Rapid Onset and Resolution of Cardiogenic Shock in a Patient With Pheochromocytoma

A pheochromocytoma is a rare catecholamine-secreting tumor that can be familial or arise sporadically. Its typical presenting features include symptoms of headache, palpitations, and diaphoresis occurring in paroxysms. The classic presenting sign is episodic hypertension, although only in 59% of cases, have evidence of hypertension at diagnosis.1 There have been a few case reports of patients with pheochromocytoma presenting with cardiogenic shock2–10 but none with both cardiogenic shock and ventricular tachycardia. Additionally, we are not aware of any case reports of such a rapid decline and then improvement in ejection fraction (EF) as demonstrated in this case. We report the unusual presentation of a patient who developed cardiogenic shock within seconds during the course of a single transthoracic echocardiogram (TTE) only to recover minutes later without intervention. A 69-year-old man with type II diabetes mellitus presented with a complaint of a single syncopal episode to an outside institution. The patient was found to have multiple ventricular ectopic beats and frequent runs of nonsustained ventricular tachycardia. The patient was a past smoker but had no personal history of cardiovascular disease or other additional significant medical history. Family history was significant for hypertension and diabetes. The patient was taking metformin and glipizide for his type II diabetes mellitus. The physical examination was significant for orthostasis and an S4 gallop. The remainder of the physical examination was unremarkable. Initial laboratory results demonstrated mildly elevated troponin levels at 0.55 ng/mL and acute renal failure with a serum creatinine of 1.9 mg/dL. The patient’s hemoglobin concentration was 18.5 g/dL. There were no other significant laboratory abnormalities. The patient was subsequently transferred to our center for urgent cardiac catheterization for suspected acute coronary syndrome. On transfer, the patient’s heart rate was elevated and his blood pressure (BP) was noted to be labile: alternating between severe hypotension and hypertension (Table I). On arrival, an initial electrocardiogram was obtained which showed ventricular ectopics and left ventricular hypertrophy (Figure 1). On telemetry, the patient continued to have multiple episodes of nonsustained ventricular tachycardia (Figure 2). An urgent TTE was performed to assess for regional wall motion abnormalities and to a pericardial effusion that might explain the reason for shock. The initial EF based on the subcostal, short-axis, and parasternal long-axis views was 50% to 55% (Figure 3A and Figure 3B). During the study the EF unexpectedly declined to 5% to 10% (Figure 3C and Figure 3D) at which time the patient’s BP dropped to 68/34 mm Hg and the patient became unresponsive. Fluid resuscitation was initiated and the patient was taken emergently to the cardiac catheterization laboratory. 12-Lead electrocardiogram showing multiple ventricular ectopics, nonsustained ventricular tachycardia, and left ventricular hypertrophy by voltage criteria. Telemetry strips showing nonsustained ventricular tachycardia and premature ventricular contractions. Transthoracic echocardiogram showing left ventricular wall thickening during the initial part of the study in the subcostal short-axis view at end-diastole (A) and end-systole (B). The initial ejection fraction (EF) was about 50% to 55%. Seconds later the parasternal short-axis view at end-diastole (C) and end-systole (D) showed an EF of 5% to 10%. The parasternal long-axis view (not shown) confirmed the difference in left ventricular EF. Note the relatively small left ventricular volumes on (A) and (B). After placement of a right femoral artery sheath, the patient’s intraarterial BP was found to be 62/38 mm Hg. A second left femoral artery sheath was placed for an intraaortic balloon pump (IABP), but the patient’s intraarterial BP suddenly increased to 241/136 mm Hg 7 minutes after the initial intraarterial BP measurement. The left ventricular end-diastolic pressure was 0 mm Hg. A left ventriculogram was obtained in the right anterior oblique and left anterior oblique projection with the multipurpose catheter and showed an EF of 60%. Coronary angiography demonstrated luminal irregularities and mild proximal coronary calcification in the left and right coronary artery without any evidence of obstructive coronary artery disease. Because of the patient’s labile BP, a pheochromocytoma or paraganglioma was suspected and serum fractionated catecholamines and metanephrines were drawn immediately at the end of the procedure (Table II). Following the cardiac catheterization, cardiac troponin levels peaked at 1.46 ng/mL without significant creatine kinase MB fraction elevation. A computed tomography scan was obtained, which revealed a heterogeneous, enhancing, right adrenal mass measuring 10.3 cm by 6.9 cm. 24-Hour urinary metanephrines and normetanephrines were measured 2 days later and were elevated at >25,000 and 14,147 μ/d respectively. An iodine-131-meta-iodobenzylguanidine (MIBG) scan was obtained, which did not suggest MIBG avid metastatic disease. The patient was administered intravenous fluids given evidence of volume depletion and was initiated on phenoxybenzamine. Eventually, the IABP was weaned and removed. Labetalol was added for additional BP control. The patient underwent open right adrenalectomy revealing the mass shown in Figure 4,which was confirmed to be a pheochromocytoma. Cut gross specimen showing a tan-colored mass weighing 298 g and measuring 10.0 × 7.0 × 6.0 cm. This case reinforces that a pheochromocytoma can present in unusual ways. Hypertension is not always present, and patients may present with hypotension due to cardiogenic shock or hypovolemic shock. The BP may also rapidly alternate, as in our case, between hypotension and hypertension.11,12 While not true in our case, pure epinephrine-secreting tumors can present with episodic hypotension due to stimulation of β2- receptors resulting in vasodilatation.13 Pheochromocytomas presenting with cardiogenic shock have been reported but the decline in EF has never been documented to occur within a matter of seconds during the course of a single TTE. It is believed that the acute decline in EF in our case was the result of massive catecholamine release caused by abdominal manipulation by the echocardiographer during obtainment of the subcostal views. The catecholamines then had immediate deleterious effects on cardiac function and subsequent hemodynamics similar to a stress-induced or catecholamine-induced cardiomyopathy. It is not clear why the EF improved within minutes despite high measured levels of catecholamines.