In a case of tricyclic antidepressant overdose, which electrolyte imbalance may be indicated on an ECG?

In the context of tricyclic antidepressant (TCA) overdose, hyperkalemia is commonly associated with cardiovascular complications that may be reflected on an ECG. TCAs can cause a wide variety of arrhythmias and can depress myocardial conductivity, which can lead to various ECG changes. One of the notable alterations seen in TCA toxicity is the potential for hyperkalemia to occur, which manifests as a peaked T wave, widening of the QRS interval, and, in severe cases, can lead to a sine-wave pattern on the ECG.

Patients with TCA overdose may also experience metabolic effects that could disrupt electrolyte balance, particularly affecting potassium levels. The mechanism includes the inhibition of sodium channels causing a disturbance in cardiac depolarization and repolarization, potentially leading to the release of potassium from cells. Therefore, recognizing hyperkalemia on an ECG assists in managing the potential complications of TCA toxicity effectively.

The other electrolyte disturbances listed, such as hyponatremia, hypocalcemia, or hypermagnesemia, do not typically present with the same degree of urgency or the recognized ECG changes attributed to TCA overdose. While they may occur in other clinical scenarios, they are not characteristic of TCA overdose and won't have the specific ECG