DOI: https://doi.org/10.36347/sjmcr.2026.v14i06.060

Pages: 1584-1587

Background: Hyperthyroidism exerts profound cardiovascular effects through positive inotropic and chronotropic actions. The 'thyroid heart' encompassing sinus tachycardia, atrial fibrillation (AF), and high-output heart failure requires early multidisciplinary management. Methods: Retrospective, observational, single-centre study (STROBE-compliant) of 150 adults with confirmed hyperthyroidism and at least one cardiac manifestation, January 2020 – December 2023. Demographics, aetiology, ECG, echocardiographic, and therapeutic data collected. Multivariable logistic regression identified predictors of AF non-reversion to sinus rhythm after euthyroidism. Results: Cardiac complications documented in 117 patients (78%). Mean age 45.2±12.5 years; 71% female; Graves' disease leading aetiology (72%). Sinus tachycardia present in 60%; AF in 28% (n=42), mean ventricular rate 128±22 bpm. Echocardiography revealed hyperdynamic left ventricle (LVEF 68±5%) in 65% and diastolic dysfunction in 45%. After euthyroidism, spontaneous sinus rhythm reversion occurred in 64% of AF patients. Independent predictors of AF non-reversion: AF duration >3 months (OR 3.8; 95%CI 1.6–9.2; p=0.003), age >55 years (OR 2.9; 95%CI 1.2–7.1; p=0.018), and left atrial enlargement (LAVi >34 mL/m²; OR 2.4; 95% CI 1.1–5.3; p=0.031). Conclusions: The thyroid heart is dominated by tachyarrhythmias and high-output heart failure. Spontaneous AF reversion after euthyroidism occurs in 64%, guided by duration, age, and atrial enlargement. Systematic ECG and echocardiographic evaluation at diagnosis and urgent euthyroidism restoration are essential.