Beating Heart Surgery is better

Electrocardiogram

electrocardiogram

An electrocardiogram or ECG (also called an EKG) is a common, painless test that records the electrical activity of the heart and converts it into lines called “waveforms” that can be seen on a monitor or printed out on paper. The waveforms created by the ECG can be divided into time segments to measure the rate of movement of the heart’s electrical impulses.

An ECG can tell if the heart is beating normally or detect heart disease or problems with the electrical conduction system of the heart. It records the rate and regularity of heartbeats, can tell the size and position of the chambers of the heart. An ECG also can record signs of damage to the heart and the effects of drugs or devices such as pacemakers and ICDs.

How The Test Is Performed

An ECG is a safe, commonly performed heart test that rarely causes discomfort. The patient lies down and “electrodes” at the end of wires (or leads) are attached to each arm, leg and the chest. Electrodes are sticky patches that attach to the skin, or suction cups applied with conductive paste that are easily peeled off once the procedure is completed. There are no needles used and the test is painless. The ECG takes about ten minutes from start to finish, but the actual recording of the heart’s electrical activity usually is done in a matter of seconds. The places where the electrodes are attached are cleaned, and in some cases, it may be necessary to shave or clip the hair. Patients are required to remain still, and are sometimes asked to hold their breath for short periods of time.

How To Prepare For The Test

There is little preparation necessary for an ECG, and you may eat or drink fluids before and after the test. You may be asked to wear a hospital gown for the test, and all jewelry should be removed. Also, be sure to tell your doctor or the person who performs the ECG if you are taking any medications. Some medications can affect the electrical activity of the heart, and this information is important in order for the doctor to interpret the exam correctly.

An ECG May Be Performed to Identify:

• The cause of abnormal heart rhythms (arrhythmias) which may be caused by electrical signals that are too slow, too fast, or do not follow the normal path of conduction through the heart.
• Heart muscle damage.
• A decrease in oxygen supply to parts of the heart.
• Signs of a recent or prior heart attack, or myocardial infarction (MI). Sometimes, an ECG warns of an evolving MI.
• Whether a pacemaker or ICD is functioning appropriately.
• The effects of medications, specifically antiarrythmic drugs.

The 12-Lead ECG

The most common type of ECG is called a 12-lead ECG. In this test, 12 electrodes are attached to the skin of the arms, legs and chest to give 12 different views of the heart as electrical impulses travel through the muscle. Each of 12 views created by the ECG is shown in a short segment on the printed ECG report generated by the ECG machine. Often, a longer reading of one of the 12 views is printed out on a “rhythm strip.”

A Rhythm ECG

A bedside monitor that performs electrocardiography is called a rhythm ECG, which usually has from one to three electrodes. This is used when patients are hospitalized and require monitoring of the heart for an extended period of time.

How an ECG is Recorded

ECG Recording

Electrophysiology  Study

	Highly trained specialists perform EP studies in a specially designed EP lab outfitted with advanced technology and equipment.

Normally, electricity flows throughout the heart in a regular, measured pattern. This electrical system brings about heart muscle contractions. A problem anywhere along the electrical pathway causes an arrhythmia, or heart rhythm disturbance. By accurately diagnosing the precise cause of an arrhythmia, it is possible to select the best possible treatment.

Why an EP study

While electrocardiograms (ECGs) are important tests of the heart’s electrical system, they are brief tests that record only the events that occur while the tests are running. Arrhythmias, by their very nature, are unpredictable and intermittent, which makes it unlikely that an ECG or electrocardiogram will capture the underlying electrical pathway problem. Even tests that stretch over longer time lengths, such as Holter monitoring, may not capture an event.

During an EP study, a specially trained cardiac specialist may provoke arrhythmia events and collect data about the flow of electricity during actual events. As a result, EP studies can help locate the specific areas heart tissue that give rise to the abnormal electrical impulses that cause arrhythmias. This detailed electrical flow information provides valuable diagnostic and, therefore, treatment information.

EP studies most often are recommended for patients with symptoms indicative of heart rhythm disorders or for people who may be at risk for Sudden Cardiac Death.

THE VALUE OF AN EP STUDY

An electrophysiologic, or EP, study provides information that is key to diagnosing and treating arrhythmias. Although it is more invasive than an electrocardiogram (ECG) or echocardiogram, and involves provoking arrhythmias, the test produces data that makes it possible to:

• Diagnose the source of arrhythmia symptoms
• Evaluate the effectiveness of certain medications in controlling the heart rhythm disorder
• Predict the risk of a future cardiac event, such as Sudden Cardiac Death
• Assess the need for an implantable device (a pacemaker or ICD) or treatment procedure (radio frequency catheter ablation)
  

An overview of the procedure

While ECGs are non-invasive, an EP study is somewhat invasive. The study is performed after giving local anesthesia and conscious sedation (twilight sleep) to keep the patient as comfortable as possible. The procedure involves inserting a catheter – a narrow, flexible tube – attached to electricitymonitoring electrodes, into a blood vessel, often through a site in the groin or neck, and winding the catheter wire up into the heart. The journey from entry point to heart muscle is navigated by images created by a fluoroscope, an x-ray-like machine that provides continuous, “live” images of the catheter and heart muscle. Once the catheter reaches the heart, electrodes at its tip gather data and a variety of electrical measurements are made. These data pinpoint the location of the faulty electrical site. During this “electrical mapping,” the cardiac arrhythmia specialist, an electrophysiologist, may instigate, through pacing (the use of tiny electrical impulses), some of the very arrhythmias that are the crux of the problem. The events are safe, given the range of experts and resources close at hand and are necessary to ensure the precise location of the problematic tissue.

Once the damaged site or sites are confirmed, the specialist may administer different medications or electrical impulses to determine their ability to halt the arrhythmia and restore normal heart rhythm. Based on this data, as well as information garnered before the study, sometimes the specialist will proceed to place an implantable cardioverter device (ICD) or a pacemaker or will perform radiofrequency ablation. In any case, the information proves useful for diagnosis and treatment.

Throughout the procedure, the patient is sedated but awake and remains still. Patients rarely report pain, more often describing what they feel as discomfort. Some watch the procedure on monitors and occasionally ask questions. Others sleep. The procedure usually takes about two hours. The patient remains still for four to six hours afterward to ensure the entry point incision begins to heal properly. Once mobile again, patients may feel stiff and achy from lying still for hours.

THE IMPORTANCE OF THE FLOW OF ELECTRICITY

Each heart has it own normal rhythm brought about by the seamless flow of electrical impulses throughout the organ. This electrical flow begins in the heart’s natural “pacemaker” (also know as the sinoatrial node or sinus node) in the upper right heart chamber, the right atrium. The electricity flows through the upper chambers (atria), crosses the bridge between upper and lower chambers (atrioventricular node) and travels to the lower chambers (ventricles.) The passage of electricity culminates in a carefully coordinated contraction of heart muscle that pushes blood through the human body. Problems in the precise flow of electricity are the cause of arrhythmias.

Who performs the test and where

Since potentially dangerous arrhythmias are provoked during an EP study, it’s crucial that specialized staff are present to handle all situations. A physician electrophysiologist, with advanced training in the diagnosis and treatment of heart rhythm problems, performs the EP study. The electrophysiologist leads a team of specially trained health care professionals, technicians and nurses, who assist during the procedure. The team performs the EP study in an electrophysiology laboratory, or EP lab, a well-equipped, controlled clinical environment usually located within a hospital or clinic. As a result, the test is quite safe and complications are rare.

Cardiac Electrophysiology at CARE Hospitals INDIA Hyderabad

Cardiac Electrophysiology Hospitals INDIA