From the Research
ECG Changes in Hypercalcemia
The following ECG changes have been observed in patients with hypercalcemia:
- Shortening of the QT interval, specifically the QoT, QaT, and QeT intervals, which are measured from the beginning of the QRS complex to the origin, apex, and end of the T wave, respectively 1, 2, 3
- Prolongation of the PR and QRS intervals at very high serum calcium levels 2
- T wave flattening or inversion 2, 3
- Appearance of a J wave at the end of the QRS complex at very high serum calcium levels 2
- ST elevation, which can mimic acute myocardial infarction 2, 4, 3
Specific ECG Intervals
The following ECG intervals have been studied in relation to hypercalcemia:
- QoTc interval: shortened in hypercalcemic patients, with a sensitivity of 83% and specificity of 100% in predicting high serum calcium levels 1
- QaTc interval: shortened in hypercalcemic patients, with a sensitivity of 57% and specificity of 100% in predicting high serum calcium levels 1
- QeTc interval: shortened in hypercalcemic patients, with a sensitivity of 39% and specificity of 89% in predicting high serum calcium levels 1
Clinical Implications
Hypercalcemia can cause ECG changes that mimic acute myocardial infarction, emphasizing the importance of considering hypercalcemia as a differential diagnosis in patients with ST-segment elevation and QT shortening 2, 4, 3