- Electrocardiogram (ECG/EKG)
- Stress Test (TMT/ETT)
- 24 Hour Holter Monitoring
- 24 Hour Ambulatory Blood Pressure Monitoring (ABPM)
- Color & Doppler Echocardiography
- 4D Echocardiography
- Calcium Scoring-128 Slice Cardiac-CT
- Cardiac CT Angiogram -128 Slice Ultra fast Non-invasive Cardiac-CT
- Cardiologist’s consultation
An electrocardiogram is used to monitor your heart. Each beat of your heart is triggered by an electrical impulse normally generated from special cells in the upper right chamber of your heart. An electrocardiogram — also called an ECG or EKG — records these electrical signals as they travel through your heart. Your doctor can use an ECG to look for patterns among these heartbeats and rhythms to diagnose various heart conditions.
An ECG is a noninvasive, painless test. The results of your electrocardiogram will likely be reported the same day it’s performed, and your doctor will discuss them with you at your next appointment.
Why it’s done
An electrocardiogram is a painless, noninvasive way to diagnose many common types of heart problems. Your doctor may use an electrocardiogram to detect:
- Irregularities in your heart rhythm (arrhythmias)
- Heart defects
- Problems with your heart’s valves
- Blocked or narrowed arteries in your heart (coronary artery disease)
- A heart attack, in emergency situations
- A previous heart attack
An electrocardiogram is a safe procedure. There may be minor discomfort, similar to removing a bandage, when the electrodes taped to your chest to measure your heart’s electrical signals are removed. Rarely, a reaction to the electrodes may cause redness or swelling of the skin.
A stress test, in which an ECG is performed while you exercise or after you take medication that mimics effects of exercise, may cause irregular heartbeats or, rarely, a heart attack. These side effects are caused by the exercise or medication, not the ECG itself.
There isn’t any risk of electrocution during an electrocardiogram. The electrodes placed on your body only record the electrical activity of your heart. They don’t emit electricity.
How you prepare
No special preparations are necessary. However, avoid drinking cold water or exercising immediately before an electrocardiogram. Cold water can produce potentially misleading changes in one of the electrical patterns recorded during the test. Physical activity, such as climbing stairs, may increase your heart rate.
What you can expect
An electrocardiogram can be done in the doctor’s office or hospital, and is often performed by a technician. After changing into a hospital gown, you’ll lie on an examining table or bed. Electrodes, often 12 will be attached to your arms, legs and chest. The electrodes are sticky patches applied with a gel to help detect and conduct the electrical currents of your heart. If you have hair on the parts of your body where the electrodes will be placed, the technician may need to shave the hair so that the electrodes stick properly.
You can breathe normally during the electrocardiogram. Make sure you’re warm and ready to lie still, however. Moving, talking or shivering may distort the test results. A standard ECG takes just a few minutes.
If you have a heartbeat irregularity that tends to come and go, it may not be captured during the few minutes a standard ECG is recording. To work around this problem, your doctor may recommend another type of ECG:
- Holter monitoring – also known as an ambulatory ECG monitor, a Holter monitor records your heart rhythms for an entire 24-hour period. Wires from electrodes on your chest go to a battery-operated recording device carried in your pocket or worn on a belt or shoulder strap. While you’re wearing the monitor, you’ll keep a diary of your activities and symptoms. Your doctor will compare the diary with the electrical recordings to try to figure out the cause of your symptoms.
- Event recorder – if your symptoms don’t occur often, your doctor may suggest wearing an event recorder. This device is similar to a Holter monitor, but it allows you to record your heart rhythm just when the symptoms are happening. You can send the ECG readings to your doctor through your phone line.
- Stress test – if your heart problems occur most often during exercise, your doctor may ask you to walk on a treadmill or ride a stationary bike during an ECG. This is called a stress test. If you have a medical condition that makes it difficult for you to walk, medication may be injected to mimic the effect of exercise on the heart.
After the procedure
Usually, your doctor will be able to tell you the results of your ECG the same day it’s performed. If your electrocardiogram is normal, you may not need any other tests. If the results show there’s a problem with your heart, you may need a repeat ECG or other diagnostic tests, such as an echocardiogram. Treatment depends on what’s causing your signs and symptoms.
Your doctor will look for a consistent, even heart rhythm and a heart rate between 60 and 100 beats a minute. Having a faster, slower or irregular heartbeat provides clues about your heart health, including:
- Heart rate – Normally, heart rate can be measured by checking your pulse. But an ECG may be helpful if your pulse is difficult to feel or too fast or too irregular to count accurately.
- Heart rhythm – An ECG can help your doctor identify an unusually fast heart beat (tachycardia), unusually slow heart beat (bradycardia) or other heart rhythm irregularities (arrhythmias). These conditions may occur when any part of the heart’s electrical system malfunctions. In other cases, medications, such as beta blockers, psychotropic drugs or amphetamines, can trigger arrhythmias.
- Heart attack – An ECG can often show evidence of a previous heart attack or one that’s in progress. The patterns on the ECG may indicate which part of your heart has been damaged, as well as the extent of the damage.
- Inadequate blood and oxygen supply to the heart – An ECG done while you’re having symptoms can help your doctor determine whether chest pain is caused by reduced blood flow to the heart muscle, such as with the chest pain of unstable angina.
- Structural abnormalities – An ECG can provide clues about enlargement of the chambers or walls of the heart, heart defects and other heart problems.
Stress Test (TMT/ETT)
Exercise testing is a cardiovascular stress test that uses treadmill bicycle exercise with electrocardiography (ECG) and blood pressure monitoring. Pharmacologic stress testing, established after exercise testing, is a diagnostic procedure in which cardiovascular stress induced by pharmacologic agents is demonstrated in patients with decreased functional capacity or in patients who cannot exercise. Pharmacologic stress testing is used in combination with imaging modalities such as radionuclide imaging and echocardiography.
Exercise stress testing, which is now widely available at a relatively low cost, is currently used most frequently-
- to estimate prognosis and determine functional capacity,
- to assess the probability and extent of coronary disease, and
- to assess the effects of therapy.
Ancillary techniques, such as metabolic gas analysis, radionuclide imaging (see the images below), and echocardiography, can provide further information that may be needed in selected patients, such as those with moderate or prior risk.
Normal radionuclide uptake (dipyridamole-CardiolitNormal radionuclide uptake (dipyridamole-Cardiolite). Normal wall motion with radionuclide uptake. Normal wall motion with radionuclide uptake.
Cardiovascular exercise stress testing in conjunction with ECG has been established as one of the focal points in the diagnosis and prognosis of cardiovascular disease, specifically coronary artery disease (CAD).
The initiation of dynamic exercise results in increases in ventricular heart rate, stroke volume, and cardiac output as a result of vagal withdrawal and sympathetic stimulation. Alveolar ventilation and venous return also increase as a consequence of sympathetic vasoconstriction. The overall hemodynamic response depends on the amount of muscle mass involved, exercise efficiency, conditioning, and exercise intensity.
In the initial phases of exercise in the upright position, cardiac output is increased by an augmentation in stroke volume mediated through the use of the Frank-Starling mechanism and heart rate. The increase in cardiac output in the later phases of exercise is due primarily to an increase in ventricular rate. During strenuous exertion, sympathetic discharge is maximal and parasympathetic stimulation is withdrawn, resulting in autoregulation with generalized vasoconstriction, except in the vital organs (cerebral and coronary circulations).
Release of venous and arterial norepinephrine from sympathetic postganglionic nerve endings is increased, and epinephrine levels are increased at peak exertion, resulting in a rise in ventricular contractility. As exercise progresses, skeletal muscle blood flow increases; oxygen extraction increases as much as 3-fold; peripheral resistance decreases; and systolic blood pressure (SBP), mean arterial pressure, and pulse pressure usually increase. Diastolic blood pressure (DBP) remains unchanged or may increase or decrease by approximately 10 mm Hg.
The pulmonary vascular bed can accommodate as much as a 6-fold increase in cardiac output, with only modest increases in pulmonary arterial pressure, pulmonary capillary wedge pressure, and right atrial pressure; this is not a limiting determinant of peak exercise capacity in healthy subjects.
Maximum heart rate and cardiac output are decreased in older individuals, in part because of decreased beta-adrenergic responsiveness. Maximum heart rate can be calculated by subtracting the patient’s age (in years) from 220 (standard deviation, 10-12 beats/min).
The age-predicted maximum heart rate is a useful measurement for safety purposes and for estimating the adequacy of the stress to evoke inducible ischemia. A patient who reaches 80% of the age-predicted maximum is considered to have a good test result, and an age-predicted maximum of 90% or better is considered excellent.
In the post-exercise phase, hemodynamics return to baseline within minutes after exercise is discontinued. The return of vagal stimulation is an important cardiac deceleration mechanism after exercise; it is more pronounced in well-trained athletes but is blunted in patients with chronic congestive heart failure.
Intense physical work or important cardiorespiratory impairment may interfere with achievement of a steady state, and an oxygen deficit occurs during exercise. The oxygen debt is the total oxygen uptake in excess of the resting oxygen uptake during the recovery period.
Indications and Contraindications
Treadmill stress testing is indicated for diagnosis and prognosis of cardiovascular disease, specifically CAD. Contraindications have been outlined in guidelines from the American College of Cardiology (ACC) and the American Heart Association (AHA).
Absolute contraindications include the following:
- Acute myocardial infarction (MI; within 2 days)
- Unstable angina not previously stabilized by medical therapy – Appropriate timing of tests depends on the level of risk of unstable angina as defined by the Agency for Health Care Policy and Research Unstable Angina Guidelines
- Uncontrolled cardiac arrhythmias causing symptoms or hemodynamic compromise
- Symptomatic severe aortic stenosis
- Uncontrolled symptomatic heart failure
- Acute pulmonary embolus or pulmonary infarction
- Acute myocarditis or pericarditis
- Acute aortic dissection
Relative contraindications can be superseded if the benefits of exercise outweigh the risks. They include the following:
- Left main coronary stenosis
- Moderate stenotic valvular heart disease
- Electrolyte abnormalities
- Severe arterial hypertension – In the absence of definite evidence, the committee suggests an SBP higher than 200 mm Hg, a DBP higher than 110 mm Hg, or both
- Tachyarrhythmia or bradyarrhythmias
- Hypertrophic Cardiomyopathy and any other forms of outflow tract obstruction
- Mental or physical impairment leading to an inability to exercise adequately
- High-degree atrioventricular (AV) block
The vast majority of treadmill exercise tests are performed on adults with symptoms of known or probable ischemic heart disease. Candidates for exercise stress testing may have stable symptoms of chest pain, may be stabilized by medical therapy after experiencing symptoms of unstable chest pain, or may have already had an MI or undergone a vascularization procedure.
The clinical suggestion of CAD on the basis of patient history findings, ECG tracings, and symptoms of chest pain must be established and used as a guide to determine if treadmill exercise testing may be useful according to the Bayes theorem, which states that the diagnostic power of exercise stress testing is maximal when the pretest probability of CAD is intermediate (30-70%) as indicated by age, sex, and nature of chest pain.
When the diagnosis of CAD is confirmed on the basis of age, sex, description of chest pain, and history of previous MI, a clinical need may arise for risk or prognostic assessment to reach a decision regarding possible coronary angiography or revascularization to guide further medical management.
MI (see the images below) is a common first presentation of ischemic heart disease. This subset of patients also may require prognostic or risk assessment.
Inferior-wall myocardial infarct and fixed defect.Inferior-wall myocardial infarct and fixed defect. Motion abnormalities in inferior wall consistent wMotion abnormalities in inferior wall consistent with inferior-wall myocardial infarction. Inferobasal fixed defect and lateral wall ischemiaInferobasal fixed defect and lateral wall ischemia. Wall motion abnormalities in inferobasal region. Wall motion abnormalities in inferobasal region.
Chest pain is a common presentation to both general practitioners and A&E departments. Often one of the main differentials is cardiac chest pain and ruling this out in patients who might be otherwise well or only have one or two cardiac risk factors, can be difficult. Exercise tolerance testing (ETT) or stress test is one method which is used to determine the presence of significant coronary heart disease.
ETT has been quoted as having a sensitivity of 78% and a specificity of 70% in detecting coronary artery disease. Thus, a negative test may not necessarily be true and further testing or advice may be warranted. Diagnostic accuracy is also poor in women and this may relate to smaller heart size. For this reason, ETT is being superseded by cardiac imaging techniques, such as myocardial perfusion scans, in some centers. Even so, ETT can be valuable when performed in selected patients and the following criteria have been suggested:
- Ability to exercise.
- Normal baseline 12-lead ECG.
- No previous cardiac revascularization.
Indications for exercise tolerance testing
- Diagnosis of coronary heart disease (keeping in mind the high number of false positives and false negatives).
- Assessment of ‘fitness’ in certain occupations and medical conditions, e.g. the police force and some cardiomyopathies.
- Arrhythmias – ETT can help to record arrhythmias which are provoked by exercise (but only in those with non-life-threatening arrhythmias).
What the exercise tolerance test involves
- ETT consists of exercising on a treadmill following a defined protocol, the Bruce protocol, over approximately 20 minutes. The test begins gently and gradually the level of intensity is increased through a combination of increased treadmill speed and incline.
- Intensity of exercise is measured in in METs where 1 MET (metabolic equivalent) is the amount of energy expended at rest or 3.5 ml oxygen per kilogram per minute.
- The test is divided into seven stages of three minutes and there is also a less strenuous version called the modified Bruce.
- ECG is recorded throughout and blood pressure measured intermittently.
- ETT might be prematurely stopped for any of the following: development of chest pain, presence of ST elevation, very deep ST depression, arrhythmias, and hypotension or if the patient becomes tired and is unable to continue. In addition, elevation of blood pressure to dangerous levels such as >170/120 mm Hg should also lead to termination of the test.
- Beta-blockers and digoxin can interfere with the results so are usually stopped before the ETT.
Contra-indications to exercise tolerance testing
- Chest pain at rest or at night.
- Any condition where left ventricular output is reduced, eg aortic stenosis or hypertrophic obstructive cardiomyopathy (HOCM).
- Active systemic illness.
- Abnormal baseline ECG, eg bundle branch block patterns or left ventricular hypertrophy – these make interpretation of the ETT difficult.
- Suspected or confirmed life-threatening arrhythmias.
Interpreting the exercise tolerance test
- ST elevation – usually this will be picked up straightaway and dealt with.
- The patient is normally considered to have been adequately ‘stressed’ if they achieve 85% or more of their maximum heart rate (calculated as 220 – age in years for men and 210 – age for women). However, recent data suggest that using these criteria to terminate the test may lead to an underestimation of inducible ischaemia.
- At each stage each lead should be examined for:
- Planar ST depression (this can be difficult to delineate from depression of the J point, which is the point where the QRS complex meets the ST wave).
- ‘Flipping’ of the T waves.
- Examination of all leads should continue into the recovery stage after the exercise stage of the test has been completed.
These are rare but can be fatal, eg myocardial infarction, left ventricular rupture, ventricular fibrillation or ventricular tachycardia.
Following up an abnormal exercise tolerance test
- Referral to cardiologists if an adequate ETT was undertaken and is abnormal.
- If an inadequate test was performed, further non-invasive investigations may be indicated, such as myocardial perfusion scanning, cardiac MRI, or stress echocardiogram. These are usually requested by the cardiologists, so a referral or discussion may be needed.
In recent years major advances in 4D echocardiography have been made and many new and most promising tools, like 4D Strain and 4D TEE have been introduced to the echo lab.
Those innovations have impacted productivity and workflow positively and have led in many institutions to improved clinical confidence in the day-by-day diagnostic work. It is the aim of the International Academy of Medical Ultrasound to provide courses to physicians to familiarize them with those latest developments in echocardiography.
Calcium Scoring-128 Slice Cardiac-CT
A coronary calcium scan is a test that looks for specks of calcium in the walls of the coronary (heart) arteries. These specks of calcium are called calcifications.
Calcifications in the coronary arteries are an early sign of coronary heart disease (CHD). CHD is a disease in which a waxy substance called plaque builds up in the coronary arteries.
Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart. This can cause chest pain or discomfort called angina.
If the plaque ruptures, a blood clot can form on its surface. A large blood clot can mostly or completely block blood flow through a coronary artery. This is the most common cause of a heart attack. Over time, ruptured plaque also hardens and narrows the coronary arteries.
CHD also can lead to heart failure and arrhythmias. Heart failure is a condition in which your heart can’t pump enough blood to meet your body’s needs. Arrhythmias are problems with the rate or rhythm of your heartbeat.
Two machines can show calcium in the coronary arteries—electron beam computed tomography (EBCT) and multidetector computed tomography (MDCT).
Both use x rays to create detailed pictures of your heart. Your doctor will study the pictures to see whether you’re at risk for future heart problems.
A coronary calcium scan is a fairly simple test. You’ll lie quietly in the scanner machine for about 10 minutes while it takes pictures of your heart. The pictures will show whether you have calcifications in your coronary arteries.
Coronary Calcium Scan
Figure A shows the position of the heart in the body and the location and angle of the coronary calcium scan image. Figure B is a coronary calcium scan image showing calcifications in a coronary artery.
Because calcifications are an early sign of CHD, a coronary calcium scan can show whether you’re at risk for a heart attack or other heart problems before other signs and symptoms occur.
A coronary calcium scan is most useful for people who are at moderate risk for heart attacks. You or your doctor can calculate your 10-year risk using the Risk Assessment Tool from the National Cholesterol Education Program.
People who are at moderate risk have a 10–20 percent chance of having a heart attack within the next 10 years. The coronary calcium scan may help doctors decide who within this group needs treatment.
Cardiac CT Angiogram -128 Slice Ultra fast Non-invasive Cardiac-CT
A computerized tomography (CT) coronary angiogram is an imaging test to look at the arteries that supply your heart muscle with blood. Unlike a traditional coronary angiogram, CT angiograms don’t use a catheter threaded through your blood vessels to your heart. Instead, a coronary CT angiogram relies on a powerful X-ray machine to produce images of your heart and heart vessels. CT angiograms don’t require the recovery time needed with traditional angiograms. Coronary CT angiograms are becoming a common option for people with a variety of heart conditions.
CT angiograms will expose you to a small amount of radiation. If you have known coronary artery disease, a traditional coronary angiogram may be a better option, since you can also receive treatment for your artery blockages during a traditional coronary angiogram.
Why it’s done
A coronary CT angiogram is a test that can check your heart for various conditions, but it’s primarily used to check for narrowed arteries in your heart (coronary artery disease) that could explain chest pain or could put you at risk of a heart attack.
Coronary CT angiograms are sometimes used in place of traditional coronary angiograms to check for coronary artery disease. A CT angiogram may be better than a traditional angiogram for people who have only a moderate risk of coronary artery disease.
Typically, when your doctor needs to check for blockages in your heart’s arteries, he or she will perform a coronary angiogram. In a coronary angiogram, a catheter is inserted in an artery in your groin and threaded through your blood vessels to your heart. Dye that’s visible on X-rays is then injected through the catheter, and X-ray images of your heart are taken. Your doctor can see blockages in your heart’s arteries on the images. Because the catheter is near your heart, if blockages are found, your doctor can perform a procedure called angioplasty to open your blockages after a traditional angiogram.
In a CT angiogram, no catheter has to be placed in your groin, and the dye that’s visible on the CT scan is injected through an intravenous (IV) line that’s placed in your hand or arm. X-ray images are still taken of your heart. However, because no catheter is used, if a blockage in your heart’s arteries is found, you’ll need a separate procedure (a traditional coronary angiogram) to treat your condition.
A test that’s similar to CT angiogram is a coronary calcium scan. This test uses a special type of computerized tomography to check for calcium in your coronary arteries, which can be a risk factor for coronary artery disease. No dye is injected during a coronary calcium scan.
Because CT angiograms use an X-ray machine to take pictures of your heart, you will be exposed to some radiation during the test. The amount of radiation varies depending on the type of machine used. With the most common type of X-ray machines, the radiation you’re exposed to during the test is about the same as the average American is naturally exposed to over three years. The risk that you could develop cancer from the radiation you receive during a CT angiogram is not known exactly, but is very small.
Because radiation can harm an unborn child, you shouldn’t have a CT angiogram if you’re pregnant.
It’s also possible that you could have an allergic reaction to the dye used in the procedure. Talk to your doctor if you’re concerned about having an allergic reaction.
How you prepare
Your doctor should give you instructions about how to prepare for your CT angiogram. Usually, you’ll be asked not to eat anything for four to eight hours before your test. You can drink water, but avoid caffeinated drinks before your test, because they can speed up your heart rate. This can make it difficult for your doctor to get clear pictures of your heart.
You can drive yourself to the appointment, and you’ll be able to drive home or to work after your test.
What you can expect
CT angiograms are usually performed in the radiology department of a hospital or an outpatient clinic.
Just before you begin your scan, you’ll need to remove clothing above your waist, as well as any jewelry. You’ll change into a hospital gown.
Because your heart’s constantly in motion while it beats, your doctor may give you a medication called a beta blocker, which will slow your heart rate. This will allow the doctor to see your heart more clearly. A technician will insert an intravenous (IV) line in your hand or arm to inject the dye that will make your heart’s arteries visible on the images taken by the CT scanner. You’ll receive some numbing medication before the IV is inserted. Although the actual scanning portion of the test takes less than 15 seconds, it may take up to an hour for the beta blocker to slow your heart rate sufficiently before the CT angiogram begins.
The technician will place some electrodes on your chest to record your heart rate throughout the exam. When you’re ready to be scanned, you’ll lie on a long table that slides through a short, doughnut-like machine. During the test, an X-ray tube will move rapidly around your chest to take images of your heart from many different angles. You won’t see the tube moving. A technician will operate the machine from a room that’s separated from your exam room by a glass window. There will be an intercom system the technician can use to talk to you.
It’s important to stay as still as possible and hold your breath during the scanning portion of the exam. Any movement can blur the X-ray images.
After the procedure
After your CT angiogram is completed, you can return to your normal daily activities. You should be able to drive yourself home or to work.
The images from your CT angiogram should be ready soon after your test. Either the doctor who performed your test or the doctor who asked you to have a CT angiogram should discuss the results of the test with you.
Based on the results of your test, your doctor will discuss with you whether you have a heart condition that needs treatment, whether you’re at risk of developing heart disease, and steps you can take to keep your heart healthy. Treatments may vary, depending on what condition your doctor suspects you have.
Regardless of the results of your test, it’s a good idea to make lifestyle changes to help protect your heart. These include:
- Exercise regularly – Exercise helps you reach and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure — all risk factors for heart disease. With your doctor’s OK, aim for 30 to 60 minutes of physical activity most days of the week. Even if you can’t make time for one 30- to 60-minute exercise session, you can still benefit from breaking up your activity into several 10-minute sessions.
- Eat healthy foods – A heart-healthy diet based on fruits, vegetables and whole grains — and low in saturated fat, cholesterol and sodium — can help you control your weight, blood pressure and cholesterol. Eating one or two servings of fish a week also is beneficial.
- Stop smoking – Smoking is a major risk factor for heart disease, especially atherosclerosis. Nicotine constricts blood vessels and forces your heart to work harder, and carbon monoxide reduces oxygen in your blood and damages the lining of your blood vessels. If you smoke, quitting is the best way to reduce your risk of heart disease and its complications.