Pulmonary Hypertension Unit

Investigations

Chest radiography

chest

CT of thorax

These are computerised x-ray techniques that show more detail of the lung parenchyma. (tissue)

Electro cardiogram (ECG)

electroIt is a record of the electrical activity produced by the heart. This is one of the first tests performed on a potential PH patient. The result may indicate that the right side of the heart is thickened, due to unusual stress or high pressure, but an ECG cannot, by itself, diagnose PH.

Holter monitor – You may be fitted with a Holter monitor (a portable ECG device) to wear for a period of 24-48 hours. This will record heart rate and rhythm and highlight any changes in response to activity, exercise.

Blood testing

Blood samples will be obtained to assess kidney, liver thyroid function and to out rule the possibility of an underlying connective tissue disease

Six minute walk or shuttle test

This is a good indicator of your exercise capability. The distance walked and accompanying symptoms will be noted

Pulmonary function testing

blowUsed to assess lung volumes and determine any obstruction to airflow or restriction in lung capacity. You will be asked to blow in to a mouthpiece while your nose is pinched closed

Echocardiogram

echo2This procedure is painless and risk free, and is used both to make a preliminary diagnosis and later to monitor a patient’s condition. It involves the patient lying on their side while a transducer is pressed against your chest in order to capture moving images of the heart on a TV screen. The images permit the doctor to measure the size of the heart and the thickness of the heart muscle, heart valves, blood flow and an estimation of pressures in the specific chambers can be observed

Ventilation – Perfusion lung Scan

This can be performed on an outpatient basis. A radioactive dye is injected in to a peripheral vein. Immediately after the injection, the lungs are scanned for radioactivity. The dye will highlight any areas where blood perfusion is reduced possibly indicating the presence of clots. Similarly a radioactive gas is inhaled to evaluate lung ventilation and compared with lung perfusion.

Angiogram

angiogramThis procedure is usually carried out at the time of the right heart catheterisation. Contrast dye is injected through very fine catheter in to the groin and x-rays taken as the contrast flows through the pulmonary arteries; any occlusion due to the presence of clots will be highlighted. Heart pressures are also calculated at this point.

Right heart catherisation

This procedure is the most accurate and conclusive of diagnostic tools, when seeking confirmation of pulmonary hypertension. A thin flexible tube with a small inflatable balloon on the tip (a swan ganz catheter) is inserted through a neck or groin vein, and threaded all the way to the right side of the heart, into the pulmonary artery, where pressures are recorded.

Right heart catheterisation is essential in determining initial and subsequent therapy. This, together with NYHA Classification, echocardiograph data and 6-minute walk exercise testing are used in treatment decisions.

Acute vasoreactivity study

The rationale for vasodilators is based on the importance of vasoconstriction in the pathogenesis of pulmonary hypertension.
The initial response to acute vasodilator testing accurately identifies patients who may respond to long-term oral vasodilator treatment.

This vasodilator study will be undertaken as part of the right heart catheterisation since invasive monitoring is required.
The haemodynamic response to intravenous adenosine infusion, inhaled nitric oxide, and intravenous epoprostenol is recorded.
A positive response is present when there is a >20% reduction in mean pulmonary artery pressure or pulmonary vascular resistance, providing there is no fall in cardiac output. A negative response is recorded when there is no significant improvement or deterioration in pulmonary haemodynamics.