I have ischemic heart disease called microvascular angina. My charge 5 has reliably predicted my angina flare ups every time for a year now. I do moderate walking regularly (18 minute mile) and always have angina flare ups during my walk. My Fitbit app always shows an inaccurate heart rate increase of 20 to 40 bpm during my 5 minute long angina flare ups. The stronger my angina the higher my heart rate. I have checked the charge 5 readings against a holster monitor and a Polar heart rate chest strap and the high charge 5 readings during my angina attacks are inaccurate. My question is how does the Fitbit charge 5 algorithm accurately predict my angina and does Fitbit know this capability. I find this record of an angina flare up very useful.
