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Objectives: This prospective pilot study assessed the feasibility of cardiovascular magnetic resonance (CMR) imaging during biventricular (BIV) pacing in patients with a CMR conditional cardiac resynchronization therapy defibrillator (CRT-D) and compared the results with invasive volume measurements. Methods: Ten CRT-D patients underwent CMR imaging prior to device implantation (baseline) and six weeks after device implantation, including CRT-on and CRT-off modes. Left ventricular (LV) function, volumes, and strain measurements of LV dyssynchrony and dyscoordination were assessed. Invasive pressure–volume measurements were performed, matching the CRT settings used during CMR. Results: Post-implantation imaging enabled reliable cine assessment, but showed artefacts on late gadolinium enhancement images. After six weeks of CRT, significant reverse remodeling was observed, with a 22.7 ± 11% reduction in LV end-systolic volume during intrinsic rhythm (CRT-off). During CRT-on, the LV ejection fraction significantly improved from 27.4 ± 5.9% to 32.2 ± 8.7% (p < 0.01), and the strain assessment showed the abolition of the left bundle branch block contraction pattern. Invasively measured and CMR-assessed LV hemodynamics during BIV pacing were significantly associated. Conclusions: Post-CRT implantation CMR assessing acute LV pump function is feasible and provides important insights into the effects of BIV pacing on cardiac function and contraction patterns. LV assessment during CMR may constitute a future CRT optimization strategy. [ABSTRACT FROM AUTHOR]

Aims: Radiofrequency ablation (RFA) of the atrioventricular node (AVN) with His-bundle pacing (HBP) can cause rise in capture thresholds. Cryoablation (CRYO) may offer reversibility in case of threshold rise but has never been tested for AVN ablation in this setting. Our aim was to compare procedural characteristics and outcome of CRYO compared with RFA for AVN ablation in patients with HBP.Methods and Results: Forty-four patients with HBP underwent AVN ablation for an 'ablate and pace' indication. Cryoablation was performed in the first 22 patients and RFA in the following 22 patients. Procedural characteristics, success rates, and change in His capture thresholds were compared between groups. Distance from the ablation site to the His lead was measured using biplane fluoroscopy. Acute success was 100% with both strategies. Median procedural duration was significantly longer for CRYO {50 [interquartile range (IQR) 38-63] min} compared with RFA [36 (IQR, 30-41) min; P = 0.027]. An acute threshold rise of ≥1 V was observed in four CRYO (one complete loss of capture) and three RFA patients (P = 0.38), with all of the applications being within 6 mm of the His lead tip. During follow-up, nine patients had AVN re-conduction (six CRYO vs. three RFA; P = 0.58), but only four patients required a redo procedure (all CRYO; P = 0.09).Conclusion: Cryoablation does not offer any advantage over RFA for AVN ablation in patients with HBP and tended to require more redo procedures. If possible, a distance of ≥6 mm should be maintained from the His lead tip to avoid a rise in capture thresholds. [ABSTRACT FROM AUTHOR]

Aims Patient selection for cardiac resynchronization therapy (CRT) may be enhanced by evaluation of systolic myocardial stretching. We evaluate whether systolic septal rebound stretch (SRSsept) derived from speckle tracking echocardiography is a predictor of reverse remodelling after CRT and whether it holds additive predictive value over the simpler visual dyssynchrony assessment by apical rocking (ApRock). Methods and results The association between SRSsept and change in left ventricular end-systolic volume (ΔLVESV) at 6 months of follow-up was assessed in 200 patients. Subsequently, the additive predictive value of SRSsept over the assessment of ApRock was evaluated in patients with and without left bundle branch block (LBBB) according to strict criteria. SRSsept was independently associated with ΔLVESV (β 0.221, P  =   0.002) after correction for sex, age, ischaemic cardiomyopathy, QRS morphology and duration, and ApRock. A high SRSsept (≥optimal cut-off value 2.4) also coincided with more volumetric responders (ΔLVESV ≥ −15%) than low SRSsept in the entire cohort (70.0% and 56.4%), in patients with strict LBBB (83.3% vs. 56.7%, P  =   0.024), and non-LBBB (70.7% vs. 46.3%, P  =   0.004). Moreover, in non-LBBB patients, SRSsept held additional predictive information over the assessment of ApRock alone since patients that showed ApRock and high SRSsept were more often volumetric responder than those with ApRock but low SRSsept (82.8% vs. 47.4%, P  =   0.001). Conclusion SRSsept is strongly associated with CRT-induced reduction in left ventricular end-systolic volume and holds additive prognostic information over QRS morphology and ApRock. Our data suggest that CRT patient selection may be improved by assessment of SRSsept, especially in the important subgroup without strict LBBB. Clinical trial registration The MARC study was registered at clinicaltrials.gov: NCT01519908. [ABSTRACT FROM AUTHOR]

Aims: This study aims to define an atrioventricular (AV) delay optimization method for cardiac resynchronization therapy (CRT) with a quadripolar left ventricular (LV) lead based on intrinsic conduction intervals.Methods and Results: Heart failure patients with a left bundle branch block underwent CRT implantation with a quadripolar LV lead. Invasive LV pressure-volume loops were recorded during four biventricular and three multi-point pacing (MPP) settings, using four patient-specific paced AV delays. Haemodynamic response was defined as change in stroke work (Δ%SW) compared to intrinsic rhythm and was related to the following conduction intervals: right atrial pacing to right ventricular sensing interval (RAp-RVs), Q to LV sensing interval normalized to QRS duration (QLV/QRSd), PR-interval, and P-wave duration. In 44 patients, the largest Δ%SW (104 ± 76%) occurred at a paced AV delay of 128 ± 32 ms, at 47 ± 9% of RAp-RVs. Optimal AV delay of biventricular pacing (126 ± 26 ms) did not differ from MPP (126 ± 21 ms, P = 0.29). Intra-class correlation coefficient between optimal AV delays of different pacing configurations was 0.64 (0.45-0.78, P < 0.001). Although not statistically significant, Δ%SW at 50% of RAp-RVs (98 ± 74%) was closer to the maximal achievable Δ%SW increase than a fixed interval of 120 ms (96 ± 73%, P = 0.60). RAp-RVs, QLV/QRSd, PR interval, and P-wave duration were associated with the optimal AV delay in univariate analysis, but only RAp-RVs remained significantly associated in multivariate analysis (R = 0.69).Conclusion: The AV delay that provides highest haemodynamic response is similar for various LV pacing configurations and for MPP. An AV delay ∼50% of RAp-RVs creates an acute haemodynamic response close to the maximal patient-specific response. [ABSTRACT FROM AUTHOR]

Aims To determine the diagnostic yield of tissue characterization by cardiovascular magnetic resonance (CMR) in a large clinical population of patients with suspected acute myocarditis (AM) and to establish its diagnostic value within the 2013 European Society of Cardiology position statement criteria (ESC-PSC) for clinically suspected myocarditis. Methods and results In this retrospective study, CMR examinations of 303 hospitalized patients referred for work-up of suspected AM in two tertiary referral centres were analysed. CMR was performed at median 7 days (interquartile range 4–20 days) after clinical presentation and included cine imaging, T2-weighted imaging, and late gadolinium enhancement. CMR images were evaluated to assign each patient to a diagnosis. By using non-CMR criteria only, the 2013 ESC-PSC were positive for suspected myocarditis in 151 patients and negative in 30. In the remaining 122 patients, there was insufficient information available for ESC-PSC assessment, mostly due to lack of coronary angiography (CAG) before the CMR examination (n = 116, 95%). There were no in-hospital deaths. CMR provided a diagnosis in 158 patients (52%), including myocarditis in 104 (34%), myocardial infarction in 44 (15%), and other pathology in 10 patients (3%). Non-urgent CAG (>24 h after presentation) was performed before the CMR examination in 85 patients, of which 20 (24%) were done in patients with subsequently confirmed AM, which could potentially have been avoided if CMR was performed first. ESC-PSC was correct in diagnosing AM before the CMR in 50 of the 151 patients (33%) and was correct in ruling out AM in all the 30 patients (100%). However, ESC-PSC provided an incorrect diagnosis of AM in 27 of the 151 patients (18%), which was corrected by CMR through the identification of new cardiac disease that could explain the clinical syndrome. Patients with insufficient ESC-PSC information had a relatively low pre-test probability of coronary artery disease. In this group, CMR confirmed the diagnosis of AM in a relatively high percentage (44%) but still revealed myocardial infarction in 8% of them. Conclusion Tissue characterization by CMR provided a good diagnostic yield in this large clinical population of patients with suspected AM. CMR provided incremental diagnostic value to the ESC-PSC by ruling out the diagnosis of AM on one hand and by potentially sparing AM patients from CAG on the other. [ABSTRACT FROM AUTHOR]

Aims: Radiofrequency ablation (RFA) of the atrioventricular node (AVN) with His-bundle pacing (HBP) can cause rise in capture thresholds. Cryoablation (CRYO) may offer reversibility in case of threshold rise but has never been tested for AVN ablation in this setting. Our aim was to compare procedural characteristics and outcome of CRYO compared with RFA for AVN ablation in patients with HBP., Methods and Results: Forty-four patients with HBP underwent AVN ablation for an 'ablate and pace' indication. Cryoablation was performed in the first 22 patients and RFA in the following 22 patients. Procedural characteristics, success rates, and change in His capture thresholds were compared between groups. Distance from the ablation site to the His lead was measured using biplane fluoroscopy. Acute success was 100% with both strategies. Median procedural duration was significantly longer for CRYO {50 [interquartile range (IQR) 38-63] min} compared with RFA [36 (IQR, 30-41) min; P = 0.027]. An acute threshold rise of ≥1 V was observed in four CRYO (one complete loss of capture) and three RFA patients (P = 0.38), with all of the applications being within 6 mm of the His lead tip. During follow-up, nine patients had AVN re-conduction (six CRYO vs. three RFA; P = 0.58), but only four patients required a redo procedure (all CRYO; P = 0.09)., Conclusion: Cryoablation does not offer any advantage over RFA for AVN ablation in patients with HBP and tended to require more redo procedures. If possible, a distance of ≥6 mm should be maintained from the His lead tip to avoid a rise in capture thresholds., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aims: Patient selection for cardiac resynchronization therapy (CRT) may be enhanced by evaluation of systolic myocardial stretching. We evaluate whether systolic septal rebound stretch (SRSsept) derived from speckle tracking echocardiography is a predictor of reverse remodelling after CRT and whether it holds additive predictive value over the simpler visual dyssynchrony assessment by apical rocking (ApRock)., Methods and Results: The association between SRSsept and change in left ventricular end-systolic volume (ΔLVESV) at 6 months of follow-up was assessed in 200 patients. Subsequently, the additive predictive value of SRSsept over the assessment of ApRock was evaluated in patients with and without left bundle branch block (LBBB) according to strict criteria. SRSsept was independently associated with ΔLVESV (β 0.221, P = 0.002) after correction for sex, age, ischaemic cardiomyopathy, QRS morphology and duration, and ApRock. A high SRSsept (≥optimal cut-off value 2.4) also coincided with more volumetric responders (ΔLVESV ≥ -15%) than low SRSsept in the entire cohort (70.0% and 56.4%), in patients with strict LBBB (83.3% vs. 56.7%, P = 0.024), and non-LBBB (70.7% vs. 46.3%, P = 0.004). Moreover, in non-LBBB patients, SRSsept held additional predictive information over the assessment of ApRock alone since patients that showed ApRock and high SRSsept were more often volumetric responder than those with ApRock but low SRSsept (82.8% vs. 47.4%, P = 0.001)., Conclusion: SRSsept is strongly associated with CRT-induced reduction in left ventricular end-systolic volume and holds additive prognostic information over QRS morphology and ApRock. Our data suggest that CRT patient selection may be improved by assessment of SRSsept, especially in the important subgroup without strict LBBB., Clinical Trial Registration: The MARC study was registered at clinicaltrials.gov: NCT01519908., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)