• Overview
• Inside the Heart
• Inside the Lungs
• Classification (WHO)
• Pulmonary Arterial Hypertension (PAH)
• Children with pulmonary hypertension
• Contraception and pregnancy
• Clinical Presentation

OVERVIEW

Pulmonary Hypertension

It is defined as a mean pulmonary artery pressure >25mmHG at rest and 30mmHG with exercise. This is a rare but progressive, debilitating disease that severely compromises the quality of life of the sufferer. This abnormally high pressure is associated with changes in the small blood vessels in the lungs.
Progressive narrowing of the vessels on the arterial side of the pulmonary circulation, resulting in elevated pulmonary artery pressure and pulmonary vascular resistance, which will eventually result in right heart failure.

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INSIDE THE HEART:
The pressure in the left side of the heart is normally much higher than the right side, however when the pressure increases in the right ventricle as a result of pulmonary hypertension, it is unable to deal with the extra workload and progressively dilates and ultimately fails.

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INDIDE THE LUNGS :
The pulmonary artery is a large blood vessel that transports oxygen poor blood from the right side of the heart to the lungs.
Most cases of pulmonary hypertension affect the hundreds of tiny blood vessels that branch from the main pulmonary artery, each of which is about the size of a human hair. Extra tissue growth occurs causing progressive narrowing of the lumen of these arteries.

The extra tissue growth is typically stiff and makes the blood vessels less able to expand, obstructing blood flow to the lungs. The right side of the heart now has to increase its pumping action in order to force blood through smaller than normal openings in the pulmonary arteries.

The result is a build up of pressure on the right ventricle, whichattempts to overcome the resistance, and in doing so weakens and dilates.

The right ventricle was not designed to cope with such high pressures and becomes so stretched that it cannot contract effectively, resulting in failure of the right heart.

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Classification of Pulmonary Hypertension according to the World Health Organisation 1998

For more Information please refer to: A New Classification of Pulmonary Hypertension (Stuart Rich, MD Professor of Medicine Rush Medical College)

In 1998, the world health organisation sponsored a meeting of pulmonary hypertension specialists from around the world, resulting in a new classification of the disease in to a treatment-based system.

1. Pulmonary Arterial Hypertension:
Primary Pulmonary Hypertension
Sporadic
Familial

Pulmonary Arterial Hypertension

Related to :
Collagen Vascular Disease
Congenital Systemic to Pulmonary Shunts
Portal Hypertension
HIV infection
Drugs/ toxins
Anorexigens (aminorex,fenfluramine,dexfenfluramine)
Definite toxic Rapeseed oil
Very likely:Amphetamines, L-tryptophan
Possible:meta-amphetamins, cocaine, chemotherapeutic agents
Persistant Pulmonary Hypertension of the newborn
Others

3. Pulmonary Hypertension associated with disorders of the Respiratory System and/ or hypoxaemia:
Chronic obstructive lung disease
Interstital lung disease
Sleep disordered breathing
Alveolar Hypoventilation disorders
Chronic exposure to high altitude
Neonatal lung disease
Alveolar capillary dysplasia
Others

4. Pulmonary Hypertension caused by chronic thrombotic and /or embolic disease
Thromboembolic obstruction of Proximal Pulmonary arteries
Obstruction of distal; pulmonary arteries

Pulmonary embolism:
Thrombus, tumour, ova, parasites, foreign material
Insitu thrombus
Sickle cell disease

5. Pulmonary Hypertension associated with miscellaneous disease:

Inflammatory

Schistosomiasis
Sarcoidosis
Others

Extrinsic compression of the central pulmonary
veins

Fibrosing mediastinitis
Adernopathy/Tumours

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Pulmonary arterial Hypertension (PAH)
Pulmonary arterial Hypertension (PAH) is categorised as either Primary pulmonary hypertension (PPH) or secondary to another condition.

Primary
Primary pulmonary Hypertension (PPH) refers to pulmonary hypertension for which no cause can be identified .It occurs at random and is a rapidly progressive disease with a published incidence of 2 per (4) million per annum. Patients with PPH are sub categorised into sporadic and familial.

The diagnosis of familial PPH is made through a patient's family history, as there are no clinical or pathologic features that separate these two entities. Although the prevalence of familial PPH has been published as being 12% at the time of the NIH registry, this underestimates the true familial prevalence. Because of incomplete penetrance of the gene, it may skip a generation, which would not be uncovered unless the physician was to take a deep look at the patient's family medical histories.

PPH is thought to be more common in women -mid thirties, if untreated is documented as having a median life expectancy of 2.8 years from diagnosis with the majority of patients dying within 5 years.

Secondary
Pulmonary Arterial Hypertension (PAH)

• This form of pulmonary hypertension is secondary to an underlying disease process.
• The incidence of PAH is published as being a further 1-2 per million per annum.
• The rapidity in which symptoms occur is highly variable and is often related to the age of onset and associated conditions.

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Children with pulmonary hypertension:
The diagnostic workup of a child with pulmonary arterial hypertension is similar to that of an adult, although other more common causes of pulmonary hypertension in childhood must be excluded. These include congenital heart disease and persistent pulmonary hypertension of the newborn, which has not regressed satisfactorily. Children can be extremely ill at presentation having deteriorated swiftly, but the principals of management are the same in children and adults.

Choice of therapy is based on the findings at cardiac catheterisation and the response to acute vasodilator testing, which includes the study with nitric oxide. Greater reactivity is expected in children, based on both pathological and clinical data. Hence more children than adults can be treated with oral vasodilator therapy.

Children who do not respond to acute vasodilator testing are treated with continuous intravenous epoprostenol, even in early childhood. Children as young as 8 years have been treated with the subcutaneous prostacyclin analogue UT-15, but pain at the injection site is a limiting factor.

Atrial septostomy can be carried out at the time of a diagnostic catheter, particularly if there is a history or suspicion of drop attacks. All require warfarin, some need diuretics, and domiciliary oxygen is helpful. Family members are screened and genetic counselling is often requested.

Contraception and pregnancy
Pregnancy is poorly tolerated and fatalities can occur both during pregnancy and in the post partum period. Combined oral contraceptives increase the risk of venous thromboembolism ans are contraindicated in pulmonary hypertension. Data on the risks associated with progestogen only pills are limited although they may be safer.

Recommendations
Women of childbearing age with pulmonary hypertension require contraceptive advice. They should be advised against becoming pregnant. Very low oestrogen or progestogen pills may be used but their safety is unproven. Pregnancy is contraindicated on Tracleer(Bosentan)therapy. Pregnancy serum and urine testing must be carried out prior to treatment iniation. Hormonal contraception, including oral, injectable and implantable contraceptives should not be used as a sole means of contraception because these may not be effective in patients receiving Tracleer(Bosentan) therapy.

Women of childbearing potential should have serum /urine pregnancy testing carried out on a monthly basis. The patient must be advised that any delay in menses or any other reason to suspect pregnancy, she must notify the physician immediately for pregnancy testing. If the pregnancy test is positive, the physician and patient must discuss the risk to the pregnancy and to the foetus.

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Clinical Presentation

Pulmonary Hypertension is often not diagnosed in a timely manner because its early symptoms can be confused with those of other cardio respiratory conditions, Symptoms can initially be subtle and relatively non-specific. A process of exclusion generally makes diagnosis of PH by looking for and ruling out other diseases. This has been reported to take up to 18 months.

• Shortness of breath (Dyspnoea) with no obvious cause following exertion or at rest.
• Excessive fatigue
• Dizziness especially on climbing stairs or standing up
• Fainting (Syncope), weakness upon physical exertion
• Chest pain especially during physical activity
• Palpations
• Swollen legs and ankles
• Cough
• Haemoptysis

As the Right heart continues to fail-symptom severity increases

• Worsening Fatigue
• Marked ankle oedema
• Throbbing sensation felt in the neck
• Feeling of fullness in the abdomen (Ascites)
• Orthnopea
• PND (Paroxysmal Nocturnal Dyspnoea)
• The liver may become tender
• Lips and fingernails may take on a bluish tint (Cyanosis)
• If oxygen levels are low a long time,fingernails may form a small bulge at the end (Clubbing)
  
  

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