PURPOSE: We investigated the qualitative components of dyspnea in cardiopulmonary diseases, and their relevance for clinical diagnosis.
METHODS: A respiratory symptom checklist (Han et al. Chest 2005;127:1942-51) was administered to 396 patients with dyspnea due to asthma (n = 65), COPD (n = 58), diffuse parenchymal lung disease (n = 53), pulmonary vascular disease (n = 53), primary cardiac disease with congestive heart failure (n = 62), and medically unexplained dyspnea (n = 105). Symptom factors measuring different qualitative components of dyspnea were derived by a principal component analysis. The separation of patient groups in terms of symptom factors was achieved by a variance analysis.
RESULTS: Seven symptom factors measured three dimensions of dyspnea: sensory qualities (difficulty breathing and phase of respiration, depth and frequency of breathing, urge to breathe, wheeze), affective aspects (chest tightness, anxiety), and behavioral impact (refraining from physical activity). A variance analysis with Duncan grouping showed that these factors separated clearly different types of patients with dyspnea. Difficulty breathing and phase of respiration occurred more often in patients with COPD and asthma, with the highest mean score in COPD (R2 = 0.12). Urge to breathe was unique for patients with medically unexplained dyspnea, and clearly distinguished those patients from other patient groups (R2 = 0.12). Wheeze showed up most frequently in asthma, followed by COPD and congestive heart failure (R2 = 0.17). Chest tightness was primarily linked to the diagnosis of medically unexplained dyspnea and, to a lesser extent, to asthma (R2 = 0.04). Anxiety characterized patients with medically unexplained dyspnea (R2 = 0.08). Refraining from physical activity appeared more often in congestive heart failure, pulmonary vascular disease, and COPD (R2 = 0.15).
CONCLUSION: Three dimensions of dyspnea were found in patients with cardiopulmonary diseases and these dimensions allowed separation of different types of patients.
CLINICAL IMPLICATIONS: The multiple dimensions of dyspnea may potentially have a role in diagnosis and differential diagnosis of dyspnea.
DISCLOSURE: Jiangna Han, No Financial Disclosure Information; No Product/Research Disclosure Information