[Cardiac action of crystalline tetrodotoxin. 4. Effect on the relationship between cardiac stimulation frequency and contraction of the heart].
D000818:Animals; D004558:Electric Stimulation; D004594:Electrophysiology; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D013779:Tetrodotoxin / Q000494:pharmacology*
D013779:Tetrodotoxin