What causes heart rate to increase when standing up?

Question

Hi doctor,

I am a 26-year-old healthy male, standing 5 feet 8 inches tall and weighing 160 pounds. I exercise regularly and consider myself healthy. I recently visited a cardiologist and underwent a cycloergometer test (Bruce stage 4 protocol). During the test, my blood pressure remained normal, but my heart rate increased significantly to 194 beats per minute. Without the ability to regulate my pace, I felt as though I had hit a wall. I experienced lightheadedness, slightly blurred vision, and tingling sensations in my legs. This occurs every time I run, so it is not a one-time occurrence. My resting blood pressure was recorded at 132/80 mmHg, and the ECG (electrocardiogram) showed a sinus rhythm of 113 beats per minute. During the test, I exceeded the maximum load by 5 percent and reached 111 percent of the maximum heart rate for my age (194 bpm). My blood pressure increased to 160/60 mmHg. The base ECG at maximum load did not show significant changes, and my blood pressure normalized within two minutes. When I stand up after sitting for a while, I often experience blurry and blacked-out vision, which can be severe. My breathing is quite shallow, and I feel tired most of the time, often experiencing muscle fatigue. These symptoms worsen when I am hot or dehydrated.

I performed a "standing up test" on my own, measuring my heart rate while sitting relaxed several times, which yielded readings of 62, 64, 67, 70, and 73 beats per minute. Zero to two minutes after standing up, the values were 74, 88, 90, 97, and 93 beats per minute. After two minutes, my heart rate was 77 beats per minute, and after five minutes, it was 84 beats per minute. I noticed an increase of around 30 bpm in the first two minutes. When transitioning quickly from lying down to standing up, my heart rate jumps from 63 to 105 beats per minute.

What could be causing these symptoms, and how can I address them? So far, I have tried increasing my water intake and have been drinking plenty, yet I still feel dehydrated. I have also attempted to increase my salt intake.

Please suggest.

Answer 1

Hi,

Welcome to icliniq.com.

I have reviewed your query and understand your health issues. Please do not worry, as you have consulted the appropriate expert physician who will address all of your medical concerns.

Your body mass index is normal for your age. Thank you for attaching your EKG (electrocardiogram); it is completely normal after meeting all the necessary criteria (attachments removed to protect the patient’s identity). However, your cycloergometer cardiac stress test and case history show some abnormalities, particularly a high heart rate. You also appear to have orthostatic hypotension.

I recommend that when you transition from lying down or sitting, you do so slowly and with a pause, rather than getting up quickly. This will help significantly. Compression stockings may also assist in preventing blood from pooling in your lower extremities and dependent areas of your body. Please ensure you stay well-hydrated, and consider using an oral electrolyte solution, as it is a balanced drink that may be beneficial for you. Avoid taking extra salt from now on.

I would like you to have a complete blood count with differential, a screening test for hemoglobin S, kidney function tests, liver function tests, fasting blood sugar levels, and a fasting lipid profile. Please follow up by uploading the results. Additionally, check your blood pressure three times a day and keep a record with dates and times for approximately three days. Upload that chart as well for a detailed follow-up. Once I receive the requested workup, I will be in a better position to treat you based on evidence and with a clearer understanding of the reasons behind your symptoms.

I hope this helps you.

Thank you.

Answer 2

Hi,

Welcome back to icliniq.com.

I appreciate your efforts in regularly monitoring your blood pressure and creating a chart for it. I have thoroughly reviewed your attached reports (attachments removed to protect the patient’s identity) and understand your genuine concerns. Almost all of your blood work is normal, and your liver is functioning well. Your lipid profile is also good. Both your blood pressure and heart rate are normal, indicating that there is nothing wrong in that regard. Based on your case so far, you do not have any major cardiovascular disease.

Thanks and regards.