Procedures

WHAT IS AN ANGIOGRAM
An angiogram is an examination of your blood vessels using x-rays. The doctor will insert a small tube (catheter) into the blood vessel and then he/she will inject x-ray dye (contrast) that makes the vessels visible when the x-ray pictures are being taken. This will then allow the doctor to determine how well the blood moves through the vessels of your brain, lung, abdomen, arms or legs. 

WHY DO I NEED AN ANGIOGRAM?
You need an angiogram because your doctor suspects there is abnormal blood flow in one or more of your vessels. By injecting contract through a catheter into your vessels and taking x-ray pictures, the radiologist is able to see if there is a problem and help your doctor plan a method of treatment for you. 

WHAT HAPPENS WHEN I GET TO THE X-RAY ROOM?
In the x-ray room you will see lots of special equipment. The staff will position you on the x-ray table and begin to prepare you for the procedure. This includes monitoring your heart and blood pressure. If you don't already have an IV (intravenous line), the nurse will start one so that you can receive fluids and medications during the procedure. 

WHAT IS AN ANGIOGRAM LIKE? 

Catheter insertion: The staff will clean your skin with cold soap where the doctor will place the catheter. This is usually at the top of the leg (groin) or the wrist. You will then be covered with a sterile sheet. Next, the nurse will give you medications in your IV to relieve the pain and allow you to relax. The doctor will then use a small needle to numb your skin where the catheter will be inserted.. You may feel pressure or brief discomfort as the catheter goes in. The doctor will guide the catheter through the body to the vessel that is to be studied by watching it on a TV-like monitor. You will not feel the catheter moving through your blood vessels. 

Taking x-ray pictures: Once the catheter is in the correct vessel, contrast will be injected through the catheter while x-ray pictures are being taken. You may feel hot inside when the contrast is injected, but the sensation only lasts a few seconds. Several series of contrast injections and x-ray pictures may be needed to complete the examination. 

Removal of the catheter: When the angiogram is completed, the doctor will remove the catheter from your blood vessel. He/she will apply pressure for 10-15 minutes over the catheter site to prevent bleeding. A band-aid will be placed on the insertion site. The angiogram usually takes one or more hours to complete. The radiology staff will always be nearby to keep you comfortable and answer any questions you may have. 

HOW DO I GET READY FOR MY ANGIOGRAM?
It is important that you do not eat or drink anything after midnight before your exam. You may have a small amount of water or another clear liquid with any medications you need to take. Be sure to ask your doctor if you have any questions about eating or drinking before your exam. If you are allergic to X-ray dye, iodine, or shellfish, it is important to let your doctor know as soon as possible. You will be asked to sign a special form giving the doctor permission to perform the angiogram. Everyone having an angiogram will have blood tests done prior to the procedure. Your groin will also be shaved on one or both sides where the doctor will insert the catheter. You will be asked to put on a hospital gown. 

This is typically performed in the same setting as the angiogram (cardiac catheterization), if a significant blockage is identified. Percutaneous transluminal coronary angioplasty (PTCA), or angioplasty, and Percutaneous Coronary Intervention (PCI) are invasive procedures performed to reduce or eliminate blockages in coronary arteries. -The goal of PTCA/PCI is to restore blood flow to blood-deprived heart tissue, reduce the need for medication, and eliminate or reduce the number of episodes of angina (chest pain). 

Opening a blockage, or a plaque, in a coronary artery typically involves the use of an angioplasty balloon. In most cases, a stent is implanted after angioplasty to keep the artery open and prevent restenosis (re-growth of plaque). 

The arteries are accessed through a needle puncture made in the groin (femoral artery) or wrist (radial artery). Usually the femoral artery is used. 

More than one blockage can be treated during a single session, depending on the location of the blockages and the patient's condition. The procedure can take 30 minutes to several hours, depending on the number of blockages being treated. 

Indications
PCI is recommended for patients with one or more of the following symptoms:
Blockage (stenosis) of one or more coronary arteries, Angina not well controlled with medications, Angina that disrupts daily activities, occurs at rest (i.e., without exercise or exertion), or recurs after heart attack. 

Merced Heart Associates is pleased to announce that it now offers the latest diagnostic imaging technology, positron emission tomography, or PET imaging, for heart disease patients. Merced Heart Associates offers the only dedicated cardiac PET in Merced, Madera, and Stanislaus Counties. PET imaging is a powerful modality that enables physicians to detect and diagnose coronary artery disease quickly and accurately. 

Merced Heart Associates has always been a leader in patient care. The addition of PET imaging will make a profound difference in patients' lives. Not only can we detect heart disease earlier and more accurately, we can learn more quickly whether treatments are working or need to be altered. 

PET studies are convenient and easy for the patient. Scanning begins following the injection of the PET tracer Rubidium 82 which is rapidly taken up by heart muscle cells following the injection. While lying on a comfortable table, the patient moves through the scanner to obtain images of the heart. The entire procedure usually takes 45 minutes. This is compared to the 4-6 hours for single photon emission computed tomography (SPECT). 

SPECT has been our only means of performing nuclear myocardial perfusion imaging (MPI) studies until the introduction of our cardiac PET program (September 2010). While SPECT can serve as an effective tool for many patients, PET offers unique advantages that can be especially beneficial for difficult to image patients. PET reduces the potential for attenuation artifacts seen with SPECT imaging, particularly in patients with a significant amount of additional soft tissue (obese, BMI >30, and large breasted women). PET imaging is performed at a fraction of the radiation exposure of SPECT with a much higher accuracy of disease detection (90-95% sensitivity and 95% specificity).

Patients who would especially benefit from PET MPI: 

• Those who require pharmacologic stress testing 
• Obese (BMI>30) 
• Female (especially patients with large breasts) 
• Patients likely to have multi-vessel disease 
• Patients who have had an equivocal SPECT MPI study 

Cardiolite scans (Cardiolite is the trade name for Sestamibi) are tests that show how well blood is flowing to various portions of the heart muscle. These tests, which are varieties of nuclear perform studies, are generally used in conjunction with stress tests to non-invasively diagnose the presence of coronary artery disease. 

What is Cardiolite?
Cardiolite are radioactive substances. When injected into the bloodstream, these substances collect in the portions of heart muscle that have good blood flow. If one of the coronary arteries (the arteries that supply blood to the heart muscle) is blocked or partially blocked, not as much Cardiolite accumulates in the muscle supplied by that blocked artery. 

How are nuclear perfusion studies performed?
During a stress test, Cardiolite is injected into the patient's vein when the maximum level of exercise is reached. The radioactive substance distributes itself throughout the cardiac muscle in proportion to the blood flow received by that muscle. Cardiac muscle receiving normal blood flow accumulates a larger amount of Cardiolite than cardiac muscle that is supplied by diseased coronary arteries. An image of the heart is then made by a special camera that can "see" the Cardiolite. From these pictures, portions of the heart that are not receiving normal blood flow (because of the blockage in the coronary arteries) can be identified. 

What are nuclear perfusion studies good for?
Using Cardiolite perfusion imaging greatly increases the accuracy of the stress test in diagnosing coronary artery disease. A normal Cardiolite test is an excellent indication that the patient has no significant coronary artery disease. Patients with abnormal perfusion scans are highly likely to have significant coronary artery disease. 

What are the risks of nuclear perfusion scans?
These non-invasive studies are very safe. Their only drawback is that radiation is used – but the patient is exposed only to about the same amount of radiation as for a chest x-ray. 

What is it used for?
The ECG is the most commonly performed cardiac test. This is because of the ECG is a useful screening tool for a variety of cardiac abnormalities; ECG machines are readily available in most medical facilities; and the test is simple to perform, risk-free and inexpensive. 

How is the ECG performed?
The patient lies on an examination table, and 10 electrodes (or leads) are attached to the patient's arms, legs, and chest. The electrodes detect the electrical impulses generated by the heart, and transmit them to the ECG machine. The ECG machine produces a graph (the ECG tracing) of those cardiac electrical impulses. The electrodes are then removed. The test takes less than 5 minutes to perform. 

What information can be gained from the ECG?
From the ECG tracing, the following information can be determined:
The heart rate, the heart rhythm, whether there are conduction abnormalities, whether there has been a prior heart attack, whether there may be coronary artery disease, whether the heart muscle has become abnormally thickened. 

All of these features are potentially important. If the ECG indicates a heart attack or possible coronary artery disease, further testing is often done to completely define the nature of the problem and decide on the optimal therapy. If the heart muscle is thickened, an echocardiogram is often ordered to look for possible valvular heart disease or other structural abnormalities. Conduction abnormalities may be a clue to the diagnosis of syncope (fainting), or may indicate underlying cardiac disease. 

Echocardiogram is an extremely useful test for studying the heart's anatomy. It is non-invasive and entirely safe, and when interpreted by well-trained cardiologists, is very accurate. 

How is the echocardiogram performed?
The patient lies on a bed or examination table, and the echo technician places a transducer (a device that resembles a computer mouse) over the chest wall. The transducer is moved back and forth across the chest wall, collecting several "views" of the heart. The test takes approximately 30 minutes to complete. 

How does the echocardiogram work?
The transducer placed on the chest sends sound waves toward the heart. Like the sonar on a submarine, the sound waves bounce off the cardiac structures (that is, they "echo" of the heart). The sound wave "echoes" are collected by the transducer. These returning sound waves are computer-processed, and an image of the beating heart is produced on a television screen. By "aiming" the transducer, most of the important cardiac structures can be imaged by the echocardiogram. 

What are some of the variations used with the echocardiogram?
Echocardiograms are sometimes used in conjunction with stress tests. An echo test is made at rest, and then with exercise, looking for changes in the function of the heart muscle when exercise is performed. Deterioration in muscle function during exercise can indicate coronary artery disease. 

A Doppler microphone can be used during echocardiography to measure the velocity of blood flow in the heart. This information can be useful in assessing heart valve function.
 

What is the echocardiogram good for?
The echocardiogram reveals important information about the anatomy of the heart. It is especially useful for detecting problems with the heart valves. It is also an extremely useful test for evaluating congenital heart disease. The echocardiogram is also a good way to get a general idea of the overall function of the heart muscle. 

What are pacemakers supposed to accomplish?
A pacemaker is a sophisticated electronic device that does two things: 1) It analyzes the function of the heart's own electrical system. 2) When necessary, it sends tiny, precisely-timed electrical signals to the heart, to correct certain abnormalities in the heart's electrical system. Most pacemakers are designed to correct the bradycardias (the slow ones). Abnormally slow heart rhythms can cause weakness, fatigue, lightheadedness, dizziness, loss of consciousness, or even death. Pacemakers, properly used, effectively eliminate all of these symptoms. 

Pacemakers consist of two major parts: the generator and the leads. 

The generator is essentially a tiny, hermetically sealed computer – along with a battery to run it – housed in a titanium container. Most modern pacemaker generators are roughly the size of a 50-cent piece, and approximately three times as thick. The battery life of most pacemaker generators today is 8-10 years. 

The lead is a flexible insulated electrical wire. One end is attached to the generator and the other end is passed through a vein in the heart. Most pacemakers today use 2 leads – one placed in the right atrium and the other in the right ventricle. 

How it works: The pacemaker leads detect the heart's own electrical activity (in the right atrium and right ventricle,) and transmit that information to the pacemaker generator. The generator – which, again, is a computer – analyzes the heart's electrical signals, and uses that information to decide whether, when, and where to pace. If the heart rate becomes too slow, the generator transmits a tiny electrical signal to the heart, thus stimulating the heart muscle to contract. (This is called pacing.) Pacemakers that have two leads not only keep the heart rate from dropping too low, they can also maintain the optimal coordination between the atria and the ventricles (by pacing the atrium and the ventricle in sequence.) 

Thus, pacemakers do not take over the work of the heart – the heart still does its own beating – but instead, pacemakers merely help to regulate the timing of the heart beat.
 

What devices can interfere with pacemakers?
Home appliances do not interfere with pacemakers, and should not cause any concern whatsoever. (This includes microwave ovens, despite the signs you still see posted in some restaurants). 

Arc welding equipment and other devices that generate powerful magnetic fields can inhibit the function of pacemakers. 

MRI scanners can interrupt the pacing function of pacemakers. This problem can often be circumvented by special programming of the pacemaker. 

Radiation therapy for cancers can damage the circuits of a pacemaker, and the pacemaker needs to be shielded from the radiation field. 

A defibrillator performs the same functions as a pacemaker, but is also able to shock your heart when necessary to restore your cardiac rhythm.  It is typically indicated for those who have congestive heart failure because they are more likely to have fatal arrhythmias.  A defibrillator is a bit larger than a pacemaker because of the larger battery required to shock the heart if needed.  The procedure for implantation is very similar to a pacemaker. 

Exercise Stress Testing for the Heart
Some forms of cardiac disease are easily missed when the patient is at rest, because at rest the patient's physical examination and ECG are often entirely normal. In these cases, cardiac abnormalities may become apparent only when the heart is asked to perform at increased workloads. The stress test is used to evaluate the heart and vascular system during exercise. It helps answer to two general questions: 1) Is there occult underlying heart disease that only becomes apparent when the heart is stressed by exercise? 2) If there is underlying heart disease, how severe is it? 

How is a stress test performed?
The patient is attached to an ECG machine, and a blood pressure cuff is placed on one arm. Sometimes a clothespin-like sensor is attached to the finger to measure the amount of oxygen in the blood. After a baseline ECG is obtained, the patient begins to perform a low level of exercise, either by walking on a treadmill, or pedaling a stationary bicycle. The exercise is "graded" – that is, every three minutes, the level of exercise is increased. At each "stage" of exercise, the pulse, blood pressure and ECG are recorded, along with any symptoms the patient may be experiencing. 

With a "maximal" stress test, the level of exercise is gradually increased until the patient cannot keep up any longer because of fatigue, or until symptoms (chest pain, shortness of breath, or lightheadedness) prevent further exercise, or until changes on the ECG indicate a cardiac problem. Maximal stress tests should be performed when the goal is to diagnose the presence or absence of coronary artery disease. With a "submaximal" stress test, the patient exercises only until a pre-determined level of exercise is attained. These tests are used tin patients with known coronary artery disease to measure whether a specific level of exercise can be performed safely. After the test, the patient remains monitored until any symptoms disappear, and until the pulse, blood pressure and ECG return to baseline. 

What are the risks of having a stress test?
The stress test has proven to be remarkably safe. It poses about the same level of risk as taking a brisk walk or walking up a hill. While it is possible that the ischemia provoked by such stress can lead to a myocardial infarction (heart attack) or to serious heart rhythm disturbances, in practice this event is rare. Further, when these serious events do occur during a stress test, they occur in the presence of trained medical personnel who can deal with them immediately. 

What is an electrical cardioversion?
Cardioversion is a brief procedure where an electrical shock is delivered to the heart to convert an abnormal heart rhythm back to a normal rhythm. Most elective or "non-emergency" cardioversions are performed to treat atrial fibrillation or atrial flutter, benign heart rhythm disturbances originating in the upper chambers (atria) of the heart. Cardioversion is used in emergency situations to correct a rapid abnormal rhythm associated with faintness, low blood pressure, chest pain, difficulty breathing or loss of consciousness. 

Why do I need a cardioversion?
Each normal heartbeat starts in an area of the heart known as the sinus node which is located in the upper right chamber of the heart (right atria). The sinus node contains specialized cells that send an organized electrical signal through the heart resulting in a perfectly timed, rhythmic heartbeat. In patients with atrial fibrillation, however, the atria fibrillate (or "quiver") due to chaotic electrical signals that circulate throughout both aria. This typically results in a fast and irregular heartbeat. While some patients have no symptoms, others may experience shortness of breath, lightheadedness and fatigue. 

Electrical cardioversion is a procedure whereby a synchronized (perfectly timed) electrical shock is delivered through the chest wall to the heart through special electrodes or paddles that are applied to the skin of the chest and back. The goal of the cardioversion is to disrupt the abnormal electrical circuit(s) in the heart and to restore a normal heartbeat. The shock causes all the heart cells to contract simultaneously, thereby interrupting, thereby interrupting and terminating the abnormal electrical rhythm (typically fibrillation of the atria) without damaging the heart. This split second interruption of the abnormal beat allows the heart's electrical system to regain control and restore a normal heartbeat. 

An electrical cardioversion is performed in a hospital setting. A cardiologist, a nurse and/or an anesthesiologist are present to monitor your breathing, blood pressure and heart rhythm. Special cardioversion pads are placed on your chest and back (or alternatively, both pads can be placed on the front of the chest). The pads are connected to an external defibrillator by a cable. The defibrillator allows the medical team to continuously monitor your heart rhythm and to deliver the electrical shock to restore your heart's rhythm back to normal. 

When the heart is not beating in a nice, smooth rhythm, the irregular beats it produces are called arrhythmias. When the heart is beating more than 100 times per minute, this type of arrhythmia is called tachycardia, a potentially dangerous condition. Ablation is a procedure to destroy very small, carefully selected parts of the heart that are causing tachycardia. As a result, the heart's normal, regular rhythm is restored. 

A nonsurgical method of ablation involves inserting a thin tube (catheter) through a blood vessel (in the upper thigh, wrist or arm) and all the way up to the heart. At the tip of the tube is a small wire, which can delivery radiofrequency energy to burn away the abnormal areas of the heart. With a success rate over 90 percent, radiofrequency ablation has become the preferred technique for treating tachycardia. 

Depending on the underlying arrhythmia, there still may be a need for antiarrhythmic medications. Patients with atrial fibrillation or ventricular tachycardia, for example, may require continued antiarrhythmics. The type and severity of an arrhythmia may also require more invasive surgery in order to correct the problem. 

What is a Holter Monitor?
Holter monitoring is a continual monitoring of heart rate and rhythm during your usual daily activities over a predetermined length of time, usually a 24-hour period.

Why this test may be performed?
A Holter monitor is used to identify heart rhythm disturbances, which may come and go at various times throughout the day or night. It is often used to correlate any abnormal heart rhythm with a person's symptoms, like dizziness, palpitations, shortness of breath or chest pain. 

What this test involves?
Electrodes are placed on the front of the chest and the electrode wires are then attached to a small portable, battery-operated recorder. The recorder is held in place by a belt that can be worn around the wait. The recorder continuously records and stores the heart rhythm for 24 hours. The person is encouraged to continue their usual daily activities. During this time period, the person wearing the device maintains a written log. Symptoms (for example, palpitations, dizziness, and shortness of breath) are written in the log, noting the exact activity and time they occur. Once the monitor has been removed, a physician analyzes the heart rhythm and activity log. 

What are the risks/precautions for this test?
A Holter monitor is a non-invasive test. It is painless and not associated with any risks to the patient. It is advisable to shower or bathe before the electrodes are applied to the chest, since you will not be able to do either of these activities while the test is in progress. 

What the results may tell you?
A Holter monitor may detect a disturbance in heart rhythm that is not evident on a single, resting electrocardiogram tracing. It allows the physician to correlate specific patient symptoms with the electrical activity of the heart. A Holter monitor can detect rhythm disturbances that are transient or intermittent in nature. 

What is a cardiac event monitor?
A cardiac event monitor is a small recorder that records your heart electrical activity – similar to a holter monitor but for a longer period of time. 

Why do I need a cardiac event monitor?
Event monitors help your doctor to diagnose problems that don't happen often enough for an EKG or Holter monitor to record. They are very useful to your doctor in diagnosing problems with your heart rhythm (arrhythmias) that happen infrequently. 

Using The Cardiac Event Monitor
The electrodes are attached to your chest and connected by wires to the recorder. Worn day and night, the recorder continuously scans your heart's electrical activity. When you experience symptoms, you notate them on the recorder by pressing a button. The device records and stores several minutes of EKG data before, during and after an event. Then you transmit the stored data to a receiving center, who transfers the information to your doctor. 

How often do I need to come to the office for my pacemaker check?
Most cardiologists recommend that your pacemaker be checked in the office every 3 to 6 months. 

Why should I come to the office for a pacemaker check?
In the office, we can do a more in-depth analysis of your pacemaker than is possible with telephone monitoring. This type of in-depth check can help prolong the life of your pacemaker battery. 

What happens in the clinic when I come to have my pacemaker checked?
Our staff will record the electrical activity of both your heart and your pacemaker. We will then evaluate how your pacemaker is functioning and its battery life. Depending on our findings, we may reprogram your pacemaker to make sure it is meeting your needs or to prolong the life of the battery. 

Who does the pacemaker check?
Your pacemaker will be checked or interrogated by an expert technician from the pacemaker company. 

How do I set up an appointment for the clinic?
The clinics are scheduled every Tuesday. Call our office at (209) 383-3456 and ask to speak with a receptionist to schedule a pacemaker check.