What is 3 Dimensional Cardiovascular Cartography (3D CCG)?
It is a new advanced non-invasive technique for early detection of Coronary Heart Disease. It measures the blood flow to the various regions of the heart. If there is a significant reduction of the blood flow, it is suggestive of the presence of obstruction (blockage) in blood vessel, which is decreasing the blood flow.
It also provides an assessment of the functional status of heart, including how stiff the blood vessels are, the likelihood of clot formation, pumping capacity of the heart, etc.
What technology does Cartography use?
The technology used is Trans- Aortic Signal Wave Modulation (TASWM). A 150 KHz signal is passed through the generating electrodes, which travel along the Aorta, the largest blood vessel in the chest cavity and is modulated by the ejection of blood, breathing activity as well as electrical and mechanical activity. The signal is then picked up by the measuring electrodes and demodulated.
Low bandwidth cardio subsonic is recorded using a special instrument called VAD (Vertical Acceleration Detector). This technology is called Flow Turbulence Accelerometry (FTA). There is a difference in the turbulence characteristics of normal and abnormal vessels. Any obstruction due to blockages disturbs this smooth flow of blood and produces characteristic turbulence. This turbulence is detected by the VAD and provides as to which region of the heart is experiencing reduced blood flow. The technique is similar to how a Seismograph picks up vibrations kilometers inside the earth and lets us know whether an earthquake has occurred.
The data, which is acquired, is processed using powerful and advanced mathematical modeling and simulation tools and high speed computing and then various parameters obtained.
How relevant are the tests for measuring cardiovascular functions and blood flow?
The general emphasis in cardiology today is on the anatomy of coronary artery disease; that is, which coronary arteries are involved, and how much narrowing or obstruction there is. Increasingly it is becoming apparent that the amount of narrowing of the coronary arteries is of only minor importance . Such narrowing does not correlate with the patient’s symptoms , the motion of the muscular walls of the heart, the performance of the heart, the blood flow through the coronary arteries, the patient’s prognosis, and the results of coronary artery bypass surgery.
It is important to know how well the heart is functioning and how much is the blood flow reduction rather than knowing the extent of blockages.
How is the 3D CCG testing done?
The patient’s height, weight and body shape are measured and the information fed into the CCG monitor
The patient is made to lie on the bed and disposable electrodes are placed on various specified locations on the chest wall and connected to four pairs of leads for generating and measuring signals. Four leads for the Electrocardiogram are also placed on the chest wall. The blood pressure cuff is fixed to the patient arm and the basal test started.
The second part of the test involves the administration of a drug called Isosorbide Dinitrate (Sorbitrate) placed below the tongue. This drug causes an increase in blood flow to the heart. The test is then repeated. In some cases the test need to be done in a head-up position.
The whole procedure takes about 15 – 20 minutes.
Is there any protocol to be followed?
The person has to observe fasting for a period of 10- 12 hours before the test. It is important to abstain from tea, coffee or soft drinks during the period of fasting. Medicines for the heart and blood pressure should also be withheld for 8 hours.
It is also advised not to smoke or take alcohol for a period of 24 hours before the test. Morning walk or any strenuous physical exercise should be avoided on the morning of the test. Water or a glass of plain milk can be taken if required.
What are the advantages of Cardiovascular Cartography?
3-D CCG is totally non-invasive. There is no injection, no catherization, no anesthesia, no hospitalization and no radiation. Since it is non invasive there is no pain, no risk and no after effects including no physical or mental strain
It is useful in early detection of Heart disease. Even a small blood flow reduction caused by blockages as low as 20% can be detected. It also assesses the functional status of heart and helps in selecting the correct drug for preventing heart attack and controlling hypertension.
It can be repeated several times unlike invasive methods and hence can be used for assessment. It also serves as a motivating factor to undertake lifestyle and diet changes and thereby prevent heart attacks.
Who can undergo Cardiovascular Cartography?
Any adult can undergo the test as a screening method for early detection of heart disease. It is very useful to diagnose whether chest pain is of cardiac or non- cardiac origin, since it provides the valuable Demand: Supply Ratio. Increased D:S is suggestive of Ischemia (Heart related Pain)
It is particularly useful for all high-risk persons like those
- Individuals having Diabetes
- People with high cholesterol/ triglyceride levels
- Those who have high blood pressure
- People who smoke regularly/ take tobacco
- Those who consume alcohol regularly
- Overweight persons
- Persons with relatives having heart disease
- People with minimal physical activity or sedentary lifestyle
- People with stressful lifestyle
3D CCG is also useful for Heart patients
- To determine the extent of heart disease (previous heart attacks)
- To monitor effectiveness of their treatment
- Follow up after angioplasty (PTCA) to detect recurrence.
- Follow up after by-pass surgery (CABG)
How does a 3D CCG help in detection of Coronary Artery Disease?
The invasive procedures and other imaging devices detect the extent and location of blockages in major vessels, whereas, the 3DCCG measures the blood flow of the heart muscle and provides information on how much blood flow is being reduced by the blockages. The major cause of Blood flow reduction is Coronary Artery Disease. It is the blood flow reduction, which isthe cause of the patient’s symptoms and not the anatomical presence of blockages.
What are the other information obtained from 3D CCG?
Cardiovascular Cartography provides information on the functional status of the heart. It tells you what is the amount of blood pumped by the heart in one minute (Cardiac output), how much resistance is there against which it has to pump (Systemic resistance), how much volume it is pumping during every beat (Stroke volume), what proportion of blood is pumped (Ejection fraction) etc. All these parameters are extremely useful in assessing how well the heart is functioning. It also helps the physician to choose the right drug for his high blood pressure (hypertension) or other heart problem.
It also provides information on whether a person has Atherosclerosis (hardening of the arteries due to cholesterol deposits), whether he has a tendency to have erratic beats (arrhythmogenicity) and whether he has increased chance of forming clots (thrombogenicity), how much is the burden on the heart etc.
In short it can be called as “Heart Function Test” just like Liver function test and Lung function tests
How does the patient obtain the results of the Cardiovascular Cartography?
Cardiovascular Cartography measurement report is generated by the 3DCCG machine automatically after the test is completed and hence there is no scope of subjectivity. A doctor specially trained in Cardiovascular Cartography interprets the findings and makes a Summary Report. The practitioner then reviews the report of the Cardiovascular Cartography with the patient and correlates it to their particular symptoms or condition.
The report is user-friendly and easy to understand by anyone with some knowledge on cardiovascular physiology and functional medicine. Cardiovascular physiology and functional medicine is taught in the medical schools, however these important functional parameters were not available non-invasively earlier, thus its application was limited all these years. Imagine if we had to drill a hole on the hand and insert a probe deep inside to measure the body temperature, nobody would have used temperature as a parameter to establish fever. Because it is easy to measure body temperature, it is used as an important functional parameter.
How accurate is 3D CCG in detecting Coronary Artery Disease?
Studies show that CCG has a higher sensitivity and specificity when compared to other non invasive test like Electron Beam CT, PET scan, Stress Thallium, Stress ECHO and TMT. The sensitivity of CCG is 91% and the specificity is 92% in correlation with angiography, while the TMT has a mean sensitivity of 65% and a specificity of 77%.
I recently had a stress test that was perfectly normal but3-D CCG showed that I have reduced blood flow to the Heart. Does that mean that this test or the stress test was wrong?
No. Although both tests were looking for heart disease, they are doing it in different ways. Your normal stress test indicates that the plaque build up has not yet reached the point where the blood supply reduction is causing abnormal electrical activity, which can be picked up by ECG. Your cardiovascular cartography measures the actual reduction in the blood flow and tells us that the process has indeed begun, and there is an opportunity to modify all controllable risk factors to minimize the chance of having a major heart related event.
I have no major risk factors for heart disease, I exercise regularly and I am very careful about my diet. Should I undergo this test?
It is important to continue to follow a “heart-healthy” lifestyle and it is likely that your heart has benefited from your modified lifestyle. However, there are a few factors that we can never control, for example our age, sex and genetic predisposition (family history). For some individuals, reduced blood flow to the heart muscle may be the only indication that they may be at higher than expected risk for a heart attack. Hence all it is advisable for all adults to undergo this test.
What are the limitations of a Cardiovascular Cartogram?
3- D CCG does not measure the actual anatomical location or extent of blocks. Hence for a person who is contemplating surgical intervention like Angioplasty and By-pass surgery, it would be useful only to the extent of functional assessment of the heart and circulatory system, which may be useful in prognosis of the surgery, but not for planning the actual surgery or angioplasty.
Why is 3-D CCG not widely known?
The technology is relatively new, just about 3 to 4 years old, when compared to other techniques like angiography, which has been there since 40 years. Most doctors are not aware since it was not taught to them during their study program. However all the functional parameters provided by 3DCCG and their significance is being taught in the medical colleges.
My doctor has never told me about this procedure…why is it so?
Cardiovascular Cartography is a relatively new, highly specialized and sophisticated technology. There are now hundreds of published papers on importance of blood flow measurement. 3D-CCG meets all necessary international certifications, and is in use in over 15 countries worldwide. However, most of this information is in sources read primarily by few doctors. Please keep in mind that it is quite likely that your physician does not yet know about this technology or the implications of the test.
Can you tell me how much blockage there is in my coronary arteries?
Although it is possible for us to make some conclusions about the degree of coronary narrowing that is likely to exist based on the amount of blood flow reduction, it is not a primary purpose of this test. The primary purpose of the test is to detect disease before there is much narrowing. Doctors now know that more than half of all heart attacks occur at sites of less than 50% narrowing. No other noninvasive test in cardiology can detect this type of early disease.
I had a 3DCCG test that showed that there was reduced blood flow to my heart muscles, I did an angiogram and found that I had normal blood vessels. But I still have chest discomfort. Was the 3DCCG wrong?
No, neither Angiography nor the 3DCCG was wrong, angiography has just proved that the reason for your blood flow reduction, and thus your symptoms, is not due to the blockages in your main blood vessels of the heart. There are 10 main causes for the reduction of blood flow to the heart, blockages being one of them. Discuss with your doctor 3DCCG report can reveal what could be the other reason for your symptoms and the reduced blood flow.
I had a 3DCCG test done which showed that I have normal blood flow to my heart, I went through an angiography procedure and found I have 100% block in one vessel and 80% in the other. Was the Angiography right?
Yes, both Angiography and 3DCCG are correct. Angiography measured the blockages that showed 100%. Well! Patients having such high-grade disease normally would have already developed excellent collateral circulation. If it were not for the “natural bypass” of that vessel, the 100% blockage would have caused a heart attack in that region of the heart. These tiny vessels are less than 0.5 mm and hence cannot be seen in an angiogram. 3DCCG measures this blood flow irrespective of the size of the blood vessel.