This Patient died in 15 minutes after coming to Emergency Room

Patient present with severe chest pain to the ED. ECG was done immediately and is attached below. can u please interpret the ECG.

A 54-year-old lady presented with reeling of head for one day. She has history of syncope yesterday. She gives similar history in the past. She was sitting comfortably. Her pulse was not palpable. BP not recordable. Her heart rate was around 200 beats per minute on auscultation. Chest was clear. Diagnosis and management.

35 YRS OLD MALE WORKING AS A CHEF C/O PALPITATIONS SINCE LAST 3 MONTHS. KINDLY GIVE YOUR VALUABLE OPINION

45 year female with severe palpitation, irritability, some anxiety, nausea vomiting, mild left st chest pain , pulse 175/mit , BP 110/70 , RBS 100mg/dl , spo2 98%, chest xray normal 2D echo normal , D/D ?

36 yr old female with history of recurrent episodic palpitation for last 6 yrs, echo- normal