Colorado may
seem like the place to move to but is it really safe for those with
pre-existing, severe cardiac issues? According to Khodaee et al. (2016), high
elevations (2000 to 3000 m utilized in their study) can induce states of
hypoxia as O2 levels decrease from normal, ~21% at sea level (Khodaee et al.,
2016). Colorado has a mean elevation of 2,070 m with O2 levels ranging from
15.4% in Aspen (elevation at 2,400 m), and 12.3% at Pikes Peak (elevation at
4,302 m) (Mile High Training, n.d.). So how does high altitude affect the
heart? With less O2 around, this can lead to your heart working harder and
faster in order to maintain proper O2 levels throughout the body. Thus, if you
are a healthy person with stable to no pre-existing cardiac issues, this will,
hopefully, lead to an acute response: increased heart rate, contractility, and
cardiac output until one is able to acclimate. Despite knowing this, research
is very elusive regarding the effects of those with severe CAD and high
altitude given that effects can vary largely on the individual, the level of
activity, and/or even the weather (Rimoldi et al,. 2010; Parati et al., 2018).
This suggests that further research should be conducted in order to ensure the
safety of those with severe CAD who are ascending to higher elevations.
According to the CDC (2020), heart disease is also one of the leading causes of death, costing the United States about $219 billion from 2014-2015. The most common heart disease is CAD which about 18.2 million adults have (CDC, 2020). As future healthcare providers, this should raise red flags for us especially in the context of treatment. Moreover, due to the high prevalence, this should facilitate more urgency in researching severe CAD and factors, such as high elevation, in order to effectively treat and advise patients.
CDC. (2020).
Heart Disease Facts. Retrieved November 1, 2020, from https://www.cdc.gov/heartdisease/facts.htm
Khodaee, M., Grothe, H. L., Seyfert, J.
H., & VanBaak, K. (2016). Athletes at High Altitude. Sports Health, 8(2), 126–132. https://doi.org/10.1177/1941738116630948
Mile High Training. Mile High Training Altitude to Oxygen Chart. (n.d.), Retrieved from https://milehightraining.com/altitude-to-oxygen-chart/
Parati, G., Agostoni,
P., Basnyat, B., Bilo, G., Brugger, H., Coca, A., Festi, L., Giardini, G.,
Lironcurti, A., Luks, A. M., Maggiorini, M., Modesti, P. A., Swenson, E. R.,
Williams, B., Bärtsch, P., & Torlasco, C. (2018). Clinical recommendations
for high altitude exposure of individuals with pre-existing cardiovascular
conditions: A joint statement by the European Society of Cardiology, the
Council on Hypertension of the European Society of Cardiology, the European
Society of Hypertension, the International Society of Mountain Medicine, the
Italian Society of Hypertension and the Italian Society of Mountain Medicine. European heart journal, 39(17), 1546–1554.
https://doi.org/10.1093/eurheartj/ehx720
Rimoldi, S. F., Sartori, C., Seiler, C.,
Delacrétaz, E., Mattle, H. P., Scherrer, U., & Allemann, Y. (2010).
High-altitude exposure in patients with cardiovascular disease: risk assessment
and practical recommendations. Progress
in cardiovascular diseases, 52(6),
512–524. https://doi.org/10.1016/j.pcad.2010.03.005
Christina, before reading your blog post, I never considered the effects of living in high altitudes and how it could increase the risk of certain cardiac issues. It totally makes sense that your heart would have to work harder in areas where oxygen is less available. But one study I found considered people living in high altitudes may be developing certain anatomic, physiological, and metabolic adaptations that could actually be beneficial (Bhatnagar, 2017). The study stated that people permanently living in higher elevations rarely exhibit high systolic hypertension and have lower cholesterol (LDL) and higher HDL levels (Bhatnagar, 2017). Additionally, permanent residence in higher altitude could be correlated to decreased risk of cardiovascular disease and mortality. This correlation could be attributed to differences in diet, physical activity levels, and air pollution. Thus, lifestyle choices could potentially account for better cardiovascular health in individuals living in higher altitude.
ReplyDeleteWith the differences between the studies we found, I believe it is important for further research to be conducted regarding the correlation between high altitude and risk for cardiovascular problems. At this point in time, there isn't enough evidence to support that higher altitude significantly influences the risk of cardiac problems.
Bhatnagar, A. (2017). Environmental Determinants of Cardiovascular Disease. Circulation Research, 121(2), 162-180. doi:10.1161/circresaha.117.306458
Hi Christina,
ReplyDeleteI love that you brought this up as it is topic that we do not think about, but we ought to as we are going to see a lot of patients with CAD or some heart condition. I know from my experience working in a family medicine setting, that it can be quite difficult to give advice to patients when they want to travel or do a light hike. I found a study that analyzed 29 stable heart failure (HF) patients and their tolerance to light exercise at a elevation of 3454 m (higher than Denver). At the end, it appears that all of the subjects tolerated exercise well as none of them had to terminate the experiment early and there was no difference in premature ventricular contractions (Schmid et al., 2015).
Although it seems like a CAD-body can tolerate high-altitudes decently, I agree that there is not a lot of research to confirm it. I believe that it is generally safe to advise patients to avoid exercising in high altitudes if they have CAD, but each patient is different and handles the condition they carry differently as well. Perhaps for the time being, we may be able to advise patients that they can possibly exercise in higher altitudes, depending on how they are clinically as they present themselves.
References:
Schmid, J., Nobel, D., Brugger, N., Novak, J., Palau, P., Trepp, A., Wilhelm, M., Saner, H. (2015). Short‐term high altitude exposure at 3454 m is well tolerated in patients with stable heart failure. European Journal of Heart Failure, 17(2).