What It Means If You Have Low Blood Pressure But a High Heart Rate

This combo could signal a heart rhythm problem
Smart watch displaying heart rate monitoring capabilities

You may be ecstatic that you finally got your blood pressure lowered, only to notice your heart seems to be racing — ALL THE TIME. So what gives when you successfully hit the magic number of <120/<80 mm, but your heart rate remains high?

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Heart rhythm specialist Tyler Taigen, MD, says sometimes this is normal and sometimes it’s not.

When is this combo not a big deal?

Sometimes blood pressure and high heart rate occurs momentarily. For example, Dr. Taigen explains, when we stand up:

  1. Blood pools in the veins of our legs and gut.
  2. Less blood travels to the heart muscle, so there isn’t much for the heart to pump out.
  3. The nervous system automatically increases the heart rate to get the blood pumping.
  4. Meanwhile, the blood pressure drops a bit because the force of blood moving through the veins is lower.

However, that phenomenon is short-lived. When the heart rate stays consistently high while blood pressure is low, there may be something problematic going on.

What else can cause an elevated heart rhythm along with low blood pressure?

When the heart’s electrical circuits aren’t properly functioning, the result can be a high heart rate coupled with low blood pressure, Dr. Taigen explains.

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“When the heart has a fast, abnormal rhythm — anything over 100, but closer to 160 beats per minute — it can’t adequately fill with blood. The chaotic electrical signaling causes the heart muscles to be out of sync between the top and bottom chambers,” he says. “Less efficiency in the heart means less blood is pumping through the body — which means low blood pressure.”

You may have an abnormally fast heart rhythm when…

You may not know your heart rhythm is pacing more like a rabbit than a tortoise. But all that racing and ineffective blood pumping result in oxygen-deprived organs and tissues. It’s worth a trip to the doctor when you:

  • Are short of breath.
  • Feel lightheaded.
  • Experience a racing heart.
  • Have chest pain.
  • Faint.
  • Generally feel lousy.

Be still, my heart: How a heart rhythm specialist can help

When this happens, electrophysiologists first try and slow the heart rate using medicines, Dr. Taigen says. “But these medicines, known as beta-blockers or calcium channel blockers, can also drop the blood pressure,” he notes. “Quite often, there’s not much room for blood pressure to go lower.”

If your blood pressure is too low for medications, a procedure called direct current cardioversion can get the rhythm back to normal.

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“With this procedure, we put pads on the front and back of the chest and sedate the patient for a minute or two,” Dr. Taigen explains. “When they are asleep, we deliver a shock that stops the heart from beating irregularly, so the natural heartbeat resumes.”

Once the heart rhythm is back to normal, an electrophysiologist determines if a more permanent treatment is needed. These could include:

  • Ablation: This procedure uses cold or heat energy to stop faulty electrical signals.
  • Pacemaker: Doctors place a small device under the skin to send electrical impulses that change the heart rhythm.
  • Implantable cardioverter defibrillator (ICD): Like a pacemaker, the ICD works by detecting and stopping faulty heart rhythms with electrical signals.
  • Surgery: Surgeons create scar tissue with incisions to permanently interrupt faulty electrical pathways in the heart.

Does this really matter if you’ve finally got low blood pressure?

Heart rhythm problems that affect the upper heart chamber (atrium) can put you at an increased risk for stroke, heart failure or death. Here’s why:

  1. The disorganized electric firing in the top chamber of your heart causes it to quiver.
  2. The blood swishes back and forth in a pouch off to the side of the atrium (called the left atrial appendage).
  3. People who are older, have heart disease or diabetes may be prone to the blood clotting in that left atrial appendage.
  4. If the clot breaks free, the heart can pump it to the brain and block blood flow to brain tissue — which is how a stroke happens.

If you’re diagnosed with an irregular heart rhythm, you may need to take blood-thinning medications, plus one of the treatments above, to decrease your risk of stroke. Your doctor can help you get the right care to keep everything steady and stable — so the only time your heart is racing is while you’re watching “Stranger Things.”

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