Your patient is a 58-year-old female with symptoms of atypical angina persisting for the past 3 months when she climbs the stairs in her house. She is 5’ 6” and weighs 178lbs. Her current medications include 20mg of Lisinopril per day and a multivitamin. She has abstained from taking her medication this morning as well as from her normal 20-ounce coffee. She does not smoke but drinks a glass or two of wine on the weekends. She is currently sedentary as she has a history of knee and back problems. She underwent graded exercise testing 5 years ago and achieved a peak MET level of 12 METs. She can perform most ADLs without issue. Her resting ECG shows normal sinus rhythm and she shows no absolute or relative contraindications to symptom-limited maximal exercise testing. Resting HR: 62 bpm Resting BP: 128/80 mmHg

Calculate the heart rate (in bpm) that would she have to achieve during the exercise test in order for the test to provide adequate stress for revealing exertional ischemia (hint, its a of the max HR, we often solve for this in our stress testing interpretations)