Decoding Audible Wheezing: Understanding Its Link to Heart Failure

As a respiratory therapist, I have observed a curious phenomenon: People with heart failure (HF) may have audible wheezing, even when their condition is stable. While this may seem perplexing at first, understanding the underlying reasons can shed light on this aspect of heart failure.

What causes an audible wheeze in heart failure?

Wheezing typically arises when the airways in the lungs narrow, resulting in a whistling sound when you exhale. This narrowing can occur due to various factors, including increased mucus and/or bronchospasm. Bronchospasm is where the muscles around your airways contract and constrict them.

Traditionally, wheezing has been associated with respiratory conditions like asthma. For thousands of years, if you experienced wheezing you were almost always diagnosed with asthma. Around the year 1900, doctors realized that heart failure may also cause a wheeze. And when this was the case, they started calling this type of wheeze a cardiac wheeze. This is why heart failure is sometimes referred to as “cardiac asthma.”¹

However, in the context of HF, wheezing can occur due to fluid buildup in the lungs. This fluid buildup can lead to airway narrowing throughout your respiratory tract. It can affect both smaller and larger airways.

When the larger airways are affected, wheezing becomes audible. Doctors do not need a stethoscope to hear it. This audible wheezing may occur once in a while or all the time and its intensity can vary depending on factors such as fluid retention and overall heart function.

How do you tell the difference?

It's important to distinguish between wheezing in heart failure and wheezing in asthma. While wheezing in asthma primarily stems from constriction in the smaller airways, wheezing in HF results from airway narrowing caused by fluid buildup in the respiratory system.

This difference is essential for accurate diagnosis and management. Asthma treatments focus on relieving bronchoconstriction and inflammation. But managing wheezing in heart failure requires addressing underlying cardiac issues, such as fluid overload and impaired heart function.

Also, the presence of audible wheezing in people with heart failure can serve as a valuable clinical sign. It may signal worsening fluid retention or heart function. It can prompt healthcare providers to adjust medications or start other new treatments.

My observations of audible wheezing in people with heart failure

Throughout discussions with fellow respiratory therapists over the past year, a consistent observation has emerged: Audible wheezing is common among people with heart failure in the hospital. So, an audible wheeze triggers consideration of the possibility of HF.

Since wheezing is a hallmark symptom of asthma and COPD, we initially consider bronchodilator therapy. But it's crucial to recognize that this approach may not be effective if the wheeze stems from HF. Despite the ease of giving bronchodilators via inhaler or nebulizer, and their generally minor side effects, they are not very effective at relieving wheezing linked to HF.

Audible wheezing may vary in intensity. While it may be more pronounced during exacerbations, it can last even on days when heart failure symptoms are stable. In fact, I recently discharged a person with heart failure who still had audible wheezing. This shows how persistent this symptom can be despite optimal treatment.