This is the 10047th most frequent Spanish word.
cardíaco
Related to the heart.
The word "cardíaco" here is used as an adjective describing "paro" (arrest) to signify it relates to the heart.
El paciente sufrió un paro cardíaco.
The patient suffered a cardiac arrest.
In this sentence, "cardíaco" functions as an adjective modifying "sistema" (system) to indicate it pertains to the heart.
Los ejercicios cardiovasculares ayudan a fortalecer el sistema cardíaco.
Cardiovascular exercises help to strengthen the cardiac system.
Here, "cardíaco" is an adjective describing "monitoreo" (monitoring), emphasizing its relation to heart health or function.