Why is This Patient Dizzy, Weak, and Tachycardic?

​BY ANGEL BERMUDEZ, MD, & WESLEY EILBERT, MDAn 81-year-old woman with a history of metastatic lung cancer, hypertension, and COPD presented with dizziness that she described as lightheadedness, generalized weakness, and mild shortness of breath for three days. She also reported recent anorexia and a sensation of impending loss of consciousness.She was thin and appeared ill, and she was unable to stand unsupported. She was afebrile with a heart rate of 101 bpm and a blood pressure of 92/55 mm Hg.Her initial ECG is shown. What else could this be if not ST-elevation myocardial infarction?Our patient was found to have a serum calcium of 19.6 mg/dL and a troponin I within the normal range. ECG changes with hypercalcemia include prolongation of the PR interval and the QRS interval and shortening of the QT interval. (Ann Noninvasive Electrocardiol. 2016;21[1]:30.)Hypercalcemia is an uncommon though well-documented cause of ST elevation that may mimic acute MI. (Am J Emerg Med. 2017;35[7]:1033.e3.) ST elevations from hypercalcemia are most commonly seen in the anterior precordial leads, often have a “scooped” appearance, and typically are not followed by distinct T waves. (J Electrocardiol. 2007;40[1]:60.) The exact mechanism of ST elevation caused by hypercalcemia is not known, but some hypothesize that it is simply an artifact due to shortening of the interval between the S wave and the end of the T wave. As the T wave moves closer to the QRS complex, the ST s...
Source: The Case Files - Category: Emergency Medicine Tags: Blog Posts Source Type: research