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Current Perspective No-Reflow Phenomenon. By Rezkalla and Kloner Circulation 2002 February 5 th. Overview. Introduction Historical Perspective Pathophysiology Diagnosis Clinical Presentation Management Advantages Measures Treatments Conclusion. Introduction.
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Current PerspectiveNo-Reflow Phenomenon By Rezkalla and Kloner Circulation 2002 February 5th
Overview • Introduction • Historical Perspective • Pathophysiology • Diagnosis • Clinical Presentation • Management • Advantages • Measures • Treatments • Conclusion
Introduction • Epicardial verses microvasculature • No-Reflow • Low-Reflow
Historical Perspective • Initially found in brain • Occurs in heart, skin, skeletal muscle and kidney • In hearts, mainly subendocardial myocardium • EM shows swollen endothelium, intra luminal endothelial protrusions occasional platelets, fibrin, and oedema • PTCA and emergency CABG
Pathophysiology 1 • Prolonged cessation of epicardial blood flow results in damage to microcirculation, which prevents restoration of normal flow • Inadequate cardiac scar • Process NOT an immediate event on reperfusion • NO-Reflow area increases with time
Pathophysiology 2 • Endothelial swelling and intra luminal protrusions occlude microvasulature • ? Why dexamethasone and Mannitol help • Intravasular plugging fibrin and platelets • Ibuprofen, PG E1, heparinised saline, platelet depletion
Pathophysiology 3 • Leukocytes • ? Neutropenia, CD18 Ab, Free radiacl scavenging • Microemboli • Atherosclerotic debris in thrombolysis, angioplasty, rotablation and stenting – more common in vein graft interventions
Reperfusion Ischaemia No Reflow Atheroembolism
Coronary occlusion Reperfusion Atheroembolism Endothelial damage Tissue oedema Platelet/fibrin Oxygen/free radicals Leukocytes Tissue contracture No reflow
Diagnosis 1 • Angiography • TIMI flow (thrombolysis in myocardial infarction) • Grade 0 no flow • Garde 1 fails to opacify whole artery • Grade 2 opacification of coronaries but slow • Grade 3 normal • Quantify further using TIMI frame count
Diagnosis 2 • Coronary doppler • Serial ECGs • PET • MRI • Myocardial contrast echocardiography
Clinical Presentation • Cath Lab post angioplasty • CCU after thrombolysis • Preinfact angina reduces chance of no-reflow • No-Reflow linked to • Ventricular arrhythmias • Early CCF • Cardiac rupture • Death • Post CABG • Decreased EF despite completely successful revasculisation
Management advantages • May not decrease infarct size • Speed healing of necrotic area • Reduce infarct expansion and aneurysm formation • Help collateral circulation
Management measures • Retrieval of debris in vein grafts and after atherectomy • IABP • GP IIb/IIIa clinical and lab evidence • Anti-leukocyte Abs and complement inhibitors
Management treatments • Calcium channel blockers eg Verapamil • Adenosine • ATP K+ channel opener eg Nicorandil • Papaverine • Urokinase no good • Cardioplegia and transplant
Conclusion • Previous 2 decades concentrated on epicardial arteries, next decade will concentrate on microvascular perfusion