Paroxysmal dyspnoea

In mitral stenosis, paroxysmal dyspnoea may be precipitated by tachycardia secondary to emotion or exertion and is particulary liable to occur during pregnancy. The distinction between bronchial and cardiac asthma may occasionally be difficult. A long history of similar attacks, a personal or family history of allergic disorders, extreme expiratory difficulty, the tendency to occur in younger people and the absence of signs of heart disease are features of the former. Cough may result from pulmonary congestion or oedema, from superimposed infection or occasionally from pulmonary infarction. It is frequently troublesome at night and may be responsible for insomnia. Pulmonary congestion from cardiac failure may mimic chronic bronchitis in elderly persons.