palpitation|palpitations

演讲前他感到胸口强烈的心悸。

He experienced a strong ___palpitation in his chest before the speech.

每次面试前我都会感到心跳加速。

I always get ___palpitations before job interviews.

听到坏消息时，她感到一阵心悸。

She felt ___palpitations when she heard the bad news.