Echocardiography is the use of ultrasound to assess the structure and function of the heart. This can be performed by placing an instrument that sends ultrasound waves through a transducer over the left side of the chest. Similarly, the ultrasound can be sent from a small transducer at the end of a scope similar to endoscope from the food pipe to examine the heart known as transesophageal echocardiography or TEE.
Echocardiography images the heart in real time. The details of the various structures, the contraction and relaxation of the heart muscle, opening and closing of the valves and the integrity of the outer sac that lubricates the heart can be seen. Blood, as it moves through the heart from one chamber to the other and out to the heart can be imaged like the satellite weather video or still picture. This is known as Doppler echocardiography and color flow imaging. Based on these various parameters, the presence or absence of various types of heart disease can be diagnosed.
Echocardiography is an important tool that is used in various different roles in the outpatient, inpatient, emergency room, operating theaters and in the critical care settings.
It is used in diagnosing whether there is a problem with the heart or not?
Heart disease is very variable from defects in the heart structure present at birth, to a heart attack resulting from sudden blocking of the channel (artery) taking oxygenated blood to the heart muscle. There are also several other diseases not related to heart that can affect the heart if they are not well-taken care such as high blood pressure, diabetes, obesity and lung disease.
Does it help sort out whether the patients’ symptom is from heart ailment or not?
Patients with heart disease will present with varying complaints: breathlessness, excessive tiredness doing daily activities, light headedness, palpitations, chest pain, and sudden collapse. Although some of these complaints are specific for certain heart ailments such as severe chest pain and breathlessness indicates a heart attack, the majority of the symptoms lack the specificity to identify the type of heart ailment causing the symptom. For instance, a symptom such as breathlessness may be from the disease of the lung as well as from the heart or from anemia. Real-time echocardiography will be able to assess whether the symptom is due to heart ailment or not.
Echocardiography identifies the nature and severity of the heart problem:
Most of the symptoms if they are from the heart, result from the following:
- Inability of the heart muscle to pump the blood. The heart muscle is weak from a heart attack or from viral infection or from uncontrolled high blood pressure for a long time or from diseases of the heart muscle such as cardiomyopathy.
- Inability of the heart muscle to relax and accommodate the blood. The muscle is thick due to disease of the heart muscle such as hypertrophic cardiomyopathy or due to obstruction of the aortic valve such as aortic stenosis or due to long-standing uncontrolled blood pressure.
- Valves not opening or closing properly leading to obstruction – stenosis or leaking – regurgitation of the blood into the left ventricle or right ventricle. In some patients with elevated blood pressure or elevated cholesterol, the aortic valve can become stiff from calcification and the opening will gradually decrease. This will give rise to difficulty in breathing or feeling tired or light headed even before it becomes critically small. Echocardiography can identify and quantify the obstruction to help the physician to make treatment decisions.
- Mixing of the blood within the heart due to birth defects such as holes between heart chambers. Unfortunately, getting health care is not uniform and standardized in India; as a result, children born with birth defects are not diagnosed when they are not even born, or at least early in life soon after birth to be treated effectively. However, in those where the births are occurring in the established maternal centers echocardiography is used to diagnose heart defects and to make treatment decisions.
Thereby one can diagnose whether the patient’s symptom is from the heart or not. If it is from the heart we can determine whether it is due to muscle problem or valve-related problem. Similarly, if the patient is having chest pain we can assess whether it is from a heart attack or from other causes.
Echocardiography is used to monitor the effectiveness of treatment for those with heart disease:
Heart disease treatment can be monitored using echo parameters. For instance, in patients with heart failure where the heart is enlarged and does not empty the blood fully or it is leaking back across one of the valves and the pressures in the heart chambers are increased, echocardiography can be used to assess the same parameters after instituting therapy either immediately or after some time.
Echocardiography is used to guide and monitor valve interventions in the catheterization laboratory:
Echocardiography is also used in the catheterization laboratory to guide the interventional cardiologist to perform valve related procedures such as percutaneous aortic valve replacement or mitral valve clip repair safely and to assess the results of the procedure.
Echocardiography is used in the operating theaters to guide and monitor valve repairs by cardiac surgeons:
Since the chest is going to be opened for surgery, real-time images of the heart and blood flow are imaged from the food pipe using TEE. This allows the cardiologist, cardiac anesthesiologist and the cardiac surgeon to assess the integrity of the valve before and after repair, assess the adequacy of the repair and if there is an issue that can be corrected then and there.
Over the past 40 years, echocardiography has emerged as an invaluable tool in the management of patients with heart disease. This technology is well developed in western countries, and the cardiologists are specialized in this field like interventions. However, in India, although large numbers of echocardiographic procedures are done, there is quite a paucity of cardiologists specialized in the art of echocardiography and the quality is very variable.