Study of Hypothyroid Related Atrioventricular Block in Elderly Hypothyroid Patients and Assessment of Any Reversal After L-Thyroxin Therapy.

We intend to study the pattern of atrioventricular conduction blockage in hypothyroidism in elderly population and assessment of any reversal after Lthyroxin therapy. Aims : 1) To detect hypothyroid related AV block in elderly hypothyroid patients. 2) To supplement L-thyroxin for 6 weeksand check whether the AV conduction is restored or not. Settings and design : The proposed study is a hospital based case control study followed by interventional one. Hypothyroid elderly subjects attending OPD over a period of one year were considered for the purposes of observation. Age and gender matched controls were selected simultaneously. Methods and materials : 42 elderly (>60 years) hypothyroid patients were selected as case and 45euthyroid sage and gender matched subjects as control. ECG was done to asses the degree of AV block. Any degree of AV conduction block noted, was supplemented with L-thyroxin for 6 weeks and later resting ECG was done to assess whether the normal AV conduction was restored or not. Statistical analysis : Chi square test done between the case and control group and paired T test done before and after L-thyroxin supplementation. Results : Chi square test revealed that out of 42 cases, a significant proportion of 62% had increased P-R interval (P<.001), whereas 76% out of 45 control had normal P-R interval.After L-thyroxin supplementation in 69% of the cases, normal P-R interval was restored (P< .001, paired T test value 13.484). Conclusion : In hypothyroid patients AV block detected in resting ECG should be a matter of concern, because if the conduction block is reversed to normal sinus rhythm by thyroxin supplementation, unnecessary pacemaker implantation can be avoided.

Seguimento de pacientes de alto risco com carcinoma diferenciado de tireóide sem doença persistente após a terapia inicial / Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy / Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy

Este estudo avaliou o seguimento de pacientes com câncer de tireóide de alto risco, após a terapia inicial. Foram selecionados 125 pacientes de alto risco (tumor >4 cm e/ou invasão extra-tireoidiana e/ou metástases linfonodais e idade >45 anos), com ressecção tumoral completa. Todos foram tratados com tireoidectomia total e ablação com 131I [3,7­5,5 GBq (100­150 mCi)] e foram excluídos 18 casos (14,8 por cento) com metástases na PCI pós-dose (t-PCI). O valor preditivo negativo da Tg estimulada <1 ng/ml combinada ao US cervical na primeira avaliação (6­12 meses após a terapia ablativa) foi de 96,2 por cento para ausência de recidivas em até 5 anos. Este valor aumentou para 98,7 por cento quando acrescentamos a PCI com 185 MBq (5 mCi) 131I (d-PCI). O valor preditivo positivo (VPP) da Tg estimulada >1 ng/ml foi de 52 por cento para presença de metástases detectadas até 5 anos depois, mas considerando apenas pacientes que apresentaram d-PCI e US negativos inicialmente, o VPP foi 19 por cento (9 por cento se Tg 1­10 ng/ml vs. 40 por cento se Tg >10 ng/ml). Tg reduziu espontaneamente nos pacientes com Tg estimulada >1 ng/ml na primeira avaliação, US e d-PCI negativos e sem recidiva no seguimento, sendo indetectável em metade destes ao final de 5 anos. No primeiro ano após a terapia ablativa, 20 pacientes tiveram captação em leito tireoidiano na d-PCI com Tg estimulada e US negativos e não foram tratados com 131I; estes evoluíram sem recidiva e 60 por cento apresentavam uma d-PCI sem nenhuma captação após 5 anos. Em pacientes sem doença aparente (no US e d-PCI) e Tg estimulada <1 ng/ml, a recidiva em 5 anos foi de apenas 1,3 por cento. Um algoritmo para o seguimento de pacientes de alto risco após a terapia inicial é apresentado por este estudo.

This study evaluated the follow-up of high-risk patients with thyroid cancer after initial therapy. A total of 125 high-risk patients (tumor >4 cm and/or extrathyroid invasion and/or lymph node metastases, and age >45 years), with complete resection of the tumor, were selected. All patients underwent total thyroidectomy and ablation with 131I [3.7­5.5 GBq (100-150 mCi)]. Eighteen patients (14.8 percent) presenting metastases on post-dose whole-body scan (RxWBS) were excluded. The negative predictive value of stimulated Tg <1 ng/ml in combination with neck US during first assessment (6­12 mo. after ablative therapy) was 96.2 percent for the absence of recurrence up to 5 years. This value increased to 98.7 percent when adding WBS performed with 185 MBq (5 mCi) 131I (DxWBS). The positive predictive value (PPV) of stimulated Tg >1 ng/ml was 52 percent for the detection of the presence of metastases up to 5 years; however, considering only patients with initially negative DxWBS and US, the PPV was 19 percent (9 percent if Tg of 1­10 ng/ml vs. 40 percent if Tg >10 ng/ml). Tg levels decreased spontaneously in patients with stimulated Tg >1 ng/ml during first assessment, negative US and DxWBS, and no recurrence during follow-up, with Tg being undetectable in half these patients at the end of 5 years. Twenty patients presented uptake in the thyroid bed upon DxWBS during the first year after ablative therapy, with stimulated Tg and US being negative, and were not treated with 131I; these patients did not relapse and no uptake on DxWBS was observed in 60 percent after 5 years. Recurrence after 5 years was only 1.3 percent in patients without apparent disease (negative US and DxWBS) and stimulated Tg <1 ng/ml. An algorithm for the follow-up of high-risk patients after initial therapy is presented in this study.