Related Experiment Video

Updated: Aug 19, 2026

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine
12:37

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

Published on: February 9, 2016

Diurnal variation in exercise responses in angina pectoris

M Joy, C M Pollard, T O Nunan

    British Heart Journal
    |August 1, 1982
    PubMed

    Insights

    Circadian variations in exercise ST segment response exist in angina patients, impacting assessment. This diurnal variation, linked to reduced vagal tone, requires consideration when evaluating treatment efficacy.

    Area of Science:

    • Cardiology
    • Chronobiology
    • Exercise Physiology

    Background:

    • Stable angina patients exhibit diurnal variations in cardiovascular responses to exercise.
    • Understanding these circadian rhythms is crucial for accurate patient assessment and treatment comparison.

    Purpose of the Study:

    • To investigate diurnal variations in exercise electrocardiography (ECG) responses in patients with stable angina.
    • To explore the influence of propranolol on these diurnal variations.
    • To assess potential training effects from repeated exercise testing.

    Main Methods:

    • Symptom-limited exercise ECG was performed on male patients with stable angina at different times of day (0800, 1200, 1600 hours).
    • Patients were grouped based on treatment (no treatment or propranolol).
    • Normal subjects were included as controls to assess diurnal heart rate variation and propranolol effects.

    Main Results:

    • Significant diurnal variation in heart rate and ST segment displacement was observed in untreated angina patients tested on the same day.
    • This circadian variation in ST segment response persisted even with propranolol treatment.
    • Repeated exercise testing on the same day suggested a possible training effect on heart rate.
    • Normal subjects showed no diurnal heart rate variation, but propranolol reduced their heart rate response.

    Conclusions:

    • A circadian variation in the ST segment response to exercise exists in angina patients, influenced by reduced vagal parasympathetic tone.
    • This diurnal variation must be considered when assessing angina patients and comparing treatment responses.
    • Potential training effects from serial exercise testing warrant further investigation.

    More Related Videos

    Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans07:26

    Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans

    Published on: October 17, 2018

    Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training07:40

    Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training

    Published on: October 10, 2019

    Related Concept Videos

    Exercise and Cardiovascular Response01:20

    Exercise and Cardiovascular Response

    Exercise significantly impacts cardiovascular response, which is crucial for understanding patient health and designing effective treatment plans.
    Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
    Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response01:15

    Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response

    Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
    The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
    Exercise Stress Test01:26

    Exercise Stress Test

    Introduction
    Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
    Definition
    An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
    Purposes
    Angina I: Introduction01:30

    Angina I: Introduction

    Definition and Symptoms: Angina (angina pectoris) is chest pain or discomfort caused by myocardial ischemia, which occurs when the heart muscle receives insufficient oxygen-rich blood. It typically manifests as pressing, squeezing, or crushing sensations in the chest and may radiate to the shoulders, arms, neck, jaw, or back.Primary Cause: In a healthy state, the coronary arteries can dilate (widen) to increase blood flow and meet the increased oxygen demand during physical activity or...
    Angina II: Classification01:27

    Angina II: Classification

    Angina, also known as angina pectoris, is a chest pain resulting from diminished blood flow to the heart muscle and is often a symptom of coronary artery disease. Angina presents several variants with distinctive attributes, etiologies, and therapeutic approaches. The main types of angina include stable, unstable, variant (Prinzmetal's), microvascular, intractable, and silent ischemia.Stable angina is caused by atherosclerosis, which leads to the formation of plaques that narrow the coronary...
    Angina III: Clinical Manifestations and Assessment01:29

    Angina III: Clinical Manifestations and Assessment

    Angina manifests as chest pain, tightness, or squeezing discomfort typically located behind the breastbone. It can radiate to the neck, jaw, shoulders, and inner aspects of the upper arms, most commonly the left arm. Patients may experience shortness of breath, fatigue, profuse sweating, dizziness, indigestion, heartburn, palpitations, anxiety, and vomiting as accompanying symptoms. This pain often lasts a few minutes and is triggered by physical exertion, emotional stress, heavy meals, or cold...