Radial and Circumferential CMR-Based RV Strain Predicts Low R Wave Amplitude after ICD Implantation in Patients with Arrhythmogenic Cardiomyopathy

Figures

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  Figure 1. Representative CMR images of RV stain and fat infiltration from ACM patients with and without unfavorable R wave amplitude at ICD implantation. (A,B) Representative images and strain pattern from an ACM patient with low RWA (R wave amplitude of 3.6 mV at intrinsic sinus rhythm). (C,D) Representative images and strain pattern from an ACM patient with acceptable RWA (R wave amplitude of 11.7 mV at intrinsic sinus rhythm). Measurement of RV strain by CMR feature–tracking were displayed in (A,C) (upper and mid panel). The endo (yellow) and epicardial (blue) contours were delineated at the end-diastole phase. The RV global radial and circumferential strain (GCS, GRS) were obtained from the short-axis ((A,C) Upper panel), while the global longitudinal strain was measured from 4-chamber view ((A,C) mid), respectively. The lower peak circumferential ((B,D) upper panel), radial ((B,D) mid panel), and longitudinal ((B,D) lower panel) strain of the right ventricle demonstrated more severe abnormalities of the RV strain in the patient with final low RWA. CMR images from mDixon’s water-fat separation imaging were displayed at (A,C) (lower panel).

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  Figure 2. The linear relationship between right ventricular structural, functional strain parameters, and R wave amplitude. (A–D) Correlation between right ventricular (RV) ejection fraction, RV end-diastolic diameter, RV end-diastolic volume index, RV end-systolic volume index, and R wave amplitude (RWA) of ICD lead. (E–G) Correlation between RV global longitudinal, circumferential and radial strain, and RWA.

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  Figure 3. Receiver operating curves of RV parameters and low RWA. (A) Receiver operating curves showing the predictive performance of RV parameters in identifying patients with low RWA after ICD implantation in all ACM patients. (B) Receiver operating curves showing the predictive performance of RV parameters in identifying patients with low RWA after ICD implantation in ACM patients with LV involvement.

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  Figure 4. Bland–Altman analysis of RV strain for intra- and inter-observer variability. (A–C) Variability of intra-observer for RVGRS, RVGLS and RVGCS quantification. (D–F) Variability of inter-observer for RVGRS, RVGLS and RVGCS quantification. Red dashed line: bias error; black dashed lines: 95% limits of agreement.