I believe it is better to examine the words and the original languages of Scripture and allow Scripture to define the words used in it. In this article regarding The Greatest Commandment, we find that our "heart" is the center of our being and that part of us which makes decisions. It is that part of us which chooses.
When G-d gave the commandment to wear tzitzit it was because of the sinfulness (i.e. the error in choosing) of our hearts:
"It shall be tzitzit for you to look at and remember all the commandments of the LORD, so as to do them and not follow after your own heart and your own eyes, after which you played the harlot, so that you may remember to do all My commandments and be holy to your God. [emphasis mine] (Numbers 15:39-40)
G-d desires for us to be holy but our eyes and our heart get in the way.
When we follow our hearts we might just be fulfilling the words of Proverbs:
There is a way which seems right to a man, But its end is the way of death. (Proverbs 14:12, 16:25)
Consider also this passage about the heart:
For forty years I loathed that generation, And said they are a people who err in their heart, And they do not know My ways. (Psalm 95:10) [speaking of the generation that wandered in the wilderness]
Perhaps I should be clearer in my point... we should not follow our heart as is suggested by the personalfinancebythebook.com article. Instead we should seek after G-d's heart.
"The LORD has sought out for Himself a man after His own heart, and the LORD has appointed him as ruler over His people..." (1 Samuel 13:14)
The man described here was none other than King David.
The prophet Ezekiel promises that Isra'el will receive a new heart... perhaps one like King David:
Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh. (Ezekiel 36:26)
Notice that this promise is only to Isra'el. It is not to the people of Germany, nor the people of Spain, and not even the people of the United States are given this promise. Only Isra'el. This is yet another reason why Paul repeatedly tells us that Gentiles (upon their belief in the Messiah Yeshua) become part of Isra'el. Why? Because G-d has only made promises to them... not the nations of the world.
Once Isra'el has this new heart, what does G-d do with it? A special, great, and wonderous thing. He impresses Himself upon it via His Torah.
I will put My Torah within them and on their heart I will write it; and I will be their God, and they shall be My people. (Jeremiah 31:33)
G-d writes His Torah upon the heart of flesh that He has given to Isra'el. Why? To conform them to the image of His Son (Romans 8:29).
That is the goal... to make believers more Christ-like. Consider again the words of the Psalmist:
Who may ascend into the hill of the LORD? And who may stand in His holy place? He who has clean hands and a pure heart, Who has not lifted up his soul to falsehood And has not sworn deceitfully. (Psalm 24:3-4)
Should we follow our hearts? No.
We should follow G-d's heart and seek His ways.
In all your ways acknowledge Him, And He will make your paths straight. (Proverbs 3:6)
But seek first His kingdom and His righteousness, and all these things will be added to you. (Matthew 6:33)
If we desire to follow after a heart... let it be the heart of our risen Lord and Savior.
Now to the King eternal, immortal, invisible, the only God, be honor and glory forever and ever. Amen. (1 Timothy 1:17)