Catheter navigation by intracardiac echocardiography enables zero-fluoroscopy linear lesion formation and bidirectional cavotricuspid isthmus block in patients with typical atrial flutter.

INTRODUCTION: One of the most helpful aspects of intracardiac echocardiography (ICE) implementation in electrophysiological studies (EPS) is the real-time visualisation of catheters and cardiac structures. In this prospective study, we investigated ICE-guided zero-fluoroscopy catheter navigation during radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI) in patients with typical atrial flutter (AFL). METHODS AND RESULTS: Thirty consecutive patients (mean age 72.9 ± 11.4 years, 23 male) with ongoing (n = 23) or recent CTI-dependent AFL underwent an EPS, solely utilizing ICE for catheter navigation. Zero-fluoroscopy EPS could be successfully accomplished in all patients. Mean EPS duration was 41.4 ± 19.9 min, and mean ablation procedure duration was 20.8 ± 17.1 min. RF ablation was applied for 6.0 ± 3.1 min (50W, irrigated RF ablation). Echocardiographic parameters, such as CTI length, prominence of the Eustachian ridge (ER), and depth of the CTI pouch on the ablation plane, were assessed to analyse their correlation with EPS- or ablation procedure duration. The CTI pouch was shallower in patients with an ablation procedure duration above the median (4.8 ± 1.1 mm vs. 6.4 ± 0.9 mm, p = 0.04), suggesting a more lateral ablation plane in these patients, where the CTI musculature is stronger. CTI length or ER prominence above the respective median did not correlate with longer EPS duration. CONCLUSIONS: Zero-fluoroscopy CTI ablation guided solely by intracardiac echocardiography in patients with CTI-dependent AFL is feasible and safe. ICE visualisation may help to localise the optimal ablation plane, detect and correct poor tissue contact of the catheter tip, and recognise early potential complications during the ablation procedure.

Inhibition of Platelet Aggregation After Coronary Stenting in Patients Receiving Oral Anticoagulation.

BACKGROUND: Approximately 18% of patients with atrial fibrillation undergo a percutaneous coronary intervention (PCI) to treat coronary heart disease. Pharmacological anticoagulation in patients with atrial fibrillation and PCI involves a trade-off of potential ischemic and hemorrhagic complications. METHODS: This review is based on pertinent publications that were retrieved by a selective literature search, including current guidelines and recommendations. RESULTS: Dual antiplatelet therapy (DAPT) with acetylsalicylic acid (ASA) and a P2Y12 inhibitor protects against stent thrombosis, but not against thromboembolic stroke. In contrast, oral anticoagulation does provide effective prevention against stroke during atrial fibrillation. Combining DAPT with oral anticoagulation (triple therapy) over the long term, as has been recommended to date, carries an elevated risk of hemorrhage. In a randomized controlled trial, 44% of patients with atrial fibrillation receiving triple therapy sustained a hemorrhagic event, compared to 19.4% of patients receiving dual therapy. A meta-analysis has shown that clinically relevant hemorrhage is less common under combined treatment with one of the new oral anticoagulants (NOAC) and a single antiplatelet drug than under triple therapy including a vitamin K antagonist (hazard ratio, 0.56; 95% confidence interval 0.39; 0.80]), but no significant difference was found with respect to stent thrombosis, myocardial infarction, or overall mortality. CONCLUSION: After coronary stent implantation, dual therapy with a NOAC and a P2Y12 inhibitor is recommended, subsequent to triple therapy given only during the peri-interventional period.

Intracardiac echocardiography versus fluoroscopy for endovascular and endocardial catheter navigation during cryo-ablation of the slow pathway in AVNRT patients.

BACKGROUND: A new zero-fluoroscopy technique for electrophysiology catheter navigation relying on intracardiac echocardiography (ICE) has been recently reported (Ice&ICE trial). We investigated potential differences in efficacy, safety or procedural performance between conventional fluoroscopy- and ICE-guided cryothermal ablation (CA) in symptomatic AVNRT patients. METHODS: Clinical and electrophysiological data of AVNRT patients included in the Ice&ICE trial (22 patients, 16 females; =zero-fluoroscopy group) were compared to those of consecutive AVNRT patients, who underwent fluoroscopy-guided CA (25 patients, 17 females; = fluoroscopy group) during the last 2 years in our institution. RESULTS: Slow pathway ablation or modulation was successful in all patients. Fluoroscopy time and radiation dose in the fluoroscopy group were 11.2 ± 9.0 min and 20.3 ± 16.2Gycm2, whereas no fluoroscopy was used in the opposite group (p <  0.001, respectively). EPS duration was not different between the groups (zero-fluoroscopy:101.6 ± 40.2 min, fluoroscopy:99.4 ± 37.2 min, p = n.s.). Catheter placement time was significantly shorter in the fluoroscopy group (2.2 ± 1.6 min vs. 12.0 ± 7.5 min, p <  0.05), whereas cryo-application duration (from the first cryo-mapping to the last CA) was significantly shorter in the zero-fluoroscopy group (27.5 ± 37.0 min vs. 38.1 ± 33.9 min, p <  0.05). Mean cryo-mapping and CA applications were numerically lower in the zero-fluoroscopy group (CM:7.5 ± 5.7 vs. 8.8 ± 6.2; CA:3.1 ± 1.7 vs. 3.2 ± 2.0, p = n.s.). No major adverse events occurred in both groups. After 15.0 ± 4.2 months, arrhythmia recurrence was not different between the groups (4.5% vs. 8.0%, p = n.s.). CONCLUSIONS: Zero-fluoroscopy ICE-guided EP catheter navigation shows comparable efficacy and safety to fluoroscopic guidance during CA in AVNRT patients. ICE visualization of catheters and endocardial structures within the triangle of Koch shortens the cryo-application duration, though time needed for catheter placement is longer, when compared with conventional fluoroscopic guidance, which results in similar mean EPS duration with both navigation techniques. TRIAL REGISTRATION: (German Clinical Trials Register ID: DRKS00011360 ; Registration Date 14.12.2016).

Cerebrovascular events, bleeding complications and device related thrombi in atrial fibrillation patients with chronic kidney disease and left atrial appendage closure with the WATCHMAN™ device.

BACKGROUND: Impaired renal function increases the bleeding risk, leading to a conservative prescription and frequent discontinuation of oral anticoagulation in atrial fibrillation patients with chronic kidney disease (CKD). Interventional left atrial appendage closure (LAAC) might be an alternative therapeutic strategy for these patients. METHODS: We aimed to prospectively assess cerebrovascular (CE) and bleeding events, as well as peri-procedural and long-term complications in a cohort of consecutive patients undergoing interventional LAAC using the WATCHMAN™ device, with focus on CKD patients. RESULTS: One hundred and eighty-nine consecutive patients undergoing interventional LAAC were included in this analysis; 171 (90.5%) patients had a reduced estimated glomerular filtration rate (eGFR; patients for each CKD stage: II = 66; IIIa = 32; IIIb = 43; IV = 18; V = 12). During a follow-up of 310 patient years three (1.0%) patients suffered a CE (two strokes, one transitory ischemic attack) and five (1.6%) other ones a bleeding complication. The observed stroke rate was more than two-thirds and the bleeding risk more than half lower than expected. Device related thrombi (DRT) were detected in twelve (6.5%) patients; women had significantly more DRT than men (12.5% vs. 2.6%; p = 0.009). Patients with an eGFR< 30 ml/min/1.73m2 showed a trend to a higher DRT rate as compared to the opposite group (13.3% vs. 5.1%; p = 0.10). Thrombus resolved with temporary oral anticoagulation therapy in ten patients without sequelae; thrombus consolidation was confirmed by serial TEE controls in the remaining two patients. CONCLUSIONS: Atrial fibrillation patients with CKD have low CE and bleeding rates after LAAC with the WATCHMAN™ device. DRT risk is higher in female and patients with severe CKD. More frequent post-interventional TEE controls might be justified for early DRT detection and safe management of patients at high DRT risk. TRIAL REGISTRATION: (German Clinical Trials Register ID: DRKS00 010768 ; Registration Date 07.07.2016).

Impact of internal and external electrical cardioversion on cardiac specific enzymes and inflammation in patients with atrial fibrillation and heart failure.

BACKGROUND: Implantable cardioverter/defibrillator (ICD) shocks can cause myocardial injury, contributing to the progression of the underlying heart disease. The aim was to evaluate whether internal electrical cardioversion (int-CV) via the ICD or conventional external CV (ext-CV) of persistent atrial fibrillation (AF) in heart failure (HF) patients induces myocardial injury and initiates inflammation. METHODS AND RESULTS: A total of 115 HF patients with an ejection fraction between 20% and 45% were prospectively enrolled. Fifty-one patients were excluded due to failure of electrical CV at the first attempt as well as early relapse of AF within 8h after CV. The int-CV group consisted of 22 and the ext-CV group of 42 patients. Baseline values of high sensitive troponin T (hsTnT), interleukin (IL)-6, and C-reactive protein (CRP) did not differ significantly in both groups, whereas baseline N-terminal pro B-type natriuretic peptide (NT-pro BNP) was significantly lower in the ext-CV group. Eight hours after CV, the level of hsTnT increased significantly in the int-CV group, whereas no significant change was observed in the ext-CV group. Furthermore, CV significantly increased IL-6 and CRP in the int-CV group, whereas an insignificant increase could be documented in the ext-CV group. Due to electrical CV in both groups, the NT-pro BNP levels significantly declined in approximately the same content (int-CV 29% vs. ext-CV 36%). CONCLUSIONS: The significant increase in hsTnT, IL-6, and CRP in patients who underwent int-CV compared to those undergoing ext-CV may suggest that int-CV causes significant myocardial damage and induces systemic inflammation.

Zero-fluoroscopy cryothermal ablation of atrioventricular nodal re-entry tachycardia guided by endovascular and endocardial catheter visualization using intracardiac echocardiography (Ice&ICE Trial).

INTRODUCTION: Stochastic damage of the ionizing radiation to both patients and medical staff is a drawback of fluoroscopic guidance during catheter ablation of cardiac arrhythmias. Therefore, emerging zero-fluoroscopy catheter-guidance techniques are of great interest. METHODS AND RESULTS: We investigated, in a prospective pilot study, the feasibility and safety of the cryothermal (CA) slow-pathway ablation in patients with symptomatic atrioventricular-nodal-re-entry-tachycardia (AVNRT) using solely intracardiac echocardiography (ICE) for endovascular and endocardial catheter visualization. Twenty-five consecutive patients (mean age 55.6 ± 12.0 years, 17 female) with ECG-documentation or symptoms suggesting AVNRT underwent an electrophysiology study (EPS) in our laboratory utilizing ICE for catheter navigation. Supraventricular tachycardia was inducible in 23 (92%) patients; AVNRT was confirmed by appropriate stimulation maneuvers in 20 (80%) patients. All EPS in the AVNRT subgroup could be accomplished without need for fluoroscopy, relying solely on ICE-guidance. CA guided by anatomical location and slow-pathway potentials was successful in all patients, median cryo-mappings = 6 (IQR:3-10), median cryo-ablations = 2 (IQR:1-3). Fluoroscopy was used to facilitate the trans-septal puncture and localization of the ablation substrate in the remaining 3 patients (one focal atrial tachycardia and two atrioventricular-re-entry-tachycardias). Mean EPS duration in the AVNRT subgroup was 99.8 ± 39.6 minutes, ICE guided catheter placement 11.9 ± 5.8 minutes, time needed for diagnostic evaluation 27.1 ± 10.8 minutes, and cryo-application duration 26.3 ± 30.8 minutes. CONCLUSIONS: ICE-guided zero-fluoroscopy CA in AVNRT patients is feasible and safe. Real-time visualization of the true endovascular borders and cardiac structures allow for safe catheter navigation during the ICE-guided EPS and might be an alternative to visualization technologies using geometry reconstructions.

Left atrial enlargement and clinical considerations in patients with or without a residual interatrial shunt after closure of the left atrial appendage with the WATCHMAN™-device.

BACKGROUND: Interventional closure of the left atrial appendage (LAA) in patients with non-valvular atrial fibrillation, high thromboembolic and bleeding risk or bleeding history is an alternative therapeutic strategy to oral anticoagulation. It is not known if the exclusion of the LAA from the blood circulation affects the left atrial volume (LAV) and consequently its prognostic value or the circulatory performance of the heart in humans. METHODS: We aimed to prospectively assess potential changes in baseline LAV, left ventricular ejection fraction (LVEF), NT-proBNP-level and the covered distance in the 6-min walk-test 6 weeks and 6 months after LAA closure with the WATCHMAN™ device. We used serial 3-dimensional transthoracic and transesophageal echocardiography to assess LAV, residual interatrial shunt and device performance in 58 consecutive patients with successful LAA closure. RESULTS: Accurate 3D-echocardiographic data for LAV measurements were evaluable for 51 (91%) patients. Maximum LAV (LAVmax) at baseline was 102.8 ± 30.8 ml and increased significantly to 107.7 ± 32.8 ml after 6 weeks (p < 0.01) and 113.5 ± 34.2 ml after 6 months (p < 0.01). Minimal LAV (LAVmin) increased from 76.9 ± 29.5 ml at baseline to 81.8 ± 30.2 ml after 45 days (p < 0.01) and 82.1 ± 33.3 ml after 6 months (p < 0.01). Similarly, their indexes to BSA (LAVImax and LAVImin) increased significantly, as well. Patients without a residual left-to-right interatrial shunt showed a significantly higher increase in LAVmax or LAVmin. Baseline LVEF, NT-proBNP-level or the distance covered at the 6-min walk test did not significantly change 6 weeks or 6 months after LAA closure. CONCLUSIONS: LAVmax and LAVmin increase significantly after interventional LAA closure. LA enlargement does not correlate with clinical progression of heart failure. Persistent left-to-right interatrial shunt counteracts the LA enlargement. A reduced LA compliance after exclusion of the LAA from the blood circulation with consecutive increase in LA pressure may be a potential cause of LA enlargement and warrants further investigation. TRIAL REGISTRATION: German Clinical Trials Register ID: DRKS00010768 ; Registration Date 07.07.2016.

Takotsubo Cardiomyopathy: What we have Learned in the Last 25 Years? (A Comparative Literature Review).

We performed a comparative literature review, to elucidate the major features of the Takotsubo (stress) cardiomyopathy (TCM) collected in last 25 years. TCM is characterized by left- or biventricular apical ballooning with a clinical presentation, electrocardiographic abnormalities, and biomarker profils similar to those seen in acute myocardial infarction. Epidemiological studies have shown that TCM is more common in postmenopausal women; however exact figures are not available. The underlying aetiology is still largely undetermined. Elevated catecholamine levels, lack of estrogen, disturbed myocardial fatty acid metabolism and plaque rupture with spontaneous thrombolysis are potentially discussed mechanisms responsible for inducing a prolonged stunned myocardium. Strong emotional or physical stress is the most frequently described trigger in the literature. Therapy recommendations include appropriate antiplatelet treatment, ß-blockers and ACE inhibitors. The abnormal kinetics usually resolve or improve within a month and carry a favorable prognosis in most cases. However, all the suspected complications of an acute myocardial infarction, including cardiogenic shock or lethal arrhythmias, may still occur.

Marked prolongation of QRS duration after initiation of dronedarone therapy.

Dronedarone is a relatively new antiarrhythmic drug and is held to be less proarrhythmic than comparable compounds, although its proarrhythmia potential in humans has not been sufficiently evaluated. We describe a so far unreported dronedarone effect, namely a significant alteration of both the morphology and the duration of the QRS complex on the electro cardiogram in a 41-year old patient with symptomatic paroxysmal atrial fibrillation.

Which patient is most likely to benefit from dronedarone? Analysis from the Magdeburg Dronedarone Registry (MADRE study).

Based on an analysis of the Magdeburg Dronedarone Registry data we sought to determine which patients could benefit from dronedarone therapy regarding rhythm control. The study included 191 patients (85 women) aged 63 ± 10 years with a history of paroxysmal or persistent AF and a follow-up of 14 ± 5 months. The total AF recurrence rate was 67% and lone AF was significantly more often associated with AF recurrences than non-lone AF (84% vs. 62%, P = .01). Arterial hypertension, treated coronary artery disease, and diabetes mellitus were not significantly related to AF recurrences (64%, 67%, 58% resp. P = .3). Response rate to dronedarone in patients with slightly increased left atrial size was significantly greater than in patients with normal or markedly increased left atrial size (47%, 16%, 27% resp., P = .001). The rate of adverse effects was 32% in the study sample, and was significantly lower in patients with lone AF as compared to those with non-lone AF (11% vs. 37%, P = .002). The body mass index was a predictor neither of response rate nor adverse effects. The results suggest that dronedarone is more effective in patients with non-lone AF and slightly increased left atrial size.

Efficacy and safety profile of dronedarone in clinical practice. Results of the Magdeburg Dronedarone Registry (MADRE study).

BACKGROUND: Dronedarone is a new antiarrhythmic agent that has only recently been approved for the therapy of atrial fibrillation (AF). Results regarding a broader spectrum of patients and experience accumulated in clinical practice are still very scarce. Therefore, we prospectively investigated the efficacy and tolerance of dronedarone in a real life setting. METHODS AND RESULTS: The study included 191 patients (85 women) aged 63 ± 9.9 years with a history of paroxysmal or persistent AF. Follow-up time was 14.3 ± 4.9 months. In patients with persistent AF, sinus rhythm was restored using electrical cardioversion prior to dronedarone administration. Each patient underwent standard ECG on a daily basis during the first 4 days of treatment, and on days 7, 30 and 90, resp. After that, the patients had a follow-up visit every three months. Creatinine, creatine kinase, and hepatic enzymes were closely monitored. Clinical history was meticulously taken at multiple follow-up visits. Dronedarone maintained sinus rhythm in 33.5% (95% CI: 27%-40%), and AF recurrence rate was high: 66.5% (95% CI: 60%-73%). Adverse effects occurred in 31.9% (95% CI: 27%-38%) of the patients and necessitated permanent discontinuation of dronedarone in 22% (95% CI: 17%-27%). CONCLUSIONS: The results suggest that dronedarone may not be superior to available antiarrhythmic agents and caution against its use as a first line therapy in AF.

Intra-atrial endothelial lesion resulting from transseptal puncture for catheter ablation of atrial fibrillation.

Thromboembolic events are known complications of left atrial ablation therapy. We describe a complication which may also lead to systemic thromboembolism that has not been reported so far: the formation of a moving structure attached to the fossa ovalis after an attempted transseptal puncture in a 66-year old patient with symptomatic paroxysmal atrial fibrillation.