title: Evaluation of signal-averaged cardiokymography for the detection of ischaemic left ventricular dysfunction.
abstract: Cardiokymography (CKG) is a non-invasive method for the detection of patients with coronary artery disease (CAD). Issues of the present study were to evaluate the feasibility, sensitivity and specificity of a recently developed signal-averaged CKG system for detecting patients with pharmacologically induced ischaemic left ventricular wall motion abnormalities (WMA) during pharmacologic stress echocardiography (SE). Precordial CKG curves were recorded in 100 consecutive patients who underwent dobutamine-SE for suspected CAD. For interpretation, CKG curves were classified into three different types, depending on the degree of systolic outward motion. CKG test results were regarded as positive (indicating myocardial ischaemia) if there was a change of the baseline CKG type at peak pharmacologic stress. The CKG test results were positive in 18 of 27 patients with a pathologic dobutamine-SE (sensitivity 67%), but did not show any change of the prior CKG type in 57 of 69 patients with a normal SE (specificity 83%). Patients with a true positive CKG test had significantly (P<0.05) more echocardiographic segments with WMA than patients with a false negative CKG test.
  
  
  CONCLUSIONS
  Signal-averaged CKG can detect patients with ischaemic ventricular dysfunction. Sensitivity of CKG in detecting patients with WMA depends on the extent of left ventricular ischaemia. Further studies are needed to define the diagnostic value of signal-averaged CKG in the non-invasive detection of patients with suspected CAD.
authors.affiliation: I. Medical Clinic, Faculty for Clinical Medicine Mannheim, University of Heidelberg, Germany.
authors.forename: A W
authors.initials: AW
authors.lastname: Scherhag
authors.forename: S
authors.initials: S
authors.lastname: Pfleger
authors.forename: C
authors.initials: C
authors.lastname: Ceconi
authors.forename: W
authors.initials: W
authors.lastname: Voelker
authors.forename: J
authors.initials: J
authors.lastname: Gehring
authors.forename: U
authors.initials: U
authors.lastname: Staedt
authors.forename: D L
authors.initials: DL
authors.lastname: Heene
mesh_terms: D000328:Adult; D000368:Aged; D002316:Cardiotonic Agents; D004280:Dobutamine; D004452:Echocardiography; D004562:Electrocardiography / Q000379:methods; D004571:Electrokymography / Q000379:methods*; D005069:Evaluation Studies as Topic; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D012146:Rest / Q000502:physiology; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine