title: Heart sounds are altered by open cardiac surgery.
abstract: OBJECTIVE
  Patients have reported that they perceive their own heart sounds differently after open cardiac surgery than before the surgery. The present study was designed to investigate whether changes in heart sounds can be quantitatively measured.
  
  
  METHODS
  Heart sounds were recorded from 57 patients undergoing coronary artery bypass graft (CABG) surgery and from a control group of 10 subjects. The so-called Hjorth descriptors and the main frequency peak were compared before and after surgery to determine whether the characteristics of the heart sounds had changed.
  
  
  RESULTS
  At a group level, the first heart sound was found to be significantly different after CABG surgery. Generally, the heart sounds shifted toward a lower frequency after surgery in the CABG group. No significant changes were found in the control group.
  
  
  CONCLUSIONS
  Heart sounds are altered after CABG surgery. The changes are objectively quantifiable and may also be subjectively perceived by the patients.
authors.affiliation: School of Health and Medical Sciences/Clinical Medicine, Orebro University, Orebro;
authors.forename: Anita
authors.initials: A
authors.lastname: Hurtig-Wennlöf
authors.forename: Christer
authors.initials: C
authors.lastname: Ahlstrom
authors.forename: Rigmor
authors.initials: R
authors.lastname: Egerlid
authors.forename: Marie
authors.initials: M
authors.lastname: Resare
authors.forename: Per
authors.initials: P
authors.lastname: Ask
authors.forename: Peter
authors.initials: P
authors.lastname: Rask
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