The Nature of Cardiac and of Pulmonary Dyspnea

Dyspnea has many characteristics, differing from one clinical state to another. In pulmonary diseases the immediate cause is usually a disproportion between actual ventilation (breathing requirement) and breathing capacity. The hyperventilation of organic pulmonary disease is often mistakenly diagnosed as psychoneurosis. In early cardiac dyspnea, muscular fatigue associated with inadequate cardiac output may be a factor. True pulmonary congestion becomes important in more advanced left ventricular failure.