Are there mechanisms in place to distinguish SVT with aberrant conduction from VT on external cardiac monitoring devices? 

Unfortunately, there is no easy answer to this question. Differentiation of aberrancy from ventricular tachycardia can be very difficult, even with high quality 12-lead ECGs. Standard rules can be applied but many features of VT such as precordial R-wave concordance, is not possible. The best idea i...