How to can I make Filename Sequencing with the help of Loops

my intention is to keep the code as simple as possible.Here there are 5 files namely

A_1.CSV, A_2.CSV, A_3.CSV, A_4.CSV, A_5.CSV

The below code retrieves the first row in a CSV file.

Code : head.sh(filename)

awk -F, 'NR==1 {print $0}' A_1.CSV > Header.csv
awk -F, 'NR==1 {print $0}' A_2.CSV >> Header.csv
awk -F, 'NR==1 {print $0}' A_3.CSV >> Header.csv
awk -F, 'NR==1 {print $0}' A_4.CSV >> Header.csv
awk -F, 'NR==1 {print $0}' A_5.CSV >> Header.csv

Question :

In the above code, only the filename changes from A_1 to A_2 and so on. How can I make the code simple with loops.

Example :

 for (i=1;i<=5;i++)
      {
       A_[i].CSV >> Header.csv
      }

I don't know how to do this logic with shell scripting.

UPDATED CODE :

Files in the Directory : /home/thiyagu/Desktop/

for file in 'A_*.CSV'
do
awk -F, 'NR==1 {print $0}' $file >> Newheader.csv
done