Normal airway responsiveness to methacholine in cardiac asthma

Cardiac asthma has been used as a synonym for episodes of cough, dyspnea, and wheezing caused by left ventricular dysfunction. The similarity of the terms bronchial asthma and cardiac asthma, and the observed symptoms of each disease implies a common pathophysiology. Bronchial asthma is characterized pathologically by airway narrowing, inflammation, edema, and obstruction by mucus. Bronchial asthma is defined as increased responsiveness of the tracheobronchial tree, which is manifested clinically as reversible expiratory airflow obstruction. The classic symptoms of bronchial asthma are cough, dyspnea, and wheezing. Cardiac asthma produces the same symptoms, but the pathophysiology producing these symptoms is not well described. We describe two patients with cardiac asthma who failed to demonstrate airway hyperresponsiveness to nonspecific bronchoprovocation testing and we postulate that these patients' symptoms were produced exclusively by left ventricular failure.