Electrolyte abnormalities can be life-threatening, and their management depends on the speed of onset of the electrolyte’s derangement and the patient's existing comorbidities. Electrolyte imbalances can affect the electrical activity of the heart and can be seen on an Electrocardiogram (ECG). The specific ECG changes will depend on the specific electrolyte imbalance. For example, a high potassium level (hyperkalemia) can cause tall, peaked T-waves and a widened QRS complex. Low potassium levels (hypokalemia) can cause flattened or inverted T-waves. A high calcium level (hypercalcemia) can cause a shortened QT interval and a prolonged PR interval. Low calcium levels (hypocalcemia) can cause a prolonged QT interval. A high sodium level (hypernatremia) can cause a prolonged QT interval, while a low sodium level (hyponatremia) can cause a shortened QT interval. It's important to note that electrolyte imbalances can also cause other ECG changes, such as heart rhythm disturbances, and these changes can be nonspecific, so an ECG is not the only test to confirm the electrolyte disturbance. It's also important to note that electrolyte imbalances can lead to arrhythmias, such as bradycardia, tachycardia, atrial fibrillation, and ventricular fibrillation. These arrhythmias can also be seen on an ECG.
