This is a great study showing that actually ondansetron protects heart by lowering noradrenaline and protecting against
hypertrophy.
5-HT3 receptor antagonists protect against pressure overload-induced cardiac hypertrophy in murine - ScienceDirect
hypertrophy.
5-HT3 receptor antagonists protect against pressure overload-induced cardiac hypertrophy in murine - ScienceDirect