QTc-prolonging drugs and the risk of sudden death

Various drugs can be associated with QT prolongation. A prolonged QT interval leads to an increased risk for the development of ventricular tachyarrhythmias, particularly polymorphic ventricular tachycardia (torsades de pointes). Polymorphic arrhythmia may rapidly develop into ventricular fibrillation and cause sudden death. Torsades de pointes is classically associated with early depolarization. This review article discusses the mechanisms of QTc prolongation and triggering factors for proarrhythmia, drugs that prolong QT interval (class III antiarrhythmic agents, antimicrobial agents – fluoroquinolone and macrolide antibiotics, antipsychotic and antidepressant drugs, agents used in general anesthesia, antimycotics, and several other drugs), nonpharmacological and pharmacological risk factors for arrhythmias (due to pharmacokineticpharmacodynamic interactions), the treatment and recommendations to prevent arrhythmia related to QT prolongation.

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The QT long syndrome: clinical and diagnostic aspect

Bulletin of the Academy of Sciences of Moldova. Medical Sciences ◽

10.52692/1857-0011.2021.1-69.29 ◽

2021 ◽

Vol 69 (1) ◽

Author(s):

Constantin Martiniuc ◽

◽

Serghei Pisarenco ◽

Iurie Simionica ◽

◽

...

Keyword(s):

Qt Interval ◽

Torsade De Pointes ◽

Qt Prolongation ◽

Current Data ◽

Polymorphic Ventricular Tachycardia ◽

Interval Prolongation ◽

Qt Interval Prolongation ◽

Increased Risk ◽

Wide Range ◽

Life Threatening

QT interval prolongation is a predictor of the life-threatening cardiac arrhythmias — polymorphic ventricular tachycardia (torsade de pointes). Long QT syndrome may be congenital or acquired. It is known that a wide range of both antiarrhythmic and non-cardiac medications might lead to QT interval prolongation. List of drugs that cause QT prolongation is constantly growing and being updated. The review contains current data on the clinical significance of the control of QT interval duration within drug therapy. Clinical conditions associated with an increased risk of QT interval prolongation are described. Drugs that can induce QT prolongation are also discussed.

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Cardiac Arrest Related to Torsades de Pointes in a Patient Recovering from Diabetic Ketoacidosis

Korean Journal of Medicine ◽

10.3904/kjm.2021.96.5.432 ◽

2021 ◽

Vol 96 (5) ◽

pp. 432-437

Author(s):

Jinmo Kim ◽

Ju Yeop Lee ◽

Won Sang Yoo ◽

Myung Yong Lee ◽

Hyun-Kyung Chung

Keyword(s):

Diabetic Ketoacidosis ◽

Qt Interval ◽

Clinical Course ◽

Structural Heart Disease ◽

Torsades De Pointes ◽

Recovery Phase ◽

Qt Prolongation ◽

Polymorphic Ventricular Tachycardia ◽

Appropriate Therapy ◽

Prolonged Qt Interval

Diabetic ketoacidosis (DKA) is an acute complication related to severe hyperglycemia. While the mortality rate for DKA is low with appropriate therapy, several complications may lead to deterioration of the clinical course. Here, we report a case of a 23-year-old patient with DKA who suffered from a rare but hemodynamically unstable cardiac arrhythmia, polymorphic ventricular tachycardia with prolonged QT interval, or Torsades de Pointes. During the recovery phase of DKA, three episodes of Torsades de Pointes suddenly occurred, and were recovered by immediate defibrillation. The patient did not have structural heart disease or a genetic predisposition. To the best of our knowledge, this is the first report of an adult with DKA complicated with QT prolongation related to Torsades de Points after correction of ketosis. To manage DKA, more attention may be needed on changes in the QT interval as well as risk factors for Torsades de Points.

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Fluconazole-associated QT interval prolongation and Torsades de Pointes in a paediatric patient

Cardiology in the Young ◽

10.1017/s1047951121001992 ◽

2021 ◽

pp. 1-3

Author(s):

Ayşe Ünal Yüksekgönül ◽

İlker Ertuğrul ◽

Tevfik Karagöz

Keyword(s):

Qt Interval ◽

Torsades De Pointes ◽

Qt Prolongation ◽

Polymorphic Ventricular Tachycardia ◽

Interval Prolongation ◽

Qt Interval Prolongation ◽

Life Threatening ◽

Prolonged Qt Interval ◽

Rhythm Disorder ◽

Anti Fungal

Abstract “Torsades de pointes”, a life-threatening rhythm disorder, is a polymorphic ventricular tachycardia that usually develops in association with a prolonged QT interval. Fluconazole, an anti-fungal drug, may also induce QT prolongation, in some cases subsequent torsades de pointes. Herein, we report a 16-year-old female presenting “torsades de pointes” after administration of fluconazole and rapidly improved upon cessation of the drug.

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Qtc Prolongation as Prognostic Marker in Organophosphate Poisoning

International Journal Of Medical Science And Clinical Invention ◽

10.18535/ijmsci/v8i04.01 ◽

2021 ◽

Vol 8 (04) ◽

pp. 5317-5337

Author(s):

Dr. Digbijay Kumar Thakur ◽

Dr. Dhruba Gaire ◽

Dr. Siddi Datri Jha ◽

Dr. Rameshwar Mahaseth

Keyword(s):

Ventricular Tachycardia ◽

Qt Interval ◽

Torsades De Pointes ◽

Polymorphic Ventricular Tachycardia ◽

K Channel ◽

Organophosphate Poisoning ◽

Ca Channel ◽

Corrected Qt Interval ◽

Normal Limits ◽

Increased Risk

Background The long QT syndrome (LQTS) is a disorder of myocardial repolarization characterized by a prolonged QT interval on the electrocardiogram (ECG). This syndrome is associated with an increased risk of polymorphic ventricular tachycardia, a characteristic life-threatening cardiac arrhythmia also known as torsades de pointes. A rate related corrected QT interval (QTc) can be calculated as QT/√RR and normally is ≤0.44s. Some references given QTc upper normal limits as 0.43s in men and 0.45s in female. OP compound supposed to block K+ channel and Na+/Ca++ channel and hence causing prolongation of QT interval. As we know that prolongation of QT interval may precipitate polymorphic ventricular tachycardia and sudden cardiac death, so it become important in case of OP poisoning and related mortality. In this study, I calculated corrected QT interval in diagnosed cases of OP poisoning admitted at Bir Hospital and compared QTc among those with complications and without complication. I also tried to evaluate QTc as a predictor for duration of hospital stays, ICU admission, vasopressor and mechanical ventilation requirement, higher POP score and low GCS.

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QTU-Prolongation and Torsades de Pointes Induced by Putative Class III Antiarrhythmic Agents in the Rabbit

Journal of Cardiovascular Pharmacology ◽

10.1097/00005344-199008000-00014 ◽

1990 ◽

Vol 16 (2) ◽

pp. 276-285 ◽

Cited By ~ 183

Author(s):

Leif Carlsson ◽

Olle Almgren ◽

Goran Duker

Keyword(s):

Torsades De Pointes ◽

Antiarrhythmic Agents ◽

Class Iii

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Abstract 14311: Qt Interval Correlation Between Telemetry and 12-lead Electrocardiogram

Circulation ◽

10.1161/circ.142.suppl_3.14311 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Mohamed Farhan Nasser ◽

Ahmad Jabri ◽

Saima Karim ◽

Elizabeth Kaufman

Keyword(s):

Qt Interval ◽

Ventricular Arrhythmias ◽

Qt Prolongation ◽

T Wave ◽

Qt Intervals ◽

Increased Risk ◽

Tangent Method ◽

Wave Morphology ◽

Monitoring Service ◽

Inpatient Units

Introduction: QT prolongation is associated with increased risk of ventricular arrhythmias.As many patients with COVID19 may be started on QT prolonging drugs, measuring and monitoring QT is imperative to prevent fatal ventricular arrhythmias. However, we need to limit exposure of staff to patients with confirmed COVID19 and judiciously use personal protective equipment. Thus, it is important to find alternatives to doing frequent 12-lead ECGs. Hypothesis: We hypothesize that the QT interval measured from telemetry is similar to the QT interval on 12-lead ECG. Methods: Telemetry recordings and 12-lead ECGs were obtained from 15 patients at the same time and identical heart rates. Patients were from two different inpatient units with the same telemetry monitoring service. QT intervals were measured manually using calipers with the tangent method, excluding U waves. Telemetry recordings included lead I and II or a precordial lead. QT from telemetry was compared to the corresponding leads and to the longest QT on the 12-lead ECG. In cases of atrial fibrillation (AF), the QT from all the complexes was averaged. Results: Of 15 patients, 2 were in AF and 2 had RBBB. One patient had abnormal T-wave morphology and QT prolongation (abnormal repolarization). In all patients, QT intervals from the same leads as telemetry matched the QT measured from 12-lead. In 14 of 15 patients, telemetry QT matched the longest QT on the 12-lead ECG. However, in the patient with abnormal repolarization, maximum QT on 12-lead ECG was substantially longer than telemetry QT (Figure 1). Conclusion: When using the same lead, QT intervals were identical on telemetry and 12-lead ECG. However, in the patient with abnormal repolarization, the longest QT on 12-lead ECG was not represented on telemetry. In patients with abnormal repolarization on 12-lead ECG, we recommend serial 12-lead ECGs while on QT-prolonging drugs. Telemetry may suffice as a surrogate for 12-lead ECG to follow QT intervals in most patients.

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Abstract 13215: Gender-affirming Hormones Are Associated With Increased Risk of QT Prolongation in Transgender Females

Circulation ◽

10.1161/circ.142.suppl_3.13215 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Daniel Antwi Amoabeng ◽

Ahmed Hanfy ◽

Munadel Awad ◽

Bryce D Beutler ◽

Amneet Rai ◽

...

Keyword(s):

Qt Interval ◽

Small Sample Size ◽

Qt Prolongation ◽

Small Sample ◽

Rank Test ◽

Qt Interval Prolongation ◽

Northern Nevada ◽

Increased Risk ◽

Before And After ◽

Signed Rank Test

Introduction: Women have a longer QT interval than men. This sex-specific difference is attributed to hormones associated with the biological female sex. Male-to-female transgender individuals often take antiandrogens such as spironolactone or goserelin in addition to estrogens to suppress testosterone effects while increasing feminine features. Effects of gender-affirming hormone therapy (GHT) on the QT interval in these individuals remains to be elucidated. Hypothesis: We assessed the hypothesis that the use of GHT is associated with an increased risk for QT interval prolongation in transgender females. Methods: We identified 46 transgender females through a search of the electronic medical records of a Veterans Administration hospital in Northern Nevada. Patients with a diagnosis of congenital long QT syndrome were excluded. Of these, 13 patients had ECGs before and after initiation of GHT and were included. We adapted the Tisdale score using the auto-calculated corrected QT interval (QTc) to estimate the risk of QT prolongation. Age, QTc, and Tisdale scores before and after GHT initiation were compared using the Wilcoxon signed-rank test. All tests were performed as two-tailed at a 5% level of significance. Results: All 13 study patients were taking estrogens. Of these, 3 (23.1%) were taking goserelin and 9 (69.2%) were taking spironolactone. Mean ± SEM age at ECG acquisition was 45.0 ± 4.4 and 47.7 ± 4.7 years before and after the initiation of GHT respectively. Mean ± SEM QTc after initiation of GHT was significantly higher compared to the baseline (467.5 ± 12.8 ms vs. 428.2 ± 7.1 ms) (Figure 1A). The average baseline Tisdale score was significantly smaller on follow-up (1-point vs. 3 points) (Figure 1B). Conclusions: GHT appears to be associated with increased QTc in transgender women. This needs to be interpreted with caution owing to the very small sample size in this study. Further studies to investigate the strength of this association, if it exists, are warranted.

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Managing drug-induced QT prolongation in clinical practice

Postgraduate Medical Journal ◽

10.1136/postgradmedj-2020-138661 ◽

2020 ◽

pp. postgradmedj-2020-138661

Author(s):

Rani Khatib ◽

Fatima R N Sabir ◽

Caroline Omari ◽

Chris Pepper ◽

Muzahir Hassan Tayebjee

Keyword(s):

Qt Interval ◽

Simple Algorithm ◽

Torsades De Pointes ◽

Daily Practice ◽

Qt Prolongation ◽

Key Factors ◽

Drug Induced ◽

Electrolyte Disturbances ◽

Related Risk ◽

Life Threatening

Many drug therapies are associated with prolongation of the QT interval. This may increase the risk of Torsades de Pointes (TdP), a potentially life-threatening cardiac arrhythmia. As the QT interval varies with a change in heart rate, various formulae can adjust for this, producing a ‘corrected QT’ (QTc) value. Normal QTc intervals are typically <450 ms for men and <460 ms for women. For every 10 ms increase, there is a ~5% increase in the risk of arrhythmic events. When prescribing drugs associated with QT prolongation, three key factors should be considered: patient-related risk factors (eg, female sex, age >65 years, uncorrected electrolyte disturbances); the potential risk and degree of QT prolongation associated with the proposed drug; and co-prescribed medicines that could increase the risk of QT prolongation. To support clinicians, who are likely to prescribe such medicines in their daily practice, we developed a simple algorithm to help guide clinical management in patients who are at risk of QT prolongation/TdP, those exposed to QT-prolonging medication or have QT prolongation.

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