Chronic uncontrolled hyperglycemia is associated with an increased incidence of coronary artery disease (CAD), cardiac failure, diabetic nephropathy, diabetic retinopathy, and associated mortality. A 72-year-old female presented to the OPD with multiple episodes of loss of consciousness for the past one month. The patient also had other comorbidities like hypertension, diabetes mellitus, and hypothyroidism. On systemic examination, her BP was 124/77 mmHg (supine) and 116/72 mmHg (standing), pulse rate was 56 beats per minute. She had a loss of vibration sense in both lower limbs up to the ankle. Fundus examination showed Non-proliferative diabetic retinopathy (NPDR). The rest of the systemic examination was clinically normal. Her HbA1C was 8.1%, and other routine investigations were within normal limits. Electrocardiography (ECG) showed sinus bradycardia. Echocardiography showed normal ventricular function with no evidence of ischemic heart disease. 24-hour Holter ECG revealed Sinus bradycardia with Intraventricular conduction defect (IVCD), third-degree AV block with junctional beats, and rare supra-ventricular ectopics. This is a case of Type 2 Diabetes mellitus with complete heart block (CHB) of spontaneous onset. Other causes of AV block have been ruled out, and it seems this case of CHB is possibly due to cardiac autonomic neuropathy (CAN). Multiple factors like the duration of diabetes, poor glycemic control, metabolic derangements, and genetic factors determine CAN. This case emphasizes that patients with type 2 diabetes without ischemic heart disease (IHD) can develop CHB spontaneously
