MCG In Long QT Syndrome

NCT07270211 | Not Yet Recruiting

• 1 other identifier: 25-008283
• Study Type: observational
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

The primary objective of this observational study is to evaluate whether magnetocardiography (MCG) findings more accurately predict clinical outcomes in patients with acquired Long QT syndrome compared to ECG. The secondary objective is to assess differences in QT interval length between MCG and ECG. The primary safety objective is to characterize the safety profile of the CardiAQ MCG device.

Conditions

Atrial Fibrillation

Outcome Measures

Primary Outcomes (2)

• Number of successful dofetilide loading using Magnetocardiography

  Dofetilide loading is considered successful if the following conditions are met: 1. No excessive QTc prolongation QTc remains \<500 ms, and no \>15% increase from baseline. 2. No sustained VT or recurrent/symptomatic non-sustained VT (NSVT) suggestive of proarrhythmia. 3. No symptomatic bradycardia or hemodynamic instability 4. Stable renal function 5. No deterioration necessitating dose reduction or discontinuation. 6. Discharge on a stable dose

  Baseline

• Number of successful dofetilide loading using Electrocardiogram

  Dofetilide loading is considered successful if the following conditions are met: 1. No excessive QTc prolongation QTc remains \<500 ms, and no \>15% increase from baseline. 2. No sustained VT or recurrent/symptomatic non-sustained VT (NSVT) suggestive of proarrhythmia. 3. No symptomatic bradycardia or hemodynamic instability 4. Stable renal function 5. No deterioration necessitating dose reduction or discontinuation. 6. Discharge on a stable dose

  Baseline

Secondary Outcomes (2)

• Magnetocardiography - QT interval length

  Baseline

• Electrocardiogram - QT interval length

  Baseline

Study Arms (1)

Subjects diagnosed with atrial fibrillation

Diagnostic Test: Magnetocardiography

Interventions

Magnetocardiography DIAGNOSTIC_TEST

MCG is a non-invasive, radiation-free imaging technique that detects the magnetic field generated by the electrical activity of the heart.

Subjects diagnosed with atrial fibrillation

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Study candidates may be identified and recruited in one of the following ways: * In-patient service at the study institution. * From the Principal Investigator or Co-Investigator clinical practices * Referral from other hospitals * Cardiology Specialty Clinics

You may qualify if:

• Age ≥ 18 years on the date of consent
• Ability for participant to comply with study requirements
• Written informed consent
• Confirmed diagnosis of atrial fibrillation and receiving dofetilide for rhythm control in the inpatient setting.

You may not qualify if:

• Pregnant or breastfeeding
• Active thoracic metal implants (including pacemaker, insertable cardiac monitor, or internal defibrillators).
• External electrical pads or devices (e.g. Pacer pads, ECG electrodes, heart rate patch), that must remain on patient's chest during MCG scan
• Inability to lie down in a supine/inclined position and stay still on the examination bed
• Clinical conditions that in the opinion of the Investigator would compromise the safety of the patient or ability to complete the protocol

Sponsors & Collaborators

• Mayo Clinic: lead

Study Sites (1)

Mayo Clinic in Rochester

Rochester, Minnesota, 55905, United States

Location

MeSH Terms

Conditions

Atrial Fibrillation

Interventions

Magnetocardiography

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Heart Function Tests; Diagnostic Techniques, Cardiovascular; Diagnostic Techniques and Procedures; Diagnosis; Electrodiagnosis; Magnetometry; Investigative Techniques

Study Officials

• Mohamad Alkhouli, M.D., M.B.A.

  Mayo Clinic

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Patsy Caceres Figueroa

CONTACT

507-266-3054; caceresfigueroa.patsy@mayo.edu

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: November 25, 2025
• First Posted: December 8, 2025
• Study Start: April 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: March 5, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)