Concordance of cardiac computed tomography in the identification of deceleration zones and the value of lipomatous metaplasia

 deceleration zones (DZs) evidenced by isochronal late activation mapping (ILAM) have shown a very good sensitivity and specificity for detection of ventricular tachycardia (VT) isthmus. A correlation between these zones and cardiac magnetic resonance imaging (MRI) findings has been demonstrated. Nevertheless, the usefulness of cardiac computed tomography (CCT) in identifying DZs and the role of lipomatous metaplasia (LM) are not well established.

 the objective of this study is to assess the correlation of CCT with DZs evidenced by ILAM and the added value of lipomatous metaplasia to increase the diagnostic accuracy.

 This is an observational study of consecutive patients with structural heart disease who were indicated for ventricular tachycardia ablation from January 2019 to July 2024. All patients underwent a pre-procedural CCT. CCT channels were automatically detected by specific software as well as the presence of lipomatous metaplasia. ILAM was performed via endocardial or epicardial approaches, using a high-density mapping catheter and an electroanatomic navigation system. The correlation between CCT and DZs identified by ILAM was assessed anatomically according to the AHA classification.

a total of 39 patients were included in the study (90% male, 70% with ischemic cardiomyopathy, average LVEF of 33 ± 9.8%). Overall, ILAM maps showed 82 deceleration zones. Sensitivity of CCT to detect these DZ areas was 70% but the positive predictive value was low (PPV 34 %) that increased slightly when considering only CCT channels associated with lipomatous metaplasia (PPV 50%). When analyzing the results by type of cardiomyopathy, there is an improvement in the detection of DZs by CCT in patients with ischemic cardiomyopathy (ICM) compared to other types of cardiomyopathies (PPV 40% vs 20%, respectively).

Conclusión: CCT shows a moderate sensitivity to detect DZs, with improved effectiveness of this imaging technique in patients with ICM and when channels are in contact with LM.