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. Author manuscript; available in PMC: 2013 Feb 1.
Published in final edited form as: Circ Arrhythm Electrophysiol. 2011 Dec 22;5(1):181–190. doi: 10.1161/CIRCEP.111.967265

Figure 3.

Figure 3

Emergence of RV epicardial EADs, triggered activity and VF in a heart isolated 29 days after MCT injection. In each panel the recordings from top to bottom are: pseudo-ECG, LV and left atrial bipolar electrograms (LV Beg and LA Beg), and the bottom tracing is single cell microelectrode recording from the RV epicardial base. Panel A shows the emergence of an EAD on two consecutive sinus beats (two downward arrows) 28 min after mounting the heart with regular sinus rhythm (SR) at a mean cycle length of 254±18 ms. The EAD associated with the third sinus beat triggers an action potential at a coupling interval of 85 ms (upward arrow) causing a premature ventricular depolarization (PVD) on the pseudo-ECG (arrow). Notice that the emergence of RV epicardial cell EAD is associated with isoelectric interval of the LA Beg, LV Beg and pseudo-ECG recordings indicating absence of electrical activity elsewhere in the heart during the emergence of EADs in the RV. Panel B shows recordings 29 min after tissue mounting (1 min after panel A) with the third sinus beat associated with EAD-mediated triggered activity (upward arrow) causing non-sustained ventricular tachycardia (NSVT) (arrow on pseudo-ECG). Panel C shows recordings made 2 min after panel B showing EAD-mediated triggered activity to cause VT (~18 beats) which then degenerates to irregular pattern signalling the onset of VF. The VF was then terminated by electrical shock (not shown). Panel D shows magnified view of part of the lower 2 recordings of A.