Tetany and Heart Failure as the Life-Threatening Manifestations of Tropical Sprue: A Case Study of an Uncommon Presentation for an Infrequent Disease

Abstract

Purpose: To describe tropical sprue (TS) as an uncommon cause of hypocalcemic tetany and heart failure Methods: An 83 year-old woman was admitted to the Emergency Department with carpopedal spasm, altered mental status and chronic diarrhea. On admission, she was unconscious. Her vital signs were: BP: 90/70 mmHg, HR: 120/min, RR: 42/min, T: 37.8°C, SatO2: 86%. The thoracic examination was positive for bilateral crackles and S3 in the cardiac auscultation. Neurological findings included rigidity on four limbs, generalized hyperreflexia and no meningeal signs. Results: Laboratory analysis showed Hb: 7.5 mg/dL(MCV: 95 fL), WBC: 13.8x109 and platelets: 254x 109/L. Biochemical studies included Glu: 134 mg/dL, Urea: 34 mg/dL, Cr: 1 mg/dL, Na: 142mmol/L, K: 3.11mmol/L and Cl: 101mmol/L. Tbili: 0.2 mg/dL, ALP: 210 U/L, AST/ALT: 463/153 U/L. The ionic Calcium was severely depleted: 0.52 mmol/L. PTH: 55 pg/mL, 25(OH)vitamin D: < 3 ng/dL, Vitamin B12: 457 pg/mL and Folic acid: 2 ng/dL. Additional blood work including aTTP and TP were normal and HIV, HepB/C and HTLV-1 serology were negative. Potential complications of severe hipocalcemia were studied including an EKG that showed prolonged QT interval (0.8 s) and poor R wave progression. Furthermore, extensive ventricular hypokinesia along with an ejection fraction at 45% was noted in the transthoracic echocardiography. Troponins were negative.The chest X- ray revealed cardiomegaly, pulmonary congestion and bilateral interstitial infiltrates. The patient was placed on inotropic therapy and after IV calcium reposition the symptoms of heart failure and the EKG changes reverted. Stool samples were tested for bacteria, fungi and parasites, with negative results. Transglutaminase and Anti-Gliadin antibodies were also negative. Duodenal biopsy showed flattening of the villi with signs of chronic inflammation and intraepithelial lymphocytes. In this case-scenario, the differential diagnosis for this patient included small intestinal bacterial overgrowth (SIBO) and TS. Given the low risk factors for SIBO, empirical treatment for TS was started with folic acid reposition with subsequent improvement of her clinical status in the following weeks. Conclusion: TS is a rare cause of malabsorptive chronic diarrhea described to be more frequent in tropical regions, albeit in South America there is a paucity of reports. Tetany and heart failure as a result of severe hypocalcemia due to TS is an uncommon presentation of this disease.Figure 1Figure 2