Graves' Disease Complicated by Ventricular Fibrillation in Three Men Who Were Smokers

Abstract

Background: Thyrotoxicosis is known to be associated with sinus tachycardia and supraventricular tachyarrhythmias, but rarely with ventricular fibrillation (Vf), which has only occurred in some patients with hypokalemic periodic paralysis or ischemic heart disease. Patient Findings: We present three men who were transferred to our hospital with Graves' disease who developed idiopathic Vf. None of them had hypokalemic periodic paralysis or ischemic heart disease but all were smokers. None of other patients with thyrotoxicosis (587 females and 155 males) who were seen at our hospital, in the period during which the three men were seen, had idiopathic Vf. In our three men with thyrotoxicosis and idiopathic Vf, there was no identifiable underlying heart disease. One of the three patients died of hypoxic encephalopathy. The other two men did not have recurrent Vf after their thyroid function normalized. Summary: These cases and a review of similar cases in the literature imply that improving thyrotoxicosis seems to be effective for treating idiopathic Vf in some patients. Conclusions: Our findings suggest that thyroid hormone excess might play a direct role in the development of Vf in susceptible individuals. Our experience with these three patients suggests that smoking men with thyrotoxicosis likely have an increased risk for Vf, even if they do not have other predisposing factors.

Unusual Manifestation of Graves' Disease: Ventricular Fibrillation

“…The majority of cases of VF induced by thyrotoxicosis occur in the context of thyrotoxic periodic paralysis with severe hypokalemia [4] . In our literature review, we identified only 9 cases (in 7 case reports) of VF caused by thyrotoxicosis without hypokalemia ( table 1 ) [5,6,[10][11][12][13][14] . Among these, all of the patients except Brooks' case had neither previous history of cardiac disease nor family history of sudden death.…”

“…Thyroid hormones may affect those intracellular pathways and cause hyperreactivity, leading to spasms, followed by myocardial ischemia and possibly VF. The characteristics of vasospasm due to thyrotoxicosis are as follows: age <55 years [16] , higher prevalence in woman [16] , mild symptoms of thyrotoxicosis [17] , and smoking history [11] . In the present case, although we could not demonstrate vasospasm induced by acetylcholine in the coronary arteriography, coronary artery spasm is one of the possible causes of VF as suggested by the patient's clinical history and late gadolinium enhancement on cardiac MRI.…”

A case of thyroid storm with cardiac arrest

“…A cardiac arrest is rarely led by hypokalemia 3. In contrast, Ueno et al,1 Ando et al,4 and Jao et al5 described cases of a cardiac arrest with a thyroid storm where the patients did not have hypokalemia or other signs of a complicating disorder.…”

“…It has been reported that a thyroid storm may affect the heart owing to early repolarization and coronary artery spasms; in addition, a smoking habit can also contribute to early repolarization and coronary artery spasms 4. The effects of thyroid hormones on the heart are as follows: accelerated protein and messenger RNA synthesis in myocardial cells; Na–K adenylpyrophosphatase (ATPase) hyperactivity; increased Ca 2+ transport; an increased number of β-receptors; a reduced refractory phase; and a low stimulus threshold 8…”

Cardiac arrest triggered by hyperkalemia during red blood cell transfusion: a case report and literature review

“…Hyperthyroidism is also one of the differential diagnoses for her cardiac arrest. It has been reported that a thyroid storm may affect the heart owing to early repolarisation and coronary artery spasms (Ando et al, 2011). The effects of thyroid hormones on the heart are as follows: accelerated protein and messenger RNA synthesis in myocardial cells, Na-K adenylpyrophosphatase (ATPase) hyperactivity, increased Ca 2+ transport, an increased number of -receptors, a reduced refractory phase and a low stimulus threshold (Klein & Ojamaa, 2001).…”