45 year old female, not taking any medication. last may found out i have low resting heart rate anywhere from 42 to 60 and high blood pressure of 160/90, perimenopause. is there a disease that can cause both? could they be related?

With the slow heart rate your heart is increasing the strength & volume of blood with each heartbeat in order to compensate and this causes increase in BP. A heart rate of 42 when you're up &about is inappropriate and can cause lightheadedness & shortness of breath with exertion. The next step is to wear an outpatient cardiac monitor to accurately assess whether you have significant bradycardia.

A low resting heart rate can elevate your systolic blood pressure without there being any other problem. The anxiety related to this question you are raising also contributes to the high systolic pressure. Please see your doctor to evaluate you further. An electrocardiogram during the visit will also in help in determining the potential causes and the need for treatment if any.