Final answer:
The primary treatment for TCA overdose and associated cardiac toxicity is sodium bicarbonate.
Step-by-step explanation:
Tricyclic antidepressant (TCA) overdose can lead to cardiac toxicity. The primary treatment for TCA overdose is sodium bicarbonate, which helps to correct the acidosis caused by the overdose.
Sodium bicarbonate is administered intravenously and it works by increasing the pH of the blood, which can stabilize the heart rhythm and improve cardiac function. It is important to note that sodium bicarbonate does not directly reverse the effects of the TCA overdose, but it can help to prevent life-threatening cardiac arrhythmias.