We understand that you are seeking prayer for someone special to you who has been diagnosed with Atrial fibrillation. We will pray for his health and address the concerns you've raised, but first, we want to remind you that our prayers should be directed to God the Father in the name of Jesus Christ. It is through Jesus that we have access to God, and it is in His name that we are saved. As it is written in Acts 4:12 WEB:
There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved.
Now, let us pray together for this man's health and your peace of mind:
Dear Heavenly Father,
We come before You in the name of Jesus Christ, lifting up the man who is dear to the one who submitted this request. Lord, You know his health concerns, and we ask that You touch his body and heal his heart. We pray that the Atrial fibrillation would subside, and that his heart would beat normally again. We ask that his upcoming test would show positive results and that any underlying issues would be revealed and addressed.
If this condition is due to stress or dehydration, we pray that You would help him manage his stress levels and remind him to stay hydrated. We ask that You would take away his fear and anxiety, and that You would give him peace.
Lord, we also pray for the one who submitted this request. We ask that You would take away their fear and remind them of Your constant presence. We pray for their safety during travels and that You would guide and protect them.
Father, we ask all these things in the precious name of Jesus Christ, our Lord and Savior. It is in His name that we pray, Amen.
May you both find comfort and peace in God's presence, and may you continue to trust in Him, knowing that He is always with you. Remember the words of Jesus in Matthew 28:20 WEB:
Behold, I am with you always, even to the end of the age. Amen.
We encourage you both to continue in prayer and to seek God's will in all things. If there are any lifestyle changes that need to be made to improve health, we pray that God would provide the wisdom and guidance needed to make those changes. Always remember to turn to God in prayer, knowing that He hears you and that He cares for you.
Also, include the name of Jesus Christ in your prayers, as it is through Him that we have access to God the Father. As it is written in John 14:6 WEB:
Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me.
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
