Noninvasive detection of anterior wall asynergies by cardiokymography compared to electrocardiography.

In order to determine the value of cardiokymography in detecting left ventricular (LV) anterior wall asynergies, 80 consecutive patients had a cardiokymogram (CKG) and an electrocardiogram (ECG) on the day prior to coronary angiography. Technically adequate CKGs were obtained in 72 patients (67 men and 5 women, mean age 53 +/- 6.5 years). For validation of regional contraction abnormalities, quantitative LV angiography was used. Stepwise linear discriminant analysis was applied to investigate the diagnostic power of CKG. Sensitivity of the CKG for LV anterior wall asynergy was 67.9% (ECG: 39.6%) and specificity was 68.4% (ECG: 94.7%) on the basis of 1 SD of the mean values of the radial axis shortening of a control group. For 2 SD, the sensitivity was 65.6% (ECG: 56.3%) and the specificity 47.5% (ECG: 90%). By combined testing, the specificity increased to 98.3%, whereas the sensitivity dropped to 26.9%. The improvement of the post-test likelihood for a positive ECG by a positive CKG is especially pronounced in the intermediate prevalence range, whereas for a negative ECG the post-test likelihood can be further decreased by a negative CKG in the intermediate and high prevalence range. The ECG as a single test seems to be the more appropriate noninvasive method for detecting LV anterior wall asynergies; however, the combined use of both ECG and CKG may considerably improve the diagnostic accuracy.