# Implications of Intra-Myocardial Fat Deposition upon Propensity for Malignant Arrhythmia

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2020 · $611,025

## Abstract

Life-threatening ventricular tachycardia (VT) remains a major complication of myocardial infarction. Catheter
ablation aims to destroy the VT substrate, diseased myocardium that slows local conduction sufficiently to
perpetuate circuit reentry. The current understanding of the VT substrate revolves around the interaction of
surviving strands of viable myocardium primarily at the periphery of infarct scar. Our preliminary data, however,
suggests that critical VT circuit sites are viable myocardial strands that reside in the scar core, and are often
surrounded by intra-myocardial fat deposition. Intra-myocardial fat is not a simple bystander; it is metabolically
active and vascular, an effective insulator of conductive fibers, and modulates local conduction properties. This
proposal will investigate the mechanistic consequence of intra-myocardial fat deposition upon impulse
conduction and the propensity to sustain VT in adults with prior myocardial infarction. We propose to use MRI
and CT images of patients with post-infarct VT to 1) to define the prevalence and distribution of myocardial fat
deposition in patients with prior infarction and VT, 2) to characterize the conduction and repolarization
properties of viable channels within scar based upon proximity to myocardial fat, 3) to examine the association
of VT circuit sites with proximity to myocardial fat, and 4) to dissect the contribution of myocardial fat to VT
events using patient-specific models, and to evaluate the diagnostic performance of model-predicted optimal
ablation sites with and without inclusion of myocardial fat. Our group has extensive experience with MRI safety
and image optimization in defibrillator recipients. Additionally, we have assembled a team of experts in image
acquisition and analysis, epidemiology, biostatistics, simulations, and VT management. The findings of this
study will have wide applicability to our mechanistic understanding and management of post-infarct VT.

## Key facts

- **NIH application ID:** 9971585
- **Project number:** 5R01HL142893-03
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Saman Nazarian
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $611,025
- **Award type:** 5
- **Project period:** 2018-08-10 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9971585

## Citation

> US National Institutes of Health, RePORTER application 9971585, Implications of Intra-Myocardial Fat Deposition upon Propensity for Malignant Arrhythmia (5R01HL142893-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9971585. Licensed CC0.

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