"Introduction
... Hydroxychloroquine was among the first treatments available and tested for COVID-19, however, it did raise concerns among the medical community for its potential risks on cardiac rhythm. There have been several controversial issues regarding treatment with Hydroxychloroquine published by the FDA, announcing that Hydroxychloroquine prolongs the QTc intervals of patients over time during treatment, causing Torsade de Pointes (polymorphic ventricular tachycardia) and other cardiac problems. We seek to determine whether studies based in the hospital vs. ambulatory studies, where patients are treated while at home, lead to differing results in the effort to treat COVID-19, and most importantly, whether Hydroxychloroquine is associated with heart irregularities as evaluated by QTc intervals measurements.
Methods
Study Subjects and Study Design
... Between June 2020 to June 2021, 118 COVID-19 patients were approached, of which 83 were recruited for a Double-Blind Randomized Placebo-Controlled Trial of Quintuple Therapy... The 83 included subjects were stratified for the double-blind placebo-controlled clinical trial, arm 1 and arm 2 groups: 52 patients were randomly assigned to receive HAZDPac [Hydroxychloroquine paired with Azithromycin, Vitamin C, Vitamin D, and Zinc] treatment, and 31 patients to receive placebo. We kept the treatment blinded to ensure validity of results and data...
Discussion
We found that hydroxychloroquine in conjunction with other drugs used in standard-of-care for ambulatory acute COVID-19 did not impact the QTc interval measured in an assiduous continuous monitoring environment. Hydroxychloroquine has been a controversial drug due to the speculation that either alone or paired with azithromycin taken orally leads to a prolonged QTc interval and Torsade de Pointes, particularly in an inpatient hospital setting. Yet, in this outpatient setting study conducted by ProgenaBiome, a private research clinic located in Ventura, California, such cardiac findings of patients treated with Hydroxychloroquine, paired with Azithromycin, Vitamin C, Vitamin D, and Zinc (HAZDPac) did not reflect previous concerns. The mean maximum QTc value found in the data we gathered from treated patients' continuously worn EKG monitor was 437 ms (SD=32), which falls into the normal range for both males and females, QTc normal range for males is 350-450 ms, and for females is 360-460 ms."
QTc Interval
https://www.sciencedirect.com/topics/medicine-and-dentistry/qtc-interval
"The QT interval is a reflection of the total action potential duration for ventricular myocytes... Because the normal QT interval varies with heart rate (longer at slow rates, shorter at fast rates), the measurement is adjusted with the formula: QT (seconds)/square root R-R (seconds). This rate-corrected interval (QTc) should be less than 0.45 second in infants, 0.44 second in children, and 0.43 second in adults. A prolonged QTc interval can be of dramatic clinical significance."
This article was first published under the following title in BMC Cardiovascular Disorders:
Cardiac findings in a phase II double-blind randomized placebo-controlled trial of combination therapy (HAZDPac) to treat COVID-19 patients
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