half-normal saline

Half-normal saline (0.45% sodium chloride) is a hypotonic saline solution utilized as an irrigant during radiofrequency (RF) catheter ablation for the treatment of typical cavotricuspid isthmus-dependent atrial flutter. In this procedural context, the solution is delivered through open-irrigated ablation catheters to the target cardiac tissue. The therapeutic rationale is based on the solution's lower ionic concentration compared to standard normal saline (0.9% NaCl), which reduces the electrical conductivity of the medium surrounding the catheter tip. This reduction in conductivity minimizes the dispersion of RF energy into the circulating blood pool and focuses the energy at the catheter-tissue interface. This biophysical modulation facilitates the creation of deeper and more transmural ablation lesions, which aims to reduce the time required to achieve bidirectional conduction block and improve long-term procedural success rates. Sunnybrook Health Sciences Centre has led multicenter clinical investigations (e.g., NCT04001530) to verify its superiority over normal saline in this indication.

Brand names

HAFNOR

Other names

0.45% sodium chloride0.45% NaClhalf-strength saline0.45% Sodium Chloride Injection