Cor Pulmonale

Cor pulmonale is a disease in which there is a change in structure and function of the right ventricle of the heart as a result of a respiratory disorder. There are two types of cor pulmonale including Right ventricular hypertrophy or RVH which is the predominant change in chronic cor pulmonale and in acute cases dilation dominates. Both cases of hypertrophy and dilation are the result of increased right ventricular pressure.

Dilation is normally a stretching of the ventricle, and is the immediate result of increasing the pressure in an elastic container. On the other hand Ventricular hypertrophy is an adaptive response to a long-term increase in pressure. As a result additional muscle grows to allow for the increased contractile force required to move the blood against greater resistance.

It is essential for the disease to be classified as cor pulmonale, should originate in the pulmonary circulation system. Two major causes are vascular changes as a result of tissue damage and chronic hypoxic pulmonary vasoconstriction. Cor pulmonale is fatal to health and if left untreated, cor pulmonale can lead to right-heart failure and death.

Symptoms :
In most of the patients there are certain common symptoms that may suggest the presence of cor pulmonale in a patient with pulmonary or cardiopulmonary disease include:

• Worsening tachypnoea, particularly at rest
• Feeling fatigued and lassitude
• Edema or Ankle swelling
• A condition of worsening exertional dyspnoea with significant recent deterioration in exercise tolerance
• A case of worsening cough (particularly if non-productive)
• A feeling of Angina-type chest discomfort – often non-responsive to nitrates (thought to be due to right ventricular ischaemia or stretching of pulmonary artery during exertion)
• Haemoptysis (due to pulmonary arteriolar rupture or leakage)
• Hoarseness – occurs occasionally due to compression of the left recurrent laryngeal nerve by dilated pulmonary artery
• Exertional syncope – a late symptom indicating severe disease
• Late-stage hepatic congestion can cause anorexia, jaundice and right-upper-quadrant abdominal discomfort.

Causes :
The disease is associated with almost any chronic lung disease or condition causing prolonged low blood oxygen can lead to cor pulmonale. A few of these causes include:

• Chronic obstructive pulmonary disease (COPD)
• Obstructive sleep apnea
• Central sleep apnea
• Mountain sickness
• Cystic fibrosis
• Primary pulmonary hypertension
• Pneumoconiosis
• Kyphoscoliosis
• Interstitial lung disease
• Chronic thromboembolic pulmonary disease
• Pulmonary vascular disease
• Pulmonary hypertension

Treatment :
Acute cor pulmonale is treated by trying to rapidly correct the underlying precipitant which is often acute pulmonary embolism or an infective exacerbation of COPD. Similarly, in chronic cor pulmonale, treatment of the underlying cause is combined with specific management as below:

• Long term Oxygen therapy
• Diuretics
• Vasodilators
• In many cases, Inotropic drugs, particularly digoxin, are frequently used but there is little evidence for their efficacy in right heart failure, in contrast to their use with left ventricular failure.