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Double mitral and aortic mechanical valves present an access challenge when planning a ventricular tachycardia (VT) ablation. In this case report, we describe a patient who was considered for stereotactic ablative radiotherapy but was unable to proceed due to unfavorable anatomy making them at high risk of fistula formation. The patient went on to have an endocardial VT ablation via mini-thoracotomy and transapical access without complication. This case highlights the need for careful consideration when planning treatment for patients with double mechanical valves.

Background Clinical studies have reported that epicardial adipose tissue (EpAT) accumulation associates with the progression of atrial fibrillation (AF) pathology and adversely affects AF management. The role of local cardiac EpAT deposition in disease progression is unclear, and the electrophysiological, cellular, and molecular mechanisms involved remain poorly defined. Objectives The purpose of this study was to identify the underlying mechanisms by which EpAT influences the atrial substrate for AF. Methods Patients without AF undergoing coronary artery bypass surgery were recruited. Computed tomography and high-density epicardial electrophysiological mapping of the anterior right atrium were utilized to quantify EpAT volumes and to assess association with the electrophysiological substrate in situ. Excised right atrial appendages were analyzed histologically to characterize EpAT infiltration, fibrosis, and gap junction localization. Co-culture experiments were used to evaluate the paracrine effects of EpAT on cardiomyocyte electrophysiology. Proteomic analyses were applied to identify molecular mediators of cellular electrophysiological disturbance. Results Higher local EpAT volume clinically correlated with slowed conduction, greater electrogram fractionation, increased fibrosis, and lateralization of cardiomyocyte connexin-40. In addition, atrial conduction heterogeneity was increased with more extensive myocardial EpAT infiltration. Cardiomyocyte culture studies using multielectrode arrays showed that cardiac adipose tissue-secreted factors slowed conduction velocity and contained proteins with capacity to disrupt intermyocyte electromechanical integrity. Conclusions These findings indicate that atrial pathophysiology is critically dependent on local EpAT accumulation and infiltration. In addition to myocardial architecture disruption, this effect can be attributed to an EpAT-cardiomyocyte paracrine axis. The focal adhesion group proteins are identified as new disease candidates potentially contributing to arrhythmogenic atrial substrate.

To maximize arterial grafts, left internal mammary (LIMA) sequential and y grafts are used. The aim is to compare the angiographic patency of the LIMA in these configurations.Between 2002 and 2020, angiography was performed on 1000 patients who either had a single (570), sequential (100), or LIMA y (129) graft. The LIMA was divided into segments (S); S1: LIMA inflow to the first anastomosis, S2: terminal portion of the LIMA to left anterior descending (LAD), and S3; the y-limb anastomosis to a coronary. S1 and S2 patency analysis was carried out with logistic regression.Failure of the S1 and S2 was 3.7% single, 9% sequential, and 6.2 y graft (P = .049). Segment 1 failed in 3.7% in single, 5% in sequential, and 0.8% in y grafts (P = .049). Segment 3 failure was 10.3%. Regression revealed female sex and sequential grafts were associated with decreased S1 and S2 patency.Single grafts have the best patency. Failure in sequential grafts leads to increased occlusion of the LIMA inflow, whereas y-graft failure tends to occlude the y limb. When arterial conduit is sparse, a y graft should be considered.

Background Mitral valve procedures remain a surgical challenge in the presence of extensive annular calcification, which presents a formidable technical challenge. Aggressive debridement is limited by risk of serious complications and the technical complexity of pericardial patch reconstruction of the debrided area. Methods An open surgical approach with a transcatheter valve allows the valve to be placed under direct visualisation to facilitate positioning and to evaluate the likelihood of both perivalvular leakage and atrioventricular disruption. The open approach has the additional advantage of performing concomitant surgeries like other valve procedures, arrhythmias surgeries and coronary bypass. Results We present our experience with open surgical mitral valve replacement (MVR) using transcatheter valve in different patients requiring varied procedures. These patients were not suitable for MVR using standard prosthetic valve and techniques. They were also not suitable for percutaneous MVR because of heavily calcified anterior mitral leaflet and the other concomitant procedures required. Conclusions Open MVR with a transcatheter balloon-expandable valve can avoid the need for technically challenging and high-risk decalcification of mitral annulus. These novel techniques using transcatheter valves can be successful in complex cases where standard prosthetic valves are impossible to implant in a heavily calcified mitral annulus.

Background: Endocardial-epicardial dissociation and focal breakthroughs in humans with atrial fibrillation (AF) have been recently demonstrated using activation mapping of short 10-second AF segments. In the current study, we used simultaneous endo-epi phase mapping to characterize endo-epi activation patterns on long segments of human persistent AF. Methods: Simultaneous intraoperative mapping of endo- and epicardial lateral right atrium wall was performed in patients with persistent AF using 2 high-density grid catheters (16 electrodes, 3 mm spacing). Filtered unipolar and bipolar electrograms of continuous 2-minute AF recordings and electrodes locations were exported for phase analyses. We defined endocardial-epicardial dissociation as phase difference of ≥20 ms between paired endo-epi electrodes. Wavefronts were classified as rotations, single wavefronts, focal waves, or disorganized activity as per standard criteria. Endo-Epi wavefront patterns were simultaneously compared on dynamic phase maps. Complex fractionated electrograms were defined as bipolar electrograms with ≥5 directional changes occupying at least 70% of sample duration. Results: Fourteen patients with persistent AF undergoing cardiac surgery were included. Endocardial-epicardial dissociation was seen in 50.3% of phase maps with significant temporal heterogeneity. Disorganized activity (Endo: 41.3% versus Epi: 46.8%, P =0.0194) and single wavefronts (Endo: 31.3% versus Epi: 28.1%, P =0.129) were the dominant patterns. Transient rotations (Endo: 22% versus Epi: 19.2%, P =0.169; mean duration: 590±140 ms) and nonsustained focal waves (Endo: 1.2% versus Epi: 1.6%, P =0.669) were also observed. Apparent transmural migration of rotational activations (n=6) from the epi- to the endocardium was seen in 2 patients. Electrogram fractionation was significantly higher in the epicardium than endocardium (61.2% versus 51.6%, P Conclusions: Simultaneous endo-epi phase mapping of prolonged human persistent AF recordings shows significant Endocardial-epicardial dissociation marked temporal heterogeneity, discordant and transitioning wavefronts patterns and complex fractionations. No sustained focal activity was observed. Such complex 3-dimensional interactions provide insight into why endocardial mapping alone may not fully characterize the AF mechanism and why endocardial ablation may not be sufficient. Graphic Abstract: A graphic abstract is available for this article.

Background The 3-dimensional (3D) nature of sinoatrial node (SAN) function has not been characterized in the intact human heart. Objective The purpose of this study was to characterize the 3D nature of SAN function in patients with structural heart disease (SHD) using simultaneous endocardial–epicardial (endo–epi) phase mapping. Methods Simultaneous intraoperative endo–epi SAN mapping was performed during sinus rhythm at baseline (SRbaseline) and postoverdrive suppression at 600 ms (SRpost-pace600) and 400 ms (SRpost-pace400) using 2 Abbott Advisor HD Grid Mapping Catheters. Unipolar and bipolar electrograms (EGMs) were exported for phase analysis to determine (1) activation exits; (2) wavefront propagation sequence; (3) endo–epi dissociation; and (4) fractionation. Comparison of these variables was made among the 3 rhythms from an endo–epi perspective. Results Sixteen patients with SHD were included. SRbaseline activations were unicentric and predominantly exited cranially (87.5%) with endo–epi synchrony. However, with overdrive suppression, a tendency for caudal exit shift and endo–epi asynchrony was observed: SRpost-pace600 vs SRbaseline: cranial endo 75% vs 87.5% (P = .046); cranial epi 68.8% vs 87.5% (P = 0.002); caudal endo 12.5% vs 6.2% (P = 0.215); caudal epi 25% vs 6.2% (P = .0003); and SRpost-pace400 vs SRbaseline: cranial endo 81.3% vs 87.5% (P = 0.335); cranial epi 68.7% vs 87.5% (P = 0.0034; caudal endo 12.5% vs 6.2% (P = .148); caudal epi 31.2% vs 6.2% (P = 0.0017), consistent with multicentricity. EGM fractionation was more prevalent with overdrive suppression. Conclusion During mapping of the intact human heart, SAN demonstrated redundancy of sinoatrial exits with postoverdrive shift in sites of earliest activation and epi–endo dissociation of sinoatrial exits.

Background Early degeneration of prosthetic aortic valve in transcatheter aortic valve replacement (TAVR) is a rare complication. Method We report the case of a 75-year-old woman who presented with severe calcific stenosis of Edwards SAPIEN-XT valve implanted only 4 years previously. She is a Jehovah’s Witness and has background of Sjogren’s syndrome with secondary cryoglobulinaemic vasculitis. She was not a suitable candidate for valve-in-valve TAVR in view of early prosthetic valve failure by calcification. Result She underwent surgical explantation of the Sapiens XT valve and mechanical aortic valve replacement. Conclusion To our knowledge, this is the first time that early TAVR valve degeneration and failure of an Edwards SAPIEN-XT valve was reported which required surgical replacement with a mechanical valve.

Summary Background The Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone (MGTX) showed that thymectomy combined with prednisone was superior to prednisone alone in improving clinical status as measured by the Quantitative Myasthenia Gravis (QMG) score in patients with generalised non-thymomatous myasthenia gravis at 3 years. We investigated the long-term effects of thymectomy up to 5 years on clinical status, medication requirements, and adverse events. Methods We did a rater-blinded 2-year extension study at 36 centres in 15 countries for all patients who completed the randomised controlled MGTX and were willing to participate. MGTX patients were aged 18 to 65 years at enrolment, had generalised non-thymomatous myasthenia gravis of less than 5 years' duration, had acetylcholine receptor antibody titres of 1·00 nmol/L or higher (or concentrations of 0·50–0·99 nmol/L if diagnosis was confirmed by positive edrophonium or abnormal repetitive nerve stimulation, or abnormal single fibre electromyography), had Myasthenia Gravis Foundation of America Clinical Classification Class II–IV disease, and were on optimal anticholinesterase therapy with or without oral corticosteroids. In MGTX, patients were randomly assigned (1:1) to either thymectomy plus prednisone or prednisone alone. All patients in both groups received oral prednisone at doses titrated up to 100 mg on alternate days until they achieved minimal manifestation status. The primary endpoints of the extension phase were the time-weighted means of the QMG score and alternate-day prednisone dose from month 0 to month 60. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00294658. It is closed to new participants, with follow-up completed. Findings Of the 111 patients who completed the 3-year MGTX, 68 (61%) entered the extension study between Sept 1, 2009, and Aug 26, 2015 (33 in the prednisone alone group and 35 in the prednisone plus thymectomy group). 50 (74%) patients completed the 60-month assessment, 24 in the prednisone alone group and 26 in the prednisone plus thymectomy group. At 5 years, patients in the thymectomy plus prednisone group had significantly lower time-weighted mean QMG scores (5·47 [SD 3·87] vs 9·34 [5·08]; p=0·0007) and mean alternate-day prednisone doses (24 mg [SD 21] vs 48 mg [29]; p=0·0002) than did those in the prednisone alone group. 14 (42%) of 33 patients in the prednisone group, and 12 (34%) of 35 in the thymectomy plus prednisone group, had at least one adverse event by month 60. No treatment-related deaths were reported during the extension phase. Interpretation At 5 years, thymectomy plus prednisone continues to confer benefits in patients with generalised non-thymomatous myasthenia gravis compared with prednisone alone. Although caution is appropriate when generalising our findings because of the small sample size of our study, they nevertheless provide further support for the benefits of thymectomy in patients with generalised non-thymomatous myasthenia gravis. Funding National Institutes of Health, National Institute of Neurological Disorders and Stroke.

The goal of this study was to describe functional endocardial-epicardial dissociation (FEED), signal complexities, and three-dimensional activation dynamics of the human atrium with structural heart disease (SHD).SHD commonly predisposes to arrhythmias. Although progressive remodeling is implicated, direct demonstration of FEED in the human atrium has not been reported previously.Simultaneous intraoperative mapping of the endocardial and epicardial lateral right atrial wall was performed by using 2 high-density grid catheters during sinus rhythm, pacing drive (600 ms and 400 ms cycle length), and premature extrastimulation (PES). Unipolar electrograms (EGMs) were exported into custom-made software for activation and phase mapping. Difference of ≥20 ms between paired endocardial and epicardial electrodes defined dissociation. EGMs with ≥3 deflections were classified as fractionated.Sixteen patients (mean age 60.5 ± 4.1 years; 18.7% with a history of atrial fibrillation) with SHD (43% ischemia, 57% valvular disease) were included. A total of 9,218 EGMs were analyzed. Compared with sinus rhythm, phase and activation analyses showed significant FEED during pacing at 600 ms and 400 ms (phase mapping 22.4% vs. 10% [p 0.0001] and 25.8% vs. 10% [p 0.0001], respectively; activation mapping 25.4% vs. 7.8% [p 0.0001] and 27.7% vs. 7.8% [p 0.0001]) and PES (phase mapping 34% vs. 10% [p 0.0001]; activation mapping 29.5% vs. 7.8% [p 0.0001]). Fractionated EGMs occurred significantly more during PES compared with sinus rhythm (50.2% vs. 39.5%; p 0.0001). Activation patterns differed significantly during pacing drive and PES, with preferential epicardial exit during the latter (15.9% vs. 13.8%; p = 0.046).Simultaneous endocardial-epicardial mapping revealed significant FEED with signal fractionation and preferential epicardial breakthroughs with PES. Such complex three-dimensional interaction in electrical activation provides mechanistic insights into atrial arrhythmogenesis with SHD.

Objectives This study aimed to determine the spatiotemporal stability of rotors and other atrial activation patterns over 10 min in longstanding, persistent AF, along with the relationship of rotors to short cycle-length (CL) activity. Background The prevalence, stability, and mechanistic importance of rotors in human atrial fibrillation (AF) remain unclear. Methods Epicardial mapping was performed in 10 patients undergoing cardiac surgery, with bipolar electrograms recorded over 10 min using a triangular plaque (area: 6.75 cm 2 ; 117 bipoles; spacing: 2.5 mm) applied to the left atrial posterior wall (n = 9) and the right atrial free wall (n = 4). Activations were identified throughout 6 discrete 10-s segments of AF spanning 10 min, and dynamic activation mapping was performed. The distributions of 4,557 generated activation patterns within each mapped region were compared between the 6 segments. Results The dominant activation pattern was the simultaneous presence of multiple narrow wave fronts (26%). Twelve percent of activations represented transient rotors, seen in 85% of mapped regions with a median duration of 3 rotations. A total of 87% were centered on an area of short CL activity ( Conclusions In patients with longstanding, persistent AF, activation patterns are spatiotemporally stable over 10 min. Transient rotors can be demonstrated in the majority of mapped regions, are spatiotemporally associated with short CL activity, and, when recurrent, demonstrate anatomical determinism.

It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR).This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR.Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment.Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018).In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise.

This study aimed to determine the spatiotemporal stability of rotors and other atrial activation patterns over 10 min in longstanding, persistent AF, along with the relationship of rotors to short cycle-length (CL) activity.The prevalence, stability, and mechanistic importance of rotors in human atrial fibrillation (AF) remain unclear.Epicardial mapping was performed in 10 patients undergoing cardiac surgery, with bipolar electrograms recorded over 10 min using a triangular plaque (area: 6.75 cmThe dominant activation pattern was the simultaneous presence of multiple narrow wave fronts (26%). Twelve percent of activations represented transient rotors, seen in 85% of mapped regions with a median duration of 3 rotations. A total of 87% were centered on an area of short CL activity (100 ms), although such activity had a positive predictive value for rotors of only 0.12. The distribution of activation patterns and wave-front directionality were highly stable over time, with a single dominant pattern within a 10-s AF segment recurring across all 6 segments in 62% of mapped regions.In patients with longstanding, persistent AF, activation patterns are spatiotemporally stable over 10 min. Transient rotors can be demonstrated in the majority of mapped regions, are spatiotemporally associated with short CL activity, and, when recurrent, demonstrate anatomical determinism.

Background— The pulmonary vein–left atrial (PV–LA) junction is key in pathogenesis of AF, and acute stretch is an important stimulus to AF. We aimed to characterize the response of the junction to acute stretch, hypothesizing that stretch would result in electrophysiological changes predisposing to re-entry. Methods and Results— Fifteen participants undergoing cardiac surgery underwent evaluation of the right superior PV–LA junction using an epicardial mapping plaque. In 10, this was performed before and after atrial stretch imposed by rapid volume expansion, and in 5, it was performed with an intervening observation period. Activation was characterized by conduction slowing and electrogram fractionation transversely across the PV–LA junction, with lines of block also demonstrated perpendicular to the junction. Conduction was decremental (plaque activation time 135.8±46.8 ms with programmed extra stimuli at 10 ms above effective refractory period versus 66.1±22.9 ms with pacing at 400 ms; P P =0.001). Right atrial pressure increased by 2.5±1.8 mm Hg ( P =0.002) with volume expansion. Stretch resulted in conduction slowing across the PV–LA junction (increase in activation time 10.9±14.6 ms in acute stretch group versus −0.1±4.5 ms in control group; P =0.002). Conduction slowing was more marked with programmed extra stimuli at 10 ms above effective refractory period than with stable pacing (13.4±16.5 ms versus 1.7±5.4 ms; P =0.003). Stretch resulted in a significant increase in fractionated electrograms (7.9%±7.0% versus −0.4±3.3; P =0.004). Conclusions— Acute stretch results in conduction slowing across the PV–LA junction, with a greater degree of signal complexity. This substrate may be important in AF initiation and maintenance by promoting re-entry.