Safety of intracoronary Doppler flow measurement

Background with the introduction of Doppler-tipped guide wires, intracorona ry Doppler flow measurement has been increasingly accepted as an additional diagnostic approach in the catheterization laboratory. However, the safety of intracoronary Doppler flow measurement has not been well-investigated. The purpose of our study was to evaluate the safety of intracoronary Dopple r flow measurement using the Doppler FloWire (Cardiometrics, Mountain View, Calif). Methods and Results A total of 906 patients were examined by intracoronary Doppler with a 0.014-inch or an 0.018-inch Doppler FloWire. For coronary fl ow reserve measurement, intracoronary injection of adenosine or papaverine was used. OF the patients studied, 77 were cardiac transplant recipients an d 829 were patients who had not received a transplant, of whom 617 had unde rgone diagnostic coronary procedures and 212 had coronary interventions. In 27 (2.98%) of 906 patients adverse cardiac events were observed. Fifteen ( 1.66%) of 906 patients had severe transient bradycardia develop (asystole o r second- to third-degree atrioventricular block) after intracoronary admin istration of adenosine, 14 of which occurred in the right coronary artery a nd 1 in the left anterior descending artery. Nine (0.99%) of 906 patients h ad coronary spasm during the passage of the Doppler wire (5 in the right co ronary artery, 4 in the left anterior descending artery). Two (0.22%) of 90 6 patients had ventricular fibrillation during the procedure. Hypotension w ith bradycardia and ventricular extrasystole each occurred in 1 (0.11%) of 906 patients. The incidence of complication was significantly higher in tra nsplant recipients than in patients who underwent either diagnostic or inte rventional procedures (12.99% vs 2.43% vs 0.94%, P < .001). The Doppler mea surements in the right coronary artery were associated with a higher incide nce of complications, especially bradycardia, compared with the left anteri or descending and the left circumflex arteries (right coronary, 5.87% vs le ft anterior descending, 1.05% vs left circumflex, 0.17%; P < .001). All com plications were cured medically. Conclusion Intracoronary Doppler flow measurement with Doppler wires and in tracoronary administration of adenosine is a safe method. However, severe c omplications such as bradycardia and coronary spasm con occur. Attention sh ould be paid to the examination of the right coronary artery, especially in heart transplant recipients.