This is All You'll Ever Need to Know About Tachycardia
Tachycardia is a fast-resting heart rate of
usually at least 100 beats per minute. This can be a dangerous
condition, depending on its underlying cause and how hard the heart has
to work.
Normally, the adult resting heart, beats between 60-100 beats per minute. However, when an individual has
tachycardia, the upper and/or lower chambers of the heart beat a lot
faster. Our heart rates are controlled by electrical signals that are
sent across the heart’s tissues.
When the heart starts producing rapid
electrical signals, tachycardia occurs.
When the heart is beating too fast, it cannot pump efficiently, and
blood flow to the rest of the body, including the heart, reduces. Since
the heart is beating quicker, the myocardium (muscles of the heart) need
more oxygen – if they become oxygen-starved, they will start to die
off, leading to a heart attack.
Some patients with this condition show no symptoms or complications.
However, tachycardia significantly increases the possibility of a
stroke, sudden cardiac arrest, and death.
Symptoms of Tachycardia
Accelerated heart rate (fast pulse)
• Chest pain
• Confusion
• Dizziness
• Hypotension
• Panting
• Sudden weakness
• Lightheadedness
• Palpitations – an uncomfortable racing feeling in the chest
Treatments for Tachycardia
Treatment options for this condition vary, depending on what has caused
the condition, and the patient’s age and general health. The aim of the
treatment is to tackle the cause of the tachycardia. When clinically
applicable, the doctor may attempt to slow the rate, prevent subsequent
episodes of tachycardia, and reduce risk complications. However, when no
underlying cause is found, the doctors will have to try out different
therapies.
Ways to Slow Down a Fast Heartbeat
Vagal Maneuvers
The vagal nerve helps to regulate our heartbeat. Maneuvers that affect
this nerve include coughing, heaving, and placing an ice pack on your
face.
Medication
Antiarrhythmic drugs that help to restore and control a normal heartbeat
can be taken orally or by injection. Sometimes a patient might have to
take more than one kind of antiarrhythmic drug.
Cardioversion
Paddles or patches are used to deliver electric shocks to the heart.
This affects the electrical impulses in the heart and helps to restore a
normal rhythm. This is done in a hospital.
Prevention of Episodes of Tachycardia
Radio-frequency Catheter Ablation
Catheters enter the heart via blood vessels. Then, electrodes at the
ends of the catheters are heated to ablate (damage) the sections of the
heart that are responsible for the abnormal heart rate.
Medications
When taken regularly, antiarrhythmic medications can help prevent
tachycardia. However, patients may be required to take other medications
as well, such as channel blockers, or example diltiazem (Cardizem) and
verapamil (Calan), or beta-blockers, for example, propranolol (Inderal),
and esmolol (Brevibloc).
Implantable Cardioverter Defibrillator
(ICD)
This device, which constantly monitors the patient’s heartbeat, is
surgically implanted into the chest. The ICD detects any heart
abnormalities and delivers shocks to keep the heart rate normal.
Surgery
Sometimes, surgery is needed to remove a section of tissue. This
procedure is only carried out when other therapies have been
ineffective, or if the patient has another heart disorder.
Warfarin
This makes it harder for the blood to clot and it’s given to patients
with a high or moderate risk of having a stroke or heart attack.
Although this drug increases the risk of bleeding, it is prescribed to
those whose risk of a stroke or heart attack far outweighs the risk of
bleeding.
Causes of Tachycardia
A reaction to certain medications
• Congenital (present at birth) electrical pathway abnormalities in the
heart
• Consuming too much alcohol
• Consumption of cocaine and other recreational drugs
• Electrolyte imbalance
• Heart disease which has resulted in poor blood supply and damage to
heart tissue, including heart valve disease, coronary artery disease,
heart failure, heart muscle disease, infections, or tumors.
• Hypertension
• Hyperthyroidism (overactive thyroid gland)
• Smoking
• Certain lung diseases
Types of Tachycardia
Atrial Fibrillation
Sometimes, electrical activity can arise from the left atrium instead of
the sinus node. This causes the chambers to contract at a high and
irregular rate; this is atrial fibrillation. An episode of atrial
fibrillation can last from a few hours to several days, and sometimes it
may not go away until treated.
Atrial Flutter
The atria beat rapidly, but regularly. This condition is caused by a
circuit problem within the right atrium. The contractions of the atria
are weak because of the rapid heartbeat. An atrial flutter episode can
last a few hours or a few days. It may also not go away until treatment
is received. This is often caused by some form of heart disease.
Supraventricular Tachycardias (SVTs)
This refers to any tachycardic (accelerated) heart rhythm that
originates above the ventricular tissue. The abnormal circuitry in the
heart is usually congenital (present a birth) and creates a loop of
overlapping electrical signals. An SVT episode can last from anywhere
between a few seconds to a few hours.
Ventricular Tachycardia
Abnormal electrical signals in the ventricles result in a rapid heart
rate. The speed of the heartbeat does not allow the ventricles to
contract and fill properly, leading to poor blood supply to the body.
This type of tachycardia is life-threatening and is usually treated as a
medical emergency.
Ventricular Fibrillation
This occurs when the ventricles quiver in an ineffective way, resulting
in poor blood supply to the body. If a normal heartbeat is not restored
rapidly, blood circulation will cease, and the patient will die. Those
with an underlying heart condition, or those who have been hit by
lightning, may experience ventricular fibrillation.
Risk Factors for Tachycardia
• Age – people aged 60 and above have a much higher chance of
experiencing tachycardia
• Anxiety
• Consuming large quantities of alcohol regularly
• Consuming large quantities of caffeine
• Genetics – people who have close relatives with tachycardia or other
heart rhythm disorders have a higher chance of developing the condition
• Heart disease
• Hypertension (high blood pressure)
• Mental stress
• Smoking
• Using recreational drugs
Diagnosis of Tachycardia
A doctor can usually diagnose tachycardia by asking the patient some
questions about their symptoms, carrying out a physical exam, and
ordering some tests to be done. These may include:
Electrocardiogram
Electrodes are attached to the patient’s body to measure the electrical
pulses that are given off by the heart. This test is also able to show
any previous heart disease that may have contributed to the tachycardia.
Echocardiogram
This is a type of ultrasound investigation. By bouncing sounds of the
structures in the body and registering the echoes, a moving image of the
heart can be produced. This can help show structural or congenital
abnormalities that might be playing a role in tachycardia.
Holter Monitor
The patient wears a portable device that records their heartbeat. It’s
worn under the clothing and records information about the electrical
activity of the heart while the person goes about their daily
activities.
Blood Tests
This will help determine whether thyroid problems or other substances
may be contributing to the patient’s tachycardia.
Tilt-Table Test
If the patient is experiencing fainting spells, lightheadedness, or
dizziness, and neither the ECG or the Holter revealed any arrhythmias, a
tilt-table test will be performed. This monitors the patient’s blood
pressure, heart rhythm, and heart rate while they are moved from a lying
to an upright position.
Chest X-Ray
This helps the doctor to check the state of the individual’s heart and
lungs. Other conditions that could be causing the tachycardia might also
be detected.
Possible Complications of Tachycardia
• Blood clots – these significantly increase the risk of a heart attack
or stroke
• Heart failure – if the condition isn’t controlled, the heart is likely
to get weaker. Heart failure is when the heart does not pump blood
around the body efficiently or properly. The patients left, right, or
even both sides can be affected.
• Fainting spells
• Sudden death – generally only linked to ventricular tachycardia or
ventricular fibrillation.