Declension table of hṛdayamantra

Neuter	Singular	Dual	Plural
Nominative	hṛdayamantram	hṛdayamantre	hṛdayamantrāṇi
Vocative	hṛdayamantra	hṛdayamantre	hṛdayamantrāṇi
Accusative	hṛdayamantram	hṛdayamantre	hṛdayamantrāṇi
Instrumental	hṛdayamantreṇa	hṛdayamantrābhyām	hṛdayamantraiḥ
Dative	hṛdayamantrāya	hṛdayamantrābhyām	hṛdayamantrebhyaḥ
Ablative	hṛdayamantrāt	hṛdayamantrābhyām	hṛdayamantrebhyaḥ
Genitive	hṛdayamantrasya	hṛdayamantrayoḥ	hṛdayamantrāṇām
Locative	hṛdayamantre	hṛdayamantrayoḥ	hṛdayamantreṣu

Compound hṛdayamantra -

Adverb -hṛdayamantram -hṛdayamantrāt