Most cardiotoxic local anesthetic: (A) Procaine, (B) Bupivacaine, (C) Cocaine, (D) Lidocaine
Answer is B. Bupivacaine is the most cardiotoxic LA (Ropivacaine is a newer bupivacaine congenial with less cardiotoxicity).(Refer: stoelting's pharmacology and physiology in anaesthetic practice, 5th edition, pg no.294)