Related Experiment Video
Updated: Jul 13, 2026

Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions
Published on: June 5, 2019
C-reactive protein is associated with heart rate variability
Trine Madsen1, Jeppe Hagstrup Christensen, Egon Toft
1Department of Cardiology, and Center for Cardiovascular Research, Aalborg Hospital, Arhus University Hospital, Denmark. tmadsen@dadlnet.dk
Background:
The aim of this study was to investigate the relation between low-grade inflammation and autonomic dysfunction, both of which may be risk markers for sudden cardiac death.
Methods:
A total of 269 subjects referred for elective coronary angiography because of clinically suspected coronary heart disease were included in the study. Of these 27% had a previous myocardial infarction and 70% had significant coronary stenoses. A 24-hour Holter-recording was obtained from all subjects, and time-domain heart rate variability indices were analyzed. C-reactive protein was measured using a high-sensitivity assay.
Results:
Mean SDNN was significantly higher in the lower compared to the upper hs-CRP quartile (140 +/- 34 ms vs 113 +/- 29 ms; P < 0.001). Similar results were found for SDNNindex (54 +/- 16 ms vs 46 +/- 12 ms; P = 0.002) and SDANN (125 +/- 33 ms vs 101 +/- 31 ms; P < 0.001). The association was strongest for subjects with a previous myocardial infarction, subjects with significant coronary stenoses, and males. In a linear regression analysis, hs-CRP remained an independent determinant of each of these three heart rate variability indices (all P < 0.001).
Conclusion:
C-reactive protein and heart rate variability are independently associated. This may support a link between low-grade inflammation and autonomic dysfunction.
Related Concept Videos
Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
Blood Studies for Cardiovascular System II: CRP, Hcy, and Cardiac Natriuretic Peptide Markers
These markers indicate stress or strain on the heart muscle:
Natriuretic Peptides (BNP)
Cardiac myocytes produce these hormones in response to ventricular stretching...
Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies
Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
Cardiac 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...

