Meaning: The boy was scared and his heart was pounding.
Choice of Words: Heart, beat, fast, with, fear are all nouns that describe the boy's emotions. "Fast" is an adverb that tells us how the heart beat.
Alternative Expressions
My heart is pounding with terror.
Meaning: This means that you are feeling very scared or horrified and your heart is beating very loudly because of it.
Choice of Words:Heart is the organ that pumps blood throughout the body. Pounding means to beat very loudly. With means together with something else. Terror is a feeling of extreme fear or horror. When you put them together, "My heart is pounding with terror" means that your heart is beating very loudly because you are feeling extremely scared or horrified.
My chest is thumping like a drum with dread.
Meaning: This means that you are feeling very scared or worried and your chest is beating or pounding like a drum because of it.
Choice of Words:Chest is the part of the body that contains the heart and lungs. Thumping means to beat or pound. Like means similar to. A drum is a musical instrument that is played by hitting it with sticks. With means together with something else. Dread is a feeling of great fear or worry. When you put them together, "My chest is thumping like a drum with dread" means that your chest is beating or pounding like a drum because you are feeling great fear or worry.