HOCM - testing for possible surgical intervention

6 years ago, I had a stress echo with pre exercise peak gradients of 19 mm hg at rest and 31mm hg with valsalva. After exercise peak gradient of 123 and mean gradient of 60mm hg. i was started on verapamil (I have asthma so no beta blockers) with fairly good symptom relief....Gradually over the years I have required more and more verapamil.. 240mg ER BID right now and lasix a couple times a week because I get 3+ edema.
Right now I am 6 weeks post Takot Subo episode (which REALLY relieved my symptoms for a short whileLOL)
My doctor has me scheduled for a cardiac MRA to truly evaluate the anatomy of my HOCM. I am very interested in septal myectomy if I have the type of septum that would be resected. Long story, 2 short questions:
1)Wouldn't the MRA give a more accurate picture of the anatomy if I was off verapamil for several days before?
2) What are the septal measurements that make one a good surgical candidate? my regular echo on all this verapamil doesn't look bad  20-50 mg hg with valsalva, septum 1.41 during diastole 2.41 during systole.But I am sick of the symptoms and the side effects of the verapamil...and I don't want to start Norpace if I can get away with it........Thanks, from an old ICU nurse who knows just enough to ask wierd questions. ;-)

[CCFheartMD10]

No, you do not need to be off verapamil for the MRI. Verapamil doesn't shrink your septum, but (partially) relieves the obstruction.
Generally, indications for myectomy include shortness of breath that is refractory to medications, intolerance to medications, an episode of heart failure, syncope (fainting) or near-syncope, and a blood pressure drop of or failure to increase during exercise, and very functional capacity as measured by a stress echo. Symptoms are the main reason for people to undergo a myectomy. There are no hard and fast rules for who should and should not undergo the procedure based on echo or MRI measurements. The appearance of the mitral valve is also important in selecting patients and planning the procedure.
The most important point in considering whether a myectomy is suitable for you or not is to review your testing with a cardiologist and surgeon who are experienced in this operation.  If you would like to make an appointment at the Cleveland Clinic Heart and Vascular Institute, please call 1-800-CCF-CARE or inquire online at https://my.clevelandclinic.org/heart/default.aspx