Tachycardia is a condition where the heart beats too fast. A healthy heart beats 60 to 100 times per minute, pumping about 300 litres of blood every hour. Exercise, stress or fear can cause the heat to beat faster, but this is a normal response. With tachycardia, the heart beats at more than 100 beats per minute and can beat as fast as 400 beats per minute for no specific reason. At this rate the heart is not able to pump blood effectively to the body and brain.
There are different types of fast heart rhythms that can occur in either the upper chambers (atria) or lower chambers (ventricles) of the heart.
Sudden Cardiac Arrest (SCA) is an electrical problem with the heart that triggers a dangerously fast heart rhythm (ventricular fibrillation). The rapid, irregular heart rhythm causes the heart to quiver rather than contract or pump. When the heart stops pumping blood, oxygen cannot reach the body or brain. If not treated immediately, SCA can be fatal.
Sudden Cardiac Arrest is leading cause of death in Australia claiming approximately 30,000 lives each year. That’s about one every 20 seconds and also 24 times greater than the amount of people who die in motor vehicle accidents.
Sudden cardiac arrest is not the same as a heart attack, although the two are often confused.
Heart Attack – A circulation or plumbing problem
Cause – Blockage in a vessel that supplied blood to the heart muscle, which may permanently damage part of the heart.
Risk Factors – High cholesterol, high blood pressure, obesity, smoking, family history of a heart attack, diabetes.
Symptoms – May be accompanied by pressure in the chest, pain radiating to the arm, shortness of breath, sweating, nausea.
Sudden Cardiac Arrest (SCA) – An electrical problem
Cause – Electrical malfunction of the heart that results in no blood flow to the body and brain.
Risk Factors – Previous heart attack, heart failure, abnormal heart rhythm, low ejection fraction, family history of SCA
Symptoms – Generally no symptoms, may experience racing heartbeat, lightheadedness, dizziness, fainting.
Generally, sudden cardiac arrest strikes without warning. People who are at a higher risk for SCA include:
EF stands for “ejection fraction.” It is the percentage of blood that is pumped out of the heart with each heartbeat. Your doctor determines how well your heart is pumping based on your EF number.
Your EF number can change over time. It is important for you and your doctor to check your EF regularly.
How is EF measured? The most common way to measure EF is with an echocardiogram. This test is usually performed in a doctor’s office or hospital diagnostic area.
|50-75%||Heart's pumping ability is normal|
|36-49%||Heart's pumping ability is below normal|
|35% & below||Heart's pumping ability is low|
The most effective way to treat SCA is through defibrillation. Defibrillation involves delivering an electrical shock to your heart to restore a normal heartbeat. To survive an SCA event you must receive defibrillation within 10 mintues. Only about 5% of people survive SCA, because defibrillation was not delivered within this critical time frame.
There are two primary forms of defibrillation:
An implantable defibrillator is designed to monitor your heart rhythm 24 hours a day. If your heart is beating too fast or irregularly, the device will first send small painless electrical signals to correct your heart rate. If the fast heart rate continues, the defibrillator will deliver a shock to restore your heart to a normal rate. The implantable defibrillator can also treat slow heart rhythms by sending electrical pulses to the heart to correct it.
The procedure to implant a defibrillator does not require open heart surgery, and most people go home within 24 hours. Before the surgery, medication may be given to make you sleepy and comfortable. Generally, the procedure is performed under local anesthesia.
The general steps of an implant procedure include:
Follow-up appointments enable the defibrillator to be thoroughly checked. During these check-ups your doctor can:
Can I use a mobile phone? - Yes. When talking on a mobile phone keep the phones antenna fifteen centimeters away from your implantable defibrillator, and use the phone on the ear opposite your implantable defibrillator. We also recommend you avoid placing the mobile phone in a pocket near your implantable defibrillator.
Are household appliances safe to use? - Yes. Most household appliances are safe to use as long as they are properly maintained and in good working order. This includes microwaves, ovens, major appliances, electric blankets, and heating pads.
Will magnets affect my device? - Items that contain magnets, such as magnetic therapy products, stereo speakers, and hand held massagers can temporarily affect the operation of your implantable defibrillator. Therefore, it is recommended you keep items containing magnets at least fifteen centimeters away from your implantable defibrillator. We do not recommend the use of magnetic mattress pads and pillows because it is difficult to maintain a fifteen centimeter distance when using these items.
Will I be able to travel? - Given the short duration of security screening, it is unlikely that your medtronic implantable defibrillator will be affected by metal detectors or full body imaging scanners such as those found in airports, courthouses and jails.
To minimise the temporary interference with your implantable defibrillator while going through the security screening process, avoid touching metal surfaces around any screening equipment. Do not stop or linger in a walk-through archway; simply walk through the archway at a normal pace. If a hand-held wand is used, ask the security operator not to hold it over your implantable defibrillator and not to wave it back and forth over your defibrillator. You may also request a hand search as an alternative.
Providing invasive & non-invasive cardiovascular services to patients in Far North Queensland, PNG, and the Torres Strait Islands