title: Acoustic cardiography augments prolonged QRS duration for detecting left ventricular dysfunction.
abstract: BACKGROUND
  Prolonged QRS duration has been used as a marker for left ventricular (LV) systolic dysfunction (SD) and is used in the evaluation of patients presenting with known or suspected heart failure. The goal of this study was to compare the abilities of QRS duration and simultaneous digital ECG and heart sounds, that is acoustic cardiographic, parameters to identify patients with LV dysfunction.
  
  
  METHODS
  Our learning population consisted of 171 patients with possible chronic compensated or mildly decompensated heart failure who presented to an ambulatory cardiology clinic for echocardiographic examination. We defined LVSD as a LV ejection fraction < 50%, and estimated LV filling pressures from diastolic measurements. These patients also had acoustic cardiographic recordings from which we obtained a variety of individual ECG and acoustic cardiographic parameters. We used the product of four of these parameters to obtain a diagnostic score for LV dysfunction. We then compared the diagnostic performances of QRS duration and the score on a test population of patients who presented to an emergency department with possible heart failure.
  
  
  RESULTS
  In the learning population, the sensitivities/specificities of QRS duration > or =120 ms and the score for prediction of LVSD were 51%/92% and 77%/90%, respectively. In the test population, the score remained superior to QRS duration for detecting LVSD as well as acute decompensated heart failure.
  
  
  CONCLUSIONS
  Improved identification of LVSD and clinical heart failure can be achieved with a cost-effective bedside screening tool with the simple combination of simultaneously acquired digital ECG and heart sound data.
authors.affiliation: Cardiology Outpatient Clinic, Othmarsingen and Frauenfeld, Switzerland. Michel.Zuber@bluewin.ch
authors.forename: Michel
authors.initials: M
authors.lastname: Zuber
authors.forename: Christine H
authors.initials: CH
authors.lastname: Attenhofer Jost
authors.forename: Peter
authors.initials: P
authors.lastname: Kipfer
authors.forename: Sean P
authors.initials: SP
authors.lastname: Collins
authors.forename: Frank
authors.initials: F
authors.lastname: Michota
authors.forename: W Frank
authors.initials: WF
authors.lastname: Peacock
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology