Criteria for referral to designated centres
When the general practitioner suspects that the patient may have PH, the patient should be referred as an out-patient for assessment by a cardiologist or chest physician. The cause of the patient’s symptoms will be sought, using investigations such as ECG, chest X-ray, spirometry and echocardiography.
Adults with confirmed or suspected pulmonary arterial hypertension (PAH), PH due to chronic thrombotic or embolic disease, pulmonary hypertension which appears to be out of proportion to lung disease or heart disease, another cause of PH, or where the cause is unclear, should be referred to a designated centre (see box), where cardiac catheterisation is carried out.1 Referral should not be delayed since some patients can deteriorate rapidly. Children in Great Britain should be referred to the UK Children’s Service if they have confirmed or suspected PAH.
A diagnostic algorithm to guide clinicians when faced with a patient with signs, symptoms or history suggestive of PH is shown in figure 1.2
Investigations for pulmonary hypertension
Whenever PH is suspected, patients must have a thorough diagnostic work-up: this is important in order to establish a precise diagnosis and to recommend the most appropriate treatment (see figure 1). Initial investigations comprise ECG, chest radiograph, lung function tests, echocardiogram and routine blood tests.
The ECG can provide evidence to support the diagnosis of pulmonary hypertension by showing right ventricular hypertrophy or strain, right atrial enlargement and right axis deviation of the QRS complex. A normal ECG does not exclude significant pulmonary hypertension. In idiopathic PAH, 80-90% of patients are likely to have an abnormal ECG on presentation.
In severe PH, atrial arrhythmias are often poorly tolerated. A finding of atrial fibrillation suggests underlying heart disease, pulmonary embolism or cor pulmonale as seen in chronic lung disease. Atrial arrhythmias should be suspected in patients with syncope in the absence of severe pulmonary hypertension. Atrial arrhythmias should also be suspected in any patient with sudden or rapid deterioration in symptoms of pulmonary hypertension in whom a diagnosis of PH is already established. Atrial flutter (figure 2),3 in particular, is common in this setting.
- The ECG may provide supportive evidence for a diagnosis of PH but the findings are non-specific