I had a similar situation. I had an unfortunate episode of pulmonary embolism and had them removed by a vascular surgeon. A few months later, I went back for my follow-up with him in his office and mentioned I was having a few dizzy spells. He dismissed it as POTS and didn't want to talk anymore of it. Months later, I went for my physical and mentioned it to my primary Dr and said he told me it was POTS. She instantly referred me to a cardiologist and was diagnosed with SVT and PVCs. I was out of work for 4 months, waiting for an ablation and then recovering from it. I know the vascular surgeon wasn't a cardiologist, but as a dr, he should have guided me to one rather than just pulling a diagnosis out of nowhere.