The Mercator Atrial High-Density Array Catheter, used in conjunction with the Cardiac Pathways' Model 8100 Arrhythmia Mapping System and the Model 8300 Signal Acquisition Module, is intended to be used in the right atrium of patients with complex arrhythmias that may be difficult to identify using conventional mapping systems alone (i.e., linear mapping catheters). The system is used to record intracardiac electrogram (EGM) signals and to deliver pacing pulses for the purpose of diagnostic provocative stimulation during an electrophysiology procedure.

Device Description

The Mercator High Density Array Catheter has an 8.5F catheter shaft with a collapsible, spheroidal-shaped, 32 bipole electrode array on the distal end, and an integrated cable/connector assembly on the proximal end. The device is designed to interface with the Cardiac Pathways' Arrhythmia Mapping System. There are three sizes of arrays for the right atrium based on the atrial volume derived from transthoracic echocardiograms: 70 cc, 100 cc, and 130 cc.

The electrode array consists of eight equidistant arms fixed at each end to form a spheroid. The arms terminate into an atraumatic tip on the distal end, and transition into the catheter shaft on the proximal end. The arms are made of a compliant material that maintains contact against the atrial walls during the cardiac cycle. The arms are labeled A through H in a clockwise direction. The array orientation is ascertained using three radiopaque markers positioned on arms A (distal), B (mid) and C (proximal). Each arm has four electrode pairs spaced equidistant from each other along the length of each arm. Each electrode is 0.75 mm wide by 0.25 mm high. The electrode spacing is the same for all three sizes of catheters: 1 mm between electrodes in a bipole and 8 mm between bipoles when measured center to center.

The electrical connections between the electrodes on the array and the connector on the proximal end of the catheter are made via cables. The cables run the length of the catheter shaft and connector bump tubing. The catheter shaft terminates at the proximal end at the Y-arm assembly. The center lumen of the catheter is contiguous with the luer fitting on the straight arm of the Y-arm assembly and is used for flushing the catheter. The angled arm on the Y-arm assembly provides the interface for the connector bump tubing.

The connector has 79 pins, and interfaces with a mating receptacle on the Arrhythmia Mapping System. The terminations of the cables at the connector are housed inside a backshell that provides a smooth transition from the connector to the connector burnp tubing.

The 11 F Guiding Sheath and the 30° Angled Guiding Sheath have an 11 F braided catheter shaft that terminates into a short, atraumatic tip on the distal end and a luer fitting on the proximal end. On the 30° Angled Guiding Sheath, the distal 4.5 cm of the catheter shaft is angled 30° from the proximal shaft of the catheter. The 11 F Guiding Sheath and the 30° Angled Guiding Sheath are used in conjunction with the 8.5 F Pigtail Catheter and the 30° Angled 8.5 F Pigtail Catheter, respectively, to position the High Density Array Catheter in the right atrium.

The 11 F Guiding Sheaths have a large inside diameter through which the High Density Array Catheter is inserted into and withdrawn from the cardiovascular system. The shaft of the Guiding Sheath is radiopaque. The Guiding Sheath terminates into a female luer fitting on the proximal end. This luer fitting is used to flush the Guiding Sheath and to introduce the High Density Array Catheter into the Guiding Sheath. The working length of the Guiding Sheath is 110 cm.

The purpose of the Guiding Sheath is to "guide" the High Density Array Catheter to a position in the right atrium found using the 8.5 F Pigtail Catheter. The Guiding Sheath is also used to collapse and withdraw the electrode array on the High Density Array Catheter when mapping is complete

The 8.5 F Pigtail Catheter and the 30° Angled 8.5 F Pigtail Catheter have an 8.5 F braided catheter shaft on the proximal end attached to a soft distal extrusion that is necked down and formed into a radius known as a " pigtail". The 8.5 F Pigtail Catheter and the 30° Angled 8.5 F Pigtail Catheter are used in conjunction with the 11 F Guiding Sheath to position the High Density Array Catheter in the right atrium.

The Pigtail Catheters have an open center lumen and 12 side holes positioned equidistant from each other in the distal extrusion, proximal to the pigtail. These holes can be used to deliver contrast media into the right atrium for visualization of catheter position and to assess the size of the atrium. The center lumen is accessible for flushing using a female luer lock fitting on the proximal end of the Pigtail Catheter. The braided shaft is radiopaque and gives the catheter good torque transmission.

The diameter of the pigtail tip is 1.3 cm. The purpose of this large diameter tip is to facilitate atraumatic placement into the right atrium. It also helps to avoid prolapsing of the High Density Array Catheter through the tricuspid valve into the right ventricle. The working length of the Pigtail Catheter is 135 cm.

A pigtail stylet is packaged in the Deployment Kit to straighten out the distal radius of the pigtail when inserting it inside the Guiding Sheath. The stylet is a stainless steel mandrel with a ball on the end to prevent advancing it all the way into the center lumen of the Pigtail Catheters. The pigtail stylet is used only in the preparation of the Guiding Sheath/Pigtail Catheter assembly and is not intended to be inserted into a patient. It is removed after the Pigtail Catheter is positioned inside the Guiding Sheath.

AI/ML Overview

The Mercator Atrial High Density Array Catheter is intended to record intracardiac electrogram (EGM) signals and to deliver pacing pulses for diagnostic provocative stimulation during an electrophysiology procedure in the right atrium of patients with complex arrhythmias.

Here is an analysis of its acceptance criteria and the study proving its performance:

1. Acceptance Criteria and Reported Device Performance

The provided document does not explicitly list quantitative acceptance criteria for the device's performance. Instead, it focuses on demonstrating substantial equivalence to predicate devices. The performance data assesses diagnostic quality, signal quality, rhythm interpretations, and baseline noise compared to standard catheters. Since the device is intended to enable diagnosis, the ability to successfully record and interpret signals is paramount.

Performance Metric	Acceptance Criteria (Implied by Equivalence Study)	Reported Device Performance
Diagnostic Quality (Sinus Rhythm)	Equivalent to standard diagnostic commercial catheters (p=1.000)	Overall diagnostic quality in sinus rhythm rated as "identical" between HDAC and standard catheters (p = 1.000). Recordings acceptable for diagnosis in all patients with both devices. Rhythm diagnosis was sinus rhythm in all cases with both devices.
Signal Quality (Sinus Rhythm)	Similar to standard diagnostic commercial catheters (p=0.8643)	Overall signal quality in sinus rhythm rated as "similar" between HDAC and standard catheters (p = 0.8643).
Diagnostic Quality (Atrial Arrhythmia)	Similar to standard diagnostic commercial catheters (p=0.1177 and Kappa = 0.799)	Overall diagnostic quality in atrial arrhythmia rated as "similar" between HDAC and standard catheters (p = 0.1177). Recordings acceptable for diagnosis in all patients with both devices. Arrhythmia diagnoses were similar with the two devices (Kappa = 0.799).
Signal Quality (Atrial Arrhythmia)	No difference from standard diagnostic commercial catheters (p=0.4559)	Overall signal quality in atrial arrhythmia showed "no difference" among catheters (p = 0.4559).
Baseline Noise	Equivalent to standard diagnostic commercial catheters (p=0.5450 for mean, p=0.8970 for patient mean)	Mean baseline noise per electrode pair: 0.019 ± 0.096 mV for HDAC vs. 0.016 ± 0.075 mV for standard catheters (p = 0.5450). Proportion of electrode pairs with baseline noise: 6.8% for HDAC vs. 7.6% for standard catheters. Mean baseline noise per patient was similar for both devices (p = 0.8970). Equivalence was demonstrated regardless of comparison method.
Pacing Capture Consistency	High consistency (no specific threshold given, but "consistent capture" is implied as positive performance feedback)	Consistent capture of one or more bipole pairs at 5 mA was achieved in 96.9% of patients. Pacing capture was also determined at 2 mA.
Safety Profile	Excellent safety profile compared to comparison groups, no major adverse events related to the device itself (e.g., thromboembolism, perforation, valve injury, thrombus on catheter)	No instances of thromboembolic events, cardiac perforation, or valve injury reported. No evidence of thrombus on 92 inspected HDAC catheters. One procedure-related major adverse event (left femoral hematoma) not directly attributed to the device design itself. Three minor, procedure-related adverse events occurred, also not directly attributed to the device design.

2. Sample Size and Data Provenance

Test Set Sample Size: 74 patients for data analysis in the clinical study. A total of 79 patients were enrolled, but 5 were excluded because the HDAC was not deployed.
- For matched electrogram analysis in sinus rhythm: 41 patients.
- For matched electrogram analysis in atrial arrhythmia: 45 patients.
Data Provenance: Prospective clinical study conducted at eight centers. The country of origin is not explicitly stated, but given the FDA 510(k) submission, it is almost certainly a US-based study or a multinational study that includes US sites.

3. Number of Experts and Qualifications for Ground Truth

Number of Experts: A "blinded independent expert" was used to perform the primary analyses of equivalence. Only one expert is explicitly mentioned for this comparative assessment.
Qualifications of Experts: The specific qualifications (e.g., "Radiologist with 10 years of experience") are not detailed for the independent expert, only that they were an "expert." For an electrophysiology study, such an expert would typically be an electrophysiologist with significant experience in interpreting intracardiac electrograms.

4. Adjudication Method

The document states that the "primary analyses of equivalence... were performed by a blinded independent expert." This suggests a single expert's interpretation formed the basis of the comparison without an explicit multi-reader adjudication method (e.g., 2+1 or 3+1 consensus). However, the study also compared diagnoses to "predefined diagnostic categories," implying a structured framework for assessment.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No Multi-Reader Multi-Case (MRMC) comparative effectiveness study was explicitly mentioned to assess how much human readers improve with AI vs. without AI assistance. The study focuses on the standalone performance of the device and its equivalence to predicate devices, with human readers (the "independent expert") evaluating the quality of the signals from both the investigational and predicate devices. This device is a diagnostic catheter, not an AI assistance tool.

6. Standalone Performance Study (Algorithm-Only)

A standalone performance study was done in the sense that the device's ability to record and pace was evaluated on its own merits alongside the comparison to predicate devices. The study assessed:

The device's ability to capture pacing (96.9% consistent capture at 5 mA).
The intrinsic qualities of its recorded electrograms (diagnostic quality, signal quality, baseline noise) as interpreted by an expert, compared to standard catheters.
The device's mechanical and electrical specifications compliance through laboratory testing. These are inherently "standalone" assessments of the device itself.

7. Type of Ground Truth Used

The ground truth for the clinical study was primarily established by:

Expert Interpretation/Diagnosis: The "blinded independent expert" determined the diagnostic quality, rhythm diagnoses, and signal quality based on the electrogram recordings. This represents expert consensus on the interpretation of physiological signals.
Patient Diagnosis/Medical History: The study population itself had verified arrhythmias (e.g., atrial flutter, AV nodal tachycardia), which served as the clinical context for evaluating the diagnostic performance of the catheters.
Objective Measurements: For baseline noise, objective measurements (peak-to-peak absolute amplitude) were taken from the signals.

8. Sample Size for the Training Set

This document describes a clinical validation study and does not mention a "training set" in the context of an AI/machine learning algorithm, as the device itself is a physical medical instrument (catheter), not a software algorithm that requires a training set. The clinical study acts as the validation set for the device's performance against its intended use.

9. How the Ground Truth for the Training Set was Established

As mentioned above, there is no "training set" in the context of an AI/machine learning algorithm for this device. The physical device's design and engineering would have been guided by prior medical knowledge, engineering principles, and potentially animal or bench testing (which are not detailed here for ground truth establishment). The ground truth for the clinical validation was established through expert interpretation of electrograms and patient clinical diagnosis.

Summary

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Mercator Atrial High Density Array Catheter

JAN 27 1999

K982540

APPENDIX F

REVISED 510(K) SUMMARY FOR THE MERCATOR ATRIAL HIGH DENSITY ARRAY CATHETER

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510(k) SUMMARY

Indications

The Mercator Atrial High-Density Array Catheter, used in conjunction with the Cardiac Pathways' Model 8100 Arrhythmia Mapping System and the Model 8300 Signal Acquisition Module, is intended to be used in the right atrium of patients with complex arrhythmias to record intracardiac electrogram (EGM) signals and to deliver pacing pulses for the purpose of diagnostic provocative stimulation during an electrophysiology procedure.

Device Description

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Predicate Devices

The Mercator Atrial High Density Array Catheter is substantially equivalent to Woven Dacron® Electrode Catheters and Atrial Mapping Electrode Catheters manufactured by Bard Electrophysiology, the Explorer ST™ Fixed Curve Diagnostic Catheter manufactured by EP Technologies, and Fixed Tip Electrophysiology Catheters and the Deflectable Halo Electrophysiology Catheters manufactured by Webster Laboratories.

Performance Data

The Mercator Atrial High Density Array Catheter, the Guiding Sheaths, and the Pigtail Catheters were subjected to a battery of electrical and mechanical tests to verify that the devices met the specifications. Electrical testing included, but were not limited to, assessment for continuity and short circuits, DC impedance, AC impedance, capacitance, and dielectric strength and current leakage. The device met the specifications. Mechanical testing included, but was not limited to, assessment of joint strengths and the forces required to insert and withdraw the devices. The device met the specifications. Biocompatibility testing was performed to verify that the devices did not elicit toxicological responses.

Clinical testing was performed in accordance with an Investigational Device Exemption granted by the FDA. A total of 79 patients were enrolled in this study at eight centers. A total of 74 patients were included in the data analysis; five patients were excluded from analysis because the HDAC was not deployed in the heart. The patient population had a mean age of 51.6 years, and the gender distribution was 54% male and 46% female. Fifty-one percent of patients had a history of atrial flutter or fibrillation. The majority of patients (55%) had other co-existing chronic conditions. Thus, the patients in this study were somewhat older than a typical supraventricular tachycardia population. The most common arrhythmia study diagnoses were atrial flutter in 30%, atrioventricular nodal tachycardia in 18%, supraventricular tachycardia in 18%, and atrial tachycardia in 16% of patients. The electrophysiology procedure included the performance of radiofrequency catheter ablation in 88% of patients, and was considered acutely successful in 89% of those undergoing ablation.

A total of 92 HDACs were deployed in 74 patients. The selection of HDAC size was based in part upon measurements of end-systolic right atrial dimensions obtained from the pre-procedure echocardiogram. Larger HDAC sizes were used in patients with larger right atrial dimensions. In patients with normal right atrial dimensions, the 70 cc HDAC was always chosen.

Atrial pacing capture was determined for each bipole pair at 2 mA and at 5 mA. Consistent capture of one or more bipole pairs at 5 mA was achieved in 96.9% of patients.

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The primary analyses of equivalence between the HDAC and predicate devices (diagnostic commercial catheters) were performed by a blinded independent expert. The analyses involved comparing electrograms from both devices in sinus rhythm and the atrial arrhythmia.

Electrogram recordings were obtained during sinus rhythm with standard catheters in 88% of patients and with the HDAC in 82% of patients. Recordings were obtained during the atrial arrhythmia in 81% of patients with standard catheters and in 78% of patients with the HDAC.

Matched sets of electrogram data in sinus rhythm for both standard catheters and the HDAC were available for analysis by the independent expert for 41 patients. The overall diagnostic quality in sinus rhythm was rated as identical (p = 1.000). With both devices, recordings were acceptable to make a diagnosis of sinus rhythm in all patients. The rhythm diagnosis was sinus rhythm in all cases with both devices. The overall signal quality was rated as similar (p = 0.8643).

Matched sets of electrogram data in the atrial arrhythmia for standard catheters and the HDAC were available for analysis by the independent expert for 45 patients. The overall diagnostic quality was rated as similar (p = 0.1177). The recordings were acceptable to make a diagnosis of atrial arrhythmia in all patients with standard catheters and the HDAC. Using predefined diagnostic categories, the arrhythmia diagnoses were similar with the two devices (Kappa = 0.799). The overall signal quality also manifested no difference among catheters (p = 0.4559).

Baseline noise was evaluated by the independent expert, who measured the peak-to-peak absolute amplitude of noise on individual signals. The mean baseline noise recorded per electrode pair was 0.016 ± 0.075 mV for standard catheters and 0.019 ± 0.096 mV for the HDAC (p = 0.5450). The proportion of electrode pairs with baseline noise recorded was 7.6% for standard catheters and 6.8% for the HDAC. The mean baseline noise recorded for each patient was also similar for both devices (p = 0.8970). Regardless of the way in which absolute peak to-peak noise was compared, the standard catheter and HDAC were equivalent.

Patients were anticoagulated using intravenous heparin, and activated clotting time (ACT) levels were used to guide heparin administration. The mean baseline ACT was 126.0 ± 20.7 sec, and the mean ACT on heparin was 257.0 ± 52.2 sec. The mean ACT level using linear regression analysis was stable over time, achieving a range of 1.5-2.5 times the baseline value.

Safety was evaluated based upon the findings of the pre-discharge echocardiogram, the pre-discharge history and physical examination, and the examination of the HDAC immediately after removal. There were no instances of thromboembolic events, cardiac perforation, or valve injury. There was no evidence of thrombus on the 92 HDAC

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catheters visually inspected immediately following removal from the patient. One procedure-related major adverse event (1.35%) occurred involving a left femoral hematoma in a patient in whom the HDAC was inserted into the right femoral vein. Three minor, procedure-related adverse events occurred, one case of transient Type I (Wenckebach) AV block and pleuritic chest pain, one case of chest pain probably related to radiofrequency catheter ablation, and a third case of oropharyngeal edema attributed to an allergic reaction from a sedative used during the procedure.

In conclusion, the data supports the comparability of the HDAC with standard (linear) diagnostic electrophysiology catheters. Specifically, the ability to make an arrhythmia diagnosis in all cases with either catheter, similar diagnostic quality, similar rhythm interpretations, similar signal quality, and similar absolute baseline noise. The functionality was adequately defined regarding pacing and recording capabilities. The HDAC demonstrated an excellent safety profile compared to comparison groups of patients undergoing either diagnostic electrophysiology studies or radiofrequency catheter ablation for supraventricular tachyarrhythmia with standard linear mapping. The three sizes and shapes of the HDAC appeared appropriate for the intended patient population. The data supports the use of the HDAC as a diagnostic tool for the recording of multiple intracardiac electrograms and delivery of pacing stimuli to the right atrium.

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Image /page/6/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle with three lines forming its body and wings. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

JAN 27 1999

Ms. Erin Dignan Manager, Regulatory Affairs Cardiac Pathways, Corp. 995 Benecia Avenue Sunnyvale, CA 94086

Re: K982540 Mercator™ Atrial High Density Array Catheter Regulatory Class: II (two) Product Code: MTD - High density array intracardiac mapping catheter Dated: October 28, 1998 Received: October 29, 1998

Dear Ms. Dignan:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Druq, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act and the limitations described below. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

The Office of Device Evaluation has determined that there is a reasonable likelihood that this device will be used for an intended use not identified in the proposed labeling and that such use could Therefore, in accordance with Section 513(i)(1)(E) of the cause harm. Act, the following limitation must appear in the Warnings section of the device's labeling:

WARNING: The use of this device in conjunction with radiofrequency ablation, as part of the diagnosis and treatment of cardiac arrhythmias, may pose an increased risk of adverse events, such as cardiac perforation, myocardial infarction, air embolism, and hematoma requiring surgical repair and/or blood transfusion.

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Page 2 - Ms. Erin Dignan

The Warning must be presented within a black box, and the font size of the text should be at least 2 points larger than any surrounding text. The Warning must be present on the first page of your Operator's Manual, and on the packaging for each individual device.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 A substantially equivalent determination assumes compliance to 895. with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Requlation (QS) for Medical Devices: General requlation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in requlatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and permits your device to proceed to the market. This letter will allow you to begin marketing your device as described in your 510(k) premarket notification if the limitation statement above is added to your labeling, as described.

Please note that the above labeling limitations are required by Section 513(i)(1)(E) of the Act. Therefore, a new 510(k) is required before these limitations are modified in any way or removed from the device's labeling.

If you desire specific information about the application of other labeling requirements to your device (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4646. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Other general information on your responsibilities under the 807.97). Act may be obtained from the Division of Small Manufacturers

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Page 3 - Ms. Erin Dignan

Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or
e and in the state of the (4mm fels gov/cdrb/dsma/dsmamain.html", Assistance at its toll=Lree number (800) 050 2011 02 (00)
at its Internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours,

Susan Albert, Ph.D., M.B.

Susan Alpert, Ph.D., M Director Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Page 1 of 1

510(k) Number (if known):

Device Name: Cardiac Pathways Mercator ™ Atrial High Density Array Catheter

FDA's Statement of the Indications For Use for device:

V. Carla Mitchell

Prescription Use XX (Per 21 CFR 801.109)

Over-The-Counter Use

Regulation Number and Section

§ 870.1220 Electrode recording catheter or electrode recording probe.

(a)
Identification. An electrode recording catheter or an electrode recording probe is a device used to detect an intracardiac electrocardiogram, or to detect cardiac output or left-to-right heart shunts. The device may be unipolar or multipolar for electrocardiogram detection, or may be a platinum-tipped catheter which senses the presence of a special indicator for cardiac output or left-to-right heart shunt determinations.(b)
Classification. Class II (performance standards).