Computerized lung sound analysis following clinical improvement of pulmonary edema due to congestive heart failure exacerbations

Background Although acute congestive heart failure (CHF) patients typically present with abnormal auscultatory findings on lung examination, lung sounds are not normally subjected to rigorous analysis. The goals of this study were to use a computerized analytic acoustic tool to evaluate lung sound patterns in CHF patients during acute exacerbation and after clinical improvement and to compare CHF profiles with those of normal individuals.Methods Lung sounds throughout the respiratory cycle was captured using a computerized acoustic-based imaging technique. Thirty-two consecutive CHF patients were imaged at the time of presentation to the emergency department and after clinical improvement. Digital images were created, geographical area of the images and lung sound patterns were quantitatively analyzed.Results The geographical areas of the vibration energy image of acute CHF patients without and with radiographically evident pulmonary edema were (67.9±4.7) and (60.3±3.5) kilo-pixels, respectively (P <0.05). In CHF patients without and with radiographically evident pulmonary edema (REPE), after clinical improvement the geographical area of vibration energy image of lung sound increased to (74.5±4.4) and (73.9±3.9) kilo-pixels (P <0.05), respectively. Vibration energy decreased in CHF patients with REPE following clinical improvement by an average of (85±19)% (P <0.01). Conclusions With clinical improvement of acute CHF exacerbations, there was more homogenous distribution of lung vibration energy, as demonstrated by the increased geographical area of the vibration energy image. Lung sound analysis may be useful to track in acute CHF exacerbations.