Mr. Theodore Jeffers is a 73-year-old admitted to the progressive coronary care unit with a diagnosis of atypical chest pain and congestive heart failure. He has a history of acute myocardial infarction, deep vein thrombosis, hypertension, diabetes mellitus, and gouty arthritis. He reports "spasm-like" chest pain over his breastbone and difficulty "catching my breath." His admission data includes the following:
Chest pain rated as a 4 on a scale of 1 to 10; states,"It feels like my heart is clenching like a fist—I am notsure I can call it pain."
BP: 172/100 – 102 – 30
Temperature: 99.2°F
O₂ saturation: 90% on room air
Lungs: fine crackles throughout all lung field
Heart sounds with S3 present
4+ pitting edema, decreased peripheral pulses bilaterally,feet cool to touch
Height: 72 inches; Weight: 231#; BMI: 31.3
As the day progresses, Mr. Jeffers becomes confused. Based on your understanding of oxygenation and perfusion, what is the probable etiology of this change in status?