BACKGROUND: Imaging myocardial activation from noninvasive body surface potentials promises to aid in both cardiovascular research and clinical medicine. OBJECTIVE: To investigate the ability of a noninvasive 3-dimensional cardiac electrical imaging technique for characterizing the activation patterns of dynamically changing ventricular arrhythmias during drug-induced QT prolongation in rabbits. METHODS: Simultaneous body surface potential mapping and 3-dimensional intracardiac mapping were performed in a closed-chest condition in 8 rabbits. Data analysis was performed on premature ventricular complexes, couplets, and torsades de pointes (TdP) induced during intravenous administration of clofilium and phenylephrine with combinations of various infusion rates. RESULTS: The drug infusion led to a significant increase in the QT interval (from 175 ± 7 to 274 ± 31 ms) and rate-corrected QT interval (from 183 ± 5 to 262 ± 21 ms) during the first dose cycle. All the ectopic beats initiated by a focal activation pattern. The initial beat of TdPs arose at the focal site, whereas the subsequent beats were due to focal activity from different sites or 2 competing focal sites. The imaged results captured the dynamic shift of activation patterns and were in good correlation with the simultaneous measurements, with a correlation coefficient of 0.65 ± 0.02 averaged over 111 ectopic beats. Sites of initial activation were localized to be ~5 mm from the directly measured initiation sites. CONCLUSIONS: The 3-dimensional cardiac electrical imaging technique could localize the origin of activation and image activation sequence of TdP during QT prolongation induced by clofilium and phenylephrine in rabbits. It offers the potential to noninvasively investigate the proarrhythmic effects of drug infusion and assess the mechanisms of arrhythmias on a beat-to-beat basis.
BACKGROUND: Imaging myocardial activation from noninvasive body surface potentials promises to aid in both cardiovascular research and clinical medicine. OBJECTIVE: To investigate the ability of a noninvasive 3-dimensional cardiac electrical imaging technique for characterizing the activation patterns of dynamically changing ventricular arrhythmias during drug-induced QT prolongation in rabbits. METHODS: Simultaneous body surface potential mapping and 3-dimensional intracardiac mapping were performed in a closed-chest condition in 8 rabbits. Data analysis was performed on premature ventricular complexes, couplets, and torsades de pointes (TdP) induced during intravenous administration of clofilium and phenylephrine with combinations of various infusion rates. RESULTS: The drug infusion led to a significant increase in the QT interval (from 175 ± 7 to 274 ± 31 ms) and rate-corrected QT interval (from 183 ± 5 to 262 ± 21 ms) during the first dose cycle. All the ectopic beats initiated by a focal activation pattern. The initial beat of TdPs arose at the focal site, whereas the subsequent beats were due to focal activity from different sites or 2 competing focal sites. The imaged results captured the dynamic shift of activation patterns and were in good correlation with the simultaneous measurements, with a correlation coefficient of 0.65 ± 0.02 averaged over 111 ectopic beats. Sites of initial activation were localized to be ~5 mm from the directly measured initiation sites. CONCLUSIONS: The 3-dimensional cardiac electrical imaging technique could localize the origin of activation and image activation sequence of TdP during QT prolongation induced by clofilium and phenylephrine in rabbits. It offers the potential to noninvasively investigate the proarrhythmic effects of drug infusion and assess the mechanisms of arrhythmias on a beat-to-beat basis.
Authors: A W Maurits van der Graaf; Pranav Bhagirath; Hemanth Ramanna; Vincent J H M van Driel; Jacques de Hooge; Natasja M S de Groot; Marco J W Götte Journal: Ann Noninvasive Electrocardiol Date: 2014-02-19 Impact factor: 1.468
Authors: Chengzong Han; Steven M Pogwizd; Long Yu; Zhaoye Zhou; Cheryl R Killingsworth; Bin He Journal: Am J Physiol Heart Circ Physiol Date: 2014-11-21 Impact factor: 4.733
Authors: Ashok J Shah; Han S Lim; Seigo Yamashita; Stephan Zellerhoff; Benjamin Berte; Saagar Mahida; Darren Hooks; Nora Aljefairi; Nicolas Derval; Arnaud Denis; Frederic Sacher; Pierre Jais; Remi Dubois; Meleze Hocini; Michel Haissaguerre Journal: J Atr Fibrillation Date: 2014-10-31