Final answer:
The CNA should focus on accurately weighing the elderly patient and reporting any significant weight changes to detect early signs of heart failure.
Step-by-step explanation:
To detect early signs of congestive heart failure in an elderly client, it would be most appropriate for the certified nursing attendant (CNA) to accurately weigh the patient and report any significant changes. This is because rapid weight gain may indicate fluid retention, which is a common symptom of heart failure. Instead of observing electrocardiogram readings or monitoring vital signs every 15 minutes, which are actions typically performed by licensed nurses, the CNA should focus on assisting with tasks within their scope of practice. Additionally, aiding the patient with ambulation is important but may not directly indicate heart failure signs as effectively as monitoring weight changes.