IPA: /ˌkɑːrdiəˈlɒdʒɪk/
KK: /kɑrdiˈɑlədʒɪk/
Relating to the study and treatment of heart diseases and conditions.
The cardiological examination revealed that the patient had a minor heart issue.
Cardiological → It is formed from "cardio-" (from Greek "kardia", meaning heart) and "-logical" (from Greek "logia", meaning study or science). The word "cardiological" refers to the study or science of the heart.
Think of 'kardia' meaning heart, and 'logia' meaning study — so cardiological is all about the study of the heart.