I am not certain about what is causing your symptoms. My first thought is that patients with heart failure are often more short of breath lying down than sitting or standing. A check by your cardiologist would resolve that issue. I assume that by “heart flutter” you mean atrial flutter, not just a fluttering feeling in your chest. If you had successful ablation of the AV node, then the atria (top portion of your heart) should not be conducting to the ventricles (bottom chambers), whether you have atrial fibrillation or atrial flutter. If there is conduction, then the atrial flutter can be ablated also. If my comments do not answer your questions, find out more about your condition from your doctor and write in again.

Ablation Helps Flutter, Too The Saturday Evening Post