Cardiac Asthma -- What You Need to Know
Last updated: April 2022
Have you ever heard of a condition called "cardiac asthma"? Have you wondered if it's the same as the asthma of the airways you and/or your grandchildren have been dealing with? Or maybe it's a complication of your asthma that you may be at risk for developing?
Actually, none of those are true. Cardiac asthma is a totally separate condition from bronchial asthma. In fact, it's more a set of symptoms than it is an actual medical diagnosis. It's not really even asthma, despite the term commonly used. Let's take a closer look.
What is cardiac asthma?
Cardiac asthma is a term coined by a medical doctor named James Hope back in 1833. He used it to describe inadequate oxygenation of blood and the breathlessness that comes from that.1 Although it is often confused with the more common bronchial asthma, physicians today understand that there are some essential differences between the two conditions.
How cardiac asthma and bronchial asthma are different
The main difference is that cardiac asthma is not really asthma at all. Rather, it is a set of symptoms that are similar to those caused by true asthma, but with a different root cause. Other differences include:
- Asthma, which is sometimes referred to as "bronchial asthma," is caused by inflammation of the airways. This is generally in response to allergens, substances that cause an allergic reaction. Or sometimes, the inflammation can be triggered by environmental factors, such as strong fumes, air pollution, or tobacco smoke.
- Cardiac asthma symptoms are caused by congestion in the lungs that is the result of heart failure.1
- Bronchial asthma is more common in children, although it can occur at any age. On the other hand, cardiac asthma symptoms are more common in older adults, who are more likely to have heart problems.
- Experts are not sure what causes bronchial asthma, although there does seem to be a genetic link in many cases. In cardiac asthma, the heart’s inability to pump blood out of the left ventricle causes fluid to back up into the lungs. There can be various reasons why the heart fails to pump effectively.
How cardiac asthma and bronchial asthma are similar
Both conditions have similar symptoms, namely:1,2
Also, the symptoms in both conditions tend to be worse at night, while sleeping and lying flat. And, although these symptoms may be somewhat similar, with cardiac asthma, the patient may cough up watery or frothy sputum. This does not happen with bronchial asthma.1
It's important to note that while the root cause of cardiac asthma is different than bronchial asthma, there can be a bit of a crossover between the 2 conditions. That is, while the backup of fluid in the lungs can cause breathing difficulties, it may also trigger a narrowing or blockage of the airways themselves. Experts believe the airways may actually become hyperreactive in cardiac asthma, similarly to what happens in bronchial asthma.1 We are not sure exactly why this happens.
However, because the root cause of cardiac asthma symptoms is not inflammation, diagnosis and treatment will be much different.
Cardiac asthma often causes a sudden awakening with severe shortness of breath. If the patient sits up straight for 20 to 30 minutes, the symptoms often subside on their own.1 Typically, a severe bronchial asthma attack will not subside without the use of a rescue, or quick-relief, inhaler.
Sometimes, the cardiac asthma patient will wake up several times in a single night. The symptoms can become progressively worse, including:1
- Cyanosis (blue-tinged skin, lips or fingernails)
- Cold sweats
- Coughing up blood-tinged mucus
Diagnosing cardiac asthma is not as easy as it might seem. Not only are many of the symptoms similar to bronchial asthma, they are also similar to congestive heart failure. Wheezing is considered a hallmark symptom of cardiac asthma vs. heart failure alone, though.1
Chest x-rays, a thorough medical history, and other cardiac tests can help the doctor figure out exactly what the patient is dealing with.
Because the root cause of cardiac asthma is not inflammation, treatment is totally different. Inhaled steroids, bronchodilators, and other typical asthma medications are not useful with this condition.
Instead, treatment focuses on relieving the underlying heart issues that led to the fluid build-up in the lungs. This may include diuretics to remove the fluid. Nitroglycerin and morphine may also be used to reduce the stress on the heart.
Supplemental oxygen may be used in some cases. Proper positioning while sleeping is also crucial. In other words, the head of the bed should be raised in some way to avoid the patient lying flat. During an acute episode, the patient may even need to stand or sit completely erect with feet hanging below heart level.1,3
The symptoms of cardiac asthma should not be taken lightly, as they can be life-threatening. This is why it's important to distinguish this from the generally less severe bronchial asthma. The good news is that prompt, intensive treatment can lead to rapid, positive improvement.
It's never wise to try and diagnose yourself. Just because you are having some of the hallmark symptoms of asthma, doesn't mean you really have asthma. If you are having wheezing, shortness of breath and coughing, especially if those symptoms wake you up suddenly while sleeping, it's time to consult your doctor.
This is especially true if you are an older adult and if you have any history of heart problems. It could be that what you are experiencing is really the syndrome known as cardiac asthma, which isn't really asthma at all.
Have you experienced cardiac asthma?
How often do you experience a shortage in your asthma medication?