title: Coronary microvascular dysfunction: mechanisms and functional assessment.
abstract: Obstructive disease of the epicardial coronary arteries was recognized as the cause of angina pectoris >2 centuries ago, and sudden thrombotic occlusion of an epicardial coronary artery has been established as the cause of acute myocardial infarction for >100 years. In the past 2 decades, dysfunction of the coronary microvasculature emerged as an additional mechanism of myocardial ischaemia that bears important prognostic implications. The coronary microvasculature (vessels <300 μm in diameter) cannot be directly imaged in vivo, but a number of invasive and noninvasive techniques, each with relative advantages and pitfalls, can be used to assess parameters that depend directly on coronary microvascular function. These methods include invasive or noninvasive measurement of Doppler-derived coronary blood flow velocity reserve, assessment of myocardial blood flow and flow reserve using noninvasive imaging, and calculation of microcirculatory resistance indexes during coronary catheterization. These advanced techniques for assessment of the coronary microvasculature have provided novel insights into the pathophysiological role of coronary microvascular dysfunction in the development of myocardial ischaemia in different clinical conditions.
authors.affiliation: Vita Salute University and Scientific Institute San Raffaele, Via Olgettina, 58, 20132 Milano, Italy.
authors.forename: Paolo G
authors.initials: PG
authors.lastname: Camici
authors.affiliation: Department of Radiology, Oncology and Pathology, "Sapienza" Università di Roma, Policlinico Umberto I, Viale Regina Elena, 324, 00161 Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: d'Amati
authors.affiliation: CNR IBFM, Via Fratelli Cervi, 93, 20090 Segrate (MI), Italy.
authors.forename: Ornella
authors.initials: O
authors.lastname: Rimoldi
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000503:physiopathology*; D015150:Echocardiography, Doppler / Q000379:methods; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008833:Microcirculation / Q000502:physiology*; D049268:Positron-Emission Tomography / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods