The resting cardiokymogram: distribution of morphologies in normal patients and in patients with coronary heart disease

Evaluation of signal-averaged cardiokymography for the detection of ischaemic left ventricular dysfunction

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.

Cardiokymographic wall motion pattern in patients with acute myocardial infarction

We studied 50 patients with acute myocardial infarction by cardiokymography to record anterior left ventricular wall motion. Systolic outward motion was observed in 46 of 50 patients (92%). Holosystolic outward motion was characteristic of acute anterior infarction (93%) and acute subendocardial infarction (89%) but was less common in acute inferior infarction (29%). Partial systolic outward motion was seen in 8 of the 14 patients with acute inferior infarction, but only in 2 of 36 patients with acute anterior and subendocardial infarction. Cardiokymographic abnormalities were seen in more precordial locations in acute anterior (80%) and subendocardial infarction (97%) than in inferior infarction (74%). Holosystolic outward motion was seen in 75% of all locations in acute anterior and subendocardial infarction and only in 23% in acute inferior infarction. Thus both the extent and the severity of abnormal systolic outward motion clearly separated inferior infarction from anterior and subendocardial infarction. Dynamic changes in wall motion contraction patterns were observed during the course of acute myocardial infarction; both improvement and deterioration were observed. Cardiokymography is a simple, non-invasive method to assess changes in left ventricular segmental wall motion in patients with acute myocardial infarction.