THE VALUE OF THE INTRACORONARY ELECTROGRAM FOR THE EARLY DETECTION OF MYOCARDIAL-ISCHEMIA DURING CORONARY ANGIOPLASTY

The clinical value of intracoronary electrography for the detection of myocardial ischaemia was assessed during coronary angioplasty and compared to a standard technique of surface ECG monitoring. In 73 patients undergoing single lesion angioplasty, an intracoronary electrogram and four representative surface ECG leads were obtained. During angioplasty of the left anterior descending artery leads, I, V3, V5, V6 were recorded. For the circumflex artery leads I, aVL, aVF, V6, and for the right coronary artery leads II, III, aVF, V6 were monitored. Eight patients were excluded due to transient intraventricular conduction disturbances during balloon inflation; 65 patients remained for further analysis. Out of a total of 154 balloon inflations (35 in the circumflex, 71 in the left anterior descending and 48 in the right coronary artery), the percentage that produced a ≥ 1 mm ST segment elevation, the time to the appearance of a ≥ 1 mm ST segment elevation and the maximal ST segment elevation were recorded. During inflations in the circumflex artery, the respective values of these three parameters were 20%, 22.6 ± 11.5 s and 0.37 ± 0.80 mm in V6, the most sensitive surface lead, versus 70% (P<0.001), 14.4 ± 9.6 s (P<0.01) and 5.82 ± 6.35 mm (P<0.0001) on the intracoronary electrogram. For left anterior descending inflations the corresponding values in V3, the most sensitive surface lead, were 61%, 26.2 ± 13.2 s and 2.08 ± 2.32 mm versus 74% (NS), 18.3 ± 12.4 s (P<0.001) and 5.66 ± 5.52 mm (P<0.0001) on the intracoronary tracing. For right coronary artery inflations the corresponding values in III, the most sensitive surface lead, were 77%, 22.2 ± 12.8 s and 2.31 ± 1.65 mm versus 32% (P<0.0001), 29.8 ± 26.3 (NS) and 1.18 ± 2.19 mm (P<0.05). Keeping in mind that only four surface leads were monitored, these data suggest that intracoronary electrography is helpful for adequate monitoring of ischaemia during circumflex angioplasty. During left anterior descending angioplasty it adds some additional information, but it appears superfluous during right coronary angioplasty. © 1991 The European Society of Cardiology.