Abstract
Abstract
Background
Thyroid storm (TS) is a rare but potentially life-threatening sequelae of untreated or undertreated hyperthyroidism. While TS frequently causes high-output heart failure, low-output heart failure related to dilated cardiomyopathy (DCM) is extremely rare. Tachycardia is a common clinical presentation of TS, and β1-selective blockers are the first-line agents for treating TS-associated tachycardia. However, given that β-blockers have negative chronotropic and negative inotropic effects, amiodarone may be safe and effective for the treatment of TS-induced tachyarrhythmia in patients with moderate to severe heart failure. While long-term amiodarone administration causes hypothyroidism, or less frequently, hyperthyroidism, little is known about the effects of short-term amiodarone administration on thyroid function.
Case presentation
A 31-year-old healthy woman presented with worsening dyspnoea. She was tachycardic with multifocal atrial tachycardia (MAT) of 184 beats/min, confirmed by electrocardiogram. Echocardiographic findings were consistent with DCM, with an ejection fraction of 20%. Thus, she was initially diagnosed with acute heart failure due to DCM with coexistent MAT. Tachycardia persisted despite cardioversion attempts and treatment with multiple anti-arrhythmic drugs. Consequently, she rapidly progressed to cardiogenic shock and respiratory decompensation, which required intubation and an intra-aortic balloon pump support. Moreover, the undiagnosed Graves' disease, lack of suspicion, and postponed analysis of thyroid function tests led to a delayed diagnosis of TS. Amiodarone, which was initiated for MAT, unexpectedly ameliorated thyrotoxicosis, resulting in a euthyroid state and the patient’s significantly improved condition and cardiac function. She was discharged on day 40. Finally, she underwent total thyroidectomy; thyroid pathology was consisting with Graves' disease. Her postoperative course was uneventful.
Conclusions
Herein, we describe a case of delayed diagnosis of dilated thyrotoxic cardiomyopathy with coexistent MAT. The patient required intensive care due to the catastrophic sequelae and was successfully treated with amiodarone. This is the first case report of TS-associated MAT and highlights the clinical importance of high suspicion of TS in de novo heart failure with any tachyarrhythmia or DCM of unknown etiology and the potential effects of short-term amiodarone administration in the treatment of TS.
Publisher
Springer Science and Business Media LLC
Subject
Cardiology and Cardiovascular Medicine
Reference21 articles.
1. Dahl P, Danzi S, Klein I. Thyrotoxic cardiac disease. Curr Heart Fail Re. 2008;5:170–6.
2. Akamizu T, Satoh T, Isozaki O, Suzuki A, Wakino S, Iburi T, Tsuboi K, Monden T, Kouki T, Otani H, et al.; Japan Thyroid Association. Diagnostic criteria, clinical features, and incidence of thyroid storm based on nationwide surveys. Thyroid 2012; 22: 661–79.
3. Hammond HK, White FC, Buxton IL, Saltzstein P, Brunton LL, Longhurst JC. Increased myocardial beta-receptors and adrenergic responses in hyperthyroid pigs. Am J Physiol. 1987;252:H283–90.
4. Ross DS, Burch HB, Cooper DS, Greenlee MC, Laurberg P. American thyroid association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid. 2016;26:1343–421.
5. Goldschlager N, Epstein AE, Naccarelli GV, Olshansky B, Singh B, Collard HR, Murphy E; Practice Guidelines Sub-committee, North American Society of Pacing and Electrophysiology (HRS). A practical guide for clinicians who treat patients with amiodarone: 2007. Heart Rhythm 2007; 4: 1250–9.