RESUMEN
BACKGROUND: The incidence of acute heart failure (AHF) increases in cold weather. Whether or not AHF has seasonal variation in Korea is unclear, and the influence of humidity on AHF incidence is also unclear. The aim of this study was to examine the correlation between the number of daily emergency department (ED) visits for AHF and the temperature and humidity in Korea. METHODS: On a retrospective basis, we investigated the medical records of patients who visited the ED with dyspnea from Jan. 1, 2008 to Dec. 31, 2010. Inclusion criteria comprised both evidence of clinical symptoms and the presence of signs of pulmonary congestion on chest X-rays. Exclusion criteria included a medical history showing end-stage renal disease with dialysis or showing an acute ST elevation myocardial infarction. The number of daily ED visits for AHF was compared with meteorological data after stratifying temperature or humidity into 3 parts. RESULTS: After stratification by humidity, the results revealed that the number of daily ED visits was significantly associated with minimum temperatures occurring one to 2 days prior to ED admission, although only in the lowest tertile of humidity (p = 0.012, p = 0.021, respectively). The relationship between humidity and daily ED visits for AHF was the same as that mentioned above (p = 0.016, p = 0.039, respectively). CONCLUSIONS: The number of patients with AHF in Korea increases in cold weather, as is the case in other countries. Specifically, AHF incidence was related to temperature minimums occurring one to 2 days prior to ED admission, as well as with humidity.