From Longman Dictionary of Contemporary Englisha broken hearta broken heartSAD/UNHAPPYa feeling of extreme sadness, especially because someone you love has died or left you I reckon she died of a broken heart. → broken
Examples from the Corpus
a broken heart• Harald died three months later, I believe of a broken heart.• It was part sadness, like a broken heart.• It was the universal panacea for a broken heart.• Sindham dies and then Ana dies of a broken heart.• This was after David had split up with Hermione and was nursing a broken heart.• He has to find a way to heal a broken heart and help hold his family together.• According to legend, anyone who ever fired the weapon died of a broken heart or cardiac arrest.• The system caused many a broken heart over the generations. 