Cardiac ultrasound is among the many beneficial applications of point-of-care (POC) ultrasound in the ED. This modality can prove extremely beneficial in evaluating the critically ill patient. For example, POC cardiac ultrasound not only permits the emergency physician (EP) to diagnose a pericardial effusion and cardiac tamponade, but also perform a pericardiocentesis.1 The EP can also employ beside ultrasound to estimate an ejection fraction (EF) almost as well as cardiology services,2 look for signs of right-heart strain in patients with pulmonary embolism (PE),3 and guide fluid management in patients who have septic shock.4 In addition to only taking a few minutes to perform, POC cardiac ultrasound can also drastically change the course of management in some patients. Our case illustrates the use of POC ultrasound to diagnose Takotsubo cardiomyopathy in a 64-year-old patient and guide management when she became unstable prior to cardiac catheterization.
Case
A 64-year-old white woman with a medical history of diabetes, obesity, and nephrolithiasis presented to the ED with chest pain and shortness of breath, which she stated had begun earlier in the day. The patient’s chest pain did not intensify upon exertion, but the shortness of breath worsened when she was in the supine position.
Three months prior, the patient had also presented to our ED with chest pain. Evaluation during that visit included a negative stress echocardiogram with an EF of 55%. At this second visit, an electrocardiogram (ECG) showed new T-wave inversions in the anterior, lateral, and inferior leads. Vital signs at presentation were: blood pressure, 107/63 mm Hg; heart rate, 100 beats/min; respiratory rate, 18 breaths/min; and temperature, 97.9°F. Oxygen saturation was 97% on room air when patient was sitting upright, but decreased to 90% when she was supine. A chest X-ray showed left basilar atelectasis with a trace effusion. Laboratory evaluation was remarkable for the following: troponin I, 2.99 ng/mL; D-dimer, 294 ng/mL; and brain natriuretic peptide, 559 pg/mL.
Given the patient’s vital signs and positive troponin I level, a computed tomography (CT) scan was ordered to assess for a PE. This was done despite the patient’s negative D-dimer results, as it was felt that she was not low-risk for PE. At the same time the CT scan was ordered, a POC cardiac ultrasound was performed to assess for signs of right heart strain.
Based on the ultrasound findings and a normal EF 3 months prior, there was concern for Takotsubo cardiomyopathy. The patient was further questioned as to the events surrounding the onset of her chest pain. She informed the EP the pain started when she learned that she might be evicted from her home.
The CT scan was negative for PE. The consulting cardiologist was informed of the results of the ultrasound findings, and the patient was given aspirin, heparin, morphine, and furosemide, and was admitted to the cardiac progressive unit. She was also initially given morphine for pain management, but due to intolerance, she was switched to nitroglycerin.
During the first evening of her inpatient stay, the patient experienced acute changes in her chest pain that resulted in activating the rapid response team. Secondary to the information gathered in the ED, the patient was managed conservatively and was evaluated by a physician extender who repeated laboratory studies, provided supplemental potassium and magnesium, and ordered another ECG in consultation with the cardiologist (who was caring for the patient via telephone). In the morning, the patient continued to have chest pain, and a repeat ECG showed worsening of previous T-wave inversions. Based on these findings, the cardiologist ordered cardiac catheterization.
On hospital day 2, the cardiologist performed another echocardiogram, which confirmed the low EF of 20% with severe global hypokinesis with sparing of the basal segments. Cardiac catheterization showed no significant disease (20% lesion in the mid-left anterior descending artery) with the left ventriculogram showing an EF of 10%, cardiac output of 3.7, and cardiac index of 1.8, confirming the diagnosis of Takotsubo cardiomyopathy. The patient remained in the hospital for a total of 8 days while awaiting a life vest; however, a repeat echocardiogram on hospital day 8 showed an EF of 55%.