Randomized comparison of atrioventricular node re-entry tachycardia and atrial flutter catheter ablation with and without fluoroscopic guidance: ZeroFluoro study.

AIMS: Interventional cardiology procedures may expose patients and staff to considerable radiation doses. We aimed to assess whether exposure to ionizing radiation during catheter ablation of supraventricular tachycardia (SVT) can be completely avoided. METHODS AND RESULTS: In this prospective randomized study, patients with SVT (atrioventricular re-entrant tachycardia n = 94, typical atrial flutter n = 29) were randomly assigned in a 1:1 ratio to catheter ablation with conventional fluoroscopic guidance (CF group) or with the EnSite Precision mapping system [zerofluoro (ZF) group]. Acute procedural parameters, increased stochastic risk of cancer incidence and 6-month follow-up data were assessed. Between May 2019 and August 2020, 123 patients were enrolled. Clinical parameters were comparable. Median procedural time was 60.0 and 58.0 min, median fluoroscopy time and estimated median effective dose were 240 s vs. 0 and 0.38 mSv vs. 0 and arrhythmia recurrence was 5% and 7.9% in the CF and ZF groups, respectively. The acute success rate was 98.4% in both groups. No procedure-related complications were reported. At an average age of 55.5 years and median radiation exposure of 0.38 mSv, the estimate of increased incidence was approximately 1 in 14 084. The estimated mortality rate was 1 per 17 857 exposed persons. CONCLUSIONS: The procedural safety and efficacy of the zero-fluoroscopic approach are similar to those of conventional fluoroscopy-based ablation for atrioventricular nodal re-entrant tachycardia and atrial flutter. Under the assumption of low radiation dose, the excessive lifetime risk of malignancy in the CF group due to electrophysiology procedure is reasonably small, whilst totally reduced in zero fluoroscopy procedures.

Mid-term success rate of single stage hybrid ablation of persistent and long-term persistent atrial fibrillation.

INTRODUCTION: Single stage thoracoscopic radiofrequency ablation (RFA) is a treatment method for persistent and long-term persistent atrial fibrillation (AF) offering the possibility for patients otherwise inconsolable by conventional catheter RFA. We present a pilot group of patients after the introduction of the new method at our clinical center. Patients group: A total of 52 patients aged 61.82 ± 9.7 years underwent single stage hybrid ablation (thoracoscopic isolation of pulmonary veins and box lesion followed by catheter verification of the surgical procedure effectivness) for symptomatic persistent and long-term persistent AF with significantly dilated left atrium 57.9 ± 11.0mm in the period September 2016-March 2019. RESULTS: The median duration of the procedure was 232 minutes and the median duration of hospitalization was 10 days. At discharge, 52 patients (100%) had sinus rhythm. 48 of 52 patients (92.3%) had a 6-month follow-up. 41 of 48 (85.4%) and 38 of 44 (86.4%) of patients were AF free at 3-month and 6-month follow-up, respectively. Acute complications were: one left atrial perforation resolved successfully by suture and one transient ischaemic attack without permanent sequelae. Late complications involved one massive pulmonary embolization and an atrioesophageal fistula. There was no periprocedural myocardial infarction or stroke with permanent sequelae. CONCLUSION: Hybrid thoracoscopic-catheter ablation performed during one procedure is an effective and relatively safe mini-invasive method of treatment for long-term persistent atrial fibrillation.

Bipolar ablation with contact force-sensing of swine ventricles shows improved acute lesion features compared to sequential unipolar ablation.

INTRODUCTION: Despite technical progress, ventricular tachycardia (VT) recurrence after unipolar ablation remains relatively high (12%-47%). Bipolar ablation has been proposed as an appealing solution that may overcome limitations associated with unipolar ablation settings. We designed an animal study to compare bipolar (BPA) vs sequential unipolar ablation (UPA) using contact force-sensing technology on both ablation catheters. METHODS: Twenty large white female pigs (6-months-old, 50-60 kg) underwent multiple RF ablations (30 W, 60 seconds, 30 mL/min irrigation) on the ventricular myocardium from the epicardial and endocardial sides. The hearts were fixed and scanned with high-resolution cardiac magnetic resonance imaging. Thermal lesions were located and characterized in volume, depth, width, and transmurality. RESULTS: Lesion volume was calculated as the sum of epicardial or endocardial conjoined/isolated lesions at one location. Linear dimensions (width and depth) were measured twice for each location, on the endocardial and epicardial side. We evaluated 35 lesions across the intraventricular septum (UPA, N = 17 vs BPA, N = 18). No difference in volume, linear dimensions or impedance drop was observed in this area between UPA and BPA. However, BPA required half RF time and showed an increased transmurality trend. We then analyzed 73 lesions from the endocardial side (UPA, N = 35 vs BPA, N = 38) and 50 from the epicardial side (UPA, N = 11 vs BPA N = 39) of the ventricular free walls. Lesion transmurality was markedly improved by BPA (P = .030, odds ratio, 23.73 [4.71,31.96]). Ventricular BPA lesions were significantly deeper on the epicardial side (P < .0001) and endocardial side (P = .015). CONCLUSION: Bipolar ablation is more likely to create transmural and epicardial lesions in the ventricle wall. Half the time is needed for the creation of comparably deep and large lesions.

[Novelties in the treatment of heart failure]. / Novinky v lécbe srdecního selhání.

Heart failure (HF) is a complex clinical syndrome which is manifested by characteristic symptoms and objective signs of cardiac insufficiency. The incidence of HF, particularly its chronic form, is estimated 0.4-2 % in the central and western Europe, with an increase in higher age groups, affecting 10-20 % of the population aged over 80. With respect to its growing incidence and prevalence, novel modalities of pharmacological and non-pharmacological treatment are being developed in order to improve quality of life and survival of the affected patients. This review based on up-to-date guidelines focuses in the first part on brief description of the possibilities of diagnosing heart failure, including the novelties arising out from the latest clinical and preclinical studies (such as soluble ST2, FSTL1, etc), further it concentrates on innovations in pharmacological treatment of chronic (ivabradine, ARNI, gliflozins) and acute (ularitide, serelaxin, nesiritide) HF. The last part provides an overview of available non-pharmacological HF therapeutics options (modulation of cardiac contraction, influencing the activity of sympathetic and parasympathetic nervous systems and permanent and temporary device support).Key words: ARNI - ECMO - gliflozins - heart failure - modulation of sympathetic and parasympathetic nervous systems - sacubitril-valsartan - therapy.

Reduced Radiation Exposure Protocol during Computer Tomography of the Left Atrium Prior to Catheter Ablation in Patients with Atrial Fibrillation.

(1) Background: Computer tomography (CT) is an imaging modality used in the pre-planning of radiofrequency catheter ablation (RFA) procedure in patients with cardiac arrhythmias. However, it is associated with a considerable ionizing radiation dose for patients. This study aims to develop and validate low-dose CT scanning protocols of the left atrium (LA) for RFA guidance. (2) Methods: 68 patients scheduled for RFA of atrial fibrillation were sequentially assigned to four groups of ECG-gated scanning protocols, based on the set tube current (TC): Group A (n = 20, TC = 33 mAs), Group B (n = 18, TC = 67 mAs), Group C (n = 10, TC = 135 mAs), and control Group D (n = 20, TC = 600 mAs). We used a 256-row multidetector CT with body weight-dependent tube voltage of 80 kVp (<70 kg), 100 kVp (70−90 kg), and 120 kVp (>90 kg). We evaluated scanning parameters including radiation dose, total scanning procedure time and signal-to-noise ratio (SNR). (3) Results: The average effective radiation dose (ED) was lower in Group A in comparison to Group B, C and D (0.83 (0.76−1.10), 1.55 (1.36−1.67), 2.91 (2.32−2.96) and 9.35 (8.00−10.04) mSv, p < 0.05). The total amount of contrast media was not significantly different between groups. The mean SNR was 6.5 (5.8−7.3), 7.1 (5.7−8.2), 10.8 (10.1−11.3), and 12.2 (9.9−15.7) for Group A, B, C and D, respectively. The comparisons of SNR in group A vs. B and C vs. D were without significant differences. (4) Conclusions: Optimized pre-ablation CT scanning protocols of the LA can reduce an average ED by 88.7%. Three dimensional (3D) models created with the lowest radiation protocol are useful for the integration of electro-anatomic-guided RFA procedures.

Comparison of atrial fibrillation ablation efficacy using remote magnetic navigation vs. manual navigation with contact-force control.

AIMS: This study aims to compare procedural parameters and clinical efficacy of remote magnetic navigation (RMN) vs. manual navigation (MAN) approach for radiofrequency ablation (RFA) in patients with atrial fibrillation (AF). METHODS: 146 patients with AF were enrolled in the study. In the RMN group (n=57), patients were treated with the CARTO® 3 in combination with the Niobe ES system. In the MAN group (n=89), ablation was performed with the EnSite Velocity and TactiCath™ Quartz catheter with direct contact force measurement. Procedural time, ablation time, fluoroscopy time, radiation dose and ablation counts were measured and compared between the groups. Recurrence of AF was evaluated after 6 months of follow-up. RESULTS: Mean procedure times (236.87±64.31 vs. 147.22±45.19 min, P<0.05), counts of RF applications (74.30±24.77 vs. 49.15±20.33, P<0.05) and total RFA times (4323.39±1426.69 vs. 2780.53±1157.85 s, P<0.05) were all significantly higher in the RMN than in the MAN group, respectively. In the same order, mean X-ray dose (9722.6±7507.4 vs. 8087.9±6051.5 mGy/cm2, P=0.12) and mean total X-ray exposure time (8.07±4.20 vs. 9.54±5.47 min, P=0.08) were not statistically different. At 6-month follow-up, freedom from AF was similar in RMN and MAN group for paroxysmal (60.8% and 73%, respectively, P=0.42) and persistent AF (69.6% and 75.0%, respectively, P=0.77). CONCLUSIONS: Due to the fact that mid-term clinical outcomes showed no significant differences in AF recurrences between groups and manual ablation strategy provided more favorable results regarding acute procedural parameters, we can conclude that the remote magnetic navigation is not superior to the manual approach.

Use of Bipolar Radiofrequency Catheter Ablation in the Treatment of Cardiac Arrhythmias.

BACKGROUND: Arrhythmia management is a complex process involving both pharmacological and non-pharmacological approaches. Radiofrequency ablation is the pillar of nonpharmacological arrhythmia treatment. Unipolar ablation is considered to be the gold standard in the treatment of the majority of arrhythmias; however, its efficacy is limited to specific cases. In particular, the creation of deep or transmural lesions to eliminate intramurally originating arrhythmias remains inadequate. Bipolar ablation is proposed as an alternative to overcome unipolar ablation boundaries. RESULTS: Despite promising results gained from in vitro and animal studies showing that bipolar ablation is superior in creating transmural lesions, the use of bipolar ablation in daily clinical practice is limited. Several studies have been published showing that bipolar ablation is effective in the treatment of clinical arrhythmias after failed unipolar ablation, however, there is inconsistency regarding the safety of bipolar ablation within the available research papers. According to research evidence, the most common indications for bipolar ablation use are ventricular originating rhythmic disorders in patients with structural heart disease resistant to standard radiofrequency ablation. CONCLUSION: To allow wider clinical application the efficiency and safety of bipolar ablation need to be verified in future studies.

Statins decrease leptin expression in human white adipocytes.

Statin use is associated with increased calorie intake and consequent weight gain. It is speculated that statin-dependent improvements in lipid profile may undermine the perceived need to follow lipid-lowering and other dietary recommendations leading consequently to increased calorie intake. However, increases in calorie intake in statin users may also be related to statin-dependent decreases in satiety factors such as leptin, an adipocyte-derived adipokine. The objective of our study was to examine the direct effects of statins on leptin expression. Adipocytes are the main source of circulating leptin. Therefore, we examined the effects of atorvastatin and simvastatin on leptin expression in cultured human white adipocytes. We show that treatment of white adipocytes with simvastatin and atorvastatin decreases leptin mRNA expression (simvastatin: P = 0.008, atorvastatin: P = 0.03) and leptin secretion (simvastatin: P = 0.0001, atorvastatin: P = 0.0001). Both simvastatin and atorvastatin mediate decreases in leptin expression via extracellular-signal-regulated kinases 1/2 and peroxisome proliferator-activated receptor gamma pathways (simvastatin: P = 0.01, atorvastatin: P = 0.026). Additionally, statin treatment also induced expected increases in adiponectin, while decreasing monocyte chemoattractant protein 1 (MCP1) mRNA. Furthermore, statins increased secretion of both total as well as high molecular weight adiponectin while decreasing MCP1 secretion. To conclude, statins act directly on human white adipocytes to regulate adipokine secretion and decrease leptin expression. Leptin is an important satiety factor. Hence, statin-dependent decreases in leptin may contribute, at least in part, to increases in food intake in statin users.

Phosphodiesterase 5 Inhibitor Use in Men With Hypertrophic Cardiomyopathy.

The prevalence of sexual dysfunction (SD) in men with hypertrophic cardiomyopathy (HC) remains unknown, yet its clinical relevance may be high given that its treatment-phosphodiesterase 5 inhibitors (PDE5i)-can increase the left ventricular outflow tract pressure gradient. In this retrospective study, we evaluated the medical records of consecutively seen men with HC for the evidence of SD (defined as SD diagnosis noted in the medical record, the use of medications unique for SD, or SD reported by the patient on a routine clinical questionnaire). Of the 283 consecutively seen men with HC (mean age 52.9 ± 14.1 years), 63 patients (22%) with SD were identified. Of those with SD, 38% were recorded as regularly using PDE5i. In conclusion, SD and the use of PDE5i present a relatively common occurrence in men with HC, and further studies are needed to develop an evidence-guided algorithm for safe implementation of SD therapies in this most common inherited cardiomyopathy.

Effects of Atorvastatin (80 mg) Therapy on Quantity of Epicardial Adipose Tissue in Patients Undergoing Pulmonary Vein Isolation for Atrial Fibrillation.

Epicardial adipose tissue (EAT) has been recognized as a sensitive marker of cardiometabolic risk. Recent evidence suggests efficacy of long-term statin therapy in reducing EAT in patients with coronary artery disease. Whether short-term statin therapy is associated with changes in the volume of EAT is currently unknown. A cohort of patients with atrial fibrillation who underwent pulmonary vein isolation were randomized to receive either 80 mg/day of atorvastatin (n = 38, 32 men, age 56 ± 11 years) or placebo (n = 41, 33 men, age 56 ± 10 years) for a 3-month period. EAT volume was assessed by cardiac computed tomography at baseline and at follow-up. Patients randomized to statin treatment exhibited a modest but significant decrease in median EAT volume (baseline vs follow-up: 92.3 cm(3) [62.0 to 133.3] vs 86.9 cm(3) [64.1 to 124.8], p <0.05), whereas median EAT remained unchanged in the placebo group (81.9 cm(3) [55.5 to 110.9] vs 81.3 cm(3) [57.1 to 110.5], p = NS). Changes in median systemic inflammatory markers and lipid profile were also seen with statin treatment: C-reactive protein (2.4 mg/L [0.7 to 3.7] vs 1.1 mg/L [0.5 to 2.7], p <0.05), total cholesterol (186 mg/dL [162.5 to 201] vs 123 mg/dL [99 to 162.5], p <0.001), and low-density lipoprotein cholesterol (116 mg/dL [96.5 to 132.5] vs 56 [40.5 to 81] mg/dL, p <0.001) diminished, whereas median body mass index did not change (27.8 kg/m(2) [25 to 30] versus 27.6 kg/m(2) [25.7 to 30.5], p = NS). No variations occurred in the placebo group. In conclusion, short-term intensive statin therapy significantly reduced the volume of EAT in patients with atrial fibrillation.

Independent component analysis and decision trees for ECG holter recording de-noising.

We have developed a method focusing on ECG signal de-noising using Independent component analysis (ICA). This approach combines JADE source separation and binary decision tree for identification and subsequent ECG noise removal. In order to to test the efficiency of this method comparison to standard filtering a wavelet- based de-noising method was used. Freely data available at Physionet medical data storage were evaluated. Evaluation criteria was root mean square error (RMSE) between original ECG and filtered data contaminated with artificial noise. Proposed algorithm achieved comparable result in terms of standard noises (power line interference, base line wander, EMG), but noticeably significantly better results were achieved when uncommon noise (electrode cable movement artefact) were compared.

Relation of chronic obstructive pulmonary disease to atrial and ventricular arrhythmias.

Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular morbidity and mortality, yet the exact pathophysiological links remain unclear. Whether the presence and severity of COPD are associated with atrial or ventricular arrhythmias recorded on continuous electrocardiographic monitoring is unknown. We identified consecutive adult patients who underwent clinically indicated pulmonary function testing as well as 24-hour Holter monitoring at the Mayo Clinic, Rochester, from 2000 to 2009. Demographic data and relevant co-morbidities were gathered from the electronic medical record; severity of COPD was classified according to the GOLD classification, and arrhythmias were classified in concordance with the current clinical guidelines. From 7,441 patients who were included (age 64±16 years, 49% woman, 92% Caucasian), COPD was diagnosed in 3,121 (41.9%). Compared with those without COPD, the presence and severity of COPD were associated with increased likelihood of atrial fibrillation/atrial flutter (AF/AFL; 23.3% vs 11.0%, respectively, p<0.0001), nonsustained ventricular tachycardia (NSVT; 13.0% vs 5.9%, respectively, p<0.0001), and sustained ventricular tachycardia (0.9% vs 1.6%, respectively, p<0.0001). COPD remained a significant predictor of AF/AFL and NSVT (p<0.0001 and p<0.0001, respectively) after adjusting for age, gender, tobacco use, obesity, hypertension, coronary artery disease, heart failure, diabetes, anemia, cancer, chronic kidney disease, and rate/rhythm control medications. In conclusion, the independent association between the presence and severity of COPD and arrhythmias (AF/AFL and NSVT) provides further insight into the markedly increased cardiovascular mortality of patients with COPD. Further studies should explore which anti-arrhythmic strategies would best apply to the patients with COPD.