This page contains a Flash digital edition of a book.
Differentiation


Figure 2: Indicators of pulmonary hypertension on computed tomography angiography. A: Pulmonary artery (PA) dilatation, as shown by a diameter exceeding the diameter of the ascending aorta (AO). B: Right ventricular hypertrophy (RVH).


into the European and North American guidelines for the diagnosis and treatment of PH. The WSPH has proposed a number of small changes to the existing algorithm,22 which is outlined in Figure 1. Awareness of the possibility of a diagnosis of PH is an important first step to assure timely treatment. The first clue towards a diagnosis of PH is usually found in a patient’s symptoms or signs during physical examination. Alternatively, the suspicion of PH arises with incidental findings on diagnostic tests or during specific screening efforts.


Symptoms and signs


An unexplained decrease in exercise tolerance is often the first symptom of the presence of PH. Unfortunately, this symptom is neither sensitive nor specific and frequently the diagnosis of PH is only suspected after symptoms of more severe PH and right heart failure develop, such as palpitations, chest pain, peripheral oedema and syncope. A physical examination may reveal signs of PH, forexample, a right parasternal heave, a loud second heart tone and a systolic murmur at the fourth left intercostal space due to tricuspid insufficiency.


10


Coincidental findings of diagnostic tests It is not uncommon for a diagnosis of PH to be unsuspected until a diagnostic test ordered for other purposes provides specific clues, such as right ventricular strain on the electrocardiogram, cardiac enlargement or


www.hospitalpharmacyeurope.com


Figure 3: Computed tomography (A) and conventional (B) pulmonary angiogram of a patient with chronic thromboembolic pulmonary hypertension. The arrows show near complete occlusions of the right middle and right lower lobe arteries. Figures reproduced with kind permission from Diagnosis and treatment of pulmonary hypertension. Vonk Noordegraaf A, Boonstra A, Konings TC, Marques KM, Bogaard HJ. Ned Tijdschr Geneeskd 2014;158:A7315.


pulmonary vessel dilatation on the chest X-ray or CT scan (see Figure 2), or signs of right ventricular pressure overload on the echocardiogram. The latter diagnostic modality allows an estimation of the right ventricular systolic pressure or may provide other hints at a diagnosis of PH, such as right ventricular hypertrophy and dilatation and paradoxical movement of the interventricular septum towards the left ventricle.


Screening of groups at increased risk Early recognition of symptoms increases the likelihood of an early diagnosis of PH in patients at risk of this condition. Systematical screening for PH adds to this approach in patients with systemic sclerosis, in which population the prevalence of PAH is about 9%.23,24


Capillaroscopy may be an


additional diagnostic modality that allows early recognition of PAH in this patient group.25


Whether systematic screening is


also of value in other populations at risk (for example, healthy carriers of BMPR-II mutations, who have a 30% lifetime risk of PAH development) remains to be determined.


When echocardiography confirms a diagnostic suspicion of PH, the next step is to confirm or exclude the presence of left heart disease and/or chronic lung disease. While pulmonary function testing and arterial blood gas analysis are essential to evaluate the existence of chronic lung disease, echocardiography may provide important clues towards a diagnosis of


systolic or diastolic left heart failure or valve abnormalities. Left heart failure can further be suggested by the medical history or by electrocardiographic signs of left atrial dilatation and left ventricular hypertrophy. Only when the echocardiogram provides insufficient explanation for the presence of PH, further diagnostic testing is warranted. When pulmonary or cardiac causes of PH are excluded, the next step in the diagnostic algorithm is ventilation/ perfusion scintigraphy. This test still has a higher sensitivity to detect CTEPH than CT angiography.26


An abnormal perfusion


scintigraphy warrants referral to an expert centre for (non-) surgical treatment of CTEPH, where usually a pulmonary angiography will be performed (see Figure 3). This procedure can be combined with a right heart catheterisation, which procedure will be performed without angiography when the ventilation/perfusion scintigram is normal.


During the right heart catheterisation, the pulmonary artery wedge pressure is determined by occluding a small pulmonary artery via inflation of the balloon at the tip of the Swan-Ganz catheter. Through the interruption of bloodflow, it is possible to estimate the left ventricular end-diastolic pressure. A pulmonary artery wedge pressure (PAWP) higher than 15mmHg indicates that left heart failure is the cause of the elevated pressure in the pulmonary artery, no matter the magnitude of the increase. A right heart catheterisation should include measurement of the cardiac


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44