Arrhythmia-specific settings for automated high-density mapping: A multicenter experience.

BACKGROUND: Advancements in electrophysiology 3-D mapping systems facilitate the broadening scope of electrophysiology study and catheter ablation to treat complex arrhythmias. While electroanatomical mapping systems have default settings available for a variety of mapping parameters, significant operator customization driven by arrhythmia type and experience can occur. However, multicenter comprehensive reporting of customized mapping settings is lacking. METHODS: In this prospective, multicenter observational registry, subjects with cardiac arrhythmias underwent electrophysiology study and ablation procedure using the EnSite Precision™ electroanatomical mapping system per standard of care, and associated automated mapping thresholds and procedural characteristics were observed. RESULTS: Cardiac mapping and ablation was performed in 503 patients (64.4% male, 59.6 ± 13.2 years) for a variety of indications including atrial fibrillation (N = 277), atrial flutter (N = 67), other supraventricular tachycardias (N = 96), and ventricular tachycardia (N = 56). Automated electroanatomical mapping was used to generate 88.2% of all maps, and arrhythmia-specific adjustments of mapping thresholds were utilized to collect electrophysiologically relevant data. The most commonly used thresholds for mapping in AF were Distance (average 2.7 ± 3.5 mm) and Signal-to-Noise Ratio (5.2 ± 1.1), while mapping in VT commonly used Score (88.5 ± 6.5%) and Distance (0.6 ± 0.5 mm). Automated mapping collected and utilized 8.8 times more data than manual mapping without increasing mapping time. CONCLUSIONS: This registry revealed arrhythmia-specific automated mapping settings used to generate electroanatomical maps of multiple cardiac rhythms with higher point density than manual mapping without increasing mapping time. Commonly used mapping threshold settings could serve as an important reference for new automated electroanatomical mapping users or those expanding their usage to new indications and arrhythmias.

Long-term results of high vs. normal impedance ventricular leads on actual (Real-Life) pacemaker generator longevity.

AIM: The long-term effects of high impedance vs. standard impedance pacing leads on actual generator longevity were studied. METHODS AND RESULTS: In 40 patients (21 females, age 73 +/- 13 years) with standard dual-chamber pacemaker indication, bipolar standard impedance ventricular leads and high-impedance leads were implanted in a randomized fashion. Identical pacemaker generators and atrial pacing leads were implanted in all patients. Patients were observed during a mean follow-up of 89.8 +/- 8.8 months before pacemaker replacement. Initially, the patients who received the high-impedance leads had a lower current drain as compared with standard pacing impedance leads, and the estimated pacemaker longevity was significantly prolonged, too. But this pattern disappeared after 6 years of follow-up, and finally the actual pacemaker generators' replacement time was 86.7 +/- 6.8 months in standard impedance lead group vs. 91.2 +/- 10.3 months in high-impedance lead group (P = 0.17). CONCLUSION: Implantation of high pacing impedance leads for ventricular stimulation does not result in a benefit with respect to pacemaker longevity as compared with standard impedance leads.

Model-based imaging of cardiac electrical excitation in humans.

Activation time (AT) imaging from electrocardiographic (ECG) mapping data has been developing for several years. By coupling ECG mapping and three-dimensional (3-D) + time anatomical data, the electrical excitation sequence can be imaged completely noninvasively in the human heart. In this paper, a bidomain theory-based surface heart model AT imaging approach was applied to single-beat data of atrial and ventricular depolarization in two patients with structurally normal hearts. In both patients, the AT map was reconstructed from sinus and paced rhythm data. Pacing sites were the apex of the right ventricle and the coronary sinus (CS) ostium. For CS pacing, the reconstructed AT pattern on the endocardium of the right atrium was compared with the CARTO map in both patients. The localization errors of the origins of the initial endocardial breakthroughs were determined to be 6 and 12 mm. The sites of early activation and the areas with late activation were estimated with sufficient accuracy. The reconstructed sinus rhythm sequence was in good qualitative agreement with the pattern previously published for the isolated Langendorff-perfused human heart.

Clinical ECG mapping and imaging of cardiac electrical excitation.

Combining electrocardiographic mapping and 3D+time anatomical data enables noninvasively the imaging of the electrical excitation sequence in the human heart. A bidomain-theory based surface heart model activation time imaging approach was employed to image single beat data of atrial and ventricular depolarisation. Activation time maps were reconstructed for three patients who underwent an electrophysiologic study. The sinus rhythm and a rhythm according to a pacing protocol were reconstructed for two patients. For the third patient the accessory pathway of the WPW syndrome was localized. For focal arrhythmias, this model-based imaging approach might allow the guidance and evaluation of antiarrhythmic interventions, for instance, in case of catheter ablation or drug therapy.