The article discusses the rare but serious complications of cardiac arrest following the injection of clinical doses of potent local anesthetics such as etidocaine and bupivacaine. Despite the belief that prompt oxygenation and blood pressure support can prevent such events, these drugs can cause sudden cardiovascular collapse, including ventricular fibrillation, tachycardia, cardiac asystole, and complete heart block, often immediately after rapid injection. Resuscitation is often difficult, requiring prolonged cardiac massage. The article highlights several case reports where cardiac arrest occurred after intravascular injection of these drugs, emphasizing the need for caution and the potential for underreporting. The relative toxicity of these drugs is higher when administered intravenously compared to injection sites due to their high lipid solubility. The true incidence of this phenomenon and the effectiveness of various resuscitation methods, especially for cardiac depression, require further research.The article discusses the rare but serious complications of cardiac arrest following the injection of clinical doses of potent local anesthetics such as etidocaine and bupivacaine. Despite the belief that prompt oxygenation and blood pressure support can prevent such events, these drugs can cause sudden cardiovascular collapse, including ventricular fibrillation, tachycardia, cardiac asystole, and complete heart block, often immediately after rapid injection. Resuscitation is often difficult, requiring prolonged cardiac massage. The article highlights several case reports where cardiac arrest occurred after intravascular injection of these drugs, emphasizing the need for caution and the potential for underreporting. The relative toxicity of these drugs is higher when administered intravenously compared to injection sites due to their high lipid solubility. The true incidence of this phenomenon and the effectiveness of various resuscitation methods, especially for cardiac depression, require further research.