What causes resting heart rate to be higher during exercise?

Question

Hi doctor,

I am a 53-year-old male with a resting heart rate of 111 to 116 bpm, also demonstrates a heart rate of 70 bpm with exercise but is asymptomatic. I am currently taking Metoprolol and Metformin. My recent BP recordings are 138/90 mmHg. What do you suggest? Please reply.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

Resting tachycardia, as in your case, may be a benign finding in many individuals. You mentioned your heart rate goes up to 70 bpm (beats per minute) with exercise, and I guess you meant 170 bpm. So, firstly, sinus tachycardia does not necessarily imply cardiac abnormality. It may simply indicate elevated sympathetic activity. So, there are a few factors that should be ruled out. Firstly, you should obtain an ECG (electrocardiogram) to confirm sinus tachycardia and an echocardiogram to rule out the cardiac cause. Also, a thyroid profile should be obtained. I guess you do not have any psychological issues like stress or anxiety, which can also cause this problem.

Also, ensure you have adequate and uninterrupted sleep at night. In addition, your heart rate should be checked at rest for a few minutes but not after consuming caffeinated drinks, which can elevate your heart rate. In addition, Metoprolol (beta blocker) withdrawal may also cause tachycardia. So, if we do not find any cause, it is inappropriate sinus tachycardia, a benign condition. In that case, your Metoprolol dosage needs to be increased. If the Metoprolol dose cannot be increased, you may need to start Ivabradine (hyperpolarization-activated cyclic nucleotide-gated channel blocker). Also, regular exercises would increase vagal tone and restore heart rate to a lower level.

Kindly consult a specialist, talk with them, and take the medications with their consent. I hope this helps you. Please get back to us if you have any questions. Take care.

Answer 2

Hi,

Welcome back to icliniq.com.

So your heart rate falls to 70 bpm with exercise. Now, if we consider your heart rate to be more than 100 bpm just before exercise and as you start to exercise, it falls to 70 bpm, then it is likely an error by the machine. Because it is not possible, as the heart rate would either remain constant or increase, but it can never go down.

It is possible that at some particular point in time, the heart rate is more than 100 bpm, and at some point, it is 60 to 70 bpm. It is normal. It is also normal that your heart rate with mild exercise remains around 70 bpm, but in that case, your heart rate before exercise must be in the range of 60 to 65 bpm.

Metoprolol also tends to keep the heart rate under control and prevent the heart rate from rising drastically. So, considering the overall picture and your being asymptomatic, I do not think this is significant. I hope this was helpful. Take care.