Mr. Y is а 59 yо mаn brоught tо the hospitаl via ambulance with acute dyspnea. He complains of progressive SOB with exertion, dry cough, weight gain, and stiffness in hands and feet. He denies any chest pain. Jugular vein distention noted. 2+ LE pitting edema noted. He was diagnosed with CHF. PMH: HTN, appendectomy. He denies cardiac history and does not smoke. He states he drinks a few beers per week. SH: He lives with his wife in a 2 story house. He is retired from an auto assembly plant. He reports heavy yardwork and housework are getting difficult. He takes daily walks with his wife but has cut back the distance this past month due to fatigue. Vital signs: BP 151/95, HR 105, RR 26, and on 4L O2 nc to maintain SpO2> 93% Lab values: RBC normal, WBC normal, Troponin I 0.1 (↑), HGB 10 g/dL Prior to treatment, the physical therapist assistant sees the following ECG on the telemetry monitor: Mr. Y's heart rhythm on ECG is: