Reread what i posted and realize how hard this is to describe without pictures...
For an example that might help illustrate..
I look at an ekg and i see 4 pvcs.
2 pvc heartbeats are pointy on top
2 pvc heartbeats are round on top
Both of the pointy pvc's are identical
Both of the round pvcs are identical.
I go inside the heart and i shock the left side of the heart.
When i shock i see a pointy pvc show up on my ekg. I put a picture of the natural pointy pvc on top of a picture of the pointy pvc that appeared after i shocked.
They match! So i burn there.
Next i try shocking the right side.. And lo and behold! A round pvc appears.. And they match so i burn!
I had 2 pvc's when i started.. 1 pointy and 1 round.
Each of the 2 pvc's occured twice! So what i saw was 4 pvc heartbeats... 2 from each side of the heart.
I paced 2 places in the heart, and matched them up.
Now i have successfully burnt both pvc's i saw.
You absolutely need to see the pvcs to do the ablation..
You dont even necessarily need alot of them, but you need to see them.
Basically, if youve ever looked at an ekg youll notice the pvcs tend to look similar... Each pvc had its own special 'shape'.
The reason the shape of the pvc is what it is has alot to do with the specific spot in which its located.
When they do pvc ablation they basically take a "picture" of each of your pvcs. The ablator is then used to pace (deliver a small electrical shock) to different parts of your heart.
Those electrical shocks produce a waveform with a special "shape" as well.
Basically the shape of the pvc or paced stimulation is like a google maps pin..
When the shape of the paced waveform matches the shape of your pvc, the operator knows that his ablation catheter is positioned directly above the part of the heart where the pvc is coming from.
Without any pvcs to take a picture of at the start of the procedure, they dont have that google maps or gps pin to let them know when they are in the right location to burn.
Additionally most labs use 3d mapping systems... These systems are basically really big fancy computers that are able to calculate the approximate location of your pvc's. With these systems the more data it had to work with the more accurate it can be.
In summary at least 1 pvc is needed to perform the ablation, and the more pvc's you have the quicker the procedure will be as the 3d mapping system can help narrow down the precise location.
Given your story its possible that either the staff couldnt get you to have any pvc's at all, or the amount of pvc's you were having was insufficient for them to complete the ablation before your condition deteriorated.