Using body surface mapping to detect vulnerability to ventricular arrhythmias in patients with coronary artery...

In order to examine the clinical usefulness of the vulnerability map, body surface mapping was performed in ten normal subjects and 32 patients with CAD using dipyridamole infusion to induce ventricular arrhythmias. A vulnerability map and the vulnerability index (VI) proposed by Urie et al. were constructed from QRS and T isointegral maps in the control state and QRST isointegral map after dipyridamole infusion. Premature ventricular complexes (PVCs) did not occur in normal subjects but occurred in 13 patients after dipyridamole infusion. The vulnerability index in normal subjects was significantly lower than that in patients without PVCs (8.3 +/- 1.7 vs 10.4 +/- 1.7, P less than 0.01). Patients with PVCs showed increased density of contour lines in the vulnerability map and significantly higher VI than those without PVCs (12.6 +/- 2.1 vs 10.4 +/- 1.7, P less than 0.01). This result suggests that a higher vulnerability index indicates that the condition of the cardiac muscle is at high risk of ventricular arrhythmias. It is concluded that the vulnerability map is useful for assessing whether or not the cardiac state is at high risk of ventricular arrhythmias in CAD.