Regional variations in patient selection and procedural characteristics for cryoballoon ablation of atrial fibrillation in the cryo global registry.

BACKGROUND: Cryoballoon ablation is a well-established anatomical approach for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Although widely adopted, regional variations in standards of care have not been well characterized. METHODS: Patients with AF were enrolled in the Cryo Global Registry (NCT02752737) from May 2016 to Sept 2021 at 128 sites in 37 countries and treated with cryoballoon ablation according to local clinical practice. Baseline patient and procedural characteristics were summarized for 8 regions (Central Asia & Russia, East Asia, Europe, Middle East, North America, South Africa, South America, and Southeast Asia). Serious procedure-related adverse events (SAEs) were evaluated in a subset of patients with ≥ 7 days of follow-up. RESULTS: A total of 3,680 patients undergoing initial PVI for AF were included. Cryoballoon ablation was commonly performed in patients with paroxysmal AF. Mean age ranged from 47 ± 12 years in the Middle East to 64 ± 11 years in East Asia. Mean procedure time was ≤ 95 min in all regions. Average freeze duration ranged from 153 ± 41 s in Southeast Asia to 230 ± 29 s in Central Asia & Russia. Acute procedural success was ≥ 94.7% in all geographies. In 3,126 subjects with ≥ 7 days of follow-up, 122 procedure-related SAEs were reported in 111 patients (3.6%) and remained low in all regions. One procedure-related death was reported during data collection. CONCLUSIONS: Despite regional variations in patient selection and procedural characteristics, PVI using cryoballoon ablation was performed with high acute success and short procedural times around the world. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02752737.

Prevalence of Lyme Carditis in Patients with Atrioventricular Blocks.

Infections with Borrelia may cause cardiac conduction system abnormalities, including atrioventricular blocks (AVBs). Therefore, we aimed to identify patients in whom Lyme carditis (LC) could be considered as the initial diagnosis among consecutive subjects who were referred for implantation of a permanent pacemaker due to symptomatic AVBs. To date, such a systematic evaluation has not been reported yet. Validation of the Suspicious Index for Lyme Carditis (SILC) in our study population was considered as an additional goal. We investigated consecutive patients with AVB admitted to our department for a pacemaker implantation. Serological diagnostic tests against Borrelia burgdorferi sensu lato (Bbsl) were performed in those with no obvious cardiac causes of AVB. The final study population consisted of 130 patients (80 M, mean age 67.4 ± 17.6). Lyme carditis was assumed as the initial diagnosis in 16 patients (12%) based on ABV and IgM Bbsl seropositivity. The patients with LC were younger and more frequently manifested constitutional symptoms of infection and fluctuating AVB. The highest prognostic value for identification of LC patients was obtained for the modified SILC, which included the following parameters: (1) age lower than 75 years; (2) risky outdoor activity and living in the countryside; (3) tick bite; (4) constitutional symptoms of Lyme disease; (5) erythema migrans; (6) male sex and (7) fluctuating atrioventricular block. We concluded that diagnostics for LC should be routinely considered in patients with advanced AVB. Modified SILC may identify the patients at risk of LC.

Dutogliptin in Combination with Filgrastim in Early Recovery Post-Myocardial Infarction-The REC-DUT-002 Trial.

Patients with acute myocardial infarction are at high risk for developing heart failure due to scar development. Although regenerative approaches are evolving, consistent clinical benefits have not yet been reported. Treatment with dutogliptin, a second-generation DPP-4 inhibitor, in co-administration with filgrastim (G-CSF) has been shown to enhance endogenous repair mechanisms in experimental models. The REC-DUT-002 trial was a phase 2, multicenter, double-blind placebo-controlled trial which explored the safety, tolerability, and efficacy of dutogliptin and filgrastim in patients with ST-elevation Myocardial Infarction (STEMI). Patients (n = 47, 56.1 ± 10.7 years, 29% female) with STEMI, reduced left ventricular ejection fraction (EF ≤ 45%) and successful revascularization following primary PCI were randomized to receive either study treatment or matching placebo. Cardiac magnetic resonance imaging (cMRI) was performed within 72 h post-PCI and repeated after 3 months. The study was closed out early due to the SARS-CoV-2 pandemic. There was no statistically significant difference between the groups with respect to serious adverse events (SAE). Predefined mean changes within cMRI-derived functional and structural parameters from baseline to 90 days did not differ between placebo and treatment (left ventricular end-diastolic volume: +13.7 mL vs. +15.7 mL; LV-EF: +5.7% vs. +5.9%). Improvement in cardiac tissue health over time was noted in both groups: full-width at half-maximum late gadolinium enhancement (FWHM LGE) mass (placebo: -12.7 g, treatment: -19.9 g; p = 0.23). Concomitant treatment was well tolerated, and no safety issues were detected. Based on the results, the FDA and EMA have already approved an adequately powered large outcome trial.

Systemic Brucellosis with Arrhythmogenic Cardiac Inflammatory Pseudotumor.

BACKGROUND Cardiac inflammatory pseudotumors are rarely observed. Their etiology might include immunologic abnormalities, fibrogenetic disorders, specific reactions to infections or abnormalities related to trauma, necrosis, or neoplasm. Life-threatening ventricular tachycardia and cases of sudden death related to cardiac tumors have been reported. The present report describes and discusses diagnostic and therapeutic solutions for the treatment of nonsarcoid multiorgan pseudotumors with cardiac involvement. CASE REPORT A 38-year-old woman presented to the clinic with symptomatic ventricular tachycardia. As coronary artery disease, cardiomyopathy, and channelopathy were ruled out, and electrocardiograms were not typical of idiopathic arrhythmia, the patient underwent detailed diagnostics which included targeted endomyocardial biopsy, which revealed a cardiac inflammatory pseudotumor. Laborious testing (and eventually, antibiotic therapy) led to ex juvantibus diagnosis of multiorgan disseminated brucellosis with cardiac involvement. Treatment with ceftriaxone, doxycycline, and rifampicin resulted in a complete resolution of all lesions after 3 months, and sustained recovery was observed during a 5-year follow-up. As the risk of ventricular tachycardia could not be reliably predicted, the patient had a subcutaneous implantable cardioverter-defibrillator implanted. CONCLUSIONS A vast diagnostic armamentarium of modern medicine allowed us to diagnose an unsuspected and rare cardiac inflammatory pseudotumor. In the case of travelers, the possibility of regionally specific illnesses, especially infections, must be taken into consideration as possible causes of arrhythmias. Cardiac magnetic resonance imaging may be useful in patients with 'idiopathic ventricular tachycardias' to detect non-apparent myocardial lesions which may result from the underlying cause of the arrhythmia.

A Randomized, double-blind, dose ranging clinical trial of intravenous FDY-5301 in acute STEMI patients undergoing primary PCI.

BACKGROUND: Ischemia-reperfusion injury remains a major clinical problem in patients with ST-elevation myocardial infarction (STEMI), leading to myocardial damage despite early reperfusion by primary percutaneous coronary intervention (PPCI). There are no effective therapies to limit ischemia-reperfusion injury, which is caused by multiple pathways activated by rapid tissue reoxygenation and the generation of reactive oxygen species (ROS). FDY-5301 contains sodium iodide, a ubiquitous inorganic halide and elemental reducing agent that can act as a catalytic anti-peroxidant. We tested the feasibility, safety and potential utility of FDY-5301 as a treatment to limit ischemia-reperfusion injury, in patients with first-time STEMI undergoing emergency PPCI. METHODS: STEMI patients (n = 120, median 62 years) presenting within 12 h of chest pain onset were randomized at 20 PPCI centers, in a double blind Phase 2 clinical trial, to receive FDY-5301 (0.5, 1.0 or 2.0 mg/kg) or placebo prior to reperfusion, to evaluate the feasibility endpoints. Participants underwent continuous ECG monitoring for 14 days after PPCI to address pre-specified cardiac arrhythmia safety end points and cardiac magnetic resonance imaging (MRI) at 72 h and at 3 months to assess exploratory efficacy end points. RESULTS: Intravenous FDY-5301 was delivered before re-opening of the infarct-related artery in 97% participants and increased plasma iodide levels ~1000-fold within 2 min. There was no significant increase in the primary safety end point of incidence of cardiac arrhythmias of concern. MRI at 3 months revealed median final infarct sizes in placebo vs. 2.0 mg/kg FDY-5301-treated patients of 14.9% vs. 8.5%, and LV ejection fractions of 53.9% vs. 63.2%, respectively, although the study was not powered to detect statistical significance. In patients receiving FDY-5301, there was a significant reduction in the levels of MPO, MMP2 and NTproBNP after PPCI, but no reduction with placebo. CONCLUSIONS: Intravenous FDY-5301, delivered immediately prior to PPCI in acute STEMI, is feasible, safe, and shows potential efficacy. A larger trial is justified to test the effects of FDY-5301 on acute ischemia-reperfusion injury and clinical outcomes. CLINICAL TRIAL REGISTRATION: CT.govNCT03470441; EudraCT 2017-000047-41.

Impedance fluctuation and steam pop occurrence during radiofrequency current ablation: An experimental in vitro model.

BACKGROUND: The radiofrequency impedance measurement is one of the basic parameters monitored during ablation procedures. An abrupt rise in impedance is often observed corresponding to a steam pop. The exact correlation between the occurrence of steam pop and subsequent rise in impedance has not been experimentally described so far. OBJECTIVES: To evaluate the relationship between steam pop occurrence and impedance fluctuations observed during radiofrequency ablation (RFA). MATERIAL AND METHODS: Porcine heart tissue specimens were appropriately prepared and placed in an experimental setup connected to electrophysiological equipment with 3D anatomical mapping facilities. The RFA lesions were performed in standardized conditions with the use of contact force measurement-enabled open irrigation ablation catheter (ThermoCool SmartTouch™, 3.5 mm tip, F-J curvature; Biosense Webster, Irvine, USA) in the power-control mode. The RFA delivery was stopped when the steam pop occurred. Time taken for the steam pop to occur and to the subsequent abrupt impedance rise was recorded, along with the impedance fluctuations during an application. RESULTS: In total, 25 experimental radiofrequency (RF) current deliveries ended up with steam pops, which occurred after 30-60 s. The time recorded from the beginning of the application up to the steam pop was shorter if increased power was applied (35 W compared to 30 W: 41.5 ±9.9 s compared to 49.9 ±8.2 s; p = 0.046). During all RF applications, impedance significantly but gradually decreased from 122.9 ±7.9 Ω to 87.5 ±3.6 Ω (p < 0.001) with a mean drop rate of 0.8 ±0.2 Ω/s. During all experiments, the abrupt and significant impedance increase (8.2 ±2.0 Ω, p < 0.001) was observed always after steam pop occurrence (207.4 ±155.9 ms). CONCLUSIONS: During RF current delivery which ended up with steam pop, an abrupt impedance increase was always registered after the occurrence of this phenomenon. Therefore, the impedance rise observed during steam popping cannot be used for its prediction. The time to steam pop was shorter for applications with increased power but not with greater contact force.

The safety, efficacy, and cost-effectiveness of gentamycin-collagen sponge in multicomponent prevention strategy of cardiac implantable electronic device infections - a single-center experience.

BACKGROUND: Cardiac implantable electronic device(CIED)infections are associated with significant morbidity, mortality, and increased healthcare expenses. Apart from standard systemic antibiotic therapy, locally acting agents are under investigation as a potential approach for the prevention of this complication. AIMS: The study aimed to summarize our experience with a gentamycin-collagen sponge (GCS) in a multi-component prevention strategy of cardiac implantable electronic device infection. METHODS: We retrospectively analyzed medical records of 312 consecutive patients who underwent CIED-related surgery and had at least a 6-month follow-up. All the individuals had GCS applied during surgery. An incidence of CIEDs-related infection in our group was compared to the risk level calculated according to the commonly used scores. Analysis of cost-effectiveness was also performed. RESULTS: Incidence of CIED-related infection, defined as a primary endpoint, occurred relatively rarely (0.33%) as compared to the infection risk calculated according to commonly used scores Prevention of Arrythmia Device Infection Trial (PADIT) - 0.83%; CIED-AI - 0.90% or Mittal score - 1.00%; P<0.001 - for all). We did not record any complications related to GCS. We analyzed the cost-effectiveness of our GCS-based approach, which appeared to be financially beneficial (number needed to treat 149-200; difference of CIED infection treatment cost and GCSs price was 5093-26525 $). CONCLUSIONS: We conclude that: (1) the use of GCS to reduce CIEDs infections is feasible and safe; (2) our multicomponent prevention strategy involving the GCS application seems to significantly reduce the rate of CIED infection, and it is cost-effective.

Safety of cryoballoon ablation for the treatment of atrial fibrillation: First European results from the cryo AF Global Registry.

BACKGROUND: Cryoballoon ablation for the treatment of patients with atrial fibrillation (AF) has been utilized in Europe for >15 years. OBJECTIVES: Report patient and procedural characteristics that influence the safety of cryoablation for the treatment of AF. METHODS: Patients enrolled in the prospective, multicenter Cryo AF Global Registry were treated at 38 European centers. Freedom from a ≥30s episode of AF/atrial flutter (AFL)/atrial tachycardia (AT) at 12-months and serious complications were analyzed. Univariate and multivariable models identified baseline patient and procedural characteristics that predicted a procedure-related complication. RESULTS: Of the 1418 subjects who completed an index procedure, the cohort was 62 ± 11 years of age, 37.7% female, and 72.2% paroxysmal AF (PAF). The mean procedure, left atrial dwell, and fluoroscopy times were 81 ± 34, 54 ± 25, and 14 ± 13 min, respectively. Among the 766 patients with 12-month follow-up, freedom from a ≥30 s AF/AFL/AT recurrence was 83.3% (95% CI: 79.8%-86.3%) and 71.6% (95% CI: 64.6%-77.4%) in patients with PAF and persistent AF. The serious procedure- and device-related adverse event rates were 4.7% and 2.0%. No baseline patient characteristic independently predicted a procedure-related adverse event; however, prolonged procedure duration (OR = 1.01 [95% CI: 1.00-1.01]), use of general anesthesia (OR = 1.71 [95% CI: 1.01-2.92]), and delivery of a cavotricuspid isthmus line (OR = 3.04 [95% CI: 1.01-9.20]) were each independently associated with the occurrence of a serious procedural safety event (all p < .05). CONCLUSIONS: Cryoballoon ablation is safe and effective in real-world use across a broad cohort of patients with AF.

Percutaneous Occlusion of the Left Atrial Appendage with Thrombus Irresponsive to Antithrombotic Therapy.

We analyzed clinical experience with percutaneous closure of instances of left atrial appendage with thrombus (LAAT) irresponsive to antithrombotic therapy in patients treated in three high-volume cardiology centers. Clinical and procedural data regarding consecutive patients who underwent percutaneous left atrial appendage closure (PLAAC) due to LAAT were retrospectively analyzed. The study population consisted of 17 patients (11 men; 68 ± 14 years; CHA2DS2VASC 4.7 ± 1.9; HASBLED 3 (0-5)) with LAAT confirmed by transesophageal echocardiography, and included 5 patients with mechanical heart valves. Most of the patients (94.1%) received anticoagulation therapy before PLAAC. All LAATs were located in distal portions of the appendage and occupied less than 30% of its volume. Occluding-device implantation was successful in 17 patients; in one, a residual leak was disclosed. Appropriate positioning of occluders required more than 1 attempt in 6 individuals (35.3%); in 3 others (17.6%), the subjects' devices had contact with thrombi. No procedural complications were noted. Midterm follow-up (median: 10 months) revealed no procedure-related complications or clinically diagnosed thromboembolism. Transesophageal echocardiography (TEE) performed after six months revealed device-related thrombus in one patient. We concluded that LAAT irresponsive to antithrombotic therapy might be effectively treated with PLAAC, even in patients with mechanical-valve prostheses.

New Polish prototypes of 4- and 8-mm-tip nonirrigated radiofrequency ablation catheters: an in vitro study.

BACKGROUND: Effectiveness of lesion formation during radiofrequency (RF) catheter ablation can be assessed using in vitro or in vivo animal models. AIMS: In this in vitro study, we aimed to compare the prototypes of the first Polish RF ablation catheters with common commercially available catheters from other manufacturers. METHODS: Samples of the porcine left ventricle were subject to temperature-controlled ablation (50 W / 50 oC / 60 s), using 4- and 8-mm -tip nonirrigated ablation catheters (commercial ones as well as new prototypes). The parameters of RF delivery were collected during energy applications. Subsequently, lesion dimensions were measured and compared between catheters. RESULTS: Initial impedance and impedance drop during energy delivery differed significantly between catheters (both those with 4-mm and 8-mm tip electrodes). The maximum temperature was similar for 4-mm -tip catheters (P = 0.26), while it differed for 8-mm -tip ones (P <0.001). No significant differences between catheters were noted for lesion volume. The 8-mm -tip prototypes created lesions of greater depth (mean [SD], 5.8 [0.4] mm vs 4.7 [0.4] mm; P <0.001) and volume (mean [interquartile range], 239.4 [217.9-255.5] mm3 vs 173.7 [156.1-186.4] mm3; P <0.001) than those with a 4-mm tip electrode. CONCLUSIONS: Our study showed that RF ablation catheters with the same length of the tip electrode created lesions of similar volume, irrespective of the manufacturer and despite showing distinct physical parameters during energy applications. The Polish catheter prototypes showed similar performance as commercially available devices. Finally, 8-mm -tip prototypes produced lesions of greater depth and volume than those with a 4-mm tip electrode.

Multicentre early experience with totally subcutaneous cardioverter-defibrillators in Poland.

INTRODUCTION: Implantable cardioverter-defibrillators (ICD) have a strong position in the prevention of sudden death. Nowadays, the most commonly used high-energy cardiac devices are transvenous ICDs. A new technology of totally subcutaneous ICDs (S-ICD) was invented and recently introduced into clinical practice in order to reduce lead-related complications of conventional ICDs. The aim of this paper is to present early experience with this new technology implemented in a few centres in Poland. MATERIAL AND METHODS: Medical records of patients who had S-ICD-related interventions in Poland were retrospectively analysed. RESULTS: During the first year of S-ICD introduction into the Polish health system 18 patients underwent surgery connected with S-ICDs. Majority of them (17 patients) were implanted de novo. In one patient surgical revision of a device implanted abroad was performed. Most of patients (78%) had S-ICDs implanted for secondary prevention. Inability of transvenous system implantation due to venous access obstruction or high risk of infection related with transvenous leads accounted for 83% of indications for S-ICD. Only in three patients were S-ICDs implanted due to young age and active mode of life. The implantations of S-ICDs were performed without important early or late complications. During follow-up one patient had episodes of ventricular arrhythmia successfully terminated with high-energy shocks. One patient died due to progression of heart failure. CONCLUSIONS: S-ICD implantation procedure has been successfully and safely introduced in Polish clinical routine. Nevertheless, despite clear indications in recent ESC guidelines, this therapy is not directly reimbursed in Poland and needs individual application for refund.

Effect of Renal Denervation and Catheter Ablation vs Catheter Ablation Alone on Atrial Fibrillation Recurrence Among Patients With Paroxysmal Atrial Fibrillation and Hypertension: The ERADICATE-AF Randomized Clinical Trial.

Importance: Renal denervation can reduce cardiac sympathetic activity that may result in an antiarrhythmic effect on atrial fibrillation. Objective: To determine whether renal denervation when added to pulmonary vein isolation enhances long-term antiarrhythmic efficacy. Design, Setting, and Participants: The Evaluate Renal Denervation in Addition to Catheter Ablation to Eliminate Atrial Fibrillation (ERADICATE-AF) trial was an investigator-initiated, multicenter, single-blind, randomized clinical trial conducted at 5 referral centers for catheter ablation of atrial fibrillation in the Russian Federation, Poland, and Germany. A total of 302 patients with hypertension despite taking at least 1 antihypertensive medication, paroxysmal atrial fibrillation, and plans for ablation were enrolled from April 2013 to March 2018. Follow-up concluded in March 2019. Interventions: Patients were randomized to either pulmonary vein isolation alone (n = 148) or pulmonary vein isolation plus renal denervation (n = 154). Complete pulmonary vein isolation to v an end point of elimination of all pulmonary vein potentials; renal denervation using an irrigated-tip ablation catheter delivering radiofrequency energy to discrete sites in a spiral pattern from distal to proximal in both renal arteries. Main Outcomes and Measures: The primary end point was freedom from atrial fibrillation, atrial flutter, or atrial tachycardia at 12 months. Secondary end points included procedural complications within 30 days and blood pressure control at 6 and 12 months. Results: Of the 302 randomized patients (median age, 60 years [interquartile range, 55-65 years]; 182 men [60.3%]), 283 (93.7%) completed the trial. All successfully underwent their assigned procedures. Freedom from atrial fibrillation, flutter, or tachycardia at 12 months was observed in 84 of 148 (56.5%) of those undergoing pulmonary vein isolation alone and in 111 of 154 (72.1%) of those undergoing pulmonary vein isolation plus renal denervation (hazard ratio, 0.57; 95% CI, 0.38 to 0.85; P = .006). Of 5 prespecified secondary end points, 4 are reported and 3 differed between groups. Mean systolic blood pressure from baseline to 12 months decreased from 151 mm Hg to 147 mm Hg in the isolation-only group and from 150 mm Hg to 135 mm Hg in the renal denervation group (between-group difference, -13 mm Hg; 95% CI, -15 to -11 mm Hg; P < .001). Procedural complications occurred in 7 patients (4.7%) in the isolation-only group and 7 (4.5%) of the renal denervation group. Conclusions and Relevance: Among patients with paroxysmal atrial fibrillation and hypertension, renal denervation added to catheter ablation, compared with catheter ablation alone, significantly increased the likelihood of freedom from atrial fibrillation at 12 months. The lack of a formal sham-control renal denervation procedure should be considered in interpreting the results of this trial. Trial Registration: ClinicalTrials.gov Identifier: NCT01873352.

Diagnosis and management of left atrial appendage thrombus in patients with atrial fibrillation undergoing cardioversion or percutaneous left atrial procedures: results of the European Heart Rhythm Association survey.

Practices regarding indications and timing for transoesophageal echocardiography (TOE) before cardioversion (CV) of atrial fibrillation (AF) or left atrial (LA) interventional procedures, and preferred imaging techniques and pharmacotherapy, in cases of thrombus resistant to chronic oral anticoagulation (OAC) treatment, are largely unknown. The European Heart Rhythm Association (EHRA) conducted a survey to capture contemporary clinical practice in those areas of AF care. A 22-item online questionnaire was developed and distributed among the EHRA electrophysiology research network centres. The survey contained questions regarding indications, type and timing of imaging before CV or LA procedures and management of LA appendage (LAA) thrombus with special emphasis on thrombus resistant to OAC. Of 54 responding centres 63% were university hospitals. Most commonly, TOE would be performed in cases of inadequate or unclear pre-procedural anticoagulation, even in AF lasting <48 h (52% and 50%, respectively), and 15% of centres would perform TOE before AF ablation in all patients. If thrombus was diagnosed despite chronic OAC, the prevalent strategy was to change current OAC to another with different mechanism of action; 51% of centres would wait 3-4 weeks after changing the OAC before using another imaging test, and 60% of centres reported two attempts to dissolve the thrombus. Our survey showed a significant utilization of TOE before CV or AF ablation in European centres, extending beyond AF guidelines-suggested indications. When thrombus was diagnosed despite chronic pre-procedural OAC, most centres would use another anticoagulant drug with different mode of action.

Baseline intrinsic heart rate and response to ivabradine treatment in patients with inappropriate sinus tachycardia.

BACKGROUND: Treatment with ivabradine became a new therapeutic alternative for patients with inappropriate sinus tachycardia (IST). The aim was to determine a relation between intrinsic heart rate (IHR) and response to ivabradine treatment. METHODS: Twenty-seven patients (mean age 37 ± 11; 23 women) with symptomatic IST despite medical treatment were recruited into the study. Resting ECG, 24-hr ECG monitoring (24hECG), exercise treadmill test, and symptoms evaluation were performed initially and after 60 days on ivabradine. IHR was acquired at baseline after pharmacological autonomic blockade. RESULTS: Nineteen patients (70%) were classified as abnormal IHR group (AIHR) while eight showed normal IHR (NIHR). No significant differences in ECG parameters were found between NIHR and AIHR subgroups, while baseline exercise capacity was higher in AIHR patients (10.9 vs. 9.5 METs, p < .05). Ivabradine treatment resulted in significant reduction in resting heart rate, average 24hECG heart rate, improvement in exercise capacity and reduction of symptoms in both subgroups. Nevertheless, favorable influence of ivabradine was significantly more exaggerated in AIHR subgroup (HR 116 vs. 90 bpm, av. HR 98 vs. 79 bpm, 10.9 vs. 13.6 METS, EHRA score 3.1 vs. 1.1, p < .001 for all) than in NIHR patients (HR 112 vs. 98 bpm, av. HR 97 vs. 88 bpm, 9.5 vs. 11.1 METs, EHRA score 3.1 vs. 1.9; p < .05 for all). CONCLUSIONS: Intrinsic heart rate may be useful in predicting response to ivabradine in patients with IST. More intense response to ivabradine in patients with AIHR may be attributed to different pathophysiological mechanisms underlying IST in AIHR and NIHR groups.

Severe atrial fibrosis as a cause of significant intraatrial conduction delay in a patient with scleromyositis.

Scleromyositis is an autoimmune disease and an overlap syndrome of scleroderma and poly/dermatomyositis. It is characterized by frequent cardiovascular involvement including heart failure, arrhythmias and conduction disturbances. We present a case of a 73-year old female patient who required an upgrade from a DDD pacemaker to cardiac resynchronization therapy due left ventricular dysfunction and permanent ventricular pacing. Electroanatomical mapping (CARTO 3D) revealed extensive right atrial fibrosis which resulted in significant delay in intraatrial conduction. Interval from atrial paced stimulus to A signal in His bundle was 364 ms, while AH and HV intervals were within normal range.

Straight and crosier­shaped catheter techniques for phrenic nerve stimulation during cryoballoon pulmonary vein isolation for the treatment of atrial fibrillation.

BACKGROUND: Cryoablation is an effective and safe method of pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF). However, monitoring of phrenic nerve function during cryoballoon PVI remains an important issue. AIMS: We aimed to compare 2 techniques of phrenic nerve stimulation (PNS) with the use of either a straight or a crosier­shaped decapolar deflectable catheter. METHODS: The study included 218 patients (mean [SD] age, 61.8 [10.9] years; 87 women) referred for cryoballoon PVI for AF. Patients were randomly assigned to PNS with either a straight or a crosier­shaped catheter. RESULTS: The groups did not differ in demographic characteristics or PVI effectiveness. The current threshold during PNS was lower in the group in which the crosier­shaped catheter was applied (mean [SD], 6.7 [4.9] mA vs 4.8 [3.7] mA; P <0.01). In this group, the procedure time was shorter (mean [SD], 72.6 [22.8] min vs 64.4 [14.8] min; P <0.01), fewer repositioning maneuvers were required (31.8% vs 19.4%; P <0.05), and atrial capture during PNS was observed more frequently (11.5% vs 29.6%; P <0.01). CONCLUSIONS: Straight and crosier­shaped catheter techniques are equally effective in monitoring for phrenic nerve palsy. The crosier­shaped catheter maintains its position better, thus leading to fewer dislocations and requiring fewer correction maneuvers, which might correlate with shorter procedure time. Moreover, this technique provides lower pacing thresholds. Both techniques may be safely used in patients with AF, and if stable phrenic nerve capture cannot be achieved, switching to another technique seems reasonable.