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Acid-Base, Electrolyte And Renal Emergencies
Published in Anthony FT Brown, Michael D Cadogan, Emergency Medicine, 2020
Anthony FT Brown, Michael D Cadogan
Gain i.v. access and attach an ECG monitor. Non-specific ECG changes include: Flat or inverted T waves, prominent U waves.Prolonged PR interval.ST segment depression.Ventricular arrhythmias, including torsades de pointes.
Cardiology
Published in Rachel U Sidwell, Mike A Thomson, Concise Paediatrics, 2020
Rachel U Sidwell, Mike A Thomson
Torsades de pointes is an arrhythmia usually of short duration. The ECG has a prolonged QT between the tachycardias. The arrhythmia usually spontaneously reverts to sinus rhythm; however, it can convert to VF and result in sudden death.
Central nervous system depressants
Published in Ilana B. Crome, Richard Williams, Roger Bloor, Xenofon Sgouros, Substance Misuse and Young People, 2019
Side effects from therapeutic doses of methadone include overdose, sedation, constipation, fatigue, decreased libido, and weight gain. In addition, there is one methadone-related health consequence, which requires particular attention. The use of high doses (>100 mg) of methadone is associated with delays in the electrical conduction in the heart and may lead to a disruption of heart rhythm in susceptible patients. In some patients, this can lead to their developing a potentially fatal cardiac arrhythmia called torsade de pointes. A systematic review of the research evidence for cardiac screening prior to starting methadone prescribing concluded that the evidence from research was not of a sufficiently high quality for conclusions to be drawn (Pani et al., 2013) and the authors noted that none of the studies reviewed had considered people under the age of 18. Initial consensus guidelines published in the USA in 2009 advised screening all patients before and during methadone treatment. They suggest that a pre-treatment electrocardiogram should be performed to measure the QTc interval, with follow-up electrocardiograms performed within 30 days and annually (Krantz et al., 2009). The guidelines were met with criticism as some people’s opinion was that routine screening of all patients who are prescribed methadone was not an appropriate use of resources (Bart, 2009; Cohen and Mao, 2009).
QTc interval prolongation in patients with systemic lupus erythematosus treated with hydroxychloroquine
Published in Modern Rheumatology, 2021
Taihei Nishiyama, Yuya Kondo, Hiroto Tsuboi, Hisashi Noma, Daiki Tabuchi, Toshiki Sugita, Shota Okamoto, Toshihiko Terasaki, Masaru Shimizu, Fumika Honda, Ayako Ohyama, Izumi Kurata, Mizuki Yagishita, Saori Abe, Hiroyuki Takahashi, Atsumu Osada, Shinya Hagiwara, Isao Matsumoto, Takayuki Sumida
Regarding another risk factor for QTc prolongation with HCQ treatment, a recent study reported that patients with SLE with chronic kidney disease (CKD) had significantly greater QTc prolongation than patients without CKD [23], although our investigation showed that there was no significant difference in eGFR between HCQ-treated patients with and without QTc prolongation. Other studies revealed that patients with Covid-19 who were treated with HCQ at a dose of 400–1000 mg/day for 5–7 days showed greater QTc prolongation than those who were not receiving HCQ [4,5]. These reports suggested that decreased renal function or administration of high-dose HCQ could induce the increased blood concentration of HCQ and result in QTc prolongation. On the other hand, there was no observable correlation between QTc interval change and the duration of HCQ administration in our study, indicating that continuous HCQ administration is probably not a risk for highly elevated blood concentration of HCQ or increased risk of QT prolongation. Caution should be exercised in HCQ treatment for patients with SLE especially with risk factors of advanced age, long disease duration, or comorbid hypertension or CKD, and ECG should be checked at least once after the initiation of HCQ. Previous report about long-QT syndrome showed that the patients with QTc of 500 ms or more had a high risk of cardiac event including torsade de pointes [24]. Thus, HCQ should be discontinued when QTc interval increased to 500 ms or more, or cardiac events occurred.
Is kratom (Mitragyna speciosa Korth.) use associated with ECG abnormalities? Electrocardiogram comparisons between regular kratom users and controls
Published in Clinical Toxicology, 2021
Mohammad Farris Iman Leong Abdullah, Kok Leng Tan, Suresh Narayanan, Novline Yuvashnee, Nelson Jeng Yeou Chear, Darshan Singh, Oliver Grundmann, Jack E. Henningfield
Two in vitro studies have suggested that mitragynine may be associated with an increased risk for cardiotoxicity, but their relevance to human kratom users has not been confirmed. These laboratory findings showed that mitragynine can inhibit the human ether-a-go-go-related gene (hERG) which encodes for potassium channels involved in conducting the rapid inward and outward components of delayed rectifier potassium current (IKr). These potassium channels are essential for the repolarisation of action potentials in myocardial cells. This, in turn, prolongs the cardiac action potential and leads to a prolonged QT interval. Consequently, a prolonged QT interval will increase the risk of torsades de pointes. The inhibition of hERG encoded potassium channels is due to the interaction of mitragynine with a high-affinity drug binding site in the cavity of the hERG channel pore rather than to inhibition of the hERG mRNA. Mitragynine also inhibits the G protein-coupled inward rectifier potassium (GIRK) channel in a dose-dependent manner, and this leads to inhibition of the inward-rectifying potassium current (IKACh), which may produce added cardiotoxicity risks [13,14]. These studies suggest the possibility of cardiotoxicity in humans, but the generalisability to human kratom consumption warrants further study. The goal of our study was to investigate the prevalence of electrocardiogram (ECG) abnormalities in general and QTc intervals in particular in regular kratom users compared with non-kratom-using controls.
COVID-19: an unprecedented pandemia with a potential arrhythmic undertone
Published in Postgraduate Medicine, 2020
Angel Lopez-Candales, J Paul Mounsey
Subsequently, QTc prolongation was indeed demonstrated from data analysis of 84 patients receiving hydroxychloroquine and azithromycin [16]. These investigators from New York showed that even when the QTc interval prolonged from a baseline average of 435 ± 24 ms to a value of 463 ± 32 ms (P < 0.001), occurring approximately 3.6 ± 1.6 days after therapy was initiated [16]. Most importantly, no torsades de pointes were reported in any of these patients, even in those with the most prolonged QTc [16]. It is quite poignant to reconcile what might appear as a discrepancy between known data regarding QTc interval and hydroxychloroquine and azithromycin use. Surely, these drugs can result in just mild QTc prolongation when used in young healthy volunteers [17]. However, more significant QTc interval prolongation should be expected in COVID-19 patients based on the number of their co-morbidities and the extent of their respiratory and/or systemic inflammation severity [18]. Important clinical profiles that might increase the proarrhythmic potential include very high fever, profound electrolyte disturbances, that are further aggravated by vomiting and diarrhea, as well as hypoxia, concomitant use of antiviral drugs, underlying elevation in troponin levels and severe systemic inflammation [18,19,20].