First data on cardiac mapping and outcome of pulmonary vein isolation using a novel ablation catheter with tip mini electrodes.

AIMS: Pulmonary vein isolation (PVI) is a standard treatment of atrial fibrillation (AF). AF recurrence after PVI occurs in a substantial number of cases. A novel ablation catheter equipped with mini-electrodes (ME) may facilitate PVI. Our study evaluated outcome after PVI with the ME catheter compared to a standard catheter. METHODS: Patients undergoing PVI with the ME catheter were compared to a control group ablated with a standard contact force sensing catheter. Freedom of AF after 12 months was the study endpoint. Additionally, low voltage areas (LVA) <0.5 mV were identified with a circular mapping catheter (CMC) and the ablation catheter in each group. LVA were compared between the maps obtained with the CMC and the ME or standard catheter, respectively. RESULTS: A total of 110 patients underwent PVI with ME catheter (n = 59) or the standard catheter (n = 51). Procedure duration (117.4 ±â€¯43 vs. 103.1 ±â€¯32.8 min, p = 0.15), radiation dose (1135.6 ±â€¯1125.7 vs. 1078.8 ±â€¯951.4 µGy/m2, p = 0.91), incidence of complications and 12-month success rate (64.4 vs 72.5%, p = 0.36) were not significantly different between the groups. LVA were significantly smaller when obtained with the standard catheter compared to the CMC (14 ±â€¯13 vs. 58.5 ±â€¯22.1 cm2, p < 0.001), while no such difference was seen for mapping with the ME compared to the CMC (37 ±â€¯30.3 vs. 33.4 ±â€¯39 cm2, p = 0.4). CONCLUSION: Clinical outcomes are comparable between ME catheter and a standard contact force sensing catheter. Furthermore, better LVA detection points to improved mapping capabilities of the ME catheter.

[Radiation reduction in interventional electrophysiology : Results from operators with different levels of experience]. / Strahlenreduktion in der interventionellen Elektrophysiologie : Verlaufsdaten bei Untersuchern mit unterschiedlicher Erfahrung.

BACKGROUND: Radiation exposure in the catherization laboratory is associated with significant health risks. It is unclear whether a reduction of radiation exposure with the use of "near-zero fluoroscopy" protocols is possible when applied by less experienced operators. METHODS: Consecutive ablation procedures with the use of a 3D mapping system were analyzed. Three time periods were analyzed. During the first period (standard), no specific radiation-reduction protocol was used. During the second period (initial phase of radiation reduction) a near "near-zero fluoroscopy" protocol was implemented; however, the majority of procedures were performed by an expert. During the third period (routine use of radiation reduction), less experienced operators (fellow and beginner) performed a growing number of procedures with the "near-zero fluoroscopy" protocol. RESULTS: In all, 290 procedures were analyzed. After implementation of a radiation-reduced protocol, a significant reduction of radiation exposure was observed (standard 850 ± 831.7 vs. initial phase 197.2 ± 481.8 µGy/m2, p < 0.001, and vs. routine use 283 ± 493.8 µGy/m2, p < 0.001). No significant difference was observed between the initial phase and routine phase (p = 1). Over the three periods, the proportion of procedures performed by less experienced operators grew significantly for complex (fellow: 0% vs. 10% vs. 30%; p < 0.001) and noncomplex procedures (fellow: 30% vs. 39% vs. 49%; beginner: 15% vs. 38% vs. 34%; p = 0.002). Complication rates were not significantly different. CONCLUSIONS: Implementation of a radiation-reduced protocol leads to a significant reduction of radiation exposure even in less experienced operators during training.

Implementation of a near-zero fluoroscopy approach in interventional electrophysiology: impact of operator experience.

PURPOSE: Catheter ablation is performed under fluoroscopic guidance. Reduction of radiation dose for patients and staff is emphasized by current recommendations. Previous studies have shown that lower operator experience leads to increased radiation dose. On the other hand, less experienced operators may depend even more on fluoroscopic guidance. Our study aimed to evaluate feasibility and efficacy of a non-fluoroscopic approach in different training levels. METHODS: From January 2017, a near-zero fluoroscopy approach was established in two centers. Four operators (beginner, 1st year fellow, 2nd year fellow, expert) were instructed to perform the complete procedure with the use of a 3-D mapping system without fluoroscopy. A historical cohort that underwent procedures with fluoroscopy use served as control group. Dose area product (DPA), procedure duration, acute procedural success, and complications were compared between the groups and for each operator. RESULTS: Procedures were performed in 157 patients. The first 100 patients underwent procedures with fluoroscopic guidance, the following 57 procedures were performed with the near-zero fluoroscopy approach. The results show a significant reduction in DPA for all operators immediately after implementation of the near-zero fluoroscopy protocol (control 637 ± 611 µGy/m2; beginner 44.1 ± 79.5 µGy/m2, p = 0.002; 1st year fellow 24.3 ± 46.4.5 µGy/m2, p = 0.001; 2nd year fellow 130.3 ± 233.3 µGy/m2, p = 0.003; expert 9.3 ± 37.4 µGy/m2, P < 0.001). Procedure duration, acute success, and complications were not significantly different between the groups. CONCLUSION: Our results show a 90% reduction of DPA shortly after implementation of a near-zero fluoroscopy approach in interventional electrophysiology even in operators in training.

Effects of propofol on ventricular repolarization and incidence of malignant arrhythmias in adults.

BACKGROUND: Propofol is commonly used for procedural sedation in interventional electrophysiology. However, ventricular arrhythmias under Propofol have been reported. Our aim was to investigate ventricular repolarization and incidence of ventricular arrhythmias under Propofol infusion in adults with cardiac arrhythmias. METHODS: QRS, QTcB (Bazett), QTcFri (Fridericia), JTc, measurement of T peak to Tend time (Tp-e) at baseline and under Propofol infusion was performed in 235 patients. Screening for unexpected ventricular arrhythmias was performed in 1165 patients undergoing EP procedures under Propofol. RESULTS: A significant prolongation of Tp-e under Propofol infusion (79.7±17.3 vs. 86.4±22.5ms, p<0.001) and of QTcFri (429.3±35.8 vs. 435.5±36.5, p=0.033) was detected. No significant change of the QTcB interval, JTc interval or QRS duration was observed. One case (0.09%) of ventricular fibrillation during rapid ventricular pacing under Propofol occurred. CONCLUSION: Although transmural dispersion of ventricular repolarisation is increased under Propofol, incidence of malignant ventricular arrhythmias is low. For evaluation of QT interval under Propofol, Fridericia's correction formula should be used rather than Bazett's formula.

Cardiac mapping and pulmonary vein isolation using a novel ablation catheter with tip minielectrodes.

BACKGROUND: Pulmonary vein isolation (PVI) is a standard treatment for atrial fibrillation (AF). Identification of gaps in the ablation line is difficult. Tip-ring electrograms from ablation catheters represent relative large areas of myocardial tissue. Recently, an ablation catheter with three minielectrodes (ME) on the catheter tip with closer interelectrode spacing was introduced. The aim of our study was to evaluate the novel electrodes during PVI. METHODS: PVI was performed with an irrigated ablation catheter equipped with conventional electrodes and three additional radial tip electrodes. Detection of pulmonary vein potentials (PVPs), local signal amplitude, amplitude reduction during ablation, and loss of capture after ablation were compared between the ME and the conventional tip-ring electrodes. RESULTS: Thirty-one patients (mean age 67.8 ± 10.3 years, 45.2 % men) were included. A total of 306 mapping/lesion points were analyzed. A PVP was significantly more often obtained with the ME compared to the conventional tip-ring electrodes (99.2% vs 83.5%, P < 0.001). Local amplitude was significantly higher on the ME (0.8 ± 0.6 mV vs 0.67 ± 0.46 mV, P  =  0.003). Amplitude reduction during 1 RF pulse was significantly greater on the ME (82.9 ± 19.5% vs. 61.8 ± 26.9%, P < 0.001). During pace mapping, loss of capture after 1 RF pulse was observed significantly more often on ME (98.3% vs 63.3%, P < 0.001). CONCLUSION: Signal amplitude is higher and sensitivity during PVP mapping and ablation is increased when ME are used. ME may facilitate catheter ablation of AF in the future.

Use of a Patient-Activated Event Recording System in Patients with Tachycardic Palpitations: How Long to Follow Up?

INTRODUCTION: Palpitations are a common symptom causing patients to consult a cardiologist, yet diagnosing a potential cardiac origin can be difficult. In patients with a nondiagnostic Holter-ECG, external loop-recorders are an additional tool to diagnose the clinical arrhythmia in these patients. The aim of our study was to evaluate the additional value of an external, patient-activated loop recorder and to determine the optimal time of follow up needed to achieve a symptom-rhythm correlation with the device. METHODS AND RESULTS: A total of 1404 patients presented to our outpatient clinic between November 2011 and November 2014 for first time evaluation of symptomatic arrhythmias. Of a total of 91 patients were included (age 43.6±18.1; 69.2% female) in the study. All patients presented with tachycardic palpitations and a 48-hour Holter-ECG that did not detect relevant arrhythmias. All patients were given a "leadless" patient-activated event-recording system and regular follow-up visits were scheduled after 3, 6, and 12 months. Within a maximum follow-up time of 1 year, 72 patients (79.1%) recorded at least one ECG with the device. Of the recorded ECGs, 51% were recorded within the first week after the device was handed out. This figure rises to 80% and 93% after 1 and 2 months. The last recording was after 174 days. CONCLUSION: For patients with tachycardic palpitations, the external "leadess" event recorders are effective in achieving a symptom-rhythm correlation. A follow up of 2 months will suffice to establish a diagnosis in a large majority of this patient group.

Performance of chest compressions with the use of a new audio-visual feedback device: a randomized manikin study in health care professionals.

AIM: Optimal depth (50-60mm) and rate (100-120min(-1)) of chest compressions (CC) is the prerequisite of effective cardiopulmonary resuscitation (CPR). However, insufficient CC during CPR are common even among health care professionals. We sought to evaluate if CC are more effective with the use of a novel feedback device compared to standard CC. Primary endpoints were absolute percentage of correct CC of all CC (correct rate and correct depth, classified as "optimal" CC), and the percentage of CC in target rate and percentage of CC in target depth. METHODS: 63 healthcare professionals performed CC on a manikin with the use of a novel feedback device. The device provides audio-visual information about compression depth and rate. Each participant performed two minutes of CC with and without feedback. Participants were randomized into two groups that performed either CC with feedback first, followed by a trial without feedback, or vice versa. All participants answered a short questionnaire on self-estimation of CC performance. RESULTS: The absolute percentage of optimal compressions of all compressions has increased from 27.9±28.8% to 47.6±33.5% (p<0.001) with use of the device. Furthermore, a significant increase of the percentage of CC in target depth (35.9±30.6% without vs. 54.8±33.5% with the device, p=0.003) and in target rate (70.5±37.7% without vs. 82.7±27.8 with the device, p=0.039) were observed. CONCLUSION: This novel feedback device significantly improved the quality of CC in health care professionals.

Minimal and deep sedation during ablation of ventricular tachycardia.

BACKGROUND: Catheter ablation is a curative treatment option for ventricular premature contractions (VPC) and ventricular tachycardia (VT). Procedures require different sedation levels, depending on duration, ablation approach and patient characteristics. The aim of our study was to evaluate feasibility of minimal and deep sedation for ablation of VPC/VT. METHODS: Patients underwent catheter ablation of VPC/VT under minimal or deep sedation. Events of hypotension, hypoxia, bradycardia, procedural complications and VT inducibility were compared between the groups. RESULTS: 120 patients were included. In 42 patients (53.6 ± 17.1 years, 47.6% male) ablation was performed under minimal sedation with midazolam, and in 78 patients (54.2 ± 17.5 years, 67.9% male) ablation was performed under deep sedation with propofol/midazolam. There were significantly fewer patients with idiopathic VT (62.8 vs. 88.1%, p=0.011) in the deep sedation group, LVEF was significantly lower (47 ± 14.4 vs. 53.1 ± 11.7) and the procedure duration was significantly longer (201.9 ± 85.9 vs. 137.9 ± 98.7). No significant differences in procedural complications or sedation related events (hypotension: 0 vs. 3.8%, p=0.2, no hypoxia, no bradycardia) were detected. CONCLUSIONS: Minimal sedation and deep sedation are both feasible during VPC/VT ablation procedures. Propofol does not increase complications even in a collective with pre-existing impairment of LVEF. Adequate monitoring and trained personnel should be present.

Deep sedation during catheter ablation for atrial fibrillation in elderly patients.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia. AF incidence increases with age. AF ablation procedures are routinely performed under deep sedation with propofol. The purpose of the study was to evaluate if propofol deep sedation during AF ablation is safe in elderly patients. METHODS: Four hundred one consecutive patients (mean age, 61.4 ± 11.1 years; range, 20-82; 66.3 % men) who were presented to our institution for ablation of symptomatic AF were enrolled. Patients were divided into three groups: Patients in group A were ≤50 years old; patients in group B were 51-74 years old; and patients in group C were ≥75 years old. Procedures were performed under deep sedation with propofol, midazolam, and piritramide. SaO2, electrocardiogram, arterial blood pressure, and arterial blood gas were monitored throughout the procedure. Sedation-related complications, intraprocedural complications, and other adverse events were evaluated. Fisher exact or χ (2) tests were used for comparison of adverse events and complications among groups. Analysis of variance was used to compare sedation- and procedure-related parameters. RESULTS: Fifty-three (13.2 %) elderly patients were in group C and were compared to 73 (18.2 %) patients in group A and 275 (68.8 %) in group B. No significant differences in sedation-related or intraprocedural complications were seen (group A, 1.4 %; group B, 1.1 %; group C, 3.7 %; p = 0.336). Despite a significantly greater drop in systolic blood pressure in under sedation in group C (group A, 15.5 ± 9.5 mmHg; group B, 18.9 ± 16.3 mmHg; group C, 32.3 ± 15.5 mmHg; p < 0.001), no prolonged hypotension was observed. The rate of other adverse events (delirium, respiratory infection, renal failure) was significantly higher in group C (9.4 %), compared to group A (0 %) and group B (2.2 %; p = 0.004). CONCLUSION: Deep sedation with propofol and midazolam during AF ablation did not result in an increased rate in sedation-related complications in elderly patients. Similarly, the rate of procedural complications was not significantly different among the study groups. The rate of respiratory infections and renal failure was significantly higher in the elderly. All adverse events were treated successfully without any remaining sequelae.

Variations in the human soluble epoxide hydrolase gene and recurrence of atrial fibrillation after catheter ablation.

BACKGROUND: Single nucleotide polymorphisms (SNPs) of EPHX2 alter sEH activity and are associated with increased [rs41507953 (K55R)] or reduced [rs751141 (R287Q)] cardiovascular risk via modulation of fibrosis, inflammation or cardiac ion channels. This indicates an effect on development and therapy response of AF. This study tested the hypothesis that variations in the EPHX2 gene encoding human soluble epoxide hydrolase (sEH) are associated with atrial fibrillation (AF) and recurrence of atrial fibrillation after catheter ablation. METHODS AND RESULTS: A total of 218 consecutive patients who underwent catheter ablation for drug refractory AF and 268 controls were included. Two SNPs, rs41507953 and rs751141, were genotyped by direct sequencing. In the ablation group, holter recordings 3, 12 and 24 months after ablation were used to detect AF recurrence. No significant association of the SNPs and AF at baseline was detected. In the ablation group, recurrence of AF occurred in 20% of the patients 12 months after ablation and in 35% 24 months after ablation. The presence of the rs751141 polymorphism significantly increased the risk of AF recurrence 12 months (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.237 to 8.276, p=0.016) and 24 months (OR: 6.076, 95% CI: 2.244 to 16.451, p<0.0001) after catheter ablation. CONCLUSIONS: The presence of rs751141 polymorphism is associated with a significantly increased risk of AF recurrence after catheter ablation. These results point to stratification of catheter ablation by genotype and differential use of sEH-inhibitory drugs in the future.