1) Does structural heart disease eg. valvular diseases cause ventricular tachycardia?

2) Is it true that someone with Premature Ventricular Contraction (PVC) is in a high risk to develop VTach?

3) How does nonsustained ventricular tachycardia being treated in the patient with prior structural heart disease?

4) I was informed that beta-blockers are safe, and they are the first choice unless contraindicated. But as we know, beta-blockers block the function of epinephrine and couldn't be used by patients with severe allergies. So, what kind of drug/s could be use as substitution?