Echocardiographic Assessment in Patients of Thyroid Dysfunction – A 1 year Cross-Sectional Study in a Tertiary Care Hospital

Abstract

BACKGROUND & OBJECTIVES: ABSTARCT Thyroid diseases are, arguably, among the commonest endocrine disorders worldwide including India.The heart is an important target organ for thyroid hormone action and the molecular mechanisms that underlie the thyroid hormone based effects have been reviewed in the past. Thyroid hormone is an important regulator of cardiac function and cardiovascular hemodynamic. Hyperthyroidism and hypothyroidism are known to affect cardiovascular system in the number of ways.Cardiovascular adverse effect may start very early in the course of thyroid dysfunction and may remain undiagnosed, unless actively screened due to subclinical nature or non-specific presentation. So there is need to understand common cardiovascular manifestations of different thyroid disorders using appropriate investigations. In this background, the current study was conducted to evaluate the 2 D-EchoCardiography changes in thyroid disorders MATERIALS & METHODS: This study was a cross sectional study, conducted in the department of general medicine, DR.Prabhakar Kore hospital, KLE University, Belgaum. The study included 50 adults, aged above 18 years, with laboratory confirmation of various types of thyroid dysfunction by universal sampling.The data collection for the study was done between 1 31 st December 2107 for one year st Patients with Pre-existing heart diseases like Rheumatic heart disease, Ischemic heart disease, hypertensive heart disease and cardiomyopathy. Ischemic heart disease were excluded from the study. Patients who were taking medications that alter the thyroid function such as beta blockers, lithium, oral contraceptive pills, steroids, and alcohol were also excluded. Patients January 2017 to with the chronic obstructive pulmonary disease, severe anaemia or any other endocrinal disorders were also excluded. A detailed history was taken to evaluate symptoms and duration related to thyroid dysfunction. Special emphasis was taken to rule out cardiac dysfunction. A detailed examination was performed on every patient. All the patient were subjected to free T3, Free T4, Free TSH and two-dimensional Echocardiography.Transthoracic echocardiography was performed using a commercially available echocardiographic system (EPIQ), with gated ECG .4 chamber and M-Mode Doppler and tissue Doppler imaging images are digitally acquired by X5-1 Matrix probe. Comparison of volume of all four cardiac chambers by 2D and 3 D echocardiography in normal individual measurements were symmetrically performed by offline analysis with an independent reader, blinded to clinical data. Descriptive analysis was carried out by the mean and standard deviation for quantitative variables, frequency and proportion for categorical variables. Data was also represented using appropriate diagrams like bar diagram and pie diagram. Since the study was only a descriptive study, no inferential statistical analysis was performed and no P values were reported. IBM SPSS version 22 was used for statistical analysis. RESULTS: The mean age of the subjects was 39.18 ± 14.32 years with higher female preponderance. The most common thyroid dysfunction was hyperthyroidism in 41.20% of the study population, followed by 15 % of subjects with primary hypothyroidism and 15% of subjects with subclinical hypothyroidism. Most common co-morbidities were anaemia in 23.50% participants, hypertension in 19.6% and diabetes mellitus in 9.8% of study population.The pulse, systolic and diastolic blood pressure were significantly higher among hyperthyroidism group, as compared to the other two groups. Among 15 people with Primary hypothyroidism, sinus bradycardia was the most common ECG feature observed in 8 (53.3%) of the study population. The other common ECG features were low voltage criteria and right bundle branch block seen in 2 (13.33%) subjects each. One subject (6.67%) had prolonged QT interval. Among 21 people with hyperthyroidism, the most common ECG finding was sinus tachycardia seen in 12 (57.14%) of subjects. Atrial fibrillation was observed in 3(14.28%) subjects, and low voltage complexes were observed in 2 (9.52%) of people.Among 15 subjects with subclinical hypothyroidism, the only ECG abnormality was sinus bradycardia seen in 2 (13.33%) of the subjects.Among the people with hyperthyroidism, 8 (38.10%) participants each had normal and tachycardia. 4, (19.04%) participants had pulmonary artery hypertension, and 2 (9.52%) participants had dilated cardiomyopathy. Among the people with primary hypothyroidism, 11 (73.33%) participants had type 1 diastolic dysfunction, 4 (26.67%) participants had pericardial effusion, 3 (20%) participants had pulmonary artery hypertension, and 2 (13.33%) participants had normal. Among the people with subclinical hypothyroidism, 8 (53.33%) participants had type 1 diastolic dysfunction, 6 (40%) participants had normal, 4 (26.67%) participants had pulmonary artery hypertension. CONCLUSIONS: The study has highlighted the profile of cardiac dysfunction among different types of thyroid dysfunction. No statistical associations could be tested due to limited sample size. Hence large scale prospective studies on the subject are needed to guide clinical practice.