FCEM2-0551

A 60 year old male presents to the emergency department complaining of palpitations and a headache. The patient appears distressed and is observed to be trembling and sweating excessively. The patient has no regular medication and no significant medical history. The patient mentions experiencing similar episodes in the past few months, but none as severe as this one. The patient’s vital signs are as follows:

Blood pressure: 212/100 mmHg
Pulse: 98 bpm
Respiration: 16 bpm
Oxygen saturations: 97% on room air

What is the most likely diagnosis?