Measurement of the QT interval and the risk associated with QTc interval prolongation: A review

1993 ◽  
Vol 72 (6) ◽  
pp. B23-B25 ◽  
Author(s):  
Arthur J. Moss
Keyword(s):  
Qt Interval ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Qtc Interval Prolongation

scholarly journals Absence of relevant QT interval prolongation in not critically ill COVID-19 patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan Jiménez-Jáimez ◽  
Rosa Macías-Ruiz ◽  
Francisco Bermúdez-Jiménez ◽  
Ricardo Rubini-Costa ◽  
Jessica Ramírez-Taboada ◽  
...  
Keyword(s):  
Critically Ill ◽  
Qt Interval ◽  
Treatment Initiation ◽  
Qtc Interval ◽  
Risk Markers ◽  
Interval Prolongation ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation ◽  
Ambulatory Patients ◽  
Reported Data

AbstractSARS-CoV-2 is a rapidly evolving pandemic causing great morbimortality. Medical therapy with hydroxicloroquine, azitromycin and protease inhibitors is being empirically used, with reported data of QTc interval prolongation. Our aim is to assess QT interval behaviour in a not critically ill and not monitored cohort of patients. We evaluated admitted and ambulatory patients with COVID-19 patients with 12 lead electrocardiogram at 48 h after treatment initiation. Other clinical and analytical variables were collected. Statistical analysis was performed to assess the magnitude of the QT interval prolongation under treatment and to identify clinical, analytical and electrocardiographic risk markers of QT prolongation independent predictors. We included 219 patients (mean age of 63.6 ± 17.4 years, 48.9% were women and 16.4% were outpatients. The median baseline QTc was 416 ms (IQR 404–433), and after treatment QTc was prolonged to 423 ms (405–438) (P < 0.001), with an average increase of 1.8%. Most of the patients presented a normal QTc under treatment, with only 31 cases (14.1%) showing a QTc interval > 460 ms, and just one case with QTc > 500 ms. Advanced age, longer QTc basal at the basal ECG and lower potassium levels were independent predictors of QTc interval prolongation. Ambulatory and not critically ill patients with COVID-19 treated with hydroxychloroquine, azithromycin and/or antiretrovirals develop a significant, but not relevant, QT interval prolongation.

scholarly journals Corrected QT interval prolongation during anesthetic induction for laryngeal mask airway insertion with or without cisatracurium

2018 ◽  
Vol 46 (5) ◽  
pp. 1990-2000 ◽  
Author(s):  
Chengluan Xuan ◽  
Nan Wu ◽  
Yanhui Li ◽  
Xiaoting Sun ◽  
Qunshu Zhang ◽  
...  
Keyword(s):  
Laryngeal Mask Airway ◽  
Operating Room ◽  
Qt Interval ◽  
Laryngeal Mask ◽  
Laryngeal Mask Airway Insertion ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Anesthetic Induction ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation

Objective This study was performed to observe the occurrence of corrected QT (QTc) interval prolongation during anesthetic induction for laryngeal mask airway insertion and the effects of cisatracurium administration on the QTc interval. Methods Eighty-eight patients were assigned to two groups: the cisatracurium administration group (n = 45) and non-cisatracurium administration group (n = 43). The QTc interval was continuously recorded by a 12-lead Holter electrocardiogram beginning in the hospital ward and continuing until after anesthetic induction. Results In the cisatracurium administration group, the QTc interval significantly increased from 417.9 ± 27.9 to 451.6 ± 32.5 ms after arrival in the operating room and significantly decreased to 432.4 ± 32.5 ms after a 15-minute rest; it significantly increased to 459.7 ± 23.8 ms again after propofol and fentanyl injection. However, the QTc interval decreased after cisatracurium injection. In the non-cisatracurium administration group, the QTc interval initially showed changes similar to those in the cisatracurium group until fentanyl and propofol were injected. Conclusions The QTc interval was significantly prolonged on arrival in the operating room and after propofol and fentanyl injection. The QTc interval did not significantly change by laryngeal mask airway insertion regardless of the administration of cisatracurium.

scholarly journals Monitoring of QTc interval in patients with COVID-19. First experience with a portable EKG-recording device

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
M Abellas Sequeiros ◽  
C Lozano Granero ◽  
C Garcia Sebastian ◽  
E Franco Diez ◽  
A Hernandez Madrid ◽  
...  
Keyword(s):  
Qt Interval ◽  
Intraclass Correlation ◽  
Early Discharge ◽  
Recording Device ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Daily Monitoring ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation ◽  
Group 2

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Off-label use of drugs with potential for QT interval prolongation was common in COVID-19 patients. We tested a portable EKG recording device to measure and monitor corrected QT (QTc) intervals in a cohort of COVID-19 patients treated with azithromycin, hydroxychloroquine, lopinavir/ritonavir, or combinations of these drugs. Methods and results Sixty-nine patients hospitalized with pneumonia and confirmed SARS-CoV 2 infection were included in an observational single-centre study. Six-lead EKG recordings were obtained using a KardiaMobile6L® at physicians’ discretion. In a subgroup of 16 patients with early discharge, a device was provided for at-home daily monitoring. Significant QTc interval prolongation was observed in patients taking a combination of 2 or 3 drugs (426 ± 33 vs 408 ± 33 ms, p = 0,002; and 435 ± 30 vs 394 ± 31 ms, p = 0,001, respectively). The use of the device prompted a change in the treatment of 9 patients (13%) because of prolongation of QTc interval and anticoagulation was started in one patient because of atrial fibrillation diagnosis. In the subgroup of patients with daily recording, QTc interval prolongation peaked at day 2 ± 1,8, with a shorter final QT interval than that recorded before drug initiation (350,0 ± 31,4 vs 381,0 ± 21,2; p = 0,019), pointing to a possible role of the disease itself in QT interval modification. To assess the consistency of measurements of QTc interval, a random sample of 120 EKG recordings were analyzed by two different physicians. Inter-operator intraclass correlation coefficient was 0,702, 95% CI (0,578-0,789). Conclusions Portable EKG-recording device was useful for QTc interval monitoring in COVID-19 patients receiving drugs with QTc prolonging potential, allowing physicians to adapt management. Significant QT prolongation was observed in these patients. Characteristics of the three groups.Group 1(one drug)N= 9 (13,0%)Group 2(two drugs)N= 37 (53,6%)Group 3(three drugs)N= 23 (33,3%)p-valueClinical characteristicsAge (years)55,0 ± 18,366,0 ± 16,258,0 ± 15,8p = 0,248Male sex (%)6 (66,7%)25 (67,6%)18 (78,3%)p = 0,643Dislipidaemia (%)5 (55,6%)9 (24,3%)7 (30,4%)p = 0,749Diabetes (%)7 (77,8%)4 (10,8%)5 (21,7%)p = 0,525Hypertension (%)3 (33,3%)16 (43,2%)8 (34,8%)p = 0,387Previous cardiopathy (%)6 (66,7%)11 (29,7%)3 (13,0%)p = 0,305COPD (%)7 (77,8%)6 (16,2%)1 (8,7%)p = 0,679COPDchronic obstructive pulmonary disease.Abstract Figure. Baseline and maximum QTc intervals

scholarly journals Relationship between Corrected QT Interval (QTc) Prolongation and Insulin Resistance in Obese Adult Male Subjects

2021 ◽  
Vol 3 (1) ◽  
pp. 42-45
Author(s):  
Zarchi Theint Theint Hlaing ◽  
Soe Minn Htway ◽  
Mya Thanda Sein
Keyword(s):  
Insulin Resistance ◽  
Adult Male ◽  
Qt Interval ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Corrected Qt Interval ◽  
Qtc Interval Prolongation ◽  
Resistance State ◽  
Obese Subjects ◽  
Male Subjects

QT Interval prolongation is common in insulin resistance state obesity. Insulin-induced hyperpolarization might be involved in ventricular repolarization leading to QTc lengthening. Therefore, this study is designated to investigate the relationship between corrected QT interval (QTc) prolongation and insulin resistance in obese adult male subjects. Apparently healthy adult male subjects (n=100) aged between 18-35 years residing in Magway Township were recruited by simple random sampling method. Then all the eligible subjects were categorized into 2 groups: non-obese [body mass index (BMI) 18.5 to 24.9 kg/m2, n= 40] and obese group [BMI ≥ 30.0 kg/m2, n=60] by their anthropometric parameters. Serum fasting glucose was measured by glucose oxidase method. Serum insulin level was determined by Enzyme-Linked Immunosorbent Assay (ELISA). Insulin sensitivity was calculated by Homeostatic Model Assessment (HOMA-IR). The QT interval was measured by routine 12-lead ECG and corrected QT interval (QTc) was calculated according to Bazett’s formula. In the present study, insulin sensitivity (HOMA-IR) was higher in obese subjects (4.64±2.3) than that of non-obese subjects (2.5±0.89) (p< 0.001). There was significant positive correlation between QTc and HOMA-IR (r = 0.41, p< 0.001, n = 100) in this study. HOMA-IR >3.8 was considered as insulin resistance (IR) and QTc > 440ms was regarded as QTc interval prolongation. Insulin resistance was significantly associated with prolonged QTc interval in the study population (X2=7.3, p< 0.05, n=100). Risk of QTc interval prolongation was 3.4 times higher in subjects with IR (Odd ratio = 3.4; 95% confidence interval = 1.37 to 8.45). It was concluded that prolonged QTc interval is associated with insulin resistance state.

scholarly journals Ciprofloxacin does not Prolong the QTc Interval: A Clinical Study in ICU Patients and Review of the Literature

2017 ◽  
Vol 20 (1) ◽  
pp. 360 ◽  
Author(s):  
Charlotte Heemskerk ◽  
Evelien Woldman ◽  
Marieke Pereboom ◽  
Ruud Van der Hoeven ◽  
Aukje Mantel-Teeuwisse ◽  
...  
Keyword(s):  
Qt Interval ◽  
Torsade De Pointes ◽  
Qtc Interval ◽  
Test Results ◽  
Interval Prolongation ◽  
Icu Patients ◽  
Increased Risk ◽  
Qtc Interval Prolongation ◽  
Student’S T ◽  
Student’S T Test

Purpose. Ciprofloxacin may prolong the QT interval and increase the risk of Torsade de Pointes (TdP). Intravenous administration of ciprofloxacin in patients with additional risks may elevate the risk of QTc interval prolongation. We prospectively assessed whether intravenous ciprofloxacin prolongs the QT interval in patients with additional co-morbidities and risk factors. We also reviewed the literature on the QT prolonging effect or TdP inducing effect of ciprofloxacin. Methods. ICU Patients who were treated with intravenous ciprofloxacin as part of their therapy were recruited. ECG was recorded within 60 min before start and in the last 30 min of 1 h infusion, or within 30 min after the end of ciprofloxacin infusion. QT interval was corrected for the heart rate using both Bazett’s and Fridericia’s formula. The changes were analyzed using the paired Student’s t-test. Results. Ten patients were included in the study (average age 74-y, 6 males). The average baseline QTc interval corrected with Bazett’s formula was 448 ms that was shortened during or after ciprofloxacin infusion by 3 ms and 2 ms based on Bazett’s  (p=0.67) and Fridericia’s (p=0.68) formula, respectively. No observational study  or cohort study thus far has shown that ciprofloxacin has a QT prolonging effect or increases the risk of TdP or (cardiovascular) mortality.  Conclusion. Based on our results and the results of previous studies, it is unlikely that ciprofloxacin has a clinically relevant QT prolonging effect or an increased risk of TdP. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

SSRIs and QT interval prolongation management. A review

2017 ◽  
Vol 41 (S1) ◽  
pp. S750-S750
Author(s):  
A. Ballesteros ◽  
H. Saiz ◽  
Á.S. Rosero ◽  
A. Portilla ◽  
L. Montes ◽  
...  
Keyword(s):  
Risk Factors ◽  
Qt Interval ◽  
Future Research ◽  
Current Debate ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Drug Induced ◽  
Cross Sectional ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation

IntroductionIn 2011, the FDA issued an alert recommending not to prescribe citalopram high doses, due to QT prolongation risk. We explored the clinical background of QT interval prolongation related to serotonin selective reuptake inhibitors (SSRI) use and the clinical implications of safety issues.MethodologyA review was conducted to clarify the mechanisms associated with the occurrence of TdP when using SSRI and investigating therapeutic measures to avoid/minimize these effects. The literature search was conducted in PubMed data reviewing articles between 2001 and 2016.Results(1) Related to risk factors/intraclass differences: risk factors are increase in QTc interval ≥60 ms from the pretreatment value, advanced age, female sex, acute myocardial infarction and electrolytic abnormalities among others. Citalopram appears more likely than others to induce this phenomenon but its importance is under current debate. (2) Related to dose: drug-induced QTc interval prolongation and TdP was associated to citalopram in doses > 40 mg/day. However, psychotropic drug-induced sudden cardiac death may be an outlier in the absence of identified risk factors for QTc interval prolongation and TdP. (3) Related to poly-pharmacy/management: there is an additive effect when using SSRI and antipsychotics (EKG control is recommended in those cases). Cross-sectional studies showed that SSRI use was not associated with QT interval prolongation. This could be explained by the EKG intra-intersubject variability.ConclusionsThere is little evidence that drug-associated QTc interval prolongation by itself is sufficient to predict TdP. Future research needs to improve its precision to better understand the factors that facilitate/attenuate that progression. Clarifying this may lead to a safer SSRI use.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals QT Interval Prolongation in Patients with Systemic Sclerosis—Are the Holter ECG Recordings a Better Option for QT Interval Evaluation?

Medicina ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 295
Author(s):  
Elena E. Saramet ◽  
Doina-Clementina Cojocaru ◽  
Sorin Ungurianu ◽  
Robert D. Negru ◽  
Codrina Ancuta
Keyword(s):  
Systemic Sclerosis ◽  
Qt Interval ◽  
Qtc Interval ◽  
Ecg Monitoring ◽  
Interval Prolongation ◽  
Holter Ecg ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation ◽  
Interval Evaluation ◽  
Myocardial Involvement

Background and Objectives: Cardiac involvement in systemic sclerosis has important consequences on patient survival. Myocardial fibrosis and microcirculation involvement can generate arrhythmic complications, which can be associated with a higher death risk. QT interval prolongation is considered as a risk factor for ectopic ventricular events and can be evaluated using standard short ECG recordings or 24-h Holter ECG recordings. Materials and Methods: 39 patients with systemic sclerosis were submitted to a standard ECG recording at admission and 24-h Holter ECG monitoring. Results: QT interval values resulted from Holter ECG monitoring are higher than the values generated by the short-term ECG recordings. Holter ECG monitoring permits the detection of ventricular ectopy in patients with no events on standard ECG. Conclusions: In patients with systemic sclerosis, 24-h Holter ECG recordings can realize a more precise evaluation of the extent of QTc interval prolongation and ventricular ectopic events associated with myocardial involvement.

QTc Prolongation Associated with Combination Therapy of Levofloxacin, Imipramine, and Fluoxetine

2005 ◽  
Vol 39 (3) ◽  
pp. 543-546 ◽  
Author(s):  
Diane L Nykamp ◽  
Casey L Blackmon ◽  
Paul E Schmidt ◽  
Andrea G Roberson
Keyword(s):  
Combination Therapy ◽  
Qt Interval ◽  
Case Reports ◽  
Plasma Concentrations ◽  
Care Physician ◽  
White Female ◽  
Qtc Interval ◽  
Interval Prolongation ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation

OBJECTIVE: To report QTc interval prolongation associated with combination therapy including levofloxacin, imipramine, and fluoxetine. CASE SUMMARY: A 49-year-old white female presented to the emergency department with fever, aches, and pains for the past 3 days. She was diagnosed and treated for pyelonephritis in the hospital. Therapy included intravenous levofloxacin 500 mg every 24 hours and ceftriaxone 2 g every 24 hours, along with her medications upon admission, including imipramine 50 mg at bedtime and fluoxetine 10 mg/day. She was discharged after 5 days and returned the next day with chest tightness and shortness of breath. Upon the second admission, a 12-lead electrocardiogram showed a QTc interval of 509 msec. Levofloxacin was discontinued and the QTc interval fell to 403 msec. The patient was discharged 3 days later and instructed to consult with her primary care physician about discontinuing imipramine. DISCUSSION: This adverse drug reaction is thought to be a pharmacodynamic additive effect among fluoxetine, imipramine, and levofloxacin. Fluoxetine is a potent inhibitor of CYP2D6, and imipramine is metabolized by CYP2D6. Therefore, fluoxetine is able to increase the plasma concentrations of imipramine, leading to QT interval prolongation. Taken with imipramine, levofloxacin can lead to even greater prolongation of the QT interval. Based on the Naranjo probability scale, levofloxacin was possibly associated with cardiac arrhythmias in our patient. CONCLUSIONS: The use of levofloxacin alone, or more often in concomitant therapy with other medications that are known to prolong the QT interval, may cause QT interval prolongation; however, additional studies/case reports are needed to validate this conclusion.

scholarly journals Absence of relevant QT interval prolongation in not critically ill COVID-19 patients.

2020 ◽  
Author(s):  
Juan J Jaimez ◽  
Rosa Macias ◽  
Francisco Bermudez ◽  
Ricardo Rubini ◽  
Miguel Alvarez ◽  
...  
Keyword(s):  
Critically Ill ◽  
Qt Interval ◽  
Treatment Initiation ◽  
Qtc Interval ◽  
Risk Markers ◽  
Interval Prolongation ◽  
Qt Interval Prolongation ◽  
Qtc Interval Prolongation ◽  
Ambulatory Patients ◽  
Reported Data

Objectives. SARS-CoV-2 is a rapidly evolving pandemic causing great morbimortality. Medical therapy with hydroxicloroquine, azitromycin and protease inhibitors is being empirically used, with reported data of QTc interval prolongation. Our aim is to assess QT interval behaviour in a not critically ill and not monitored cohort of patients. Design. We evaluated admitted and ambulatory patients with COVID-19 patients with 12 lead electrocardiogram at 48 hours after treatment initiation. Other clinical and analytical variables were collected. Statistical analysis was performed to assess the magnitude of the QT interval prolongation under treatment and to identify clinical, analytical and electrocardiographic risk markers of QT prolongation independent predictors. Results. We included 219 patients (mean age of 63.6 +/- 17.4 years, 48.9% were women and 16.4% were outpatients. The median baseline QTc was 416 ms (IQR 404-433), and after treatment QTc was prolonged to 423 ms (405-438) (P < 0.001), with an average increase of 1.8%. Most of the patients presented a normal QTc under treatment, with only 31 cases (14,1 %) showing a QTc interval > 460 ms, and just one case with QTc > 500 ms. Advanced age, longer QTc basal at the basal ECG and lower potassium levels were independent predictors of QTc interval prolongation. Conclusions. Ambulatory and not critically ill patients with COVID-19 treated with hydroxychloroquine, azithromycin and/or antiretrovirals develop a significant, but not relevant, QT interval prolongation.

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