3-Dimensional ventricular electrical activation pattern assessed from a novel high-frequency electrocardiographic imaging technique: principles and clinical importance

Abstract

The study introduces and validates a novel high-frequency (100–400 Hz bandwidth, 2 kHz sampling frequency) electrocardiographic imaging (HFECGI) technique that measures intramural ventricular electrical activation. Ex-vivo experiments and clinical measurements were employed. Ex-vivo, two pig hearts were suspended in a human-torso shaped tank using surface tank electrodes, epicardial electrode sock, and plunge electrodes. We compared conventional epicardial electrocardiographic imaging (ECGI) with intramural activation by HFECGI and verified with sock and plunge electrodes. Clinical importance of HFECGI measurements was performed on 14 patients with variable conduction abnormalities. From 3 × 4 needle and 108 sock electrodes, 256 torso or 184 body surface electrodes records, transmural activation times, sock epicardial activation times, ECGI-derived activation times, and high-frequency activation times were computed. The ex-vivo transmural measurements showed that HFECGI measures intramural electrical activation, and ECGI-HFECGI activation times differences indicate endo-to-epi or epi-to-endo conduction direction. HFECGI-derived volumetric dyssynchrony was significantly lower than epicardial ECGI dyssynchrony. HFECGI dyssynchrony was able to distinguish between intraventricular conduction disturbance and bundle branch block patients.

Ventricular Dyssynchrony and Pacing-induced Cardiomyopathy in Patients with Pacemakers, the Utility of Ultra-high-frequency ECG and Other Dyssynchrony Assessment Tools

“…UHF-ECG displays the sequence of ventricular activation using an analysis of the ultra-high frequency components of ventricular myocyte action potentials in perimyocardial tissue. [ 50 , 51 ]…”

“…UHF-ECG displays the sequence of ventricular activation using an analysis of the ultra-high frequency components of ventricular myocyte action potentials in perimyocardial tissue. 50,51 The ventricular activation sequence under standard chest leads (V1-V6 or V1-V8 configuration) is displayed in depolarisation maps, usually in 1-3 minutes, making the method suitable for clinical practice. The broad-band QRS complex is constructed as the average of the 16 normalised median amplitude envelopes of the 16 frequency bands (150-1000 Hz) and displayed as a coloured map for chest leads.…”

Ultra-High-Frequency ECG in Cardiac Pacing and Cardiac Resynchronization Therapy: From Technical Concept to Clinical Application

“…In this experimental setup, two Langendorff-perfused pig hearts were suspended in a human torso-shaped tank. UHF-ECG imaging was performed with surface tank electrodes and validated with epicardial sock and plunge electrodes in the heart [ 50 ].…”