Two different coronary blood flow velocity patterns in thrombolysis in myocardial infarction flow grade 2 in acute myocardial infarction: insight into mechanisms of microvascular dysfunction

J Am Coll Cardiol. 2002 Nov 20;40(10):1755-60. doi: 10.1016/s0735-1097(02)02486-5.


Objectives: We sought to determine which of the two main potential mechanisms underlying Thrombolysis In Myocardial Infarction flow grade 2 (TIMI-2 flow) operate in an individual patient who has had an acute myocardial infarction (AMI).

Background: Systolic flow reversal (SFR) is a specific finding of capillary damage, the no-reflow phenomenon. The coronary blood flow velocity (CBFV) pattern of thromboemboli, however, remains unknown.

Methods: Data on 105 patients with AMI (57 with anterior and 48 with nonanterior cases) who underwent a coronary intervention were analyzed. The CBFV was recorded by a Doppler guide wire, and tissue perfusion was assessed with myocardial contrast echocardiography (MCE).

Results: Study patients were classified into three groups according to TIMI grade and the presence or absence of SFR: 1) TIMI-3 flow (n = 80); 2) TIMI-2 flow with SFR (SFR[+], n = 14); and 3) TIMI-2 flow without SFR (SFR[-], n = 11). Diastolic CBFV was the lowest in SFR(-) (TIMI-3 vs. SFR[+] vs. SFR[-]: 34 vs. 31 vs. 9 cm/s), and the systolic to diastolic CBFV ratio was also the highest in SFR(-) (0.43 vs. -0.18 vs. 0.66). The no-reflow phenomenon documented by MCE was found in all patients in the SFR(+) group, but in only one patient (10%) in the SFR(-) group. Intracoronary thrombus was more frequently found in SFR(-) than in SFR(+) (91% vs. 14%, p < 0.05).

Conclusions: At least two different CBFV patterns are noted in patients with reperfused AMI who have TIMI-2 flow. Capillary damage is mostly responsible for SFR(+), and SFR(-) is seen in thromboemboli possibly due to increased coronary arterial resistance.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Aged
  • Blood Flow Velocity / drug effects*
  • Blood Flow Velocity / physiology*
  • Coronary Vessels / physiopathology*
  • Diastole / drug effects
  • Diastole / physiology
  • Female
  • Follow-Up Studies
  • Hemodynamics / drug effects
  • Hemodynamics / physiology
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction / drug therapy*
  • Myocardial Infarction / physiopathology*
  • Predictive Value of Tests
  • Regression Analysis
  • Stroke Volume / drug effects
  • Stroke Volume / physiology
  • Systole / drug effects
  • Systole / physiology
  • Thrombolytic Therapy / methods*