Refer to how 3-6 Mafia started out with horrocore rap and normally used uptempo beats and then by 2000 they had became more entrenched in the “Screw” Culture starting with the famous “Sippin on Some Syrup” where songs focus on being slowed and made to be chopped and screwed.
The line before Paul says, Now my heart don’t know what to think. So he’s referring to the counter effects of the yayo and the lean; the yayo having his heart beating fast, as it does, and the lean, slowing his heart rhythm down, as it does. His heart, “don’t know what to think.”
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