Asthma is a chronic respiratory condition characterized by inflamed and narrowed airways, leading to symptoms like wheezing, coughing, and shortness of breath. Individuals with asthma often wonder if the condition affects their heart rate. There is a connection between asthma and an increased heart rate, occurring due to the body’s physiological responses during an asthma attack or as a side effect of certain medications. Understanding this relationship helps individuals manage their health.
The Body’s Response During an Asthma Attack
During an asthma attack, several physiological changes can increase heart rate. Hypoxia, a lack of oxygen in the body’s tissues, is one factor. When airways constrict, inhaling enough oxygen becomes difficult, stressing the cardiovascular system. The heart then pumps faster to compensate for reduced oxygen supply.
The physical exertion involved in trying to breathe during an asthma attack also contributes to an elevated heart rate. The increased work of breathing, as the body struggles to move air through narrowed airways, requires more energy and places additional strain on the respiratory muscles. This heightened physical effort can cause the heart to beat more rapidly to meet the increased demand for blood flow to these working muscles.
An asthma attack also triggers the sympathetic nervous system, or “fight or flight” response. The body releases hormones like adrenaline and noradrenaline in response to this stress. These hormones naturally increase heart rate, blood pressure, and respiratory rate, preparing the body to cope.
Medication Effects on Heart Rate
Common asthma medications, especially bronchodilators, can also increase heart rate as a side effect. These medications, such as beta-agonists like albuterol, relax airway muscles to open them and improve breathing. However, these drugs can also stimulate beta-receptors located in the heart.
Activation of these cardiac beta-receptors increases heart rate. Both short-acting bronchodilators, used as rescue inhalers, and some long-acting bronchodilators can cause this effect. For example, a single dose of a beta-2 agonist can increase heart rate by approximately 9 beats per minute. This side effect is often transient, resolving as the medication’s effects wear off, though individuals may experience palpitations.
When to Seek Medical Care
Individuals with asthma should know when an increased heart rate requires medical attention. If the elevated heart rate is persistent or unusually high, especially if it doesn’t subside after rescue medication or once an asthma attack resolves, a healthcare professional should evaluate it. A heart rate consistently above 100 beats per minute during an attack may be concerning.
Medical attention is also advised if the increased heart rate is accompanied by other concerning symptoms. These include chest pain, severe shortness of breath that does not improve, dizziness, fainting, or a bluish tint to the lips or fingernails. Any new or worsening heart symptoms in an individual with asthma should prompt a consultation with a doctor. It is also important to consult a healthcare provider before making any changes to prescribed asthma medications, even if heart rate concerns arise.