case_images: PMC11799938_01
case_images: (A) ECG and presence or absence of chest pain during right ventricular pacing and native rhythm. (B) Strain analysis during native rhythm. (C) Strain analysis during right ventricular pacing (VVI:110 b.p.m.).
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case_images: The QRS duration during the RVP was 146 ms (Figure 1A). On echocardiography, no left ventricular dyssynchrony was observed during native rhythm (QRSd: 54 ms), and the global longitudinal strain (GLS) was -18.8 (Figure 1B). However, abnormalities in left ventricular wall motion, such as apical rocking and septal flash (both indicative of dyssynchrony) appeared during RVP, while the GLS decreased, particularly in the septal region (GLS: -10.9; Figure 1C). IMR   2.5) for CMD (CFR, 1.5; normalized IMR, 27 U; RRR, 1.6; Figure 3C). In the RCA, the CFR was 2.2, the normalized IMR was 32 U, and the RRR was 2.3 (Figure 3D). In addition, chest pain was observed during RVP (Figure 1A).
case_images: (A) Right coronary artery (LAO-CRANIAL view). (B) Left coronary artery (RAO-CAUDAL view).
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case_images: Coronary angiography revealed no right coronary artery (RCA) stenosis (Figure 2A). Segment #7 (Figure 2B); however, the fractional flow reserve measured with nicorandil was 0.86. Subsequently, an acetylcholine provocation test (doses: RCA 20 and 50 microg, LAD 50 and 100 microg) was performed, but no electrocardiogram changes or coronary spasms of more than 90% were induced under angiographic guidance.
case_images: (A) CoroFlow evaluation of the LAD during native rhythm. (B) The RCA during native rhythm. (C) The LAD during right ventricular pacing (VVI:110 b.p.m.). (D) The RCA during right ventricular pacing (VVI:110 b.p.m.).
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case_images: IMR) of 19 U, and a resistive reserve ratio (RRR) of 3.3 (Figure 3A). In the RCA under native rhythm, the results were CFR 3.8, normalized IMR 30 U, and RRR 4.3 (Figure 3B). IMR   2.5) for CMD (CFR, 1.5; normalized IMR, 27 U; RRR, 1.6; Figure 3C). In the RCA, the CFR was 2.2, the normalized IMR was 32 U, and the RRR was 2.3 (Figure 3D). In addition, chest pain was observed during RVP (Figure 1A).