A 50-year-old male construction worker presents with shortne…
A 50-year-old male construction worker presents with shortness of breath, anxiety, and palpitations that have been present for 3 hours. He denies chest pain. His blood pressure is 141/78 mmHg, pulse is 140/min, and respirations are 18/min. An EKG demonstrates tachycardia, no discernible p waves and irregularly irregular distribution of the QRS complexes. Which of the following is the most likely diagnosis?