Slow Coronary Flow: Correlations with Myocardial Perfusion Tomography and Coronary Arteriography

Abstract

A reduction in velocity in coronary artery contrast filling during coronary arteriography that is called “slow coronary flow” is one of the reasons of myocardial ischemia. Ischemia mechanism hasn't been understood. We evaluated coronary arteriographic and scintigraphic properties in patients with a slow flow pattern (SFP). The study included 60 patients who revealed SFP in their coronary arteriograms. The control group consisted of 50 patients with normal myocardial perfusion and normal coronary arteries in their coronary arteriograms. The Thrombolysis in Myocardial Infarction (TIMI) flow count method was used for the assessment of slow coronary flow. Single day rest-stress Technetium-99m hexakis-2-methoxy-isobutyl isonitrile (Tc-99m MIBI) myocardial perfusion tomography was performed to all study patients. Patients with SFP revealed both higher frame counts in native coronary arteries and higher average frame counts. In control patients, the average frame count was 26.4 ± 3.5 (LAD: 35.4 ± 3.3, LCx: 22.5 ± 4.5, RCA: 21.5 ± 2.8). In patients with SFP the average frame count was 64.40 ± 16.64 (LAD: 85.75 ± 24.39, LCx: 57.21 ± 15.25, RCA: 53 75 ± 17.81) (p < 0.001). Myocardial perfusion tomography showed ischemia in 17 patients (Group 1), while 43 patients in Group 2 revealed no perfusion defect. There were no statistically significant differences between Groups 1 and 2 in frame counts. In conclusion, no correlation was observed between the time needed to fill a native coronary artery and ischemia even if there is SFP.