Transseptal Access to the Left Atrium: A Narrative Review of Techniques, Indications, and Device Innovations

Transseptal puncture (TSP) is a critical technique for accessing the left atrium in various structural and electrophysiological cardiac procedures. Originally introduced for diagnostic catheterization in the mid-20th century, it has evolved into a cornerstone of modern interventional cardiology. This article was designed as a targeted narrative review, rather than a systematic or comprehensive review, and synthesizes selected peer-reviewed evidence spanning 1955 to 2025, retrieved through a targeted literature search. We explore the anatomical foundations of TSP, its historical development, and modern refinements such as radiofrequency-assisted puncture, balloon septoplasty, and fluoroless or image-fusion-guided access. Clinical applications—including mitral valve interventions, left atrial appendage closure, and decompression during extracorporeal membrane oxygenation (ECMO)—are reviewed alongside safety considerations and complication management strategies. Advances in imaging modalities, including three-dimensional echocardiography and computed tomography, have enhanced precision and safety. Because of the narrative design, the review emphasizes clinical relevance, procedural applicability, and evidence synthesis without formal risk-of-bias scoring or quantitative evidence grading. Overall, TSP demonstrates a high success rate and low complication profile when performed with appropriate imaging and operator expertise. Ongoing innovation in technique and technology continues to expand its utility across cardiac disciplines.