Endocardial repolarization dispersion in BrS: A novel automatic algorithm for mapping activation recovery interval

INTRODUCTION

Repolarization dispersion in the right ventricular outflow tract (RVOT) contributes to the type-1 electrocardiographic (ECG) phenotype of Brugada syndrome (BrS), while data on the significance and feasibility of mapping repolarization dispersion in BrS patients are scarce. Moreover, the role of endocardial repolarization dispersion in BrS is poorly investigated. We aimed to assess endocardial repolarization patterns through an automated calculation of activation recovery interval (ARI) estimated on unipolar electrograms (UEGs) in spontaneous type-1 BrS patients and controls; we also investigated the relation between ARI and right ventricle activation time (RVAT), and T-wave peak-to-end interval (Tpe) in BrS patients.

METHODS

Patients underwent endocardial high-density electroanatomical mapping (HDEAM); BrS showing an overt type-1 ECG were defined as OType1, while those without (latent type-1 ECG and LType1) received ajmaline infusion. BrS patients only underwent programmed ventricular stimulation (PVS). Data were elaborated to obtain ARI corrected with the Bazett formula (ARIc), while RVAT was derived from activation maps.

RESULTS

39 BrS subjects (24 OType1 and 15 LTtype1) and 4 controls were enrolled. OType1 and post-ajmaline LType1 showed longer mean ARIc than controls (306 ± 27.3 ms and 333.3 ± 16.3 ms vs. 281.7 ± 10.3 ms, p = .05 and p < .001, respectively). Ajmaline induced a significant prolongation of ARIc compared to pre-ajmaline LTtype1 (333.3 ± 16.3 vs. 303.4 ± 20.7 ms, p < .001) and OType1 (306 ± 27.3 ms, p < .001). In patients with type-1 ECG (OTtype1 and post-ajmaline LType1) ARIc correlated with RVAT (r = .34, p = .04) and Tpec (r = .60, p < .001), especially in OType1 subjects (r = .55, p = .008 and r = .65 p < .001, respectively).

CONCLUSION

ARIc mapping demonstrates increased endocardial repolarization dispersion in RVOT in BrS. Endocardial ARIc positively correlates with RVAT and Tpec, especially in OType1.

Multi-chamber speckle tracking imaging and diagnostic value of left atrial strain in cardiac amyloidosis

AIMS

Cardiac amyloidosis (CA) affects the four heart chambers, which can all be evaluated through speckle-tracking echocardiography (STE).

METHODS AND RESULTS

We evaluated 423 consecutive patients screened for CA over 5 years at two referral centres. CA was diagnosed in 261 patients (62%) with either amyloid transthyretin (ATTR; n = 144, 34%) or amyloid light-chain (AL; n = 117, 28%) CA. Strain parameters of all chambers were altered in CA patients, particularly those with ATTR-CA. Nonetheless, only peak left atrial longitudinal strain (LA-PALS) displayed an independent association with the diagnosis of CA or ATTR-CA beyond standard echocardiographic variables and cardiac biomarkers (Model 1), or with the diagnosis of ATTR-CA beyond the validated IWT score in patients with unexplained left ventricular (LV) hypertrophy. Patients with the most severe impairment of LA strain were those most likely to have CA or ATTR-CA. Specifically, LA-PALS and/or LA-peak atrial contraction strain (PACS) in the first quartile (i.e. LA-PALS <6.65% and/or LA-PACS <3.62%) had a 3.60-fold higher risk of CA, and a 3.68-fold higher risk of ATTR-CA beyond Model 1. Among patients with unexplained LV hypertrophy, those with LA-PALS or LA-PACS in the first quartile had an 8.76-fold higher risk for CA beyond Model 1, and a 2.04-fold higher risk of ATTR-CA beyond the IWT score.

CONCLUSIONS

Among STE measures of the four chambers, PALS and PACS are the most informative ones to diagnose CA and ATTR-CA. Patients screened for CA and having LA-PALS and/or LA-PACS in the first quartile have a high likelihood of CA and ATTR-CA.

C42 MULTI–CHAMBER SPECKLE TRACKING IMAGING AND DIAGNOSTIC VALUE OF LEFT ATRIAL STRAIN IN CARDIAC AMYLOIDOSIS

Background

Amyloid deposits in all cardiac chambers, impairing their function. We investigated for the first time if a speckle–tracking echocardiography (STE) analysis extended to all 4 chambers might hold additive diagnostic value for CA and its subtypes (amyloid transthyretin [ATTR–] and light–chain [AL]–CA).

Methods

We evaluated 423 consecutive patients undergoing a diagnostic workup for CA in 2 referral centres from 2015 to 2020.

Results

CA was diagnosed in 261 patients (62%; ATTR–CA, n = 144, 34%; AL–CA, n = 117, 28%). Patients with CA had an impaired function of all cardiac chambers, particularly those with ATTR–CA. Peak left atrial longitudinal strain (LA–PALS) was the only STE parameter that predicted CA and ATTR–CA independent of laboratory and standard echocardiographic variables (Model 1). It also predicted ATTR–CA among patients with unexplained hypertrophy regardless of a diagnostic score (IWT score). Patients with either LA–PALS or LA–peak atrial contraction strain (PACS) in the first quartile (LA–PALS &lt;6.65% or LA–PACS &lt;3.62%) had an almost 4–fold higher likelihood of CA and ATTR–CA regardless of Model 1. Among patients with unexplained hypertrophy, those with LA–PALS or LA–PACS in the first quartile had an almost 9–fold higher likelihood of ATTR–CA irrespective of Model 1, and a 2–fold higher likelihood of ATTR–CA beyond the IWT score.

Conclusions

STE measures of all 4 chambers are abnormal in patients with CA, particularly in those with ATTR–CA. LA strain holds independent diagnostic significance. Among patients screened for CA, those with LA–PALS &lt;6.65% and/or LA–PACS &lt;3.62% have a high likelihood of CA and ATTR–CA.

417 Multi-chamber speckle tracking imaging and diagnostic value of left atrial strain in cardiac amyloidosis

Aims

Amyloid deposits in all cardiac chambers, impairing their function. We investigated for the first time if a speckle-tracking echocardiography (STE) analysis extended to all four chambers might hold additive diagnostic value for CA and its subtypes [amyloid transthyretin (ATTR-) and light-chain (AL)-CA].

Methods and results

We evaluated 423 consecutive patients undergoing a diagnostic workup for CA in two referral centres from 2015 to 2020. CA was diagnosed in 261 patients (62%; ATTR-CA, n = 144, 34%; AL-CA, n = 117, 28%). Patients with CA had an impaired function of all cardiac chambers, particularly those with ATTR-CA. Peak left atrial longitudinal strain (LA-PALS) was the only STE parameter that predicted CA and ATTR-CA independent of laboratory and standard echocardiographic variables (Model 1). It also predicted ATTR-CA among patients with unexplained hypertrophy regardless of a diagnostic score (IWT score). Patients with either LA-PALS or LA-peak atrial contraction strain (PACS) in the first quartile (LA-PALS &lt;6.65% or LA-PACS &lt;3.62%) had an almost 4-fold higher likelihood of CA and ATTR-CA regardless of Model 1. Among patients with unexplained hypertrophy, those with LA-PALS or LA-PACS in the first quartile had an almost 9-fold higher likelihood of ATTR-CA irrespective of Model 1, and a 2-fold higher likelihood of ATTR-CA beyond the IWT score.

Conclusions

STE measures of all two chambers are abnormal in patients with CA, particularly in those with ATTR-CA. LA strain holds independent diagnostic significance. Among patients screened for CA, those with LA-PALS &lt;6.65% and/or LA-PACS &lt;3.62% have a high likelihood of CA and ATTR-CA.