Comparing this verse with marginal references, it would seem that in 2 Chronicles 14:3, 2 Chronicles 14:5 the intention and endeavors of the monarch are in the writer’s mind, while here he is speaking of the practice of the people. However earnestly the most pious monarchs sought to root out the high-place worship, they failed of complete success. Compare a similar discrepancy, to be similarly explained, in the history of Jehoshaphat 2 Chronicles 17:6; 2 Chronicles 20:33.
The heart of Asa was perfect all his days - Not that Asa was sinless (see 2 Chronicles 16:2-10, 2 Chronicles 16:12); but that he was free from the sin of idolatry, and continued faithful to Yahweh all his life.