Related Experiment Video
Updated: Aug 9, 2026
Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats
Published on: June 28, 2019
Coronary blood flow after cold exposure and the effect of warm-up exercise
Hyung-Kwan Kim1, Dae-Won Sohn, Sang-Eun Lee
1Division of Cardiology, Department of Internal Medicine, Seoul National University College of Medicine, Chongno-gu, Seoul, Korea.
Background:
Cold pressor test (CPT) results indicate that coronary blood flow (CBF) increases after sudden cold exposure. Traditionally, warm-up exercise (WEx) has been recommended before cold exposure; however, the physiologic effects of WEx on CBF have not been elucidated. Therefore, this study was undertaken to evaluate the effect of WEx on CBF after cold exposure.
Methods:
Fifteen healthy young men were enrolled in this study. CBF at the distal left anterior descending coronary artery was assessed by transthoracic Doppler echocardiography at baseline and after CPT. The same measurements were made with WEx and weight-bearing exercise before CPT after a 20-minute recovery period between each measurement. In the CBF velocities, the time-velocity integral of diastolic flow (Dtvi) was measured in addition to blood pressure and heart rate (HR).
Results:
The product of Dtvi x HR increased significantly after CPT. Increments in Dtvi x HR after CPT with WEx before CPT were significantly higher than CPT alone (130 +/- 82% vs 68 +/- 37%, P < .05). However, increments in Dtvi x HR after CPT with weight-bearing exercise before CPT were not significantly different from those observed for CPT alone (74 +/- 50% vs 68 +/- 37%, P = not significant).
Conclusion:
Our study suggests that WEx can augment an increased CBF after cold exposure. This augmentation of CBF increase after cold exposure may help the body meet increased physiologic demands imposed on it by cold exposure. However, this phenomenon was not observed for anaerobic weight-bearing exercise.
More Related Videos
Related Concept Videos
01:20Exercise and Cardiovascular Response
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...
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be met...
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
01:26Exercise Stress Test
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
01:22Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...