Author Proof 10.1586/ERS.12.67 1 ISSN 1747-6348 © 2012 Expert Reviews Ltd www.expert-reviews.com Review Definition & use of term cardiac asthma James Hope was the first to publish the term ‘cardiac asthma’ in 1832. He distinguished among several variants of asthma and described the symptoms that differentiated asthma related to diseases of the heart from those caused by diseases of the lungs [1] . Osler, describing cardiac asthma in 1897, wrote “In cases of advanced arteriosclerosis there are often attacks of dysp- nea of great intensity recurring in spasms, often nocturnal. The patient goes to bed feeling quite well, and in the early morning hours wakes in an attack which in its abruptness of onset and general features, resembles asthma” [2] . Kahn (1927) described two distinct forms of cardiac dyspnea. One “depends upon the stasis in the pulmonary circulation associated with right ventricular deficiency”, which he called pulmo- nary asthma; the other “depends on deficiency of the left ventricle alone, with irritability of the respiratory center producing attacks of parox- ysmal dyspnea or cardiac asthma” [3] . In 1951, Lombardo and Harrison defined cardiac asthma as a syndrome induced by acute passive conges- tion and edema of the lungs occurring when the left side of the heart “suffers from a sud- den disproportion between work load and work capacity” [4] . These venerable descriptions of cardiac asthma are not far removed from the current view of cardiac asthma as wheezing, coughing and orthopnea due to congestive heart failure and not to primary pulmonary disease. A com- monly held view is that it is hemodynamic in origin and a consequence of pulmonary and bronchial venous hypertension. Prevalence of cardiac asthma It has been reported that the prevalence of all asthma in persons over the age 65 years is between 6.5 [5] and 10.4% [6] , consistent with the 8% prevalence among those enrolled in the large Cardiovascular Health Study [7] . This is also consistent with the 7.5% prevalence in those over the age of 65 years in data from the National Health Interview Survey, National Center for Health Statistics, CDC [201] . However among the elderly who have conges- tive heart failure, wheezing consistent with the syndrome of cardiac asthma is present in 35% of these patients [8] . This is more than 3.5-times greater than the reported prevalence of asthma in the elderly. It is likely that most or all of the excess asthma diagnoses represent cases of cardiac asthma. Pathophysiology of the effect of heart failure on airways Nocturnal attacks of coughing, wheezing and dyspnea are common in patients with impaired left ventricular function. While the mechanisms responsible for this remain obscure, several processes have been investigated that could contribute to cardiac asthma. Tsuyoshi Tanabe, Henry J Rozycki, Soichiro Kanoh and Bruce K Rubin* Department of Pediatrics, Virginia Commonwealth University School of Medicine and the Children’s Hospital of Richmond at VCU, Richmond, VA, USA *Author for correspondence: Tel.: +1 804 828 9602 brubin@vcu.edu Cardiac asthma has been defined as wheezing, coughing and orthopnea due to congestive heart failure. The clinical distinction between bronchial asthma and cardiac asthma can be straight forward, except in patients with chronic lung disease coexisting with left heart disease. Pulmonary edema and pulmonary vascular congestion have been thought to be the primary causes of cardiac asthma but most patients have a poor response to diuretics. There appears to be limited effectiveness of classical asthma medications like bronchodilators or corticosteroids in treating cardiac asthma. Evidence suggests that circulating inflammatory factors and tissue growth factors also lead to airway obstruction suggesting the possibility of developing novel therapies. Cardiac asthma: new insights into an old disease Expert Rev. Respir. Med. 6(6), 00–00 (2012) KEYWORDS: airflow obstruction • airway inflammation • heart failure • pulmonary edema • remodeling heart • squamous metaplasia • systemic inflammation • TGF-b