Radiofrequency catheter ablation of ventricular tachycardia using combined endocardial techniques in patients with structural heart disease improves procedural effectiveness and reduces arrhythmia episodes.

BACKGROUND: Evidence indicates that radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in patients with structural heart disease (SHD) is safe and effective. However, arrhythmia recurrence is still relatively high, and the optimal procedural strategy is unclear. In clinical practice, several combinations of mapping and ablation techniques are used to improve VT ablation efficacy. AIM: The study aimed to evaluate and provide evidence on the efficiency and safety of a systematized combination of VT ablation (mapping) techniques in patients with SHD. METHODS: From 2016 to 2019, 47 patients (54 procedures) with SHD (89% heart failure, 94% ischemic heart disease, 37% VT storm) who underwent RFCA of VT were retrospectively analyzed from a group of 58 consecutive patients. During RFCA of VT, different combinations of three techniques, activation mapping (AM), pace mapping (PM), and substrate-based mapping (SbM), were used. The procedures were performed using the CARTO® 3 (Biosense Webster Inc., Diamond Bar, CA, US) electro-anatomical mapping system. RESULTS: During a median (interquartile range [IQR]) follow-up of 25.5 months (11.75-52.25), VT-free survival after ablation was 68.5% (n = 37/54 procedures). Acute procedural success was achieved in 85% (n = 46/54 procedures). The number of induced VT morphologies, induction of non-clinical or non-sustained VT after ablation, and fewer VT mapping techniques used during the procedure were related to decreasing VT-free survival. CONCLUSIONS: VT ablation strategy based on systemic use of combined techniques is effective and safe in long-term follow-up of patients with SHD.

Prevalence of Arrhythmia in Adults after Fontan Operation.

Structural, hemodynamic, and morphological cardiac changes following Fontan operation (FO) can contribute to the development of arrhythmias and conduction disorders. Sinus node dysfunction, junction rhythms, tachyarrhythmias, and ventricular arrhythmias (VAs) are some of the commonly reported arrhythmias. Only a few studies have analyzed this condition in adults after FO. This study aimed to determine the type and prevalence of arrhythmias and conduction disorders among patients who underwent FO and were under the medical surveillance of the John Paul II Hospital in Krakow. Data for the study were obtained from 50 FO patients (mean age 24 ± 5.7 years; 28 men (56%)). The median follow-up time was 4 (2-9) years. Each patient received a physical examination, an echocardiographic assessment, and a 24 h electrocardiogram assessment. Bradyarrhythmia was diagnosed in 22 patients (44%), supraventricular tachyarrhythmias in 14 patients (28%), and VAs in 6 patients (12%). Six patients required pacemaker implantation, and three required radiofrequency catheter ablation (6%). Arrythmias is a widespread clinical problem in adults after FO. It can lead to serious haemodynamic impairment, and therefore requires early diagnosis and effective treatment with the use of modern approaches, including electrotherapy methods.

Contact Force-Sensing versus Standard Catheters in Non-Fluoroscopic Radiofrequency Catheter Ablation of Idiopathic Outflow Tract Ventricular Arrhythmias.

BACKGROUND: Adequate contact between the catheter tip and tissue is important for optimal lesion formation and, in some procedures, it has been associated with improved effectiveness and safety. We evaluated the potential benefits of contact force-sensing (CFS) catheters during non-fluoroscopic radiofrequency catheter ablation (NF-RFCA) of idiopathic ventricular arrhythmias (VAs) originating from outflow tracts (OTs). METHODS: A group of 102 patients who underwent NF-RFCA (CARTO, Biosense Webster Inc., Irvine, CA, USA) of VAs from OTs between 2014 to 2018 was retrospectively analyzed. RESULTS: We included 52 (50.9%) patients in whom NF-RFCA was performed using CFS catheters and 50 (49.1%) who were ablated using standard catheters. Arrhythmias were localized in the right and left OT in 70 (68.6%) and 32 (31.4%) patients, respectively. The RFCA acute success rate was 96.1% (n = 98) and long-term success during a minimum 12-month follow-up (mean 51.3 ± 21.6 months) was 85.3% (n = 87), with no difference between CFS and standard catheters. There was no difference in complications rate between CFS (n = 1) and standard catheter (n = 2) ablations. CONCLUSIONS: There is no additional advantage of CFS catheters use over standard catheters during NF-RFCA of OT-VAs in terms of procedural effectiveness and safety.

Compound motor action potentials in transient and persistent phrenic nerve injury - metanalysis.

BACKGROUND: The right phrenic nerve is vulnerable to injury (PNI) during cryoballoon ablation (CBA) isolation of the right pulmonary veins. The complication can be transient or persistent. The reported incidence of PNI fluctuates from 4.73% to 24.7% depending on changes over time, CBA generation, and selected protective methods. M e t h o d s: Through September 2019, a database search was performed on MEDLINE, EMBASE, and Cochrane Database. In the selected articles, the references were also extensively searched. The study provides a comprehensive meta-analysis of the overall prevalence of PNI, assesses the transient to persistent PNI ratio, the outcome of using compound motor action potentials (CMAP), and estimated average time to nerve recovery. R e s u l t s: From 2008 to 2019, 10,341 records from 48 trials were included. Out of 783 PNI retrieved from the studies, 589 (5.7%) and 194 (1.9%) were persistent. CMAP caused a significant reduction in the risk of persistent PNI from 2.3% to 1.1% (p = 0.05; odds ratio [OR] 2.13) in all CBA groups. The mean time to PNI recovery extended beyond the hospital discharge was significantly shorter in CMAP group at three months on average versus non CMAP at six months (p = 0.012). CMAP (in contrast to non-CMAP procedures) detects PNI earlier from 4 to 16 sec (p <0.05; I2 = 74.53%) and 3 to 9o (p <0.05; I2 = 97.24%) earlier. C o n c l u s i o n s: Right PNI extending beyond hospitalization is a relatively rare complication. CMAP use causes a significant decrease in the risk of prolonged injury and shortens the time to recovery.

Left Ventricular Summit-Concept, Anatomical Structure and Clinical Significance.

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region. We postulate that the most dominant septal perforator (not the first septal perforator) should characterize the LVS definition. Abundant epicardial adipose tissue overlying the LVS myocardium may affect arrhythmogenic processes and electrophysiological procedures within the LVS region. The LVS is divided into two clinically significant regions: accessible and inaccessible areas. Rich arterial and venous coronary vasculature and a relatively dense network of cardiac autonomic nerve fibers are present within the LVS boundaries. Although the approach to the LVS may be challenging, it can be executed indirectly using the surrounding structures. Delivery of the proper radiofrequency energy to the arrhythmia source, avoiding coronary artery damage at the same time, may be a challenge. Therefore, coronary angiography or cardiac computed tomography imaging is strongly recommended before any procedure within the LVS region. Further research on LVS morphology and physiology should increase the safety and effectiveness of invasive electrophysiological procedures performed within this region of the human heart.

Non-fluoroscopic radiofrequency catheter ablation of right- and left-sided ventricular arrhythmias.

INTRODUCTION: Radiofrequency catheter ablation (RFCA) is an important method of treatment of ventricular arrhythmias (VAs). In the majority of RFCA, fluoroscopy is used, exposing patients and medical staff to all related side effects. Current experience of non-fluoroscopic (NF)-RFCA in VAs from the left side is limited. AIM: Analysis of safety and effectiveness of NF-RFCA of VAs from left- and right-sided cardiac chambers. MATERIAL AND METHODS: From 2014 to 2018, a group of 128 patients who underwent RFCA of VAs were retrospectively divided into two groups: NF-RFCA and fluoroscopic (F)-RFCA. Patients in each group were then subsequently subdivided into two groups based on VAs localization - left- (LS-Va) and right-sided (RS-Va) VAs. In all patients the CARTO Biosense Webster mapping system was used. RESULTS: In group 1 (NF-RFCA n = 88) 66 (75%) patients underwent RFCA of RS-Va and 22 (25%) of LS-Va. Early success was achieved in 89.8% (n = 79) and long term success in 81.8% (n = 72). In group 2 (F-RFCA n = 40) 19 patients (47.5%) had RFCA of RS-Va and 21 (52.5%) patients of LS-Va. Acute procedural success rate was 80% (n = 32) and long-term success 72.5% (n = 29). There were 4 (4.6%) perioperative complications in NF-RFCA and 2 (5%) in F-RFCA. Success rate, procedure time and complications were not significantly different between groups and subgroups in follow-up. CONCLUSIONS: NF-RFCA in VAs from the right and left cardiac chamber is safe and equally effective as F-RFCA, and it should be implemented as often as possible for protection of patients and electrophysiology staff.

[Reasons of recurrence and subjective arrhythmia feelings after successful RF AVNRT ablation].

Aim of the study was analysis of electrophysiological and clinical parameters related to increasement of recurrence risk of AVNRT and subjective heart feelings after successful RF ablation. Materials and methods: Retrospective analysis was made among patients after successful RF AVNRT ablation. Study group was 93 patients (F=63), mean age 46.7+15.9 (from 18 to 80y). Electrophysiological and physical parameters achieved during electrophysiological study was analysed. Using telephone monitoring and question survey patients were divided into 3 subgroups A ­ without symptoms, B ­ with subjective arrhythmia feelings and C with documented arrhythmia recurrence. Results: 6.4% patients (n=6) had documented arrhythmia recurrence AVNRT (subgroup C); women 100% (n=6), mean age 43.5±14 years. 43% of patients (n=40) after successful RF ablation had subjective feelings of heart palpitations of a different kind (subgroup B); women 68% (n=32), mean age 42.8±14 years. 51% (n=47) of patients didn't feel any arrhythmia (subgroup A); women 64% (n=36), mean age 50.7±17 years. Conclusions: Factors related to increased risk of arrhythmia recurrence was: atypical forms of tachycardia, shorter tachycardia cycle, slow pathway modification, low mean power during RF ablation. Among patients without documented arrhythmia recurrence: lower age, higher time from the beginning arrhythmia until ablation procedure and Wenckebach Point cycle length shorter predispose to inadequate subjective arrhythmia feelings after successful RF ablation.

Vitamin K antagonists favourably modulate fibrin clot properties in patients with atrial fibrillation as early as after 3days of treatment: Relation to coagulation factors and thrombin generation.

INTRODUCTION: Atrial fibrillation (AF) increases the risk of thromboembolism that is reduced by vitamin K antagonists (VKAs). We sought to investigate changes in plasma fibrin clot phenotype at the onset of oral anticoagulation. MATERIALS AND METHODS: Forty consecutive AF patients (aged 45-83 years, CHA2DS2-VASc score 3.0±1.5) who started therapy with warfarin or acenocoumarol were studied. Plasma fibrin clot permeability (Ks), clot lysis time (CLT), along with clotting factors (F), thrombin generation (TG) profiles and protein C (PC) levels were determined on days 3, 5, 7, 28 and 56±1 since the first dose. RESULTS: AF patients had 16% higher median of Ks and 15% lower median of CLT as early as on day 3 of VKA therapy compared with the baseline (both p<0.001), reaching the plateau values on day 7 and 5, respectively. Higher Ks values on days 1 and 3 were found in AF patients with further stable anticoagulation (both p<0.05). Moreover, FIX explained 32% of the total variability in Ks. Multivariate analysis adjusted for potential confounders including time as a predictor showed that vitamin K-dependent (VKD) factors, PC and TG parameters were the predictors of Ks (all p<0.0001), while only the lag phase of TG and thrombin peak predicted CLT (both p<0.05) in AF patients. Regression analysis of time-series showed however, that CLT was also predicted by VKD factors and PC (all p<0.05). CONCLUSIONS: Plasma fibrin clot properties in AF patients are favourably modified as early as after 3days of VKA administration, which might contribute to antithrombotic effectiveness.

Effectiveness of atrial versus atrioventricular pacing for sick sinus syndrome during long-term follow-up.

BACKGROUND: According to the current guidelines, atrioventricular (DDD) pacing is superior to atrial pacing (AAI) in the treatment of sick sinus syndrome (SSS). AIM: To compare outcomes of AAI and DDD pacing in patients with SSS during long-term follow-up. METHODS: We studied 809 patients, including 86 patients in the AAI group (57 women, mean age 65 ± 15 years) and 723 patients in the DDD group (406 women, mean age 71.5 ± 10 years). Evaluation of outcomes of AAI and DDD pacing in SSS was based on the analysis of medical records of patients who underwent pacemaker implantation. RESULTS: Average duration of follow-up was 52 ± 25 months. In the AAI group, 63 of 86 patients remained without intervention. In the DDD group, 661 of 723 patients did not require surgical intervention. Overall, 105 patients died, including 13 in the AAI group and 92 in the DDD group (p = 0.4516). In the AAI group, a high degree atrioventricular block occurred on average after 46.3 ± 8.8 months and its incidence was estimated at 0.85% per year. Atrial fibrillation (AF) developed in 8 patients in the AAI group and 81 patients in the DDD group (p = 0.23). Among aetiological factors of an increased risk of developing AF, only the presence of tachycardia-bradycardia syndrome (hazard ratio [HR] 11.31) and the absence of antiarrhythmic therapy (HR 4.23) significantly increased the risk of AF. Urgent reoperation was needed in 23 patients in the AAI group and 62 patients in the DDD group (p < 0.01). Log-rank test analysis showed a significant effect of the development of AF on the risk of reoperation in this group (p = 0.0420). Lead-related complications were noted in 6 patients in the AAI group and 49 patients in the DDD group (p = 0.94). After 45 months, the risk of reoperation in the AAI group increased significantly due to a need for ventricular lead implantation. CONCLUSIONS: 1. Atrial stimulation is safe in SSS but it may be associated with an increased risk of ventricular lead implantation if atrioventricular block or persistent AF with slow ventricular rate develops. 2. DDD and AAI groups did not differ significantly in terms of survival, development of persistent AF, and lead-related complications. 3. Tachycardia-bradycardia syndrome and the lack of antiarrhythmic treatment with beta-blocker and amiodarone increased the risk of persistent AF during long-term follow-up. 4. A higher rate of reoperations in patients with AAI systems, related mainly to development of persistent AF, especially after the fourth year of follow-up, may justify DDD system implantation in SSS.

Assays of fibrin network properties altered by VKAs in atrial fibrillation - importance of using an appropriate coagulation trigger.

Atrial fibrillation (AF) is a prothrombotic condition, involving increased thrombin generation and fibrinogen concentrations. Vitamin K antagonists (VKAs) prevent arterial thromboembolism if optimal anticoagulation is achieved by individualised drug doses, assessed by determining the Prothrombin time-related International Normalized Ratio (Pt-INR). There is evidence that formation of tight-laced fibrin networks is pathogenic in prothrombotic diseases. This study was performed among AF patients, to test whether long-term treatment with VKAs affects the structure of fibrin networks, and whether the effect is altered by employing different coagulation triggers: exogenous thrombin (1 IU/ml), 10 pM tissue factor (TF) or a commercial Pt-INR reagent (containing 400-fold more TF). In the thrombin-based method, fibrin network porosity (scanning electron microscopy) and liquid permeability (flow measurements) correlated inversely to fibrinogen concentrations, while positive correlations to the degree of anticoagulation were shown with the Pt-INR reagent. In the method with 10 pM TF, the two above relationships were detected, though the influence of Pt-INR was more profound than that of fibrinogen concentrations. Moreover, greater shortening of clot lysis time (CLT) arose from more permeable clots. As a coagulation trigger, 10 pM TF vs exogenous thrombin or the Pt-INR reagent is more informative in reflecting the in vivo process from thrombin generation to fibrin formation. Since fibrin network permeability rose in parallel to elevations of INR and shortening of CLT in AF patients, antithrombotic effects on prevention of thrombotic complications may be achieved from impairment of thrombin generation, resulting in formation of permeable clots susceptible to fibrinolysis.

[Ablation of slow pathway in a patient with persistent left superior vena cava]. / Ablacja sciezki wolnej u pacjentki z przetrwala lewa zyla glówna górna

We describe a case of successful radiofrequency ablation of slow pathway in a 54 year-old woman with persistent left superior vena cava. The ablation was performed using anatomical approach, outside the ostium of coronary sinus.

[Evaluation of the early effectiveness and late arrhythmia recurrences subjectively experienced by the patient after RF ablation of accessory pathway in Wolf-Parkinson-White syndrome depending on it's localization and the electrical parameters of ablation--own observation]. / Ocena skutecznosci wczesnej oraz póznych nawrotów arytmii subiektywnie odczuwanych przez pacjenta po ablacji RF drogi dodatkowej w zespole Wolfa-Parkinsona-White'a w zaleznosci od lokalizacji oraz parametrów elektrycznych ablacji--obserwacje wlasne.

UNLABELLED: Nowadays, radiofrequency ablation (RF) is recommended treatment method of atrioventricular reentrant tachycardia associated with accessory pathway. This procedure is characterised by high early and late efficacy and low risk of complication. The aim of this study was to evaluate early effectiveness and late arrhythmia recurrences subjectively experienced by the patient after RF ablation of accessory pathway in Wolf-Parkinson-White Syndrome, depending on it's localization and the electrical parameters of ablation. MATERIAL AND METHODS: Seventy two patient in age 13-79 (35 +/- 15,3) who had RF ablation of accessory pathway preformed were included in this study. Localization of the pathway, electrical parameters of ablation and early effectiveness of the procedure was assessed retrospectively. Group of patients who had successful ablation (n = 57) were asked about recurrence of heart palpitation after minimum 6 months from the procedure and further. Additionally, information about comorbidities and medication used by patients was collected. RESULTS: Septal localization of accessory pathway was most frequent (59,7%) in study group (n = 72). Early effectiveness was achieved in 80% of patient. Electrical ablation parameters were similar in a group with successful (n = 57) and unsuccessful procedure (n = 15) with exception of numbers of RF application (14 vs 30). In a late observation, 59,09% of the patients did not experienced recurrence of heart palpitation. CONCLUSIONS: In accessory pathway with difficult anatomy access, increased number of RF application do not increase procedure effectiveness. Subjective late effect of the ablation reported by the patient is lower than after electrophysiological study verification. Lack of correlation between pathway localization and early effectiveness of the ablation or late recurrence of heart palpitation reported by the patient.

[Venous thrombosis as a complication of pacemaker implantation--own observations]. / Zakrzepica zylna jako powiklanie po wszczepieniu rozrusznika serca--wlasne obserwacje.

UNLABELLED: Thrombosis is a fairly rare, yet dangerous complication of pacemaker implantation. It may occur in various time intervals after the actual implantation procedure. The risk factors are as follows: inflammation or injury, vein anomalies, arrhythmia, venous stenosis. The aim of the study was to assess the risk factors for venous thrombosis, determine the interrelationship between venous thrombosis and the level of select inflammatory and pro-thrombotic factors, as well as to evaluate the actual impact of pacemaker implantation procedure within a group of patients with permanent heart stimulation system. MATERIAL AND METHODS: The study involved 48 patients with permanent heart stimulation system, divided into 2 groups. Group A (18 F, 20 M; mean age 71.7 +/- 13.6 years) consisted of patients who had up to 3 thrombotic risk factors, whereas group B (2 F, 8 M; mean age 71.6 +/- 7.5 years) comprised the patients with more than 5 thrombotic risk factors. All patients were subsequently followed up for 18 months. Prior to pacemaker implantation the following factors were assessed in each patient: specific indications for pacemaker implantation, overall clinical condition, coexisting diseases, history of tobacco smoking, medications used prior to the procedure (anti-platelet, anti-coagulation), history of thrombotic or infectious complications, previous temporary heart stimulation. A transthoracic echocardiogram (TTE) and an ultrasound examination of the veins in both upper extremities were carried out. The levels of: D-dimers, fibrinogen, interleukin-6 (IL-6), hsCRP, TF and PAI-1 were determined in the venous blood. During the pacemaker implantation procedure the actual access to the veins and possible venous anomalies were assessed. After the pacemaker implantation, the TTE and venous ultrasound examination were carried out after 6 and 12 months, blood analyses for up to 7 days after the implantation, and subsequently after 6 and 12 months. RESULTS: Patients in group B had significantly lower left ventricle ejection fraction and larger left ventricle end diastolic diameter than group A patients. In 3 patients in group B (which made up 6.25% of the study population), symptomatic venous thrombosis occurred after a 12-month observation period (mean 13.06 months). Initially, the levels of IL-6, hsCRP, TF, PAI-1, fibrinogen and D-dimers were considerably higher in group B, in comparison to group A. In all patients the levels of the above referenced factors kept on increasing for up to 7 days after the procedure. In group A they subsequently decreased, whereas in group B they kept on growing. In group B a significant negative correlation was observed between the left ventricle ejection fraction and the inflammatory and thrombotic factors under study. The lower the ejection fraction, the higher actually were their values. CONCLUSIONS: In patients with more than 5 thrombosis risk factors, the increased levels of IL-6, hsCRP, fibrinogen, D-dimers, TF and PAI-1 were observed. A pacemaker implantation procedure is believed to increase both thrombotic and inflammatory state in a patient for up to 7 days after the procedure. In patients prone to thrombosis, a negative correlation between the ejection fraction and the levels of hsCRP, D-dimers, TF and PAI-1 were observed.