Abstract
INTRODUCTION: Thyrotoxicosis is known to cause a high-output cardiac state and atrial fibrillation, but progression to biventricular dysfunction and secondary pulmonary hypertension is rare. Early diagnosis and definitive treatment of root cause are critical to prevent systemic complications, Herein we report an unusual case where prompt treatment reversed the cardiopulmonary effects of thyrotoxicosis. CLINICAL CASE: A 42-year-old male presented with symptoms of thyrotoxicosis. His thyroid function tests demonstrated hyperthyroidism and anti-thyroglobulin antibodies were also significantly elevated. The patient developed atrial fibrillation and was later found to have biventricular dysfunction on echocardiogram. Patient was initially managed with antithyroid medication but was poorly compliant and later became refractory to treatment, and declined radioactive iodine therapy. Over time, he developed signs suggestive of pulmonary hypertension. Due to progression of his symptoms and treatment resistance, patient eventually underwent total thyroidectomy. Postoperatively, thyrotoxicosis resolved. Echo findings showed significant Improvements in Pulmonary HTN and Pulmonary Artery Systolic Pressure (PASP) Improvement from 37 mmHg + RAP (high probability of PH) to 22 mmHg (low probability of PH). CONCLUSION: This case illustrates an unusual but reversible complication of thyrotoxicosis, where delayed and refractory treatment led to cardiac decompensation and secondary pulmonary hypertension. Definitive management through thyroidectomy led to marked clinical improvement. Clinicians should be aware of this potential complication and consider early definitive therapy in non-compliant or treatment-refractory cases. Diagnosis is based on a detailed history, clinical examination, supplemented by relevant investigations (elevated free T4 and thyroid receptor antibodies, suppressed thyroid stimulating hormone (TSH) and imaging). Mainstay of treatment includes anti-thyroidal medications and if goal not achieved thyroidectomy and regular follow up electrocardiograms.