Feb 17, 2000

Coronary microcirculatory vasoconstriction during ischemia in patients with unstable angina

Journal of the American College of Cardiology
Mario MarzilliAntonio L'Abbate

Abstract

To verify the behavior of coronary microvascular tone during spontaneous ischemia in patients with unstable angina (UA). In UA, the pathogenetic role of vasoconstriction is classically confined at the stenotic coronary segment. However, microcirculatory vasoconstriction has been also suggested by previous experimental and clinical studies. The study included 10 patients with UA (recent worsening of anginal threshold and appearance of angina at rest) and single-vessel CAD. Blood flow velocity was monitored by a Doppler catheter in the diseased artery. Transstenotic pressure gradient was monitored by aortic and distal coronary pressure monitoring. Stenosis resistance was calculated as the ratio between pressure gradient and blood flow, microvascular resistance as the ratio between distal pressure and blood flow. Measurements were obtained at baseline, following intracoronary adenosine (2 mg) and during transient ischemia. Aortic and distal coronary pressures were also measured during balloon coronary occlusion. Adenosine did not affect stenosis resistance, while it decreased (p < 0.05) microvascular resistance to 52 +/- 22% of baseline. Angina and ischemic ST segment shift were associated with transient angiographic coronary occl...Continue Reading

  • References43
  • Citations38

References

  • References43
  • Citations38

Mentioned in this Paper

Coronary Circulation
Ischemia
Arterial System
Adenosine
Blood Flow Velocity
Pathologic Vasoconstriction
Diastolic Blood Pressure
Doppler Ultrasound Imaging
Severity of Illness Index
Coronary Occlusion

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