Cardiac asthma isn't asthma in its true sense. It's wheezing due to congestive heart failure.
Cardiac asthma is a clinical condition caused by severe reflexive blocking and/or by edema of the lungs. It is an asthmatic-type breathing caused by sudden blockage of the pulmonary circulation. The bronchial spasm in cardiac asthma is caused by back pressure from the left side of the heart to the lungs (the left part of the heart has a sudden disproportion between its work load and work capacity).
Cardiac asthma is quite similar to lung asthma. In this, patients with heart failure or heart valves that do not open properly experience shortness of breath, wheezing and coughing.
What causes cardiac asthma?
Cardiac asthma is usually due to a major mechanical fault of the heart and may pose to be life threatening, if not checked at the right time.
In this kind of asthma, the reduced pumping efficacy of the heart leads to a build up of fluid in the lungs. This build up of the fluid causes the air passages to narrow up and eventually cause wheezing and other related symptoms.
Symptoms usually occur with exercise or at night after going to bed. Excessive fluid in the lungs associated with heart failure causes symptoms such as shortness of breath, coughing and wheezing, which imitate asthma.
Both cardiac asthma and pulmonary edema are symptoms of coming heart failure. It is a life-threatening condition and one must seek medical advice immediately on experiencing any symptoms.
Some of the main symptoms are:
- Shortness of breath, not necessarily accompanied by wheezing.
- Increased rapid and superficial breathing.
- Increased blood pressure and heart beat rate.
- A feeling of uneasiness.
- Cardiac asthmatic people wake up breathless a few hours after sleeping, and have to sit upright to again properly breathe. This is due to lying down too long.
- Swollen ankles which worsen rapidly during the stretch of the day.
The key to effective management of cardiac asthma is right diagnosis, which includes differentiation between patients who wheeze only due to acute heart failure vs those who wheeze from other disorders, such as asthma, chronic obstructive pulmonary disease, pneumonia or acute respiratory distress syndrome.
Treatment is directed at improving the pump function of the heart along with medications. If the asthma is caused by a heart valve that is not working properly or a hole between the heart chambers, surgery or other procedures may be suggested.
Treatments mainly focus on controlling the night coughs, control of the edema, control of inflow load and the amount of residual blood in the left ventricle.
Treatment of heart failure involves using diuretics (water pills) to free the lungs of excess fluid and medications to help the heart muscles pump more effectively. When the heart failure has been well controlled, the wheezing will gradually stop. Some people may suffer from asthma and heart failure simultaneously, and thus require treatment for both conditions.
Patients suffering from cardiac asthma generally respond well to a combination of bronchodilators, supplementary oxygen, and treatment of the heart failure.
Corticosteroids for a patient with acute cardiac asthma are only prescribed depending on clinical circumstances and the patient's response to initial therapy. When treatment of pure cardiac asthma is effective, the wheezing usually resolves automatically. Corticosteroids require several hours to give peak effect.
Who are prone to cardiac asthma?
Cardiac asthma usually occurs in elderly people who have wheezing and shortness of breath that are due to heart failure. When the heart is too weak to pump blood effectively, fluid will accumulate in the lungs. Fluid in the lungs causes shortness of breath and wheezing.