From the Guidelines
Cardiac asthma, also known as acute pulmonary edema, is a condition characterized by wheezing, coughing, and difficulty breathing due to fluid buildup in the lungs resulting from left-sided heart failure, and its treatment focuses on managing the underlying heart condition rather than asthma symptoms. The key features of cardiac asthma include:
- Symptoms worsen when lying flat
- Often occurs at night
- Associated with other heart failure symptoms like swelling in legs and fatigue
- Responds to heart failure treatment rather than asthma medications, as noted in the context of distinguishing cardiac from pulmonary dyspnea, where the most useful studies include B-natriuretic peptide measurement, echocardiography, and, if needed, a cardiopulmonary exercise test 1. Treatment of cardiac asthma typically includes:
- Diuretics (e.g., furosemide 20-80 mg daily) to reduce fluid buildup
- ACE inhibitors or ARBs to improve heart function
- Beta-blockers to reduce heart workload
- Lifestyle changes like reducing salt intake and fluid restriction, which can help alleviate symptoms and improve quality of life, as seen in patients with congestive heart failure who present with dyspnea on exertion 1. It's crucial to distinguish cardiac asthma from bronchial asthma, as the treatments differ significantly, and misdiagnosis can lead to ineffective treatment and worsening of the underlying heart condition, highlighting the importance of proper diagnosis and management, as suggested by the need to refer to appropriate specialists (eg, cardiologist or pulmonologist) to perform cardiopulmonary testing when breathlessness with exercise, with or without chest pain, might be caused by heart disease or other conditions in the absence of EIB 1.
From the Research
Definition and Pathophysiology
- Cardiac asthma, also known as acute pulmonary edema, is characterized by episodes of cough, dyspnea, and wheezing caused by left ventricular dysfunction 2.
- The symptoms of cardiac asthma are similar to those of bronchial asthma, including cough, dyspnea, and wheezing, but the pathophysiology is different 2, 3.
- Pulmonary edema and pulmonary vascular congestion are thought to be the primary causes of cardiac asthma, but the response to diuretics is often poor 3.
- Circulating inflammatory factors and tissue growth factors may also contribute to airway obstruction in cardiac asthma 3.
Clinical Presentation and Diagnosis
- Cardiac asthma can be difficult to distinguish from bronchial asthma, especially in patients with chronic lung disease and left heart disease 3, 4.
- The clinical presentation of cardiac asthma includes wheezing, coughing, and orthopnea due to congestive heart failure 3.
- Patients with cardiac asthma may have a poor response to classical asthma medications like bronchodilators or corticosteroids 3.
- Cardiac echocardiography and natriuretic peptides levels can be used to confirm congestive heart failure and diagnose cardiac asthma 5.
Epidemiology and Outcomes
- Cardiac asthma is common in elderly patients, representing one third of congestive heart failure cases 5.
- Patients with cardiac asthma tend to have more distal airway obstruction and are more hypercapnic than those with classical congestive heart failure 5.
- The in-hospital and one-year mortality rates for cardiac asthma are similar to those for classical congestive heart failure 5.