Volume 10, Issue 6, Pages 864-872 (June 2013) Impact of the Advisa MRI pacing system on the diagnostic quality of cardiac MR images and contraction patterns of cardiac muscle during scans: Advisa MRI randomized clinical multicenter study results  Juerg Schwitter, MD, Emanuel Kanal, MD, FACR, FISMRM, Matthias Schmitt, MD, PhD, MRCP, Frederic Anselme, MD, Timothy Albert, MD, FACC, David L. Hayes, MD, FHRS, CCDS, David Bello, MD, Attila Tóth, MD, Yanping Chang, MS, Dirk van Osch, MSc, Torsten Sommer, MD, PhD  Heart Rhythm  Volume 10, Issue 6, Pages 864-872 (June 2013) DOI: 10.1016/j.hrthm.2013.02.019 Copyright © 2013 Heart Rhythm Society Terms and Conditions

Figure 1 Flowchart of patient recruitment and MR scans performed. CSPAMM = complementary spatial modulation of magnetization; LV = left ventricular; MRI = magnetic resonance imaging; RV = right ventricular. Heart Rhythm 2013 10, 864-872DOI: (10.1016/j.hrthm.2013.02.019) Copyright © 2013 Heart Rhythm Society Terms and Conditions

Figure 2 Examples of horizontal (HLA) and vertical (VLA) long-axis cine images of the heart in diastole and systole acquired with an SSFP technique in patients with a 2-chamber Advisa MRI pacemaker implanted in the left (panels A and C) and right (panel B) chest wall. A: HLA images: Minor susceptibility artifacts around the atrial and ventricular leads with characteristic dark signal voids and bright rims (arrows) due to nonlinear spatial misregistration and signal pileup, as a result of alterations in the static magnetic field near the ferromagnetic leads. The artifacts do not interfere with the ability to delineate the RV and LV endo- and epicardial borders and to evaluate cardiac function. Minor IPG-related off-resonance stripe artifacts in chest wall not reaching the heart (star). VLA images: No lead- or IPG-related artifacts in the LV and LA region. Minor IPG-related susceptibility artifacts with dark signal voids in the superior left chest wall (curved arrow) and IPG-related stripe artifacts in the middle and caudal chest wall (star), not interfering with the ability to assess the heart. Quality for functional LV and RV assessment was rated excellent (grade 1) and good (grade 2), respectively. B: HLA images: Subtle susceptibility artifacts around the atrial (short arrow) and the ventricular (long arrow) lead. Star: Minor signal void due to the IPG in the right chest wall not reaching the heart. VLA images: No lead- or IPG-related artifacts. Quality for LV and RV functional assessment was rated excellent (grade 1). C: HLA images: Susceptibility artifacts around the atrial (short arrow) and the ventricular (long arrow) lead without relevant interference to evaluate RV and LV function. However, pronounced IPG-related susceptibility artifacts with dark signal voids (curved arrow) and IPG-related stripe artifacts (star) affect the apical lateral and septal segments of the LV. VLA images: No lead- or IPG-related artifacts in the LV and the LA region but severe IPG-related susceptibility (curved arrows) and off-resonance stripe artifacts (star) affect the LV apical anterior and inferior segments. Quality for functional LV and RV assessment was rated nondiagnostic (grade 7) and poor (grade 4), respectively. IPG = implantable pulse generator; LA = left atrial; LV = left ventricular; MRI = magnetic resonance imaging; RV = right ventricular; SSFP = steady-state free precession. Heart Rhythm 2013 10, 864-872DOI: (10.1016/j.hrthm.2013.02.019) Copyright © 2013 Heart Rhythm Society Terms and Conditions

Figure 3 Examples for CSPAMM acquisitions without (A) and with (B) an artifact related to the pacing lead in the RV (5 representative images are shown out of 20 images covering the cardiac cycle; temporal resolution per image: 35ms). The corresponding top rows show respective raw (magnitude) images, and the bottom rows show the tracked tagging points (red points represent points that needed interpolation because of too large errors; for details, see the Method section). In the bottom row, most points needed interpolation (red points) in the inferoseptal segment. In this region, a signal loss is seen owing to the pacing lead (red circle in the magnitude images). Lower left corner: milliseconds after R-wave trigger. Cross: reference point for slice segmentation. CSPAMM = complementary spatial modulation of magnetization; RV = right ventricular. Heart Rhythm 2013 10, 864-872DOI: (10.1016/j.hrthm.2013.02.019) Copyright © 2013 Heart Rhythm Society Terms and Conditions

Figure 4 Quality of SSFP acquisitions for the LV and the RV. Distribution of image quality for the LV (A, n = 111) and the RV (B, n = 120). Grades 1–3 for the LV and grades 1 and 2 for the RV represent good or excellent image quality. Nondiagnostic quality is graded 7 and 5 for the LV and the RV, respectively. LV = left ventricular; RV = right ventricular; SSFP = steady-state free precession. Heart Rhythm 2013 10, 864-872DOI: (10.1016/j.hrthm.2013.02.019) Copyright © 2013 Heart Rhythm Society Terms and Conditions

Figure 5 Systolic segmental deformation in paced and nonpaced patients assessed by CMR tagging. A: A dyssynchronous systolic contraction pattern in a patient during RV pacing is shown (image data of this patient are shown in Figure 3B). The segments of the lateral LV wall (blue lines for segments 2/3) show an initial positive cFS%, that is, a stretching (shaded blue area), which is followed by a contraction phase with the delayed peak cFS% (blue arrow) in comparison to the peak cFS% of the other LV segments (black arrows). The septal segments (dashed lines for segments 5/6) contribute little to the overall LV shortening (shaded red area) resembling a left bundle brunch block pattern.7 B: Homogeneous contraction pattern in a nonpaced patient (image data of this patient are shown in Figure 3A). C: Homogeneous contraction pattern in patients during an AOO pacing mode (n = 8) with a homogeneous timing of deformation in all segments. Segment 2 appears to contribute most to the LV systolic deformation in this patient group. The sample size was not sufficient to further explore this possible difference. D: In the nonpaced patient group (n = 4), a homogeneous deformation pattern in all 6 LV segments is observed in agreement with the observation obtained in the patient example in panel B. cFS% = circumferential fiber shortening; CMR = cardiac magnetic resonance; LV = left ventricular; RV = right ventricular; SSFP = steady-state free precession. Heart Rhythm 2013 10, 864-872DOI: (10.1016/j.hrthm.2013.02.019) Copyright © 2013 Heart Rhythm Society Terms and Conditions