Characterization and Triggers of Dyspnea in Patients with Chronic Obstructive Pulmonary Disease or Chronic Heart Failure: Effects of Weather and Environment.

BACKGROUND AND OBJECTIVES: Dyspnea is one of the most disturbing symptoms for patients with chronic obstructive pulmonary disease (COPD) or heart failure (HF). This study investigated dyspnea triggers and factors associated with worsening dyspnea in patients with COPD or HF.
METHODS: COPD support group members and HF patients with reduced ejection fraction (HFrEF) and no airway obstruction answered a questionnaire describing different weather conditions (rising/falling air pressure, sunny, foggy, rainy, windy, snowy, hazy, high ozone levels, and airborne pollen) and environmental circumstances (cooking, grilling, perfumes, cigarette smoke, gasoline odor, and flower scents) and were asked to estimate the occurrence and severity of dyspnea under these conditions using predefined scales.
RESULTS: 230 patients with COPD and 90 with HFrEF (left ventricular ejection fraction 34 ± 10%, Tiffeneau index > 70%) were analyzed. COPD patients reported dyspnea more often than HF patients in almost all weather and environmental conditions (p = 0.004 to p < 0.001), with the exception of outdoor floral scents and cigarette smoke. Severe to very severe dyspnea was reported more in COPD versus HF in all weather and environmental conditions except sunny weather (p = 0.01 to p < 0.001). COPD was associated with more severe dyspnea than HF in all conditions (all p < 0.001).
CONCLUSIONS: Dyspnea was triggered by a variety of weather and other environmental triggers in patients with COPD and occurred more often than in HF patients under the same conditions. Foggy weather and exposure to perfumes were associated with severe dyspnea in the majority of COPD patients, but only a minority of HF patients.