The effects of exercise at high altitude on high-sensitivity cardiac troponin release and associated biventricular
Christopher John Boos1, Adrian Mellor, Joe Begley
1Department of Cardiology, Poole Hospital NHS Foundation Trust, Longfleet Rd. Poole, Dorset, BH15 2JB, UK, christopherboos@hotmail.com.
Background:
It has been consistently shown that heavy exercise leads to cardiac troponin (cTn) release and variable changes in post exercise cardiac function. This relationship has not been explored at increasing or significant high altitude (HA). This study assessed the effects of exercise at progressively increasing HA on high-sensitivity (hs)-cTnT levels and their relationship to biventricular cardiac function and severity of acute mountain sickness (AMS).
Methods:
Transthoracic echocardiograms, hs-cTnT levels and AMS scores were measured at rest at 1,300 m then repeated post exercise and 12 h later after progressive trekking to 3,440, 4,270 m and at 5,150 m (after trekking to 5,643 m) on 19 healthy subjects (age 35.4 ± years, 52.6 % males).
Results:
There was a detectable increase (>5 ng/L) in post exercise hs-cTnT with exercise at HA which became significant at 5,150 m (5.84 % at 3,440 m, 5.2 % at 4,270 m and 56.3 % at 5,150 m; p = 0.0005). Compared with baseline, HA to 5,150 m led to a significant rise in post exercise Lake Louis AMS scores (p < 0.001) pulmonary artery systolic pressure (PASP) (23.7 ± 3.8 vs 37.9 ± 11.7 mmHg: p < 0.001), cardiac output (5.2 ± 1.2 vs 7.5 ± 1.3 l/min; p < 0.001) and a fall in SpO2 (96.1 ± vs 77.4 ± 12.0 %; p < 0.001). There was no change in stroke volume (p = 0.10) or estimated filling pressures (E/E') of the left (p = 0.50) and right ventricles (p = 0.4). On multivariate analysis increasing cardiac output (p = 0.02) and PASP (p = 0.04) and decreasing SpO2 (p = 0.01) were the only independent predictors of increasing cTnT levels (overall R (2) = 0.23, p < 0.0001).
Conclusions:
Moderate intensity exercise at significant HA influences the post exercise increase in hs-cTnT without overt deleterious effects on cardiac function.
Related Concept Videos
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
01:20Exercise 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...
01:29Heart Failure II: Pathophysiology
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
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...