When 49-year-old Mary sat herself down it was immediately apparent that she wasn't her usual positive self.
She explained that for the past three months she had felt increasingly breathless on exercise together with a feeling of pressure in her chest, both of which were relieved by rest.
There had been no accompanying cough or sputum production, no wheezing and no suggestion that symptoms were worse at night-time.
Mary did not have an atopic history, had no chronic health problems and was taking no regular medication. She had smoked around 20 cigarettes a day before quitting in her mid-thirties. She had no obvious exposure to other respiratory irritants. Her father had died from an MI in his late forties.
Examination didn't add anything positive to the history. Mary was normotensive with a regular pulse of 78, no heart murmurs, a clear chest with reasonable air entry and no ankle or calf swelling.
My initial impression was that Mary's symptoms might represent IHD, and I arranged for her to have baseline bloods, an ECG and a chest X-ray.
Her total cholesterol came back at 7.1mmol/l with a cholesterol/HDL ratio of 4.5 while FBC, U&E, LFT, TFT and fasting blood glucose tests were within normal limits.
However, the ECG didn't look normal, with T-wave inversion in leads V1 to V4 together with ST depression in the anterior leads and right axis deviation, which I took as being supportive of the diagnosis of IHD and possibly indicating right ventricular hypertrophy. I followed this up with an urgent cardiology referral.
She was started on aspirin, simvastatin and a beta-blocker and she appeared to have a positive response to a nitrolingual spray. By now Mary's chest X-ray revealed cardiomegaly and small bilateral pleural effusions that suggested cardiac failure.
The cardiologist immediately arranged an echocardiogram, with surprising and disturbing results. The right side of the heart was found to be dilated with severely elevated pressures but with no evidence of a septal defect that might account for these features.
Certainly Mary had pulmonary hypertension and investigations were now directed toward finding a cause.
A CT pulmonary angiogram found no evidence of pulmonary emboli and an autoantibody screen for a vasculitic cause of pulmonary hypertension was negative.
Lung function tests were consistent with mild obstructive airways disease but nowhere near the degree that might account for Mary's symptoms or the severe pulmonary hypertension. Blood gases revealed marked hypoxia. The presumptive diagnosis then was primary pulmonary hypertension (PPH).
The cardiologist started Mary on nifedipine and, because of the high risk of pulmonary emboli in PPH, warfarin. Continuous oxygen raised her oxygen saturation from 75 per cent to 94 per cent. She was also referred on to a tertiary centre for management of her PPH.
Pulmonary hypertension most commonly arises secondarily to either chronic lung disease, pulmonary vascular disease or a cardiac cause. Much less frequently, with an estimated incidence of 1-2 per million per year in the UK and a female preponderance, the cause is PPH where the cause of the increased pulmonary vascular resistance remains unknown.
Normal pulmonary artery systolic BP is no more than 25mmHg at rest, contrasting strongly with Mary's, which was 103mmHg. The consequence of elevated pulmonary artery pressure is right ventricular hypertrophy and right heart failure.
The diagnosis of PPH should be considered in patients with unexplained progressive shortness of breath. In addition to fatigue, ankle swelling, syncope, chest pain and haemoptysis may all be presenting symptoms of pulmonary hypertension.
Supporting examination features are signs of right heart failure, notably peripheral oedema, hepatomegaly, tricuspid regurgitation, a loud pulmonary second heart sound and a raised jugular venous pressure.
Dr Morris is a GP in Shrewsbury, Shropshire.