# Relationship between endocardial R-wave amplitude at the apical lead location and regional right ventricular strain analysis

## TL;DR

This study found that higher R-wave amplitude in the heart's apex is linked to better right ventricular strain, helping guide implantable device placement.

## Contribution

The study identifies right ventricular apical strain as an independent predictor of R-wave amplitude, offering a new clinical guidance tool for device implantation.

## Key findings

- Higher R-wave amplitude correlates strongly with improved right ventricular apical strain (correlation coefficient=0.814).
- Right ventricular apical strain is an independent predictor of high R-wave amplitude in multivariable analysis.
- All strain parameters show significant correlation with R-wave amplitude, but apical strain is the strongest predictor.

## Abstract

Cardiac implantable electronic devices are widely used today. Therefore, research is ongoing to provide better device implantation in technical terms. The aim of this study was to investigate the relationship between pre-procedural regional right ventricular strain and post-procedural endocardial R-wave amplitude in patients scheduled to receive an implantable cardiac defibrillator.

A total of 112 patients who underwent single-chamber implantable cardiac defibrillator implantation were included in the study. Right ventricular strain analysis was performed before the procedure, and the following parameters were recorded: four-chamber strain, free wall strain, septal strain, and apical strain. The relationship between R-wave amplitude, calculated after lead implantation in the apical region, and strain parameters was statistically analyzed.

All strain parameters were statistically significantly better in the group with a high R-wave amplitude. Correlation analysis showed that a higher R-wave amplitude was associated with improved right ventricular four-chamber strain (p<0.001, correlation coefficient=0.436), right ventricular free wall strain (p<0.001, correlation coefficient=0.532), right ventricular septal strain (p<0.001, correlation coefficient=0.394), and right ventricular apical strain (p<0.001, correlation coefficient=0.814). In univariable regression analysis, all strain parameters were identified as dependent predictors; however, in multivariable regression analysis, only right ventricular apical strain (p<0.001) was found to be an independent predictor of high R-wave amplitude.

Our study revealed a relationship between the right ventricular apical endocardial R-wave amplitude and all right ventricular strain parameters, especially right ventricular apical strain. We recommend that clinicians perform regional right ventricular strain analysis before implantable cardiac defibrillator implantation in cases where lead positioning is uncertain.