Suture-based techniques versus manual compression for femoral venous haemostasis after electrophysiology procedures.

BACKGROUND AND AIMS: Methods for femoral venous haemostasis following electrophysiology (EP) procedures include manual compression (MC) and suture-based techniques such as a figure-of-eight suture secured with a hand-tied knot (Fo8HT) or a modified figure-of-eight suture secured with a 3-way stopcock (Fo8MOD). We hypothesised that short-term bleeding outcomes using the Fo8MOD approach would be superior to MC. We additionally compared outcomes between Fo8MOD and Fo8HT approaches. METHODS: We studied consecutive patients undergoing EP procedures at our institution between March and December 2023. Patients were categorised into three haemostasis groups: MC, Fo8HT and Fo8MOD. Access site complications were classified as major (requiring intervention or blood transfusion, delaying discharge or resulting in death) or minor (bleeding/haematoma requiring additional compression). RESULTS: 1089 patients were included: MC 718 (65.9%); Fo8HT 105 (9.6%); Fo8MOD 266 (24.4%). Procedures were most commonly for atrial fibrillation (52.4%), atrial flutter (10.9%), and atrioventricular nodal re-entrant tachycardia (10.1%). In patients receiving periprocedural anticoagulation (865, 79.4%), Fo8MOD associated with fewer complications than MC or Fo8HT (major: MC 2.2%, Fo8HT 6.0%, Fo8MOD 0.8%, p = .01; minor: MC 16.5%, Fo8HT 12.0%, Fo8MOD 7.4%, p = .002). In patients not receiving periprocedural anticoagulation, complications did not differ between haemostasis methods (total major and minor complications 5.8%, p = .729 for between groups rates). On multivariable logistic regression, Fo8MOD was associated with a significantly lower risk of access site complications (OR 0.29 [95% CI 0.17-0.48], p < .001), whilst intraprocedural heparinisation (OR 5.25 [2.88-9.69], p < .001) and larger maximal sheath size (OR 1.06 [1.00-1.11], p = .04) were associated with a higher risk of complications. CONCLUSION: Femoral haemostasis with Fo8MOD associates with fewer access site complications than MC and Fo8HT following EP procedures that need periprocedural anticoagulation.

An approach to help differentiate postinfarct scar from borderzone tissue using Ripple Mapping during ventricular tachycardia ablation.

BACKGROUND: Ventricular scar is traditionally highlighted on a bipolar voltage (BiVolt) map in areas of myocardium <0.50 mV. We describe an alternative approach using Ripple Mapping (RM) superimposed onto a BiVolt map to differentiate postinfarct scar from conducting borderzone (BZ) during ventricular tachycardia (VT) ablation. METHODS: Fifteen consecutive patients (left ventricular ejection fraction 30 ± 7%) underwent endocardial left ventricle pentaray mapping (median 5148 points) and ablation targeting areas of late Ripple activation. BiVolt maps were studied offline at initial voltage of 0.50-0.50 mV to binarize the color display (red and purple). RMs were superimposed, and the BiVolt limits were sequentially reduced until only areas devoid of Ripple bars appeared red, defined as RM-scar. The surrounding area supporting conducting Ripple wavefronts in tissue <0.50 mV defined the RM-BZ. RESULTS: RM-scar was significantly smaller than the traditional 0.50 mV cutoff (median 4% vs. 12% shell area, p < .001). 65 ± 16% of tissue <0.50 mV supported Ripple activation within the RM-BZ. The mean BiVolt threshold that differentiated RM-scar from BZ tissue was 0.22 ± 0.07 mV, though this ranged widely (from 0.12 to 0.35 mV). In this study, septal infarcts (7/15) were associated with more rapid VTs (282 vs. 347 ms, p = .001), and had a greater proportion of RM-BZ to RM-scar (median ratio 3.2 vs. 1.2, p = .013) with faster RM-BZ conduction speed (0.72 vs. 0.34 m/s, p = .001). Conversely, scars that supported hemodynamically stable sustained VT (6/15) were slower (367 ± 38 ms), had a smaller proportion of RM-BZ to RM-scar (median ratio 1.2 vs. 3.2, p = .059), and slower RM-BZ conduction speed (0.36 vs. 0.63 m/s, p = .036). RM guided ablation collocated within 66 ± 20% of RM-BZ, most concentrated around the RM-scar perimeter, with significant VT reduction (median 4.0 episodes preablation vs. 0 post, p < .001) at 11 ± 6 months follow-up. CONCLUSION: Postinfarct scars appear significantly smaller than traditional 0.50 mV cut-offs suggest, with voltage thresholds unique to each patient.

Right ventricular stroke work index by echocardiography in adult patients with pulmonary arterial hypertension.

BACKGROUND: In adult patients with pulmonary arterial hypertension (PAH), right ventricular (RV) failure may worsen rapidly, resulting in a poor prognosis. In this population, non-invasive assessment of RV function is challenging. RV stroke work index (RVSWI) measured by right heart catheterization (RHC) represents a promising index for RV function. The aim of the present study was to comprehensively evaluate non-invasive measures to calculate RVSWI derived by echocardiography (RVSWIECHO) using RHC (RVSWIRHC) as a reference in adult PAH patients. METHODS: Retrospectively, 54 consecutive treatment naïve patients with PAH (65 ± 13 years, 36 women) were analyzed. Echocardiography and RHC were performed within a median of 1 day [IQR 0-1 days]. RVSWIRHC was calculated as: (mean pulmonary arterial pressure (mPAP)-mean right atrial pressure (mRAP)) x stroke volume index (SVI)RHC. Four methods for RVSWIECHO were evaluated: RVSWIECHO-1 = Tricuspid regurgitant maximum pressure gradient (TRmaxPG) x SVIECHO, RVSWIECHO-2 = (TRmaxPG-mRAPECHO) x SVIECHO, RVSWIECHO-3 = TR mean gradient (TRmeanPG) x SVIECHO and RVSWIECHO-4 = (TRmeanPG-mRAPECHO) x SVIECHO. Estimation of mRAPECHO was derived from inferior vena cava diameter. RESULTS: RVSWIRHC was 1132 ± 352 mmHg*mL*m-2. In comparison with RVSWIRHC in absolute values, RVSWIECHO-1 and RVSWIECHO-2 was significantly higher (p < 0.001), whereas RVSWIECHO-4 was lower (p < 0.001). No difference was shown for RVSWIECHO-3 (p = 0.304). The strongest correlation, with RVSWIRHC, was demonstrated for RVSWIECHO-2 (r = 0.78, p < 0.001) and RVSWIECHO-1 ( r = 0.75, p < 0.001). RVSWIECHO-3 and RVSWIECHO-4 had moderate correlation (r = 0.66 and r = 0.69, p < 0.001 for all). A good agreement (ICC) was demonstrated for RVSWIECHO-3 (ICC = 0.80, 95% CI 0.64-0.88, p < 0.001), a moderate for RVSWIECHO-4 (ICC = 0.73, 95% CI 0.27-0.87, p < 0.001) and RVSWIECHO-2 (ICC = 0.55, 95% CI - 0.21-0.83, p < 0.001). A poor ICC was demonstrated for RVSWIECHO-1 (ICC = 0.45, 95% CI - 0.18-0.77, p < 0.001). Agreement of absolute values for RVSWIECHO-1 was - 772 ± 385 (- 50 ± 20%) mmHg*mL*m-2, RVSWIECHO-2 - 600 ± 339 (-41 ± 20%) mmHg*mL*m-2, RVSWIECHO-3 42 ± 286 (5 ± 25%) mmHg*mL*m-2 and for RVSWIECHO-4 214 ± 273 (23 ± 27%) mmHg*mL*m-2. CONCLUSION: The correlation with RVSWIRHC was moderate to strong for all echocardiographic measures, whereas only RVSWIECHO-3 displayed high concordance of absolute values. The results, however, suggest that RVSWIECHO-1 or RVSWIECHO-3 could be the preferable echocardiographic methods. Prospective studies are warranted to evaluate the clinical utility of such measures in relation to treatment response, risk stratification and prognosis in patients with PAH.

Right ventricular function parameters in pulmonary hypertension: echocardiography vs. cardiac magnetic resonance.

BACKGROUND: Right ventricular (RV) function is a major determinant of outcome in patients with pulmonary hypertension. Cardiac magnetic resonance (CMR) is gold standard to assess RV ejection fraction (RVEFCMR), however this is a crude measure. New CMR measures of RV function beyond RVEFCMR have emerged, such as RV lateral atrio-ventricular plane displacement (AVPDlat), maximum emptying velocity (S'CMR), RV fractional area change (FACCMR) and feature tracking of the RV free wall (FWSCMR). However, it is not fully elucidated if these CMR measures are in parity with the equivalent echocardiography-derived measurements: tricuspid annular plane systolic excursion (TAPSE), S'-wave velocity (S'echo), RV fractional area change (FACecho) and RV free wall strain (FWSecho). The aim of this study was to compare regional RV function parameters derived from CMR to their echocardiographic equivalents in patients with pulmonary hypertension and to RVEFCMR. METHODS: Fifty-five patients (37 women, 62 ± 15 years) evaluated for pulmonary hypertension underwent CMR and echocardiography. AVPDlat, S'CMR, FACCMR and FWSCMR from cine 4-chamber views were compared to corresponding echocardiographic measures and to RVEFCMR delineated in cine short-axis stack. RESULTS: A strong correlation was demonstrated for FAC whereas the remaining measurements showed moderate correlation. The absolute bias for S' was 2.4 ± 3.0 cm/s (relative bias 24.1 ± 28.3%), TAPSE/AVPDlat 5.5 ± 4.6 mm (33.2 ± 25.2%), FWS 4.4 ± 5.8% (20.2 ± 37.5%) and for FAC 5.1 ± 8.4% (18.5 ± 32.5%). In correlation to RVEFCMR, FACCMR and FWSecho correlated strongly, FACecho, AVPDlat, FWSCMR and TAPSE moderately, whereas S' had only a weak correlation. CONCLUSION: This study has demonstrated a moderate to strong correlation of regional CMR measurements to corresponding echocardiographic measures. However, biases and to some extent wide limits of agreement, exist between the modalities. Consequently, the equivalent measures are not interchangeable at least in patients with pulmonary hypertension. The echocardiographic parameter that showed best correlation with RVEFCMR was FWSecho. At present, FACecho and FWSecho as well as RVEFCMR are the preferred methods to assess and follow up RV function in patients with pulmonary hypertension. Future investigations of the CMR right ventricular measures, beyond RVEF, are warranted.

Systematic re-evaluation of SCN5A variants associated with Brugada syndrome.

BACKGROUND: A large number of SCN5A variants have been reported to underlie Brugada syndrome (BrS). However, the evidence supporting individual variants is highly heterogeneous. OBJECTIVE: We systematically re-evaluated all SCN5A variants reported in BrS using the 2015 American college of medical genetics and genomics and the association for molecular pathology (ACMG-AMP) guidelines. METHODS: A PubMed/Embase search was performed to identify all reported SCN5A variants in BrS. Standardized bioinformatic re-analysis (SIFT, PolyPhen, Mutation Taster, Mutation assessor, FATHMM, GERP, PhyloP, and SiPhy) and re-evaluation of frequency in the gnomAD database were performed. Fourteen ACMG-AMP rules were deemed applicable for SCN5A variant analysis. RESULTS: Four hundred and eighty unique SCN5A variants were identified, the majority of which 425 (88%) were coding variants. One hundred and fifty-six of 425 (37%) variants were classified as pathogenic/likely pathogenic. Two hundred and fifty-eight (60%) were classified as variants of uncertain significance, while a further 11 (3%) were classified as benign/likely benign. When considering the subset of variants that were considered "null" variants separately, 95% fulfilled criteria for pathogenicity/likely pathogenicity. In contrast, only 17% of missense variants fulfilled criteria for pathogenicity/likely pathogenicity. Importantly, however, only 25% of missense variants had available functional data, which was a major score driver for pathogenic classification. CONCLUSION: Based on contemporary ACMG-AMP guidelines, only a minority of SCN5A variants implicated in BrS fulfill the criteria for pathogenicity or likely pathogenicity.

Early experience of thoracoscopic vs. catheter ablation for atrial fibrillation.

AIMS: Video-assisted thoracoscopic surgery (VATS) ablation has been advocated as a treatment option for non-paroxysmal atrial fibrillation (AF) in recent guidelines. Real-life data on its safety and efficacy during a centre's early experience are sparse. METHODS AND RESULTS: Thirty patients (28 persistent/longstanding persistent AF) underwent standalone VATS ablation for AF by an experienced thoracoscopic surgeon, with the first 20 cases proctored by external surgeons. Procedural and follow-up outcomes were collected prospectively, and compared with 90 propensity-matched patients undergoing contemporaneous catheter ablation (CA). Six (20.0%) patients undergoing VATS ablation experienced ≥1 major complication (death n = 1, stroke n = 2, conversion to sternotomy n = 3, and phrenic nerve injury n = 2). This was significantly higher than the 1.1% major complication rate (tamponade requiring drainage n = 1) seen with CA (P < 0.001). Twelve-month single procedure arrhythmia-free survival rates without antiarrhythmic drugs were 56% in the VATS and 57% in the CA cohorts (P = 0.22), and 78% and 80%, respectively given an additional CA and antiarrhythmic drugs (P = 0.32). CONCLUSION: During a centre's early experience, VATS ablation may have similar success rates to those from an established CA service, but carry a greater risk of major complications. Those embarking on a programme of VATS AF ablation should be aware that complication and success rates may differ from those reported by selected high-volume centres.

Same-day discharge in selected patients undergoing atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) ablation is a complex procedure, generally requiring at least one overnight hospital stay. We investigated the safety and feasibility of early mobilization and same-day discharge following streamlined peri-ablation management for AF. METHODS: From 2014, we offered same-day discharge to selected patients who underwent uncomplicated AF ablation on the morning lists, with ultrasound-guided femoral access, uninterrupted warfarin or minimal interruption in novel oral anticoagulants, and reversal of intraprocedural heparin with protamine. Patients were discharged 6-8 h postprocedure and offered access to a dedicated nurse helpline. RESULTS: Of 1599 AF ablation cases performed from April 2014 to March 2017, 811 (50.7%) were performed on the morning lists and 169/811 (20.8%) were discharged on the same day. Excluding 26 research cases, 1/143 (0.7%) had transient right phrenic nerve palsy and five (3.5%) cases experienced minor problems that did not preclude same-day discharge; three (2.1%) needed rehospitalization postdischarge: one for pericarditic chest pain and two for nausea/vomiting. Compared to 642 overnight cases, day-case procedures were shorter, more likely to be redos, to be performed under sedation rather than general anesthesia, and less likely to involve linear lesions and electrical cardioversion. There were no significant differences in patient age, gender, body mass index, CHA2 DS2 -VASc, in preprocedural anticoagulation regimen (warfarin vs novel anticoagulants vs no anticoagulation) and in choice of ablation method (cryoballoon vs radiofrequency). CONCLUSIONS: Selective same-day discharge after AF ablation is safe and feasible using a streamlined peri-procedural care protocol. Wider adoption can potentially reduce health-care costs while improving patient experience.

Demonstration of pulmonary vein exit block following pulmonary vein isolation: A novel use for adenosine.

INTRODUCTION: Demonstration of exit block after pulmonary vein isolation (PVI) is the cornerstone of ablation for atrial fibrillation (AF). It requires the demonstration of local pulmonary vein (PV) capture and absence of conduction to the atrium but is often challenging due to the inability to see local paced PV-evoked potentials. We retrospectively examined the ability of adenosine to augment this technique during CARTO-based radiofrequency ablation procedures. METHODS: Retrospective analysis of evoked PV potentials during adenosine administration while testing for PV exit block at a single UK center. RESULTS: One hundred and twenty-nine PVs in 33 patients were isolated using radiofrequency energy to demonstrate entry block. Of those, the pacing of 24 veins under baseline conditions did not clearly demonstrate local PV-evoked potentials sufficient to be sure that the local vein was truly captured and dissociated from the atrium. Adenosine was administered in 19 of these, with 10 of 19 (52.6%) veins then demonstrating clear local PV-evoked potentials transiently during adenosine administration, sufficient to allow assessment of definite exit block. CONCLUSION: Adenosine administered during PV pacing allows transient visualization of local PV-evoked potentials after PVI facilitating the clearer demonstration of PV exit block in over 50% veins.

Ablation index, a novel marker of ablation lesion quality: prediction of pulmonary vein reconnection at repeat electrophysiology study and regional differences in target values.

AIMS: Force-Time Integral (FTI) is commonly used as a marker of ablation lesion quality during pulmonary vein isolation (PVI), but does not incorporate power. Ablation Index (AI) is a novel lesion quality marker that utilizes contact force, time, and power in a weighted formula. Furthermore, only a single FTI target value has been suggested despite regional variation in left atrial wall thickness. We aimed to study AI's and FTI's relationships with PV reconnection at repeat electrophysiology study, and regional threshold values that predicted no reconnection. METHODS AND RESULTS: Forty paroxysmal atrial fibrillation patients underwent contact force-guided PVI, and the minimum and mean AI and FTI values for each segment were identified according to a 12-segment model. All patients underwent repeat electrophysiology study at 2 months, regardless of symptoms, to identify sites of PV reconnection. Late PV reconnection was seen in 53 (11%) segments in 25 (62%) patients. Reconnected segments had significantly lower minimum AI [308 (252-336) vs. 373 (323-423), P < 0.0001] and FTI [137 (92-182) vs. 228 (157-334), P < 0.0001] compared with non-reconnected segments. Minimum AI and FTI were both independently predictive, but AI had a smaller P value. Higher minimum AI and FTI values were required to avoid reconnection in anterior/roof segments than for posterior/inferior segments (P < 0.0001). No reconnection was seen where the minimum AI value was ≥370 for posterior/inferior segments and ≥480 for anterior/roof segments. CONCLUSION: The minimum AI value in a PVI segment is independently predictive of reconnection of that segment at repeat electrophysiology study. Higher AI and FTI values are required for anterior/roof segments than for posterior/inferior segments to prevent reconnection.

Reablated Sites of Acute Reconnection After Pulmonary Vein Isolation Do Not Predict Sites of Late Reconnection at Repeat Electrophysiology Study.

INTRODUCTION: Acute reconnection of pulmonary veins (PVs) is frequently seen in the waiting period following pulmonary vein isolation (PVI). There are concerns that reablation at these sites may not be durably effective due to tissue edema caused by the initial ablation. We aimed to prospectively study the relationship between acute and late reconnection. METHODS AND RESULTS: Wide-area circumferential PVI was performed in 40 paroxysmal AF patients. Spontaneous reconnection was assessed after a minimum 20-minute waiting period, with adenosine administered to unmask dormant reconnection. All sites of acute reconnection were ablated to reisolate the PV. All 40 patients then underwent repeat electrophysiology study after 2 months, regardless of symptoms, to identify late reconnection. Sites of acute and late reconnection were compared according to a 12-segment PVI model. Acute reconnection was seen in 28 (6%) PVI segments in 20 (50%) patients, affecting 24/160 (15%) PVs. All were successfully reisolated. At repeat electrophysiology study, 51 (11%) PVI segments were reconnected in 25 (62%) patients, affecting 41 (25%) PVs. The proportion of PVI segments with and without acute reconnection exhibiting late reconnection at repeat study was no different (14% vs. 10%, P = 0.524). There was also no difference in late reconnection between PVI circles or patients with and without acute reconnection. CONCLUSION: Most PVI segments that undergo further ablation for acute reconnection show persistent isolation at repeat electrophysiology study, and the rate of late reconnection for these segments is no different to that for segments that did not acutely reconnect. This implies that effective reablation is delivered at these sites.

A novel marker to predict early recurrence after atrial fibrillation ablation: the ablation effectiveness quotient.

INTRODUCTION: Inability to predict clinical outcome despite acutely successful pulmonary vein isolation (PVI) remains the Achilles' heel of atrial fibrillation ablation (AFA). Arrhythmia recurrence is frequently due to recovery of radiofrequency (RF) ablation lesions believed to be complete at the original procedure. OBJECTIVES: We hypothesized that a high ratio between post-AFA levels of serum high sensitivity cardiac troponin T (HScTnT), a highly specific marker of acute myocardial injury, and duration of RF application (the ablation effectiveness quotient, AEQ) would indicate effective ablation and correlate with early clinical success. METHODS: We prospectively measured HScTnT levels in 60 patients (42 [70%] male, 22 [37%] with paroxysmal AF [PAF], mean age 62.5 ± 10.6 years) 12-18 hours after AFA and calculated the AEQ for each. Patients were followed-up with ECGs and Holter monitors for recurrence of atrial tachyarrhythmia (AT). RESULTS: Early recurrence of AT within 6 months occurred in 22 (37%). AT recurrence was not significantly related to left atrial size or comorbidities, nor to RF time or HScTnT level. Mean AEQ was significantly lower in those with recurrence than those without (0.35 ± 0.14 ng/L/s vs. 0.45 ± 0.18 ng/L/s), P = 0.02. Subgroup analysis showed this finding was due to patients with PAF in whom early significance was maintained to one year, with an AEQ >0.4 ng/L/s having 75% sensitivity and 90% specificity in predicting freedom from AT. CONCLUSION: A high AEQ correlates well with freedom from AT in patients with PAF in both the short and medium term. If confirmed in further studies, AEQ may become a useful marker of risk of AT post-AFA.

Improving safety in catheter ablation for atrial fibrillation: a prospective study of the use of ultrasound to guide vascular access.

INTRODUCTION: The most frequent complications of AF ablation (AFA) are related to vascular access, but there is little evidence as to how these can be minimized. METHODS: Consecutive patients undergoing AFA at a high-volume center received either standard care (Group S) or routine ultrasound-guided vascular access (Group U). Vascular complications were assessed before hospital discharge and by means of postal questionnaire 1 month later. Outcome measures were BARC 2+ bleeding complications, postprocedural pain, and prolonged bruising. RESULTS: Patients in Group S (n = 146) and U (n = 163) were well matched at baseline. Follow-up questionnaires were received from 92.6%. Patients in Group U were significantly less likely to have a BARC 2+ bleed, 10.4% versus 19.9% P = 0.02, were less likely to suffer groin pain after discharge (27.1% vs. 42.8%; P = 0.006) and were less likely to experience prolonged local bruising (21.5% vs. 40.4%; P = 0.001). Multivariable logistic regression analysis revealed a significant association of vascular complications with nonultrasound guided access (OR 3.12 95%CI 1.54-5.34; P = 0.003) and increasing age (OR 1.05 95%CI 1.01-1.09; P = 0.02). CONCLUSION: Routine use of ultrasound-guided vascular access for AFA is associated with a significant reduction in bleeding complications, postprocedural pain, and prolonged bruising when compared to standard care.

Cost, efficiency, and outcomes of pulsed field ablation vs thermal ablation for atrial fibrillation: A real-world study.

BACKGROUND: With the exponential growth of catheter ablation for atrial fibrillation (AF), there is increasing interest in associated health care costs. Pulsed field ablation (PFA) using a single-shot pentaspline multielectrode catheter has been shown to be safe and effective for AF ablation, but its cost efficiency compared to conventional thermal ablation modalities (cryoballoon [CB] or radiofrequency [RF]) has not been evaluated. OBJECTIVE: The purpose of this study was to compare cost, efficiency, effectiveness, and safety between PFA, CB, and RF for AF ablation. METHODS: We studied 707 consecutive patients (PFA: 208 [46.0%]; CB: 325 [29.4%]; RF: 174 [24.6%]) undergoing first-time AF ablation. Individual procedural costs were calculated, including equipment, laboratory use, and hospital stay, and compared between ablation modalities, as were effectiveness and safety. RESULTS: Skin-to-skin times and catheter laboratory times were significantly shorter with PFA (68 and 102 minutes, respectively) than with CB (91 and 122 minutes) and RF (89 and 123 minutes) (P < .001). General anesthesia use differed across modalities (PFA 100%; CB 10.2%; RF 61.5%) (P < .001). Major complications occurred in 1% of cases, with no significant differences between modalities. Shorter procedural times resulted in lower staffing and laboratory costs with PFA, but these savings were offset by substantially higher equipment costs, resulting in higher overall median costs with PFA (£10,010) than with CB (£8106) and RF (£8949) (P < .001). CONCLUSION: In this contemporary real-world study of the 3 major AF ablation modalities used concurrently, PFA had shorter skin-to-skin and catheter laboratory times than did CB and RF, with similarly low rates of complications. However, PFA procedures were considerably more expensive, largely because of higher equipment cost.

Silent pulmonary veins at redo ablation for atrial fibrillation: Implications and approaches.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Despite promising success rates, redo ablation is sometimes required. At redo, PVs may be found to be isolated (silent) or reconnected. We studied patients with silent vs reconnected PVs at redo and analysed associations with adverse outcomes. METHODS: Patients undergoing redo AF ablations between 2013 and 2019 at our institution were included and stratified into silent PVs or reconnected PVs. The primary outcome was a composite of further redo ablation, non-AF ablation, atrioventricular nodal ablation, and death. Secondary outcomes included arrhythmia recurrence. RESULTS: A total of 467 patients were included with mean 4.6 ± 1.7 years follow-up, of whom 48 (10.3%) had silent PVs. The silent PV group had had more often undergone >1 prior ablation (45.8% vs 9.8%; p<0.001), had more persistent AF (62.5% vs 41.1%; p=0.005) and had more non-PV ablation performed both at prior ablation procedures and at the analysed redo ablation. The primary outcome occurred more frequently in those with silent PVs (25% vs 13.8%; p=0.053). Arrhythmia recurrence was also more common in the silent PV group (66.7% vs 50.6%; p=0.047). After multivariable adjustment, female sex (aHR 2.35 [95% CI 2.35-3.96]; p=0.001) and ischaemic heart disease (aHR 3.21 [95% CI 1.56-6.62]; p=0.002) were independently associated with the primary outcome, and left atrial enlargement (aHR 1.58 [95% CI 1.20-2.08]; p=0.001) and >1 prior ablation (aHR 1.88 [95% CI 1.30-2.72]; p<0.001) were independently associated with arrhythmia recurrence. Whilst a finding of silent PVs was not itself significant after multivariable adjustment, this provides an easily assessable parameter at clinically indicated redo ablation which informs the clinician of the likelihood of a worse future prognosis. CONCLUSIONS: Patients with silent PVs at redo AF ablation have worse clinical outcomes.

Delineating postinfarct ventricular tachycardia substrate with dynamic voltage mapping in areas of omnipolar vector disarray.

Background: Defining postinfarct ventricular arrhythmic substrate is challenging with voltage mapping alone, though it may be improved in combination with an activation map. Omnipolar technology on the EnSite X system displays activation as vectors that can be superimposed onto a voltage map. Objective: The study sought to optimize voltage map settings during ventricular tachycardia (VT) ablation, adjusting them dynamically using omnipolar vectors. Methods: Consecutive patients undergoing substrate mapping were retrospectively studied. We categorized omnipolar vectors as uniform when pointing in one direction, or in disarray when pointing in multiple directions. We superimposed vectors onto voltage maps colored purple in tissue >1.5 mV, and the voltage settings were adjusted so that uniform vectors appeared within purple voltages, a process termed dynamic voltage mapping (DVM). Vectors in disarray appeared within red-blue lower voltages. Results: A total of 17 substrate maps were studied in 14 patients (mean age 63 ± 13 years; mean left ventricular ejection fraction 35 ± 6%, median 4 [interquartile range 2-8.5] recent VT episodes). The DVM mean voltage threshold that differentiated tissue supporting uniform vectors from disarray was 0.27 mV, ranging between patients from 0.18 to 0.50 mV, with good interobserver agreement (median difference: 0.00 mV). We found that VT isthmus components, as well as sites of latest activation, isochronal crowding, and excellent pace maps colocated with tissue along the DVM border zone surrounding areas of disarray. Conclusion: DVM, guided by areas of omnipolar vector disarray, allows for individualized postinfarct ventricular substrate characterization. Tissue bordering areas of disarray may harbor greater arrhythmogenic potential.

Predictors of the need for atrioventricular nodal ablation following redo ablation for atrial fibrillation.

Background: Patients who have recurrent atrial fibrillation (AF) following redo catheter ablation may eventually be managed with a pace-and-ablate approach, involving pacemaker implant followed by atrioventricular nodal ablation (AVNA). We sought to determine which factors would predict subsequent AVNA in patients undergoing redo AF ablation. Methods: We analyzed patients undergoing redo AF ablations between 2013 and 2019 at our institution. Follow-up was censored on December 31, 2021. Patients with no available follow-up data were excluded. Time-to-event analysis with Cox proportional hazard regression was used to compare those who underwent AVNA to those who did not. Results: A total of 467 patients were included, of whom 39 (8.4%) underwent AVNA. After multivariable adjustment, female sex (aHR 4.68 [95% CI 2.30-9.50]; p < 0.001), ischemic heart disease (aHR 2.99 [95% CI 1.25-7.16]; p = 0.014), presence of a preexisting pacemaker (aHR 3.25 [95% CI 1.10-9.60]; p = 0.033), and persistent AF (aHR 2.22 [95% CI 1.07-4.59]; p = 0.032) were associated with increased risk of subsequent AVNA requirement. Conclusion: Female sex, ischemic heart disease, and persistent AF may be useful clinical predictors of the requirement for subsequent AVNA and may be considered as part of shared clinical decision making.

Incidence of vascular complications for electrophysiology procedures in the ultrasound era: a single-centre experience over 10,000 procedures in the long term.

BACKGROUND: Ultrasound (US) is being increasingly used to guide vascular access for electrophysiology (EP) procedures in many centres. Nonetheless, the incidence and predictors of vascular complications in the US era are limited. In this study, we describe our experience of vascular access-related complications associated with EP procedures which were performed with the routine use of US-guided vascular access. METHODS: A total of 10,158 consecutive EP procedures in 8361 patients performed from April 2014 (when our centre moved to a policy of routine US-guided vascular access for EP procedures) to March 2022 were included. The outcome of interest was any vascular access-related complication that occurred within 7 days of the procedure; these were classified as severe if surgical intervention and/or blood transfusion was required, major if non-surgical intervention or delayed hospital discharge was required, or minor if it did not fulfil the criteria for severe or major. RESULTS: During the study period, 2 (0.02%) severe vascular complications occurred, including 1 pseudo-aneurysm requiring surgery and 1 retroperitoneal haemorrhage requiring blood transfusion. Nine (0.09%) major complications occurred, including 6 hematomas managed by compression devices, 1 type B aortic dissection, 1 AV fistula managed conservatively and 1 haematoma managed conservatively but delayed hospital discharge. Eighteen (0.18%) minor haematomas were seen that did not require any intervention or delayed hospital discharge. On multivariable analysis, female sex [OR (95% CI): 2.5 (1.2, 5.4)] and use of an arterial access [OR (95% CI): 19.3 (7.1, 52.3)] were seen to be independent predictors of the 29 vascular complications. CONCLUSION: With the use of US-guided vascular access in EP procedures, major vascular complications are exceedingly rare, particularly those needing surgical intervention. Our results provide additional evidence for scientific guidelines to support US use.

Impact of bridging with left ventricular assist device on right ventricular function following heart transplantation.

AIMS: Patients awaiting orthotopic heart transplantation (OHT) can be bridged utilizing a left ventricular assist device (LVAD) that reduces left ventricular filling pressures, decreases pulmonary artery wedge pressure, and maintains adequate cardiac output. This study set out to examine the poorly investigated area of if and how pre-treatment with LVAD impacts right ventricular (RV) function following OHT. METHODS AND RESULTS: We prospectively evaluated 59 (LVAD n = 20) consecutive OHT patients. Transthoracic echocardiography (TTE) was performed in conjunction with right heart catheterization (RHC) at 1, 6, and 12 months after OHT. RV function TTE-parameters included tricuspid annular plane systolic excursion (TAPSE), systolic tissue velocity (S'), fractional area change, two-dimensional RV global longitudinal strain and longitudinal strain from the RV lateral wall (RVfree). At 1 month after OHT, the LVAD group had significantly better longitudinal RV function than the non-LVAD group: TAPSE (15 ± 3 mm vs. 12 ± 2 mm, P < 0.001), RV global longitudinal strain (-19.8 ± 2.1% vs. -14.3 ± 2.8%, P < 0.001), and RVfree (-19.8 ± 2.3% vs. -14.1 ± 2.9%, P < 0.001). At this time point, pulmonary vascular resistance (PVR) was also lower [1.2 ± 0.4 Wood Units (WU) vs. 1.6 ± 0.6 WU, P < 0.05] in the LVAD group compared with the non-LVAD group. At 6 and 12 months, no difference was detected in any of the TTE and RHC measured parameters between the two groups. Between 1 and 12 months, all parameters of RV function improved significantly in the non-LVAD group but remained unaltered in the LVAD group. CONCLUSIONS: Our results indicate that pre-treatment with LVAD decreases PVR and is associated with significantly better RV function early following OHT. During the first year following transplantation, RV function progressively improved in the non-LVAD group such that at 6 and 12 months, no difference in RV function was detected between the groups.

Impact of COVID-19 on patients awaiting ablation for atrial fibrillation.

OBJECTIVE: Atrial fibrillation (AF) ablation services were significantly affected by the COVID-19 pandemic. We aimed to evaluate a symptom-based clinician prioritisation scheme for waiting list management compared with patient-completed quality of life (QoL) scores. We also sought to understand factors influencing QoL, particularly the impact of COVID-19, on patients awaiting AF ablation, via a bespoke questionnaire. METHODS: Patients awaiting AF ablation were sent two QoL questionnaires (Atrial Fibrillation Effect on QualiTy of Life (AFEQT) and EuroQol 5D (EQ5D-5L)) and the bespoke questionnaire. At a separate time point, patients were categorised as C1-urgent, C2-priority or C3-routine by their cardiologist based on review of clinic letters. RESULTS: There were 118 patients included with priority categorisation available for 86 patients. Median AFEQT scores were lower in C2 (30.4; 17.2-51.9) vs C3 patients (56.5; 32.1-74.1; p<0.01). Unplanned admission occurred in 3 patients in C3 with AFEQT scores of <40. Although 65 patients had AF symptoms during the pandemic, 43.1% did not seek help where they ordinarily would have. An exercise frequency of ≥3-4 times a week was associated with higher AFEQT (56.5; 41.2-74.1; p<0.001) and EQ5D (0.84; 0.74-0.88; p<0.0001) scores. CONCLUSION: The QoL of patients awaiting AF ablation is impaired and AFEQT helps to identify patients at risk of admission, over and above physician assessment. COVID-19 influenced patients seeking medical attention with symptomatic AF when they normally would. Regular exercise is associated with better QoL in patients awaiting AF ablation.

Echocardiographic assessment of chamber size and ventricular function during the first year after heart transplantation.

AIMS: Detecting changes in ventricular function after orthotopic heart transplantation (OHT) using transthoracic echocardiography (TTE) is important but interpretation of findings is complicated by lack of data on early graft adaptation. We sought to evaluate echocardiographic measures of ventricular size and function the first year following OHT including speckle tracking derived strain. We also aimed to compare echocardiographic findings to haemodynamic parameters obtained by right heart catheterization (RHC). METHODS AND RESULTS: Fifty OHT patients were examined prospectively with TTE and RHC at 1, 6, and 12 months after OHT. Left ventricle (LV) was assessed with fractional shortening, ejection fraction and systolic tissue velocities. Right ventricular (RV) evaluation included tricuspid annular plane systolic excursion (TAPSE), systolic tissue velocity (S´) and fractional area change (FAC). LV global longitudinal and circumferential strain and RV global longitudinal strain (GLS) and RV lateral wall strain (RVfree) were analysed. No relevant changes occurred in LV echocardiographic parameters, whereas all measures of RV function improved significantly during follow-up. There was an increase in TAPSE (12.4 ± 3.3 mm to 14.4 ± 4.3 mm, p < .01), FAC (36% ± 8% to 41% ± 8%, p < .01), RV GLS (-15.8% ± 4% to -17.8% ± 3.6%, p < .01), and RVfree (-15.5% ± 3.7% to -18.6% ± 3.6%, p < .001). Between 1 and 12 months, pulmonary pressures decreased, whereas pulmonary vascular resistance did not. CONCLUSION: Stable OHT recipients reached steady state regarding LV function 1 month after transplantation. In contrast, RV function displayed gradual improvement the first year following OHT, indicating delayed RV adaptation as compared to the LV. Improved RV function parameters were independent of invasively measured pulmonary pressures.