Conduction defects in mature mice without the Gata6 carboxyl
zinc-finger. (A, B) Surface ECG leads I, II, III. aVR, aVL & aVF along with
intracardiac recordings of the right atrial electrogram (RAE) and His-bundle
electrogram (HBE) from an adult Mlc2vCre-Gata6f/f
(A) and Gata6f/f (B) mouse. Note the PR-interval is
longer (red dashed lines) in the mutant mouse, with no gross defects in overall
QRS-complex morphology or other intervals on the surface ECG leads. The
Mlc2vCre-Gata6f/f mouse has a PR-interval of
57 ms vs. 46 ms for the Gata6f/f mouse. Recordings
from the HBE show atriohisian (AH) interval prolongation (solid blue lines)
without functional Gata6. The
Mlc2v-CreGata6f/f mouse has an AH-interval
of 42 ms vs. 31 ms for the Gata6f/f mouse. P=P-wave;
QRS=QRS-complex; T=T-wave; a=atrial electrogram; v=ventricular electrogram.