MIT-BIT arrhythmia database follows AAMI standards. It has samples of 360 sampling frequency so it can detect heart beats of 180 Hz because of Nyquist frequency.
I have noted that this frequency cannot give good enough resolution for showing the cardiac physiology, for instance, inside QRS-complex.
My friend mentioned me about Holter 360 register, but I cannot find any discussion about it in PubMed, it is probably used only in one hospital of my country.
Is there any publicly available ECG databases with better sampling frequency than 360 Hz?