A holter monitor or ambulatory electrocardiography device is a portable equipment that is used to monitor electrical activity of the heart. There are a series of electrodes attached to the chest of the patient that can record electrical signals from the heart. There is a recording monitor that can be carried in the pocket or worn around the neck. The patient's EKG for 24 hours is recorded. Values such as average heart rate, maximum and minimum heart rate are calculated. ECG tracing using Holter monitor is conducted on patients who suffer prolonged fatigue and episodes of low blood pressure and fainting.
A Holter monitor aids in recording any abnormal activity of the heart. The Holter monitor is worn by the patient as he/she goes about his daily routine. It is possible to observe occasional cardiac arrhythmia, atrial fibrillation and atrial tachycardia with a Holter monitor. This device is also advised for patients who have suffered a heart attack or under cardiac medication. A Holter monitor aids in monitoring the performance of a heart pacemaker. Smoking and close proximity to devices such as magnets and metal detectors and some electrical appliances can affect the Holter monitor readings.
Cardiac Stress Test
A cardiac stress test aids in assessing how the heart can cope during exercise, especially when the body need for oxygen puts extra demands on the heart. A cardiac stress test is called a graded test or exercise tolerance test, exercise stress test or exercise electrocardiography. It helps to primarily evaluate the heart and vascular systems during the exercise. In fact, the American Heart Association has recommended the Cardiac stress test (EKG treadmill in particular) as the first choice to be tried on patients with medium risk of coronary heart disease and who exhibit certain risk factors of smoking, family history of coronary stenosis, high blood pressure, and high cholesterol.
- It helps to determine whether coronary arteries are clogged or blocked.
- To find the cause of chest pain.
- To assess the heart's capability after a heart attack or heart surgery.
- To discover the presence of any heart disease.
- To set limits on a person's exercise.
- To detect arrhythmia, that is extra heart beats, during the exercise.
- To assess the capacity of medicine used to control chest pain or extra beats during exercise.
The cardiac stress test can be done in a clinic or a hospital. The patient may be asked to exercise using a bicycle, treadmill or arm ergometer. The patient is attached to an ECG machine. The blood pressure cuff is placed on any one arm. The patient's heart is usually monitored using a 12 - lead EKG or ECG machine. A heart monitor may be used during and after exercise. After a baseline ECG is obtained, the patient begins to perform a low level of exercise, either by walking on a treadmill or pedaling on a stationary bicycle.
At each stage of the exercise, the pulse, the blood pressure and ECG are recorded along with any symptoms that the patient may be experiencing.
The level of exercise is gradually increased until the patient cannot keep up any longer because of fatigue or until symptoms like chest pain, shortness of breath or lightheadedness prevent further exercise. The goal of this stress test is to diagnose the presence or absence of coronary artery disease. In a sub maximal stress test, the patient exercises only until a pre-determined level of exercise is attained. These tests are used in patients with known coronary artery disease, to measure whether the patient can perform a specific level of exercise with relative safety.
The side effects of a cardiac stress test also include palpitation, chest pain, and shortness of breath, headache, nausea and fatigue. The hypertension caused by stress testing is always considered abnormal and it may lead to severe coronary disease. In stress tests, false positive results are not uncommon. There can be occasions when the patient's ECG changes could suggest ischemia, even in the absence of coronary artery disease. Similarly, in stress test, false negatives are also not uncommon. In some patients, no significant ECG changes will be seen even in the presence of coronary artery disease. Presently, a new concept called nuclear perfusion study is added to the stress test. This factor has helped to minimize the limitations and improve the diagnostic capability of stress tests.
Cardiologists are physicians who diagnose and treat ailments related to the cardiovascular system that comprises of the heart, arteries, and veins. Pediatric cardiologist is a physician who focuses on diagnosing and treating heart problems in infants, children and young adults. Cardiologists specialize in treatment of angina (chest pain), heart attack, heart failure, high blood pressure and irregular heart beats. A cardiologist has to complete medical school and undergo residency in internal medicine for a period of three years. Further three years of specialization in the field of cardiology is required. For pediatric cardiologists a specialization in pediatrics is required prior to cardiology specialization. Cardiologists are specialists who provide complete heart care; they can determine the working condition of a person's heart by means of different tests. The responsibilities of the cardiologist include:
- The primary function of a cardiologist is to check on how well a person's heart is working.
- They determine this by asking for various tests like the treadmill test (exercise electrocardiogram), and through procedures like angioplasty, cardiac catheterization etc.
- They offer treatments for the diagnosed heart diseases through interventional cardiology like angioplasty, where a mechanical device is used to set right the problem in the heart.
- They use electrophysiology that helps in treating the electrical functioning of the heart.
- They also have the additional responsibility of keeping control over the factors that determine the health of the heart such as blood pressure and cholesterol levels. These levels in the blood of a person are kept under control thus keeping the heart comfortably functioning.
Modern techniques used in the field of cardiology
With the advancement in the field of medicine, cardiologists have the access to the latest technologies like:
Auscultation: A stethoscope is used to identify and detect heart abnormalities and murmur in the heart.
Echocardiography: Ultrasonic waves are used to visualize the heart.
Electrocardiography: EKG instruments are used to monitor the electrical activity of the heart.
Holter monitor: Records the EKG for 24 hours and more non-stop.
Modern blood tests: Determining the levels of HDL, LDL, triglycerides, homocysteine, and C-reactive protein helps in easy identification of heart problems.
Stress testing: Determines the levels of stress and cardiac function of the heart.
Coronary catheterization: Functioning of the heart is determined by inserting a catheter into the heart.