A case report with complete heart block related with hypothyroidism emerging after thyroidectomy

Abstract

The development of complete heart block is very rare in hypothyroid patients. A 22 year-old female patient was accepted to our clinic with the symptoms of the dizziness and easy fatigue. It was learned that she had these complaints after the thyroidectomy operation performed 11 months ago because of the cosmetic reasons. She was not using any drug that affects the heart rate. In her physical examination the pulse rate was measured as 34/min. Blood pressure was 90/60 mmHg. Electrocardiographic examination showed the complete heart block. Echocardiographic examination was normal except minimal mitral regurgitation. The biochemical examination showed that thyroid hormones decreased significantly [FT3:1.86 pg/ml (N:2.30-4.20) FT4.0.48 ng/ml (N:0.80-1.50)], TSH was found very high [169.5 IU/ml (N:0.35-5.50 IU/ml)]. Thyroid replacement therapy was begun and the dosage was increased gradually. The hormone levels reached to normal levels at the second month of the therapy (FT3:3.44 pg/ml, FT4:1.78 ng/ml, TSH:0.28 IU/ml). But in spite of these values, the heart block persisted and the permanent cardiac pacemaker implantation was planned and suggested to the patient. But she refused this decision and was discharged from the hospital with her own request. It was learned from her relatives with phone that approximately four months later after her discharge she died suddenly in her home. In conclusion, it can be thought that the complete heart block developed because of the hypothroidism is resistant to the hormonal therapy, although the hormon values can be increased to the normal levels. It can not be converted to normal sinus rythm may be due to the permanent damage in the conduction system. The result may be fatal if the permanent pacemaker implantation can not be performed as soon as possible.