Coronary artery spasm complicating PTCA: role of intracoronary nitroglycerin

During PTCA intracoronary (ic) nitroglycerin is used in our institution only in cases of suspected coronary artery spasm. In order to estimate the incidence of true spasm, records from 1400 consecutive PTCA procedures were retrospectively reviewed for use of ic nitroglycerin. For each of the 376 procedures where ic nitroglycerin was used, angiograms were reviewed to determine whether spasm had been present or whether there was some other complicating problem which had mimicked spasm. In 191 procedures (51%), spasm had apparently occurred. In 178 procedures (47%), there was evidence for dissection rather than spasm. Seven procedures (2%) had evidence for neither spasm nor dissection. These included three cases of guiding catheter injury, two procedures where unsuspected distal disease was found after opening of total occlusions, and one case each of branch vessel occlusion and no re-flow phenomenon. Spasm was more common during right coronary PTCA. It frequently occurred in areas remote from the PTCA site. In every instance spasm was reversed following administration of one or more boluses of ic nitroglycerin. On the basis of these data, coronary artery spasm occurs in 14% of PTCA procedures.