Dobutamine stress magnetocardiography for the detection of significant coronary artery stenoses - a prospective study in comparison with simultaneous 12-lead electrocardiography.
BACKGROUND
Exercise electrocardiography is an imperfect test for the detection of coronary artery disease (CAD). Magnetocardiography detects cardiac electrical disturbances associated with myocardial ischemia. We prospectively investigated the accuracy of high-dose dobutamine stress magnetocardiography (DS-MCG) and simultaneous electrocardiography (DS-ECG) for the detection of significant CAD.


METHODS
100 patients with an intermediate pre-test probability for CAD underwent DS-MCG using a multichannel magnetometer prior to invasive coronary angiography. Patients were examined at rest and during a standard dobutamine-atropine scheme. Significant reduction of epicardial current strength/density during stress, reconstructed from the magnetic field map and superposed on a virtual heart model indicates myocardial ischemia. A 12-lead DS-ECG was recorded simultaneously. Significant coronary artery stenosis was defined as > or = 70% of lumen reduction.


RESULTS
Without beta-blocker all 100 patients reached the targeted heart rate. The image quality of DS-MCG and DS-ECG was sufficient for analysis in all patients. In 19 patients CAD was ruled out angiographically. Thirty two or seven patients revealed coronary artery stenoses of 30-49% or of 50-69%, respectively. In 42 patients we found significant stenoses of > or = 70%. In 41 of these patients DS-MCG revealed myocardial ischemia. The sensitivity of DS-MCG and DS-ECG for the detection of significant coronary artery stenosis was 97.6% and 26.2%, the specificity of DS-MCG and DS-ECG 82.8% and 82.8%, respectively.


CONCLUSIONS
DS-MCG can be performed with a standard dobutamine/atropine stress protocol. DS-MCG yields a significantly higher accuracy for the detection of significant coronary artery stenosis than DS-ECG.
Park
J-W
JW
Cardiology/Angiology Division, Hoyerswerda Hospital, Hoyerswerda, Germany. jai-wunpark@t-online.de
Leithäuser
B
B
Vrsansky
M
M
Jung
F
F
D000368:Aged; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000378:metabolism; D023921:Coronary Stenosis / Q000473:pathology*; D004280:Dobutamine / Q000494:pharmacology*; D004562:Electrocardiography / Q000379:methods*; D004594:Electrophysiology / Q000379:methods; D005260:Female; D006801:Humans; D053798:Magnetocardiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011336:Probability; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted
D004280:Dobutamine