How Does Atropine Affect Heart Rate?


The use of atropine in cardiovascular disorders is mainly in the management of patients with bradycardia. Atropine increases the heart rate and improves the atrioventricular conduction by blocking the parasympathetic influences on the heart.

Does atropine cause tachycardia or bradycardia?

Atropine sulfate causes bradycardia in doses which are greater than the usual anticholinergic doses producing tachycardia (Shucard and Andrew, 1977, Res.

When does atropine cause bradycardia?

Atropine-induced bradycardia is traditionally ascribed to central vagal stimulation, although bradycardia has also been observed after administration of quarternary amines. Pirezepine, a selective M1-antagonist, causes bradycardia in therapeutic doses for which a peripheral mechanism is postulated.

What are the side effects of atropine?

COMMON side effects

  • visual sensitivity to light.
  • blurred vision.
  • dry eye.
  • dry mouth.
  • constipation.
  • decreased sweating.
  • reactions at the site of the injection.
  • intense abdominal pain.

How much atropine should I take for bradycardia?

The recommended atropine dose for bradycardia is 0.5 mg IV every 3 to 5 minutes to a maximum total dose of 3 mg. Doses of atropine sulfate of <0.5 mg may paradoxically result in further slowing of the heart rate.

How atropine works for the treatment of bradycardia?

Atropine works by poisoning the vagus nerve, thereby removing parasympathetic inputs to the heart. This works beautifully for vagally-mediated bradycardia (e.g. vagal reflexes, cholinergic drugs).

What is the drug of choice for bradycardia?

The drug of choice is usually atropine 0.5–1.0 mg given intravenously at intervals of 3 to 5 minutes, up to a dose of 0.04 mg/kg. Other emergency drugs that may be given include adrenaline (epinephrine) and dopamine.

What is the indication for atropine?

Atropine Sulfate Injection, USP, is indicated for temporary blockade of severe or life threatening muscarinic effects, e.g., as an antisialagogue, an antivagal agent, an antidote for organophosphorus or muscarinic mushroom poisoning, and to treat bradyasystolic cardiac arrest.

Does atropine slow heart rate?

Low-dose atropine slows heart rate but does not change overall levels of MSNA. High-dose atropine causes a decrease in MSNA and tachycardia.

When should atropine be used?

Atropine is a prescription medicine used to treat the symptoms of low heart rate (bradycardia), reduce salivation and bronchial secretions before surgery or as an antidote for overdose of cholinergic drugs or mushroom poisoning. Atropine may be used alone or with other medications.

What is the antidote of atropine?

The antidote to atropine is physostigmine or pilocarpine.

Does atropine increase BP?

However, when given by itself, atropine does not exert a striking or uniform effect on blood vessels or blood pressure. Systemic doses slightly raise systolic and lower diastolic pressures and can produce significant postural hypotension.

When should you not take atropine?

myasthenia gravis, a skeletal muscle disorder. closed angle glaucoma. high blood pressure. coronary artery disease.


What conditions will atropine not increase heart rate?

Atropine has little effect on systemic vascular resistance, myocardial perfusion pressure, or contractility. Atropine is indicated for the treatment of bradycardia associated with hypotension, second- and third-degree heart block, and slow idioventricular rhythms. Atropine is no longer recommended for asystole or PEA.

Should I worry about bradycardia?

Adults and children who have a low pulse and experience severe symptoms, such as chest pain or fainting, should also go to the hospital. A person should see a doctor for bradycardia when: they experience an unexplained change in heart rate that lasts for several days.

What happens if bradycardia is left untreated?

When bradycardia is more severe, you may experience shortness of breath, chest pain, and fainting. If severe bradycardia goes untreated, it could lead to cardiac arrest, meaning the heart stops beating, and that can lead to death.

Can you fix bradycardia naturally?

Take the following steps: Exercise and eat a healthy diet. Live a heart-healthy lifestyle by exercising regularly and eating a healthy, low-fat, low-salt, low-sugar diet that’s rich in fruits, vegetables and whole grains. Maintain a healthy weight.

What are symptoms of bradycardia?

This abnormally low heart rate can cause the brain and other organs to become oxygen-deprived, which can lead to symptoms such as:

  • Fainting.
  • Dizziness.
  • Fatigue.
  • Weakness.
  • Shortness of breath.
  • Chest pain.
  • Confusion.
  • Memory difficulties.

How fast do you give atropine?

Atropine should be administered by rapid IV push and may be repeated every 3-5 minutes, to a maximum dose of 3 mg. Atropine is ineffective and should be avoided in heart transplant patients.

What can bradycardia lead to?

Left untreated, severe or prolonged bradycardia can cause:

  • Heart failure.
  • Fainting (syncope)
  • Chest pain (angina pectoris)
  • Low blood pressure (hypotension)
  • High blood pressure (hypertension)

How is unstable bradycardia treated?

If the patient is symptomatic, administer atropine 1.0 mg IV or IO bolus and repeat the atropine every 3 to 5 minutes to a total dose of 3 mg: If atropine does not relieve the bradycardia, continue evaluating the patient to determine the underlying cause and consider transcutaneous pacing.

Can atropine cause bradycardia?

Background: Low-dose atropine causes bradycardia either by acting on the sinoatrial node or by its effects on central muscarinic receptors increasing vagal activity.

What happens if you take atropine?

Atropine causes the muscles in your eye to become relaxed. This widens (dilates) your pupil so that it will not respond to light. Atropine ophthalmic (for the eye) is used to dilate your pupils when you have an inflammatory condition or in postsurgery situations in which this effect may be helpful.