The relation between conduction disturbances and coronary pathology is often uncertain. The aim of this study was to examine the location of coronary lesions in patients who have an indication for a permanent pacemaker.
Between 2001 and 2006, 203 consecutive patients (121 men (59%), mean age, 65 ± 10) who had severe conduction disturbance underwent coronary angiography before pacemaker implantation. Third degree AV block was present in 172 (84%), sick sinus syndrome in 21 (11%), and Mobitz II, second degree AV block in 10 (5%). The coronary angiographic study included stenosis severity and classification of pathological anatomy. Sixty-two age-matched subjects with coronary artery lesions > 50% but without conduction disturbance made up the control group. The locations of coronary lesions were classified as follows: Type I: Lesions not related to septal branches or AV node (AVN) artery; Type II: Lesions involving the septal perforators of LAD but not RCA; Type III: Lesions compromising blood supply to SAN or AVN (No LAD septal involvement); and Type IV: Combination of Type II and Type III.
Of 203 patients, insignificant coronary pathology was found in 141 (70%- group X). Sixty-two patients (30%) had coronary stenoses > 50% (group I) and Type II coronary anatomy was the most prevalent (n = 24, 38.7%), followed by Type IV (n = 22, 35%). Type III was found in 10 (16%) and Type I in 6 (9.6%). This distribution of CAD was significantly different from the control group in whom the most prevalent lesion locations were Type III and I (39% and 31%, respectively) (P < 0.05).
Patients with severe conduction disturbances tend to have a specific coronary lesion distribution that involves either proximal LAD branches or a combination of this with significant RCA disease, compromising supply to sinoatrial or AV nodes.