Prevention of torsade de pointes in hospital settings: a scientific statement from the American Heart Association and the American College of Cardiology Foundation

Medical and physiological complications of exercise for individuals with an eating disorder: A narrative review

Individuals with eating disorders (ED) experience prolonged malnutrition, binge episodes, and compensatory behaviours that affect every organ system. Psychological and physiological symptoms are worsened with comorbid dysfunctional exercise, seen in up to 80% of those with an ED. Although return to exercise is an important component of treatment and recovery, little is known about the contraindications and risks of exercise engagement specific to those with an ED. This paper provides a comprehensive narrative review of the medical and physiological complications of engaging in exercise during ED treatment and outlines when exercise may be contraindicated or used in modified or cautionary ways. We conducted a literature search on MEDLINE, PubMed, and PsychArticles to identify relevant articles, which yielded six categories of medical and physiological complications of ED that may be exacerbated by exercise: energy availability, cardiovascular health, electrolyte abnormalities, biomedical function markers, sex hormones, and body composition. We summarize the evidence for these complications for readers and offer an initial set of recommendations for incorporating exercise during ED treatment based on our findings. This review may serve as a resource for members of ED treatment teams to help evaluate more readily and confidently whether exercise is safe for individual patients and when modifications and caution may be warranted.

QT interval dynamics in patients with ST-elevation MI

Background

An association between excessively prolonged QT and ventricular arrhythmia in patients with ST-elevation myocardial infarction has been described; however, the QT dynamics, characterization, and long-term predictive value are not well known.

Objective

To characterize QT interval dynamics in patients undergoing ST elevation myocardial infarction (STEMI) and determine its association with mortality.

Methods

A retrospective analysis of 4,936 consecutive patients, hospitalized for STEMI between 01/2013-12/2021. Patients with less than three electrocardiograms (ECGs) during index hospitalization were excluded. Baseline demographics, cardiovascular history, clinical risk factors, treatment measures, laboratory results, and mortality data were retrieved from the hospital's electronic medical records.

Results

We included 1,054 patients and 5,021 ECGs in our cohort with a median follow-up of 6 years [interquartile range (IQR) 4.3-7.4 years]. The QT was longer in women in comparison to men (428.6 ms ± 33.4 versus 419.8 ms ± 32.52, P-value = 0.001). QT prolongation was greater in females, elderly patients, and patients with STEMI caused by occlusion of the left anterior descending (LAD) coronary artery. We determined QT cutoff to be 445 ms. This value of QT divided our cohort upon arrival into a long QT group (217 patients, 26% of the cohort) and a "normal" QT group (835 patients, 74% of the cohort). The long QT group experienced an increase in combined short and long terms all-cause mortality. The QT upon arrival, on day 2 of hospitalization, and before discharge from the hospital, correlated with long-term mortality.

Conclusion

QT duration is often prolonged during STEMI; this prolongation is associated with increased mortality and adverse events. Gender is an important mediator of QT dynamics.

A case report of sudden cardiac arrest and torsade de pointes induced by the second-generation tyrosine kinase inhibitor dasatinib combined with fluconazole

A-41-year-old man diagnosed with acute myeloid leukemia (AML) survived dasatinib + fluconazole drug-induced long QT syndrome, sudden cardiac arrest, and torsade de pointes. Drug features and interaction jointly contributed to the whole process. Therefore, appropriate attention to drug interaction and close ECG monitoring are highly recommended for hospitalized patients, especially for those undergoing multi-drug regimens.

Prevalence and risk factors for acquired long QT syndrome in the emergency department: a retrospective observational study

BACKGROUND

Long QT syndrome (LQTS) is a heterogeneous syndrome that may be congenital or, more frequently, acquired. The real-world prevalence of acquired LQTS (aLQTS) in the emergency department (ED) remains to be determined. The aim of this study was to determine prevalence of aLQTS and its impact on symptoms on ED admissions.

METHODS

Electrocardiograms (ECG) of 5,056 consecutively patients admitted in the ED of a tertiary hospital between January 28th and March 17th of 2020 were reviewed. All patients with aLQTS were included. Clinical data with a focus on QT prolonging drugs and clinical factors were recorded. Statistical comparison was made between the groups with and without corrected QT (QTc) interval greater than 500 ms (value that is considered severely increased).

RESULTS

A total of 383 ECGs with prolonged QTc were recognized, corresponding to a prevalence of aLQTS at admission of 7.82%. Patients with aLQTS were more commonly men (53.3%) with an age of (73.49±14.79) years old and QTc interval of (505.3±32.4) ms. Only 20.4% of these patients with aLQTS were symptomatic. No ventricular arrhythmias were recorded. Patients with QT interval greater than 500 ms were more frequently female (59.5%; P<0.001) and were more frequently on QT prolonging drugs (77.3%; P=0.025). Main contributing factor was intake of antibiotics (odds ratio [OR] 4.680) followed by female gender (OR 2.473) and intake of antipsychotics (OR 1.925).

CONCLUSION

aLQTS is particularly prevalent in the ED. Female patients on antibiotics and antipsychotics are at particularly high risk. Efforts must be made to avoid, detect and treat aLQTS as early as possible.

Prediction of drug pro-arrhythmic cardiotoxicity using a semi-physiologically based pharmacokinetic model linked to cardiac ionic currents inhibition

Drug-induced torsades de pointes (TdP) risks are responsible for the withdrawal of many drugs from the market. Nowadays, assessments of drug-induced TdP risks are mainly based on maximum effective free therapeutic plasma concentration (EFTPCmax) and cardiac ionic current inhibitions using the human ventricular myocytes model (Tor-ORd model). Myocytes are targets of drug-induced TdP. The TdP risks may be directly linked to myocyte drug concentrations. We aimed to develop a semi-physiologically based pharmacokinetic (Semi-PBPK) model linked to cardiac ionic current inhibition (pharmacodynamics, PD) (Semi-PBPK-PD) to simultaneously predict myocyte drug concentrations and their TdP risks in humans. Alterations in action potential duration (ΔAPD90) were simulated using the Tor-ORd model and ionic current inhibition parameters based on myocyte or plasma drug concentrations. The predicted ΔAPD90 values were translated into in vivo alterations in QT interval(ΔQTc) induced by moxifloxacin, dofetilide, or sotalol. Myocyte drug concentrations of moxifloxacin, dofetilide, and sotalol gave better predictions of ΔQTc than plasma. Following validating the developed semi-PBPK-PD model, TdP risks of 37 drugs were assessed using ΔAPD90 and early afterdepolarization occurrence, which were estimated based on 10 × EFTPCmax and 10 × EFTMCmax (maximum effective free therapeutic myocyte concentration). 10 × EFTMCmax gave more sensitive and accurate predictions of pro-arrhythmic cardiotoxicity and the predicted TdP risks were also closer to clinic practice than 10 × EFTPCmax. In conclusion, pharmacokinetics and TdP risks of 37 drugs were successfully predicted using the semi-PBPK-PD model. Myocyte drug concentrations gave better predictions of ΔQTc and TdP risks than plasma.

Management of opioid use disorder and associated conditions among hospitalized adults: A Consensus Statement from the Society of Hospital Medicine

Hospital-based clinicians frequently care for patients with opioid withdrawal or opioid use disorder (OUD) and are well-positioned to identify and initiate treatment for these patients. With rising numbers of hospitalizations related to opioid use and opioid-related overdose, the Society of Hospital Medicine convened a working group to develop a Consensus Statement on the management of OUD and associated conditions among hospitalized adults. The guidance statement is intended for clinicians practicing medicine in the inpatient setting (e.g., hospitalists, primary care physicians, family physicians, advanced practice nurses, and physician assistants) and is intended to apply to hospitalized adults at risk for, or diagnosed with, OUD. To develop the Consensus Statement, the working group conducted a systematic review of relevant guidelines and composed a draft statement based on extracted recommendations. Next, the working group obtained feedback on the draft statement from external experts in addiction medicine, SHM members, professional societies, harm reduction organizations and advocacy groups, and peer reviewers. The iterative development process resulted in a final Consensus Statement consisting of 18 recommendations covering the following topics: (1) identification and treatment of OUD and opioid withdrawal, (2) perioperative and acute pain management in patients with OUD, and (3) methods to optimize care transitions at hospital discharge for patients with OUD. Most recommendations in the Consensus Statement were derived from guidelines based on observational studies and expert consensus. Due to the lack of rigorous evidence supporting key aspects of OUD-related care, the working group identified important issues necessitating future research and exploration.

Use of Electrocardiogram Monitoring in Adult Patients Taking High-Risk QT Interval Prolonging Medicines in Clinical Practice: Systematic Review and Meta-analysis

Introduction

Electrocardiogram (ECG) monitoring is an important tool to detect and mitigate the risk of potentially fatal drug-induced QT prolongation and remains fundamental in supporting the quality use of high-risk QT interval prolonging medicines.

Objective

The aim of this systematic review was to determine the prevalence of baseline and/or follow-up ECG use in adult patients taking high-risk QT interval prolonging medicines in clinical practice.

Methods

CINAHL, Cochrane Library, Embase, PubMed, EThOS, OpenGrey and Proquest were searched for studies in adults that reported ECG use at baseline and/or at follow-up in relation to the initiation of a high-risk QT interval prolonging medicine in any clinical setting; either hospital or non-hospital. Two reviewers independently assessed the methodological quality of included studies. Proportional meta-analysis was conducted with all studies reporting baseline ECG use, before medicine initiation, and follow-up ECG use, within 30 days of medicine initiation.

Results

There was variability in baseline ECG use according to the practice setting. The prevalence of baseline ECG use for high-risk QT interval prolonging medicines was moderate to high in the hospital setting at 75.1% (95% CI 64.3–84.5); however, the prevalence of baseline ECG use was low in the non-hospital setting at 33.7% (95% CI 25.8–42.2). The prevalence of follow-up ECG use was low to moderate in the hospital setting at 39.2% (95% CI 28.2–50.8) and could not be determined for the non-hospital setting.

Conclusions

The use of ECG monitoring for high-risk QT interval prolonging medicines is strongly influenced by the clinical practice setting. Baseline ECG use occurs more in the hospital setting in comparison to the non-hospital setting. There is lower use of follow-up ECG in comparison to baseline ECG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-022-01215-x.

Electrocardiographic abnormalities in childhood cancer survivors treated with cardiotoxic therapy: a systematic review

PURPOSE

The purpose of this study is to assess the available literature on the prevalence and risk factors of electrocardiographic (ECG) abnormalities after cardiotoxic treatment in childhood cancer survivors (CCS).

METHODS

A literature search was performed within MEDLINE, EMBASE, and CENTRAL (1966-11/2020) and reference lists of relevant studies. Studies were eligible for inclusion if they reported ECG abnormalities ≥2 years after cancer diagnosis in ≥50 CCS treated with anthracyclines, RT involving the heart region and/or mitoxantrone. Information about population, treatment, outcome, and risk factors were extracted and risk of bias was assessed.

RESULTS

Of 934 identified publications, 10 studies were included. Outcome definitions, treatment regimens, follow-up period, and risk of bias varied. These ECG abnormalities and prevalences were reported: major (5%-23%) and minor (12%) abnormalities according to the Minnesota Code, rhythm abnormalities (0%-12%), conduction abnormalities (0.3%-7.1%), depolarization abnormalities (0%), and repolarization abnormalities (0%-65%). The reported risk factors of ECG abnormalities (two studies) are male sex, anthracyclines, RT involving the heart region, and hypertension, although results were not univocal between studies and abnormalities.

CONCLUSIONS

Multiple ECG abnormalities have been described in CCS ≥2 years from diagnosis, some of which can have important implications. Future research is needed to evaluate the exact long-term incidence and risk factors, and to investigate their clinical relevance and relation with cardiac dysfunction or future cardiac events. This could improve cardiac surveillance for CCS.

Subtle QRS changes are associated with reduced ejection fraction, diastolic dysfunction, and heart failure development and therapy responsiveness: Applications for artificial intelligence to ECG

BACKGROUND

Since the last century, the electrocardiogram (ECG) remains the non-invasive test, that is, most easily accessible, feasible, and inexpensive for cardiology assessment. In past years, many novel ECG indexes and patterns have been published that allow for a more advanced evaluation of what is currently being done, especially based on subtle QRS changes and patterns.

OBJECTIVE

The objective of the study was to provide an update on the evidence and clinical applications of these ECG subtle QRS changes and patterns associated with heart disease.

METHODS

Through the literature review, we will highlight the subtle QRS changes and patterns associated with heart disease, mainly focusing on QRS duration, voltage, morphology, axis, and QT interval.

RESULTS

Small increases in QRS duration are associated with a reduction in left ventricular ejection fraction (EF), increased cardiac chamber dimensions, and risk for incident heart failure (HF). Moreover, fragmentation of the QRS complex is associated with myocardial fibrosis and is a substrate for developing arrhythmic events. Besides, low amplitude QRS voltage is associated with congestive HF, and an increase in the voltage of the QRS complexes is associated with the effectiveness of diuresis treatment. Furthermore, small increases in QT interval are associated with diastolic dysfunction due to impaired sarcoplasmic reticulum calcium handling as occurs in myocardial ischemia, hypertension, or diabetes. On the other hand, in patients with left ventricular dysfunction, the QRS area is associated with clinical and echocardiographic response to cardiac resynchronization therapy regardless of the type of bundle branch block. In addition, subtle ECG changes and patterns in the left bundle branch block are associated with concomitant right ventricular dilation, mostly based on the QRS axis and voltage. Notwithstanding, to identify these subtle changes in QRS require exact manual measurements that can take time. In this regard, applying artificial intelligence (AI) to the ECG can make a quicker and more complete assessment, as well as provide a low cost when applied to large populations.

CONCLUSION

We provided an update on the evidence and clinical applications of these subtle QRS changes and patterns associated with diastolic dysfunction, reduced EF, and HF development and therapy responsiveness, as well as their applications for AI to ECG.

False Negative ECG Device Results May Increase the Risk of Adverse Events in Clinical Oncology Trials

Background

Sites participating in clinical trials may not have the expertise and infrastructure to accurately measure cardiac intervals on 12-lead ECGs and rely heavily on the automated ECG device generated results for clinical decision-making.

Methods

Using a dataset of over 260,000 ECGs collected in clinical oncology studies, we investigated the mean difference and the rate of false negative results between the digital ECG machine QTc and QRS measurements compared to those obtained by a centralized ECG core lab.

Results

The mean differences between the core lab and the automated algorithm QTcF and QRS measurements were + 1.8 ± 16.0 ms and − 1.0 ± 8.8 ms, respectively. Among the ECGs with a centralized QTcF value > 450 or > 470 ms, 39.5% and 47.8% respectively had a device reported QTcF value ≤ 450 ms or ≤ 470 ms. Among the ECGs with a centrally measured QTcF > 500 ms, 55.8% had a device reported value ≤ 500 ms. Automated QTcF measurements failed to detect a QTcF increase > 60 ms for 53.9% of the ECGs identified by the core lab. Automated measurements also failed to detect QRS prolongation, though to a lesser extent than failures to detect QTc prolongation. Among the ECGs with a centrally measured QRS > 110 or 120 ms, 7.9% and 7.3% respectively had a device reported QRS value ≤ 110 ms or ≤ 120 ms.

Conclusion

Relying on automated measurements from ECG devices for patient inclusion and treatment (dis)continuation decisions poses a potential risk to patients participating in oncology studies.

C-reactive Protein Elevation Is Associated With QTc Interval Prolongation in Patients Hospitalized With COVID-19

Background

The relationship between inflammation and corrected QT (QTc) interval prolongation is currently not well defined in patients with COVID-19.

Objective

This study aimed to assess the effect of marked interval changes in the inflammatory marker C-reactive protein (CRP) on QTc interval in patients hospitalized with COVID-19.

Methods

In this retrospective cohort study of hospitalized adult patients admitted with COVID-19 infection, we identified 85 patients who had markedly elevated CRP levels and serial measurements of an ECG and CRP during the same admission. We compared mean QTc interval duration, and other clinical and ECG characteristics between times when CRP values were high and low. We performed mixed-effects linear regression analysis to identify associations between CRP levels and QTc interval in univariable and adjusted models.

Results

Mean age was 58 ± 16 years, of which 39% were women, 41% were Black, and 25% were White. On average, the QTc interval calculated via the Bazett formula was 15 ms higher when the CRP values were “high” vs. “low” [447 ms (IQR 427–472 ms) and 432 ms (IQR 412–452 ms), respectively]. A 100 mg/L increase in CRP was associated with a 1.5 ms increase in QTc interval [β coefficient 0.15, 95% CI (0.06–0.24). In a fully adjusted model for sociodemographic, ECG, and clinical factors, the association remained significant (β coefficient 0.14, 95% CI 0.05–0.23).

Conclusion

An interval QTc interval prolongation is observed with a marked elevation in CRP levels in patients with COVID-19.

QT Interval Prolongation Is a Novel Predictor of 1-Year Mortality in Patients With COVID-19 Infection

Background

QT interval prolongation is common in critically ill patients and is associated with increased mortality. However, the predictive value of a prolonged corrected QT interval (QTc) for myocardial injury and long-term mortality among patients hospitalized with COVID-19 infection is not well known.

Purpose

To evaluate the association of prolonged QTc with myocardial injury and with 1-year mortality among patients hospitalized with COVID-19 infection.

Materials and Methods

A total of 335 consecutive patients hospitalized with COVID-19 infection were prospectively studied. All patients underwent a comprehensive echocardiographic evaluation within 48 h from admission. Using the Bazett formula, the QTc interval was calculated from the first ECG tracing recorded at the ER. QTc ≥ 440 ms in males and ≥450 ms in females was considered prolonged. Patients with elevated cardiac biomarkers and/or echocardiographic signs of myocardial dysfunction were considered to have myocardial injury. The predictive value of QTc prolongation for myocardial injury was calculated using a multivariate binary regression model. One-year mortality rate of patients with and without QTc prolongation was compared using the log-rank test, and a multivariate Cox regression model adjusting for multiple covariates was performed to evaluate the 1-year mortality risk.

Results

One-hundred and nine (32.5%) patients had a prolonged QTc. Compared to patients without QTc prolongation, patients with prolonged QTc were older (70 ± 14.4 vs. 62.7 ± 16.6, p < 0.001), had more comorbidities, and presented with a more severe disease. Prolonged QTc was an independent predictor for severe or critical disease (adjusted HR 2.14, 95% CI 1.3-3.5; p = 0.002) and myocardial injury (adjusted HR 2.07, 95% CI 1.22-3.5; p = 0.007). One-year mortality of patients with prolonged QTc was higher than those with no QTc prolongation (40.4% vs. 15.5; p < 0.001). Following adjustment to multiple covariates including myocardial injury and disease severity, QTc prolongation was found to be associated with increased 1-year mortality risk (HR 1.69, 95% CI 1.06-2.68, p = 0.027).

Conclusion

Prolonged QTc is associated with disease severity, myocardial injury and 1-year mortality among patients hospitalized with COVID-19 infection.

QTc Prolongation with the Use of Hydroxychloroquine and Concomitant Arrhythmogenic Medications: A Retrospective Study Using Electronic Health Records Data

Introduction

Hydroxychloroquine can induce QT/QTc interval prolongation for some patients; however, little is known about its interactions with other QT-prolonging drugs.

Objective

The purpose of this retrospective electronic health records study was to evaluate changes in the QTc interval in patients taking hydroxychloroquine with or without concomitant QT-prolonging medications.

Methods

De-identified health records were obtained from the Cerner Health Facts^® database. Variables of interest included demographics, diagnoses, clinical procedures, laboratory tests, and medications. Patients were categorized into six cohorts based on exposure to hydroxychloroquine, methotrexate, or sulfasalazine alone, or the combination of any those drugs with any concomitant drug known to prolong the QT interval. Tisdale QTc risk score was calculated for each patient cohort. Two-sample paired t-tests were used to test differences between the mean before and after QTc measurements within each group and ANOVA was used to test for significant differences across the cohort means.

Results

A statistically significant increase in QTc interval from the last measurement prior to concomitant exposure of 18.0 ms (95% CI 3.5–32.5; p < 0.05) was found in the hydroxychloroquine monotherapy cohort. QTc changes varied considerably across cohorts, with standard deviations ranging from 40.9 (hydroxychloroquine monotherapy) to 57.8 (hydroxychloroquine + sulfasalazine). There was no difference in QTc measurements among cohorts. The hydroxychloroquine + QTc-prolonging agent cohort had the highest average Tisdale Risk Score compared with those without concomitant exposure (p < 0.05).

Conclusion

Our analysis of retrospective electronic health records found hydroxychloroquine to be associated with a moderate increase in the QTc interval compared with sulfasalazine or methotrexate. However, the QTc was not significantly increased with concomitant exposure to other drugs known to increase QTc interval.

The genetics of drug-induced QT prolongation: evaluating the evidence for pharmacodynamic variants

Drug-induced long QT syndrome (diLQTS) is an adverse effect of many commonly prescribed drugs, and it can increase the risk for lethal ventricular arrhythmias. Genetic variants in pharmacodynamic genes have been associated with diLQTS, but the strength of the evidence for each of those variants has not yet been evaluated. Therefore, the purpose of this review was to evaluate the strength of the evidence for pharmacodynamic genetic variants associated with diLQTS using a novel, semiquantitative scoring system modified from the approach used for congenital LQTS. KCNE1-D85N and KCNE2-T8A had definitive and strong evidence for diLQTS, respectively. The high level of evidence for these variants supports current consideration as risk factors for patients that will be prescribed a QT-prolonging drug.

Interleukin-6 Elevation Is a Key Pathogenic Factor Underlying COVID-19-Associated Heart Rate-Corrected QT Interval Prolongation

Background

Heart rate-corrected QT interval (QTc) prolongation is prevalent in patients with severe coronavirus disease 2019 (COVID-19) and is associated with poor outcomes. Recent evidence suggests that the exaggerated host immune-inflammatory response characterizing the disease, specifically interleukin-6 (IL-6) increase, may have an important role, possibly via direct effects on cardiac electrophysiology. The aim of this study was to dissect the short-term discrete impact of IL-6 elevation on QTc in patients with severe COVID-19 infection and explore the underlying mechanisms.

Methods

We investigated the following mechanisms: (1) the QTc duration in patients with COVID-19 during the active phase and recovery, and its association with C-reactive protein (CRP) and IL-6 levels; (2) the acute impact of IL-6 administration on QTc in an in vivo guinea pig model; and (3) the electrophysiological effects of IL-6 on ventricular myocytes in vitro.

Results

In patients with active severe COVID-19 and elevated IL-6 levels, regardless of acute myocardial injury/strain and concomitant QT-prolonging risk factors, QTc was significantly prolonged and rapidly normalized in correlation with IL-6 decrease. The direct administration of IL-6 in an in vivo guinea pig model acutely prolongs QTc duration. Moreover, ventricular myocytes incubated in vitro with IL-6 show evident prolongation in the action potential, along with significant inhibition in the rapid delayed rectifier potassium current (I_Kr).

Conclusion

For the first time, we demonstrated that in severe COVID-19, systemic inflammatory activation can per se promote QTc prolongation via IL-6 elevation, leading to ventricular electric remodeling. Despite being transitory, such modifications may significantly contribute to arrhythmic events and associated poor outcomes in COVID-19. These findings provide a further rationale for current anti-inflammatory treatments for COVID-19, including IL-6-targeted therapies.

Ventricular fibrillation during carotid endarterectomy and bailout stenting: a case report

Background

Carotid artery manipulation is not a special technique but reports of intraoperative ventricular fibrillation are rare. The risk of fatal arrhythmias may be hidden behind routine surgical techniques and anesthetic management. We focused on QT prolongation and QT dispersion.

Case presentation

A 77-year-old man underwent carotid endarterectomy and bailout stenting. Although there were no obvious preoperative risk factors for intraoperative ventricular tachyarrhythmia, ventricular fibrillation (VF) had occurred during a maneuver of the carotid artery under hypercapnia. QTc was prolonged from 317 ms before surgery to 458 ms before the onset of VF. QTc dispersion between leads II and III was also increased to 50 ms. Hypomagnesemia was noted after resuscitation by electrical defibrillation, adrenaline, and noradrenaline.

Conclusions

We considered that the combination of multiple risk factors led to the development of ventricular fibrillation. It should be noted that carotid artery manipulation has the potential to cause arrhythmias.

A pharmacogenomic investigation of the cardiac safety profile of ondansetron in children and pregnant women

BACKGROUND

Ondansetron is a highly effective antiemetic for the treatment of nausea and vomiting. However, this medication has also been associated with QT prolongation. Pharmacogenomic information on therapeutic response to ondansetron exists, but no investigation has been performed on genetic factors that influence the cardiac safety of this medication.

METHODS

Three patient groups receiving ondansetron were recruited and followed prospectively (pediatric post-surgical patients n = 101; pediatric oncology patients n = 98; pregnant women n = 62). Electrocardiograms were conducted at baseline, and 5- and 30-min post-ondansetron administration, to determine the effect of ondansetron treatment on QT interval. Pharmacogenomic associations were assessed via analyses of comprehensive CYP2D6 genotyping and genome-wide association study data.

RESULTS

In the entire cohort, 62 patients (24.1%) met the criteria for prolonged QT, with 1.2% of the cohort exhibiting unsafe QT prolongation. The most significant shift from baseline occurred at five minutes post-ondansetron administration (P = 9.8 × 10^-4). CYP2D6 activity score was not associated with prolonged QT. Genome-wide analyses identified novel associations with a missense variant in TLR3 (rs3775291; P = 2.00 × 10^-7) and a variant linked to the expression of SLC36A1 (rs34124313; P = 1.97 × 10^-7).

CONCLUSIONS

This study has provided insight into the genomic basis of ondansetron-induced cardiac changes and has emphasized the importance of genes that have been implicated in serotonin-related traits. These biologically-relevant findings represent the first step towards understanding this adverse event with the overall goal to improve the safety of this commonly used antiemetic medication.

Defining cardiovascular toxicities of cancer therapies: an International Cardio-Oncology Society (IC-OS) consensus statement

The discipline of Cardio-Oncology has seen tremendous growth over the past decade. It is devoted to the cardiovascular (CV) care of the cancer patient, especially to the mitigation and management of CV complications or toxicities of cancer therapies, which can have profound implications on prognosis. To that effect, many studies have assessed CV toxicities in patients undergoing various types of cancer therapies; however, direct comparisons have proven difficult due to lack of uniformity in CV toxicity endpoints. Similarly, in clinical practice, there can be substantial differences in the understanding of what constitutes CV toxicity, which can lead to significant variation in patient management and outcomes. This document addresses these issues and provides consensus definitions for the most commonly reported CV toxicities, including cardiomyopathy/heart failure and myocarditis, vascular toxicity, and hypertension, as well as arrhythmias and QTc prolongation. The current document reflects a harmonizing review of the current landscape in CV toxicities and the definitions used to define these. This consensus effort aims to provide a structure for definitions of CV toxicity in the clinic and for future research. It will be important to link the definitions outlined herein to outcomes in clinical practice and CV endpoints in clinical trials. It should facilitate communication across various disciplines to improve clinical outcomes for cancer patients with CV diseases.

Effect of Replacing Vendor QTc Alerts with a Custom QTc Risk Alert in Inpatients

OBJECTIVE

The aim of the study is to implement a customized QTc interval clinical decision support (CDS) alert strategy in our electronic health record for hospitalized patients and aimed at providers with the following objectives: minimize QTc prolongation, minimize exposure to QTc prolonging medications, and decrease overall QTc-related alerts. A strategy that was based on the validated QTc risk scoring tool and replacing medication knowledge vendor alerts with custom QTc prolongation alerts was implemented.

METHODS

This is a retrospective quasi-experimental study with a pre-intervention period (August 2019 to October 2019) and post-intervention period (December 2019 to February 2020). The custom alert was implemented in November 2019.

RESULTS

In the pre-implementation group, 361 (19.3%) patients developed QTc prolongation, and in the post-implementation group, 357 (19.6%) patients developed QTc prolongation (OR: 1.02, 95% CI: 0.87-1.20, p = 0.81). The odds ratio of an action taken post-implementation compared with pre-implementation was 18.90 (95% CI: 14.03-25.47, p <0. 001). There was also a decrease in total orders for QTc prolonging medications from 7,921 (5.5%) to 7,566 (5.3%) with an odds ratio of 0.96 (95% CI: 0.93-0.99, p = 0.01).

CONCLUSION

We were able to decrease patient exposure to QTc prolonging medications while not increasing the rate of QTc prolongation as well as improving alert action rate. Additionally, there was a decrease in QTc prolonging medication orders which illustrates the benefit of using a validated risk score with a customized CDS approach compared with a traditional vendor-based strategy. Further research is needed to confirm if an approach implemented at our organization can reduce QTc prolongation rates.

Mapping the Knowledge of Antipsychotics-Induced Sudden Cardiac Death: A Scientometric Analysis in CiteSpace and VOSviewer

The drugs on the market for schizophrenia are first-generation and second-generation antipsychotics. Some of the first-generation drugs have more side effects than the other drugs, so they are gradually no longer being applied clinically. Years of research have shown that the risk of sudden cardiac death in psychotic patients is associated with drug use, and antipsychotic drugs have certain cardiotoxicity and can induce arrhythmias. The mechanism of antipsychotic-induced sudden cardiac death is complicated. Highly cited papers are among the most commonly used indicators for measuring scientific excellence. This article presents a high-level analysis of highly cited papers using Web of Science core collection databases, scientometrics methods, and thematic clusters. Temporal dynamics of focus topics are identified using a collaborative network (author, institution, thematic clusters, and temporal dynamics of focus topics are identified), keyword co-occurrence analysis, co-citation clustering, and keyword evolution. The primary purpose of this study is to discuss the visual results, summarize the research progress, and predict the future research trends by bibliometric methods of CiteSpace and VOSviewer. This study showed that a research hotspot is that the mechanisms of cardiotoxicity, the safety monitoring, and the assessment of the risk-benefit during clinical use of some newer antipsychotics, clozapine and olanzapine. We discussed relevant key articles briefly and provided ideas for future research directions for more researchers to conduct related research.

Estimation of cardiac QTc intervals in people prescribed antipsychotics: a comparison of correction factors

BACKGROUND

A prolonged electrocardiogram (ECG) QT interval is associated with cardiac events and increased mortality. Antipsychotics can prolong the QT interval. The QT interval requires correction (QTc) for heart rate using a formula or QT-nomogram. The QT and QTc can be calculated automatically by the ECG machine or manually; however, machine-measured QT(c) intervals may be inaccurate.

OBJECTIVE

We aimed to investigate the mean QTc and proportion of prolonged QTc intervals in people taking antipsychotic medicines.

METHODS

We conducted an observational retrospective chart review and data analysis of all consecutive patients taking antipsychotics, with an ECG record, admitted to the psychiatric unit of a large tertiary hospital in Brisbane, Australia, between 1 January 2017 and 30 January 2019. We investigated the mean QTc of people taking antipsychotics to determine differences using (a) machine versus manual QT interval measurement and (b) QTc correction formulae (Bazett, Fridericia, Framingham, Hodges and Rautaharju) and the QT-nomogram. We also determined the number of people with a prolonged QTc using different methods and compared rates of prolonged QTc with antipsychotic monotherapy and polypharmacy.

RESULTS

Of 920 included people, the mean (±SD) machine-measured, Bazett-corrected QT interval (recorded from the ECG) was 435 ms (±27), significantly longer (p < 0.001) than the mean manually measured corrected QT intervals with Fridericia 394 ms (±24), Framingham 395 ms (±22), Hodges 398 ms (±22) and Rautaharju 400 ms (±24) formulae. There were significantly more people with a prolonged QTc using machine-measured QT and the Bazett formula (12.0%, 110/920) when compared with manually measured QT and the Fridericia formula (2.2%, 20/920) or QT-nomogram (0.7%, 6/920). Rates of QTc prolongation did not differ between people taking antipsychotic polypharmacy compared with monotherapy.

CONCLUSION

Machine-measured QTc using the Bazett formula overestimates the QTc interval length and number of people with a prolonged QTc, compared with other formulae and the QT-nomogram. We recommend manually measuring the QT and correcting with the Fridericia formula or QT-nomogram prior to modifying antipsychotic therapies.

A Novel Frameshift Mutation, KCNH2 [p.Asp896ArgfsX79], Leading to Malignant Ventricular Arrhythmia, Identified After Treatment of Gastrointestinal Bleeding

A novel frameshift mutation in the KCNH2 gene for long QT syndrome type 2 (LQTS2) was identified after torsades des pointes ventricular tachycardia in a 49-year-old patient managed with octreotide and nadolol for an acute variceal bleed. In spite of removal of offending medications, and correction of underlying electrolyte abnormalities, the patient’s QT interval remained prolonged—at 521 ms—raising the suspicion of an underlying channelopathy. Genetic studies confirmed heterozygosity for a novel frameshift mutation for the KCNH2 gene, D896Rfs X79. We explore the pathogenicity and clinical impact of this variant mutation.

QTc prolongation in patients with COVID-19: a retrospective chart review

Drug-induced corrected QT (QTc) prolongation can cause Torsade de Pointes (TdP) which leads to severe arrhythmia or sudden cardiac death. However, information on the prevalence of QTc prolongation in coronavirus disease 2019 (COVID-19) patients and risk factors is limited. A retrospective chart review was conducted in COVID-19 patients admitted to Chonburi Hospital from April to October 2020. The outcomes were the incidence of QTc prolongation and prevalence of risk factor QTc prolongation. We included 29 COVID-19 patients. After treatments were initiated, QTc prolongation occurred in 17 patients (58.62%). QT prolongation could be found as early as two days after the treatment initiation (median = 6 days interquartile range [IQR], 4-7). The median QTc interval in those 17 patients increased from 410 (IQR, 399.5-425.0) ms to 460 (453.50-466.50) ms, with the maximum QTc interval of 488 ms. They were treated with multiple drugs that were reported as a cause of QTc prolongation. 64.71% (n = 11) of them were treated with chloroquine. The median TdP risk score in patients with and without QTc prolongation was 3 (IQR, 2-3) and 2 (IQR, 1-2), respectively. The percentage of patients with comorbidities including atrial fibrillation, bradycardia, concomitant use of diuretics, diabetes, electrolyte imbalance was higher in patients with QTc prolongation. COVID-19 patients were treated with multiple drugs that were reported as a cause of QTc prolongation. COVID-19 patients with QTc prolongation had more comorbidities that are risk factors for QTc prolongation.

QT interval measurement in ventricular pacing: Implications for assessment of drug effects and pro-arrhythmia risk

QT interval prolongation is a known risk factor for development of malignant ventricular arrhythmias. Measurement of the QT interval is difficult in the setting of ventricular pacing (VP), which can prolong depolarization and increase the QT interval, overestimating repolarization time. VP and cardiac resynchronization therapies have become commonplace in modern cardiac care and may contribute to repolarization heterogeneity and subsequent increased risk for ventricular arrhythmias including Torsades de Pointes. It is imperative for the clinician caring for acutely ill cardiac patients to understand the relationship between QT interval prolongation, both drug-induced and pacing-induced, and repolarization changes with subsequent ventricular arrhythmia risk. In this review, we discuss the components of QT interval assessment for arrhythmogenic risk including arrhythmogenic QT prolongation, methods for adjusting the QT interval to identify repolarization changes, methods to adjust for heart rate, and propose a framework for medication management to assess for drug-induced long QT syndrome in patients with VP.

A Systematic Review on the Therapeutic Relevance of Hydroxychloroquine/Chloroquine in the Management of COVID-19

Background

The coronavirus disease-2019 (COVID-19) pandemic is coming to the fore and has surfaced as a public health emergency of international concern. The lack of vaccines or an effective treatment has led to the global hunt for potential pharmaceuticals in adequately managing this disease. This systematic review highlights the efficacy of chloroquine and its derivative hydroxychloroquine in the treatment of COVID-19 and also explores the safety profile of these drugs.

Methods

EMBASE, COCHRANE, and PubMed databases were searched for studies on the use of hydroxychloroquine or chloroquine in the treatment of COVID-19.

Results

Twenty articles were selected including expert opinions, National Guidelines, three small randomized controlled trials, and one prospective study. Both hydroxychloroquine and chloroquine have shown promising results including reduction in hospital length of stay and overall mortality. Moreover, concomitant use with azithromycin seems to reduce viral load to a greater extent.

Conclusions

Considering the known safety profile of these drugs in the treatment of other diseases, their availability and affordability, chloroquine and hydroxychloroquine are potential antiviral agents in the treatment of COVID-19. However, reported side effects of these drugs when used in conjunction with azithromycin in patients with comorbidities have raised significant safety concerns. High-quality randomized clinical trials are warranted to provide more comprehensive evidence of the safety of these drugs in patients infected with COVID-19.

Implementation of a Pharmacist Monitoring Process for Patients on QTc Prolonging Antibiotics: A Pilot Study

Purpose: The purpose of this pilot study was to implement a pharmacist monitoring process for 4 antimicrobials; azithromycin, ciprofloxacin, levofloxacin, and fluconazole. This pilot study was a patient safety initiative to screen patients and engage providers about therapies at risk for QT prolongation. Methodology: A concurrent chart review was performed at a single center from January 6, to February 22, 2020, of adult patients ≥ 18 years of age initiated on azithromycin, ciprofloxacin, levofloxacin, and fluconazole. Patient risk factors assessed: age, female sex, loop diuretic use, potassium ≤ 3.5 mEq/L, QTc ≥ 450 ms, acute myocardial infarction (MI) or heart failure, 1 or more QTc prolonging agents, and sepsis. The primary endpoint was successful implementation of the QTc monitoring process by pharmacists. Secondary endpoints were the interventions made by pharmacists. Results: From January 6, to February 22, 2020, there were a total of 412 orders for one of the target antimicrobials that resulted in 157 documented pharmacist reviews (38.1%). Of the 157 evaluations, 100 of these represented patients in our high risk group (84 moderate, 16 high risk). Successful implementation was observed through documentation of assessment on all patients with moderate or high risk scores in the 100 person cohort. Conclusion: The pilot study demonstrated a successful implementation of a QTc monitoring process by pharmacists since all patients had documented reviews. Further steps include investigating how to improve efficiency, as well as ways for continued success in monitoring.

The myocardial and neuronal infectivity of SARS-CoV-2 and detrimental outcomes

The epidemiological outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), alias COVID-19, began in Wuhan, Hubei, China, in late December and eventually turned into a pandemic that has led to over 3.71 million deaths and over 173 million infected cases worldwide. In addition to respiratory manifestations, COVID-19 patients with neurological and myocardial dysfunctions exhibit a higher risk of in-hospital mortality. The immune function tends to be affected by cardiovascular risk factors and is thus indirectly related to the prognosis of COVID-19 patients. Many neurological symptoms and manifestations have been reported in COVID-19 patients; however, detailed descriptions on the prevalence and characteristic features of these symptoms are restricted due to insufficient data. It is thus advisable for clinicians to be vigilant for both cardiovascular and neurological manifestations to detect them at an early stage to avoid inappropriate management of COVID-19 and to address the manifestations adequately. Patients with severe COVID-19 are notably more susceptible to developing cardiovascular and neurological complications than non-severe COVID-19 patients. This review focuses on the consequential outcomes of COVID-19 on cardiovascular and neuronal functions, including other influencing factors.

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

BACKGROUND

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.

OBJECTIVE

To compare the diagnostic performance of QTc values obtained with cardiac telemetry versus electrocardiography.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Use of ECG monitoring for adult patients taking high-risk QT interval-prolonging drugs in clinical practice: a systematic review protocol

OBJECTIVE

The objective of this review is to determine the rates of electrocardiogram use in adult patients taking high-risk QT interval-prolonging drugs in clinical settings. This review will determine the extent of ECG monitoring being used to mitigate the risk of drug-induced QT prolongation.

INTRODUCTION

High-risk QT interval-prolonging drugs pose a well-established risk of cardiac arrhythmia, including torsades de pointes, among other serious long QT syndromes, which can be fatal. Detection and mitigation of QT prolongation involves use of electrocardiogram monitoring. This systematic review will present evidence for uptake of electrocardiogram monitoring in clinical practice to support the quality use of high-risk QT interval-prolonging drugs.

INCLUSION CRITERIA

Quantitative studies, published from 2004 that determine the rate of electrocardiogram monitoring before and during use of high-risk QT interval-prolonging drugs in adults 18 years or older, either in community or hospital settings, will be eligible for inclusion.

METHODS

CINAHL, Cochrane Library, Embase, and PubMed will be searched to identify published studies. EThOS, OpenGrey, and ProQuest Dissertations and Theses will be searched to identify unpublished studies. Conference abstracts will be excluded. There will be no restriction on country or language. Two reviewers will independently screen and select studies, assess methodological quality, and extract data. The JBI approach to systematic reviews of prevalence and incidence will be followed. Meta-analysis will be performed, if possible, and the Grading of Recommendations Assessment Development and Evaluation (GRADE) Summary of Findings presented.

Incidence of adverse reaction of drugs used in COVID-19 management: a retrospective, observational study

Background

An urgent need for coronavirus infectious disease (COVID-19) treatment has resulted in off-label drug use. Although previous studies had investigated the adverse drug reaction (ADR) of the medications for COVID-19 in their respective local settings, the safety profile in a Malaysian setting remains unknown. Our study aims to establish the incidence of ADR for drugs used in COVID-19 management in a Malaysian tertiary hospital.

Methods

This retrospective observational study enrolled patients started on drugs for COVID-19 in Sungai Buloh Hospital from 1 March 2020 to 31 May 2020. The clinical staging of COVID-19 patients was decided by the treating physician in accordance with the Clinical Management of Confirmed COVID-19 Case in Adults (Annex 2E). Suspected ADRs were evaluated with a trigger tool of pre-defined laboratory values or the adverse events listed in the registered product insert. Causality assessment was conducted when an ADR was suspected using the World Health Organization-Uppsala Monitoring Centre (WHO-UMC) system, and only cases classified as certain, probable and possible ADR were considered. Data analysis was completed with descriptive, univariate and multivariate analysis.

Results

The study (N = 1,080) identified 217 patients (20.1%) who experienced ADR, with 246 adverse events detected. Most events were related to the gastrointestinal (43.5%), hepatobiliary (36.2%) and cardiac (16.3%) systems. The most commonly suspected drugs were atazanavir (52.7%), chloroquine (36.8%) and lopinavir/ritonavir (34.6%). The independent risk factors of ADR were female (adjusted odds ratio (OR): 1.53; 95% CI 1.06–2.20; P = 0.024), diagnosis of COVID-19 stage 3 (adjusted OR: 2.58; 95% CI 1.20–5.55; P = 0.015) and stage 4 (adjusted OR: 4.17; 95% CI 1.79–9.73; P = 0.001), and the number of COVID-19 drugs (adjusted OR: 3.34; 95% CI 2.51–4.44; P < 0.001). Only 49 adverse events (19.9%) were manually reported by healthcare professionals, with hyperbilirubinaemia (65.3%) and QT prolongation (28.6%) most frequently reported.

Conclusion

Medications used in COVID-19 management had resulted in one in five patients experiencing ADR. Our study has provided an overview on incidence of ADR for off-label use of medications used in COVID-19 management, which suggests a similar safety profile when used for FDA-approved indications.

Anti-Ro/SSA Antibodies and the Autoimmune Long-QT Syndrome

Autoimmunity is increasingly recognized as a novel pathogenic mechanism for cardiac arrhythmias. Several arrhythmogenic autoantibodies have been identified, cross-reacting with different types of surface proteins critically involved in the cardiomyocyte electrophysiology, primarily ion channels (autoimmune cardiac channelopathies). Specifically, some of these autoantibodies can prolong the action potential duration leading to acquired long-QT syndrome (LQTS), a condition known to increase the risk of life-threatening ventricular arrhythmias, particularly Torsades de Pointes (TdP). The most investigated form of autoimmune LQTS is associated with the presence of circulating anti-Ro/SSA-antibodies, frequently found in patients with autoimmune diseases (AD), but also in a significant proportion of apparently healthy subjects of the general population. Accumulating evidence indicates that anti-Ro/SSA-antibodies can markedly delay the ventricular repolarization via a direct inhibitory cross-reaction with the extracellular pore region of the human-ether-a-go-go-related (hERG) potassium channel, resulting in a higher propensity for anti-Ro/SSA-positive subjects to develop LQTS and ventricular arrhythmias/TdP. Recent population data demonstrate that the risk of LQTS in subjects with circulating anti-Ro/SSA antibodies is significantly increased independent of a history of overt AD, intriguingly suggesting that these autoantibodies may silently contribute to a number of cases of ventricular arrhythmias and cardiac arrest in the general population. In this review, we highlight the current knowledge in this topic providing complementary basic, clinical and population health perspectives.

Drug-Induced QTc Prolongation: What We Know and Where We Are Going

Drug-induced QTc prolongation is a concerning electrocardiogram (ECG) abnormality. This cardiac disturbance carries a 10% risk of sudden cardiac death due to the malignant arrhythmia, Torsades de Pointes. The Arizona Center for Education and Research on Therapeutics (AzCERT) has classified QTc prolonging therapeutic classes such as antiarrhythmics, antipsychotics, anti-infectives, and others. AzCERT criteria categorizes medications into three risk categories: "known," "possible," and "conditional risk" of QTc prolongation and Torsades de Pointes. The list of QTc prolonging medications continues to expand as new drug classes are approved and studied. Risk factors for QTc prolongation can be delineated into modifiable or non-modifiable. A validated risk scoring tool may be utilized to predict the likelihood of prolongation in patients receiving AzCERT classified medication. The resultant risk score may be applied to a clinical decision support system which offers mitigation strategies. Mitigation strategies including discontinuation of possible offending agents with selection of an alternative agent, assessment of potential drug interactions or dose adjustments through pharmacokinetic and pharmacodynamic monitoring, and initiation of both ECG and electrolyte monitoring are essential to prevent a drug-induced arrhythmia. The challenges presented by the COVID-19 pandemic have led to the development of innovative continuous monitoring technology, increasing protection for both patients and healthcare workers. Early intervention strategies may reduce adverse events and improve clinical outcomes in patients identified to be at risk of QTc prolongation.

Torsade de pointes: A nested case-control study in an integrated healthcare delivery system

Background

TdP is a form of polymorphic ventricular tachycardia which develops in the setting of a prolonged QT interval. There are limited data describing risk factors, treatment, and outcomes of this potentially fatal arrhythmia.

Objective

Our goals were as follows: (1) to validate cases presenting with Torsade de Pointes (TdP), (2) to identify modifiable risk factors, and (3) to describe the management strategies used for TdP and its prognosis in a real‐world healthcare setting.

Methods

Case–control study (with 2:1 matching on age, sex, and race/ethnicity) nested within the Genetic Epidemiology Research on Aging (GERA) cohort. Follow‐up of the cohort for case ascertainment was between January 01, 2005 and December 31, 2018.

Results

A total of 56 cases of TdP were confirmed (incidence rate = 3.6 per 100,000 persons/years). The average (SD) age of the TdP cases was 74 (13) years, 55 percent were female, and 16 percent were non‐white. The independent predictors of TdP were potassium concentration <3.6 mEq/L (OR = 10.6), prior history of atrial fibrillation/flutter (OR = 6.2), QTc >480 ms (OR = 4.4) and prior history of coronary artery disease (OR = 2.6). Exposure to furosemide and amiodarone was significantly greater in cases than in controls. The most common treatment for TdP was IV magnesium (78.6%) and IV potassium repletion (73.2%). The in‐hospital and 1‐year mortality rates for TdP cases were 10.7% and 25.0% percent, respectively.

Conclusions

These findings may inform quantitative multivariate risk indices for the prediction of TdP and could guide practitioners on which patients may qualify for continuous ECG monitoring and/or electrolyte replacement therapy.

Electroimmunology and cardiac arrhythmia

Conduction disorders and arrhythmias remain difficult to treat and are increasingly prevalent owing to the increasing age and body mass of the general population, because both are risk factors for arrhythmia. Many of the underlying conditions that give rise to arrhythmia - including atrial fibrillation and ventricular arrhythmia, which frequently occur in patients with acute myocardial ischaemia or heart failure - can have an inflammatory component. In the past, inflammation was viewed mostly as an epiphenomenon associated with arrhythmia; however, the recently discovered inflammatory and non-canonical functions of cardiac immune cells indicate that leukocytes can be arrhythmogenic either by altering tissue composition or by interacting with cardiomyocytes; for example, by changing their phenotype or perhaps even by directly interfering with conduction. In this Review, we discuss the electrophysiological properties of leukocytes and how these cells relate to conduction in the heart. Given the thematic parallels, we also summarize the interactions between immune cells and neural systems that influence information transfer, extrapolating findings from the field of neuroscience to the heart and defining common themes. We aim to bridge the knowledge gap between electrophysiology and immunology, to promote conceptual connections between these two fields and to explore promising opportunities for future research.

Genetic and Molecular Aspects of Drug-Induced QT Interval Prolongation

Long QT syndromes can be either acquired or congenital. Drugs are one of the many etiologies that may induce acquired long QT syndrome. In fact, many drugs frequently used in the clinical setting are a known risk factor for a prolonged QT interval, thus increasing the chances of developing torsade de pointes. The molecular mechanisms involved in the prolongation of the QT interval are common to most medications. However, there is considerable inter-individual variability in drug response, thus making the application of personalized medicine a relevant aspect in long QT syndrome, in order to evaluate the risk of every individual from a pharmacogenetic standpoint.

Proarrhythmia assessment in treatment with hydroxychloroquine and azithromycin hospitalized elderly COVID-19 patients - our experience

The aim of our study was to characterize the repolarization disorders propensity induced by drug-drug interaction. In this observational retrospective study, we report our experience on all elderly patients with ascertained diagnosis of coronavirus disease 2019 through nasopharyngeal swab with real time-polymerase chain reaction at our Pugliese-Ciaccio hospital in Catanzaro, who received hydroxychloroquine (HCQ), with or without azithromycin (AZY). 33 hospitalized patients were examined. We calculated QT value, cQT, QT dispersion, and cQT dispersion and examined possible progression on the basal electrocardiogram (T0) and after the insertion of the drug (T1). The QT value is increased by T0 vs T1 (370±40.74 vs 420±36.91 ms; P=0.000), as well as the cQT value (408±25.40 vs 451.54±58.81; P=0.003), the QT dispersion (QTd: 36.36±14.53 vs 50.90±13.12 ms; P=0.000); the dispersion of cQTc (cQTd 46.27±18.72 vs 63.18±21.93 ms; P=0.001). The ΔQT was 37.44±44.09 while the ΔcQT was 32.01±56.47). The main determinant of QTc prolongation is the number of drug at risk of prolongation of the QT that could influence the ventricular repolarization phase. The use of HCQ in combination with AZY, in patients suffering from severe acute respiratory syndrome-related coronavirus-2, can favor the onset of serious side effects, even potentially fatal. Finally, the measures of QTd and cQTd confirmed additional electrocardiographic parameters useful in identifying patients being treated with drugs at risk of potential adverse arrhythmic events following drug interaction.

QT Interval Monitoring with Handheld Heart Rhythm ECG Device in COVID-19 Patients

Background

QTc prolongation is an adverse effect of COVID-19 therapies. The use of a handheld device in this scenario has not been addressed.

Objectives

To evaluate the feasibility of QTc monitoring with a smart device in COVID-19 patients receiving QTc-interfering therapies.

Methods

Prospective study of consecutive COVID-19 patients treated with hydroxychloroquine ± azithromycin ± lopinavir-ritonavir. ECG monitoring was performed with 12-lead ECG or with KardiaMobile-6L. Both registries were also sequentially obtained in a cohort of healthy patients. We evaluated differences in QTc in COVID-19 patients between three different monitoring strategies: 12-lead ECG at baseline and follow-up (A), 12-lead ECG at baseline and follow-up with the smart device (B), and fully monitored with handheld 6-lead ECG (group C). Time needed to obtain an ECG registry was also documented.

Results

One hundred and eighty-two COVID-19 patients were included (A: 119(65.4%); B: 50(27.5%); C: 13(7.1%). QTc peak during hospitalization did significantly increase in all groups. No differences were observed between the three monitoring strategies in QTc prolongation (p = 0.864). In the control group, all but one ECG registry with the smart device allowed QTc measurement and mean QTc did not differ between both techniques (p = 0.612), displaying a moderate reliability (ICC 0.56 [0.19-0.76]). Time of ECG registry was significantly longer for the 12-lead ECG than for handheld device in both cohorts (p < 0.001).

Conclusion

QTc monitoring with KardiaMobile-6L in COVID-19 patients was feasible. Time of ECG registration was significantly lower with the smart device, which may offer an important advantage for prevention of virus dissemination among healthcare providers.

Acquired Long QT Syndrome and Torsades de Pointes after Mitral Valve Replacement Surgery

Acquired long QT syndrome (aLQTS) can occur in up to one third of patients undergoing cardiac surgery and is often undisclosed. We present a case of a 55-year-old male patient admitted to our center for mitral valve replacement surgery, and, during the postoperative period, a long QT greater than 600 ms was confirmed and in the Holter monitoring Torsade de Pointes (TdP) was evidenced. The patient received appropriate medical treatment and was discharge in stable clinical conditions.

Risk factors and predictors of QTc prolongation in critically ill Chinese patients

BACKGROUND

To recognize and validate the predictor of risk factors for ICU patients with QTc intervals ≥500 ms.

METHODS

We retrospectively reviewed 160 ICU patients with their medical electronic records including all demographic data, diagnosis measurements, ECGs and medication from March 1, 2018 to December 1, 2018. All information of patients' baseline, comorbidities, electrolytes and Long QT syndrome (LQTS)-inducing medications of patients with QT interval corrected (QTc) ≥ 500 ms (n = 80) and <500 ms (n = 80) were collected and analyzed using univariate and multivariate analyses to find predictors.

RESULTS

Comparing to patients with QTc < 500 ms, patients with QTc ≥ 500 ms had increased SOFA (P = 0.010) and APACHE II scores (P = 0.002), longer lengths of ICU stays (P < 0.001), greater incidence of congestive heart failure (P = 0.005) and more preset risk factors (P < 0.001). The frequency of administration of mosapride (P = 0.015), amiodarone (P = 0.027) and number of combined LQTS-inducing medications (P = 0.012) were greater in patients with QTc ≥ 500 ms than in those with QTc < 500 ms. But after multivariate analysis, we found that risk factors related to a QTc ≥ 500 ms were only congestive heart failure (OR: 5.28), number of combined LQTS-inducing medications (OR: 1.60) and APACHE II score (OR: 1.08).

CONCLUSIONS

For critically ill patients, congestive heart failure, number of combined LQTS-inducing medications and APACHE II score are proved as risk factors associated with QTc > 500 ms.

Development of a Patient-Specific p.D85N-Potassium Voltage-Gated Channel Subfamily E Member 1-Induced Pluripotent Stem Cell-Derived Cardiomyocyte Model for Drug-Induced Long QT Syndrome

BACKGROUND

Prior epidemiological studies demonstrated that the p.D85N-Potassium voltage-gated channel subfamily E member 1 (KCNE1) common variant reduces repolarization reserve and predisposes to drug-induced QT prolongation/torsades de pointes. We sought to develop a cellular model for drug-induced long QT syndrome using a patient-specific induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM).

METHODS

p.D85N-KCNE1 iPSCs were generated from a 23-year-old female with an exaggerated heart rate-corrected QT interval response to metoclopramide (ΔQTc of 160 ms). Clustered regularly interspaced short palindromic repeats-associated 9 technology was used to generate gene-corrected isogenic iPSCs. Field potential duration and action potential duration (APD) were measured from iPSC-CMs.

RESULTS

At baseline, p.D85N-KCNE1 iPSC-CMs displayed significantly longer field potential duration (281±15 ms, n=13 versus 223±8.6 ms, n=14, P<0.01) and action potential duration at 90% repolarization (APD90; 579±22 ms, n=24 versus 465±33 ms, n=26, P<0.01) than isogenic-control iPSC-CMs. Dofetilide at a concentration of 2 nM increased significantly field potential duration (379±20 ms, n=13, P<0.01) and APD90 (666±11 ms, n=46, P<0.01) in p.D85N-KCNE1 iPSC-CMs but not in isogenic-control. The effect of dofetilide on APD90 (616±54 ms, n=7 versus 526±54 ms, n=10, P<0.05) was confirmed by Patch-clamp. Interestingly, treatment of p.D85N-KCNE1 iPSC-CMs with estrogen at a concentration of 1 nM exaggerated further dofetilide-induced APD90 prolongation (696±9 ms, n=81, P<0.01) and caused more early afterdepolarizations (11.7%) compared with isogenic control (APD90: 618±8 ms, n=115 and early afterdepolarizations: 2.6%, P<0.05).

CONCLUSIONS

This iPSC-CM study provides further evidence that the p.D85N-KCNE1 common variant in combination with environmental factors such as QT prolonging drugs and female sex is proarrhythmic.

The Use of Intravenous Lidocaine in the Setting of Chronic Dofetilide Overdose: A Case Report

Managing the risks and consequences of long QT syndrome can be challenging. Multiple factors contribute to the prolongation of the heart-rate corrected QT (QTc) interval including many drug-drug and drug-disease state interactions. Current literature is often focused on avoiding dysrhythmias with limited guidance on acute management strategies. Here we describe a case of QTc prolongation to 616 msec (Bazett's formula) in the setting of chronic dofetilide overdose due to a possible prescription error. Our case was complicated by alcohol withdrawal and electrolyte disturbances that progressed to patient cardiac arrest in the emergency department. Dofetilide overdose was identified through pharmacist-initiated medication reconciliation and lidocaine was recommended as an alternative to amiodarone during advanced cardiac life support (ACLS). This case highlights the importance of reviewing outpatient medication records as well as avoiding drug-drug interactions during ACLS. Due to the potential for additive QTc prolongation, we recommend using lidocaine as the preferred antiarrhythmic in ACLS algorithms where drug induced QTc prolongation is suspected.

How to Estimate QT Interval in Patients With Left or Right Bundle Branch Block: A Systematic Review

PURPOSE/BACKGROUND

Prolonged QT interval related to psychopharmacological treatment is a risk factor for potentially life-threatening arrhythmias. Electrocardiographic measurements are recommended in patients with cardiovascular risk factors before initiating treatment with potentially QT-prolonging medications, such as certain antidepressants or antipsychotics. In patients with left bundle branch block (LBBB) or right bundle branch block (RBBB), conventional QT-estimation methods will lead to overestimation of the QT interval, as the conduction defect, reflected by the QRS duration, will increase the QT interval without representing longer repolarization as in drug-induced QT prolongation.

METHODS/PROCEDURES

We conducted a systematic review of methods to estimate QT interval in the presence of LBBB or RBBB. We searched electronic databases Embase and Medline (last search, August 12, 2020).

FINDINGS/RESULTS

We found 8 different methods, including linear correction formulae with and without correction for heart rate, or simpler formula correcting QRS duration with empirically derived modifiers. Only 3 of 8 methods were applicable in the presence of RBBB, whereas all 8 methods could be applied in the presence of LBBB.

IMPLICATIONS/CONCLUSIONS

The QT interval is overestimated in patients with LBBB or RBBB, when using conventional measurements. Several alternative correction formulae exist, which can be applied using standard measurements from ordinary electrocardiographic readings. However, it is currently unknown whether or not the QT prolongation observed in the presence of bundle branch block significantly increases the risk of arrhythmias, as these formulae have not been tested against patient-specific clinical outcomes.

Drug-Associated QTc Prolongation in Geriatric Hospitalized Patients: A Cross-Sectional Study in Internal Medicine

Objective

The primary objectives of this prospective cross-sectional study were to estimate the prevalence of drug-related long QT syndrome (LQTS) and the prevalence of use of QT-prolonging drugs in older patients admitted to an internal medicine unit.

Methods

We screened consecutive patients hospitalized in an internal medicine unit over a 2-year period. A 12-lead electrocardiogram using an electrocardiograph with automated measurement of QT interval was recorded. Patient characteristics (age, sex, body mass index), drug treatments, and variables associated with QT interval prolongation, including hypothyroidism, type 2 diabetes mellitus, and cardiac disease, were also recorded. In addition, we also measured serum levels of potassium, calcium, magnesium, and creatinine at admission. The list of medications known to cause or to contribute to LQTS was obtained from CredibleMeds^®.

Results

A total of 243 patients were enrolled: mean ± standard deviation age, 79.65 ± 8.27 years; males, n = 121 (40.8%); mean corrected QT (QTc) interval, 453.70 ± 43.77 ms. Overall, 89/243 (36.6%) patients had a prolonged QTc interval, with 29/243 (11.9%) having QTc interval prolongation > 500 ms (11.9%). A vast majority were prescribed at least one QT-prolonging drug (218/243 [89.7%]), whereas 74/218 (30.5%) were receiving at least one medication with a known risk of Torsades des Pointes (TdP). Proton pump inhibitors were the second most commonly prescribed class of drugs. After logistic regression, male sex was independently associated with LQTS (odds ratio 2.85; 95% confidence interval 1.56–5.22; p = 0.001).

Conclusions

The prevalence of LQTS with QTc interval > 500 ms in geriatric inpatients was > 10%, and QT-prolonging drugs were frequently used on admission (more than 30% of patients were receiving drugs with a known risk of TdP).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00234-x.

QTc prolongation in COVID-19 patients treated with hydroxychloroquine, chloroquine, azithromycin, or lopinavir/ritonavir: A systematic review and meta-analysis

Purpose

Hydroxychloroquine, chloroquine, azithromycin, and lopinavir/ritonavir are drugs that were used for the treatment of coronavirus disease 2019 (COVID‐19) during the early pandemic period. It is well‐known that these agents can prolong the QTc interval and potentially induce Torsades de Pointes (TdP). We aim to assess the prevalence and risk of QTc prolongation and arrhythmic events in COVID‐19 patients treated with these drugs.

Methods

We searched electronic databases from inception to September 30, 2020 for studies reporting peak QTc ≥500 ms, peak QTc change ≥60 ms, peak QTc interval, peak change of QTc interval, ventricular arrhythmias, TdP, sudden cardiac death, or atrioventricular block (AVB). All meta‐analyses were conducted using a random‐effects model.

Results

Forty‐seven studies (three case series, 35 cohorts, and nine randomized controlled trials [RCTs]) involving 13 087 patients were included. The pooled prevalence of peak QTc ≥500 ms was 9% (95% confidence interval [95%CI], 3%–18%) and 8% (95%CI, 3%–14%) in patients who received hydroxychloroquine/chloroquine alone or in combination with azithromycin, respectively. Likewise, the use of hydroxychloroquine (risk ratio [RR], 2.68; 95%CI, 1.56–4.60) and hydroxychloroquine + azithromycin (RR, 3.28; 95%CI, 1.16–9.30) was associated with an increased risk of QTc prolongation compared to no treatment. Ventricular arrhythmias, TdP, sudden cardiac death, and AVB were reported in <1% of patients across treatment groups. The only two studies that reported individual data of lopinavir/ritonavir found no cases of QTc prolongation.

Conclusions

COVID‐19 patients treated with hydroxychloroquine/chloroquine with or without azithromycin had a relatively high prevalence and risk of QTc prolongation. However, the prevalence of arrhythmic events was very low, probably due to underreporting. The limited information about lopinavir/ritonavir showed that it does not prolong the QTc interval.