# Advanced Interatrial Block across the Spectrum of Renal Function

## TL;DR

This study found that advanced interatrial block increases with worsening kidney function and may indicate heart issues in patients with chronic kidney disease.

## Contribution

The study is the first to report the prevalence of partial and advanced interatrial block across stages of chronic kidney disease, including dialysis patients.

## Key findings

- Advanced interatrial block was more common in chronic kidney disease and end-stage kidney disease groups compared to controls.
- Atypical patterns of advanced interatrial block were significantly more frequent in patients with chronic or end-stage kidney disease.
- Patients with end-stage kidney disease were younger and had higher beta blocker use compared to controls.

## Abstract

Background and Objective: Interatrial block (IAB) is defined as a conduction delay between the right and left atria. No data are available about the prevalence of both partial IAB and advanced IAB among the different stages of chronic kidney disease. The aim of this study was to describe the prevalence and type of advanced IAB across the spectrum of renal function, including patients on dialysis and the clinical characteristics associated with advanced IAB. Materials and Methods: Retrospective, single-center study of 151 patients consecutively admitted to the Nephrology and Ophthalmology Unit for 3 months. The study population was divided into three groups according to stages of chronic kidney disease. We evaluated the prevalence and pattern of IAB among the groups and the clinical characteristics associated with advanced IAB. Results: The prevalence of partial IAB was significantly lower in end-stage kidney disease (ESKD) group compared to control group (36.7% vs. 59.6%; p = 0.02); in contrast the prevalence of advanced IAB was significantly higher in both chronic kidney disease (CKD) (17.8% vs. 5.3%, p = 0.04) and ESKD group (24.5% vs. 5.3%, p = 0.005) compared to control group. The atypical pattern of advanced IAB was more frequent in both the ESKD and CKD group than in the control group (100% and 75% vs. 33.3%; p = 0.02). Overall, among patients that showed advanced IAB, 17 (73.9%) showed an atypical pattern by morphology and 2 (8.7%) showed an atypical pattern by duration of advanced IAB. The ESKD group was younger than the control group (65.7 ± 12.3 years vs. 71.3 ± 9.9 years; p = 0.01) and showed a higher prevalence of beta blockers (42.9% vs. 19.3%; p = 0.009), as in the CKD group (37.8% vs. 19.3%; p= 0.04). Conclusions: The progressive worsening of renal function was associated with an increasing prevalence of advanced IAB. Advanced IAB may be a sign of uremic cardiomyopathy and may suggest further evaluation with long-term follow-up to investigate its prognostic significance in chronic kidney disease.