Cardiac phase variability in pulmonary root geometry: implications for electrophysiological mapping and ablation.

Area of Science:

• Cardiovascular Imaging and Electrophysiology
• Cardiac Anatomy and Dynamics

Background:

• The pulmonary root is a key target for ventricular arrhythmia ablation.
• Current mapping systems assume static cardiac geometry, which is inaccurate for the dynamic pulmonary root.

Purpose of the Study:

• To quantify the geometric, morphometric, and positional changes of the pulmonary root between systole and diastole.
• To establish reference values for pulmonary root dynamics in electrophysiological interventions.

Main Methods:

• Analysis of ECG-gated contrast-enhanced CT angiography (CTA) in 100 adult patients.
• Generation of 3D reconstructions for systolic and diastolic phases.
• Measurement of morphometric parameters and quantification of displacement and angulation.

Main Results:

• The pulmonary root exhibits significant dimensional variability, especially the basal ring (32.3% area reduction).
• Substantial 3D displacement (median 8.0 mm) and angulation changes (5.6° sagittal increase) occur during systole.
• Pulmonary root volume increases by 4.1% during systole (p=0.001).

Conclusions:

• The pulmonary root's substantial cardiac cycle-dependent motion challenges current electroanatomical mapping assumptions.
• Findings impact catheter stability, procedural planning, and the development of motion-compensated technologies for electrophysiology.