Discussion
This case illustrated an unusual ECG pattern of diffuse J-point elevation which is non-cardiac in aetiology. The authors would like to specifically mention that there is no ST-segment upsloping, but rather ‘J-point elevation’ with an elevated cardiac troponin level. Such an ECG pattern can be alarming, as it may suggest early changes of acute myocardial infarction. Of note, her deterioration during presentation was without symptoms typical of myocardial infarction and there was a resolution of ST-segment changes following electrolyte correction and hydration. These findings strengthen the proposition that electrolyte imbalance secondary to gastrointestinal loss and the newly diagnosed hypoparathyroidism was the cause of the global ST-segment elevation. ECG changes of global ST- segment elevation is well recognized in hyperkalemia. However, reported cases associated with hypokalemia are rare. A pseudoinfarction ECG pattern as seen in hyperkalemia was noted previously in a patient with severe hypokalemia undergoing correction, and was postulated to be associated with rapid changes in intracellular/extracellular [K+] ratio6. Hypocalcemia has been shown to simulate ECG patterns of myocardial injury with subsequent investigations showing no evidence of infarction8-9 and it has also been suspected to provoke coronary vasospasm9. Dehydration, severe hypotension, congestive heart failure, coronary vasospasm, myocardial bridging, and hypertensive emergencies have all been linked to provoking conditions that can cause a mismatch in myocardial oxygen supply (type II myocardial infarction). An elevated cardiac troponin has been found in these situations10. Taken together, these facts fit well in the case of our patient but the exact mechanism and contribution of these factors to the ECG manifestation remain unknown. According to earlier case studies, metabolic acidosis associated with DKA may also result in an elevation in ST-segment2-4. However, our patient’s pH, serum bicarbonate, or other serum electrolytes did not notice any noteworthy alterations when the ECG was normalized.
To date, several authors have reported cases of hypoparathyroidism diagnosed many years after surgery. This phenomenon of delayed onset hypoparathyroidism has been postulated to be associated with scar formation as well as progressive atrophy of parathyroid glands. We report this rare case with the aim of creating awareness about this potential complication in post thyroidectomy patients. This case adds to the literature as well the association of hypokalemia and hypocalcemia with pseudo-ischemic electrographic changes that clinicians should be aware of.