Cardiac Positron Emission Tomography (PET)

Positron emission tomography (PET) is a scan that uses information about the energy of certain elements in your body to show whether parts of the heart muscle are alive and working. A PET scan can also show if your heart is getting enough blood to keep the muscle healthy. A PET scan is very accurate because it actually shows your heart at work.

Echocardiography

Echocardiography (or Echocardiogram) — A diagnostic method in which a hand-held device is placed on the chest and high-frequency sound waves (ultrasound) are used to produce images of the heart’s size, structure and motion. An “echo” provides valuable information about the health of the heart and helps gather information about abnormal rhythms (arrhythmias).

Electrocardiography (EKG or ECG)

Electrocardiogram (or Electrocardiography, ECG or EKG) — A quick, painless test that records the electrical activity of the heart. It may be taken at rest or during exercise. It is the standard clinical tool for diagnosing arrhythmias (abnormal rhythms) and to check if the heart is getting enough blood or if areas of the heart are abnormally thick. Small patches called electrodes are placed on different parts of the body. Different tracings of the heart's electrical activity can be made and permanently recorded on paper or in a computer. Three major waves of electric signals appear on the ECG. Each one shows a different part of the heartbeat. The P wave records the electrical activity of the atria. The QRS wave records the electrical activity of the ventricles, and the T wave records the heart's return to the resting state. Doctors study the shape and size of the waves, the time between waves and the rate and regularity of beating. This tells a lot about the heart and its rhythm.

Exercise Stress Testing

A stress test, sometimes called a treadmill test or exercise test, helps a doctor find out how well your heart handles work. As your body works harder during the test, it requires more oxygen, so the heart must pump more blood. The test can show if the blood supply is reduced in the arteries that supply the heart. It also helps doctors know the kind and level of exercise appropriate for a patient.

A person taking the test

•   is hooked up to equipment to monitor the heart.
•   walks slowly in place on a treadmill. Then the speed is increased for a faster pace and the treadmill is tilted to produce the effect of going up a small hill.
•   can stop the test at any time if needed.
•   afterwards will sit or lie down to have their heart and blood pressure checked.

Heart rate, breathing, blood pressure, electrocardiogram (e-lek"tro-KAR'de-o-gram) (ECG or EKG), and how tired you feel are monitored during the test.

Healthy people who take the test are at very little risk. It's about the same as if they walk fast or jog up a big hill. Medical professionals should be present in case something unusual happens during the test.

A physician may recommend an exercise stress test for various reasons:

•   To diagnose coronary artery disease
•   To diagnose a possible heart-related cause of symptoms such as chest pain, shortness of breath or lightheadedness
•   To determine a safe level of exercise
•   To check the effectiveness of procedures done to improve coronary artery circulation in patients with coronary artery disease
•   To predict risk of dangerous heart-related conditions such as a heart attack.

Depending on the results of the exercise stress test, the physician may recommend more tests such as a nuclear stress test or cardiac catheterization. 

History of illness

The cardiac work-up of a heart patient begins with a series of questions during which important information is gathered. This may cover some, or all, of the following areas:

Chief or predominant complaint
Other heart related complaints
Past illness or history
Family history
Review of systems or non-cardiac complaints
Social history

CHIEF COMPLAINT:

This medical evaluation of a person with suspected heart disease begins with an interview about the patient's major or "chief " complaint. The physician begins the process by asking specific questions about the complaint. For example, if the patient presents with chest pain, the physician will inquire about the character, location, severity and duration of the pain. What brought it on? What relieved it? Did it move to the shoulder, arms, jaw, back or other parts of the body? Were there associated symptoms like shortness of breath, sweating, dizziness, weakness, nausea, vomiting, etc.? When did it first start? How often does it occur? If it was initially brought on by exertion, is the pattern changing? Is it brought on by lesser amounts of exertion? Is it becoming more frequent with time? Are the symptoms lasting longer? Do they appear at rest or has it awakened the patient from a sound sleep? Answers to these questions are analyzed by the physician and help him or her determine the cause of the pain and the seriousness of the problem.

Other cardiac chief complaints can consist of shortness of breath, dizziness, blackout spells, palpitations (a sensation of skipped, forceful, or fast heartbeats), weakness, swelling of the legs, etc. Each of these will prompt a series of specific questions that will help the physician arrive at a preliminary single diagnosis, or a group of different diagnoses. The latter is known as a "differential diagnosis" A HISTORY obtained by a physician is similar to a detective interviewing a victim. The goal is to identify the criminal (disease) that is responsible for the victim's (patient's) problem.

Holter/Event/Transtelephonic Monitoring

Holter Monitors
The Holter monitor, invented by Dr. Norman Holter, is a device that records the heart rhythm continuously for 24 hours.  This means that it records each and every heart beat over that time.  Sticky patches (electrodes) on the chest are connected to wires from the Holter monitor.  The monitor is carried with the patient for the recording period.  The heart rhythm is recorded onto a cassette tape or flash card technology and then processed at a heart center.  From this recording, a wide variety of information can be obtained including heart rates during day and night, abnormal heart beats, and recording of rhythm during any symptoms during the recording.  A diary comes with the Holter for the patient or caregiver to write down the time and type of symptoms so the rhythm can be reviewed.

Figure 1. Holter monitor with four leads and solid state recording. Other monitors may have up to seven leads and run on cassette tapes.

Figure 2. 

Event Monitors
Event monitors are small devices that are used by patients over a longer period (weeks to months, typically one month).  Two sticky patches (electrodes) on the chest connect two wires to the event recorder.  The monitor is always on but will only store the patient’s rhythm when the patient or caregiver pushes the button.  Most monitors will save the rhythm for several seconds of rhythm before the button is even pushed.  The rhythm is also saved for a period after the button is pushed.  A few specialized monitors are used only after the patient has symptoms.  The intent is for most event monitors to be worn as much as possible every day to increase the chances of recording the patient’s rhythm when he/she has symptoms.

Once a recording (sometimes more than one) has been made, it can be transmitted over the phone back to your heart center.

Figure 2. Event monitor with leads.  Some devices will store more that one event.

Transtelephonic monitors
These small devices transmit the patient’s rhythm live over the phone.  These devices do not save a recording of rhythm for later playback like an event monitor.  The transtelephonic devices are commonly used by pacemaker/ICD patients for routine scheduled checks over the phone. (An ICD is an implantable cardioverter-defibrillator or shock device used for treating life-threatening rhythm problems.)

Transtelephonic monitor used with pacemaker patients.  Each wristband is a lead that is worn by the patient during transmission of the rhythm.  The white round magnet is used by some pacemaker patients to transmit specific data about the pacemaker. 

Implantable Loop Recorders (ILRs)
Some patients have serious but very infrequent symptoms that can't be recorded by regular event recorders because they occur so rarely.  In these cases, it may become necessary to implant a special event recorder called an ILR under the patient’s skin.  An ILR is the size of an adult’s little finger.  It is implanted under the skin by a one-inch incision on the chest.  The battery lasts 14 months.  It is always watching the patient’s rhythm.  It will make a recording of the patient’s rhythm when either the patient places an activator over the ILR and pushes a button when they are having a symptom or when the patient’s rate goes above or below the limits set in the ILR.  The recordings cannot be sent over the phone.  Instead, a programmer machine reads the information with radio waves.  The ILR will store up to 14 events between each reading.

Do they hurt or are they harmful?
The Holter monitor, event monitor and transtelephonic monitors do not hurt.   They do not cause any harm because they're recording devices.  They do not send out electricity. The ILR requires a small surgical incision that causes minimal discomfort for a few days.  After that, there is no pain.

Is there anything else to know about these devices?
The Holter, event and transtelephonic monitors cannot get wet or they will become damaged.  The ILR is protected by the skin so bathing and swimming with an ILR is fine after the wound has healed.  The ILR will need to be removed when it is no longer needed.  This is usually when the reason for the infrequent symptoms has been determined.

Nuclear Cardiology

Coronary artery disease is the leading cause of death in the United States.  Exercise testing and nuclear scanning are common tools that are used to diagnose the presence of obstructions in the coronary vessels and to evaluate their severity.

“Nuclear cardiology helps your cardiologist get detailed information about your heart through the use of safe, radioactive drugs, usually thallium. During a nuclear test, your heart is "exercised" either on a treadmill or with medications. Then, a small amount of thallium is injected into the bloodstream and its movement is traced by a special nuclear imaging camera. (See photo above) Thallium flows freely through normal arteries and less so through narrowed arteries.

Pacemaker/Internal Cardiac Defibrillator (ICD) Clinic

An implantable cardioverter defibrillator (ICD) is a small device that's placed in your chest or abdomen. The device uses electrical pulses or shocks to help control life-threatening, irregular heartbeats, especially those that could cause sudden cardiac arrest (SCA).

Physical examination

After obtaining a history, the physician proceeds to perform a physical examination. Depending upon the patient's condition and suspected medical problem, a physician may include one or more of the following four phases of the physical examination:

Inspection
Palpation or "hands-on" examination
Percussion or "tapping" examination
Auscultation or use of stethoscope

Inspection: During this portion of the examination, the physician inspects or looks at different parts of the patient's body. For example, while inspecting the eyes, the physician could obtain a clue about an overactive thyroid that could be responsible for the patient's rapid heart beat. A characteristic growth on the eyelids could point to a high cholesterol level that is a risk factor for coronary artery disease.

Inspection of the neck veins and its prominence could be indicative of heart failure and an excessive load on the right side of the heart. A bluish discoloration of the tongue and nail beds could point to a low oxygen level in the blood, while pallor or a pale appearance could indicate a low level of hemoglobin.  Additionally, inspection of the chest may provide information about enlargement of the heart. Thus, a physician obtains an enormous amount of information even before touching the patient.