New application of NOGA system for qualitative and quantitative analysis of left ventricle rotation in patients with heart failure

Analysis of left ventricular (LV) torsion is a potential new diagnostic parameter for cardiac dysfunction in heart failure patients. In the current work we introduce a new way of 3D rotational analysis by using the 3D electromechanical mapping system NOGA® XP.

Method:

LV rotation was calculated in 10 heart failure patients eligible for CRT implantation using the 3D electromechanical mapping system NOGA® XP (Biosense Webster Inc. USA). Each mapping catheter position was recorded in 3 dimensions at 10 ms intervals and rotation angles were calculated at end-diastolic and end-systolic LV-volume (positive angle values counterclockwise rotation/negative values clockwise rotation). Internal standardized NOGA®-algorithms identified and eliminated points with unstable wall contact and inappropriate rhythm or wall movement. After filtering all data were exported and the respective rotation angles analyzed using external software. After processing, rotation data were transferred into a NOGA® 3D viewer and visualized as color-coded maps. Additionally the data were sorted into standard 9-segment bulls-eye projection according to their anatomical location and analyzed as segmental values.

Results:

A total of 2325 mapping points were evaluated in 10 HF patients. Patients could be classified into 3 different rotation types a) normal twist (apex counterclockwise, base clockwise), b) “rigid body rotation” predominant clockwise (apex and base in clockwise rotation) and c) “rigid body rotation” predominant counterclockwise (apex and base in counterclockwise rotation).

Conclusion:

The method allows a qualitative (clockwise/counterclockwise) and quantitative (absolute degrees) analysis of rotation at each endocardial mapping point and opens an innovative analysis technique to characterize HF-patients based on their electromechanical and LV-rotation characteristics.