Elaine Caulder, a 56-year-old widow who lives with her sister in a small upstairs apartment noticed increasing difficulty making it up the stairs over the past two months. In addition to this change, she has noticed more difficulty sleeping at night due to problems breathing while lying in a recumbent position, and in the last week, she has had to sleep in a reclining chair in the living room. When she came to the clinic, her appearance showed obvious fatigue, moist rales were heard upon auscultation of the lungs, and her pulse rate was 106 per minute and irregular. She was moderately cyanotic, and had pitting edema in both ankles. Chest x-ray revealed pulmonary edema and a moderately enlarged heart. The diagnosis was congestive heart failure upon her admission, and she was placed on a low sodium diet, diuretics, and potassium supplement. Why is Mrs. Caulder experiencing mild tachycardia? There was hypoxia to the myocardial cells, excitatory impulses are being transmitted to the SA node, there has been node damage from myocardial damage, there has been a depletion of potassium, and/or her heart has enlarged.
Please explain why each “symptom” could or could not be causing the mild tachycardia.