Your husband is a 'complex' case, and the SVT is paroxysmal, or intermittent. An EP can sometimes elicit the arrhythmia by 'challenging' the heart using chemicals. It works....often....but it also doesn't work for all hearts. He can't ablate tissues willy-nilly and hope for the best because that can be both counterproductive AND risky for the patient. We all want only the necessary tissues ablated....thanks very much.

I am not qualified medically, so this is just my thinking: the Sotalol seems to work okay, or well enough. Maybe so well that the EP cannot do his job. Also, Sotalol is more potent than metoprolol, for example, because it is a Class III anti-arrhythmic drug and is a 'non-selective beta blocker.' Metoprolol is selective. I think your EP wants more of a fair fight. He wants your husband off Sotalol before long, and that is likely to bring on the detectable locations when he does the mapping and tries to find the right places to apply the ablative energy....whatever kind he intends to use or knows is best for your husband's condition.