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

• Published in: PloS one Vol. 16; no. 7; p. e0254683
• Main Authors: Masjedi, Mustafa, Jungen, Christiane, Kuklik, Pawel, Alken, Fares-Alexander, Kahle, Ann-Kathrin, Klatt, Niklas, Scherschel, Katharina, Lorenz, Jürgen, Meyer, Christian
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14-07-2021; Public Library of Science (PLoS)
• Subjects: Ablation; Aged; Algorithms; Analysis; Annotations; Automation; Biology and Life Sciences; Cardiac arrhythmia; Cardiology; Cardiomyopathy; Cardiovascular diseases; Catheter Ablation - methods; Catheters; Consortia; Coronary artery disease; Diagnosis; Electrocardiography - methods; Electrodes; Electrophysiologic Techniques, Cardiac - methods; Engineering and Technology; Female; Heart diseases; Humans; Imaging, Three-Dimensional - methods; Intensive care; Ischemia; Low noise; Male; Mathematical models; Medical instruments; Medicine and Health Sciences; Middle Aged; Myocardial ischemia; Myocardial Ischemia - diagnosis; Myocardial Ischemia - physiopathology; Myocardium; Physical Sciences; Physiology; Process parameters; Research and Analysis Methods; Segments; Signal processing; Substrates; Tachycardia; Tachycardia, Ventricular - diagnosis; Tachycardia, Ventricular - physiopathology; Tachycardia, Ventricular - surgery; Target recognition; Three dimensional models; Two dimensional models; Ventricle; Ventricular tachycardia; Visualization; Germany; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0254683

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.
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.
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.
The novel algorithm allows rapid visualization of prolonged EGM durations. This may facilitate more objective characterization of arrhythmogenic substrate in patients with ischemic cardiomyopathy.