Project description:A 42-year-old man was admitted for recurrent atrioventricular reciprocating tachycardia. We performed a total activation mapping, which included a range from the ventricular to atrial waves during right ventricular pacing. The mapping revealed a delayed ventriculoatrial conduction on the left lateral wall. We performed ablation within the coronary sinus, and the ventriculoatrial conduction was lost. By widening the range, we could easily visualize the ventriculoatrial conduction through the accessory pathway. This mapping showed that the conduction in the area of the accessory pathway was delayed, and it was easy to estimate that the conduction pathway included the coronary sinus.
Project description:AimsLinear lesions are routinely created by radiofrequency catheter ablation. Unwanted electrical conduction gaps can be produced and are often difficult to ablate. This study aimed to clarify the characteristics of conduction gaps during atrial fibrillation ablation by analysing bidirectional activation maps using a high-density mapping system (RHYTHMIA).Methods and resultsThis retrospective study included 31 patients who had conduction gaps along pulmonary vein (PV) isolation or box ablation lesions. Activation maps were sequentially created during pacing from the coronary sinus and PV to reveal the earliest activation site, defined by the entrance and exit. The locations, length between the entrance and exit (gap length), and direction were analysed. Thirty-four bidirectional activation maps were drawn: 21 were box isolation lesions (box group), and 13 were PV isolation lesions (PVI group). Among the box group, nine conduction gaps were present in the roof region and 12 in the bottom region, while nine in right PV and four in left PV among the PVI group. Gap lengths in the roof region were longer than those in the bottom region (26.8 ± 11.8 vs. 14.5 ± 9.8 mm; P = 0.022), while those in right PV tended to longer than those in left PV (28.0 ± 15.3 vs. 16.8 ± 8.0 mm, P = 0.201).ConclusionThe entrances and exits of electrical conduction gaps were separated, especially in the roof region, indicating that epicardial conduction might contribute to gap formation. Identifying the bidirectional conduction gap might indicate the location and direction of epicardial conduction.
Project description:Radiofrequency catheter ablation (RFCA) is the primary choice for treating patients with an accessory pathway and atrioventricular re-entrant tachycardia. However, using RFCA to treat a right-sided accessory pathway in a patient with Ebstein anomaly can be difficult owing to challenges in locating the electrophysiological atrioventricular groove. We report a case of atrioventricular re-entrant tachycardia in a patient with Ebstein anomaly and a right-sided accessory pathway that was successfully treated using RFCA and 3-dimensional (3D) high-density mapping. RFCA and 3D mapping may be useful in the management of such cases and may aid in improving prognoses of patients.
Project description:Proper localization of the anatomical target during ablation of the accessory pathways (AP) and the ability to detect clear AP potentials on the ablation catheter are crucial for successful AP ablation. We report a case of recurring AP conduction that was finally eliminated using a novel ablation catheter equipped with high-resolution mini-electrodes. Smaller and closer electrodes result in high mapping resolution with less signal averaging and cancellation effects. Owing to improved sensitivity, the new catheter seems effective in detecting fragmented and high frequency signals, thus allowing more effective radiofrequency application and improving ablation success.
Project description:PurposeThe purpose of this study was to evaluate ultra high density-activation sequence mapping (UHD-ASM) for ablating atypical atrial flutters.MethodsFor 23 patients with 31 atypical atrial flutters (AAF), we created UHD-ASM.ResultsDemographics age = 65.3 ± 8.5 years, male = 78%, left atrial size = 4.66 ± 0.64 cm, redo ablation 20/23(87%). AAF were left atrial in 30 (97%). For each AAF, 1273 ± 697 points were used for UHD-ASM. Time to create and interpret the UHD-ASM was 20 ± 11 min. For every AAF, the entire circuit was identified. Thirty (97%) were macroreentry. AAF cycle length was 267 ± 49 ms, and the circuit length was 138 ± 38 mm (range 35-187). Macroreentry atrial flutters took varied pathways, but each had an area of slow conduction (ASC) averaging 16 ± 6 mm (range 6-29) in length. Entrainment was not utilized. We targeted the ASC and ablation terminated AAF directly in 19/31 (61.3%) and altered AAF activation in 7/31 (22.6%), all of which terminated directly with additional mapping/ablation. AAF degenerated to atrial fibrillation in 2/31 (6.5%) with RF and could not be reinduced after ASC ablation. Median time from initial ablation to AAF termination was 64 s. Thus, 28/31 (90.3%) terminated with RF energy and/or could not be reinduced after ASC ablation. At 1 year of follow-up, 77% were free of atrial tachycardia or atrial flutter and 61% were free of all atrial arrhythmias.ConclusionsUsing rapidly acquired UHD-ASM, the entire AAF circuit as well as the target ASC could be identified. Most AAF were left atrial macroreentry. Ablation of the ASC or microreentry focuses directly terminated or eliminated AAF in 90.3% without the need for entrainment mapping.
Project description:Background:Catheter ablation (CA) of epicardial accessory pathways (APs) can be performed via the coronary sinus (CS) system. Variable CS anatomy with complications of former CA procedures inside the CS venous system may require using alternative CA approach and technology. Case summary:We report the case of a 23-year-old man with Wolff-Parkinson-White syndrome and history of aborted sudden cardiac death (SCD) and unsuccessful previous AP radiofrequency ablation (RFA). CS venography during the redo procedure revealed an early CS trifurcation with cardiac veins stenosis, thus with difficulties in maintaining cardiac veins' access and catheter manoeuvring inside CS venous system. The last office visit with electrocardiogram (ECG) performance was in 3?months after the CA. Neither delta wave on the ECG nor any complaints/adverse health effects was detected at that time. Discussion:Successful CA of epicardial AP in patients with a high risk of SCD is essential. However, CS complex anatomy and changes after former RFA inside it may lead to CS venous system access limitations. Alternative CA approach and technology should be considered to ensure CS venous system cannulation and epicardial AP CA performance.
Project description:Brain mapping is vital in understanding the brain's functional organization. Electroencephalography (EEG) is one of the most widely used brain mapping approaches, primarily because it is non-invasive, inexpensive, straightforward, and effective. Increasing the electrode density in EEG systems provides more neural information and can thereby enable more detailed and nuanced mapping procedures. Here, we show that the central sulcus can be clearly delineated using a novel ultra-high-density EEG system (uHD EEG) and somatosensory evoked potentials (SSEPs). This uHD EEG records from 256 channels with an inter-electrode distance of 8.6 mm and an electrode diameter of 5.9 mm. Reconstructed head models were generated from T1-weighted MRI scans, and electrode positions were co-registered to these models to create topographical plots of brain activity. EEG data were first analyzed with peak detection methods and then classified using unsupervised spectral clustering. Our topography plots of the spatial distribution from the SSEPs clearly delineate a division between channels above the somatosensory and motor cortex, thereby localizing the central sulcus. Individual EEG channels could be correctly classified as anterior or posterior to the central sulcus with 95.2% accuracy, which is comparable to accuracies from invasive intracranial recordings. Our findings demonstrate that uHD EEG can resolve the electrophysiological signatures of functional representation in the brain at a level previously only seen from surgically implanted electrodes. This novel approach could benefit numerous applications, including research, neurosurgical mapping, clinical monitoring, detection of conscious function, brain-computer interfacing (BCI), rehabilitation, and mental health.
Project description:A 73-year-old woman was admitted for atrial tachycardia (AT) ablation. The activation map and pacing study indicated that the AT propagated around the left pulmonary vein and that the Marshall bundle (MB) bypassed the scar area of the left pulmonary vein ridge and mitral isthmus. The Rhythmia Mapping System revealed double potentials propagated along the assumed position of the MB. The mapping system includes a confidence mask that can be used to visually identify low-confidence areas of the map based upon extremely low-voltage signals. Given the low-voltage area in the endocardial side, the epicardial conduction was emphasized.
Project description:The intent of the experiment was to construct molecular SNP-binning markers of a Col-0 x Pat RIL population, for sensitive QTL mapping. We performed Illumina low-coverage DNA sequencing of plant tissues.