An Unusual Case of Obstructive Shock

A 54-year-old man presented in profound obstructive shock. Investigations revealed a right atrial mass causing severe right ventricular inflow obstruction and compromised cardiac output. The patient was treated with emergency balloon catheter intervention to relieve the obstruction, with resulting hemodynamic stability. The pathology report later returned a positive result for diffuse large B-cell lymphoma. (Level of Difficulty: Intermediate.)

On arrival, he was profoundly hemodynamically unstable. He required 3 vasopressors to maintain a blood pressure of 75/58 mm Hg. He was bradycardic, with a heart rate of 47 beats/min in sinus rhythm. On physical examination, he was sedated and ventilated.
He was mottled, with thready peripheral pulses and cool extremities. His neck and face were markedly discolored and swollen, with distended veins. His heart sounds were barely audible on precordial auscultation, with no murmurs or extra heart sounds heard. His lungs were clear to auscultation bilaterally.
His abdomen was slightly distended but nonperitonitic. He had a Foley catheter inserted but had not produced urine for several hours. He was hypoxemic, with an arterial PO 2 of 75 mm Hg despite ventilation with 100% inhaled fraction of inspired oxygen. His serum lactate level was 21.2 mmol/L, with

LEARNING OBJECTIVES
To be able to create a differential diagnosis for the patient presenting with obstructive shock. To understand the role of hemodynamics in the management of obstructive shock related to an intracardiac mass.
an arterial pH of 6.85 and a serum bicarbonate level of 4 mmol/L.

PAST MEDICAL HISTORY
Two weeks before his presentation, he had received a diagnosis of pericarditis during a visit to a peripheral emergency department and was started on colchicine and ibuprofen.
His past medical history was otherwise significant only for cigarette smoking, with no previous home medications. He had no known allergies or illicit drug use.

DIFFERENTIAL DIAGNOSIS
The patient's clinical examination and biochemical We then performed a right-sided heart catheterization for hemodynamic assessment by navigating around the obstructive mass and into the pulmonary artery, and obtained pressure tracings in each chamber. We observed the superior vena cava (SVC) pressure to be markedly elevated, with a gradient of 11 mm Hg over the right atrial (RA) pressure.
Furthermore, the RA pressure was 33 mm Hg higher than the RV diastolic pressure.

MANAGEMENT
At this time, we believed that the patient required urgent intervention to relieve his obstructive shock, given his hemodynamic instability and high likelihood of imminent death. Surgical consultation was performed by telephone, and the patient was thought to be too unstable for any surgical intervention. We therefore opted for a novel percutaneous approach.
With the hemodynamic information that we had obtained, as well as the location of the mass seen on angiography, we identified 2 locations to target for balloon intervention: the SVC-RA junction and the TV annulus. Although we knew that this procedure carried a relatively high risk of serious complications, we believed that the potential benefits vastly out-

FOLLOW-UP
Following multidisciplinary case rounds, we concluded that tumor debulking with chemotherapy would carry less risk than surgical debulking and was likely to be effective, given the chemotherapyresponsive nature of DLBCL. The patient was therefore transferred to an intensive care unit at a regional cancer center, and the malignant hematology consultant began treatment that evening with cyclophosphamide, dexamethasone, and rituximab. Unfortunately, 7 days following admission to hospital, the patient went into rapid refractory circulatory

FUNDING SUPPORT AND AUTHOR DISCLOSURES
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.