Causes of Fast Heart Rate and paroxysmal supraventricular tachycardia

Tachycardia: Fast Heart Rate

Tachycardia refers to a heart rate that’s too fast. How that’s defined may depend on your age and physical condition.
Generally speaking, for adults, a heart rate of more than 100 beats per minute (BPM) is considered too fast. 

A profile for atrial or SVT

In general, those most likely to have atrial or supraventricular tachycardia are:

• Children (SVT is the most common type of arrhythmia in kids)
• Women, to a greater degree than men
• Anxious young people
• People who are physically fatigued
• People who drink large amounts of coffee (or caffeinated substances)
• People who drink alcohol heavily
• People who smoke heavily

Atrial or SVT is less commonly associated with heart attack or serious mitral valve disease.

Episodes of faster-than-normal heart rate characterize paroxysmal supraventricular tachycardia (PSVT). PSVT is a fairly common type of abnormal heart rate. It can occur at any age and in people who don’t have other heart conditions.

The heart’s sinus node typically sends electrical signals to tell the heart muscle when to contract. In PSVT, an abnormal electrical pathway causes the heart to beat faster than normal. Episodes of rapid heart rate can last from a few minutes to several hours. A person with PSVT can have a heart rate as high as 250 beats per minute (bpm). A normal rate is between 60 and 100 bpm.

PSVT can cause uncomfortable symptoms, but it’s not usually life-threatening. Most people don’t need long-term treatment for PSVT. There are medications and procedures that may be necessary in some cases, especially where PSVT interferes with heart function.

The term “paroxysmal” means that it only happens from time to time.

What are the risk factors for paroxysmal supraventricular tachycardia?

PSVT affects about 1 in every 2,500 children. It is the most frequent abnormal heart rhythm in newborns and infants. Wolff-Parkinson-White syndrome (WPW) is the most common type of PSVT in children and infants.

PSVT is more common in adults under age 65. Adults over age 65 are more likely to have atrial fibrillation (AFib).

In a normal heart, the sinus node directs electrical signals through a specific pathway. This regulates the frequency of your heartbeats. An extra pathway, often present in supraventricular tachycardia, can lead to the abnormally fast heartbeat of PSVT.

There are certain medications that make PSVT more likely. For example, when taken in large doses, the heart medication digitalis (digoxin) can lead to episodes of PSVT. The following actions can also increase your risk of having an episode of PSVT:

    ingesting caffeine

    ingesting alcohol

    smoking

    using illegal drugs

    taking certain allergy and cough medications

What are the symptoms of paroxysmal supraventricular tachycardia?

The symptoms of PSVT resemble the symptoms of an anxiety attack and can include:

    heart palpitations

    a rapid pulse

    a feeling of tightness or pain in the chest

    anxiety

    shortness of breath

In more serious cases, PSVT can cause dizziness and even fainting due to poor blood flow to the brain.

Sometimes, a person experiencing symptoms of PSVT may confuse the condition with a heart attack. This is especially true if it’s their first PSVT episode. If your chest pain is severe you should always go to the emergency room for testing.

How is paroxysmal supraventricular tachycardia diagnosed?

If you have an episode of fast heartbeats during an examination, your doctor will be able to measure your heart rate. If it’s very high, they may suspect PSVT.

To diagnose PSVT, your doctor will order an electrocardiogram (EKG). This is an electrical tracing of the heart. It can help determine which type of rhythm problem is causing your fast heart rate. PSVT is only one of many causes of abnormally fast heartbeats. Your doctor will also likely order an echocardiogram, or ultrasound of the heart, to evaluate the size, movement, and structure of your heart.

If you have an abnormal heart rhythm or rate, your doctor may refer you to a specialist who is an expert in electrical problems of the heart. They are known as electrophysiologists or EP cardiologists. They may perform an electrophysiology study (EPS). This will involve threading wires through a vein in your groin and up into your heart. This will allow your doctor to evaluate your heart’s rhythm by checking the electrical pathways of your heart.

Your doctor may also monitor your heart rate over a period of time. In this case, you may wear a Holter monitor for 24 hours or longer. During that time, you’ll have sensors attached to your chest and will wear a small device that records your heart rate. Your doctor will assess the recordings to determine if you have PSVT or some other type of abnormal rhythm.

How is paroxysmal supraventricular tachycardia treated?

You might not need treatment if your symptoms are minimal or if you only have episodes of rapid heart rate occasionally. Treatment may be necessary if you have an underlying condition causing the PSVT or more severe symptoms like heart failure or passing out.

If you have a rapid heart rate but your symptoms aren’t severe, your doctor can show you techniques to return your heart rate to normal. It’s called the Valsalva maneuver. It involves closing your mouth and pinching your nose while trying to exhale and straining as if you were trying to have a bowel movement. You should do this while sitting and bending your body forward.

You can perform this maneuver at home. It may work up to 50 percent of the time. You can also try coughing while sitting and bending forward. Splashing ice water on your face is another technique to help lower your heart rate.

Treatments for PSVT include medications, such as or flecainide or propafenone, to help regulate your heartbeat. A procedure called radiofrequency catheter ablation is a common way to correct PSVT permanently. It’s performed in the same way as an EPS. It allows your doctor to use electrodes to disable the electrical pathway that’s causing the PSVT.

If your PSVT doesn’t respond to other treatments, your doctor may surgically implant a pacemaker into your chest to regulate your heart rate.

Things You Can Do for Rapid Heartbeat:

• Make sure you tell your doctor, as well as all healthcare providers, about any other medications you are taking (including over-the-counter, vitamins, or herbal remedies).  Do not take aspirin or products containing aspirin unless your healthcare provider permits this.
• Remind your doctor or healthcare provider if you have a history of diabetes, liver, kidney, or heart disease.
• If you have a family history of heart disease, stroke, high blood cholesterol, or high blood pressure, in a first or second-degree relative, you may be at risk for certain problems. Notify your healthcare provider if you have any of these diseases in your family.
• Smoking can cause palpitations and increased heart rate. If you smoke, be sure to quit. Smoking can also increase the chance of developing heart vessel damage.
• Caffeine and alcohol can cause palpitations and increased heart rate. Eliminate caffeine and alcohol from your diet, and your symptoms may resolve.
• Keep a diary of your increased heart rate, if it is occurring regularly. Write down the foods that you have eaten, the exercise or activity you were undergoing when the rapid or irregular heartbeats occurred, and how you felt before they occurred. This diary may be valuable in determining the cause of your symptoms.
• Questions to ask yourself, may include:
  • Did the increased heart rate occur gradually, or did this episode come on all of a sudden? Was I feeling anxious? Did I perform any kind of activity, or was I resting?
• Make sure to exercise, under the supervision of your healthcare provider. Walking, swimming, or light aerobic activity may decrease your resting heart rate, help you to lose weight, and promote the flow of oxygen in your lungs and blood.
• Use relaxation techniques to decrease the amount of anxiety you have. If you feel anxious, place yourself in a quiet environment, and close your eyes. Take slow, steady, deep breaths, and try to concentrate on things that have relaxed you in the past.
• If you are ordered a medication to treat this disorder, do not stop taking any medication unless your healthcare provider tells you to. Take the medication exactly as directed. Do not share your pills with anyone.
• If you miss a dose of your medication, discuss with your healthcare provider what you should do.
• If you experience symptoms or side effects, especially if severe, be sure to discuss them with your health care team.  They can prescribe medications and/or offer other suggestions that are effective in managing such problems.
• Keep all your appointments for your treatments.

Drugs That May Be Prescribed by Your Doctor:

• ACE inhibitors - These drugs work by opening, or dilating, your arteries. They will lower your blood pressure, and improve blood flow to your kidneys, and through out your body. Your healthcare provider may also prescribe these medications if you have diabetes or protein in your urine, to protect your kidneys. Some examples of this medication may include: Enalapril Maleate (Vasotec^®), Lisinopril (Zestril^®), and Fosinopril Sodium (Monopril^®)
• Antianxiety medications: If your increased heart rate is due to anxiety, your healthcare provider may prescribe an anti-anxiety medication, called an anxiolytic.  These medications will help you to relax. It is important to take these medications only when you are feeling anxious. Do not operate heavy machinery, or drive an automobile while taking these. If these medications do not control your symptoms, discuss this with your doctor.
• Beta-blockers - can be used to slow down your heart rate, and improve blood flow through your body. You may take this drug if you have been diagnosed with irregular heartbeats, or high blood pressure. Some examples of this medication may include: Metoprolol (Lopressor^®), propanolol (Inderal^®), and atenolol (Tenormin^®).
• Calcium Channel Blockers - These medications may be given to treat chest pain, high blood pressure, or irregular heart beats. This medication will slow your heart rate. A few common drugs include Verapamil HCL (Calan^®), and Diltiazem (Dilacor XR^®).
• Digoxin - Also called digitalis, this medication works by slowing down the heart rate, and making it beat more effectively. This will pump blood through out the body better. It is also called Lanoxin^®.
• Diuretics - may be known as "water pills", as they work to prevent heart failure by making you urinate out extra fluid. Some examples of this medication may include furosemide (Lasix^®), and Hydrochlorthiazide. You may receive this medication alone or in combination with other medications.
• Do not stop any of these medications abruptly, as serious side effects may occur.

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