AimsUse of a non-invasive electrocardiographic mapping system may aid in rapid diagnosis of atrial or ventricular arrhythmias or the detection of ventricular dyssynchrony. The aim of the present study was to validate the mapping accuracy of a novel non-invasive epi- and endocardial electrophysiology system (NEEES).Methods and resultsPatients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were merged with the data obtained from the NEEES during pacing from implanted pacemaker leads or pacing from endocardial sites using an electroanatomical mapping system (CARTO 3, Biosense Webster). The earliest activation as denoted on the NEEES three-dimensional heart model was compared with the true anatomic location of the tip of the pacemaker lead or the annotated pacing site on the CARTO 3 map. Twenty-nine patients [mean age: 62 ± 11 years, 6/29 (11%) female, 21/29 (72%) with ischaemic cardiomyopathy] were enrolled into the pacemaker verification group. The mean distance from the non-invasively predicted pacing site to the anatomic reference site was 10.8 ± 5.4 mm for the right atrium, 7.7 ± 5.8 mm for the right ventricle, and 7.9 ± 5.7 mm for the left ventricle activated via the coronary sinus lead. Five patients [mean age 65 ± 4 years, 2 (33%) females] underwent CARTO 3 verification study. The mean distance between non-invasively reconstructed pacing site and the reference pacing site was 7.4 ± 2.7 mm for the right atrium, 6.9 ± 2.3 mm for the left atrium, 6.5 ± 2.1 mm for the right ventricle, and 6.4 ± 2.2 for the left ventricle, respectively.ConclusionThe novel NEEES was able to correctly identify the site of pacing from various endo- and epicardial sites with high accuracy.

AimsThe aim of the present study was to estimate the accuracy of a novel non-invasive epicardial and endocardial electrophysiology system (NEEES) for mapping ectopic ventricular depolarizations.Methods and resultsThe study enrolled 20 patients with monomorphic premature ventricular contractions (PVCs) or ventricular tachycardia (VT). All patients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were semi-automatically processed by the NEEES to reconstruct a realistic 3D model of the heart and torso. In the electrophysiology laboratory, body-surface electrodes were connected to the NEEES followed by unipolar EKG recordings during episodes of PVC/VT. The body-surface EKG data were processed by the NEEES using its inverse-problem solution software in combination with anatomical data from the heart and torso. The earliest site of activation as denoted on the NEEES 3D heart model was compared with the PVC/VT origin using a 3D electroanatomical mapping system. The site of successful catheter ablation served as final confirmation. A total of 21 PVC/VT morphologies were analysed and ablated. The chamber of interest was correctly diagnosed non-invasively in 20 of 21 (95%) PVC/VT cases. In 18 of the 21 (86%) cases, the correct ventricular segment was diagnosed. Catheter ablation resulted in acute success in 19 of the 20 (95%) patients, whereas 1 patient underwent successful surgical ablation. During 6 months of follow-up, 19 of the 20 (95%) patients were free from recurrence off antiarrhythmic drugs.ConclusionThe NEEES accurately identified the site of PVC/VT origin. Knowledge of the potential site of the PVC/VT origin may aid the physician in planning a successful ablation strategy.

Personalised cardiac models were built from the computed tomography imaging data for two patients with implanted cardiac resynchronisation therapy devices. The cardiac models comprised a biventricular model of myocardial electrophysiology coupled with a model of the torso to simulate the body surface potential map. The models were verified against electrocardiogams (ECG) recorded in the patients from 240 leads on the body surface under left ventricular pacing. The simulated ECG demonstrated a significant sensitivity to the myocardial anisotropy and location of the pacing electrode tip in the models. An apicobasal cellular heterogeneity was shown to be less significant for the ECG pattern at the pacedventricle activation than that showed earlier by Keller and co-authors (2012) for the normal activation sequence.

The objectives of this study were to evaluate the accuracy of personalized numerical simulations of the electrical activity in human ventricles by comparing simulated electrocardiograms (ECGs) with real patients’ ECGs and analyzing the sensitivity of the model output to variations in the model parameters. We used standard 12-lead ECGs and up to 224 unipolar body-surface ECGs to record three patients with cardiac resynchronization therapy devices and three patients with focal ventricular tachycardia. Patient-tailored geometrical models of the ventricles, atria, large vessels, liver, and spine were created using computed tomography data. Ten cases of focal ventricular activation were simulated using the bidomain model and the TNNP 2006 cellular model. The population-based values of electrical conductivities and other model parameters were used for accuracy analysis, and their variations were used for sensitivity analysis. The mean correlation coefficient between the simulated and real ECGs varied significantly (from r = 0.29 to r = 0.86) among the simulated cases. A strong mean correlation (r > 0.7) was found in eight of the ten model cases. The accuracy of the ECG simulation varied widely in the same patient depending on the localization of the excitation origin. The sensitivity analysis revealed that variations in the anisotropy ratio, blood conductivity, and cellular apicobasal heterogeneity had the strongest influence on transmembrane potential, while variation in lung conductivity had the greatest influence on body-surface ECGs. Futhermore, the anisotropy ratio predominantly affected the latest activation time and repolarization time dispersion, while the cellular apicobasal heterogeneity mainly affected the dispersion of action potential duration, and variation in lung conductivity mainly led to changes in the amplitudes of ECGs and cardiac electrograms. We also found that the effects of certain parameter variations had specific regional patterns on the cardiac and body surfaces. These observations are useful for further developing personalized cardiac models.

With the participation: All-Russian Scientific Society of Specialists in Clinical Electrophysiology, Arrhythmology and Pacing, Russian Association of Cardiovascular SurgeonsEndorsed by: Research and Practical Council of the Ministry of Health of the Russian Federation

Introduction: The present study compared invasive activation and phase mapping to noninvasive phase mapping in patients with cavotricuspid isthmus (CTI)-dependent atrial flutter (AFl) using a novel noninvasive epicardial and endocardial electrophysiology system (NEEES). Methods: Four patients with CTI-dependent AFl underwent simultaneous invasive and noninvasive mapping using an electroanatomical mapping system and the NEEES. A mapping catheter aligned along the tricuspid valve region provided data on local activation times analysing unipolar and bipolar electrograms (EGs). Invasive and noninvasive EGs were processed using the same phase mapping algorithm. Results: Activation times obtained invasively and noninvasively from phase-processed unipolar EGs demonstrated close correlation with activation times obtained from invasive bipolar EGs. Noninvasively reconstructed phase maps accurately delineated the activation sequence of CTI-dependent AFl. Conclusion: Noninvasive phase mapping can accurately delineate the activation pattern of CTIdependent AFl and may be useful in other types of macro-reentrant tachycardias.

Чумарная Т. В.*-1 к.б.н., с. н.с. лаборатории математической физиологии, 2 н.с. лаборатории математического моделирования в физиологии и медицине, Соловьева О. Э.-1 д.ф.-м.н., зав. лабораторией математической физиологии, 2 зав. лабораторией математического моделирования в физиологии и медицине, Алуева Ю. С.-врач отделения функциональной диагностики, Михайлов С. П.-к. м.н., зав. отделением хирургического лечения нарушений ритма сердца и электрокардиостимуляции, Остерн О. В.-врач отделения хирургического лечения нарушений ритма сердца и электрокардиостимуляции, Кочмашева В. В.-зав. отделением функциональной диагностики, Сопов О. В.-к. м.н., врач отделения хирургического лечения тахиаримий, Ревишвили А. Ш.-академик РАН, профессор, зав. отделением, Мархасин В. С.-1 д.б.н., профессор, член-корр. РАН, г. н.с. лаборатории, 2 в.н.с. лаборатории].

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