None listed
Conditions
Brief summary
Cardiac catheter ablation is a common treatment for heart rhythm disorders. Catheters are long flexible tubes with electrodes at the tip placed in the heart and deliver heating or cooling thermal injury to disrupt abnormal electrical circuits in the heart (ablation). Many of these circuits are located near the atrioventricular node (AVN), an integral structure of the cardiac electrical system. It is the only normal electrical connection between the top and bottom chambers of the heart maintaining synchronised contraction. Inadvertent damage to the AVN through heating or cooling of nearby structures can result in heart block, requiring pacemaker insertion. This study aims to measure the temperature at the AVN during ablations with a temperature sensor catheter to further understand the AVN properties and reduce the risk of heart block by alerting of its impending damage. This study will assess 2 patient groups; Group 1 will undergo intentional clinically indicated ablation of the AVN with pacemakers in-situ, Group 2 will undergo supraventricular tachycardia (a fast heart rhythm condition) ablations where electrical circuits are located near the AVN. During ablation, electrical measurements will be taken and correlated with AVN temperature. We predict during ablation, the temperature sensing catheter placed at the AVN will detect temperature changes and alter AVN electrical properties which may forewarn operators of imminent heart block, indicative of AVN damage. These findings have potential to enhance patient safety during cardiac ablations, change clinical practice and improve our understanding of the AVN and its properties.
Interventions
Temperature sensing and monitoring of the atrioventricular node using the QDOT MICRO™ catheter (Biosense and Webster, Inc, Irvine, CA). This intervention will replace the standard His Bundle catheter at the His Bundle position (surrogate marker of the atrioventricular node) during cardiac ablation procedures for temperature recording (note: it will not be used for ablation). Recruitment of 2 groups of patients undergoing either atrioventricular node ablation or supraventricular tachycardia ablat
Temperature sensing and monitoring of the atrioventricular node using the QDOT MICRO™ catheter (Biosense and Webster, Inc, Irvine, CA). This intervention will replace the standard His Bundle catheter at the His Bundle position (surrogate marker of the atrioventricular node) during cardiac ablation procedures for temperature recording (note: it will not be used for ablation). Recruitment of 2 groups of patients undergoing either atrioventricular node ablation or supraventricular tachycardia ablation with 20 patients in each where temperature monitoring will occur in both groups. In Group 1, participants will be undergoing clinically-indicated atrioventricular node ablation with permanent pacemakers already in-situ. In Group 2, participants undergoing clinically-indicated supraventricular tachycardia ablations will be consented but only recruited if they have peri-nodal pathways (e.g. atrioventricular nodal re-entrant tachycardia). For both groups, standard electrophysiology study set-up will occur with a decapolar diagnostic electrophysiology catheter in the coronary sinus. Instead of the standard diagnostic electrophysiology catheter placed at the His Bundle location, this will be replaced by the QDOT MICRO™ to measure temperature during ablation. Participants would not receive access to the QDOT MICRO™ if they are not enrolled in the study. A standard mapping system using CARTO3 (Biosense Webster) and intracardiac electrogram analysis system using WorkMate Claris™ (Abbott) will be used. The ablation catheter used will be as per physician discretion and power administration will be standard settings for irrigated (25-35W) or non-irrigated (50W) ablation. During each ablation lesion, temperature recorded by the QDOT MICRO™ at the His Bundle will be correlated to electrophysiology measurements (junctional speeding or atrioventricular block for Group 1) and distance from ablation catheter to His Bundle until the procedure is completed. Operators will be blinded to the temperature at the atrioventricular node. Adherence assessment is not required as this is a same day procedure. The procedures will be performed by cardiac electrophysiologists in a cardiac catheterisation laboratory with vast experience in these procedures. The procedure duration will take a similar time to usual practiceas the only major change is replacing the His catheter; for Group 1 this is approximately 30-60 minutes and for Group 2 this will take around 60-120 minutes. Participants will be followed-up at 3 months as per routine clinical care with review of symptoms and ECG. Materials: baseline and 3-month follow-up 1. Short-Form 36 questionnaire (for general quality of life assessment) https://clinmedjournals.org/articles/jmdt/jmdt-2-023-figure-1.pdf
Sponsors
Melbourne Health - Innovation Acceleration Program
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Diagnosis
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
For Group 1: Adults referred for atrioventricular node ablation procedure a. Permanent pacemaker in situ. For Group 2: Adults referred for supraventricular tachycardia (SVT) ablation procedure (de novo or re-do) a. Preference for patients with suspected atrioventricular nodal re-entrant tachycardia (AVNRT) based on 12-lead ECG of tachycardia during workup of SVT b. Patient will be formally recruited to the study once diagnostic EP study documents peri-nodal SVT with preference for patients with AVNRT (patients will be consented for this prior to procedure)
Exclusion criteria
1. Pregnancy. 2. Age < 18 3. Unable to provide informed consent. 4. No inducible SVT: i.e. no ablation being performed (Group 2) or arrhythmia not peri-nodal
Outcome results
None listed