Coronary Vascular (DYS) Function and Invasive Physiology Assessment: Insights into Bolus and Continuous Thermodilution Methods

Figures

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  Figure 1. Coronary vascular dysfunction—clinical settings and pathophysiological mechanisms. Abbreviations: ANOCA, angina with non-obstructive coronary arteries; CMD, coronary microvascular dysfunction: INOCA, ischemia with non-obstructive coronary arteries; MINOCA, myocardial with non-obstructive coronary arteries; MVA, microvascular angina; VSA, vasospastic angina.

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  Figure 2. Spasm provocative test suggestive of vasospastic angina. (A) Baseline coronary angiography revealing no significant stenosis. (B,C) Repeated coronary angiography after administration of 2 μg and 20 μg of Ach showing significant spasm with >90% induced stenosis in the circumflex artery. (D) Repeated coronary angiography after administration of intracoronary nitrates revealing complete regression of coronary spasm. (E) Baseline electrocardiogram. (F) Electrocardiogram after administration of intracoronary Ach and during anginal symptoms, showing new-onset ischemic alterations in anterolateral position.

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  Figure 3. Representative case of coronary spasm on a mild coronary plaque in a patient presenting with out of hospital cardiac arrest. (A) Electrocardiogram at hospital presentation showing anterolateral ST segment elevation and biphasic T waves. (B) Coronary angiography revealing no significant stenosis. (C) Coronary computed tomography revealing a mild plaque with calcific core in the proximal LAD (white arrow). (D) Repeated coronary angiography showing significant spasm occurring on the proximal LAD at the passage of the OCT probe (white arrow). (E) OCT image showing coronary spasm. (F) Coronary angiography after administration of intracoronary nitrates showing the regression of the spasm (white arrow). Abbreviations: MLA, minimal lumen area.

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  Figure 4. Microvascular assessment with the bolus thermodilution method showing high value of IMR (42 and low value of CFR (1.7), suggestive of coronary microvascular dysfunction.

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  Figure 5. Microvascular assessment with the continuous thermodilution method. (A) Bolus thermodilution assessment during saline infusion reproducing resting conditions (10 mL/min). (B) Bolus thermodilution assessment during saline infusion reproducing hyperemia (20 mL/min), showing low values of Q (95 mL/min) and high value of R (905 UW) suggestive of coronary microvascular dysfunction.