scholarly journals A novel algorithm for 3-D visualization of electrogram duration for substrate-mapping in patients with ischemic heart disease and ventricular tachycardia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254683
Author(s):  
Mustafa Masjedi ◽  
Christiane Jungen ◽  
Pawel Kuklik ◽  
Fares-Alexander Alken ◽  
Ann-Kathrin Kahle ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Ischemic Cardiomyopathy ◽  
Heart Association ◽  
Processing Parameters ◽  
Diagnostic Odds Ratio ◽  
Low Noise ◽  
Border Zone ◽  
Arrhythmogenic Substrate ◽  
Basket Catheter ◽  
Novel Algorithm

Background Myocardial slow conduction is a cornerstone of ventricular tachycardia (VT). Prolonged electrogram (EGM) duration is a useful surrogate parameter and manual annotation of EGM characteristics are widely used during catheter-based ablation of the arrhythmogenic substrate. However, this remains time-consuming and prone to inter-operator variability. We aimed to develop an algorithm for 3-D visualization of EGM duration relative to the 17-segment American Heart Association model. Methods To calculate and visualize EGM duration, in sinus rhythm acquired high-density maps of patients with ischemic cardiomyopathy undergoing substrate-based VT ablation using a 64-mini polar basket-catheter with low noise of 0.01 mV were analyzed. Using a custom developed algorithm based on standard deviation and threshold, the relationship between EGM duration, endocardial voltage and ablation areas was studied by creating 17-segment 3-D models and 2-D polar plots. Results 140,508 EGMs from 272 segments (n = 16 patients, 94% male, age: 66±2.4, ejection fraction: 31±2%) were studied and 3-D visualization of EGM duration was performed. Analysis of signal processing parameters revealed that a 40 ms sliding SD-window, 15% SD-threshold and >70 ms EGM duration cutoff was chosen based on diagnostic odds ratio of 12.77 to visualize rapidly prolonged EGM durations. EGMs > 70 ms matched to 99% of areas within dense scar (<0.2 mV), in 95% of zones within scar border zone (0.2–1.0 mV) and detected ablated areas having resulted in non-inducibility at the end of the procedure. Ablation targets were identified with a sensitivity of 65.6% and a specificity of 94.6% avoiding false positive labeling of prolonged EGMs in segments with healthy myocardium. Conclusion The novel algorithm allows rapid visualization of prolonged EGM durations. This may facilitate more objective characterization of arrhythmogenic substrate in patients with ischemic cardiomyopathy.

scholarly journals Effect of adipose graft transposition procedure (AGTP) on the ischemic arrhythmogenic substrate: an MRI study in a swine model of chronic myocardial infraction

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
R Adelino Recasens ◽  
C Galvez-Monton ◽  
A Teis ◽  
D Martinez-Falguera ◽  
O Rodriguez-Leor ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Sham Group ◽  
Left Ventricular ◽  
Post Treatment ◽  
Border Zone ◽  
Left Ventricular Ejection ◽  
Reparative Therapy ◽  
Arrhythmogenic Substrate ◽  
Myocardial Infraction ◽  
Lge Cmr

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III BACKGROUND Cardiac regenerative therapy is a promising treatment for patients with myocardial infarction (MI) and heart failure. Nevertheless, previous ex-vivo studies have raised concern on the potential increased risk of arrhythmic events following certain cell therapies. Adipose graft transposition procedure (AGTP) is a cardiac reparative therapy consisting in transposing a vascularized adipose flap from the autologous pericardium and placing it over the epicardial scar area and has demonstrated to reduce infarct size and improve the left ventricular ejection fraction in preclinical and human studies. PURPOSE To assess the effect of the AGTP on the post-MI scar composition and image-based ventricular tachycardia (VT) corridors detection by means of late gadolinium enhanced cardiac magnetic resonance (LGE-CMR). METHODS A left circumflex artery (first marginal branch) MI was induced in 9 Landrace X Large White Pigs by delivering 1-3 coils. Two weeks post-MI, all subjects underwent a 3 Tesla LGE-CMR and randomized to the AGTP or sham group. LGE-CMR was repeated 30 days post-treatment (6 weeks post-MI). The arrhythmogenic substrate was characterized with an advanced image post-processing tool (ADAS 3D) and included quantification of dense scar and border zone (BZ) mass and detection of ventricular tachycardia (VT) corridors (including corridor scar mass). RESULTS The overall scar mass did not differ between scans in the overall population (7.6 ± 3.5 g vs 7.5 ± 2.2 g in the baseline and post-treatment scans, respectively; p = 0.9). Compared to the sham subjects, those receiving AGTP showed an absolute reduction of the total (-3.2 ± 1.4 g vs. +2.4 ± 1.7 g, p = 0.04) and dense scar (-0.9 ± 0.4 g vs. +0.7 ± 0.5 g, p = 0.03). BZ mass tended to decrease in the AGTP group (-2.2 vs 1.63 g; p = 0.06). The AGTP group showed a trend to reduce the number of VT corridors (-1 ± 0.7 vs. +0.4 ± 0.2, p = 0.078) and corridor scar mass (-0.3 ± 0.26 g vs. +0.1 ± 0.1 g, p = 0.11) (figure). CONCLUSIONS Cardiac reparative therapy of MI with AGTP reduced dense scar mass, compared to the increase observed in the sham group. The trend to reduce the BZ mass and the number/mass of VT corridors suggests a beneficial effect on the arrhythmic remodeling of the post-MI scar. Abstract Figure. Reduction in corridor"s number

Ventricular Tachycardia Induced by Biventricular Pacing in Patient with Severe Ischemic Cardiomyopathy

2005 ◽  
Vol 16 (6) ◽  
pp. 655-658 ◽  
Author(s):  
ANDREW MYKYTSEY ◽  
PRADEEP MAHESHWARI ◽  
GAURAV DHAR ◽  
MANSOUR RAZMINIA ◽  
TERRY ZHEUTLIN ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Ischemic Cardiomyopathy ◽  
Biventricular Pacing

Abstract 16187: Validation of Novel Algorithm to Automate Detection of Fractionated Electrograms During Ventricular Tachycardia (VT) Ablation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Pouria Alipour ◽  
Yaariv Khaykin ◽  
Meysam Pirbaglou ◽  
Paul Ritvo ◽  
Gal Hayam ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Area Under The Curve ◽  
High Sensitivity ◽  
Left Ventricular ◽  
Target Area ◽  
Automate Detection ◽  
Noise Threshold ◽  
Vt Ablation ◽  
Patient At Risk ◽  
Novel Algorithm

Introduction: Ablation of ventricular tachycardia (VT) substrate in patient at risk for VT in the setting of ischemic heart disease is a technically challenging procedure. We thought to evaluate a novel algorithm used to automatically identify target electrograms. Methods: 16 consecutive patients (70±10 years of age, 90% male, 34±18% LV EF) had 20 ablations for ischemic VT using CARTO 3 mapping system over 2 years. Left ventricular (LV) substrate was mapped during right ventricular (RV) apical stimulation. Navistar Thermocool 3.5 mm irrigated tip catheters were used in all patients. A novel algorithm counting the number of electrogram deflections (NOD) crossing the 0.05mV noise threshold and duration of time from first to last such deflection during the window of interest (total fractionation time, TFT) was applied to all acquired maps after ablation was complete. Snapshots of 200 electrograms representing the high and low end of TFT and NOD values were presented to a group of 8 electrophysiologists experienced in VT ablation who were asked to select electrograms they would target for substrate ablation. The diagnostic accuracy of TFT and NOD values was then analysed. Results: Across the range of TFT values (0.0-281.0 ms), a cut-off value of 49.0 ms (81.6% sensitivity, 57% specificity) was established as an optimal indicator of an ablation target. Area under the curve for TFT was 0.675 (95% CI: 0.59-0.75, p=0.001). For NOD values (0.0-70.0 deflections), a cut off of 4.5 deflections (88.0% Sensitivity, 57 % specificity) was established as an optimal indicator of an ablation target. The area under the curve for NOD yielded an area of 0.75 (95% CI: 0.68-0.82, P=0.001). For TFT-NOD product as a variable, a cut-off value of 64 (91.0% Sensitivity, 52.4 % specificity) an optimal indicator of an ablation target. The Area under the curve for NOD and TFT multiple was 0.72 (95% CI: 0.65-0.80, P=0.001). Conclusion: A novel algorithm may be able to automatically classify LV substrate during mapping and ablation of ischemic VT with high sensitivity and acceptable specificity.

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