A 10-year-old girl presented emergently with the chief symptom of a “fast heartbeat” that awakened her from sleep. On examination, her heart rate varied from 120 to 170 beats/min, and her blood pressure was 160/90 mmHg. Her medical history was notable for schizophrenia, and her medications included quetiapine, escitalopram, valproic acid, and clonidine. Electrocardiography revealed acute junctional tachycardia (heart rate, 202 beats/min) with no ST-segment changes.
The patient was admitted to the hospital and underwent extensive testing that showed normal thyroid function and elevated plasma catecholamine levels: norepinephrine, 9,166 pg/mL (normal, 150–400 pg/mL); and normetanephrine, 39.3 nmol/L (normal, ≤0.89 nmol/L). The epinephrine level of 25 pg/mL was within normal limits. Pheochromocytoma was suspected, and abdominal magnetic resonance imaging (MRI) revealed a para-aortic mass with involvement of the L4 vertebral body. In addition, 123I-metaiodobenzylguanidine scintigraphy was performed, and the uptake of the contrast medium was consistent with the MRI findings.
Routine echocardiographic evaluation showed moderately depressed myocardial function (left ventricular [LV] ejection fraction, 0.32), and SSI revealed diffuse LV myocardial dysfunction, particularly in the basal myocardial segments (). The global peak systolic longitudinal strain was −9% (normal, greater than −18%).
Fig. 1 Depicted in a bulls-eye format, 2-dimensional echocardiographic speckle strain imaging shows the peak systolic strain of longitudinal myocardial fibers shortly after the patient's hospital admission. Several areas show different degrees of systolic (more ...)
For the next 2 weeks, the patient was given verapamil for tachycardia and enalapril, clonidine, and phenoxybenzamine for hypertension. After the tachycardia was controlled and the patient's blood pressure had fallen to 90/50 mmHg, the paraganglioma was resected; however, the neuroendocrine tissue around vertebra L4 was not treated during this intervention. Global ventricular function improved postoperatively (LV ejection fraction, 0.55). The global peak systolic longitudinal strain was −19%, with improvements in previous areas of localized regional wall motion ().
Fig. 2 Speckle strain imaging after partial tumor resection shows overall improvement in peak systolic strain; some basal segments show regional wall-motion abnormalities. ANT = anterior; ANT_SEPT = anteroseptal; ApLAX = apical long axis; AVC (more ...)
The patient was weaned from the cardiac medications and was discharged from the hospital 2 weeks after surgery. A few weeks later, echocardiography showed improved cardiac function and LV ejection fraction. Normetanephrine levels were still slightly elevated (1.12 nmol/L). On SSI analysis, LV myocardial function was substantially improved; however, persistent areas of basal myocardial-segment dysfunction were noted (global peak systolic longitudinal strain, −18.5%) ().
Fig. 3 Speckle strain imaging a few weeks postoperatively shows improvement in the overall pattern of deformation, although the septal and anterolateral basal segments have decreased peak systolic strain values. ANT = anterior; ANT_SEPT = anteroseptal; (more ...)