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ABSTRACT: Context: PCOS is one of the most neglected noncommunicable diseases, and early detection would be of great value to primary care physicians. Sympathovagal imbalance detected using heart rate variability (HRV) can be used to detect early autonomic changes if any. Aim: The present study aimed to evaluate QTc and Poincare plot (nonlinear analysis of HRV) in young adolescent PCOS patients. Materials and Methods: It was a cross-sectional study involving 25 PCOS and 25 healthy individuals of age group 12–18 years. HRV was evaluated using the lead II ECG for 10 min from which QTc was calculated manually using the Bazett formula. Student's t -test was used to assess differences between means. A P value < 0.05 was taken for statistical significance. The association between QTc and Poincare plot descriptors was assessed by Pearson's correlation analysis. Results: HRV linear analysis domain represented as the LF/HF ratio was reported to significantly increased among the PCOS group (P = 0.04). Similarly, the nonlinear analysis of HRV by Poincare plot reported a significant decrease in SD1 (P = 0.04) and SD2 (P = 0.02). The heart rate was significantly increased among the PCOS group (P < 0.001). QTc did not show any significant increase among the PCOS group (P = 0.09). QTc was reported to be positively correlated with SD1 (r = 0.37, P < 0.01), SD2 (r-0.33, P = 0.02), LF HF ratio (r = 0.52, P < 0.001), and BMI (r = 0.92, P < 0.001), respectively. Conclusion: The study suggests that HRV nonlinear analysis can be used as a simple noninvasive tool to evaluate cardiovascular autonomic changes. [ABSTRACT FROM AUTHOR]

Background: Methyl alcohol poisoning (MAP) is a common commercial compound that can lead to significant morbidity and mortality when exposed to high levels. This study aims to describe MAP-related electrocardiography (ECG) changes and post-acute late complications. Materials and Methods: The study was conducted through a retrospective data review between 2017 and 2023. Patient data were recorded, including demographic information, medication use, and laboratory results. Twelve-lead ECG recordings were evaluated and the results were recorded. The cases included in the study were grouped according to QTc distance, ECG findings, late-term complications, treatment status, and mortality. Results: The mean age of all cases included in the study (n = 227) was 43.23 ± 11.11 years, 8 (3.5%) cases were female, and the age distribution was between 19 and 68 years (p = 0.792). The age distribution of QTc groups was not significant (p = 0.792). The mean QTc distance was 442.7 ± 60.1 ms in all cases (n = 227) and 514.08 ± 5.45 ms in cases with mortality (n = 49) (p < 0.001). The mean time to application of the patients to the hospital (n = 227) was 19.1 ± 4.61 h, and blood sugar was 130.7 ± 32.09 mg/dL (p < 0.001). In addition, the mean pH of the cases (n = 227) was 7.14 ± 0.2, bicarbonate was 17.17 ± 4.86 mmol/L, the base deficit was −6.21 ± 3.18 mmol/L, the anion gap was 19.36 ± 7.31 mmol/L, and lactate was 4.82 ± 2.45 mmol/L (p < 0.001). Mortality occurred in 49 (21.6%) of the patients, and all of them were in-hospital deaths. In all cases where mortality occurred, pH was below 6.93 ± 0.22 and severe acidosis was directly related to death. MAP, sinus tachycardia in 31 (13.7%) cases, bradycardia in 8 (3.5%), atrial fibrillation in 5 (2.2%), accelerated idioventricular rhythm in 3 (1.3%), and 11 (4.8%), left bundle branch block, and right bundle branch block were detected in 22 (9.7%). All of these ECG findings were newly developed conditions with no previous history. In the 6-month follow-up after discharge, 4 (1.8%) of the cases developed neurological deficit, 15 (6.6%) had acute coronary syndrome and severe heart failure, 23 (10.1%) had permanent blindness, 6 (2.7%) had renal failure, and 6 (2.7%) had pancreatitis. Conclusions: Methyl alcohol poisoning can cause various ECG changes; sinus tachycardia, nonspecific changes, and QTc prolongation are the most common findings. These changes are more pronounced in cases of severe acidosis. Patients should be warned of late signs of MAP. [ABSTRACT FROM AUTHOR]

The studies regarding prevalence, outcomes, and predictors of prolonged corrected QT (QTc) among COVID-19 patients not on QTc-prolonging medication are not available in the literature. In this retrospective cohort study, the QTc of 295 hospital-admitted COVID-19 patients was analyzed and its association with in-hospital mortality was determined. The QTc was prolonged in 14.6% (43/295) of the study population. Prolonged QTc was seen in patients with older age (P = 0.018), coronary artery disease (P = 0.001), congestive heart failure (P = 0.042), elevated N-terminal-pro-B-type natriuretic peptide (NT-ProBNP) (P < 0.0001), and on remdesivir (P = 0.046). No episode of torsades de pointes arrhythmia or any arrhythmic death was observed among patients with prolonged QTc. The mortality was significantly high in patients with prolonged QTc (P = 0.003). The multivariate logistic regression analysis showed coronary artery disease (odds ratio (OR): 4.153, 95% CI 1.37–14.86; P = 0.013), and NT-ProBNP (ng/L) (OR: 1.000, 95% CI 1.000–1.000; P = 0.007) as predictors of prolonged QTc. The prolonged QTc was associated with the worst in-hospital survival (p by log-rank 0.001). A significant independent association was observed between prolonged QTc and in-hospital mortality in multivariate cox-regression analysis (adjusted hazard ratio: 3.861; (95% CI 1.719–6.523), P < 0.0001). QTc was found to be a marker of underlying comorbidities among COVID-19 patients. Prolonged QTc in hospitalized COVID-19 patients was independently associated with in-hospital mortality. [ABSTRACT FROM AUTHOR]

Background Cyclin-dependent kinases (CDK) 4/6 inhibitors have significantly improved outcomes for patients with ER+/HER2− breast cancer. Nevertheless, they differ from each other in terms of chemical, biological, and pharmacological features, as well as toxicity profiles. We aim to determine whether QTc prolongation is caused by CDK4/6i in general or if it is associated with ribociclib only. Methods We systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs) comparing the prevalence of QTc prolongation as an adverse event in HR+ breast cancer patients treated with CDK4/6i vs those without CDK4/6i. We pooled relative risk (RR) and mean difference (MD) with 95% confidence interval (CI) for the binary endpoint of QT prolongation. Results We included 14 RCTs comprising 16 196 patients, of whom 8576 underwent therapy with CDK4/6i. An increased risk of QTc prolongation was associated with the use of CDK4/6i (RR = 2.35, 95% CI = 1.67 to 3.29, P  < .001; I2 = 44%). Subgroup analyses revealed a significant increase in the QTc interval for the ribociclib and palbociclib cohorts. The ribociclib subgroup showed a relative risk of 3.12 (95% CI = 2.09 to 4.65, P  < .001; I2 = 12%), whereas the palbociclib subgroup had a relative risk of 1.51 (95% CI = 1.05 to 2.15, P  = .025; I2 = 0%). Conclusion Palbociclib was associated with QTc prolongation; however, the relative risk for any grade QTc was quantitively twice with ribociclib. Furthermore, grade 3 QTc prolongations were observed exclusively with ribociclib. These results are important for guiding clinical decision-making and provide reassurance regarding the overall safety profile of this drug class. [ABSTRACT FROM AUTHOR]

Context: PCOS is one of the most neglected noncommunicable diseases, and early detection would be of great value to primary care physicians. Sympathovagal imbalance detected using heart rate variability (HRV) can be used to detect early autonomic changes if any. Aim: The present study aimed to evaluate QTc and Poincare plot (nonlinear analysis of HRV) in young adolescent PCOS patients. Materials and Methods: It was a cross-sectional study involving 25 PCOS and 25 healthy individuals of age group 12–18 years. HRV was evaluated using the lead II ECG for 10 min from which QTc was calculated manually using the Bazett formula. Student’s t-test was used to assess differences between means. A P value < 0.05 was taken for statistical significance. The association between QTc and Poincare plot descriptors was assessed by Pearson’s correlation analysis. Results: HRV linear analysis domain represented as the LF/HF ratio was reported to significantly increased among the PCOS group (P = 0.04). Similarly, the nonlinear analysis of HRV by Poincare plot reported a significant decrease in SD1 (P = 0.04) and SD2 (P = 0.02). The heart rate was significantly increased among the PCOS group (P < 0.001). QTc did not show any significant increase among the PCOS group (P = 0.09). QTc was reported to be positively correlated with SD1 (r = 0.37, P < 0.01), SD2 (r-0.33, P = 0.02), LF HF ratio (r = 0.52, P < 0.001), and BMI (r = 0.92, P < 0.001), respectively. Conclusion: The study suggests that HRV nonlinear analysis can be used as a simple noninvasive tool to evaluate cardiovascular autonomic changes.

Understanding the cardiac risks of antipsychotic use is crucial for clinicians managing psychiatric conditions in children and adolescents. However, the effects on the QT interval in pediatric populations have been poorly investigated. We performed a systematic review to provide clinicians an updated source on the effects of antipsychotic medications on QTc and guide drug’s choice. A literature search on the PubMed and Scopus databases was conducted from April 22, 1989, to May 28, 2023, for all studies investigating the effects of antipsychotic medications on the QTc interval in patients aged 0–18 years. A total of 10 articles including 523 patients and 7 different antipsychotic drugs met our search criteria. Among the included articles were three randomized clinical trials, five controlled trials without randomization or prospective comparative cohort trials, and two retrospective cohort studies. Clinical data emerging from these studies were classified according to the Oxford Centre for Evidence-Based Medicine. Risperidone and aripiprazole showed minimal to no significant QTc prolongation, whereas quetiapine, olanzapine, and ziprasidone showed variable effects on QTc. Haloperidol did not demonstrate significant QTc prolongation. In a prospective comparative cohort trial, pimozide exhibited significant QTc prolongation in a cohort with Tourette syndrome. Conclusion: Only 10 studies have carefully addressed the effect of antipsychotic medications on QTc among pediatric patients, underscoring the need for further research. Personalized risk assessment and regular cardiac monitoring should be integrated into clinical management of pediatric and adolescent patients receiving antipsychotics to facilitate early detection of repolarization abnormalities and potential intervention. What is known: • QT interval prolongation is a reported side effect of antipsychotics among adults especially with first-generation antipsychotics and parenteral infusion. • Understanding the effect of antipsychotics on QT is essential for clinical monitoring and avoidance of complications. What is new: • Risperidone and aripiprazole were the most studied antipsychotics in pediatric patients and showed minimal QT prolongation. • The absence of a standardized protocol for assessing the effects on the QT interval makes comparisons between studies challenging and emphasizes the need for further research. [ABSTRACT FROM AUTHOR]

Background: In hospitalized patients, QT/QTc (heart rate corrected) prolongation on the electrocardiogram (ECG) increases the risk of torsade de pointes. Manual measurements are time-consuming and often inaccurate. Some bedside monitors automatically and continuously measure QT/QTc; however, the agreement between computerized versus nurse-measured values has not been evaluated. Objective: The aim of this study was to examine the agreement between computerized QT/QTc and bedside and expert nurses who used electronic calipers. Methods: This was a prospective observational study in 3 intensive care units. Up to 2 QT/QTc measurements (milliseconds) per patient were collected. Bland-Altman test was used to analyze measurement agreement. Results: A total of 54 QT/QTc measurements from 34 patients admitted to the ICU were included. The mean difference (bias) for QT comparisons was as follows: computerized versus expert nurses, −11.04 ± 4.45 milliseconds (95% confidence interval [CI], −2.3 to −19.8; P =.016), and computerized versus bedside nurses, −13.72 ± 6.70 (95% CI, −0.70 to −26.8; P =.044). The mean bias for QTc comparisons was as follows: computerized versus expert nurses, −12.46 ± 5.80 (95% CI, −1.1 to −23.8; P =.035), and computerized versus bedside nurses, −18.49 ± 7.90 (95% CI, −3.0 to −33.9; P =.022). Conclusion: Computerized QT/QTc measurements calculated by bedside monitor software and measurements performed by nurses were in close agreement; statistically significant differences were found, but differences were less than 20 milliseconds (on-half of a small box), indicating no clinical significance. Computerized measurements may be a suitable alternative to nurse-measured QT/QTc. This could reduce inaccuracies and nurse burden while increasing adherence to practice recommendations. Further research comparing computerized QT/QTc from bedside monitoring to standard 12-lead electrocardiogram in a larger sample, including non-ICU patients, is needed. [ABSTRACT FROM AUTHOR]

Objective: To study the clinical effect of heart rate corrected QT (QTc), heart rate corrected Tp-Te (Tp-Tec) interval combined with serum brain natriuretic peptide (BNP) and galectin-3 (Gal-3) in predicting ventricular arrhythmia (VA) after acute myocardial infarction (AMI). Methods: 182 AMI patients who were treated in Jinan People's Hospital from January to July 2023 were select- ed as study subjects. Group based on whether VA occurred during hospitalization, with 71 patients with VA as the observation group and 111 patients without VA as the control group. The levels of QTc, Tp-Tec, serum BNP and Gal-3 were detected and compared between two groups. The influencing factors of VA after AMI were analyzed by multivariate Logistic regression analysis, the predictive efficacy of QTc, Tp-Tec combine with serum BNP and Gal-3 on VA after AMI were analyzed by receiver operating characteristic (ROC) curve. Results: The levels of QTc, Tp-Tec, serum BNP and Gal-3 in observation group were higher than those in control group (P<0.05). Multi- variate Logistic regression analysis showed that elevated QTc, Tp-Tec, BNP and Gal-3 and double/multiple vascular lesions were risk factors for VA after AMI. ROC curve analysis showed that, the combined detection of QTc, Tp-Tec, BNP and Gal-3 had the best predictive efficacy for VA after AMI, with AUC of 0.864, sensitivity of 92.50%, specificity of 79.83% and Youden index of 0.723. Conclusion: The levels of QTc, Tp-Tec, BNP and Gal-3 in VA patients after AMI are increase, and are risk factors for VA after AMI. The combine detection of QTc, Tp-Tec, BNP and Gal-3 has a good predictive value for VA after AMI. [ABSTRACT FROM AUTHOR]

Introduction: Although prior studies indicate that a QTc > 500 ms on a single baseline 12‐lead electrocardiogram (ECG) is associated with significantly increased risk of arrhythmic events in long QT syndrome (LQTS), less is known about the risk of persistent QT prolongation. We sought to determine QTc persistence and its prognostic effect on breakthrough cardiac events (BCEs) among pediatric patients treated for LQTS. Methods: We performed a retrospective analysis of 433 patients with LQTS evaluated, risk‐stratified, and undergoing active guideline‐based LQTS treatment between 1999 and 2019. BCEs were defined as arrhythmogenic syncope/seizure, sudden cardiac arrest (SCA), appropriate VF‐terminating ICD shock, and sudden cardiac death (SCD). Results: During the median follow‐up of 5.5 years (interquartile range [IQR] = 3–9), 32 (7%) patients experienced a total of 129 BCEs. A maximum QTc threshold of 520 ms and median QTc threshold of 490 ms were determined to be strong predictors for BCEs. A landmark analysis controlling for age, sex, genotype, and symptomatic status demonstrated models utilizing both the median QTc and maximum QTc demonstrated the highest discriminatory value (c‐statistic = 0.93–0.95). Patients in the high‐risk group (median QTc > 490 ms and maximum QTc > 520 ms) had a significantly lower BCE free survival (70%–81%) when compared to patients in both medium‐risk (93%–97%) and low‐risk (98%–99%) groups. Conclusions: The risk of BCE among patients treated for LQTS increases not only based upon their maximum QTc, but also their median QTc (persistence of QTc prolongation). Patients with a maximum QTc > 520 ms and median QTc > 490 ms over serial 12‐lead ECGs are at the highest risk of BCE while on guideline‐directed medical therapy. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is a major global burden and a leading cause of premature death among patients with severe mental illness. Over time, research and clinical practice have paid increased attention to the impact of psychiatric medications on cardiac repolarization. In a resource-limited setting, it is common for psychotropic medications to be initiated and maintained in an outpatient setting without baseline or follow up ECG. This study evaluated the determinants and predictors of QT abnormalities among patient taking psychotropic drugs. We conducted a cross-sectional study in a population of 150 psychiatric patients on psychotropics and 75 controls. We studied the effects of various psychotropic drugs on QT dispersion (QTd) and corrected QT interval (QTc) as well as correlation with the types and dosages of psychotropic drugs used. All the subjects had detailed clinical examination and resting electrocardiogram (ECG) at 25 mm/sec done. QTc was determined using Bazett formula and QTd was determined by subtracting shortest from longest QT in 12-lead ECG. The prevalence of prolonged QTc and QTd as well as the mean QTc and QTd were significantly higher in patients than the control group. The mean QTc was significantly higher in patient on typical antipsychotics compared to those on atypical antipsychotics. Age, heart rate and antipsychotic dose in chlorpromazine equivalent were predictors of QTc with the heart rate being the most powerful predictor among them. Psychotropic drugs use is associated with QTc and QTd prolongation with age, heart rate and antipsychotic dose as predictors of QTc. [ABSTRACT FROM AUTHOR]

Abstract Background Anamorelin, a drug to treat cancer cachexia, binds to ghrelin receptors and improves body weight and appetite. In clinical trials in Japan, patients experienced a 10.7% frequency of stimulant conduction system depression as a severe side effect. Although rare, anamorelin sometimes causes fatal arrhythmias. Because patients with cancer cachexia are often underweight, data on the safety of anamorelin in obese patients are lacking. We report a case of QT interval prolongation after anamorelin administration to an obese patient with non-small cell lung cancer. Case presentation A female patient with a body mass index of 30 kg/m2 underwent immunotherapy for lung adenocarcinoma. She presented with severe weight loss, anorexia, and fatigue. She had no history of heart disease. On day 12, after administration of anamorelin 100 mg once daily, the patient developed nausea, diarrhea, and anorexia, which were considered cancer immunotherapy-induced immune-related adverse events, and she was admitted to the hospital. An electrocardiogram (ECG) on admission showed a QTc interval of 502 ms. On admission, her hepatic function was Child–Pugh class B, and anamorelin was discontinued the next day. On day 3 after anamorelin discontinuation, the QTc interval was prolonged by up to 557 ms, then decreased to 490 ms on day 6, and improved to 450 ms on day 16. Re-administration of anamorelin was avoided. Conclusions When administering anamorelin to obese patients, we should be aware of the potential for stimulatory conduction system depression, as in underweight patients. Therefore, we should monitor patients by ECG from the early stages of anamorelin administration. Anamorelin is lipophilic, and its volume of distribution is increased in obese patients. Consequently, obese patients may continue to have QT interval prolongation after discontinuation of anamorelin, requiring long-term side-effect monitoring.

Background: Anamorelin, a drug to treat cancer cachexia, binds to ghrelin receptors and improves body weight and appetite. In clinical trials in Japan, patients experienced a 10.7% frequency of stimulant conduction system depression as a severe side effect. Although rare, anamorelin sometimes causes fatal arrhythmias. Because patients with cancer cachexia are often underweight, data on the safety of anamorelin in obese patients are lacking. We report a case of QT interval prolongation after anamorelin administration to an obese patient with non-small cell lung cancer. Case presentation: A female patient with a body mass index of 30 kg/m2 underwent immunotherapy for lung adenocarcinoma. She presented with severe weight loss, anorexia, and fatigue. She had no history of heart disease. On day 12, after administration of anamorelin 100 mg once daily, the patient developed nausea, diarrhea, and anorexia, which were considered cancer immunotherapy-induced immune-related adverse events, and she was admitted to the hospital. An electrocardiogram (ECG) on admission showed a QTc interval of 502 ms. On admission, her hepatic function was Child–Pugh class B, and anamorelin was discontinued the next day. On day 3 after anamorelin discontinuation, the QTc interval was prolonged by up to 557 ms, then decreased to 490 ms on day 6, and improved to 450 ms on day 16. Re-administration of anamorelin was avoided. Conclusions: When administering anamorelin to obese patients, we should be aware of the potential for stimulatory conduction system depression, as in underweight patients. Therefore, we should monitor patients by ECG from the early stages of anamorelin administration. Anamorelin is lipophilic, and its volume of distribution is increased in obese patients. Consequently, obese patients may continue to have QT interval prolongation after discontinuation of anamorelin, requiring long-term side-effect monitoring. [ABSTRACT FROM AUTHOR]

The case series reviews differential diagnosis of a genetic arrhythmia syndrome when evaluating a patient with prolonged QTc. Making the correct diagnosis requires: detailed patient history, family history, and careful review of the electrocardiogram (ECG). Signs and symptoms and ECG characteristics can often help clinicians make the diagnosis before genetic testing results return. These skills can help clinicians make an accurate and timely diagnosis and prevent life-threatening events. [ABSTRACT FROM AUTHOR]

Objective: Ibogaine is a hallucinogenic drug that may be used to treat opioid use disorder (OUD). The relationships between pharmacokinetics (PKs) of ibogaine and its metabolites and their clinical effects on side effects and opioid withdrawal severity are unknown. We aimed to study these relationships in patients with OUD undergoing detoxification supported by ibogaine. Methods: The study was performed in 14 subjects with OUD. They received a single dose of 10mg/kg ibogaine hydrochloride. Plasma PKs of ibogaine, noribogaine, and noribogaine glucuronide were obtained during 24 h. Cytochrome P450 isoenzyme 2D6 (CYP2D6) genotyping was performed. The PKs were analyzed by means of nonlinear mixed effects modeling and related with corrected QT interval (QTc) prolongation, cerebellar ataxia, and opioid withdrawal severity. Results: The PK of ibogaine were highly variable and significantly correlated to CYP2D6 genotype (p < 0.001). The basic clearance of ibogaine (at a CYP2D6 activity score (AS) of 0) was 0.82 L/h. This increased with 30.7 L/h for every point of AS. The relation between ibogaine plasma concentrations and QTc was best described by a sigmoid E max model. Spearman correlations were significant (p < 0.03) for ibogaine but not noribogaine with QTc (p = 0.109) and cerebellar effects (p = 0.668); neither correlated with the severity of opioid withdrawal symptoms. Conclusions: The clearance of ibogaine is strongly related to CYPD2D6 genotype. Ibogaine cardiac side effects (QTc time) and cerebellar effects are most likely more driven by ibogaine rather than noribogaine. Future studies should aim at exploring lower doses and/or applying individualized dosing based on CYP2D6 genotype. [ABSTRACT FROM AUTHOR]

Icenticaftor (QBW251) is a potentiator of the cystic fibrosis transmembrane receptor. Based on its mechanism of action, icenticaftor is expected to provide benefits in patients with chronic obstructive pulmonary disease by restoring mucociliary clearance, which would eventually lead to a reduction of bacterial colonization and related inflammatory cascade. A placebo‐ and positive‐controlled, 4‐way crossover thorough QT study was conducted in 46 healthy participants with the objective to assess the effect of therapeutic (300 mg twice daily for 6 days) and supratherapeutic (750 mg twice daily for 6 days) oral doses of icenticaftor on electrocardiogram parameters, including concentration‐corrected QT (QTc) analysis. Moxifloxacin (400 mg, oral) was used as a positive control. In the concentration‐QTc analysis performed on pooled data from Day 1 and Day 6 (steady state), the estimated population slope was shallow and slightly negative: –0.0012 ms/ng/mL. The effect on the Fridericia corrected QT (QTcF) interval (∆ΔQTcF) was predicted to be −1.3 milliseconds at the icenticaftor 300‐mg twice‐daily peak concentration (geometric mean was 1094 ng/mL) and −5.5 milliseconds at the 750‐mg twice‐daily peak concentration (geometric mean Cmax was 4529 ng/mL) indicated a mild shortening effect of icenticaftor on QTcF interval length. The results of the by‐time‐point analysis indicated least squares placebo corrected mean ∆∆QTcF across time points ranged from –7.9 to 0.1 milliseconds at 1 and 24 hours after dosing both on Day 6 in the 750‐mg dose group compared with –3.7 to 1.6 milliseconds at 1.5 and 24 hours after dosing on Day 1 in the 300‐mg dose group. Assay sensitivity was demonstrated with moxifloxacin. The large accumulation of exposures, especially the 4.3‐fold increase in peak plasma concentration observed at the icenticaftor 750‐mg twice‐daily dosage compared with Icenticaftor 300 mg twice daily (2.3‐fold) on Day 6 provided a large concentration range (up to 9540 ng/mL) to evaluate the effect of icenticaftor on ΔΔQTcF. Based on the concentration–QTc analysis, an effect on ΔΔQTcF exceeding 10 milliseconds can be excluded within the full observed ranges of plasma concentrations on icenticaftor, up to approximately 9540 ng/mL. Icenticaftor at the studied doses demonstrated a mild shortening in QTcF, which is unlikely to be of clinical relevance in a therapeutic setting. [ABSTRACT FROM AUTHOR]

Dario Kohlbrenner,1,2 Maya Bisang,1 Sayaka S Aeschbacher,1 Emanuel Heusser,1 Silvia Ulrich,1,2 Konrad E Bloch,1,2 Michael Furian1,3 1Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland; 2Faculty of Medicine, University of Zurich, Zurich, Switzerland; 3Swiss University of Traditional Chinese Medicine, Bad Zurzach, SwitzerlandCorrespondence: Michael Furian, Department of Pulmonology, University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland, Email michael.furian@usz.chStudy Objectives: To assess the diagnostic accuracy of a purpose-designed QTc-scoring algorithm versus the established hand-scoring in patients with chronic obstructive pulmonary disease (COPD) undergoing sleep studies.Methods: We collected 62 overnight electrocardiogram (ECG) recordings in 28 COPD patients. QT-intervals corrected for heart rate (QTc, Bazett) were averaged over 1-min periods and quantified, both by the algorithm and by cursor-assisted hand-scoring. Hand-scoring was done blinded to the algorithm-derived results. Bland-Altman statistics and confusion matrixes for three thresholds (460, 480, and 500ms) were calculated.Results: A total of 32944 1-min periods and corresponding mean QTc-intervals were analysed manually and by computer. Mean difference between manual and algorithm-based QTc-intervals was − 1ms, with limits of agreement of − 18 to 16ms. Overall, 2587 (8%), 357 (1%), and 0 QTc-intervals exceeding the threshold 460, 480, and 500ms, respectively, were identified by hand-scoring. Of these, 2516, 357, and 0 were consistently identified by the algorithm. This resulted in a diagnostic classification accuracy of 0.98 (95% CI 0.98/0.98), 1.00 (1.00/1.00), and 1.00 (1.00/1.00) for 460, 480, and 500ms, respectively. Sensitivity was 0.97, 1.00, and NA for 460, 480, and 500ms, respectively. Specificity was 0.98, 1.00, and 1.00 for 460, 480, and 500ms, respectively.Conclusion: Overall, 8% of nocturnal 1-min periods showed clinically relevant QTc prolongations in patients with stable COPD. The automated QTc-algorithm accurately identified clinically relevant QTc-prolongations with a very high sensitivity and specificity. Using this tool, hospital sleep laboratories may identify asymptomatic patients with QTc-prolongations at risk for malignant arrhythmia, allowing them to consult a cardiologist before an eventual cardiac event.Keywords: QTc, long-QT syndrome, COPD, algorithm, validity, ECG

BackgroundThe Tpeak-end(Tp-e) has not been compared in all 12 ECG leads in healthy adults to determine if the Tp-e varies across leads. If there is variation, it remains uncertain, which lead(s) are preferred for recording in order to capture the maximal Tp-e value.ObjectiveThe purpose of the current study was to determine the optimal leads, if any, to capture the maximal Tp-e interval in healthy young adults.MethodsIn 88 healthy adults (ages 21-38 years), including derivation (n = 21), validation (n = 20), and smoker/vaper (n = 47) cohorts, the Tp-e was measured using commercial computer software (LabChart Pro 8 with ECG module, ADInstruments) in all 12 leads at rest and following a provocative maneuver, abrupt standing. Tp-e was compared to determine which lead(s) most frequently captured the maximal Tp-e interval.ResultsIn the rest and abrupt standing positions, the Tp-e was not uniform among the 12 leads; the maximal Tp-e was most frequently captured in the precordial leads. At rest, grouping leads V2-V4 resulted in detection of the maximum Tp-e in 85.7% of participants (CI 70.7, 99.9%) versus all other leads (p

Escitalopram can cause prolongation of the QT interval on the electrocardiogram (ECG). However, only some patients get pathological QTc prolongation in clinic. We investigated the influence of KCNQ1, KCNE1, and KCNH2 gene polymorphisms along with clinical factors on escitalopram-induced QTc prolongation. A total of 713 patients prescribed escitalopram were identified and had at least one ECG recording in this retrospective study. 472 patients with two or more ECG data were divided into QTc prolongation (n = 119) and non-prolongation (n = 353) groups depending on the threshold change in QTc of 30 ms above baseline value (∆QTc ≥ 30 ms). 45 patients in the QTc prolongation group and 90 patients in the QTc non-prolongation group were genotyped for 43 single nucleotide polymorphisms (SNPs) of KCNQ1, KCNE1, and KCNH2 genes. Patients with QTc prolongation (∆QTc ≥ 30 ms) got higher escitalopram dose (10.3 mg) than patients without QTc prolongation (9.4 mg), although no significant relationship was found between QTc interval and escitalopram dose in the linear mixed model. Patients who were older/coronary disease/hypertension or carried with KCNE1 rs1805127 C allele, KCNE1 rs4817668 C allele, KCNH2 rs3807372 AG/GG genotype were significantly at risk for QTc prolongation (∆QTc ≥ 30 ms). Concomitant antipsychotic treatment was associated with a longer QTc interval. A relatively small sample size and lack of the blood concentration of escitalopram restricted the accurate relationship between escitalopram dose and QTc interval. Our study revealed that KCNQ1, KCNE1, and KCNH2 gene polymorphisms along with clinical factors provide a complementary effect in escitalopram-induced QTc prolongation. • Patients with QTc prolongation got higher escitalopram dose. • Greater age, coronary disease, hypertension and concomitant antipsychotics are risk factors for QTc prolongation. • Polymorphism of rs1805127*C and rs4817668*C in KCNE1, and rs3807372*(AG/GG) in KCNH2 are associated with QTc prolongation. [ABSTRACT FROM AUTHOR]

Objective: To analyze the clinical and genetic characteristics of a patient with long QT syndrome type 14 (long QT syndrome‐14, LQT14, OMIM # 616247) caused by a de novo CALM1 mutation. Methods: The clinical data of the patient were collected, next‐generation sequencing technology was used to determine the exome gene sequence of the patient, and the suspected pathogenic locus was verified by Sanger sequencing. Results: A 5‐year and 9‐month‐old girl was admitted to the hospital due to a syncopal episode. During the attack, the main symptoms were loss of consciousness, cyanosis of the face and lips, and weakness of limbs. The child had multiple seizures in the past, all of which occurred after emotional excitement and activity. She was diagnosed with epilepsy for more than 3 years, but the effect of antiepileptic treatment was not satisfactory. The electrocardiogram was normal in the past. A month ago, convulsions occurred again after exercise, and the electrocardiogram showed QTc 496 ms. The treadmill test showed a significant prolongation of QTc after exercise, and the genetic results suggested a new heterozygous variant of CALM1, c.395A>G; p. (Asp132Gly). Consequently, she was diagnosed with LQT14 and treated with propranolol. During a follow‐up of 15 months, there were no seizures or syncope. Conclusions: This patient had multiple episodes of convulsions or syncope after emotional stimulation or activity, with intermittent prolongation of the QTc on routine ECG, marked prolongation of the QTc after exercise, and T‐wave alternans, which differed from the LQT14 phenotype caused by the previous CALM1 mutation. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to evaluate ventricular repolarization before, at the first month, and sixth month after Sacubutril/Valsartan, an angiotensin receptor neprilysin inhibitor (ARNI) treatment in heart failure patients with reduced ejection fraction (HFrEF). Materials and Methods: We included 49 patients with HFrEF who switched to ARNI therapy. The 12-lead electrocardiography (ECG) was evaluated before ARNI therapy and also during the first and sixth months of the therapy. We evaluated demographic, clinical, and laboratory parameters, as well as medications and ECG data, including heart rate. Additionally, we examined QT, QTc, Tp-e, Tp-e calculated (Tp-ec), Tp-ec/QTc, Tpe/QT, and Tp-e/QTc. Results: After receiving ARNI treatment, ventricular repolarization indices were significantly reduced in the first and sixth months compared to before treatment. Specifically, the QTc values decreased from 457.6 ms to 443.8 ms, and the Tp-e/QT ratio decreased from 0.21±0.03 to 0.19±0.03. Additionally, the QTc values decreased from 457.6 ms to 444.9 ms, and the Tp-e/QT ratio decreased from 0.21±0.03 to 0.18±0.03. However, when the first and sixth months under ARNI treatment were compared, no significant difference was found (QTc: 443.8 ms vs. 444.9 ms, Tp-e/QT: 0.19±0.03 vs. 0.18±0.003). Conclusion: ARNI treatment in HFrEF positively affected QTc, Tp-e, and Tp-ec intervals and Tp-e/QT, Tp-e/QTc, and Tp-ec/QTc ratios, which are indicators of ventricular repolarization. Moreover, this effect started in the first month and continued in the sixth month. [ABSTRACT FROM AUTHOR]

To monitor for drug-related cardiac arrhythmias, psychiatrists regularly perform and interpret 12-lead (12L) and, increasingly often, six-lead (6L) electrocardiograms (ECGs). It is not known how training on this complex skill is updated or how well psychiatrists can interpret relevant arrhythmias on either device.

Abstract Background The predictive utility of QTc values, calculated through various correction formulas for the incidence of postoperative major adverse cardiovascular and cerebrovascular events (MACCE) in patients experiencing acute myocardial infarction (AMI), warrants further exploration. This study endeavors to ascertain the predictive accuracy of disparate QTc values for MACCE occurrences in patients with perioperative AMI. Methods A retrospective cohort of three hundred fourteen AMI patients, comprising 81 instances of in-hospital MACCE and 233 controls, was assembled, with comprehensive collection of baseline demographic and clinical data. QTc values were derived employing the correction formulas of Bazett, Fridericia, Hodges, Ashman, Framingham, Schlamowitz, Dmitrienko, Rautaharju, and Sarma. Analytical methods encompassed comparative statistics, Spearman correlation analysis, binary logistic regression models, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). Results QTc values were significantly elevated in the MACCE cohort compared to controls (P

Aim:Gonadotropin-releasing hormone analogs (GnRHa) are standard medical treatments for precocious puberty. Studies on their side effects in adults have shown that these drugs can cause changes in electrocardiography (ECG), along with some cardiovascular effects; however, the number of studies on children is limited. This study investigated the effects of these drugs on ECG parameters in children diagnosed with central precocious puberty (CPP).Materials and Methods:This prospective study included 44 girls who were initiated GnRHa treatment and diagnosed with CPP. ECG was performed before treatment and repeated after 6 months of treatment.Results:The mean age of the children was 9.13±1.55 years. Leuprolide acetate (3.75 mg IM) was administered to all of the patients following the standard protocol. A comparison of the pre-treatment and 6-month ECG parameters revealed a prolonged QT interval after treatment, with a statistically significant difference (p0.05).Conclusion:Despite a significant increase in QT interval on ECG with GnRHa compared to pre-treatment ECGs, this increase was attributed to a variability in heart rate. Even if regular ECG monitoring is considered after initiation of GnRHa treatment, they are believed to be safe drugs in children.

BackgroundECG abnormalities have been linked to adverse changes in right ventricular (RV) morphology and poor clinical outcomes in repaired Tetralogy of Fallot (rTOF). Our aim was to describe how ECG changes progress in early and intermediate follow-up and whether types of surgical strategy at the time of primary repair affected these changes.MethodsWe studied patients with rTOF born 2000–2018 operated at our institution. Seven time points in relation to primary repair, follow-up, and pulmonary valve replacement (PVR) were identified. Patients correct with valve sparing repair (VSR), trans-annular patch (TAP) including with a monocusp valve (TAP + M) and with at least 3 ECGs were included. PQ interval, QRS duration, dispersion, and fragmentation, QTc duration and dispersion, JTc as well as presence of a right bundle branch block (RBBB) were analyzed. Medical records were reviewed for demographic and surgical data.ResultsTwo hundred nineteen patients with 882 ECGs were analyzed with a median follow-up time of 12.3 years (8.4, 17) with 41 (19%) needing PVR during the study period. QRS duration increased at time of primary repair to discharge from 66 msec (IQR 12) to 129 msec (IQR 27) (p

To monitor for drug-related cardiac arrhythmias, psychiatrists regularly perform and interpret 12-lead (12L) and, increasingly often, six-lead (6L) electrocardiograms (ECGs). It is not known how training on this complex skill is updated or how well psychiatrists can interpret relevant arrhythmias on either device. We conducted an online survey and ECG interpretation test of cardiac rhythms relevant to psychiatrists. A total of 183 prescribers took part; 75% did not regularly update their ECG interpretation skills, and only 22% felt confident in interpreting ECGs. Most participants were able to recognise normal ECGs. For both 6L and 12L ECGs, the majority of participants were able to recognise abnormal ECGs, but fewer than 50% were able to correctly identify relevant arrhythmias (complete heart block and long QTc). A small number prescribed in the presence of potentially fatal arrhythmias. These findings suggest a need for mandatory ECG interpretation training to improve safe prescribing practice. [ABSTRACT FROM AUTHOR]

Objective To explore the effect of ivabradine on QT interval and sinus rhythm in patients with chronic heart failure (HF). Methods A total of 179 patients with chronic HF were selected as the research subjects. They underwent 12-lead synchronous ambulatory electrocardiography (AECG) examination, and reexamination of AECG 30-45 days after oral administration of ivabradine. The changes of QT interval and heart rate before and after medication were compared. Results A total of 143 patients complete clinical follow-up and are enrolled in this study. After oral administration of ivabradine, the maximum QT interval [(467. 9 ± 62. 6)ms vs. (473. 6±63.4) ms], the maximum QTc [(489. 3±56. 0) ms vs. (496. 6±55. 4) ms], the average QT interval [(390. 5±41.1) ms vs. (398. 6±43.7) ms], the average QTc [(417. 2±31. 4) ms vs. (414. 4±36. 9) ms], and the minimum QTc [(377. 5± 36. 0) ms vs. (361.3±37. 0) ms] of all the 143 patients are significantly different from those before medication (P<0. 01). The minimum QT interval [(348. 3 ± 42. 8) ms vs. (349. 6±38. 9) ms] does not vary significantly before and after medication (P > 0. 05). The differences of the minimum heart rate [(50. 3±8. 6) times per minute vs. (47. 7±7. 8) times per minute], the average heart rate [(69. 9±11. 7) times per minute vs. (64. 9±10.6) times per minute], and the maximum heart rate [(116. 6±23.1) times per minute vs. (109. 0±20.1) times per minute] are all statistically significant before and after medication (P<0. 01). During the follow-up period, there is no incidence of ventricular arrhythmia or sudden death. Conclusion Ivabradine could significantly shorten the maximum QT interval / QTc and the average QT interval, and slow down heart rate. Its clinical application is safe and effective. [ABSTRACT FROM AUTHOR]

Background: The predictive utility of QTc values, calculated through various correction formulas for the incidence of postoperative major adverse cardiovascular and cerebrovascular events (MACCE) in patients experiencing acute myocardial infarction (AMI), warrants further exploration. This study endeavors to ascertain the predictive accuracy of disparate QTc values for MACCE occurrences in patients with perioperative AMI. Methods: A retrospective cohort of three hundred fourteen AMI patients, comprising 81 instances of in-hospital MACCE and 233 controls, was assembled, with comprehensive collection of baseline demographic and clinical data. QTc values were derived employing the correction formulas of Bazett, Fridericia, Hodges, Ashman, Framingham, Schlamowitz, Dmitrienko, Rautaharju, and Sarma. Analytical methods encompassed comparative statistics, Spearman correlation analysis, binary logistic regression models, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). Results: QTc values were significantly elevated in the MACCE cohort compared to controls (P < 0.05). Spearman's correlation analysis between heart rate and QTc revealed a modest positive correlation for the Sarma formula (QTcBaz) (ρ = 0.46, P < 0.001). Within the multifactorial binary logistic regression, each QTc variant emerged as an independent risk factor for MACCE, with the Sarma formula-derived QTc (QTcSar) presenting the highest hazard ratio (OR = 1.025). ROC curve analysis identified QTcSar with a threshold of 446 ms as yielding the superior predictive capacity (AUC = 0.734), demonstrating a sensitivity of 60.5% and a specificity of 82.8%. DCA indicated positive net benefits for QTcSar at high-risk thresholds ranging from 0 to 0.66 and 0.71–0.96, with QTcBaz, prevalent in clinical settings, showing positive net benefits at thresholds extending to 0-0.99. Conclusion: For perioperative AMI patients, QTcSar proves more advantageous in monitoring QTc intervals compared to alternative QT correction formulas, offering enhanced predictive prowess for subsequent MACCE incidents. [ABSTRACT FROM AUTHOR]

Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy with an estimated prevalence of 1 in 2500. A prolonged resting QT interval corrected for heart rate (QTc interval) remains a key diagnostic component; however, the QTc value may be normal in up to 40% of patients with genotype-positive LQTS and borderline in a further 30%. Provocation of QTc prolongation and T-wave changes may be pivotal to unmasking the diagnosis and useful in predicting genotype. LQTS provocation testing involves assessment of repolarization during and after exercise, in response to changes in heart rate or autonomic tone, with patients with LQTS exhibiting a maladaptive repolarization response. We review the utility and strengths and limitations of 4 forms of provocation testing—stand-up test, exercise stress test, epinephrine challenge, and mental stress test—in diagnosing LQTS and provide some practical guidance for performing provocation testing. Ultimately, exercise testing, when feasible, is the most useful form of provocation testing when considering diagnostic sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Objective To investigate the correction effect of different QT interval correction formulas applied in various ranges of heart rate. Methods A total of 699 778 ECGs with heart rate ranged from 30 to 200 times/ min were selected from the ECG-ViEW database ( a public information platform of ECGs). These ECGs were divided into four groups including 30-60, 60-100, 100-150 and 150-200 times/ min groups according to the heart rate. The QT interval was corrected by Bazett, Fridericia, Framingham and Hodges formulas respectively. The linear relationship between QTc and heart rate or measured QT interval value was analyzed within different ranges of heart rate and by using different formulas. Results The uncorrected QT interval is prolonged as the heart rate slows down. The Bazett formula shows a poor performance in correcting QT interval, especially in the population with too slow heart rate. The Hodges formula shows a relatively good correction effect among the population with low heart rate but a poor correction effect in those with fast heart rate. The Fridericia and Framingham formulas have relatively good correction effects in the population with normal and fast heart rate. Conclusion The Bazett formula commonly used in clinical practice has some defects in QT interval correction. The Hodges formula shows greater practical value for the patients with low heart rate. The Fridericia and Framingham formulas are more suitable for correcting the ECGs with normal or fast heart rate. [ABSTRACT FROM AUTHOR]

Objective To explore the effect of different correction methods of QT interval in patients with atrial fibrillation (AF) separately at AF and sinus rhythms. Methods The ECGs of AF patients both with AF and sinus rhythms were selected from the public information platform ECG-ViEW database. The correction effect of Bazett, Fridericia, Framingham and Hodges formulas is compared and analyzed for the same patient separately at AF and sinus rhythms. The linear relationship between QTc corrected by different formulas and heart rate or the measured value of QT interval was analyzed. Results There is a statistically significant difference in the QT interval among AF patients during AF and sinus rhythms [(374. 57±67. 73) ms vs. (396. 71±55. 68) ms, P<0. 01]. The QTc corrected by Hodges formula does not vary significantly between the two rhythms. The regression line slope of QTc to the heart rate is very small, and the QTc corrected by Hodges formula shows a good linear relationship with the measured value of QT interval. The QTc corrected by commonly used Bazett formula in clinical practice shows a positive linear relationship with the measured value of QT interval. Conclusion Commonly used Bazett, Fridericia and Framingham formulas lead to poor performances in correcting QT interval of ECGs during AF rhythm. The effect of Hodges formula on correcting QT interval is close separately at AF and sinus rhythms, which could greatly reduce the influence of heart rate on QT interval. Hodges formula is universal in the population, and makes a good clinical indicator for monitoring the prolongation of QT interval in AF patients. [ABSTRACT FROM AUTHOR]

Background: Hydroxychloroquine (HCQ) has been historically used for treatment of autoimmune diseases and more recently, it is used for treatment of COVID-19 patients. Using HCQ in COVID-19 patients resulted in corrected QT(QTc) prolongation which has potential to deteriorate into Torsades de Pointes and sudden cardiac death. As it is used chronically by rheumatologic patients so this study was designed to establish effect of HCQ on QTc in rheumatic patients. Methods: A cross sectional comparative study conducted in Rheumatology Department Shaikh Zayed hospital, Lahore. Non-probability consecutive sampling technique was used. Duration of study was 169 days. 45 patients used HCQ for three months and 45 patients did not use HCQ. ECG was done at induction in the study and after three months. Serum calcium, potassium and magnesium were also checked at onset. QTc was calculated by Bazett's formula. Results: QTc did not raise in 21(46%) patients, in both groups. QTc raised between 1-50msec in 20(44.4%) and 23(51.1%) patients in HCQ exposed and unexposed patients, respectively. QTc rise more than 50msec in 4(8.88%) and 1(2.2%) patient in HCQ exposed and unexposed patients, respectively (p-value=0.344). The QTc change is associated with heart rate showing 75.0% chances of increased QTc among those with increased heart rate. Conclusion: HCQ did not increase QTc interval in 46% study. 8.88% of HCQ exposed population and 2.22% of HCQ unexposed population had significant change in QTc. However, no adverse cardiac events were observed in study duration. [ABSTRACT FROM AUTHOR]

Abstract Background At present, there is not enough evidence to prove the relationship between blood lipid and electrocardiogram (ECG) abnormalities in common mental disorders (CMD). This study aimed to explore the relationship between them, to detect and prevent arrhythmia or sudden death. Methods We collected 272 CMD patients (maintained a fixed drug dose pattern for 1 year or more), including 95 schizophrenias (SC), 90 bipolar disorders (BD) and 87 major depressive disorders (MDD), and 78 healthy controls (HC) from the Third People’s Hospital of Foshan, China. We analyzed and compared their blood lipid and ECG indicators, to clarify the relationship between them. Results 350 participants were included. There were no significant differences in age, gender, total cholesterol (TC), low density lipoprotein (LDL) and QTc (p > 0.05) among subjects. And there were significant differences in body mass index (BMI), triglyceride (TG), high density lipoprotein (HDL), heart rate, PR interval and QRS width (p

Background: Sickle cell disease, a common genetic disorder in African Americans, manifests an increased risk of sudden death, the basis of which is incompletely understood. Prolongation of heart rate–corrected QT (QTc) interval on the electrocardiogram, a standard clinical measure of cardiac repolarization, may contribute to sudden death by predisposing to torsades de pointes ventricular tachycardia. Methods: We established a cohort study of 293 adult and 121 pediatric sickle cell disease patients drawn from the same geographic region as the Jackson Heart Study (JHS) cohort, in which significant correlates of QT duration have been characterized and quantitatively modeled. Herein, we establish clinical and laboratory correlates of QTc duration in our cohort using stepwise multivariate linear regression analysis. We then compared our adult sickle cell disease data to effect-size predictions from the published JHS statistical model of QT interval duration. Results: In adult sickle cell disease, gender, diuretic use, QRS duration, serum ALT levels, anion gap, and diastolic blood pressure show positive correlation; hemoglobin levels show inverse correlation; in pediatric sickle cell disease, age, hemoglobin levels, and serum bicarbonate and creatinine levels show inverse correlation. The mean QTc in our adult sickle cell disease cohort is 7.8 milliseconds longer than in the JHS cohort, even though the JHS statistical model predicts that the mean QTc in our cohort should be >11 milliseconds shorter than in the much older JHS cohort, a differential of >18 milliseconds. Conclusion: Sickle cell disease patients have substantial QTc prolongation relative to their age, driven by factors, some overlapping, in adult and pediatric sickle cell disease, and distinct from those that have been defined in the general African American community.

Careful observation of the QT interval is important to monitor patients with long QT syndrome and during treatment with potentially QT-prolonging medication. It is also crucial in the development of novel drugs, in particular in case of a potential side effect of QT prolongation and in patients with increased risk of QT prolongation. The 12-lead electrocardiogram (ECG) is the gold standard to evaluate cardiac conduction and repolarization times. Smartwatches and smart devices offer possibilities for ambulatory ECG recording and therefore measuring and monitoring the QT interval. We performed a systematic review of studies on smartwatches and smart devices for QTc analysis. We reviewed PubMed for smartwatches and smart devices that can measure and monitor the QT interval. A total of 31 studies were included. The most frequent devices were (1) KardiaMobile 6L, a Food and Drug Administration-approved device for QTc analyses that provides a 6-lead ECG, (2) an Apple Watch, a smartwatch with an integrated ECG tool that allows recording of a single-lead ECG, and (3) the Withings Move ECG ScanWatch, an analog watch with a built-in single-lead ECG. The KardiaMobile 6L device and the Apple Watch provide accurate measurements of the QT interval, although the Apple Watch is studied in standard and non-standard positions, and the accuracy of QT measurements increased when the smartwatch was moved to alternative positions. Most studies were performed on patients, and limited results were available from healthy volunteers.

Aim: Gonadotropin-releasing hormone analogs (GnRHa) are standard medical treatments for precocious puberty. Studies on their side effects in adults have shown that these drugs can cause changes in electrocardiography (ECG), along with some cardiovascular effects; however, the number of studies on children is limited. This study investigated the effects of these drugs on ECG parameters in children diagnosed with central precocious puberty (CPP). Materials and Methods: This prospective study included 44 girls who were initiated GnRHa treatment and diagnosed with CPP. ECG was performed before treatment and repeated after 6 months of treatment. Results: The mean age of the children was 9.13±1.55 years. Leuprolide acetate (3.75 mg IM) was administered to all of the patients following the standard protocol. A comparison of the pre-treatment and 6-month ECG parameters revealed a prolonged QT interval after treatment, with a statistically significant difference (p<0.001). There were no significant differences in the pre- and post-treatment values of PR, QRS, QT interval, QTc interval, QT dispersion, or QTc dispersion (p>0.05). Conclusion: Despite a significant increase in QT interval on ECG with GnRHa compared to pre-treatment ECGs, this increase was attributed to a variability in heart rate. Even if regular ECG monitoring is considered after initiation of GnRHa treatment, they are believed to be safe drugs in children. [ABSTRACT FROM AUTHOR]

Background Prolongation of the QT interval is associated with lethal arrhythmias. Early identification of QT/QTc prolongation followed by appropriate clinical interventions can avert this potentially lethal arrhythmia. Aim of the study To assess the association between QTc-interval prolongation and increased risk of cardiac arrhythmia in critically ill patients. Research design A descriptive correlational research design was utilized. Setting The study was conducted in the Critical Care Department, Al-Manial University Hospital, Cairo University. Patients and methods A purposive sample consisted of 270 adult patients. Tools of data collection An assessment sheet consists of two parts: part I: patients’ demographic and medical data, and part II: QT-interval monitoring sheet. Results The mean age of the study sample was 60.16±16.05, and 53.3% were males. Also, there was a statistically significant difference in patients’ QTc mean through five observations (f=19.086; P≤0.001). Moreover, there was no significant statistical difference in patients’ QT average means through five observations by their laboratory investigations and their diagnosis (P>0.05, P=0.133), respectively. Conclusion The highest prolongation of QTc was in torsade de pointes, and the lowest QTc prolongation was in atrial fibrillation. Recommendation Nursing assessment of critically ill patients in association with QTc calculation for early detection of lethal cardiac arrhythmia. [ABSTRACT FROM AUTHOR]

Aims Sudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined manually, but vendor-provided automatic results from ECG recorders are convenient. Agreement between manual and automatic assessments is unclear for populations with aberrant QTc. We aimed to systematically assess pairwise agreement of automatic and manual QT-intervals and QTc. Methods and results A multi-centre cohort enriching aberrant QTc comprised ECGs of healthy controls and long-QT syndrome (LQTS) patients. Manual QT-intervals and QTc were determined by the tangent and threshold methods and compared to automatically generated, vendor-provided values. We assessed agreement globally by intra-class correlation coefficients and pairwise by Bland–Altman analyses and 95% limits of agreement (LoA). Further, manual results were compared to a novel automatic QT-interval algorithm. ECGs of 1263 participants (720 LQTS patients; 543 controls) were available [median age 34 (inter-quartile range 35) years, 55% women]. Comparing cohort means, automatic and manual QT-intervals and QTc were similar. However, pairwise Bland–Altman-based agreement was highly discrepant. For QT-interval, LoAs spanned 95 (tangent) and 92 ms (threshold), respectively. For QTc, the spread was 108 and 105 ms, respectively. LQTS patients exhibited more pronounced differences. For automatic QTc results from 440–540 ms (tangent) and 430–530 ms (threshold), misassessment risk was highest. Novel automatic QT-interval algorithms may narrow this range. Conclusion Pairwise vendor-provided automatic and manual QT-interval and QTc results can be highly discrepant. Novel automatic algorithms may improve agreement. Within the above ranges, automatic QT-interval and QTc results require manual confirmation, particularly if T-wave morphology is challenging. [ABSTRACT FROM AUTHOR]

Background: Burning mouth syndrome (BMS) is an intractable chronic pain disorder of unknown cause characterized by burning sensation without any organic abnormality in the oral mucosa. In a chronic pain disorder such as BMS, the ability to control pain catastrophizing that accompany the pain determines the outcome of treatment. Pain catastrophizing is associated with the dopamine nervous system and can be quantitatively assessed with the Pain Catastrophizing Scale (PCS). Treatment options include antidepressants, benzodiazepines, antipsychotics, anticonvulsants, analgesics, hormone replacement therapy, and psychotherapy, with antidepressants being the most commonly used and effective. Methods: We analyzed whether amitriptyline and aripiprazole, typical drug therapies for BMS patients, improve PCS using a 2-year case series from our department. We also examined whether changes in QTc and serum prolactin levels were associated with improvement in PCS as an indicator of the efficacy of these monoamine modulators. Results: Both amitriptyline and aripiprazole statistically significantly improved PCS. Amitriptyline increased heart rate and mildly shortened QTc, while aripiprazole did not alter heart rate or QTc. Both amitriptyline and aripiprazole caused very mild increases in prolactin levels. Only prolonged QTc in the aripiprazole group correlated with improved PCS. Discussion and Conclusions: Monoamine-targeted pharmacotherapy for BMS is effective against pain catastrophizing in patients with BMS. Since the dopaminergic nervous system is primarily involved in pain catastrophizing, a mild increase in prolactin levels was therefore found to be associated with efficacy. However, changes in prolactin levels were not predictive of individual treatment response. The anticholinergic effects of amitriptyline on QTc and prolactin may have prevented these markers from predicting treatment response at the individual level. Only prolonged QTc in the aripiprazole group was correlated with efficacy. Aripiprazole has no anticholinergic effects and dopamine stability was observed at QTc, but its agonist effect on prolactin on pituitary cells may not have been a marker of its effect on pain catastrophizing. [ABSTRACT FROM AUTHOR]

Methadone is a chiral synthetic opioid primarily used to treat heroin and prescription-opioid addiction: the (R)-enantiomer (Levomethadone) activates the µ-opioid receptor more potently than the (S)-enantiomer, which is a more potent blocker of the hERG potassium channels, resulting in QTc prolongation. The purpose of this retrospective study was to assess the effect of methadone on the QTc interval and to investigate the benefits of Levomethadone. The electrocardiograms of 165 patients taking methadone at various dosages and for different periods of time were examined: the QTc value was manually measured and then adjusted using Bazett's formula. Data analysis revealed a linear association between the dosage of methadone and QTc length; no correlation was found between the QTc value and gender, age, or duration of therapy. In total, 14% of the sample (23 patients) showed a prolongation of the QTc interval (>470 ms in males and >480 ms in females); 10 of the 23 patients with QTc elongation underwent a change of therapy from Methadone to Levomethadone—in 90% of these patients, a normalization in the QTc length was established. This study confirmed the role of methadone, specifically its dosage, in QTc prolongation and the efficiency of Levomethadone as an adequate therapeutic substitute in these circumstances. This study validates the importance of careful electrocardiographic monitoring in methadone-treated patients. [ABSTRACT FROM AUTHOR]

Bupropion toxicity can cause cardiogenic shock, ventricular dysrhythmias, and death. Clinical and electrocardiographic factors associated with adverse cardiovascular events in bupropion toxicity have not been well-studied. This study aimed to identify factors associated with adverse cardiovascular events in adult patients with isolated bupropion exposures. This retrospective cohort study queried the National Poison Data System from 2019 through 2020. We included patients 20 years or older with acute or acute-on-chronic single-agent bupropion exposures evaluated in a healthcare facility. Exclusion criteria were confirmed non-exposure, withdrawal as a reason for exposure, lack of follow-up, documentation that exposure was probably not responsible for the effects, and missing data. The primary outcome was adverse cardiovascular events, defined as the presence of any of the following: vasopressor use, ventricular dysrhythmia, myocardial injury, or cardiac arrest. Independent variables were age, the intentionality of exposure, seizures, tachycardia, QRS widening, and QTc prolongation. Multivariable logistic regression was performed to test for independent associations between independent variables and adverse cardiovascular events. Of 4,640 patients included in the final analysis (56.7% female, 56.5% suspected suicidal intent), 68 (1.47%) experienced an adverse cardiovascular event. Age (odds ratio 1.03; 95% confidence intervals 1.02–1.05), single seizure (odds ratio 9.18; 95% confidence intervals 4.24–19.9) and complicated seizures (odds ratio 38.9; 95% confidence intervals 19.3–78.1), QRS widening (odds ratio 3.01; 95% confidence intervals 1.62–5.59), and QTc prolongation (odds ratio 1.76; 95% confidence intervals 1.00–3.10) were independently associated with adverse cardiovascular events. No patients with unintentional exposure experienced adverse cardiovascular events, prohibiting intentionality from inclusion in the regression model. In the post hoc subgroup analysis of intentional exposures, age, single and complicated seizures, and QRS widening remained independently associated with adverse cardiovascular events. Increasing age, seizures, QRS widening, and QTc prolongation were associated with adverse cardiovascular events in bupropion exposures. Adverse cardiovascular events did not occur in unintentional exposures. Further research is needed to develop screening tools and treatments for bupropion cardiotoxicity. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to access the incidence of prolonged QTc interval and changes, if any, among Indian healthcare workers (HCWs) taking hydroxychloroquine (HCQ) prophylaxis while managing coronavirus disease 2019 (COVID-19) cases. Methods: At the beginning of the COVID-19 pandemic, as per the Indian Council of Medical Research (ICMR) policy, HCWs were advised to take HCQ as prophylaxis after getting an electrocardiogram (ECG) while being posted to look after COVID-19 patients. A follow-up ECG was repeated for those who took HCQ. The normal upper limit for QTc interval of 460 milliseconds (ms) for females and 450 ms for males was considered. Results: A baseline ECG was analyzed for 250 HCWs with a median age of 35 (30–43) years. The median QTc was 410 (395–421) ms with the prevalence of prolonged QTc of 1.8% in females and 0% in males. A follow-up ECG after HCQ intake for 43 HCWs was further analyzed. They had a median age of 35 (31–39) years and took an average dose of HCQ of 2372 ± 839 mg. Pre- and post-HCQ chemoprophylaxis QTc interval (ms) was as follows: 408 (386–419) and 405 (387–417), with P = 0.434, respectively. Conclusion: Among Indian HCWs, the prevalence of prolonged QTc is 1.8% and 0% in females and males, respectively. HCQ intake as chemoprophylaxis for COVID-19 did not affect their QTc interval.

Imatinib has been reported to induce heart failure and/or QTc prolongation. To better understand their underlying mechanisms, we assessed its effects on cardiohemodynamic, electrocardiographic and echocardiographic variables along with biomarkers of myocardial damage. Imatinib mesylate in doses of 1 and 10 mg/kg was intravenously administered to the halothane-anesthetized beagle dogs (n = 4). Effects of imatinib on each phase of isovolumetric contraction, ejection, isovolumetric relaxation and filling were studied, whereas its electrophysiological effects on early and late repolarization were analyzed by measuring J-Tpeak and Tpeak-Tend, respectively. The low and high doses of imatinib provided peak plasma concentrations of 3.23 and 17.39 μg/mL, reflecting clinically-relevant and supratherapeutic concentrations, respectively. Neither lethal ventricular tachyarrhythmia nor cardiohemodynamic collapse was observed. Imatinib decreased amplitude of peak −dP/dt, indicating suppression of isovolumetric relaxation, whereas no significant change was detected in the other phases. Imatinib prolonged QTc and J-Tpeakc without altering Tpeak-Tend, indicating increase of net inward current, which leads to intracellular Ca2+ overload. Thus, imatinib suppressed ventricular active relaxation and early repolarization, which may suggest the association of mitochondrial dysfunction-associated inhibition of ATP production. Since those findings were also reported for dasatinib, sunitinib and lapatinib, they could be common cardiac phenotype of tyrosine kinase inhibitors in vivo.

Background: At present, there is not enough evidence to prove the relationship between blood lipid and electrocardiogram (ECG) abnormalities in common mental disorders (CMD). This study aimed to explore the relationship between them, to detect and prevent arrhythmia or sudden death. Methods: We collected 272 CMD patients (maintained a fixed drug dose pattern for 1 year or more), including 95 schizophrenias (SC), 90 bipolar disorders (BD) and 87 major depressive disorders (MDD), and 78 healthy controls (HC) from the Third People's Hospital of Foshan, China. We analyzed and compared their blood lipid and ECG indicators, to clarify the relationship between them. Results: 350 participants were included. There were no significant differences in age, gender, total cholesterol (TC), low density lipoprotein (LDL) and QTc (p > 0.05) among subjects. And there were significant differences in body mass index (BMI), triglyceride (TG), high density lipoprotein (HDL), heart rate, PR interval and QRS width (p < 0.05). Person correlation analysis showed that QRS width was positively correlated with BMI and TG. And negatively correlated with HDL. Meanwhile, QTc was positively correlated with BMI. Multiple linear regional analysis further proved that TG (B = 3.849, p = 0.007) and LDL (B = 11.764, p = 0.018) were the risk factors, and HDL (B = -9.935, p = 0.025) was the protective factor for QRS width increase. Conclusion: Long term medication of CMD patients should strengthen weight management, and conduct regular blood lipid and ECG examinations to achieve early detection and intervention in order to promote their health. [ABSTRACT FROM AUTHOR]

The study goal was to investigate electrocardiographic findings, including corrected QT interval (QTc), in patients aged 8 to 23 with eating disorders (EDs) at presentation, compared with an age-and sex-matched control population. We retrospectively reviewed 200 ED patients, and 200 controls. Blinded electrocardiograms (ECGs) were interpreted by an expert reader, and QT intervals corrected using the Bazett formula. Eating disorder patients were 89.5% female, with mean age 16.4 years and median percent median body mass index (BMI)-for-age (%mBMI)a of 91.1%. In ED patients, QTc was significantly shorter than controls (399.6 vs 415.0msec, P <.001). After adjusting for height, %mBMI, sex, magnesium level, and bradycardia, mean QTc duration in patients with anorexia nervosa-restricting subtype (AN-R) was significantly shorter than other ED patients (P =.010). Higher %mBMI was associated with shorter QTc duration (P =.041) after adjusting for height, magnesium, bradycardia, and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis. Within the ED group, no significant association was identified between QTc and medications, electrolytes, or inpatient status. [ABSTRACT FROM AUTHOR]

Introduction: One of the most popular tests of the heart is the electrocardiogram (ECG). The physical basis of this study has been known for over 200 years. However, the way an ECG is performed and the interpretation of the obtained results have undergone considerable evolution over time. Aim: To analyze the ECG recordings regarding the QTc interval in patients taking calcium channel blockers. Material and methods: The publicly available PhysioNet signals database was used to analyze the effect of selected drugs on the heart rhythm and QTc interval. To automate the QTc assessment, the database was processed in MATLAB. First, QTc was assessed using four formulas; then the results were compared in terms of methodology and medications taken. Results: In the group of patients taking dihydropyridine blockers, the QTc interval assessed by the Bazett formula (mean: 478.87 ms; SD: 73.10) is longer than in patients taking non-dihydropyridine blockers (mean: 446.54 ms, SD: 88.07, p = 0.2123) and in patients not taking calcium channel blockers (mean: 436.33 ms, SD: 49.94, p = 0.0319). The same significant differences were obtained regardless of the QTc assessment method used. However, the QTc result obtained with the Bazett formula is significantly lower than in the case of using the other three formulas used for the presented analysis. Conclusions: Automatic ECG analysis is possible; however, it should be used carefully, considering the possibility of obtaining incorrect results. Taking calcium channel blockers may affect the QTc interval. QTc results significantly depend on the formula based on which we evaluate this parameter. [ABSTRACT FROM AUTHOR]

BackgroundSystemic immune inflammatory index (SII) and systemic inflammatory response index (SIRI) are combinations of non-specific inflammatory and adaptive immune response impairments associated with cardiovascular disease. Yet little analysis has been done on SII, SIRI and acute myocardial infarction (AMI) prognosis. The purpose of this study was to investigate the correlation of SII and SIRI with clinical risk factors such as GRACE, Gensini, and QTc after acute myocardial infarction.MethodsThis study enrolled 310 patients with AMI from February 1, 2018, to December 31, 2022, at our institution. Routine blood items calculated SII and SIRI. Two groups were divided according to whether MACE occurred: the MACE group (81 cases) and the NMACE group (229 cases); each group was divided into three groups according to the SII and SIRI tertiles. The relationship between SII, SIRI and MACE was analyzed using multifactorial logistic regression analysis after adjusting for confounders; ROC curves were plotted to examine the predictive value of SII and SIRI for MACE. The correlation between SII and SIRI and potential risk factors such as Gensini, QTc and GRACE was further analyzed.ResultsThe study enrolled 310 patients, comprising 248 men (80%, mean age 60.73 ± 13.695 years) and 62 women (20%, mean age 69.79 ± 11.555 years). In the regression model completely adjusted for confounders, the risk of MACE was higher in AMI patients with SII > 11.00 [OR = 1.061,95% CI (1.018,1.105)] than in SII 3.68 [OR = 1.251, 95% CI (1.123, 1.394)] than in AMI patients with SIRI

Background An elegant bedside provocation test has been shown to aid the diagnosis of long‐QT syndrome (LQTS) in a retrospective cohort by evaluation of QT intervals and T‐wave morphology changes resulting from the brief tachycardia provoked by standing. We aimed to prospectively determine the potential diagnostic value of the standing test for LQTS. Methods and Results In adults suspected for LQTS who had a standing test, the QT interval was assessed manually and automated. In addition, T‐wave morphology changes were determined. A total of 167 controls and 131 genetically confirmed patients with LQTS were included. A prolonged heart rate–corrected QT interval (QTc) (men ≥430 ms, women ≥450 ms) at baseline before standing yielded a sensitivity of 61% (95% CI, 47–74) in men and 54% (95% CI, 42–66) in women, with a specificity of 90% (95% CI, 80–96) and 89% (95% CI, 81–95), respectively. In both men and women, QTc≥460 ms after standing increased sensitivity (89% [95% CI, 83–94]) but decreased specificity (49% [95% CI, 41–57]). Sensitivity further increased (P

BackgroundWith HIV-infected patients living longer, there is an increased burden of comorbidities related to aging, HIV itself, and polypharmacy. Cardiac morbidity is of particular importance.MethodsThis 2-group comparison study (156 HIV-positive and 105 HIV-negative patients) investigated the prevalence of abnormalities in and factors associated with an electrocardiogram (ECG) measure, corrected QT interval (QTc), where prolongation can lead to arrhythmia and sudden death. Medications prescribed (antiretroviral therapy, psychiatric medications, methadone, and antibiotics) at the time of ECG were noted. Patient characteristics, medications, QTc, and ECG characteristics were compared between the 2 groups.ResultsProlongation (29% versus 19%) and extreme prolongation (6% versus 1%) in QTc were more frequent in those with HIV. Antiretroviral therapy was associated with lower odds of prolonged QTc (odds ratio [OR] = 0.35; P = .04), while methadone with higher odds (OR = 4.6; P = .01) in HIV-positive patients. With methadone and medication groups adjusted, HIV status was still associated with 17-millisecond longer QTc ( P = .04).ConclusionThis study provides evidence that patients with HIV may have clinically relevant longer QTc interval on ECG. Baseline and routine ECG monitoring may be warranted among patients living with HIV in clinical practice based on cumulative evidence.