I think that it is too simple just to use "my heart pounded." I prefer something a little bit more elaborated. What sentence can I use besides from "my heart pounded?" Maybe you can include your own paragraph, or borrow a paragraph from a published work. I plan to use these answers for inspiration in my own novel.
I asked the AI that I've been building for some descriptions of "my heart pounded" and got these suggestions. Hopefully it's helpful!
- Your heart pounds like a drum in your chest, fast and hot in anticipation of something — anything.
- It had triggered the primal flight reaction or something like it: a massive flood of adrenaline that shot through me like a drug and made me feel deeply alive.
- I felt like I was on fire and like I might spontaneously combust at any moment, like someone had set a slow and steady match beneath my center, deep in the pit of my stomach.
- My heart beats as it pumps my blood through my veins. The blood rushes to the tips of my fingers, the pulse coming in hot waves that cause everything else to pulse.
- My heart pounds with each breath, my heart pounds like a hummingbird’s wings
- The booming was furious and incessant. It was my heart, which seemed to swell into a mallet and swing against my rib cage, a drum full of dirt that might burst at any moment.
Other than synonyms (e.g. thump instead of pound or gallop instead of race), you could also use comparison, e.g. "My heart was beating so loudly I thought they would hear it for sure." Also, instead of describing the heart beat, you could also describe the blood flow. For example, it could be rushing in their ears, or their pulse could pound in their wrists or neck instead.
Or you could describe the feeling of excitement or fear in entirely different terms:
Maybe the character's mouth is going dry, and they're finding themselves swallowing nervously. If they're having trouble breathing (too shallow, too fast), their vision might go woozy. Maybe sweat is dripping into their eyes, or they're wiping their sweaty hands on their shirt. Maybe their knees are shaking, or they're otherwise starting to feel a bit wobbly. Maybe every little creak suddenly sounds a thousand times louder. Maybe time is crawling to a slow-down.