Resting heart rate during illness
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Resting Heart Rate and Illness: Key Health Outcomes
Resting heart rate (RHR) is a simple but important measure that reflects the body’s physiological state and can change during illness. It is influenced by factors such as sympathetic and parasympathetic nervous system activity, and it often increases in response to stress, fever, or infection as part of the body’s response to illness 19.
Resting Heart Rate as a Predictor of Disease Severity and Mortality
A higher RHR is consistently linked to worse health outcomes in both healthy individuals and those with existing medical conditions. Studies show that an increase in RHR is associated with a higher risk of cardiovascular diseases, including coronary artery disease, stroke, heart failure, and sudden cardiac death 24567810. This relationship is generally linear, meaning that as RHR increases, so does the risk of these outcomes 245610.
Resting Heart Rate During Acute and Chronic Illness
During acute illness, such as infection or myocardial infarction, RHR often rises and can reflect the severity of the disease. In patients recovering from myocardial infarction, a higher RHR during the stable phase is linked to an increased risk of death, heart failure, and recurrent heart problems . Similarly, in patients with heart failure, each 10-beat-per-minute increase in RHR is associated with a significant rise in the risk of death, especially in older adults .
Resting Heart Rate and Non-Cardiovascular Diseases
Elevated RHR is not only a marker for heart-related conditions but is also associated with a higher risk of non-cardiovascular diseases, including cancer and other causes of death 248. This suggests that RHR is a general indicator of overall health and physiological stress.
Resting Heart Rate in Special Populations
In patients with hematological diseases undergoing stem cell transplantation, the relationship between RHR and survival is more complex. One study found that the best outcomes were seen at an RHR of around 70 beats per minute, with both higher and lower rates linked to worse survival, suggesting a "bathtub" shaped relationship rather than a simple linear one .
Genetic and Lifestyle Factors Affecting Resting Heart Rate
Genetics play a role in determining RHR, and some genetic variants are linked to increased risk of certain heart diseases. However, the direct genetic link between RHR and overall mortality is less clear 78. Lifestyle factors such as physical activity, body weight, and blood pressure also influence RHR, but the association between RHR and disease risk remains even after accounting for these factors .
Clinical Implications and Monitoring
RHR is easy to measure and can be tracked using wearable devices, making it a useful tool for both patients and clinicians to monitor health, especially during illness 89. While interventions to lower RHR may benefit certain patient groups, there is not yet clear evidence that lowering RHR in healthy people improves outcomes 18.
Conclusion
Resting heart rate is a valuable indicator of health during illness. Higher RHR is generally associated with increased risk of cardiovascular and non-cardiovascular diseases, as well as higher mortality. Monitoring RHR during illness can provide important information about disease severity and prognosis, but the optimal RHR may vary depending on the specific illness and patient population.
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