surely, certainly

with a startled heart

to be startled, receive a shock / to skip a beat

feeling, sense / air, gas / air, nature, disposition, sense / spirit, mood / inclination, will, mood, urge

feel like; have a feeling that

sensing something that isn't there: one's imagination; part of one's imagination

circuit

to be concerned about; to be interested in; to be bothered by; to have a problem with

(idiomatic) Alternative form of 気が気でない

(idiomatic) very anxious, very worried, feeling uneasy; can't help but be worried