# A Case of Transient Complete Heart Block During Left Heart Catheterization

## TL;DR

An 84-year-old man with a pre-existing heart condition experienced a rare complication during a heart procedure, requiring a temporary pacemaker.

## Contribution

Highlights a rare iatrogenic complication during left heart catheterization in patients with pre-existing right bundle branch block.

## Key findings

- A catheter crossing the aortic valve caused transient complete heart block in a patient with pre-existing right bundle branch block.
- The heart block was likely due to left bundle branch blockage from ventricular septal irritation.
- Temporary pacing was required, and the patient tolerated the rest of the procedure.

## Abstract

Iatrogenic complete heart blocks are rare but a reported complication of left heart catheterizations in patients with pre-existing right bundle branch blocks. We present the case of an 84-year-old male with a preexisting right bundle branch block who underwent a left heart catheterization for valve replacement evaluation. While attempting to engage the right coronary artery, the catheter instead crossed the aortic valve, causing the patient to become bradycardic to the 20s and hypotensive. The patient had a temporary transvenous pacer inserted and tolerated the rest of the procedure well. The cause of the complete heart block was thought to be due to the transient blockage of the left bundle branch due to ventricular septal irritation when the catheter crossed the aortic valve. When performing left heart angiograms in a patient with a right bundle branch block, operators should be prepared for a possible iatrogenic complete heart block.