Effect of left bundle branch block on TIMI frame count

Aim: Left bundle branch block is an independent risk factorfor cardiac mortality. In this study we aimed to evaluatecoronary blood flow with TIMI frame count in patients with left bundle branch block and angiographically proven normal coronary arteries.Materials and methods: We retrospectively studied 17 patients with left bundle branch block and as a control group 16 patients without left bundle branch block. All patientshad angiographically proven normal coronary arteries.Left bundle branch block was determined according to standart electrocardiographic criteria. The TIMI frame count was measured for each major coronary artery in each patient.Results: TIMI frame count for left anterior descending coronary artery was found to be significantly higher in patientswith left bundle branch block compared with patients without left bundle branch block (35.4±16.7 ve 23.8±4.5, p=0.012). TIMI frame counts for circumflex and right coronaryarteries were similar in patients with and without left bundle branch block (TIMI frame count for circumflex artery:32.4±15.4 ve 27.7±7.6, p=0.275; TIMI frame count for right coronary artery: 31.9±9.6 ve 27.0±8.6, p=0.141).Conclusion: We have found that TIMI frame count for left anterior descending coronary artery was higher in patients with left bundle branch block compared with patients without left bundle branch block whereas there were no difference for TIMI frame counts for circumflex and right coronary arteries. Impaired coronary blood flow in left anterior descending artery may help to explain the sintigraphic perfusion defects in septum of patients with left bundle branch block