Brief Answer:
Ecg, holter helps in diagnosis and treatment by medicine and ablation

Detailed Answer:
Hello,
Its a cardiac arrhythmia in which heart rate suddenly goes up and also suddenly decreases. Blood pressure falls during these episodes and one has dizziness, fainting, blackouts, sometimes syncope.
Usually ecg done during the episode will diagnose the atrial flutter, however if done in between the episodes, its normal. You may need 24 hour holter monitoring if episodes are occurring daily. This will identify the rhythm and diagnose it if it recurs in 24 hrs. If none of the above is successful then last option is of electrophysiological studies which is invasive test similar to angiography which can diagnose and radiofrequency ablation can be done simultaneously to treat the arrhythmia permanently in most of the cases. However, one is not willing for this, can be kept on medicines like Beta blocker like Metoprolol, diltiazem which will control the heart rate. Also, patients will be kept on blood thinners like acitrom or warfarin or other like dabigatran to prevent blood clot formation in atria and stroke.
Hope this helps you and get back if you have any doubts.

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