This study is designed to collect parallel intracardiac signal data during pre-defined periods of clinical interest from the PURE EP system and the existing signal recording and mapping systems.

The collected signals will then undergo BLINDED, CONTROLLED evaluation by unbiased electrophysiologist reviewer(s) to determine whether the PURE EP signals provides additional or clearer diagnostic information.

Cardiac electrophysiologists rely on the display of electrograms when performing electrophysiology (EP) studies and catheter ablations in patients with arrhythmias. To achieve effective outcomes without complications, it is vital that the recording system enables the recognition of clearly abnormal (scared myocardium) and normal electrical signals.

Current recording systems have limitations in that it can be difficult to clearly distinguish a true cardiac signal from noise or artifact. This is particularly true when pacing the heart and when ablating abnormal myocardial tissue, components of the conduction system or epicardial structures. Therefore, improvement of the fidelity of signals obtained from EP recording systems is needed to enhance identification of the most effective targets for ablation.

There are several standard electrophysiology recording systems in use today, such as the commonly used GE/Prucka CardioLab recording system ("Prucka") which would benefit from additional features in order to improve the ability to record, discriminate and analyze signals from the heart. BioSig Technologies, Inc. ("BioSig") has developed an electrophysiology signal processing system, the PURE EP™ System, which may allow electrophysiologists to better characterize arrhythmogenic tissue during ablation procedures. Specifically, the PURE EP™ System's higher sampling rate and higher dynamic range allow improved visualization of low amplitude signals, especially those temporally situated near low frequency, high amplitude signals or large high-frequency signals.

This multi-center, prospective, non-randomized, observational study will involve at least five patients undergoing elective cardiac ablation procedure for tachycardias such as atrial fibrillation, atypical atrial flutter, ischemic ventricular tachycardia, or symptomatic premature ventricular contractions (PVCs). The existing recording/mapping system clocks will be synchronized to the PURE EP clock prior to each procedure. At the beginning of the procedures, all systems will be optimized for best signal display based on the physician preference. During the ablation procedures, annotations will be captured on the PURE EP system based on pre-determined clinically relevant events defined in this protocol (example - before and after successful ablation therapy).

After the procedures, parallel signal data samples will be harvested from all the systems using the procedure annotations and the time stamps as a guide. Once the signal data is harvested, cleaned, and organized, the individual signal samples will be reviewed in a blinded, controlled fashion by a group of independent, unbiased electrophysiologist(s).

Selected signal sample sets (from the same date and time stamp) will be separated in the survey and arranged in random order. The reviewer will be asked specific and identical questions relevant to each set of signal samples, but the individual samples will be separated and randomized across a full survey containing many different signal samples from many different procedures. The signal survey will be created under the direction of the Principle Investigator. The selection of the independent EP reviewers will also be done under the direction of the Principle Investigator

Inclusion Criteria:

• Indication for cardiac ablation treatment
• Signed informed consent

Exclusion Criteria:

• contraindication to electrophysiology study or ablation
• Enrollment in any other ongoing arrhythmia study protocol
• Active Infection or sepsis
• Pregnancy or lactation
• < 18 years of age

Any person indicated and consented for an elective cardiac ablation procedure who is >18 years of age.

Collected intracardiac signal samples will be shared with the independent electrophysiologist reviewers, other physician investigators, and possibly other study collaborators like a biostatistician and clinical research organization.