Does Asthma Affect Heart Rate?

Asthma is a chronic disease that affects hundreds of millions of people worldwide. In 2019, according to the WHO, this disease claimed more than 400,000 deaths around the globe. In this article, we will take a close look at how this chronic respiratory condition influences the heart rate. We will also discuss the cardiovascular risks associated with asthma and provide insights into preventing these complications.
Jakub Gwiazdecki

Jakub Gwiazdecki

Fifth year medical student at the Medical Faculty of Comenius University in Bratislava.

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Does asthma affect heart rate?

Yes, asthma can affect heart rate. The primary reason is the impact this respiratory disease has on the autonomic nervous system, which controls heart rate.

Patients suffering from asthma have been found to have higher heart rates than healthy individuals. A comparison study found that asthmatics have a 10 bpm higher heart rate than non-asthmatics [2].

Asthma also affects heart rate variability (HRV), a measure of the physiological time variation between heartbeats. It can be used for autonomic nervous system evaluation. Asthmatic patients, who do not engage in physical exercise, have been found to have poor HRV [3].

The same applies to children and adolescents with asthma. Also, their HRV is low, indicating sympathetic modulation [4].

Why does asthma impact heart rate?

Asthma is an inflammatory disease that can significantly impact heart rate. The main pathway by which it influences the human pumping organ involves autonomic nervous system (ANS) modulation.

Asthma is associated with autonomic dysfunction. It leads to an imbalance between the sympathetic and parasympathetic parts of the components of the ANS.

The parasympathetic nervous system (PNS) is responsible for the calming effect on the heart. Its effect is mediated by the 10th cranial nerve, the vagus nerve. These nerves are also responsible for the parasympathetic innervation of the lungs.

In asthma, the vagus nerve is often found to be hyperactive. In the lungs, this causes bronchoconstriction and mucus hypersecretion [5, 6]. In the heart, high activity of the PNS leads to heart rate variability changes [7].

Asthmatics often show a lower HRV than healthy individuals [3, 4]. This is combined with a high heart rate, especially during asthma exacerbations [2].

Furthermore, the circadian heart rhythm of asthmatic individuals can be altered. The increased parasympathetic stimulation potentiated its effect, especially in the early morning hours. It is the time of the most frequent asthmatic attacks [8].

What are the cardiovascular risks of asthma?

Asthma is associated with an increased risk of cardiovascular disease (CVD). This is no surprise, as it is a chronic inflammatory disease that leads to an increase in the proinflammatory proteins in the vasculature.

The high inflammatory markers produced in asthma are associated with arterial injury. This condition is the starting point for the potential development of atherosclerosis. The subsequent buildup of obstructive plaques in the arteries is one of the most common causes of CVD, like heart attack and stroke [9].

Another risk is the development of hypertension. A consistent increase in blood pressure is one of the major risk factors for CVD [9]. Patients with untreated asthma can develop hypertension. However, the exact mechanism is not completely understood.

Patients with asthma have an increased risk for cardiovascular diseases like heart failure, heart attack, or stroke (50% higher risk)

Generally, asthmatic patients have an approximately 30% higher chance of death from cardiovascular diseases [12].

However, the risk of CVD is not the same for every asthmatic patient. The risk depends on many factors, like age, lifestyle, asthma control, and the clinical phenotypes and molecular endotypes of the disease [9].

Can you prevent cardiovascular complications of asthma?

The prevention of cardiovascular complications in asthma is a multi-factorial management strategy.

The first important step is the optimization of the therapy for asthma as well as already existing cardiovascular diseases. The adjustment should be made based on the evidence of the best-working medications. It should minimize the adverse effects on both pulmonary and cardiovascular conditions [13].

An example of a medication that is beneficial for both conditions is corticosteroids. They are inflammatory suppressors and reduce inflammation in asthma, as well as lower the risk of atherosclerosis development or progression [13].

The situation is different from other medications used in asthma management. For instance, β2-agonists, which are widely used in asthmatics, can have harmful effects on the cardiovascular system.

Although inhaled β2-agonists can have beneficial effects for patients with decompensated heart failure [13], in other cases they increase the risk for cardiovascular diseases. They increase the risk of myocardial infarction, congestive heart failure, cardiac arrest, and sudden cardiac death [14]. Therefore, in asthmatic patients with higher cardiovascular risk, or CVD, they have to be used with caution.

Another example of a drug with a potential negative impact on the system is aspirin. It is used to lower the risk of thromboembolic events in conditions like atrial fibrillation. It can cause hypersensitivity reactions and, thus, exacerbations of asthma. When a situation like this happens, substitutions like P2Y12 inhibitors should be considered. They include drugs like clopidogrel, prasugrel, and ticagrelor and are safe treatment alternatives [13].

Lastly, lifestyle changes and and risk factor management are very important. Risk factors that affect both the cardiovascular and pulmonary systems include hypertension, obesity, and dyslipidemia. These should be treated first [15].

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Jakub Gwiazdecki

Jakub Gwiazdecki

Jakub is in his fifth year as a medical student at Comenius University in Bratislava, Slovakia. He has special interested in cardiology and in patient-centered medicine. His love for heart health isn't just book-smarts; he wants to know how it works, what it means for our feelings, and how key it is for health and happiness. Jakub thinks real good health care comes from always putting the patient at the centre, treating each person as a whole.