Patient presents with symptoms suggestive of Tachycardia-Bradycardia Syndrome (TBS), also known as brady-tachy syndrome.  The patient reports experiencing palpitations, lightheadedness, dizziness, syncope, near-syncope, and fatigue.  These episodes are intermittent and variable in duration.  Electrocardiogram (ECG) findings confirm the diagnosis, demonstrating alternating episodes of supraventricular tachycardia, most commonly atrial fibrillation, followed by periods of significant bradycardia, including sinus bradycardia, sinus pauses, or sinoatrial block.  The patient's medical history includes hypertension and hypothyroidism, both of which are potential contributing factors to the development of TBS.  Differential diagnoses considered include sick sinus syndrome (SSS), atrial fibrillation with slow ventricular response, and other supraventricular tachycardias with varying conduction.  Initial treatment plan includes addressing underlying medical conditions, optimizing medications, and patient education regarding symptom management.  Medication review will focus on potential exacerbating factors, and adjustments will be made as clinically indicated.  Further evaluation for pacemaker implantation will be considered based on symptom frequency, severity, and response to medical management.  The patient has been informed of the risks and benefits of various treatment options, including pacemaker therapy.  Follow-up appointment scheduled to monitor symptom control and ECG findings.  ICD-10 code I49.5, Sick Sinus Syndrome, is used for coding purposes, as there is no specific ICD-10 code for Tachycardia-Bradycardia Syndrome.  CPT codes for evaluation and management, as well as any procedures performed, will be documented accordingly.