• Journal of Dental Anesthesia and Pain Medicine
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• 제20권3호
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• pp.165-171
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• 2020

The congenital long QT syndrome (LQTS) is an inherited cardiac disorder characterized by increased QT intervals and a tendency to experience ventricular tachycardia, which can cause fainting, heart failure, or sudden death. A 4-year-old female patient undergoing velopharyngeal correction surgery under general anesthesia suddenly developed Torsades de pointes. Although the patient spontaneously resolved to sinus rhythm without treatment, subsequent QT prolongation persisted. Here, we report a case of concealed LQTS with a literature review.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1989년도 춘계학술대회
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• pp.13-14
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• 1989

Prolongation in QT corrected interval (QTc), measured in surface ECG, has been shown in the majority af patients to be marker of bad prognosis in postmyocardial infarction patients (PMIP). Hence it would seem logical that dynamic QTc interval measurement can be a very usefull indicator to stratify prognosis in PMIP. We present a new algorithm for QT as well as for QTP (distance value from Q wave onset to T wave peak) intervals measurement in 24 hour ECG Holter tapes. Validation of the algorithm by hand measurement has been done on first beats of 18 Holter tapes, resulting in a magnitude of deviations between 10 and 15 ms. Application on 24 hour Holter ECG signal has also been done.

• Reproductive and Developmental Biology
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• 제34권3호
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• pp.153-159
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• 2010

The 34 potently pig pheromonal odorants (1-32, 5755 & 7113) through structure-based virtual screening and ligand-based virtual screening method were selected and their ADMET and pharmacokinetics characters were evaluated and discussed quantitatively. The pheromonal odorants were projected on the following pre-calculated models, Caco-2 cell permeability, blood-brain barrier permeation, hERG inhibition and volume-distribution. From the results of in silico study, it is found that an optimal compound (31) either penetrating or have a little ($P_{caco2}$=-8.143) for Caco-2 cell permeability, moderate penetrating ability ($P_{BBB}$=0.082) for blood-brain barrier permeation, the low QT prolongation ($P_{hERG}$=1.137) for the hERG $K^+$ channel inhibition, and low distribution into tissues ($P_{VD}$=-5.468) for volume-distribution. Therefore, it is predicted that the compound (31) a topical application may be preferable from these based foundings.

• Clinical and Experimental Pediatrics
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• 제58권7호
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• pp.263-266
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• 2015

Purpose: Ventricular repolarization is assessed using the QT interval corrected by the heart rate (QTc) via an electrocardiogram (ECG). Prolonged QTc is associated with an increased risk of arrhythmias and cardiac mortality. As there have been few reports regarding the effects of hyperthyroidism on ventricular repolarization, we studied the association between serum free thyroxine (free T4 [fT4]) and thyroid stimulating hormone (TSH) levels and the QTc interval. Methods: Thirty-eight patients with hyperthyroidism (<30 years old) were included, and we used their clinical records and available ECGs (between August 2003 and August 2011) to evaluate the association between their fT4 and TSH levels and their QTc interval. In addition, we studied the ECGs of 72 age-matched patients with no hyperthyroidism (control group) and compared their data with that from the patients group. Results: The QTc duration in patients with hyperthyroidism was significantly prolonged compared to that in the control subjects (P<0.001). In addition, the number of hyperthyroid patients with abnormal prolonged QTc was significantly higher than that in the control group (P<0.001). Among the patients with hyperthyroidism, patients with prolonged QTc and borderline QTc had higher fT4 levels and there was positive correlation between their fT4 levels and their QTc interval (P<0.05). However, no correlation was observed between their TSH levels and their QTc interval. Conclusion: We report that hyperthyroidism is associated with QTc prolongation. The correlation between the fT4 levels and the QTc interval suggests that thyroid status is associated with QTc values and the risk of cardiac mortality.

• Journal of Dental Anesthesia and Pain Medicine
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• 제15권3호
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• pp.161-165
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• 2015

Long QT syndrome (LQTs) is a rare congenital disorder of the heart's electrical activity. Patients with LQTs are at increased risk of developing fatal ventricular arrhythmias. Elevated levels of sympathetic stimulation can exacerbate this risk. Successful behavior management is indispensable in the treatment of patients with LQTs. However, many drugs involved in pharmacologic behavior management are known to adversely affect the QT interval. Therefore, careful selection of a sedative drug is essential in avoiding such incidences. A 10-year-old boy with a known diagnosis of LQTs required restorative treatment due to dental caries at the permanent molar. He required sedation since treatment was painful and dental phobia can trigger sympathetic stimulation, creating a dangerous situation for patients with LQTs. Therefore, the treatment was performed over two sessions under moderate sedation involving propofol combined with nitrous oxide. Restorative treatment was successful without any complications under sedation with a target-controlled infusion (TCI) of propofol. There was no significant QT prolongation during pulpal treatment. Propofol TCI may be a good candidate for sedation in patients with LQTs.

• 대한임상약리학회:학술대회논문집
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• 대한임상약리학회 1999년도 제8차 추계학술대회 및 정기총회
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• pp.52-52
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• 1999

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.64-64
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• 1999

Amitriptyline has been known to induce QT prolongation and ventricular arrhythmias such as torsades de pointes which causes sudden death. We studied the effects of amitriptyline on the human ether-a-go-go-related gene (HERG) channel expressed in Xenopus oocytes.(omitted)

• 약학회지
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• 제50권2호
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• pp.129-135
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• 2006

Two Antihistamines, terfenadine and astemizole have been withdrawn from major markets for the reason that these durgs have been reported to induce QT interval prolongation associated with the onset of Torsades do Pointes (TdP), resulting in a life-threatening ventricular arrhythmia. In this study, we investigated effects of diphenhydramine on electrocardiograms and hemodynamic parameters in conscious telemetered dogs. We validated and defined the sensitivity of the test system by monitoring basal parameters and using positive control substance, terfenadine. Single administration effects were tested during 24 hours for each test drug at dose 1 mg/kg, 10 mg/kg, 30 mg/kg, 100 mg/kg. We monitored QT, QTc, heart rate, blood pressure and body temperature after administering test drugs. In conscious telemetered dogs, diphenhydramine significantly prolonged $QT\;(6.8\%\;of\;basal)\;and\;QTc\;(7.8\%\;of\;basal)$ at 100 mg/kg. Other parameters were not affected significantly. These findings suggest that antihistamines could induce important clinical relevance for patients taking excessive dosages of conventional antihistamines and those at risk of developing cardiac arrhythmias. Future studies that include other antihistamines and other classes will be necessary to predict the torsadogenic risk of drugs in humans.

• Toxicological Research
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• 제22권2호
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• pp.109-116
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• 2006

Safety pharmacology studies are conducted to investigated the potential undesirable pharmacodynamic effects of a substance on physiological functions in relation to exposure in the therapeutic range and above. In the International Conference on Harmonisation (ICH), the guideline 'S7A: Safety Pharmacology Studies for Human Pharmaceuticals' has been developed and reached Step 5 of the ICH process in 2001. Now the Korea Food and Drug Administration (KFDA) are going to transfer 'The Guideline for General Pharmacology' into 'The Guideline for Safety Pharmacology'. Safety pharmacology studies should be performed in compliance with Good Laboratory Practice (GLP). Thus, the present paper reviews the Japanese GLP guidelines for pharmaceuticals to help the conduct and inspection of safety pharmacology studies in compliance with GLP. We also reviewed the ICH guidelines 'S7B revised : The Nonclinical Evaluation of the Potential for Delayed Ventricular Repolarization (QT Interval Prolongation) by Human Pharmaceuticals' and 'E14 : The Clinical Evaluation of QT/QTc Interval Prolongation and Proarrhythmic Potential for Non-antiarrhythmic Drugs' to apply our drug approval systems.

• 한국임상약학회지
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• 제33권4호
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• pp.242-253
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• 2023

Background: Arrhythmia due to QT prolongation is one of the most serious adverse events with drug interactions in the elderly. This study aimed to examine the incidence of arrhythmia in Korean elderly patients who administered both cytochrome P450 3A4 (CYP3A4) substrates and inhibitors. Methods: Patients using CYP3A4 substrate and inhibitor were selected from the 2017 elderly patient dataset (the Korean Health Insurance Review and Assessment Service - Aged Population Sample). Selection criteria were patients with a medication possession ratio over 80%, medication duration of at least 7 days, and a follow-up period of 3 months or more. The patient's basic information is age, gender, health insurance type, and comorbidities. The top 50 drug pairs and comorbidity with high-incidence arrhythmia were presented. Results: In patients with drug combinations for over 7 days, there were 981 incidences of arrhythmia, and 351 incidences in those with combinations for over 30 days. The comorbidities of congestive heart failure and myocardial infarction had a significant association with incidence of arrhythmia. Among patients with 7 days or longer, the drug pairs [substrates-inhibitors] with significant adjusted odds ratio (aOR) were [propranolol-cimetidine] (aOR, 2.25; 95% confidence interval [CI], 1.66-3.04). Among patients with 30 days or longer, the drug pairs with significant aOR were [tramadol-amiodarone] (aOR, 2.87; 95% CI, 1.97-4.19). Conclusions: In elderly patients, the incidence of arrhythmia was high with drug interactions of CYP3A4 substrates and inhibitors. The comorbidity of congestive heart failure was the risk factor.