc values. Substantial heterogeneity was found between the studies (I2 = 83%, p < 0.01). A significant increase in QTc duration is observed in SSc patients, though the absolute prolongation is not extreme. Therefore, the clinical utility of this finding is unclear and merits large prospective observations. Key Points • A statistically significant prolongation of the QTc interval exists in patients with systemic sclerosis. • Absolute QTc differences between healthy controls and scleroderma patients are not extreme, and, as such, may be of limited clinical utility. • When assessing the underlying traits of systemic sclerosis patients, no statistically significant correlations were found between underlying parameters and QTc duration.

Relationship between a Prolonged Corrected QT Interval and Mortality in Patients Presenting with Syncope at the Emergency Department.

Background Syncope is a common symptom in emergency department patients. Among various etiological factors, cardiac causes have the highest risk of mortality. The corrected QT interval is considered an independent predictor of mortality for many diseases. Objectives Analyze QT interval analysis of patients presenting to the emergency department with syncope. Methods In this prospective observational study, patients who presented to the emergency department with syncope between January 1, 2018, and January 1, 2019 were included. Results The median age was 64 (49-78) years, and 58.8% of patients were male. The corrected QT interval (QTc) in patients with coronary artery disease and chronic obstructive pulmonary disease was longer than those without. There was no statistically significant association between hypertension, diabetes, stroke, thyroid disease, and prolonged QTc. Patients who did not survive had significantly prolonged QT intervals. According to ROC analysis, sensitivity of >440.5 ms QTc values in predicting mortality was 86% and specificity was 71% (AUC = 0.815; 95%CI = 0.71 − 0.91; p < 0.001). Conclusions Patients admitted to emergency department with syncope and a prolonged QTc are associated with a higher mortality rate and thus can provide us with an important guide for the management of these patients.

Abstract 14277: Diagnostic Accuracy of the 12-lead Electrocardiogram in the First 48 Hours of Life in Neonates From a Parent With Genotype Positive Long QT Syndrome

Introduction: Long QT syndrome (LQTS) is an autosomal dominant disorder characterized by a prolonged QT interval on a 12-lead electrocardiogram (ECG). Cascade genetic testing for LQTS is standard of care, including in infants, but takes 2-4 weeks for return of results. For newborns of parent with confirmed LQTS, the ECG is obtained after birth as an initial assessment, but QTc values during the immediate newborn period may be misleading. Thus, our objective was to determine the ECG’s diagnostic accuracy in the first 48 hours of life for neonates born to a parent with LQTS. Methods: We performed a retrospective review of the electronic medical records of neonates born to a parent with ≥ 1 pathogenic variant in a LQTS-causative gene for which at least 1 ECG in the first 48 hours of life was obtained. Clinical data was collected on all neonates with focus on the 12-lead ECG, family history, and genetic testing results. The sensitivity and specificity of the diagnostic ECG were calculated using QTc thresholds of 440, 460, and 470 ms. Results: Overall, 70 infants (35 [50%] females) met inclusion criteria and the mean QTc on the first ECG was 484 ± 61 ms. Following genetic testing, a LQTS-causing variant was identified in 46 infants (66%), including 22 (48%) with LQT1 ( KCNQ1 ), 12 (26%) with LQT2 ( KCNH2 ), and 8 (17%) with LQT3 ( SCN5A ). Mean QTc in the first 48 hours of life for neonates that ultimately were genotype-positive was 502 ± 59 ms compared to 451 ± 50 ms (p &lt; 0.001) for genotype-negative neonates. When using a recommended threshold QTc of ≥ 440 ms, 6/46 genotype-positive neonates (13%) were missed (underdiagnosed) and 13/24 genotype-negative neonates (54%) were overdiagnosed (sensitivity: 87%, specificity: 45%). At a QTc threshold ≥ 460 ms, 15 (21%) were classified erroneously (sensitivity: 85%, specificity: 67%) while at a threshold of ≥ 470 ms, 18 (26%) were misclassified (sensitivity: 76%, specificity: 71%). Conclusions: Although a baseline ECG should still be obtained before a newborn’s dismissal, reliance solely on the QTc for diagnosing LQTS and initiating therapy will result in an unacceptable number of misclassifications. Thus, genetic testing must be initiated prior to the baby’s discharge and proper anticipatory guidance is vital while awaiting genetic test results.

Abstract 9536: Prediction of Drug-Induced QTc Prolongation With an ECG Based Machine Learning Model

Introduction: Initiation of QTc-prolonging medications may lead to the rare but potentially catastrophic event, torsades de pointes (TDP). At present, no adequate, generalizable tools exist to predict drug-induced long QTc (LQT); machine learning from ECG data is a promising approach. Hypothesis: Prediction of drug-induced LQT using an ECG-based machine learning model is feasible, and outperforms a model trained on baseline QTc, age, and sex alone. Methods: We identified baseline 12-lead ECGs with QTc values &lt; 500 ms for patients who had not received any known, conditional, or possible QTc prolonging medication per CredibleMeds at the time of ECG or within the past 90 days. We matched these with ECGs from the same patients while they were taking at least one CredibleMeds drug (“on-drug” ECGs). Using 5-fold cross-validation, we trained and tested two machine learning models using the baseline ECGs of the 92,848 resulting pairs to predict drug-induced LQT (≥500 ms) in the on-drug ECGs: a deep neural network using ECG voltage data, and a gradient-boosted tree using the baseline QTc. Age and sex were also inputs to both models. Results: On-drug LQT prevalence was 16%. The ECG model demonstrated superior performance in predicting on-drug LQT (area under the receiver operating characteristic curve (AUC) = 0.756) compared to the QTc model (0.710). At a potential operating point (Figure), the ECG model had 89% sensitivity and 95% negative predictive value. Even in the subset of patients with baseline QTc &lt; 470/480 ms (male/female; post-drug LQT prevalence = 14%), the ECG model demonstrated good performance (AUC = 0.736). Conclusions: An ECG-based machine learning model can stratify patients by risk of developing drug-induced LQT better than a model using baseline QTc alone. This model may have clinical value to identify high-risk drug starts that would benefit from closer monitoring and others who are at low risk of drug-induced LQT.

Abstract 13067: Recapitulating Long QT Syndrome Phenotype in Induced Pluripotent Stem Cells-Derived Cardiomyocytes Using CRISPR/Cas9 Technology

Introduction: Long QT syndrome (LQTS) is an inherited arrhythmia syndrome with a hallmark of QT prolongation secondary to delayed repolarization of cardiomyocytes (CM) on 12-lead ECG. Hypothesis: Studying LQTS in an induced pluripotent stem cell (iPSC)-derived CM model allows for patient-specific phenotype characterization in vitro . We report such a strategy (fig. A) in a patient with LQT type 3 (ECG QTc 503 msec) who harbored a heterozygous pathogenic variant in SCN5A (c.1231G&gt;A), and in a healthy control for comparison (ECG QTc 388 msec). Methods: IPSCs were generated from patient and control dermal fibroblasts using a non-integrational Sendai reprogramming method. The patient’s SCN5A (c.1231G&gt;A) variant was edited into the healthy control using CRISPR/Cas9 technology. CM were subsequently differentiated and beating CM clusters were seeded onto Maestro CytoView multi-electrode array plates. Serial corrected field potential duration (FPD) measurements (n=12), equivalent to QTc values on ECG, were recorded on days 24 to 39 of CM differentiation per sample. CM were exposed to varying concentrations of Nifedipine and Sotalol through cell culture media exchange. Paired t-tests (non-parametric) were utilized for p&lt;0.05. Results: Reprogrammed iPSCs displayed pluripotency characteristics (fig.B). IPSC-derived CMs had confirmed cardiac lineage (fig. C). Prolonged FPD values, corrected for beating rate, were observed in both the LQT3 patient-derived iPSC-CMs (p&lt;0.0001) and the genetically induced LQT3 iPSC-CMs (p&lt;0.0001) compared to control (fig. D &amp; E). Nifedipine and sotalol altered FPD in a dose-dependent response (fig. F &amp; G). Conclusions: An iPSC-derived CM model reliably recapitulates the phenotype of LQTS. Induced LQT3 iPSC-CMs genetically edited from a healthy control accurately recapitulate the LQT3 disease phenotype. Drug effects on CM repolarization were demonstrable in the iPSC-CM model.

The effect of oral ondansetron on QT interval in children with acute gastroenteritis; a retrospective observational study

BackgroundIn mildly to moderately dehydrated patients with acute gastroenteritis (AGE), oral rehydration therapy (ORT) is the treatment of choice. Though ondansetron is a very effective antiemetics and leads to succeed ORT, there have been reports QT prolongation in patients using it. We investigated the effect of oral ondansetron on QT interval in mildly to moderately dehydrated children with AGE.MethodsThis retrospective observational study was conducted in a single pediatric emergency department (ED) of a tertiary university hospital. We collected the medical records of patients with a primary diagnosis of AGE who received oral ondansetron and underwent an electrocardiogram between January 2017 and June 2018. A pediatric emergency physician calculated the corrected QT interval (QTc) by Bazett’s method, and the calculations were reviewed by a pediatric cardiologist. QTc values before (preQTc) and after (postQTc) ondansetron administration were analyzed. ΔQTc was calculated as the change from preQTc to postQTc. We also investigated any cardiac complications from oral ondansetron.ResultsTotal 80 patients were included. The mean age of the patients was 53.31 ± 32.42 months, and 45% were male. The mean dose of oral ondansetron was 0.18 ± 0.04 mg/kg. The mean interval from administration of ondansetron to performance of the electrocardiogram was 65 ± 26 min. The mean preQTc was 403.3 ± 24.0 ms, and the mean postQTc was 407.2 ± 26.7 ms. Two patients had a preQTc ≥460 ms, and one patient had a postQTc ≥460 ms. ΔQTc was ≥30 ms in seven patients (8.8%). No ΔQTc was ≥60 ms. No pre- or postQTc was ≥500 ms. No patient had a fatal cardiac arrhythmia after taking ondansetron.ConclusionOral administration of a single dose of ondansetron in children with AGE did not cause high-risk QTc prolongation or fatal arrhythmia.

Safety of Chloroquine or Hydroxychloroquine Plus Azithromycin for the Treatment of COVID-19 Patients in Burkina Faso: An Observational Prospective Cohort Study.

IntroductionThough chloroquine derivatives are used in the treatment of coronavirus disease 2019 (COVID-19) in many countries worldwide, doubts remain about the safety and efficacy of these drugs, especially in African communities where published data are scarce.MethodsWe conducted an observational prospective cohort study from April 24 to September 03, 2020, in Burkina Faso to assess (as primary outcome) the clinical, biological, and cardiac (electrocardiographic) safety of chloroquine or hydroxychloroquine plus azithromycin administered to COVID-19 patients. The main secondary outcomes were all-cause mortality and median time of viral clearance.ResultsA total of 153 patients were enrolled and followed for 21 days. Among patients who took at least one dose of chloroquine or hydroxychloroquine (90.1% [138/153]), few clinical adverse events were reported and were mainly rash/pruritus, diarrhea, chest pain, and palpitations. No statistically significant increase in hepatic, renal, and hematological parameters or electrolyte disorders were reported. However, there was a significant increase in the QTc value without exceeding 500ms, especially in those who received chloroquine phosphate. Three adverse events of special interest classified as serious (known from chloroquine derivatives) were recorded namely pruritus, paresthesia, and drowsiness. One case of death occurred. The average onset of SARS-CoV-2 PCR negativity was estimated at 7.0 (95% CI: 5.0–10.0) days.ConclusionHydroxychloroquine appeared to be well tolerated in treated COVID-19 patients in Burkina Faso. In the absence of a robust methodological approach that could generate a high level of scientific evidence, our results could at least contribute to guide health decisions that should be made based on different sources of scientific evidence including those from our study.

Изменение величины интервала QT на различных этапах периоперационного периода у пациентов с ишемической болезнью сердца в условиях общей анестезии

Objective. To evaluate the status of QT interval derivatives in patients with chronic IHD during different perioperative periods of planned open cholecystectomy under general anaesthesia and to determine the possibility of using meldonium for prevention of QT interval dysfunction. Materials and methods. Patients with the diagnosis of cholelithiasis with verified forms of chronic CHD (angina I and II AC) were divided into 2 groups: Group 1 was the control group with conventional perioperative therapy, and Group 2 was the main group with additional meldonium. The dynamics of the corrected QT interval (QTc) and the variance of the QT interval (DQT) were assessed. Analysis was performed by means of daily Holter ECG monitoring, in which 6 time periods were singled out: 1 - the day before the operation (18 hours); 2 - hours before the operation; 3 - induction into anesthesia; 4 - maintenance of anesthesia; 5 - withdrawal from anesthesia; 6 - the day 2 after the operation (18 hours). Results. The increase in QTc and DQT values during induction, maintenance and withdrawal from anesthesia was detected only in the control group. The inclusion of meldonium in perioperative therapy in patients with CHD was accompanied by the absence of QTc interval prolongation and an increase in DQT values in the periods of induction, exit and maintenance of anaesthesia. Conclusion. The perioperative period was accompanied by a prolongation of the QTc interval and an increase in DQT values in the group receiving conventional therapy. The inclusion of meldonium was accompanied by no increase in QTc and DQT during most follow-up periods.

Performance of Automated Telemetry in Diagnosing QT Prolongation in Critically Ill Patients.

QT prolongation increases the risk of ventricular arrhythmia and is common among critically ill patients. The gold standard for QT measurement is electrocardiography. Automated measurement of corrected QT (QTc) by cardiac telemetry has been developed, but this method has not been compared with electrocardiography in critically ill patients. To compare the diagnostic performance of QTc values obtained with cardiac telemetry versus electrocardiography. This prospective observational study included patients admitted to intensive care who had an electrocardiogram ordered simultaneously with cardiac telemetry. Demographic data and QTc determined by electrocardiography and telemetry were recorded. Bland-Altman analysis was done, and correlation coefficient and receiver operating characteristic (ROC) coefficient were calculated. Fifty-one data points were obtained from 43 patients (65% men). Bland-Altman analysis revealed poor agreement between telemetry and electrocardiography and evidence of fixed and proportional bias. Area under the ROC curve for QTc determined by telemetry was 0.9 (P < .001) for a definition of prolonged QT as QTc ≥ 450 milliseconds in electrocardiography (sensitivity, 88.89%; specificity, 83.33%; cutoff of 464 milliseconds used). Correlation between the 2 methods was only moderate (r = 0.6, P < .001). QTc determination by telemetry has poor agreement and moderate correlation with electrocardiography. However, telemetry has an acceptable area under the curve in ROC analysis with tolerable sensitivity and specificity depending on the cutoff used to define prolonged QT. Cardiac telemetry should be used with caution in critically ill patients.

Empagliflozin significantly prevents QTc prolongation due to amitriptyline intoxication via intracellular calcium regulation

Abstract Background Empagliflozin is a SGLT-2 inhibitor used in the treatment of Type 2 diabetes and has positive effects on cardiovascular outcomes. Amitriptyline can be used in many clinical indications but leads to cardiotoxicity by causing QT prolongation. Aim Our aim in the present study is to observe the effect of the concomitant use of amitriptyline and empagliflozin together, which have an effect on sodium and calcium balance in myocytes, on QTc by using ECG. Materials and methods Twenty-four male Wistar-Albino rats were randomized into four groups. The control group received only serum physiologic (1ml) via orogastric gavage (OG). The EMPA group received empagliflozin (10 mg/kg) via OG. The AMT group received amitriptyline (100 mg/kg) via OG. The AMT+EMPA group (n: 6) received amitriptyline and empagliflozin at same dose. Under anesthesia; QT and QTC intervals were measured at baseline, first, and second hours. Results The differences in QT and QTc values between the AMT group and control group were observed from the 1nd hour (Table 1, Figure 1). It was detected that the measurements of the control group were within normal limits. In the control group, QT was 77.33±9.02 ms at the basal, 73.50±2.26 ms at the 1st hour, 78.17±6.18 ms at the 2nd hour. QTc calculation was 165.42±18.34±10.5 ms at the basal, 166.63±17.92 msat the 1st hour, 184.65±12.86 ms at the 2nd hour. ECG findings of the EMPA group were within normal limits and similar to the control group (Table 1). The durations of QT interval and QTc calculations were found to be statistically longer in the AMT group than the control group at the 1st and 2nd hour (p≤0.001). Empagliflozin significantly ameliorated AMT-induced QT and QTc prolongation. The durations of QT interval were significantly lower at first (p&amp;lt;0,001) and 2nd hours (p&amp;lt;0.01) in the AMT+EMPA group compared to the AMT group. Moreover, QTc calculation was significantly lower in the AMT+EMP group than the AMT group at 1st and 2nd hour (P&amp;lt;0.01) (Table 1). Electrocardiographic comparisons of all groups for one second within the second hour can be seen in Figure 2. Conclusion In the present study, we have detected that empagliflozin significantly ameliorates amitriptyline induced QT prolongation. This effect is probably due to the opposite effects of these two agents in the intracellular calcium balance. It's known that; toxic dose of amitriptyline increases the amount of Sarcoplasmic Ca and the calcium permeability of Ryanodine channels, decreases SERCA-mediated Ca-reuptake by decreasing the calcium binding capacity of calsequestrin, and these leads QTc prolongation. It has been shown that empagliflozin increases Ca reuptake by causing a significant increase in SERCA activity, and decreases Ca sparks by causing inhibition of Ryanodine activity. With more clinical trials, the routine use of empagliflozin may be suggested to prevent QTc prolongation in the diabetic patients receiving amitriptyline. Funding Acknowledgement Type of funding sources: None. Table 1. QT, QTc durations and HR for groupsFigure 1. ECG traces – a: CON, b: EMPA, c: AMT, d: AMT+EMP

Emotional and cardiovascular health: the impact of depression on cardiac autonomic activity

Abstract Background The coexistence of depression and cardiovascular diseases is frequently accompanied by an increased risk of adverse outcomes. QTc, an indicator of ventricular depolarization and cardiac autonomic activity, has been proposed as a biomarker of this interplay. Purpose We aimed to investigate the possible association of depression with QTc interval. Methods Assessment of depressive symptoms was performed in 1637 participants of the cross-sectional Corinthia study with the Zung self-rating depression scale in those younger than 65 years of age (Group 1) and with the geriatric depression scale in elderly individuals (&amp;gt;65 years, Group 2). Moreover, electrocardiogram was performed and measurement of the QT interval was derived after correction for heart rate (QTc) using the Bazett's formula. Abnormal QTc was present when QTc duration exceeded 440 ms. Results Group 1 individuals classified as having depression had longer QTc duration (No depression: 389.3±27.0 ms vs. Depression: 401.1±32.9 ms, p&amp;lt;0.001) and percentage of abnormal QTc (No depression: 2.0% vs. Depression: 10.8%, p=0.001) (Figure 1, Panels A and B). Elderly individuals had similar values of QTc (No depression: 409.9±29.6 ms vs. Depression: 405.2±46.4 ms, p=0.37) and percentage of abnormal QTc (No depression: 13.2% vs. Depression: 12.3%, p=0.78) irrespective of depression status (Figure 1, Panels C and D). The presence of depression in Group 1 subjects was associated with an increased QTc- by 10.8 ms and with an approximately 7-fold higher prevalence of abnormal QTc duration, even after adjustment for confounders (). Such finding was not detected in elderly individuals (Figure 1, Panel F). Conclusion Depression might adversely affect ventricular repolarization especially in middle-aged subjects. These findings highlight the interrelationship between emotional and cardiovascular health and the role of depression as a cardiovascular risk factor. Funding Acknowledgement Type of funding sources: None. Figure 1

Serum Osteoprotegerin Level as a Risk Factor for Atherosclerosis in Systemic Lupus Erythematosus Patients: A Cross Sectional Study

Background: Prediction ofthe risk of atherosclerosis in Egyptian patients with systemic lupus erythematosus (SLE) by measuring serum osteoprotegerin (OPG) level and correlation between OPG levels and SLE disease activity (assessed by Systemic Lupus Erythematosus Disease Activity Index [SLEDAI] score), is the aim of this study. Methods:A cross sectional study in which all patients were subjected to full medical history, full clinical examination (with special emphasis to SLE symptoms and signs e.g. photosensitivity, arthralgia, arthritis, malar rash, blood pressure and lower limb edema), laboratory investigations (CBC, random blood sugar [RBS], ESR, albumin/creatinine ratio, serum urea and creatinine, serum albumin, C3, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, calcium and phosphorus). Electrocardiography (ECG) was done to calculate QTc interval using Bazett’s formula: QTC = QT / √ RR. Serum osteoprotegerin level was measured using ELISA technique. All participants were subjected to imaging in the form of: Carotid duplex: to assess intima-media thickness just two cm before carotid bifurcation, and to assess any plaques, if present. Also brachial artery flow mediated dilatation method: for detection of subclinical atherosclerosis. Results: There was a statistically significant negative correlation between serum levels of osteoprotegerin and brachial flow mediated dilation percentage (FMD %) values (P value &gt; 0.001) which means a significant correlation between high serum OPG levels and subclinical atherosclerosis in SLE patients. There were statistically significant differences between SLE cases and controls in right and left carotid intima-media thickness (P value: 0.034 &amp; 0.036 respectively), serum osteoprotegerin levels (P value: &gt; 0.001) and QTc values (P value: 0.011) which were all statistically significantly higher in SLE patients, while brachial FMD % was statistically significantly lower in SLE patients than in controls (P value: &gt; 0.001). Also, there was a statistically significant positive correlation between serum OPG levels and QTc interval (P value: 0.006). Conclusion: We have concluded that serum OPG level has a significant correlation with subclinical atherosclerosis and endothelial dysfunction, which was measured by CIMT and brachial mediated flow dilation method.

Protocol-based cardiotoxicity monitoring in hydroxychloroquine medicated COVID-19 pediatric patients

Introduction/objectivesBy May 2020, SARS-CoV-2 had caused more than 400 000 deaths worldwide. Initially, hydroxychloroquine was a treatment option for COVID-19. More recent studies have questioned its safety and efficacy and, until stronger evidence is available, it was suspended from therapy protocols. We describe our experience treating COVID-19 Portuguese pediatric patients with hydroxychloroquine, having applied a protocol for monitoring cardiac toxicity. MethodsAn observational retrospective study of COVID-19 pediatric patients, admitted from March to April 2020 and treated with hydroxychloroquine. Cardiotoxicity was assessed using ECG recordings and corrected QT-time (QTc). Patients were classified into risk-groups depending on QTc value: normal, slightly elevated or severely elevated (>500 ms). ResultsTotal of 14 patients, with a median age of 10 years [four months; 17 years], treated with hydroxychloroquine for a median of five days. Hydroxychloroquine was used in monotherapy in six patients (mainly mild disease with comorbidities), and in association with lopinavir/ritonavir (3) and azithromycin (5) in moderate to severe disease. Other QT-prolonging therapies were used in five patients: oseltamivir (3), omeprazole (1), morphine (1) and ketamine (1). At 48 hours of treatment, two patients temporarily suspended hydroxychloroquine due to QTc prolongation (>500 ms). All patients completed the whole treatment. No other side effects or deaths occurred. ConclusionClinical trials are evolving to define hydroxychloroquine effectivity and safety. Our considerable pediatric population supports the need for cardiotoxicity monitoring during therapy but suggest its use seems to be safe in COVID-19 pediatric patients, even in association with other QT-prolonging therapies.

The relationship between QT interval and pain severity in trauma patients in the emergency department

Aim: Cardiac depolarization occurs in patients experiencing pain from acute traumas, and changes in QT interval could indicate the state of ventricular depolarization. Thus, we aimed to determine the relationship between pain severity and QT interval in patients experiencing acute trauma. Material and Method: Seventy patients, who were conscutively- admitted to the Emergency Department due to moderate or severe trauma (study group), and sixty healthy individuals (control group) were included in this study. The QT interval was calculated for each group before and after analgesia and visual analog scale pain levels were recorded. Statistical analyses were performed using SPSS for Windows software (ver. 21.0; SPSS Inc., Chicago, IL, USA). Data are presented as medians±interquartile range (IQR). Statistical significance was determined using Mann-Whitney U, Wilcoxon, and chi-square tests, with a p-value &lt;0.05 considered significant. Results: The mean age of patients with trauma and control patients was 31.50±25 years and 35.00±20 years, respectively. Among trauma patients, QT, RR and corrected QT (QTc) intervals were significantly different before and after analgesia (P&lt;0.001). Similarly, the average pre-analgesia QT, RR and QTc values also differed between pre- and post-analgesia trauma patients (p=0.007, p&lt;0.001, and p&lt;0.001, respectively). However, no differences in QT values were observed before and after analgesia between patients experiencing moderate versus severe pain (p&gt;0.05). Conclusion: In trauma patients, acute pain prolonged the QT interval, which reverted to normal following the administration of nonsteroidal anti-inflammatory drugs. However, additional comparative studies on this topic are required.

Relationship between ECG Findings and Serum Biomarkers in COVID-19 Patients

Abstract Background and aim: The aim of this study was to evaluate the relationship between ECG findings and blood parameters indicative of inflammation and myocardial injury in COVID-19 patients. Methods: The study included 159 females and 194 males. Demographics, ECG findings (axis, rhythm, branch block, ST- and T-wave changes, premature ventricular contractions, early repolarization, S1Q3T3, fragmented QRS [fQRS], rate, PR, QRS, QT interval, QTc, P-wave dispersion) and albumin, D-dimer, ferritin, pro-BNP, procalcitonin, protein, troponin T, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein/albumin ratio (CAR) were recorded. Results: In the study, 45% of the cases were female and 55% were male. The mean age of the included patients was 45.7 ± 24.4 years. The most frequent comorbidities were chronic obstructive pulmonary disease (COPD) and hypertension (HT) in both groups. The incidence of fQRS on the 1st day was significantly higher in patients with negative COVID-19 test (23% for positive RT-PCR versus 35.6% for negative RT-PCR, p = 0.016). QTc values on the 3rd and 5th day were significantly higher in patients with negative RT-PCR (p = 0.045 and p = 0.042, respectively). Albumin and procalcitonin were significantly higher in patients with positive COVID-19 test results (p = 0.018 and p &lt;0.001, respectively). Patients with fragmented QRS presented significantly lower serum albumin (40.62 ± 4.73 g/L vs. 42.92 ± 3.72 g/L, p = 0.01), and protein levels (p = 0.02), as well as lower lymphocyte count, and significantly higher levels of C-reactive protein (47.01 ± 65.01 mg/L vs. 24.55 ± 44.17 mg/L, p = 0.001), D-dimer (p = 0.009), neutrophil count, pro-BNP (p = 0.004), troponin T (p &lt;0.001), NRL and CAR (1.28 ± 1.83 versus 0.6 ± 1.11, p &lt;0.001). Conclusion: Patients with COVID-19 infection presented significantly higher levels of C-reactive protein, D-dimer, neutrophil, pro-BNP, procalcitonin, troponin T, NLR, and CAR, and significantly lower levels of albumin, lymphocyte count, and serum proteins, indicating the level of inflammation and its relationship with myocardial injury. Further follow-up studies are required, on larger patient sets, for the development of risk prediction tools in COVID-19 patients.

Yaşlılarda Levofloksasin Kullanımının Güvenliliği

Aim: Levofloxacin is one of the most prescribed antibacterial agents. They are used for the treatment of many infections, which are of paramount importance for geriatric practice. In this study, we aimed to investigate the safety of levofloxacin, which provides many advantages in older patients. Material and Methods: The medical records of 92 older patients admitted to the geriatric clinic and treated with levofloxacin for any reason were retrospectively reviewed. Demographic characteristics, drugs, electrocardiography parameters, Apathy Evaluation Scale score, and delirium evaluated by Confusion Assessment Method were recorded on the baseline and the third day. We also recorded 21 patients’ seventh-day data, which can be available. All the patients or caregivers were questioned about tendinitis or tendon rupture within 90 days after treatment at the outpatient controls. Results: The mean age of the patients was 80.75±7.01 years, and 57.6% were female. There was a significant difference between baseline and third day QT (p:0.008) and QTc (p&amp;lt;0.001) values, but on the 7th day, not (p&amp;gt;0.05). Delirium and Apathy Evaluation Scale scores improved during the treatment (p&amp;gt;0.05). No patient had a seizure. Tendinitis and tendon rupture were not detected during or within the three months after the treatment. Conclusion: In the light of these results, the use of levofloxacin seems to be safe in older adults, with caution on additional risk factors.

ECG INTERPRETATION AMONG COVID-19 PATIENTS

Background: The goal was to use surface electrocardiographic (ECG) indicators to detect COVID-19's malignant arrhythmic potential.&#x0D; Methodology: In 51 COVID-19 patients and 40 control subjects, the ECG parameters PR, QT, QTc, QTd, TPe, and Tpe/QTc were assessed. COVID-19 patients had substantially higher mean QTc (410.8 24.3 msec vs. 394.6 20.3 msec, p.001), Tpe/QTc (0.19 0.02 vs. 0.18 0.04, p =.036), and median QTd (47.52 vs. 46.5) values than the control group. Troponin levels were linked with heart rate (r = 0.387, p =.006) but not with ECG parameters (r = 0.387, p =.006).&#x0D; Conclusion: In Covid19 patients, several ventricular arrhythmia surface ECG predictors, such as QTc, QTd, and Tpe/QTc, are elevated. Because drugs used in COVID-19 patients have the potential to impact these parameters.&#x0D; Keywords: Malignant arrhythmia, COVID-19, QT prolongation ECG.

B-PO05-149 ASSESSMENT OF DRUG-INDUCED QT PROLONGATION USING AN AI-ECG ALGORITHM ON A MOBILE 6-LEAD ECG PLATFORM

The ability of an artificial intelligence (AI)/deep neural network (DNN)-derived algorithm to assess the QT interval has been trained, validated, and tested recently in a large cross-sectional population study. This AI/DNN-derived QTc has been tested prospectively in nearly 700 patients with possible congenital long QT syndrome (LQTS) using recordings obtained on a 6-lead (6L) mobile device. We sought to evaluate the ability of a mobile 6L device to detect clinically meaningful drug-induced QT prolongation has not been assessed. We obtained coincident standard 12-lead ECGs (12L, supine) and mobile 6L recordings (seated and supine) from patients who were hospitalized for initiation of a class III antiarrhythmic drug (dofetilide or sotalol) for the treatment of atrial fibrillation (AF). Baseline and 2-hour post-dose recordings were performed during initiation for a total of 5 doses. We examined the correlation between the Bazett’s heart rate corrected QTc values obtained on the standard 12L and the mobile 6L devices. Among the 23 patients (mean age 60 ± 13 years, 74% male; n=16; receiving dofetilide, n=7 receiving sotalol), 192 12L recordings and 551 6L recordings were performed. The calculated 12L QTc values ranged from 300 milliseconds to 552 milliseconds. There was good correlation between 12L and 6L values (r=0.92) regardless of underlying rhythm (r=0.91 for recordings during AF and 0.91 during sinus rhythm), and regardless of body position during the 6L recording (r=0.92 for seated position and for the supine position). A mobile 6L device performs well for the assessment of QTc during antiarrhythmic drug initiation.

Early Identification of Prolonged QT Interval for Prevention of Sudden Infant Death.

Introduction: Long QT syndrome is the main arrhythmogenic disease responsible for sudden death in infants, especially in the first days of life. Performing an electrocardiogram in newborns could enable early diagnosis and adoption of therapeutic measures focused on preventing lethal arrhythmogenic events. However, the inclusion of an electrocardiogram in neonatal screening protocols still remains a matter of discussion. To comprehensively analyse the potential clinical value of performing an electrocardiogram and subsequent follow-up in a cohort of newborns.Methods: Electrocardiograms were performed in 685 neonates within the first week of life. One year follow-up was performed if QTc > 450 ms identified. Comprehensive genetic analysis using massive sequencing was performed in all cases with QTc > 470 ms.Results: We identified 54 neonates with QTc > 450 ms/ <470 ms; all normalized QTc values within 6 months. Eight cases had QTc > 480 ms at birth and, if persistent, pharmacological treatment was administrated during follow-up. A rare variant was identified as the potential cause of long QT syndrome in five cases. Three cases showed a family history of sudden arrhythmogenic death.Conclusions: Our prospective study identifies 0.14% of cases with a definite long QT, supporting implementation of electrocardiograms in routine pediatric protocols. It is an effective, simple and non-invasive approach that can help prevent sudden death in neonates and their relatives. Genetic analyses help to unravel the cause of arrhythmogenic disease in diagnosing neonates. Further, clinical assessment and genetic analysis of relatives allowed early identification of family members at risk of arrhythmias helping to adopt preventive personalized measures.

Influence of heart rate correction formulas on QTc interval stability

Monitoring of QTc interval is mandated in different clinical conditions. Nevertheless, intra-subject variability of QTc intervals reduces the clinical utility of QTc monitoring strategies. Since this variability is partly related to QT heart rate correction, 10 different heart rate corrections (Bazett, Fridericia, Dmitrienko, Framingham, Schlamowitz, Hodges, Ashman, Rautaharju, Sarma, and Rabkin) were applied to 452,440 ECG measurements made in 539 healthy volunteers (259 females, mean age 33.3 ± 8.4 years). For each correction formula, the short term (5-min time-points) and long-term (day-time hours) variability of rate corrected QT values (QTc) was investigated together with the comparisons of the QTc values with individually corrected QTcI values obtained by subject-specific modelling of the QT/RR relationship and hysteresis. The results showed that (a) both in terms of short-term and long-term QTc variability, Bazett correction led to QTc values that were more variable than the results of other corrections (p < 0.00001 for all), (b) the QTc variability by Fridericia and Framingham corrections were not systematically different from each other but were lower than the results of other corrections (p-value between 0.033 and < 0.00001), and (c) on average, Bazett QTc values departed from QTcI intervals more than the QTc values of other corrections. The study concludes that (a) previous suggestions that Bazett correction should no longer be used in clinical practice are fully justified, (b) replacing Bazett correction with Fridericia and/or Framingham corrections would improve clinical QTc monitoring, (c) heart rate stability is needed for valid QTc assessment, and (d) development of further QTc corrections for day-to-day use is not warranted.