CORONARY ANGIOGRAPHIC CHARACTERISTICS OF PATIENTS WITH PERMANENT ARTIFICIAL PACEMAKERS

Background The cause of severe cardiac conduction disturbances is ofte n uncertain. The aim of this study was to examine a group of patients with permanent pacemakers who underwent coronary arteriography to dete rmine the extent of coronary atherosclerotic disease that might be res ponsible for the conduction disturbances. Methods and Results Forty-th ree consecutive patients with a permanent pacemaker and 36 matched con trol patients were investigated. The coronary angiographic study inclu ded measurement of diameter and stenosis severity, qualitative assessm ent of flow, and classification of pathological anatomy, particularly the blood supply to territories supplying the different segments of th e conduction system. Among 43 patients with a permanent pacemaker, 27 had ischemic heart disease (17 after coronary artery bypass graft surg ery). The conduction disturbance was infranodal in 28 patients, sinus nodal in 6, AV nodal in 4, and complete AV block of unspecified origin in 5. Patients with permanent pacemakers had a coronary artery pathol ogy compromising blood flow to the septal branches and the right coron ary artery (type IV anatomy). This pattern was significantly different from the matched control patients, in whom the most prevalent coronar y anatomy was the combination of right coronary artery with distal lef t anterior descending artery (not involving the septal branches) lesio ns (P=.007). Conclusions Patients with coronary artery disease and sev ere conduction disturbances that require implantation of permanent pac emakers are more likely to have a specific pathological coronary anato my that combines a compromised blood flow to the septal branches of th e left anterior descending artery with right coronary artery lesions. The location of lesions in the coronary tree rather than severe diffus e atherosclerosis appears to be responsible for the conduction disturb ances.