Can innapropriate sinus tachycardia lead to atrial fibrillation got to go to hospital monday for ECG my heart rhythm gone from normal to abnormal?

Not usually. This would be a bit odd. Usually fibrillation is the result of age, drinking, and diseases which exhaust or stretch out the atria. Inappropriate sinus tach usually doesn't directly result in afib. When it went to "abnormal" are you sure that was to fib? Did they get an ekg? Could well be flutter too, which can occasionally be mistaken for fib.
No. Inappropriate sinus tachycardia does not cause atrial fibrillation, though the 2 may coexist. If you did have a procedure such as ablation, you could temporarily have atrial arrhythmias including a. Fib. In the first 2-3 months.