20

Case Report

21

Hyperthyroidism caused CHF

Hyperthyroidism-caused Congestive Heart Failure in A Young Female: A Case Report

Chii-Chang Yeh1, Hsien-Cheng Huang2

AbstractHyperthyroidism is common in young female, the symptoms and signs of hyperthyroidism are hands

tremor, tachycardia, body weight loss, goiter, exophthalmos, etc. The cardiovascular complications of hyperthyroidism include sinus tachycardia, atrial fibrillation, atrial flutter, and extremely rare cardiac failure. The presence of underlying heart disease and aged patients are susceptible to develop heart failure. This case is 32-year-old female, had once attack of hyperthyroidism 7 years ago, this time re-current hyperthyroidism attack was complicated with congestive heart failure (CHF) and atrial fibril-lation, after treatment with medicine of anti-thyroid drug, propranolol, anticoagulant and diuretic, her disease was got dramatically improved. This case is young and didn't have heart disease or arrhythmia before; however, she was complicated with uncommon cardiac failure, the mortality rate is high(30%) if no early treatment.(Formos J Endocrin Metab 2012; 3(1): 20-24)

Key words: hyperthyroidism, congestive heart failure, atrial fibrillation

1Division of Endocrinology & Metabolism, 2Division of Cardiovascular, Taipei City Hospital, Yang-Ming Branch Correspondence to: Dr. Chii-Chang Yeh, 105 Yusheng street, Shihlin District, Taipei,111, Taiwan (Division of Endocri-nology & Metabolism, Taipei City Hospital Yang-Ming Branch)Tel: 886 2 28353456 E-mail:yeh10271027@yahoo.com.tw

Introduction

Hyperthyroidism is associated with increased cardiovascular morbidity and mortality, primarily due to heart failure and thromboembolism. Sinus tachycardia and atrial fibrillation are frequent car-diovascular signs of hyperthyroidism, heart failure is rare in hyperthyroidism but may occur in the pres-ence of underlying heart disease and aged patients.1 Herein, we described a young female represented with hyperthyroidism, CHF, and atrial fibrillation.

Case Report

A 32-year-old female visiting emergency room(ER) complained palpitation and dyspnea for weeks, her past history had hyperthyroidism first at-

tack 7 years ago, no heart disease or asthma. In ER, her vital signs were blood pressure:116/67 mmHg, pulse rate:138 beats/min, respiration rate: 26 breaths/min, and body temperature: 36.6℃. A physical ex-amination found clear consciousness with dyspnea appearance, exophthalmos was present, goiter was palpable, pitting edema over both legs was also noted. Her breathing sound were basal rales but no wheezing were heard. The heart beat was rapid and irregular. The laboratory analyses revealed WBC:7460/uL, Hgb:11.1 g/dL, platelet:179000/uL, glucose: 89 mg/dL, BUN:10 mg/dL, creatinine: 0.4 mg/dL, AST:48 U/L, ALT:32 U/L, Na: 139 meq/L, K:4.0 meq/L, Ca:8.6 mg/dL, and Troponin-I: 0.001 ng/ml(<0.4); there was no blood gas check. The chest x-ray showed enlarged heart shadow, bilat-eral pleural effusion (Figure 1a). An EKG revealed

20 21

Hyperthyroidism caused CHF

Formos J Endocrin Metab Vol. 3 No. 1: 20-24

Figure 1b. Only right C-P angle blunting(7th day).Figure 1a. Enlarged heart shadow, bilateral pleural effusion.

Figure 2a. Atrial fibrillation with RVR..

22

Chii-Chang Yeh et al

Formos J Endocrin Metab Vol. 3 No. 1: 20-24 23

Hyperthyroidism caused CHF

atrial fibrillation with rapid ventricular response (Figure 2a). Traced back thyroid function test 5 days ago revealed TSH:0.012 uIU/ml(0.35-5.50), FT4: 7.83 ng/dL(0.89-1.76), ATA:7314 U/ml(<60), Anti-TPO:12838 U/ml(<60).

At ER, anti-thyroid drug (propylthiouracil, PTU) 200mg and propranolol 20mg were at once prescribed from oral intake, diuretic (furosemide) 20mg was intravenously infused based on diagnosis of hyperthyroidism and CHF. After admission, the medicine regimen including methimazole 5mg tid, propranolol 10mg tid, warfarin 2.5mg qd, digoxin 0.125mg qd, and furosemide 20mg intravenous q12 hour. The cardiac echo found bi-atrial enlargement, dilated right ventricle and pulmonary trunk, left ven-tricle systolic dysfunction(LVEF=37%), hypokinesis of ventricular septum, small amount of pericardial effusion, moderate mitral & tricuspid regurgitation. Thyroid sona showed homogenous diffuse goiter; thyroid function test was followed in the next day, TSH: 0.010uIU/ml, FT4: 2.36ng/dL, T3: 172 ng/dL(60-181), ATA:7035, Anti-TPO:8679, albumin:3.4 g/dL(3.5-5.2).

After the 7th day, the chest x-ray was followed and showed only right C-P angle blunting (Figure 1b); EKG revealed sinus rhythm (Figure 2b), the 12th day she was discharged.

Discussion

Hyperthyroidism in elderly patients with pre-existing heart disease or hypertension were more susceptible to develop CHF. In addition, the oc-currence of atrial fibrillation could worsen cardiac function, and was a predictor for the development of CHF.2

Prevalence of atrial fibrillation after the age of 75 years is 7% to 8% in men and 2% to 6% in wom-en. Male sex, increasing age, ischemic heart disease, CHF, and heart valve disease are associated with an increased risk of atrial fibrillation or flutter in patient with hyperthyroidism.3

The thyroid gland primarily secrete T4(≒85%), which is converted to T3 by 5'-monodeiodination in the liver, kidney, and skeletal muscle. The heart relies mainly on serum T3 because no myocyte in-

Figure 2b. Sinus rhythm(7th day)

22

Chii-Chang Yeh et al

23

Hyperthyroidism caused CHF

Formos J Endocrin Metab Vol. 3 No. 1: 20-24

tracellular deiodinase activity takes place .4 T3 also increases erythropoietin synthesis, which leads to an increase in red cell mass. Thyroid hormone ef-fect on the heart and peripheral vasculature include decreased systemic vascular resistance(SVR) and increased resting heart rate, left ventricular contrac-tility. In hyperthyroidism, these combined effect in-crease cardiac output 50% to 300%.4

The hyperdynamic circulation caused by hyper-thyroidism may further impair heart function, lead-ing to heart failure and atrial fibrillation. Conversely, tachyarrhythmia may also lead to heart failure due to tachycardia-induced cardiomyopathy.2,3

A few case reports have indicated that hyper-thyroidism too may cause isolated right heart failure, it has been postulated that increased blood volume and more rapid venous return to the right ventricle. Consequently, pulmonary arterial and right ventricu-lar pressures increase, and the right ventricle be-comes dilated, this can result in functional tricuspid regurgitation.5 In addition, pericardial effusion is a extremely rare complication of hyperthyroidism was also reported.6 The cardiac echo of this patient were dilated right ventricle and pulmonary trunk, tricuspid and mitral regurgitation, and small amount pericar-dial effusion.

This time the patient had hyperthyroid state ac-companied with CHF and atrial fibrillation, although hyperthyroidism is common in young female, but heart failure is rarely happened in young patients. This patient was treated by anti-thyroid drug, beta-adrenergic blocker, anti-coagulant, and diuretic, the conditions were got significantly improved.

Primary hyperthyroidism (also called Graves' disease) was diagnosed in her according to high free T4, suppressed TSH level, and increased titer of ATA & Anti-TPO autoantibody. Thyrotoxic crisis or thyroid storm, the clinical pictures are fever, sweat-ing, marked tachycardia and may be accompanied by pulmonary edema or CHF. Early, tremulousness and restlessness are present; delirium or frank psychosis may supervene. As the disorder progresses, apathy, stupor, coma, and hypotension can develop, the con-dition is invariably fatal.7 However, this patient not yet develop to this crisis.

A literature report,2 CHF was the initial clinical presentation in approximately 6% of patients with hyperthyroidism, and half of them had left ventricu-lar systolic dysfunction(LVEF<50%). Symptoms of CHF subsided and LVEF improved after treatment for hyperthyroism. The mortality rate for hyperthy-roidism due to cardiac failure and arrhythmia is 30%, even with treatment.6

The treatment of hyperthyroidism, beta-adren-ergic blockers relieve symptoms such as tachycardia, tremor, anxiety, and heat intolerance. The nonselec-tive agent propranolol has been traditionally used for this purpose. The use of propranolol should be carefully considered in patients with thyrotoxic car-diomyopathy in those with heart failure because of the risk of exacerbation (fall in cardiac output).8 In patients who do not tolerate beta-blocker, a calcium channel blockers such as verapamil or diltiazem can be used as a negative chronotropic agent.1 Caution is warranted, however these agents may lead to he-modynamic instability by further reducing SVR and myocardial contractility.1,4

Thyrotoxic thromboembolism associated with atrial fibrillation may occur even in patients with no underlying heart disease. Therefore, all patients with thyrotoxic atrial fibrillation should receive an-ticoagulation therapy.1 This patient didn't have heart disease, so she was also prescribed warfarin 2.5mg every day.

Digitalis and diuretic may be considered in pa-tients with heart failure and concomitant atrial fibril-lation.4,8 In the absence of chronic atrial fibrillation or underlying heart disease, thyrotoxic atrial fibrilla-tion usually converts spontaneously to sinus rhythm after antithyroid treatment.1

References

1. Roffi M, Cattaneo F, Topol FJ. Thyrotoxicosis and the cardiovascular system: subtle but serious effects. Cleveland Clinic Journal of Medicine. 2003;70:57-63.

2. Siu CW, Yeung CY, Lau CP, et al. Incidence, clinical characteristic and outcome of conges-tive heart failure as the initial presentation in

24

Chii-Chang Yeh et al

Formos J Endocrin Metab Vol. 3 No. 1: 20-24 25

patients with primary hyperthyroidism. Heart. 2007;93:483-7.

3. Frost L, Vestergaard P, Mosekilde L. Hyperthy-roidism and risk of atrial fibrillation or flutter. Arch Intern Med. 2004;164:1675-8.

4. Klein I, Danzi S. Thyroid disease and the heart. Circulation. 2007;116:1725-35.

5. Whitner, TE, Hudson CJ, Smith TD, et al. Hy-perthyroidism presenting as isolated tricuspid re-gurgitation and right heart failure. Tex Heart Inst J. 2005;32:244-5.

6. Ovadia S, Lysy L, Zubkov T. Pericardial effusion as an expression of thyrotoxocosis. Tex Heart Inst J. 2007;34:88-90.

7. Larsen RP, Davies TF, Hay ID. The thyroid gland. In: Jean D. Wilson, Daniel W. Foster, Henry M. Kronenberg, et al, eds. Williams Text-book of Endocrinology. Philadelphia. WB Saun-ders, 1998:460.

8. Ngo ASY, Tan DCL. Thyrotoxic heart disease. Resuscitation. 2006;70:287-90.