title: Evaluation of non-ST segment elevation acute chest pain syndromes with a novel low-profile continuous imaging ultrasound transducer.
abstract: BACKGROUND
  This investigation was designed to test the hypothesis that continuous cardiac imaging using an ultrasound transducer developed in our laboratory (ContiScan) is superior to electrocardiogram (ECG) monitoring in the diagnosis of coronary artery disease (CAD) in patients with acute non-ST segment elevation chest pain syndromes.
  
  
  METHODS
  Seventy patients with intermediate to high probability of CAD who presented with typical anginal chest pain and no evidence of ST segment elevation on the ECG were studied. The 2.5-MHz transducer is spherical in its distal part mounted in an external housing to permit steering in 360 degrees. The transducer was placed at the left sternal border to image the left ventricular short-axis view and recorded on video tape at baseline, during and after episodes of chest pain. Two ECG leads were continuously monitored. The presence of CAD was confirmed by coronary arteriography or nuclear or echocardiographic stress testing.
  
  
  RESULTS
  Twenty-four patients had regional wall motion abnormalities (RWMA) on their initial echo which were unchanged during the period of monitoring. All had evidence of CAD. Twenty-eight patients had transient RWMA. All had evidence of CAD. Eighteen patients had normal wall motion throughout the monitoring period, 14 of these had no evidence of CAD, and four had evidence of CAD. These four patients did not have chest pain during monitoring. The sensitivity, specificity, and accuracy of echocardiographic monitoring for diagnosing non-ST elevation myocardial infarction was 88%, 100%, and 91% respectively. The sensitivity, specificity, and accuracy of the ECG for diagnosis of CAD were 31%, 100%, and 52%, respectively. Echocardiography was superior to ECG (P < 0.001).
  
  
  CONCLUSIONS
  The data indicate that continuous cardiac imaging is superior to ECG monitoring for the diagnosis of CAD in patients presenting with acute non-ST segment elevation chest pain syndromes. This technique could be a useful adjunct to ECG monitoring for myocardial ischemia in the acute care setting.
authors.affiliation: Division of Cardiology, Long Beach VA Medical Center, UC Irvine School of Medicine, Irvine, California, USA. dmohar@uci.edu
authors.forename: P Anthony N
authors.initials: PA
authors.lastname: Chandraratna
authors.forename: Dilbahar S
authors.initials: DS
authors.lastname: Mohar
authors.forename: Peter F
authors.initials: PF
authors.lastname: Sidarous
authors.forename: Prabhjyot
authors.initials: P
authors.lastname: Brar
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Miller
authors.forename: Nissar
authors.initials: N
authors.lastname: Shah
authors.forename: John
authors.initials: J
authors.lastname: Kadis
authors.forename: Ashgar
authors.initials: A
authors.lastname: Ali
authors.forename: Prabhsimran
authors.initials: P
authors.lastname: Mohar
mesh_terms: D056586:Acute Chest Syndrome / Q000000981:diagnostic imaging*; D000368:Aged; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014463:Ultrasonography