Invasive Coronary Assessment in Myocardial Ischemia with No Obstructive Coronary Arteries

Figures

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  Fig. 1. Normal structure and function of coronary macrocirculation and microcirculation. (Reprinted from Taqueti and Di Carli10 with permission. Copyright ©2018, Elsevier)

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  Fig. 2. Invasive coronary assessment in INOCA. ACh, acetylcholine; CBF, coronary blood flow; CFR, coronary flow reserve; CMD, coronary microvascular dysfunction; FFR, fractional flow reserve; hMR, hyperemic microvascular resistance; IMR, index of microcirculatory restriction; INOCA, ischemia and no obstructive coronary artery disease

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  Fig. 3. Doppler wire tracing. A Doppler-tipped guidewire allows direct measurement of coronary flow velocity. Doppler peak flow velocities are averaged over three consecutive heartbeats at rest and during hyperemia to calculate resting and hyperemic average peak velocities, respectively

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  Fig. 4. Coronary physiology assessment using the thermodilution technique. Simultaneous recordings of aortic pressure (Pa; red tracing), distal coronary pressure (Pd; green tracing), their ratio (Pd/Pa; yellow tracing), and intracoronary temperature after consecutive injections of 3 boluses at rest (blue tracings) and 3 boluses during steady-state hyperemia (orange tracings). These recordings allow simultaneous measurement of fractional flow reserve (FFR), coronary flow reserve (CFR), and the index of microvascular resistance (IMR). The yellow arrows point to the average values of resting and hyperemic mean transient time (Tmn) as well as to the average distal coronary pressure (Pd) during hyperemia. These values are needed to derive CFR and IMR. (Reprinted from Candreva et al.37 with permission. Copyright ©2021, Elsevier)

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  Fig. 5. A representative case with positive provocative spasm testing. An example of a patient with A diffuse epicardial spasm of the left anterior descending artery (black arrows) provoked by intracoronary injection of 200μg acetylcholine (ACh) accompanied by recognizable chest pain (red dot on torso) and new-onset ischemic ECG changes (red arrows). B Coronary spasm, angina symptoms, and ECG changes resolved after intracoronary nitroglycerin (NTG) injection at the end of routine ACh testing. C After rechallenge with 200μg ACh 3 minutes later, no epicardial vasoconstriction was observed. However, the patient again reported recognizable chest pain, and ischemic ECG changes (red arrows) reoccurred, suggesting coexisting microvascular spasm refractory to NTG pre-treatment. (Reprinted from Seitz et al.73 with permission. Copyright ©2022, Elsevier)

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  Fig. 6. Acetylcholine rechallenge. A Sankey plot illustrating the results of the initial acetylcholine (ACh) spasm provocation test and the ACh rechallenge after nitroglycerin. Nitroglycerin was most effective in preventing focal epicardial spasm and least effective in patients with microvascular spasm. ACh rechallenge revealed coexisting nitroglycerin-refractory microvascular spasm in approximately 50% of patients with focal or diffuse epicardial spasm. (Reprinted from Seitz et al.73 with permission. Copyright ©2022, Elsevier)