Figure 3. Normal cardiac function after loss of TBX5 in the VCS.
(A and B) Cardiac function, assessed by M-mode echocardiography, of Tbx5fl/fl controls (A) and Tbx5minKCreERT2 littermates (B) administered tamoxifen at 6–7 weeks of age and studied 4–5 weeks later in sinus rhythm. No functional difference between mutant and control mice was detected. (C) A Tbx5minKCreERT2 animal with episodic spontaneous ventricular tachycardia demonstrated rapid recovery of ventricular function during sinus beats (asterisks) that followed tachycardic episodes.