Publications
164 results found
O'Connor M, Barbero U, Kramer DB, et al., 2023, Anatomic, histologic, and mechanical features of the right atrium: implications for leadless atrial pacemaker implantation., Europace, Vol: 25
BACKGROUND: Leadless pacemakers (LPs) may mitigate the risk of lead failure and pocket infection related to conventional transvenous pacemakers. Atrial LPs are currently being investigated. However, the optimal and safest implant site is not known. OBJECTIVES: We aimed to evaluate the right atrial (RA) anatomy and the adjacent structures using complementary analytic models [gross anatomy, cardiac magnetic resonance imaging (MRI), and computer simulation], to identify the optimal safest location to implant an atrial LP human. METHODS AND RESULTS: Wall thickness and anatomic relationships of the RA were studied in 45 formalin-preserved human hearts. In vivo RA anatomy was assessed in 100 cardiac MRI scans. Finally, 3D collision modelling was undertaken assessing for mechanical device interaction. Three potential locations for an atrial LP were identified; the right atrial appendage (RAA) base, apex, and RA lateral wall. The RAA base had a wall thickness of 2.7 ± 1.6 mm, with a low incidence of collision in virtual implants. The anteromedial recess of the RAA apex had a wall thickness of only 1.3 ± 0.4 mm and minimal interaction in the collision modelling. The RA lateral wall thickness was 2.6 ± 0.9 mm but is in close proximity to the phrenic nerve and sinoatrial artery. CONCLUSIONS: Based on anatomical review and 3D modelling, the best compromise for an atrial LP implantation may be the RAA base (low incidence of collision, relatively thick myocardial tissue, and without proximity to relevant epicardial structures); the anteromedial recess of the RAA apex and lateral wall are alternate sites. The mid-RAA, RA/superior vena cava junction, and septum appear to be sub-optimal fixation locations.
Butcher CJT, Cantor E, Sohaib A, et al., 2023, Variation in optimal hemodynamic atrio-ventricular delay of biventricular pacing with different endocardial left ventricular lead locations using precision hemodynamics., J Cardiovasc Electrophysiol, Vol: 34, Pages: 1431-1440
INTRODUCTION: It is not known whether the optimal atrioventricular (AVopt ) delay varies between left ventricular (LV) pacing site during endocardial biventricular pacing (BiVP) and may therefore needs consideration. METHODS: We assessed the hemodynamic AVopt in patients with chronic heart failure undergoing endocardial LV lead implantation. AVopt was assessed during atrio-BiVP with a "roving LV lead." Up to four locations were studied: mid-lateral wall, mid-septum (or a close alternative), site of greatest hemodynamic improvement, and LV lead implant site. The AVopt was compared to a fixed AV delay of 180 ms. RESULTS: Seventeen patients were included (12 male, aged 66.5 ± 12.8 years, ejection fraction 26 ± 7%, 16 left bundle branch block or high percentage of right ventricular pacing [RVP], QRS duration 167 ± 27 ms). In most locations (62/63), AVopt increased systolic blood pressure during BiVP compared with RVP (relative improvement 6 mmHg, interquartile range [IQR] 4-9 mmHg). Compared to a fixed AV delay, the hemodynamic improvement at AVopt was higher (1 mmHg, IQR 0.2-2.6 mmHg, p < .001). Within most patients (16/17), we observed a difference in AVopt between pacing sites (median paced AVopt 209 ms, IQR 117-250). Within this range, the hemodynamic impact of these differences was small (median loss 0.6 mmHg, IQR 0.1-2.6 mmHg). CONCLUSION: Within a patient, different endocardial LV lead locations have slightly different hemodynamic AVopt which are superior to a fixed AV delay. The hemodynamic consequence of applying an optimum from a different lead location is small.
Khan HR, Yakupoglu HY, Kralj-Hans I, et al., 2023, Left Atrial Function Predicts Atrial Arrhythmia Recurrence Following Ablation of Long-Standing Persistent Atrial Fibrillation., Circ Cardiovasc Imaging, Vol: 16
BACKGROUND: Left atrial (LA) function following catheter or surgical ablation of de-novo long-standing persistent atrial fibrillation (AF) and its impact on AF recurrence was studied in patients participating in the CASA-AF trial (Catheter Ablation vs. Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation). METHODS: All patients underwent echocardiography preablation, 3 and 12 months post-ablation. LA structure and function were assessed by 2-dimensional volume and speckle tracking strain measurements of LA reservoir, conduit, and contractile strain. Left ventricular diastolic function was measured using transmitral Doppler filling velocities and myocardial tissue Doppler velocities to derive the e', E/e', and E/A ratios. Continuous rhythm monitoring was achieved using an implantable loop recorder. RESULTS: Eighty-three patients had echocardiographic data suitable for analysis. Their mean age was 63.6±9.7 years, 73.5% were male, had AF for 22.8±11.6 months, and had a mean LA maximum volume of 48.8±13.8 mL/m2. Thirty patients maintained sinus rhythm, and 53 developed AF recurrence. Ablation led to similar reductions in LA volumes at follow-up in both rhythm groups. However, higher LA emptying fraction (36.3±10.6% versus 27.9±9.9%; P<0.001), reservoir strain (22.6±8.5% versus 16.7±5.7%; P=0.001), and contractile strain (9.2±3.4% versus 5.6±2.5%; P<0.001) were noted in the sinus rhythm compared with AF recurrence group following ablation at 3 months. Diastolic function was better in the sinus rhythm compared with the AF recurrence group with an E/A ratio of 1.5±0.5 versus 2.2±1.2 (P<0.001) and left ventricular E/e' ratio of 8.0±2.1 versus 10.3±4.1 (P<0.001), respectively. LA contractile strain at 3 months was the only independent predictor of AF recurrence. CONCLUSIONS: Following ablation for long-standing persistent AF, improvement in LA fun
O'Connor M, Shi R, Kramer DB, et al., 2023, Conduction system pacing learning curve: Left bundle pacing compared to His bundle pacing., Int J Cardiol Heart Vasc, Vol: 44, ISSN: 2352-9067
INTRODUCTION: Conduction system pacing (CSP), consisting of His bundle pacing (HBP) or left bundle branch area pacing (LBBAP) is a rapidly developing field. These pacing techniques result in single lead left ventricular resynchronisation. Understanding of the associated learning curve of the two techniques is an important consideration for new implanters/implanting centres. METHODS: We conducted a review of the first 30 cases of both HBP and LBBAP at The Royal Brompton Hospital. The procedural duration and fluoroscopy time were used as surrogates for the learning curve of each technique. RESULTS: Patient characteristics were similar in HBP and LBBAP groups; LV ejection fraction (46% vs 54%, p = 0.08), pre-procedural QRS duration (119 ms vs 128 ms, p = 0.32).Mean procedural duration was shorter for LBBAP than for HBP (87 vs 107mins, p = 0.04) and the drop in procedural duration was more marked in LBBAP, plateauing and remaining low at 80mins after the initial 10 cases. Fluoroscopic screening time mirrored procedural duration (8 min vs 16 min, p < 0.01). DISCUSSION/CONCLUSION: Our data suggest that the CSP learning curve was shorter for LBBAP than for HBP and appears to plateaux after the first 10 cases, however the HBP learning curve is longer with continued improvement over the first 30 cases. The shorter learning curve of LBBAP in conjunction with the superior electrical parameters and simplified programming mean the establishment of a CSP program is potentially easier with LBBAP compared to with HBP.
O'Connor M, Riad O, Shi R, et al., 2022, Left bundle branch area pacing in congenital heart disease, EUROPACE, ISSN: 1099-5129
Zakeri R, Ahluwalia N, Tindale A, et al., 2022, Long-term outcomes following catheter ablation versus medical therapy in patients with persistent atrial fibrillation and heart failure with reduced ejection fraction, EUROPEAN JOURNAL OF HEART FAILURE, Vol: 25, Pages: 77-86, ISSN: 1388-9842
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- Citations: 1
Nashat H, Habibi H, Heng EL, et al., 2022, Patient monitoring and education over a tailored digital application platform for congenital heart disease: A feasibility pilot study., Int J Cardiol, Vol: 362, Pages: 68-73
BACKGROUND: Patients with adult congenital heart disease (ACHD) are a rapidly growing cardiovascular population with increasing health needs and co-morbidities. Furthermore, their management requires frequent and ongoing hospital visits which can be burdensome. Digital health and remote monitoring have been shown to have a vast potential to enhance delivery of healthcare for patients, reducing their need for travel to clinic appointments therefore reducing costs to the patient and the healthcare service. METHODS: Patients over the age of 16 with a diagnosis of ACHD were invited to use the tailored digital application too. They were monitored for a period of 6 months. Information on patient demographics, time using the application, flagged events that prompted clinical reviews and their feedback through patient surveys were collected. RESULTS: A total of 103 patients were enrolled and registered to use the digital application tool. There were 57 (56%) males, median age at the time of enrolment was 39 (16-73) years. The majority (96%) had a moderate or complex ACHD according to the ACC/AHA classification. There was a total of 7 modules that were completed on a weekly basis. The median length of a participant session was 2.2 min and the mean time to complete a module was 21 s. In total, 35 (67%) felt that the application helped them better manage their cardiac condition. Almost all (94%) of patients expressed that they would like to continue using the application beyond the pilot. There were 18 flagged events during the 6 month observation period, and 50% of received early clinical intervention. CONCLUSION: Application based remote monitoring in this select group was well received and potentially holds large benefit to patients both clinically and economically. There were no safety concerns in our pilot feasibility study. Our data may inform much needed and timely investment in digital health.
Griffiths S, Behar JM, Kramer DB, et al., 2022, The long-term outcomes of cardiac implantable electronic devices implanted via the femoral route, Pacing and Clinical Electrophysiology, Vol: 45, Pages: 481-490, ISSN: 0147-8389
BACKGROUND: Conventional superior access for cardiac implantable electronic devices (CIEDs) is not always possible and femoral CIEDs (F-CIED) are an alternative option when leadless systems are not suitable. The long-term outcomes and extraction experiences with F-CIEDs, in particular complex F-CIED (ICD/CRT devices), remain poorly understood. METHODS: Patients referred for F-CIEDs implantation between 2002 and 2019 at two tertiary centers were included. Early complications were defined as ≤30 days following implant and late complications >30 days. RESULTS: Thirty-one patients (66% male; age 56 ± 20 years; 35% [11] patients with congenital heart disease) were implanted with F-CIEDs (10 ICD/CRT and 21 pacemakers). Early complications were observed in 6.5% of patients: two lead displacements. Late complications at 6.8 ± 4.4 years occurred in 29.0% of patients. This was higher with complex F-CIED compared to simple F-CIED (60.0% vs. 14.3%, p = .02). Late complications were predominantly generator site related (n = 8, 25.8%) including seven infections/erosions and one generator migration. Eight femoral generators and 14 leads (median duration in situ seven [range 6-11] years) were extracted without complication. CONCLUSIONS: Procedural success with F-CIEDs is high with clinically acceptable early complication rates. There is a notable risk of late complications, particularly involving the generator site of complex devices following repeat femoral procedures. Extraction of chronic F-CIED in experienced centers is feasible and safe.
Sarkozy A, Vijgen J, De Potter T, et al., 2022, An early multicenter experience of the novel high-density star-shaped mapping catheter in complex arrhythmias, JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY, Vol: 64, Pages: 223-232, ISSN: 1383-875X
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- Citations: 1
Malaczynska-Rajpold K, Jarman J, Shi R, et al., 2022, Beyond pulmonary vein isolation for persistent atrial fibrillation: sequential high-resolution mapping to guide ablation, JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY, Vol: 65, Pages: 53-62, ISSN: 1383-875X
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- Citations: 2
Shi R, Zaman JAB, Chen Z, et al., 2022, Novel aggregated multiposition noncontact mapping of atrial tachycardia in humans: From computational modeling to clinical validation, HEART RHYTHM, Vol: 19, Pages: 61-69, ISSN: 1547-5271
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- Citations: 1
Haldar S, Khan HR, Boyalla V, et al., 2021, Thoracoscopic surgical ablation versus catheter ablation as first-line treatment for long-standing persistent atrial fibrillation: the CASA-AF RCT, Efficacy and Mechanism Evaluation, Vol: 8, Pages: 1-122, ISSN: 2050-4365
<jats:sec id="abs1-1"> <jats:title>Background</jats:title> <jats:p>Standalone thoracoscopic surgical ablation may be more effective than catheter ablation in patients with long-standing persistent atrial fibrillation.</jats:p> </jats:sec> <jats:sec id="abs1-2"> <jats:title>Objectives</jats:title> <jats:p>To determine whether or not surgical ablation is clinically superior to catheter ablation as the first-line treatment strategy in long-standing persistent atrial fibrillation.</jats:p> </jats:sec> <jats:sec id="abs1-3"> <jats:title>Design</jats:title> <jats:p>This was a prospective, multicentre, randomised control trial.</jats:p> </jats:sec> <jats:sec id="abs1-4"> <jats:title>Setting</jats:title> <jats:p>Four NHS tertiary centres in England.</jats:p> </jats:sec> <jats:sec id="abs1-5"> <jats:title>Participants</jats:title> <jats:p>Adults with long-standing persistent atrial fibrillation, who had European Heart Rhythm Association symptom scores > 2 and who were naive to previous catheter ablation or thoracic/cardiac surgery.</jats:p> </jats:sec> <jats:sec id="abs1-6"> <jats:title>Interventions</jats:title> <jats:p>Minimally invasive thoracoscopic surgical ablation and conventional catheter ablation (control intervention).</jats:p> </jats:sec> <jats:sec id="abs1-7"> <jats:title>Mai
Obika BD, Dolezova N, Ponzo S, et al., 2021, Implementation of a mHealth solution to remotely monitor patients on a cardiac surgical waiting list: service evaluation, JAMIA OPEN, Vol: 4
Shi R, Chen Z, Pope MTB, et al., 2021, Individualized ablation strategy to treat persistent atrial fibrillation: Core-to-boundary approach guided by charge-density mapping, HEART RHYTHM, Vol: 18, Pages: 862-870, ISSN: 1547-5271
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- Citations: 10
Maclean E, Simon R, Ang R, et al., 2021, A multi-center experience of ablation index for evaluating lesion delivery in typical atrial flutter, PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, Vol: 44, Pages: 1039-1046, ISSN: 0147-8389
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- Citations: 3
Ma Y, Zaman JAB, Shi R, et al., 2021, Spectral characterization and impact of stepwise ablation protocol including LAA electrical isolation on persistent AF, PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, Vol: 44, Pages: 318-326, ISSN: 0147-8389
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- Citations: 1
Boyalla V, Jarman JWE, Markides V, et al., 2021, Internationally validated score to predict the outcome of non-paroxysmal atrial fibrillation ablation: the 'FLAME score', OPEN HEART, Vol: 8, ISSN: 2053-3624
Haldar S, Khan HR, Boyalla V, et al., 2020, Catheter ablation vs. thoracoscopic surgical ablation in long-standing persistent atrial fibrillation: CASA-AF randomized controlled trial., European Heart Journal, Vol: 41, Pages: 4471-4480, ISSN: 0195-668X
AIMS: Long-standing persistent atrial fibrillation (LSPAF) is challenging to treat with suboptimal catheter ablation (CA) outcomes. Thoracoscopic surgical ablation (SA) has shown promising efficacy in atrial fibrillation (AF). This multicentre randomized controlled trial tested whether SA was superior to CA as the first interventional strategy in de novo LSPAF. METHODS AND RESULTS: We randomized 120 LSPAF patients to SA or CA. All patients underwent predetermined lesion sets and implantable loop recorder insertion. Primary outcome was single procedure freedom from AF/atrial tachycardia (AT) ≥30 s without anti-arrhythmic drugs at 12 months. Secondary outcomes included clinical success (≥75% reduction in AF/AT burden); procedure-related serious adverse events; changes in patients' symptoms and quality-of-life scores; and cost-effectiveness. At 12 months, freedom from AF/AT was recorded in 26% (14/54) of patients in SA vs. 28% (17/60) in the CA group [OR 1.128, 95% CI (0.46-2.83), P = 0.83]. Reduction in AF/AT burden ≥75% was recorded in 67% (36/54) vs. 77% (46/60) [OR 1.13, 95% CI (0.67-4.08), P = 0.3] in SA and CA groups, respectively. Procedure-related serious adverse events within 30 days of intervention were reported in 15% (8/55) of patients in SA vs. 10% (6/60) in CA, P = 0.46. One death was reported after SA. Improvements in AF symptoms were greater following CA. Over 12 months, SA was more expensive and provided fewer quality-adjusted life-years (QALYs) compared with CA (0.78 vs. 0.85, P = 0.02). CONCLUSION: Single procedure thoracoscopic SA is not superior to CA in treating LSPAF. Catheter ablation provided greater improvements in symptoms and accrued significantly more QALYs during follow-up than SA. CLINICAL TRIAL REGISTRATION: ISRCTN18250790 and ClinicalTrials.gov: NCT02755688.
Wu J-T, Zaman JAB, Yakupoglu HY, et al., 2020, Catheter Ablation of Atrial Fibrillation in Patients With Functional Mitral Regurgitation and Left Ventricular Systolic Dysfunction, FRONTIERS IN CARDIOVASCULAR MEDICINE, Vol: 7, ISSN: 2297-055X
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- Citations: 7
Gue YX, Kanji R, Markides V, et al., 2020, Angiotensin Converting Enzyme 2 May Mediate Disease Severity In COVID-19, AMERICAN JOURNAL OF CARDIOLOGY, Vol: 130, Pages: 161-162, ISSN: 0002-9149
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- Citations: 6
Shi R, Chen Z, Butcher C, et al., 2020, Diverse activation patterns during persistent atrial fibrillation by noncontact charge-density mapping of human atrium, JOURNAL OF ARRHYTHMIA, Vol: 36, Pages: 692-702, ISSN: 1880-4276
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- Citations: 13
Shi R, Parikh P, Chen Z, et al., 2020, Validation of Dipole Density Mapping During Atrial Fibrillation and Sinus Rhythm in Human Left Atrium, JACC-CLINICAL ELECTROPHYSIOLOGY, Vol: 6, Pages: 171-181, ISSN: 2405-500X
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- Citations: 20
Karim N, Ho SY, Nicol E, et al., 2020, The left atrial appendage in humans: structure, physiology, and pathogenesis, EUROPACE, Vol: 22, Pages: 5-18, ISSN: 1099-5129
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- Citations: 12
Butcher C, Sohaib S, Shun-Shin M, et al., 2019, High Precision Acute Haemodynamic Evaluation of Personalisation of Endocardial Left Ventricular Pacing Site in Patients With Heart Failure, Scientific Sessions of the American-Heart-Association, Publisher: LIPPINCOTT WILLIAMS & WILKINS, ISSN: 0009-7322
Gue YX, Spinthakis N, Markides V, et al., 2019, Patients with atrial fibrillation exhibit a systemic prothrombotic state attributable to impaired endogenous fibrinolysis, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 2948-2948, ISSN: 0195-668X
Shi R, Pope MTB, Boyalla V, et al., 2019, Core to block: a new ablation strategy for treating persistent atrial fibrillation, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 573-573, ISSN: 0195-668X
Karim N, Marinelli A, Cantor E, et al., 2019, Safety of atrial fibrillation catheter ablation in the elderly, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 1775-1775, ISSN: 0195-668X
Shi R, Chen Z, Butcher C, et al., 2019, Diverse activation patterns during persistent atrial fibrillation characterised by dipole density non-contact mapping, Congress of the European-Society-of-Cardiology (ESC) / World Congress of Cardiology, Publisher: OXFORD UNIV PRESS, Pages: 2354-2354, ISSN: 0195-668X
Corden B, Jarman J, Whiffin N, et al., 2019, Association between titin truncating variants and life-threatening cardiac arrhythmias in patients with dilated cardiomyopathy and implantable defibrillator, JAMA Network Open, Vol: 2, Pages: 1-12, ISSN: 2574-3805
Importance There is a need for better arrhythmic risk stratification in nonischemic dilated cardiomyopathy (DCM). Titin-truncating variants (TTNtvs) in the TTN gene are the most common genetic cause of DCM and may be associated with higher risk of arrhythmias in patients with DCM.Objective To determine if TTNtv status is associated with the development of life-threatening ventricular arrhythmia and new persistent atrial fibrillation in patients with DCM and implanted cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) devices.Design, Setting, and Participants This retrospective, multicenter cohort study recruited 148 patients with or without TTNtvs who had nonischemic DCM and ICD or CRT-D devices from secondary and tertiary cardiology clinics in the United Kingdom from February 1, 2011, to June 30, 2016, with a median (interquartile range) follow-up of 4.2 (2.1-6.5) years. Exclusion criteria were ischemic cardiomyopathy, primary valve disease, congenital heart disease, or a known or likely pathogenic variant in the lamin A/C gene. Analyses were performed February 1, 2017, to May 31, 2017.Main Outcome and Measures The primary outcome was time to first device-treated ventricular tachycardia of more than 200 beats/min or first device-treated ventricular fibrillation. Secondary outcome measures included time to first development of persistent atrial fibrillation.Results Of 148 patients recruited, 117 adult patients with nonischemic DCM and an ICD or CRT-D device (mean [SD] age, 56.9 [12.5] years; 76 [65.0%] men; 106 patients [90.6%] with primary prevention indications) were included. Having a TTNtv was associated with a higher risk of receiving appropriate ICD therapy (shock or antitachycardia pacing) for ventricular tachycardia or fibrillation (hazard ratio [HR], 4.9; 95% CI, 2.2-10.7; P < .001). This association was independent of all covariates, including midwall fibrosis measured by late gadolinium enhanc
Khan H, Haldar S, Boyalla V, et al., 2019, Left atrial reverse remodelling is not associated with improved success in treatment of long standing persistent atrial fibrillation, Publisher: OXFORD UNIV PRESS, Pages: 250-250, ISSN: 2047-2404
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