Atrial fibrillation ablation workflow optimization facilitated by high-power short-duration ablation and high-resolution mapping.

AIMS: Pulmonary vein isolation (PVI) for catheter ablation of atrial fibrillation (AF) is a time-demanding procedure. High-power short-duration (HPSD) ablation protocols and high-density mapping catheters have recently been introduced to clinical practice. We investigated the impact of high-density mapping and HPSD ablation protocols on procedural timing, efficacy, and safety by comparing different standardized set-ups. METHODS AND RESULTS: Three electrophysiology (EP) laboratory set-ups were analysed: (i) circular catheter for mapping and HPSD ablation with 30/35 W guided by an ablation index (AI); (ii) pentaspline catheter for mapping an HPSD ablation with 50 W guided by an AI; and (iii) pentaspline catheter for mapping and HPSD ablation with 90 W over 4 s using a novel ablation catheter. All patients underwent PVI without additional left atrial ablation strategies. Procedural data and operating intervals in the EP laboratory were systematically analysed. Three hundred seven patients were analysed (30/35 W AI: n = 102, 50 W AI: n = 102, 90 W/4 s: n = 103). Skin-to-skin times [105.3 ± 22.7 (30/35 W AI) vs. 81.4 ± 21.3 (50 W AI) vs. 69.5 ± 12.2 (90 W/4 s) min, P ≤ 0.001] and total laboratory times (132.8 ± 42.1 vs. 107.4 ± 25.7 vs. 95.2 ± 14.0 min, P < 0.001) significantly differed among the study groups. Laboratory interval analysis revealed significant shortening of mapping and ablation times. Arrhythmia-free survival after 12 months was not different among the study groups (log-rank P = 0.96). CONCLUSION: The integration of high-density mapping and HPSD protocols into an institutional AF ablation process resulted in reduced procedure times without compromising safety or efficacy.

Magnetic resonance assessment of left atrial scar formation following a novel very high-power short-duration workflow for atrial fibrillation ablation.

AIMS: Atrial fibrillation (AF) ablation protocols using energy delivery with very high power and short duration (vHPSD) have been introduced to improve lesion formation. This study reports procedural data of vHPSD ablation in AF patients and analyses characteristics of ablation-induced left atrial (LA) scar formation from cardiac magnetic resonance imaging (MRI). METHODS AND RESULTS: Sixty consecutive patients undergoing index pulmonary vein isolation following our institutional Q4U-AF workflow were prospectively enrolled. Ablation was conducted using a contact force sensing catheter allowing for vHPSD ablation using a temperature-controlled ablation mode. Thirty patients underwent cardiac late gadolinium enhancement MRI of the LA 3 months after ablation to assess LA scar. Mean procedural duration was 66.5 ± 14.8 min. Mean ablation time was 4.7 ± 0.9 min with a mean number of 69.9 ± 14.2 applications. First-pass isolation was achieved in 51 patients (85%) for the right pulmonary veins (RPVs), in 37 patients (61.7%) for the left pulmonary veins (LPVs), and in 34 patients (56.7%) for both pulmonary veins (PVs). Magnetic resonance imaging at 3 months post-ablation demonstrated a mean scar width of 14.4 ± 2.6 mm around RPVs and 11.9 ± 1.9 mm at LPVs (P > 0.05). Complete PV encirclement was observed in 76.7% for RPVs, in 76.7% for LPVs, and in 66.7% for both PV pairs. During a mean follow-up of 4.7 ± 1.4 months, arrhythmia recurrence was observed in 3.3% of the patients. CONCLUSION: Pulmonary vein isolation following a novel vHPSD workflow resulted in short procedure duration and high acute and mid-term efficacy. Magnetic resonance imaging demonstrated durable and transmural PV lesions with homogeneous and contiguous scar formation.

EASY-WPW: a novel ECG-algorithm for easy and reliable localization of manifest accessory pathways in children and adults.

AIMS: Accessory pathway (AP) ablation is a standard procedure for the treatment of Wolff-Parkinson-White syndrome (WPW). Twelve-lead electrocardiogram (ECG)-based delta wave analysis is essential for predicting ablation sites. Previous algorithms have shown to be complex, time-consuming, and unprecise. We aimed to retrospectively develop and prospectively validate a new, simple ECG-based algorithm considering the patients' heart axis allowing for exact localization of APs in patients undergoing ablation for WPW. METHODS AND RESULTS: Our multicentre study included 211 patients undergoing ablation of a single manifest AP due to WPW between 2013 and 2021. The algorithm was developed retrospectively and validated prospectively by comparing its efficacy to two established ones (Pambrun and Arruda). All patients (32 ± 19 years old, 47% female) underwent successful pathway ablation. Prediction of AP-localization was correct in 197 patients (93%) (sensitivity 92%, specificity 99%, PPV 96%, and NPV 99%). Our algorithm was particularly useful in correctly localizing antero-septal/-lateral (sensitivity and specificity 100%) and posteroseptal (sensitivity 98%, specificity 92%) AP in proximity to the tricuspid valve. The accuracy of EASY-WPW was superior compared to the Pambrun (93% vs. 84%, P = 0.003*) and the Arruda algorithm (94% vs. 75%, P < 0.001*). A subgroup analysis of children (n = 58, 12 ± 4 years old, 55% female) revealed superiority to the Arruda algorithm (P < 0.001*). The reproducibility of our algorithm was excellent (Ï°>0.8; P < 0.001*). CONCLUSION: The novel EASY-WPW algorithm provides reliable and accurate pre-interventional ablation site determination in WPW patients. Only two steps are necessary to locate left-sided AP, and three steps to determine right-sided AP.

Lesion formation following pulsed field ablation for pulmonary vein and posterior wall isolation.

BACKGROUND: Pulsed field ablation (PFA) results in unique lesion formation, but there is lack of in-vivo validation in terms of scar formation following atrial fibrillation (AF) ablation. OBJECTIVE: We aimed to access atrial lesion formation based on late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) following PFA for pulmonary vein (PV) and posterior wall isolation (PWI). METHODS: AF ablation was performed in 10 patients using a 31 mm pentaspline PFA catheter. After pulmonary vein isolation (PVI; n = 8 PFA-applications/ PV; n = 4 in basket and n = 4 in flower configuration), another eight applications in flower configuration were conducted for concomitant PWI. Patients underwent LGE CMR 3 months after ablation aiming for quantification of left atrial (LA) scar. RESULTS: Acute procedural success was achieved in all patients. Mean procedure duration was 62 ± 7 min. and mean LA dwell time of the PFA catheter was 13 ± 2 min. Mean post ablation total LA scar burden was 8.1 ± 2.1% and mean scar width was 12.8 ± 2.1 mm. At the posterior LA, 22.6 ± 2.2% of the anatomical segment resulted in chronic scar tissue, concentrated at the PW. Postablation CMR found no evidence for PV stenosis or collateral damage of adjacent structures. At 7 months of follow-up, 9/10 patients (90%) were free from arrhythmia recurrence. CONCLUSION: PFA for AF resulted in durable and transmural atrial scar tissue at the PVs and PW. LGE CMR found a very homogeneous and contiguous lesion pattern with no signs for collateral damage.

The individual relationship between atrial fibrillation sources from CARTOFINDER mapping and atrial cardiomyopathy: The catch me if you can trial.

BACKGROUND: Targeting individual sources identified during atrial fibrillation (AF) has been used as an ablation strategy with varying results. OBJECTIVE: Aim of this study was to evaluate the relationship between regions of interest (ROIs) from CARTOFINDER (CF) mapping and atrial cardiomyopathy from late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR). METHODS: Twenty consecutive patients underwent index catheter ablation for persistent AF (PERS AF). Pre-processed LGE CMR images were merged with the results from CF mapping to visualize harboring regions for focal and rotational activities. Atrial cardiomyopathy was classified based on the four Utah stages. RESULTS: Procedural success was achieved in all patients (n = 20, 100%). LGE CMR revealed an intermediate amount of 21.41% ± 6.32% for LA fibrosis. ROIs were identified in all patients (mean no ROIs per patient n = 416.45 ± 204.57). A tendency towards a positive correlation between the total amount of atrial cardiomyopathy and the total number of ROIs per patient (regression coefficient, ß = 10.86, p = .15) was observed. The degree of fibrosis and the presence of ROIs per segment showed no consistent spatial correlation (posterior: ß = 0.36, p-value (p) = .24; anterior: ß = -0.08, p = .54; lateral: ß = 0.31, p = 39; septal: ß = -0.12; p = .66; right PVs: ß = 0.34, p = .27; left PVs: ß = 0.07, p = .79; LAA: ß = -0.91, p = .12). 12 months AF-free survival was 70% (n = 14) after ablation. CONCLUSION: The presence of ROIs from CF mapping was not directly associated with the extent and location of fibrosis. Further studies evaluating the relationship between focal and rotational activity and atrial cardiomyopathy are mandatory.

First clinical experience using a novel automated mapping algorithm for mapping of ventricular arrhythmias.

A new automated vector-based mapping algorithm (AMA) for 3-dimensional (3D) mapping has been introduced. The aim of this study was to present our experience using AMA to recognize additional catheter ablation targets in patients with ventricular arrhythmias (VA). A total of 16 patients (ICM; ischemic cardiomyopathy, n = 6; NICM; non-ischemic cardiomyopathy n = 10) suffering from VA underwent catheter ablation. Following bipolar voltage mapping, AMA was utilized to reveal zones of decelerated conduction velocity vectors (CVV) and this information was superimposed onto the 3D reconstructions and compared with the presence of scar. Mapping time was 28.1 ± 10 min for the endocardial reconstruction of the left ventricle (LV) and 17 ± 5.4 min for the epicardium (n = 6 patients). The mean area of LV low voltage was 13.9 ± 15% (endocardial) and 11.9 ± 5.7% (epicardial). Decelerating CVV zones were revealed in all patients (mean conduction velocity threshold of 39.3 ± 13%). Sustained VA have been terminated through ablation and substrate modification was performed in all patients. Correlation between the presence of CVV deceleration zones and areas of abnormal low voltage from bipolar mapping was revealed in only 37.5% of patients, but there was good correlation between scar from unipolar voltage mapping and the presence of CCV deceleration zones (94%; p = 0.008). The novel AMA may improve the understanding of individual VA substrates due to the visualization of decelerated CVV zones and their correlation with abnormal low voltage predominantly from unipolar mapping.

Direct comparison of two 50 W high power short duration approaches-Temperature- versus ablation index-guided radiofrequency ablation for atrial fibrillation.

INTRODUCTION: Approaches applying higher energy levels for shorter periods (high power short duration, HPSD) to improve lesion formation for atrial fibrillation (AF) ablation have been introduced. This single-center study aimed to compare the efficacy, safety, and lesion formation using the novel DiamondTemp (DT) catheter or an ablation index (AI)-guided HPSD ablation protocol using a force-sensing catheter with surround-flow irrigation. METHODS: One hundred thirteen consecutive patients undergoing radiofrequency-guided catheter ablation (RFCA) for AF were included. Forty-five patients treated with the DT catheter (50 W, 9 s), were compared to 68 consecutive patients undergoing AI-guided ablation (AI anterior 550; AI posterior 400) adherent to a 50 W HPSD protocol. Procedural data and AF recurrence were evaluated. RESULTS: Acute procedural success was achieved in all patients (n = 113, 100%). DT-guided AF ablation was associated with a longer mean procedure duration (99.10 ± 28.30 min vs. 78.24 ± 25.55, p < .001) and more RF applications (75.24 ± 30.76 min vs. 61.27 ± 14.06, p = .019). RF duration (792.13 ± 311.23 s vs. 1035.54 ± 287.24 s, p < .001) and fluoroscopy dose (183.81 ± 178.13 vs. 295.80 ± 247.54 yGym2 , p = .013) were lower in the DT group. AI-guided HPSD was associated with a higher AF-free survival rate without reaching statistical significance (p = .088). Especially patients with PERS AF (p = .009) as well as patients with additional atrial arrhythmia substrate (p = .002) benefited from an AI-guided ablation strategy. CONCLUSION: Temperature- and AI- controlled HPSD RFCA using 50 W was safe and effective. AI-guided HPSD ablation seems to be associated with shorter procedure durations and fewer RF applications. Particularly in advanced AF, freedom from AF-recurrence may be improved using an AI-guided HPSD approach.

AV-node isolation as an alternative to AV-node ablation in patients undergoing pace & ablate strategy.

INTRODUCTION: Atrioventricular (AV)-node ablation (AVNA) is a common therapy option for rate control strategy of permanent atrial fibrillation (AF). We hypothesized that isolation of the AV nodal isolation (AVNI) is associated with a more frequent preservation of an adequate escape rhythm compared to AVNA. METHODS: This retrospective study included 20 patients with therapy-refractory AF being treated with AVNI and 40 historical AVNA-controls. In AVNI the AV-node region was mapped using a 3D mapping system. Ablation was performed around the previously mapped HIS-cloud regions isolating the atrium from the AV-node. In the AVNI group, ablation was performed with irrigated tip ablation catheter in all cases. The two approaches were compared regarding rate of escape rhythm, delta QRS, and procedural data. RESULTS: The number of patients with adequate escape rhythm in AVNI was significantly superior to AVNA immediately postoperative (90% vs. 40%, p < 0.01) and during follow-up (77% vs. 36%, p < 0.05). The median change in QRS width was 0 ms in AVNI versus +26 ms in AVNA (p < 0.01). Thirty percent new bundle branch blocks in AVNA were observed compared to 0% in AVNI (p < 0.01). In the AVNI group, fluoroscopy time and total dose area product were significantly lower (p < 0.01). CONCLUSION: The present study suggests that AV-node isolation using 3D navigation mapping system is a feasible and effective alternative to conventional AVNA. The precise application of radiofrequency lesions preserves a stable AV-junctional rhythm.

A frozen decade: Ten years outcome of atrial fibrillation ablation using a single shot device for pulmonary vein isolation.

AIMS: Cryoballoon-guided pulmonary vein isolation (CB-PVI) for symptomatic atrial fibrillation (AF) has become an established treatment option with encouraging results in terms of safety and efficacy. Data reporting on long-term data beyond a follow-up (FU) period of 5 years is scarce. This prospective study aimed to evaluate very long-term outcome after CB-PVI for AF. METHODS: Data from consecutive patients treated with CB-PVI for symptomatic and drug refractory AF between 2005 and 2012 were analyzed. Patients with a FU of ≥9 years after index CB-PVI were included. All patients were continuously followed-up in our outpatient clinic. Arrhythmia recurrence was defined as AF or atrial tachycardia (AT) lasting >30 s beyond a 3-month blanking period. RESULTS: A total of 385 patients (71% male) were included. Mean age was 58 ± 10 years and paroxysmal AF was present in 93% of patients. Mean FU duration was 124 ± 24 months. At the end of the observational period, 73% of all patients were in stable sinus rhythm after a mean of 2 ± 0.8 ablation procedures. Patients with AF/AT recurrence were older (60 ± 8 vs. 57 ± 10 years; p = .019), had a higher CHA2 DS2 -Vasc Score (2.47 ± 1.46 vs. 1.98 ± 1.50; p = .01) and presented with a larger left atrium (LA)-diameter (43 ± 5.6 vs. 40 ± 5.1 mm; p = .002). The LA-diameter was also a significant predictor for AF/AT recurrence after CB-PVI (odds ratio: 0.939, 95% confidence interval: [0.886, 0.992], p = .03). CONCLUSIONS: CB-PVI as index procedure for AF ablation resulted in favorable long-term outcome in symptomatic AF. CB-PVI might be recommended as interventional therapy in patients with lower LA remodeling.

First clinical experience using a visualized sheath for atrial fibrillation ablation.

INTRODUCTION: Recently, a novel steerable sheath allowing its real-time visualization within a 3D-mapping system was introduced to facilitate atrial fibrillation (AF) ablation. AIM: This study aimed to assess safety and efficacy of AF ablation using the visualized sheath and to compare its performance with a matched control group of patients who received ablation with conventional and non-visualized sheaths. METHODS: The study included consecutive patients between 09/2019 and 02/2021 who underwent routine AF ablation using the visualized sheath. Patients were regularly followed-up in our outpatient's clinic. Arrhythmia recurrence was defined as any atrial fibrillation (AF)/ atrial tachycardia (AT) episode lasting > 30 s after a blanking period of 3 months. RESULTS: A total number of 100 patients undergoing ablation using the visualized sheath were compared to a group of 99 matched patients. No major complications were observed. Total procedure duration (108 ± 22 min vs. 112 ± 12 min; p = 0.045), fluoroscopy time (7 ± 3 min vs. 10 ± 5 min; p < 0.001) and -dose (507 ± 501 cGy*cm2 vs. 783 ± 433 cGy*cm2 ; p < 0.001) were significantly lower using the visualized sheath. The benefit in terms of procedure duration was mainly driven by a shortened left atrial dwell time (73 ± 13 min vs. 79 ± 12 min; p = 0.001). During a mean follow-up of 12 months, the overall procedural success was 85% in the visualized sheath group versus 83% in the control group (p = 0.948). CONCLUSION: AF ablation using the novel visualized sheath is safe and effective and leads to a measurable decrease of procedure duration and radiation exposure. The integration of the novel sheath might help to further improve safety and efficacy of AF ablation.

[Rhythm and metabolic control]. / Rhythmologische und metabolische Kontrolle.

Diabetes mellitus and atrial fibrillation show a steady increase in their prevalence. Diabetes mellitus is a relevant risk factor for the development and maintenance of atrial fibrillation, which should not be underestimated. Fluctuations in blood glucose levels occurring in diabetes, inflammatory processes and oxidative stress lead to structural, electromechanical, electrical and autonomic remodelling processes in the myocardium that promote atrial fibrillation. When atrial fibrillation and diabetes mellitus coincide, this is often associated with more pronounced symptoms, lower quality of life, more frequent hospitalization and a higher mortality rate. Can early and consistent euglycemic blood glucose monitoring effectively influence atrial remodelling processes, cardiovascular end points and the occurrence of atrial fibrillation? Are there new and combined drug treatment approaches for diabetes mellitus and atrial fibrillation? What ablation strategy should be adopted for the interventional treatment of atrial fibrillation in patients with diabetes mellitus? This review article attempts to find answers to these questions.

Mouse organic cation transporter 1 determines properties and regulation of basolateral organic cation transport in renal proximal tubules.

The proximal tubule of mouse kidney expresses mouse organic cation transporter 1 (mOCT1), mOCT2, and much less mOCT3. Therefore, mOCT-mediated transport across the basolateral membrane of proximal tubules reflects properties of at least mOCT1 and mOCT2. Here, we unraveled substrate affinities and modulation of transport activity by acute regulation by protein kinases on mOCT1 and mOCT2 separately and compared these findings with those from isolated proximal tubules of male and female mOCT2−/− mice. These data are also compared to our recent reports on isolated tubules from wild-type and mOCT1/2 double knockout (mOCT1/2−/−) mice. OCT-mediated transport in proximal tubules of mOCT2−/− mice was only 20 % lower compared to those isolated from wild-type mice. While mOCT1 was regulated by all five pathways examined [protein kinase A (PKA), protein kinase C (PKC), p56lck, phosphoinositide 3-kinase (PI3K), and calmodulin (CaM)], mOCT2 activity was modulated by PKA, p56lck, and CaM only, however, in the same direction. As mOCT-mediated transport across the basolateral membrane of mOCT2−/− mice expressing only mOCT1 and to a small amount mOCT3 was identical to that observed for tubules isolated from wild-type mice and to that observed for human embryonic kidney 293 (HEK293) cells stably expressing mOCT1, mOCT1 represents the relevant paralog for OCT-dependent organic cation transport in the mouse kidney. Gender does not play a major role in expression and activity of renal OCT-mediated transport in the mouse. Properties of mouse OCT considerably differ from those of rat or human origin, and thus, observations made in these rodents cannot directly be transferred to the human situation

Pressure waveform analysis for occlusion assessment significantly reduces contrast medium use in cryoballoon pulmonary vein isolation.

BACKGROUND: Pulmonary vein (PV) occlusion is crucial for adequate lesion formation during cryoballoon-guided pulmonary vein isolation (CB-PVI). PV occlusion is usually confirmed by angiographies over the inflated balloon device. The aim of our study was to analyze the safety and efficacy of pressure waveform-based PV occlusion assessment during CB-PVI utilizing a novel fully integrated pressure analysis tool. METHODS: Consecutive patients with symptomatic atrial fibrillation (AF) scheduled for CB-PVI were prospectively enrolled for pressure waveform-based PV occlusion assessment. A patient cohort receiving conventional angiographies served as control group. Patients with common PV ostia were excluded. RESULTS: The study group consisted of 40 patients (16 females, mean age was 64.5 ± 9.7, 45% persistent AF). The control group consisted of 40 matched patients. All 160 PVs in the study group were successfully isolated without the use of additional venograms confirming PV occlusion. The mean procedure duration was 69 ± 12 min in the study group with a mean fluoroscopy duration of 11.5 ± 4.4 min. The mean contrast medium volume was 22 ± 9 ml in the study group and 36 ± 12 ml in the control group (p = 0.0001). Mean procedure duration, mean balloon temperatures, and mean ablation application durations did not differ significantly between the study and the control group. No periprocedural complications occurred. CONCLUSION: CB-PVI utilizing a fully integrated pressure waveform analysis tool to assess PV occlusion is feasible and safe and significantly reduces the amount of contrast medium without impact on procedural parameters and freedom from arrhythmia recurrence.

Mortality after cardiac resynchronization therapy or right ventricular pacing in transcatheter aortic valve replacement recipients.

BACKGROUND: Permanent pacemaker implantation (PMI) is associated with increased morbidity after transcatheter aortic valve replacement (TAVR). Cardiac resynchronization-therapy (CRT) is recommended for patients if left ventricular ejection fraction (LVEF) is ≤ 40% and ventricular pacing is expected in favor to sole right ventricular (RV) pacing. Meanwhile, LVEF may recover after TAVR in patients with aortic valve disease and the benefit of CRT is unknown. OBJECTIVE: To analyze the impact of CRT implantation as compared to RV pacing after TAVR. METHODS AND RESULTS: Between 2012 and 2022, 4385 patients (53.1% female, mean age 81 ± 6 years) without prior PMI undergoing TAVR were retrospectively identified in our institutional registry. After stratification of patients in LVEF ≤ 40%, 41-49% and ≥ 50%, Kaplan-Meier analysis revealed significantly different survival rates in each subgroup at 5 years (37.0% vs. 43.5% vs. 55.1%; P ≤ 0.021). At multivariate regression, LVEF and new PMI after TAVR were not relevant for survival. A total of 105 patients with LVEF ≤ 40% received PMI after TAVR (86 patients with RV pacing and 19 with CRT). At 5 years, all-cause mortality was significantly lower in patients with CRT-device as compared to patients without CRT-device (Kaplan Meier estimate of 21.1% vs. 48.8%; HR 0.48, CI 0.204 - 1.128; log rank p = 0.045). In multivariate analysis CRT remained a significant factor for 5-year survival in these patients (HR 0.3, CI 0.095-0.951, p = 0.041). CONCLUSION: In patients undergoing TAVR, PMI did not influence 5-year survival. In patients with LVEF ≤ 40%, CRT-device implantation was associated with improved survival compared to non-CRT-device implantation.

Baroreflex activation therapy in advanced heart failure therapy: insights from a real-world scenario.

AIMS: Baroreflex activation therapy (BAT) is an innovative treatment option for advanced heart failure (HFrEF). We analysed patients' BAT acceptance and the outcome of BAT patients compared with HFrEF patients solely treated with a guideline-directed medical therapy (GDMT) and studied effects of sacubitril/valsartan (ARNI). METHODS: In this prospective study, 40 HFrEF patients (71 ± 3 years, 20% female) answered a questionnaire on the acceptance of BAT. Follow-up visits were performed after 3, 6, and 12 months. Primary efficacy endpoints included an improvement in QoL, NYHA class, LVEF, HF hospitalization, NT-proBNP levels, and 6MHWD. RESULTS: Twenty-nine patients (73%) showed interest in BAT. Ten patients (25%) opted for implantation. BAT and BAT + ARNI patients developed an increase in LVEF (BAT +10%, P-value (P) = 0.005*; BAT + ARNI +9%, P = 0.049*), an improved NYHA class (BAT -88%, P = 0.014*, BAT + ARNI -90%, P = 0.037*), QoL (BAT +21%, P = 0.020*, BAT + ARNI +22%, P = 0.012*), and reduced NT-proBNP levels (BAT -24%, P = 0.297, BAT + ARNI -37%, P = 0.297). BAT HF hospitalization rates were lower (50%) compared with control group patients (83%) (P = 0.020*). CONCLUSIONS: Although BAT has generated considerable interest, acceptance appears to be ambivalent. BAT improves outcome with regard to LVEF, NYHA class, QoL, NT-proBNP levels, and HF hospitalization rates. BAT + ARNI resulted in more pronounced effects than ARNI alone.

First clinical experience using the DiamondTemp catheter and a novel omnipolar high-resolution mapping system for atrial fibrillation ablation.

BACKGROUND: The DiamondTemp (DT) radiofrequency ablation (RFA) catheter has been introduced as a new tool for atrial fibrillation (AF) ablation. The new technology allows for temperature-controlled irrigated ablation and real-time lesion assessment. Recently, the EnSite X mapping system became commercially available allowing for omnipolar and ultra-high-resolution mapping. We aimed to assess the feasibility of the new DT RFA catheter in performing AF ablation procedures in conjunction with the novel EnSite X system under routine clinical conditions. METHODS: We analyzed data from 10 consecutive patients who underwent AF ablation using the DT RFA catheter guided by EnSite X. Procedural data and short-term follow-up were assessed as well as potential technical issues. RESULTS: Nine out of 10 patients underwent de-novo pulmonary vein isolation (PVI), and 1 patient underwent repeat ablation. First-pass isolation was observed in 7/10 patients. Total procedure duration (skin-to-skin) was 88.9 ± 30.1 min, and left atrium dwell time was 70 ± 22.3 min. The mean number of RF applications needed for PVI and additional ablation was 70.52 ± 26.70. The HD Grid SE mapping catheter was utilized in 8 patients and the Advisor SE in 2 patients. Bidirectional block of the applied lines was achieved in all patients. No steam pops were observed, and no intraprocedural complications occurred. CONCLUSIONS: This first clinical series demonstrated that temperature-controlled irrigated ablation in combination with the novel omnipolar and high-resolution mapping system resulted in rapid, efficient, and durable lesion formation under routine clinical conditions. Randomized controlled trials are needed to elucidate the impact on lesion formation, long-term outcomes, and reproducibility of our initial findings.

Challenges in the Implementation of Disruptive Innovations in Health Care Organizations.

Health organizations face barriers when seeking to deploy radical innovations, such as innovative telemonitoring approaches or AI based Clinical Decision Support Systems (CDSS) into their clinical workflow. However, these barriers are of various types and rarely known to organizations and their management. This study conducted a systematic literature review of 99 selected studies to identify the implementation barriers and factors encountered in this process. Using a hierarchical framework comprising of strategies, resources and capabilities, and processes, the study examined 16 barriers generated from the analysis of the individual studies. The findings highlight implementation barriers on all three levels of the proposed framework. By addressing these barriers comprehensively, health care organizations can successfully implement radical health innovations and enhance patient care outcomes and health care delivery.

Impact of pulmonary vein anatomy and ostial dimensions on long-term outcome after single-shot device-guided cryoablation for paroxysmal atrial fibrillation.

BACKGROUND: Cryoballoon (CB)-guided pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). This observational study aimed to assess the role of individual anatomical characteristics to predict long-term freedom from arrhythmia recurrence after CB-guided PVI for paroxysmal AF (PAF). METHODS: Three hundred fifty three consecutive patients (58 ± 11 years, 56% males), undergoing PVI between 2012 and 2018 were analysed. Individual pulmonary vein (PV) anatomy was assessed using preprocedural cardiac magnetic resonance imaging (MRI). For each PV, the cross-sectional area (CSA) was calculated. The impact of PV characteristics and CSA on long-term AF-free survival was evaluated. RESULTS: Acute PVI was achieved in all patients. Two hundred twenty-three patients (63%) had a normal PV anatomy (2 left- and 2 right-sided PV). Variant PV anatomy was present in 130 patients (37%). During the observation period of 48 months, AF-recurrence was documented in 167 patients (47 %). Patients with AF-recurrence presented with significantly enlarged right-sided PVs and left superior PVs (LSPVs) (p < 0.001). The presence of left common PVs (LCPVs) (n = 75, Log-rank p < 0.001) as well as right variant PVs (n = 35, Log rank p < 0.001) was associated with a significantly impaired long-term AF-free survival rate as compared to patients with normal PV characteristics. CONCLUSION: Variant PV anatomy is a good predictor for AF-recurrence. A correlation between an enlarged CSA of right-sided PVs as well as LSPVs and AF-recurrence was documented.

Regulation of organic cation transport in isolated mouse proximal tubules involves complex changes in protein trafficking and substrate affinity.

This study characterizes the complex mechanisms of acute regulation of organic cation (OC) transport across the basolateral membrane of isolated mouse proximal tubules. The fluorescent substrate ASP(+), 4-(-4-(dimethylamino) styryl-N-methylpyridinium, was used to quantify OC transport using a microtiter plate based fluorescence reader method. Inhibition of phosphatidylinositol-3-kinase, of p56 tyrosine kinase, stimulation of PKC and inhibition of PKA reduced ASP(+)-uptake. ASP(+)-kinetic and Dixon plot analyses revealed effects on transporter trafficking as explanation for the inhibition of ASP(+)-uptake by these pathways. Angiotensin II (AII) via stimulation of Ca(2+)/calmodulin increased ASP(+)-uptake. This effect aroused from an altered substrate affinity. Bafilomycin, an inhibitor of the vacuolar H(+)-ATPase and thus endosomal and lysosomal function, reduced ASP(+)-uptake, but did not prevent the AII effect on ASP(+)-uptake. Bafilomycin seemed to diminish the recycling rate of OCTs and hence to reduce the amount of transporters in the membrane. AII via Ca(2+)/calmodulin increased the substrate affinity of the remaining OCTs. The involvement of the cytoskeleton in acute regulation of OCTs became obvious as colchicine induced inhibition of microtubule polymerisation reduced ASP(+)-uptake. Acute regulation of mouse OCTs mostly involves changes in trafficking from and to the plasma membrane and only in the case of AII/CaM changes in substrate affinity.

When dystrophia meets ischaemia: a case report on cardiac involvement of myotonic dystrophy type 2 and successful arrhythmia elimination after catheter ablation.

BACKGROUND: This case reviews the cardiac involvement of myotonic dystrophy type 2 in terms of ventricular arrhythmias (VAs) and individual myocardial scar formation as target for catheter ablation. CASE SUMMARY: A 62-year-old woman with myotonic dystrophy type 2 and a severely reduced left ventricular ejection fraction (25%) presented with recurrent episodes of VAs and consecutive implantable cardioverter-defibrillator therapies. The patient already underwent two VA ablation attempts focusing on an ischaemia-related arrhythmia substrate in the left ventricle. The patient was scheduled for repeat ablation after the progression of coronary artery disease was ruled out. Interestingly bipolar voltage as well as activation mapping revealed an arrhythmia substrate along with the basal and inferior aspects of the right ventricle (RV). Catheter ablation of this scarred area in the RV resulted in specific termination of the VAs. Due to end-stage heart failure, key heart transplant criteria were met. The patient was evaluated for heart transplantation and added to the waiting list. Hitherto, no further VAs were documented during follow-up. DISCUSSION: As these patients present with specific dystrophia-related arrhythmia substrates, we propose pre-procedural visualization of dystrophy-associated arrhythmia substrates using cardiac magnetic resonance imaging allowing for personalized ablation approaches in these patients.