Fast heart rate at rest

Overview

In an adult at rest the normal pulse is 60–100 beats per minute; most fit people have lower values. Tachycardia means a resting pulse above 100. It can be a normal reaction of the body (fever, anxiety, coffee) or a sign of a disorder that needs to be looked for.

While palpitations are the sensation that the heart is beating, tachycardia is a measured value. You may feel both together, but not always.

How to measure your pulse

• sit for 5 minutes at rest, with no coffee, smoking or walking beforehand
• place two fingers (not the thumb) on the wrist, below the base of the thumb
• count the beats for 30 seconds and multiply by 2 (if the rhythm is irregular, count for 60 seconds)
• note whether the rhythm is regular or not, and what you feel

Blood pressure monitors or smart watches usually give the pulse as well; their values are approximate. Notes from several days help the doctor a lot.

Common causes

• anxiety, stress, fear and pain
• caffeine, energy drinks, smoking, alcohol
• fever and infections
• dehydration and blood loss
• anemia (see iron-deficiency anemia)
• an overactive thyroid (hyperthyroidism); an underactive thyroid usually has the opposite effect (see hypothyroidism)
• medicines: some asthma inhalers, decongestants, thyroid hormone in excess dose
• pregnancy and menopause
• poor physical fitness

Causes from the heart

• Supraventricular tachycardia — starts and stops suddenly, often 150–220 beats per minute
• Atrial fibrillation — a fast and completely irregular pulse
• Ventricular tachycardia — rarer but dangerous, often with heart disease
• Heart failure and valve or heart muscle disease

The doctor tells these apart with an ECG and, when episodes come and go, with a Holter.

How it is assessed

• History: when it starts, how long it lasts, what triggers it, whether there is fainting or chest pain, medicines, coffee, alcohol.
• ECG — can capture the rhythm when it is present during the visit.
• 24–48-hour Holter ECG — when the beats come and go (see ECG or Holter).
• Blood tests: hemoglobin, TSH, electrolytes, glucose.
• Echocardiography — to see the structure and function of the heart (see echocardiography).

What you can do yourself

• cut down on coffee, energy drinks, smoking and alcohol
• drink enough water and sleep enough
• try to lower stress: slow breathing, walks, gentle physical activity
• do not change medicines yourself; ask your doctor if you suspect one of them
• keep a diary with the time, pulse and sensations

When to see a cardiologist

• the resting pulse is repeatedly above 100 with no clear cause
• the beats start and stop suddenly or are completely irregular
• you have dizziness, fainting, chest pain or dyspnea
• you have heart disease, hypertension, diabetes or a family history of sudden death
• the symptoms are becoming more frequent