The QT interval and cycle length: the influence of atropine, hyoscine and exercise

British Journal of Clinical Pharmacology
D H Staniforth

Abstract

Twenty-seven healthy male subjects of mean age 24.3 +/- 4.0 years and mean weight 74.9 +/- 9.1 kg took part in an investigation to assess the most suitable correction for the QT interval as a function of cardiac cycle length. 547 sets of data points were generated. Atropine 0.6, 1.2 and 1.8 mg, and hyoscine 0.4 and 0.8 mg, and exercise on a bicycle ergometer at power levels of 50-250 watts together with post-exercise values were employed to obtain a range of heart rates. Simultaneous measurement of cardiac output and total peripheral resistance were made. It was found that the traditional square root formula gave an unsatisfactory correction for the QT for supine subjects following atropine and hyoscine. The formula K = QT/RRN was linearized and fitted to the data by the least squares method and gave a best fit correction with N = 0.35, which is close to the cube root correction of Fridericia (1920). Neither stroke volume nor total peripheral resistance were found to provide a further enhancement of the correction. The relationship between QT and cycle length following the exercise protocol was found to be best represented by Bazett's correction but the complex changes in the QT produced by exercise were noted. These findings s...Continue Reading

References

Aug 1, 1978·British Journal of Clinical Pharmacology·D G Gibson
Nov 1, 1978·British Journal of Clinical Pharmacology·S M BrysonJ R Lawrence
Aug 1, 1976·American Heart Journal·J A Abildskov
Sep 1, 1976·Clinical Pharmacology and Therapeutics·R L GaleazziL B Sheiner
Mar 1, 1975·Medical & Biological Engineering·D W Hill, F D Thompson
Jan 1, 1983·European Journal of Clinical Pharmacology·D H Staniforth
Jun 1, 1962·American Heart Journal·E SIMONSONM WOODBURY
Jun 1, 1950·Circulation·M M ALIMURUNGB F MASSELL
Jul 1, 1936·The Journal of Clinical Investigation·W Adams
Mar 1, 1950·The Journal of Clinical Investigation·P N YuR Pearson

Citations

Jan 1, 1992·Archives of Toxicology·Z DurakovicD Ivanovic
Mar 1, 1987·The American Journal of Cardiology·S VozehF Follath
Sep 1, 1997·Journal of the American College of Cardiology·L ToivonenM Viitasalo
Feb 1, 1988·Postgraduate Medical Journal·H A CameronL E Ramsay
Sep 15, 1992·The American Journal of Cardiology·A SagieD Levy
Sep 1, 1988·Progress in Cardiovascular Diseases·W M JackmanR Lazzara
Feb 1, 1985·British Journal of Clinical Pharmacology·D W HarronR G Shanks
Jun 1, 1985·British Journal of Clinical Pharmacology·B K Martin
May 1, 1987·Pacing and Clinical Electrophysiology : PACE·P Rossi
Jul 1, 1984·British Journal of Clinical Pharmacology·A W KelmanD J Summer

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Hereditary Sensory Autonomic Neuropathy

Hereditary Sensory Autonomic Neuropathies are a group of inherited neurodegenerative disorders characterized clinically by loss of sensation and autonomic dysfunction. Here is the latest research on these neuropathies.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.

Glut1 Deficiency

Glut1 deficiency, an autosomal dominant, genetic metabolic disorder associated with a deficiency of GLUT1, the protein that transports glucose across the blood brain barrier, is characterized by mental and motor developmental delays and infantile seizures. Follow the latest research on Glut1 deficiency with this feed.

Separation Anxiety

Separation anxiety is a type of anxiety disorder that involves excessive distress and anxiety with separation. This may include separation from places or people to which they have a strong emotional connection with. It often affects children more than adults. Here is the latest research on separation anxiety.

KIF1A Associated Neurological Disorder

KIF1A associated neurological disorder (KAND) is a rare neurodegenerative condition caused by mutations in the KIF1A gene. KAND may present with a wide range and severity of symptoms including stiff or weak leg muscles, low muscle tone, a lack of muscle coordination and balance, and intellectual disability. Find the latest research on KAND here.

Regulation of Vocal-Motor Plasticity

Dopaminergic projections to the basal ganglia and nucleus accumbens shape the learning and plasticity of motivated behaviors across species including the regulation of vocal-motor plasticity and performance in songbirds. Discover the latest research on the regulation of vocal-motor plasticity here.

Related Papers

British Journal of Clinical Pharmacology
A W KelmanD J Summer
IEEE Engineering in Medicine and Biology Magazine : the Quarterly Magazine of the Engineering in Medicine & Biology Society
N E FearnotH J Smith
Pacing and Clinical Electrophysiology : PACE
P E Puddu, J Torresani
© 2021 Meta ULC. All rights reserved