The Full Deal
If you defend as suggested, you score plus 50 (two hearts, two top spades, and a diamond ruff) for 87%; otherwise minus 140 for 43%.
Bonus from Val: After winning the second round of trumps, lead the eight of hearts (making it clear that you don’t want a heart return) to get your ruff. Then, to the next trick, lead the Jack of hearts, in case (unlikely but possible) partner started with AK10 and declarer started with three small (in that alternative layout, you would defeat the contract by two tricks rather than one).
Bonus from Val: Perhaps, as East, you would wonder whether West had started with 1093 of diamonds rather than 103 doubleton. The answer is that if West had 1093 of diamonds, then after seeing declarer win the Ace of diamonds at trick one, West should realize that there is no future in diamonds and should, instead, try to take all of the heart tricks that the defenders may have. So when West continues diamonds, East should be confident that West started with a doubleton and is looking for a ruff. Deal D003.
To explore alternative lines of play and defense, use this link: https://tinyurl.com/4xdrbtm4