An Observational Study of Electrocardiographic Changes for Diagnosing Arrhythmias in Patients with Hypothyroidism

Background: Hypothyroidism is a common endocrine disorder associated with multiple cardiovascular manifestations, including electrocardiographic (ECG) abnormalities and arrhythmias. Early detection of these abnormalities may help reduce cardiovascular morbidity. Aim: To evaluate electrocardiographic changes associated with hypothyroidism, subclinical hypothyrodism, overt hypothyrodism, euthyrod and identify associated ECG abnormalities among hypothyroid and subclinical patients Methods: This observational study was conducted in the Department of Emergency Medicine at World College of Medical Sciences and Research, Jhajjar, Haryana, India. A total of 40 patients diagnosed with hypothyroidism were included. Detailed clinical evaluation, thyroid profile assessment, and 12-lead ECG analysis were performed. ECG parameters including heart rate, PR interval, QT/QTc interval, axis deviation, ST-T changes, ventricular hypertrophy, and arrhythmias were evaluated. Results: Among the 40 patients studied, females constituted 34 (85%) and males constituted 6 (15%). Overt hypothyroidism was present in 19 (47.5%) of patients, while 15 (37.5%) had subclinical hypothyroidism. ECG abnormalities commonly observed included low-voltage complexes 14 (35%), ST-T changes/T-wave inversion 11 (27%), bradycardia 7 (17%), tachycardia 5 (12.5%), and QT interval prolongation 6 (15%), QT interval decreased 4 (10%) QTc interval increased 6 (15%), QTc increased 6(15%). Right axis deviation was observed in 22 (55%), Left axis deviation 9 (22.5%) of patients. Ectopic were noted in 7 (17.5%), SVT in 2 (5%), Sinus arrhythmia in 4 (10%), Sick sinus syndrome in 2 (5%) of cases. Left ventricular hypertrophy were noted in 7 (17.5%), Right ventricular hypertrophy in 6 (15%), Left ventricular hypertrophy in 7 ((17.5%). The mean heart rate was 74.8 beats per minute, median of heart rate was 75.2 beats per minute and mode of the heart rate was 76 beats per minute was calculated. Conclusion: Hypothyroidism is associated with several ECG abnormalities including low-voltage complexes, QT/QTc abnormalities, ST-T changes, conduction defects, and ventricular arrhythmias. ECG serves as an inexpensive, non-invasive, and valuable tool for early cardiovascular assessment in hypothyroid patients.