Observing a person while walking on a treadmill allows us to determine a person’s level of fitness, and to evaluate the cause of chest pain that could suggest cardiac ischemia. A technician, physician assistant, or physician are present at all times, and we are prepared for any problems that might arise. Exercise is performed in 3-minute phases until the person reaches a target heart rate, or until other end points are reached. Treadmill stress testing has been used for decades, unfortunately the procedure is only about 65% accurate in identifying people with chest pain due to coronary artery disease. The procedure is safe and commonplace, but has been supplanted by more accurate studies, as noted below.
SPECT myocardial perfusion imaging
People with arthritis, back pain, abnormal electrocardiograms, and other pre-existing heart or circulatory problems often cannot walk on a treadmill or reach the target heart rate. In these circumstances, we can evaluate people for suspected coronary artery disease by performing a nuclear imaging study of the heart before and after a person has been given medications such as adenosine or regadenoson, both of which dilate the coronary arteries for a few minutes. The medicines often are infused while the person is walking at a slow pace on the treadmill.
We combine the “chemical stress test” with a low dose of radioactive isotope, either Tc99m or Thallium 201, which are detected by a nuclear camera and gives us a three-dimensional image of the blood supply to the heart muscle. The technique is somewhat analogous to CT scanning, and is called “single photon emission computed tomography” or SPECT imaging for short.
Combining information from the electrocardiogram, chemical stress test, and images obtained from SPECT imaging, we can increase the accuracy of stress testing to 90 % or better to detect significant coronary artery disease.
Our nuclear program is accredited by ICANL, the Intersociety Commission for Accredited Nuclear Laboratories.
PET myocardial perfusion imaging
Even though SPECT cardiac imaging is vastly better than conventional stress testing to detect coronary artery disease, the technique has some limitations and drawbacks. First is the amount of time to do the study, which can take from 2 to 3 hours. Second is the problem of artifact caused by soft tissue, which can make images difficult to interpret, especially in very obese individuals, or in women with large breasts or men with large abdomens.
The solution is to use a different type of nuclear camera, and a different type of isotope. This technique is called “positron emission tomography” or PET scanning for short. Adenosine or regadenoson are infused at the same time as the radioactive isotope is infused, and the test from beginning to end takes only 30 minutes while the individual is lying still on a bed as images are obtained. The isotope is Rubidium-82, which has a half life of only a few seconds, so there is no effect of radiation lingering in your body.
Riverside Cardiology Associates is proud to be the first and only cardiology group in our area to offer this service, and we can accommodate people in both the main office in Riverside and our other office in Temecula.
Echocardiography is a risk-free technique to take pictures of the heart, including the valves, major veins, aorta, and chambers. Very high frequency ultrasound is directed into the chest from different angles, and the reflected sound waves are analyzed to create a two-dimensional image of the heart. We can also see blood flowing through the chambers. Subtle abnormalities not evident by physical examination or chest x-ray are easily detected by this technique. Echocardiography is very useful for analyzing heart murmurs and checking cardiac pump function. The procedure takes approximately 15 to 20 minutes to perform, and images can be stored on a compact disc.
Our echo program has been accreditied by ICAEL.
Other ultrasound procedures (carotid ultrasound, abdominal ultrasound)
Going one step further, we can use the ultrasound machine to take images of the carotid arteries, abdominal aorta, and other vessels in the body. This technique is an accurate screening tool for carotid artery disease and abdominal aneurysms.
Holter monitor and long term arrhythmia surveillance techniques
Many people have irregular heart rhythms, which can be intermittent in nature. An electrocardiogram only captures 12 seconds of information. We employ several different techniques in order to detect and characterize arrhythmias. The most common technique is a Holter monitor, which is a recording device attached by electrodes to your chest to capture every heart beat for 12 to 24 hours. The recording is then analyzed by computer, and representative strips are printed out.
Another technique is an “event recorder,” which requires the individual to push a button in order to capture the event. Nothing is recorded otherwise. A third technique is a Cardionet recorder, which the individual can wear for 2 weeks or longer, and take off for showering, etc. The device transmits your heart rhythm via cell phone to a central monitoring station on the East coast, and results are called or faxed to us immediately.
As a last option, we can implant a very small device under the skin of the chest. This device, called a “Reveal” event recorder, is useful for sporadic arrhythmias which are hard to capture by any of the other techniques.
Advanced lipid testing and treatment (Berkeley Heart Labs, VAP, NMR)
Lipid abnormalities, including high levels of cholesterol and triglycerides, are a major risk factor in arteriosclerosis and coronary artery disease. However, it is no longer sufficient to measure just total cholesterol levels, triglycerides, LDL (“bad cholesterol”), and HDL (“good cholesterol”). Over 40 per cent of patients with proven coronary artery disease have “normal” cholesterol levels. We emphasize an aggressive approach to lipid testing, and utilize advanced lipid tests ordered through three specialty laboratories in order to have a better understanding and treatment plan for a patient’s lipid abnormalities. Often we use combination therapy with multiple medications to reduce a patient’s “residual risk” for another heart attack. Advanced lipid testing helps us to tailor a medical regimen to achieve this goal.
EECP (Enhanced External Counter Pulsation)
Traditional treatment for patients with symptomatic coronary artery disease and angina has included coronary bypass surgery, nonsurgical procedures such as coronary artery stenting, and multiple medications. Despite this armamentarium, there are still patients who have angina refractory to usual treatment. In these instances, we offer EECP, which is a treatment plan originally developed in China.
The technique involves placing large inflatable cuffs on the lower legs, thighs, and lower abdomen. The cuffs are sequentially inflated between each heart beat, basically in a syncopated rhythm, in order to push blood out of the lower extremities and back into the aorta. This occurs between each heart beat, and causes more blood to flow through the coronary arteries while the heart is relaxed. When the cuffs deflate, the heart has less work to do to pump blood into the aorta.
The end result is that the coronary arteries dilate, the heart is allowed to pump with less effort, and patients report improvement in symptoms and well being. The treatment requires a commitment of one hour per day, 5 days per week, for a total of 7 weeks. The procedure is reimbursable by Medicare.
Clinical research trials
We formed a separate business, Inland Clinical Research, in 2000, and have participated in many clinical research trials involving investigational drugs that ultimately came to market. We have worked in trials involving patients with diabetes mellitus, coronary artery disease, hypertension, cholesterol abnormalities, atrial fibrillation, and congestive heart failure. These trials have allowed us to stay on the forefront of newer drugs and information, and has improved patient care. Our certified clinical research coordinator is Tina Mercado, who works closely with patients, sponsors, and monitoring personnel. Inland Clinical Research has now been folded into Riverside Cardiology Associates.
Pacemaker and AICD monitoring/programming
We care for patients with pacemakers and implanted cardioverter/defibrillators (AICD’s). We have testing and programming equipment in our main office for most of the major manufacturers, including Guidant, St. Jude Medical, and Medtronic. We also have close working relationships with manufacturers’ representatives and nearby pacemaker specialists.
Tilt table testing
Some individuals who have repeated episodes of fainting and lightheadedness have a condition called orthostatic hypotension, which is basically a condition in which the blood pressure suddenly and precipitously drops and causes a person to pass out. We perform tilt table testing to evaluate this condition. The patient is secured to a table, blood pressure, heart rhythm, and vital signs are recorded minute by minute, then the patient is tilted upright while still attached to the table. Sometimes a medication is infused to recreate the condition. An abnormal tilt table test helps us to explain often confusing symptoms and to tailor a medical program to prevent episodes from recurring.
Consultation and acute coronary care
Our cardiologists first and foremost are clinicians, and all are board certified both in internal medicine and cardiology. We perform consultations at the request of other doctors, and act as patient advocates to assure prompt and excellent patient care.
We care for both the acutely ill and chronically ill patient with cardiovascular disease. Dr. Ho is part of the rapid response team for acute STEMI at the HeartCare Center at Riverside Community Hospital. Our physicians also cross-cover the cardiology group at Riverside Medical Clinic.
We are available nights and weekends to answer your calls and to assist you.
Diagnostic cardiac catheterization
Cardiac catheterization and coronary angiography are considered the gold standard for diagnosing heart disease, including coronary narrowings, valvular disease, and cardiomyopathy. Diagnostic cardiac catheterization provides the roadmap for further treatment, whether bypass surgery, valve surgery, stenting, or continued medical management. On occasion we also perform intravascular ultrasound of the coronary arteries when regular xray images are inconclusive. We perform these procedures at Riverside Community Hospital and Loma Linda University Medical Center.
Coronary interventions (angioplasty, stents, thrombectomy, atherectomy)
For patients who present with critical narrowings or acute obstruction of the coronary arteries, we employ an arsenal of techniques to open the artery and restore blood flow. When a patient is experiencing angina pectoris, coronary intervention is an alternative to coronary bypass surgery. In an acute heart attack, opening the infarct-related artery and restoring blood flow to ischemic muscle prevents further damage, and helps to restore cardiac function. Techniques involve insertion of a very fine wire through the narrowed or blocked artery, then deployment of a balloon and stent to open the artery completely. Sometimes it is necessary to extract clots with specially designed equipment, and to infuse medications and clot-dissolving drugs directly into the affected artery. Coronary interventions have revolutionized care of the patient with an acute heart attack and dramatically reduced time spent in the hospital to recuperate.
The same techniques used to open occluded or narrowed coronary arteries can be employed for patients with narrowed carotid arteries. The carotid arteries are the major conduits for blood to reach the brain, and disease in the carotids can lead to stroke or transient ischemic attack (TIA). Utilizing specially designed guidewires with a basket at the end to collect debris, a self-expanding stent can be placed safely into the internal carotid artery in a matter of minutes. The long term prognosis for prevention of stroke or TIA is just as good with stenting as it is for carotid surgery. Dr. Ho is trained and experienced in these techniques.
Peripheral angiography and interventions
Atherosclerosis also affects the aorta, renal arteries, and the major arteries to the legs. Obstruction or narrowing of the arteries to the legs causes claudication, or pain in the legs or buttocks when walking. The same stenting techniques used for coronary disease can be adapted for use in leg ischemia and renal artery stenosis.
Pacemaker implantation, arrhythmia management
We care for patients who have excessively slow heart beats due to disease in their electrical conducting system. Pacemaker implantation involves local anesthesia then creation of a subcutaneous pocket beneath the collarbone, into which the pacemaker is placed. We then insert one or two insulated and extremely flexible electrode wires into the cardiac chambers. The other ends are attached to the pacemaker. When the heart beats, the electrodes send signals back to the pacemaker, which stands by. However the pacemaker is programmed to stimulate the heart by way of the electrodes if there is any hesitation in the heart rhythm. The procedure takes approximately one hour to perform, and often patients go home the same day.
In some instances, ultrasound images of the heart are not technically satisfactory, for instance when a person has chronic lung disease or a barrel-shaped chest. In these circumstances, we often perform transesophageal echocardiography.
The patient is given medications to anesthetize the throat, and then put to sleep with a sedative that causes amnesia. A specially designed ultrasound probe is then passed carefully into the esophagus, and we obtain images of the heart from behind, basically looking at the heart from the inside out. Image quality is spectacular, and the level of detail is unmatched by other techniques. The procedure takes 10 to 15 minutes, and the patient awakens with no recollection of the study.
The cardiac rehabilitation program at Riverside Community Hospital is adjacent to our main office, and Dr. Pond serves as the medical director. He is available for consultation and guidance of the center’s team of nurses and therapists. Dr. Pond originally owned and operated a free-standing cardiac rehabilitation program in Riverside before any local hospitals had their own program, and merged with Riverside Community Hospital in 1988.
The rehab program emphasizes supervised aerobic exercise, nutrition, and life style changes as the key steps to recovery from a heart attack or heart surgery. The program is approved by Medicare and all major health insurance plans.