Periprocedural acute haemodynamic decompensation during substrate-based ablation of scar-related ventricular tachycardia: a rare and unpredictable event.

AIMS: Patients with structural heart disease (SHD) undergoing catheter ablation (CA) for ventricular tachycardia (VT) are at considerable risk of periprocedural complications, including acute haemodynamic decompensation (AHD). The PAINESD score was proposed to predict the risk of AHD. The goal of this study was to validate the PAINESD score using the retrospective analysis of data from a large-volume heart centre. METHODS AND RESULTS: Patients who had their first radiofrequency CA for SHD-related VT between August 2006 and December 2020 were included in the study. Procedures were mainly performed under conscious sedation. Substrate mapping/ablation was performed primarily during spontaneous rhythm or right ventricular pacing. A purposely established institutional registry for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated using the source medical records. Acute haemodynamic decompensation triggered by CA procedure was defined as intraprocedural or early post-procedural (<12 h) development of acute pulmonary oedema or refractory hypotension requiring urgent intervention. The study cohort consisted of 1124 patients (age, 63 ± 13 years; males, 87%; ischaemic cardiomyopathy, 67%; electrical storm, 25%; New York Heart Association Class, 2.0 ± 1.0; left ventricular ejection fraction, 34 ± 12%; diabetes mellitus, 31%; chronic obstructive pulmonary disease, 12%). Their PAINESD score was 11.4 ± 6.6 (median, 12; interquartile range, 6-17). Acute haemodynamic decompensation complicated the CA procedure in 13/1124 = 1.2% patients and was not predicted by PAINESD score with AHD rates of 0.3, 1.8, and 1.1% in subgroups by previously published PAINESD terciles (<9, 9-14, and >14). However, the PAINESD score strongly predicted mortality during the follow-up. CONCLUSION: Primarily substrate-based CA of SHD-related VT performed under conscious sedation is associated with a substantially lower rate of AHD than previously reported. The PAINESD score did not predict these events. The application of the PAINESD score to the selection of patients for pre-emptive mechanical circulatory support should be reconsidered.

Autonomic Changes Are More Durable After Radiofrequency Than Pulsed Electric Field Pulmonary Vein Ablation.

BACKGROUND: Pulmonary vein isolation (PVI) by radiofrequency (RF) energy is associated with a collateral ganglionated plexi ablation. Pulsed electric field (PEF) is a nonthermal energy source that preferentially affects the myocardial cells and spares neural tissue. OBJECTIVES: This study investigated whether PVI by a PEF compared with RF energy will result in less prominent alteration of the cardiac autonomic nervous system. METHODS: A total of 31 patients with atrial fibrillation underwent PVI using a novel lattice-tip catheter and PEF energy (n = 18) or a conventional irrigated-tip catheter and RF energy (n = 13). The response of the sinoatrial node and atrioventricular node to extracardiac high-frequency, high-output, right vagal nerve stimulation was evaluated at baseline and during and at the end of the ablation procedure. Substantial reduction in responsiveness was arbitrarily defined as stimulation-inducible pause <1.5 seconds. RESULTS: Reduced response of the sinoatrial node was documented in 13 of 13 (100%) and 6 of 18 (33%) patients (P = 0.0001) in RF and PEF groups, respectively. Reduced response of the atrioventricular node was found in 10 of 11 (93%) and 6 of 18 (33%) patients (P = 0.002) in RF and PEF groups, respectively. The major effects were observed predominantly during ablation around the right pulmonary veins. Early recovery of ganglionated plexi function was noticed only in the PEF ablation group. RF ablation resulted in higher acceleration of the sinus rhythm compared with PEF ablation (20 ± 13 beats/min vs 12 ± 10 beats/min; P = 0.04). CONCLUSIONS: PEF compared with RF energy used for PVI induces significantly weaker and less durable suppression of cardiac autonomic regulations.

Gender differences in major vascular complications of catheter ablation for atrial fibrillation.

AIMS: Catheter ablation (CA) for atrial fibrillation (AF) has a considerable risk of procedural complications. Major vascular complications (MVCs) appear to be the most frequent. This study investigated gender differences in MVCs in patients undergoing CA for AF in a high-volume tertiary center. METHODS: A total of 4734 CAs for AF (65% paroxysmal, 26% repeated procedures) were performed at our center between January 2006 and August 2018. Patients (71% males) aged 60 ± 10 years and had a body mass index of 29 ± 4 kg/m2 at the time of the procedure. Radiofrequency point-by-point ablation was employed in 96.3% of procedures with the use of three-dimensional navigation systems and facilitated by intracardiac echocardiography. Pulmonary vein isolation was mandatory; cavotricuspid isthmus and left atrial substrate ablation were performed in 22% and 38% procedures, respectively. MVCs were defined as those that resulted in permanent injury, required intervention, or prolonged hospitalization. Their rates and risk factors were compared between genders. RESULTS: A total of 112 (2.4%) MVCs were detected: 54/1512 (3.5%) in females and 58/3222 (1.8%) in males (p < .0001). On multivariate analysis, lower body height was the only risk factor for MVCs in females (p = .0005). On the contrary, advanced age was associated with MVCs in males (p = .006). CONCLUSION: Females have a higher risk of MVCs following CA for AF compared to males. This difference is driven by lower body size in females. Low body height in females and advanced age in males are independent predictors of MVCs. Ultrasound-guided venipuncture lowered the MVC rate in males.

Impact of access route to the left ventricle on asymptomatic periprocedural brain injury: the results of a randomized trial in patients undergoing catheter ablation of ventricular tachycardia.

AIMS: Catheter ablation of ventricular tachycardia (VT) is an effective treatment in patients with structural heart disease (SHD) and recurrent arrhythmias. However, the procedure is associated with the risk of complications, including both manifest and asymptomatic cerebral thromboembolic events. We hypothesized that periprocedural asymptomatic brain injury (ABI) can be reduced by using transseptal instead of the retrograde access route to the left ventricle (LV). METHODS AND RESULTS: Consecutive patients undergoing VT ablation for SHD were randomized 1:1 to either retrograde or transseptal LV access. All patients underwent radiofrequency ablation in conscious sedation with the use of an irrigated tip catheter. The degree of brain damage was evaluated by serum level of biomarker S100B. Significant ABI was defined as a post-ablation relative increase of S100B level >30%. A total of 144 patients (66 ± 9 years; 14 females; 90% coronary artery disease; LV ejection fraction: 30 ± 8%) were enrolled and 72 were allocated to each study groups. Symptomatic neurological complication of the procedure was not observed in any subject. A significant ABI was detected in 19.4% of patients. It was more commonly observed in subjects randomized to retrograde vs. transseptal LV access (26.4% vs. 12.5%, P = 0.04). In a multivariate analysis, only retrograde LV access and advanced age were independent determinants of significant ABI. CONCLUSION: Significant ABI after ablation of VT in patients with SHD can be detected in one-fifth of subjects. Retrograde access to LV is associated with a two-fold higher probability of significant ABI.

In-hospital and 12-month follow-up outcome from the ESC-EORP EHRA Atrial Fibrillation Ablation Long-Term registry: sex differences.

AIM: The purpose of this study was to compare sex differences of atrial fibrillation (AF) catheter ablation (CA) and to analyse the opportunities for improved outcomes. METHODS AND RESULTS: All data were collected from the Atrial Fibrillation Ablation Long-Term registry, a prospective, multinational study conducted by the ESC-EORP European Heart Rhythm Association (EHRA) under the EURObservational Research Programme (ESC-EORP). A total of 104 centres in 27 European countries participated. Of 3593 included patients, 1146 (31.9%) were female. Female patients were older (61.0 vs. 56.4 years; P < 0.001), had more comorbidities (hypertension, diabetes, and obesity), more episodes of arrhythmias per month (6.9 vs. 6.2; P < 0.001), and a higher average EHRA score (2.6 vs. 2.4; P < 0.001). The duration of the procedure was shorter in females (160.1 min vs. 167.9 min; P < 0.001), irrespective of additional ablation lesions added to pulmonary vein isolation. Overall cardiovascular complications were more frequent in women than in men (5.7% vs. 3.4%; P < 0.001). Furthermore, cardiac perforations (3.8% vs. 1.3%; P = 0.011) and neurological complications (2.2% vs. 0.3%; P = 0.004) were found in females in less experienced centres than in experienced ones. On a final note, at 12 months, AF recurrence rate was similar in females and males (34.4% vs. 34.2%; P = 0.897), but more females were still on antiarrhythmic drugs (50.6% vs. 44.1%; P < 0.001) when compared with men. CONCLUSION: Females underwent CA procedures for AF less frequently than males throughout Europe, despite more recurrent symptoms. With the same success rate, severe acute complications remained considerable in females, especially in less experienced centres.

Ultrasound-guided versus conventional femoral venipuncture for catheter ablation of atrial fibrillation: a multicentre randomized efficacy and safety trial (ULTRA-FAST trial).

Aims: Complications of catheter ablation for atrial fibrillation (AF) are frequently related to vascular access. We hypothesized that ultrasound-guided (USG) venipuncture may facilitate the procedure and reduce complication rates. Methods and results: We conducted a multicentre, randomized trial in patients undergoing catheter ablation for AF on uninterrupted anticoagulation therapy. The study enrolled consecutive 320 patients (age: 63 ± 8 years; male: 62%) and were randomized to USG or conventional venipuncture in 1:1 fashion. It was prematurely terminated due to substantially lower-than-expected complication rates, which doubled the population size needed to maintain statistical power. While the complication rates did not differ between two study arms (0.6% vs. 1.9%, P = 0.62), intra-procedural outcome measures were in favour of the USG approach (puncture time, 288 vs. 369 s, P < 0.001; first pass success, 74% vs. 20%, P < 0.001; extra puncture attempts 0.5 vs. 2.1, P < 0.001; inadvertent arterial puncture 0.07 vs. 0.25, P < 0.001; unsuccessful cannulation 0.6% vs. 14%, P < 0.001). Though these measures varied between trainees (49% of procedures) and expert operators, between-arm differences (except for unsuccessful cannulation) were comparably significant in favour of USG approach for both subgroups. Conclusions: Ultrasound-guided puncture of femoral veins was associated with preferable intra-procedural outcomes, though the major complication rates were not reduced. Both trainees and expert operators benefited from the USG strategy. (www.clinicaltrials.gov ID: NCT02834221).

The tip of the muscle is a dominant location of ventricular ectopy originating from papillary muscles in the left ventricle.

INTRODUCTION: Frequent ventricular premature complexes (VPCs) may cause symptoms and/or lead to deterioration of LV systolic function. Although frequent VPCs may be abolished by catheter ablation, it may be challenging in case of their origin from the LV papillary muscles (PMs). Our collaborative study aimed to analyze in detail the site of origin and the outcome of ablation. METHODS: Consecutive 34 patients (males: 68%; aged 62 ± 12 years; LV ejection fraction: 50 ± 9%) undergoing catheter ablation of VPCs originating from PMs were included. All procedures were guided by intracardiac echocardiography. RESULTS: The size and shape of PMs were highly variable. The length of anterolateral and posteromedial PM was 23 ± 4 mm and 28 ± 7 mm, respectively. In about one-third of patients, the PM was formed by two distinctly separate heads. The ectopic foci were located on anterolateral, posteromedial or both PM in 35%, 56% and 9% of cases, respectively. Their location was found within the distal, mid, or proximal (basal) third of PM in the 67%, 19%, and 14%, respectively. A total of 86% of PM foci were acutely abolished and long-term success was achieved in 65% of patients. Absence of VPCs of other morphologies and a high burden of ectopic activity before ablation were associated with favorable clinical outcome. CONCLUSION: VPCs originate predominantly from the distal portion of the PM. This knowledge may facilitate the mapping in patients with infrequent ectopic beats. Intracardiac echocardiography is of crucial importance for navigation of the ablation catheter and for assessment of its stability at PM target sites.

Catheter ablation of atrial fibrillation in elderly population.

BACKGROUND: Although elderly patients have been included in published series of catheter ablation for atrial fibrillation (AF), clinical benefit and safety remain still less defined in this population. A retrospective analysis of the results of catheter ablation for AF in a large volume center focused on comparison of elderly patients with the rest of the patient cohort was conducted in this study. METHODS: Consecutive patients who underwent catheter ablation for AF between January 2001 and December 2016 were analysed. A total population of 3197 patients was dichotomized by the age of 70 years (394 elderly vs. 2803 younger subjects). Patients were followed in terms of arrhythmia status and survival for a median period of 18 vs. 21 and 35 vs. 57 months, respectively. RESULTS: Elderly patients were more frequently females (49% vs. 29%, P < 0.0001), had a history of hypertension (79% vs. 57%, P < 0.0001), diabetes (16% vs. 11%, P < 0.01), stroke (9% vs. 6%, P < 0.01), coronary/peripheral artery disease (14% vs. 8%, P < 0.0001), and CHA2DS2-VASc score (3.1 ± 1.3 vs. 1.5 ± 1.2 s, P < 0.0001). Major complications were more frequent in elderly (5.3% vs. 3.2%, P = 0.03); however, this difference was driven by vascular complications (3.6% vs. 1.9%, P = 0.04). There were comparable rates of cerebrovascular (0.3 vs. 0.3%) or nonvascular complications (1.8 vs. 1.2%). Good arrhythmia control was inferior in elderly patients as compared with the rest of the cohort, both without and with antiarrhythmic drugs: 44.2% vs. 58.2% (P < 0.0001) and 78.2 vs. 83.2% (P < 0.01), respectively. Poor arrhythmia control was associated with relative risk of all-cause mortality of 2.7 (95% CI: 1.1-6.4) in elderly patients and 1.4 (95% CI: 0.9-2.0) in younger subjects. CONCLUSIONS: Catheter ablation for AF in elderly patients is safe although somewhat less effective. Good arrhythmia control is associated with better survival, especially in elderly patients.

Outcomes of ventricular tachycardia ablation in patients with structural heart disease: The impact of electrical storm.

AIMS: To investigate predictors of long-term outcomes after catheter ablation (CA) for ventricular tachycardia (VT) and the impact of electrical storm (ES) prior to index ablation procedures. METHODS: We studied consecutive patients with structural heart disease and VT (n = 328; age: 63±12 years; 88% males; 72% ischaemic cardiomyopathy; LVEF: 32±12%) who had undergone CA. According to presenting arrhythmia at baseline, they were divided into ES (n = 93, 28%) and non-ES groups. Clinical predictors of all-cause mortality were investigated and a clinically useful risk score (SCORE) was constructed. RESULTS: During a median follow-up of 927 days (IQR: 564-1626), 67% vs. 60% of patients (p = 0.05) experienced VT recurrence in the ES vs. the non-ES group, respectively; and 41% vs. 32% patients died (p = 0.02), respectively. Five factors were independently associated with mortality: age >70 years (hazard ratio (HR): 1.6, 95% confidence interval (CI): 1.1-2.4, p = 0.01), NYHA class ≥3 (HR: 1.9, 95% CI: 1.2-2.9, p = 0.005), a serum creatinine level >1.3 mg/dL (HR: 1.6, 95% CI: 1.1-2.3, p = 0.02), LVEF ≤25% (HR: 2.4, 95% CI: 1.6-3.5, p = 0.00004), and amiodarone therapy (HR: 1.5, 95% CI: 1.0-2.2, p = 0.03). A risk SCORE ranging from 0-4 (1 point for either high-risk age, NYHA, creatinine, or LVEF) correlated with mortality. ES during index ablation independently predicted mortality only in patients with a SCORE ≤1. CONCLUSIONS: Advanced LV dysfunction, older age, higher NYHA class, renal dysfunction, and amiodarone therapy, but not ES, were predictors of poor outcomes after CA for VT in the total population. However, ES did predict mortality in a low-risk sub-group of patients.

Resting and Exercise-Induced Left Atrial Hypertension in Patients With Atrial Fibrillation: The Causes and Implications for Catheter Ablation.

OBJECTIVES: The aim of this paper was to investigate the prevalence of resting and exercise-induced left atrial hypertension (LAH) in patients with nonvalvular atrial fibrillation (AF), association of the LAH with other cardiac abnormalities, and its implications for AF catheter ablation. BACKGROUND: The clinical role of LAH in patients with established AF is largely unknown. METHODS: Patients scheduled for catheter ablation of AF (n = 240; age 60 ± 10 years; 67% men, 62% paroxysmal AF) underwent detailed echocardiography, assessment of quality of life (QoL), left atrial (LA) voltage mapping, and measurement of the LA pressure at rest and during isometric handgrip exercise. After ablation they were followed for AF recurrence for 16 ± 6 months. RESULTS: Resting and exercise-induced LAH (mean LA pressure >15 mm Hg) occurred in 15% and 34% of the patients, respectively. Both the patients with resting and exercise-induced LAH had typical features of latent heart failure with preserved ejection fraction associated with advanced LA structural and functional remodeling. AF recurred after ablation in 45% of the patients. LAH was an independent risk factor for arrhythmia recurrence (hazard ratio: 1.7, 95% confidence interval: 1.2 to 2.2). The patients with LAH had worse baseline QoL, but they benefited significantly more from a successful ablation than the patients without LAH. CONCLUSIONS: Presence of either resting or exercise-induced LAH identified AF patients with a distinct clinical profile, extensive LA substrate, and different clinical response to catheter ablation. Stratification of AF patients based on the LA exercise hemodynamics could help in the future to tailor the ablation strategy.

Differential effect of ganglionic plexi ablation in a patient with neurally mediated syncope and intermittent atrioventricular block.

AIMS: In patients with severe neurally mediated syncope (NMS), radiofrequency catheter ablation (RFA) of ganglionic plexi (GP) has been proposed as a new therapeutic approach. Cardio-inhibitory response during NMS is usually related to the sinoatrial (SA) and less frequently to atrioventricular (AV) node. Differential effect of GP ablation on SA and AV node is poorly understood. METHODS AND RESULTS: We report a case of a 35-year-old female with frequent symptomatic episodes of advanced AV block treated by anatomically guided RFA at empirical sites of GPs. After RFA at the septal portion of the right atrium-superior vena cava junction, heart rate accelerated from 62 to 91 beats/min and PR interval prolonged from 213 to 344 ms. Sustained first-degree AV block allowed to observe directly the effects of subsequent RFA on the AV nodal properties. Subsequent RFA at right- and left-sided aspects of the inter-atrial septum had no further effect on heart rate and PR interval. Ablation at the inferior left GP was critical for restoration of normal AV conduction (final PR interval of 187 ms). No bradycardia episodes were observed by implantable loop recorder during the follow-up of 10 months and the patient was symptomatically improved. CONCLUSION: This is the first clinical case showing the differential effect of GP ablation on SA and AV nodal function, and critical importance of targeting the GP at the postero-inferior left atrium. The successful procedure corroborates clinical utility of ablation treatment instead of pacemaker implantation in selected patients with cardio-inhibitory NMS.

Catheter Ablation of Ventricular Tachycardia in the Presence of an Old Endocavitary Thrombus Guided by Intracardiac Echocardiography.

BACKGROUND: Catheter ablation of ventricular tachycardia (VT) in patients with structural heart disease (SHD) is effective in prevention of arrhythmia recurrences. However, endocardial ablation may be challenging in the presence of organized left ventricular (LV) endocavitary thrombus. Our goal was to analyze the results of VT ablation in patients with identified old thrombus. METHODS AND RESULTS: We reviewed clinical and procedural data of 344 consecutive patients who underwent VT ablation for SHD. Old endocavitary thrombus was identified in four patients by preprocedural transthoracic echocardiography (TTE) and in four more patients by intracardiac echocardiography (ICE). All together, the case series of eight patients with detectable thrombus is reported. All patients (one woman, age: 67 ± 7 years) had postinfarction aneurysm (20 ± 8 years after the index myocardial infarction) and the thrombus was well organized without mobile structures. Arrhythmogenic substrate could not be obviously targeted beneath the base of thrombus; however, catheter ablation was successfully performed in the close vicinity. A total of 2.4 ± 1.2 procedures were necessary to abolish VT recurrences. Epicardial ablation was performed in three of eight (38%) patients as a second elective procedure. No procedural or periprocedural complications were observed. During the follow-up of 14 ± 15 months, two patients (25%) had sporadic VT recurrences. CONCLUSIONS: ICE seems to be more sensitive for the detection of LV thrombi compared to TTE and is helpful in real-time navigation of mapping/ablation catheter. Besides potential thromboembolic risk, large thrombus may prevent accessibility to the "critical" portion of arrhythmia circuit and epicardial ablation is required in selected cases.

Bipolar radiofrequency catheter ablation for refractory perimitral flutter: a case report.

BACKGROUND: Mitral isthmus is often targeted as a part of stepwise approach during radiofrequency ablation for persistent atrial ablation. Acute success rate in achieving the mitral isthmus block is only modest, late reconduction rate is relatively high and, consequently, incomplete lesion may be proarrhythmic. We describe the first-in-man experience with successful MI ablation by bipolar RF energy delivery. CASE PRESENTATION: A 64-year-old caucasian man after two previous ablation procedures for drug resistant atrial fibrillation in recent four years, which included pulmonary vein isolation and linear left atrial lesions, was referred for the treatment of recurrent perimitral flutter. Despite the third attempt to create bidirectional block at the mitral isthmus region, we were not even able to stop the arrhythmia by aggressive unipolar radiofrequency ablation both from the left atrium and coronary sinus, because of deeply embedded slow conducting channel probably around the vein of Marshall. Arrhythmia was finally terminated and the block was achieved by bipolar radiofrequency ablation between two irrigated-tip catheters positioned at the left atrial endocardium and contralaterally inside the coronary sinus. CONCLUSION: Bipolar radiofrequency energy delivery can be an option for ablation of perimitral flutter resistant to standard unipolar radiofrequency ablation. This may improve clinical outcome of patients undergoing non-pharmacological treatment for persistent atrial fibrillation. The safety and efficacy of this technique has to be confirmed in future studies.

Catheter Ablation of Ventricular Tachycardia as the First-Line Therapy in Patients With Coronary Artery Disease and Preserved Left Ventricular Systolic Function: Long-Term Results.

INTRODUCTION: Patients with coronary artery disease (CAD), relatively preserved left ventricular ejection fraction (LVEF), and hemodynamically tolerated ventricular tachycardia (VT) may benefit from catheter ablation as the first-line treatment. Our aim was to analyze the long-term results of VT ablation in this population. METHODS AND RESULTS: Thirty-one patients (1 woman, mean age 67 ± 10 years) with CAD, tolerated VT, and LVEF ≥40% underwent catheter ablation as the first-line treatment of the arrhythmia. Catheter ablation was performed in order to abolish all inducible VTs. An ICD was implanted if sustained VT of any morphology remained inducible after the procedure. The mean LVEF was 48 ± 6% and the mean VT cycle length reached 348 ± 70 milliseconds in the study cohort. Clinical and all inducible VTs were abolished in 90% (28/31) and 58% (18/31) of the patients, respectively. An ICD was subsequently implanted in 42% of cases. Over a mean follow-up of 3.8 ± 2.9 years, 42% (13/31) patients died. Survival of the patients with or without the ICD was not significantly different (P = 0.47). VT recurrence was observed in 11% (2/18) of patients who had complete elimination of all inducible VTs. No sudden death occurred in patients without the ICD. CONCLUSIONS: Catheter ablation of VT as the first-line treatment in patients with CAD and relatively preserved LVEF is a viable strategy. It may prevent implantation of the ICD in a considerable proportion of patients. Abolition of all inducible VTs confers low VT recurrence rate over a long-term follow-up.

EFFICAS II: optimization of catheter contact force improves outcome of pulmonary vein isolation for paroxysmal atrial fibrillation.

AIMS: A challenge of pulmonary vein isolation (PVI) in catheter ablation for paroxysmal atrial fibrillation (PAF) is electrical reconnection of the PV. EFFICAS I showed correlation between contact force (CF) parameters and PV durable isolation but no prospective evaluation was made. EFFICAS II was a multicentre study to prospectively assess the impact of CF guidance for an effective reduction of PVI gaps. METHODS AND RESULTS: Pulmonary vein isolation using a radiofrequency (RF) ablation catheter with an integrated force sensor (TactiCath™) was performed in patients with PAF. Operators were provided EFFICAS I-based CF guidelines [target 20 g, range 10-30 g, minimum 400 g s force-time integral (FTI)]. Conduction gaps were assessed by remapping of PVs after 3 months, and gap rate was compared with EFFICAS I outcome. At follow up, 24 patients had 85% of PVs remaining isolated, compared with 72% in EFFICAS I (P = 0.037) in which CF guidelines were not used. The remaining 15% of gaps correlated to the number of catheter moves at creating the PVI line, quantified as Continuity Index. For PV lines with contiguous lesions and low catheter moves, durable isolation was 81% in EFFICAS I and 98% in EFFICAS II (P = 0.005). At index procedure, the number of lesions was reduced by 15% in EFFICAS II vs. EFFICAS I. CONCLUSION: The use of CF with the above guidelines and contiguous deployment of RF lesions in EFFICAS II study resulted in more durable PVI in catheter ablation of PAF.

Complications of catheter ablation of ventricular tachycardia: a single-center experience.

BACKGROUND: Catheter ablation has become an established treatment modality for a broad spectrum of ventricular tachycardias (VTs). We analyzed incidence and predictors of major complications of VT ablation procedures in a high-volume expert center. METHODS AND RESULTS: We evaluated 548 consecutive patients who underwent 722 ablation procedures, 473 (65.5%) for structural heart disease VT in the period 2006 to 2012. There were 45 (6.2%) major complications observed in 44 patients. Access site vascular complications were the most frequent (3.6%). Three patients (0.4%) had cardiac tamponade/hemopericardium, and 5 patients (0.7%) had a thromboembolic event. No procedural deaths occurred. Procedures for structural heart disease VT versus idiopathic VT had a significantly higher complication rate (8.0% versus 2.8%; P=0.006). Similarly, patients with electrical storm (10.1% versus 5.3%; P=0.04) and nonelective procedures (8.4% versus 3.5%; P=0.007) were at higher risk of complications. On multivariate analysis, age >70 years (P=0.01), serum creatinine >115 µmol/L (P=0.0003), and individual operator (P=0.0001) were the only independent predictors of complications. Overall 30-day mortality in the structural heart disease VT group reached 5.0% (patients) and 3.6% (procedures). Death was associated with early recurrence of VT/ventricular fibrillation (P=0.003) and ablation for electrical storm (P=0.02). CONCLUSIONS: Complication rates for VT ablation are significantly lower in idiopathic VT or in elective procedures. Independent predictors of complications include age, renal insufficiency, and individual operator. Postprocedural mortality is predicted by early recurrence of VT/ventricular fibrillation and ablation for electrical storm.

Locations of high contact force during left atrial mapping in atrial fibrillation patients: electrogram amplitude and impedance are poor predictors of electrode-tissue contact force for ablation of atrial fibrillation.

BACKGROUND: During radiofrequency ablation, high electrode-tissue contact force (CF) is associated with increased risk of steam pop and perforation. The purpose of this study, in patients undergoing ablation of paroxysmal atrial fibrillation, was to: (1) identify factors producing high CF during left atrial (LA) and pulmonary vein mapping; (2) determine the ability of atrial potential amplitude and impedance to predict CF; and (3) explore the feasibility of controlling radiofrequency power based on CF. METHODS AND RESULTS: A high-density map of LA/pulmonary veins (median 328 sites) was obtained in 18 patients undergoing atrial fibrillation ablation using a 7.5-Fr irrigated mapping/ablation catheter to measure CF. Average CF was displayed on the 3D map. For 5682 mapped sites, CF ranged 1-144 g (median 8.2 g). High CF (≥35 g) was observed at only 118/5682 (2%) sites, clustering in 6 LA regions. The most common high CF site (48/113 sites in 17/18 patients) was located at the anterior/rightward LA roof, directly beneath the ascending aorta (confirmed by merging the CT image and map). Poor relationship between CF and either unipolar amplitude, bipolar amplitude, or impedance was observed. During ablation, radiofrequency power was modulated based on CF. All pulmonary veins were isolated without steam pop, impedance rise, or pericardial effusion. CONCLUSIONS: High CF often occurs at anterior/rightward roof, where the ascending aorta provides resistance to the LA. Atrial potential amplitude and impedance are poor predictors of CF. Controlling radiofrequency power based on CF seems to prevent steam pop and impedance rise without loss of lesion effectiveness.

Complications of catheter ablation for atrial fibrillation in a high-volume centre with the use of intracardiac echocardiography.

AIMS: Catheter ablation (CA) for atrial fibrillation (AF) is a complex procedure that is associated with higher risk of complications. This study aimed at exploring the complication rate and corresponding risk factors in a high-volume centre with routine use of intracardiac echocardiography (ICE). METHODS AND RESULTS: In total 1192 consecutive AF ablation procedures (100% ICE-guided; 96.4% 3D-navigated; point-by-point radiofrequency ablation with open-irrigated tip catheter; 22.4% robotic navigation; 25.4% repeated ablation) were performed in 959 patients (aged 58 ± 9 years; 70.8% males; 35.9% persistent AF) between March 2006 and December 2010. Ablation endpoint in paroxysmal AF was complete electrical pulmonary vein isolation (PVI). Complex ablation was defined as PVI plus stepwise strategy for left atrial substrate ablation (43.5%) in persistent AF. Forty major complications (3.3%) during the procedure or within the 3 month follow-up were observed. No death or atrioesophageal fistula occurred. Three patients (0.25%) had cardiac tamponade/hemopericardium and five patients (0.42%) had cerebrovascular embolic event. Vascular injury was the most frequent (2.3%) complication. Low body weight was the only significant risk factor with 0.8% increase of complication rate per 10 kg of body weight decrease (P = 0.013). A trend for increase in complication rate was also observed for advanced age, female gender, and complex procedure. CONCLUSION: Atrial fibrillation ablation procedures guided by ICE in a high-volume centre are associated with low rate of serious complications. The composite risk score consisting of body weight, age, gender, and complexity of procedure predicted complications.

A pilot study of systolic dyssynchrony index by real time three-dimensional echocardiography and Doppler tissue imaging parameters predicting the hemodynamic response to biventricular pacing in the early postoperative period after cardiac surgery.

OBJECTIVE: To evaluate systolic dyssynchrony index (SDI) measured by real time three-dimensional echocardiography (RT3DE) and Doppler tissue imaging (DTI) dyssynchrony parameters in predicting the hemodynamic response to biventricular (BIV) pacing in the early postoperative period after cardiac surgery. To compare right ventricular (RV) and BIV pacing using invasively measured hemodynamic values. METHODS: A prospective randomized clinical study enrolling 11 patients with ischemic heart disease, concomitant valvular heart disease, and left ventricular ejection fraction (LVEF) ≤ 35% comparing preoperative SDI by RT3DE and DTI LV dyssynchrony parameters to hemodynamic values obtained during RV or BIV sequential (DDD) epicardial pacing in the first 72 hours after cardiac surgery. RESULTS: BIV pacing produced a statistically significant higher cardiac output (CO) (6.27 ± 1.55 L/min) and cardiac index (CI) (3.44 ± 0.93 L/min per m(2) ) than RV pacing (CO 5.44 ± 0.97 L/min, CI 3.03 ± 0.83 L/min per m(2) , P < 0.05). We found a statistically moderate correlation between preoperative SDI by RT3DE and CO (r = 0.596, P < 0.05) and a nonsignificant correlation to CI (r = 0.535, P < 0.10) during BIV pacing. No correlation was observed between DTI dyssynchrony parameters and measured hemodynamic values. BIV pacing reduced the ICU stay and inotropic support requirements of patients after heart surgery. CONCLUSIONS: SDI measured preoperatively using RT3DE can predict CO during BIV pacing in the early postoperative period after cardiac surgery. BIV pacing is more hemodynamically effective than RV pacing in patients with LV dysfunction after coronary artery bypass grafting with or without a valve procedure.