Breathlessness
Breathlessness usually means feeling short of breath on exertion. It can be subtler than that — some patients do not feel particularly breathless, but quietly modify what they do to stay within their limits. A useful question to ask is what you were able to do a year ago, and whether that is still true today. Family and friends are often the first to notice.
What causes breathlessness?
There are many possible causes, most commonly either a respiratory (lung) or cardiac (heart) one.
Cardiac causes include deteriorating heart pumping function, a poor blood supply to the heart muscle from coronary artery disease, heart rhythm disturbances (arrhythmias), and heart valve problems. Long-standing respiratory disease that suddenly worsens may also reflect a new cardiac problem on top.
How is breathlessness assessed?
If the breathlessness is felt to be cardiac, the workup is built around clinical examination, an ECG and an echocardiogram, with further tests as needed.
- Clinical examination — looks for arrhythmias, heart murmurs (suggesting valve disease), signs of fluid retention, and chest signs pointing to a respiratory cause.
- Electrocardiogram (ECG) — identifies rhythm abnormalities such as atrial fibrillation, evidence of previous heart attack, and other electrical clues.
- Ambulatory ECG monitoring — a 24-hour, 7-day or 14-day recording, used if a paroxysmal arrhythmia (such as intermittent atrial fibrillation) is suspected. An implantable loop recorder may be used for very infrequent episodes.
- Transthoracic echocardiogram (TTE) — the key test. Shows heart pumping function, all four valves, the size of the chambers, and the pressure in the lungs.
- Stress echocardiography — used to look for exertional causes, such as valve disease that worsens with exercise, or coronary artery disease.
- Cardiac MRI — gives detailed information on heart muscle, the right ventricle, and any scar tissue or inflammation. Useful where the cause of impaired heart function is unclear or where a cardiomyopathy is suspected.
- CT coronary angiography — a non-invasive scan of the coronary arteries when ischaemia is on the differential.
- Blood tests — full blood count (anaemia is a common contributor to breathlessness), thyroid function, BNP, kidney function and iron studies.
- Lung function tests / chest X-ray — to evaluate any respiratory contribution.