Q. A 54-year-old female is brought to the clinic by her daughter. Her daughter reports that she has noticed that her mother begins to stumble as she walks. The patient states that she has been feeling dizzy for the last 3 weeks. She notes that the dizziness she has been experiencing is not related to postural changes and has not identified any triggers. She has not experienced ear or chest pain, difficulty breathing or profuse sweating. The patient does not have a history of ear infections; however, her past medical history includes hypertension and type 2 diabetes, which are controlled with lifestyle modifications and medication. The patient’s blood pressure is 150/90 mmHg. ECG shows an irregular heart rhythm with progressive prolongation of the PR interval. What would be the most likely diagnosis?