Use of MIBG Scan Images in PVC Ablations (PVC-MIBG)

Three Dimensional Neuro-cardiac Imaging Using 123I-metaiodobenzylguanidine Single Photon Emission Computed Tomography to Guide Premature Ventricular Contractions Ablations

The purpose of this study is to assess if Single Photon Emission Computed Tomography (SPECT) demonstrating cardiac innervation can be integrated into current electrophysiology voltage mapping system and provide improved guidance for ablation of PVCs.

Study Overview

• Status: Completed
• Conditions: Premature Ventricular Contractions
• Intervention / Treatment: Other: MIBG nuclear scan

Detailed Description

Premature ventricular contractions (PVC) are the most common arrhythmia to be observed in the absence of structural heart disease, and 'frequent' PVCs are estimated to occur in 1-4% of the general population.1 Idiopathic PVCs are usually associated with a benign course from the standpoint of arrhythmic death, but often result in significant symptoms for the patient such as palpitations, dizziness, pre-syncope and rarely syncope. More recently, a new concept of PVC- mediated cardiomyopathy has emerged that is reversible with suppression of the PVCs.2 Both of those patient populations are currently targeted with PVC suppressive therapy which often involves as the first step using medical therapy such as a beta blocker, calcium channel blocker or an antiarrhythmic. If those fail or if the patients wants to avoid medical therapy an ablation to eliminate the abnormal myocardial tissue that is the origin of the PVCs is often performed.

Radiofrequency ablation (RFA) for PVCs has been performed for several decades and has a well-defined safety and effectiveness profile in patients with symptomatic frequent ventricular ectopic beats and PVC-induced cardiomyopathy. Successful PVC suppression ≥80% of RV and LV PVCs has been reported to be as high as ~80% using an ablation approach.9 Studies found improvements in patient symptoms with elimination of PVCs. In LV dysfunction following ablation demonstrated a significant inverse correlation between EF and PVC burden before ablation, and a significant post procedural improvement in ejection fraction (EF) in 82% of patients who had abnormal systolic function before ablation.8 Improvement of the overall LV EF ranged from 13%-23% after PVC ablation.5,8,10

Autonomic innervation of the heart plays a major role in the normal regulation of myocardial function, heart rate, and coronary blood flow. Abnormal sympathetic cardiac innervation has been shown to have prognostic value for different heart diseases, e.g. heart transplant, coronary artery disease, heart failure, arrhythmias, etc. Importantly, there is a clear association with an increased cardiac morbidity and mortality in heart diseases. Patients with myocardial infarction as well as patients with heart failure exhibit well recognized abnormalities in autonomic tone. PVCs especially in the setting of preserved EF (normal heart patients) have frequently an automatic/triggered mechanism, which is influenced by the cardiac innervation.

Decreased reuptake by impaired myocardial presynaptic nerve terminals results in a buildup of these catecholamines in the synaptic cleft. This leads to a downregulation of postsynaptic beta-adrenergic receptors, with resultant worsening cardiomyopathy and increased arrhythmogenesis.

Cardiac sympathetic innervation can be directly imaged with commonly used nuclear radioisotope, 123I-meta-iodobenzylguanidine (123I-mIBG). As a norepinephrine analogue, 123I-mIBG is similarly released into the synaptic cleft in response to sympathetic input by presynaptic nerve terminals 123I-metaiodobenzylguanidine (123I-MIBG) allows visualization of the cardiac innervation, which could provide additional information to understand the origin, prognosis and pathophysiology of PVCs and guide potential ablation procedures.

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients requiring PVC ablation

Description

Inclusion Criteria:

• Scheduled for PVC ablation

Exclusion Criteria:

• pregnancy

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Utilization of MIBG imaging for PVC ablations	To determine if MIBG imaging provides decreased PVC ablation time	2 years
Decrease PVC occurrence	Does MIBG imaging allow for treatment that provides improved outcomes in decreasing PVCs	2 years
Increase in Motility	Do MIBG follow-ups demonstrate an improvement in cardiac motility	2 years

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore
• Collaborators: GE Healthcare

Study record dates

Study Major Dates

• Study Start: June 1, 2015
• Primary Completion (Actual): December 31, 2019
• Study Completion (Actual): December 31, 2019

Study Registration Dates

• First Submitted: October 20, 2014
• First Submitted That Met QC Criteria: October 28, 2014
• First Posted (Estimate): October 30, 2014

Study Record Updates

• Last Update Posted (Actual): February 8, 2022
• Last Update Submitted That Met QC Criteria: January 25, 2022
• Last Verified: January 1, 2022

More Information

Terms related to this study

• Keywords: ablation
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Pregnancy Complications; Obstetric Labor Complications; Obstetric Labor, Premature; Cardiac Complexes, Premature; Premature Birth; Ventricular Premature Complexes
• Other Study ID Numbers: HP-00062156