Ishan Malhotra

Unpredictable Nature of Tolvaptan in Treatment of Hypervolemic Hyponatremia: Case Review on Role of Vaptans

Hyponatremia is one of the most commonly encountered electrolyte abnormalities occurring in up to 22% of hospitalized patients. Hyponatremia usually reflects excess water retention relative to sodium rather than sodium deficiency. Volume status and serum osmolality are essential to determine etiology. Treatment depends on several factors, including the cause, overall volume status of the patient, severity of hyponatremic symptoms, and duration of hyponatremia at presentation. Vasopressin antagonists like tolvaptan seem promising for the treatment of euvolemic and hypervolemic hyponatremia in heart failure. Low sodium concentrations cause cerebral edema, but the overly rapid sodium correction can also lead to iatrogenic cerebral osmotic demyelination syndrome. Demyelination may occur days after sodium correction or initial neurologic recovery from hyponatremia. The following case report analyzes the role of vasopressin antagonists in the treatment of hyponatremia and the need for daily dosing of tolvaptan and the monitoring of serum sodium levels to avoid rapid overcorrection which can result in osmotic demyelination syndrome (ODS).

1619: SEPSIS-INDUCED ISOLATED RIGHT VENTRICULAR STRESS CARDIOMYOPATHY MASQUERADING AS PULMONARY EMBOLISM.

Learning Objectives: Stress cardiomyopathy (SC) is a type of transient non-ischemic acute cardiomyopathy which is characterized by wall motion abnormalities of the heart in which intense physical or emotional stress can lead to sudden and severe heart muscle weakness. We present a rare case of sepsis/ respiratory distress induced stress cardiomyopathy with isolated right ventricle (RV) involvement, which was initially thought to be secondary to pulmonary embolism. Methods: A 84 year old woman with past medical history of chronic obstructive pulmonary disease (COPD) presented to the emergency room with shortness of breath and lethargy. The patient was started on anticoagulation for suspected pulmonary embolism (PE) and was admitted to the intensive care unit for hemodynamic instability requiring vasopressor support and respiratory failure. Echocardiogram (ECHO) showed severely decreased RV function, RV ballooning and normal left ventricular (LV) wall motion. Computed tomography angiography showed small chronic sub-segmental PE in the right upper lobe, which was not significant enough to cause the degree of hemodynamic instability in this patient. ECHO done two weeks prior to admission showed normal RV function. Electrocardiogram showed new V2-V4 “T” wave inversions with rising serum troponin levels. Coronary angiography showed clean coronary arteries. Cultures confirmed the diagnosis of urinary tract infection leading to sepsis and with appropriate treatment of sepsis and COPD exacerbation, patient showed clinical improvement and improved RV function on repeat ECHO. Results: SC most commonly involves the apical segment of the left ventricle. Isolated involvement of the RV has rarely been described in the literature, apart from few sporadic cases. To the best of our knowledge, this is the first case of isolated of RV stress cardiomyopathy masquerading as massive PE on initial presentation. This case makes it imperative to further study this new, emerging variant of SC in the future since it can be easily misdiagnosed as massive PE potentially leading to inappropriate thrombolytic therapy.