Common Diagnostics and Advanced Cardiovascular Technology
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Each condition is different, but your physician and cardiovascular medical team may use a variety of tests and treatments. Common diagnostic tests are listed below, along with a short description. Or you can skip ahead to learn more about our advanced treatments.
Angiography (Coronary Arteriography)
Coronary angiography is an X-ray examination of the blood vessels or chambers of the heart, used to diagnose blockages and other problems in arteries and veins. DMC Cardiovascular specialists insert a very small tube (catheter) into a blood vessel in your upper thigh (groin area) or arm. The tip of the tube is positioned either in the heart or at the beginning of the arteries supplying the heart, and a special fluid (called a contrast medium or dye) is injected. This fluid is visible by X-ray, and the pictures that are obtained are called angiograms.
Ankle-Brachial Index (ABI)
The ankle-brachial index uses blood pressure cuffs to provide a specific and sensitive test for diagnosing peripheral artery disease (PAD). ABI measures your systolic blood pressure at your ankle and divides it by the systolic blood pressure at your arm. It is recommended that every smoker or diabetic over 50 years of age, and all patients over 70 years of age have their ABI monitored.
Blood and Urine Tests
These are used to test levels of proteins and other specific things that should, or shouldn’t, be in your body.
Cardiac Catheterization (cath)
An invasive test that introduces a small catheter into the heart from the groin or arm, this allows measurement of various pressures inside the heart to aid in the diagnosis of heart failure. Biopsies of the heart tissue may be obtained in order to determine underlying causes of heart failure.
Coronary Calcification Scan
A coronary calcification scan uses computed tomography (CT) technology to take multiple, clear pictures of the heart and calcium deposits in the coronary arteries. By measuring the calcium deposits in the coronary arteries, the physician gets a good idea of how much plaque has built up and "hardened" in the arteries. This calcification measurement is an excellent indicator of the patient's risk of a heart attack and other heart problems. A negative (or low calcium) score generally indicates a low risk for future coronary artery blockages and coronary events. The test is painless and takes about 10 minutes.
The 64-slice CT provides clear, non-invasive, 3D images of the coronary arteries with remarkable detail and speed. This sophisticated examination can discover signs of heart disease that may be invisible to stress testing and EKG and calcium scoring alone. Taking minutes to perform, Coronary CTA can provide important diagnostic information about the structure and function of the heart, such as the presence of calcium and/or fatty deposits (plaque) in coronary arteries.
A diagnostic test which uses invisible X-ray beams to produce images of internal tissues, bones, and organs onto film.
An echocardiogram, also known as an "echo", is an ultrasound of the heart. The test is non-invasive, painless and safe. High-frequency sound waves bounce off the structures of the heart and create a computerized, moving picture of the beating heart. Highly trained cardiac imaging specialists at CVI use these images to detect heart damage and disease.
An echocardiogram is especially useful for detecting congenital heart disease and problems with the heart valves. The test is sometimes used in combination with a stress test to identify changes in the function of the heart muscle when exercise is performed. Some problems with the heart are easily missed when the heart is at rest and only become apparent under the stress of exercise.
Electrocardiogram (ECG or EKG)
An electrocardiogram (ECG) records the electrical activity of the patient’s heart. During the test, ten electrodes are attached to the patient’s legs, arms and chest. The electrodes create a record of the heart’s rhythm, including any arrhythmias that occur during the test. Sometimes an ECG is performed while the patient exercises on a treadmill. This is called a Stress Test, which is designed to record electrical activity of the heart during physical exertion.
Electrophysiology (EP) Study
Electrophysiology allows a cardiologist to accurately diagnose the precise cause of an arrhythmia and select the best possible treatment. During an EP study, a specially trained cardiologist may provoke arrhythmia events.
As a result, EP studies can
- Diagnose the source of arrhythmia symptoms
- Evaluate the effectiveness of certain medications
- Predict the risk of a future cardiac event, such as Sudden Cardiac Death
- Assess the need for an implantable device (a pacemaker) or treatment procedure (radio frequency catheter ablation)
An EP study is performed with the patient under local anesthesia and conscious sedation (twilight sleep). A narrow, flexible tube called a catheter is inserted into a blood vessel and the heart. Once the catheter reaches the heart, electrodes at its tip gather data.
Microvolt T-Wave Alternans Test
The Microvolt T-Wave Alternans Test is a non-invasive test used to identify patients at risk of life threatening heart rhythm disturbances. Similar to a Stress Test, electrodes and sensors are applied and the patient is asked to exercise on a treadmill for the duration of the test. The Microvolt T-Wave Alternans test permits measurement of the heart’s T-waves at a microvolt level.
Monitoring devices are used to detect irregular heart rhythms over varying periods of time.
- Event Recorder - An event recorder is a pager-sized box that can create a 1 to 2 minute recording of the heart rhythm. When you experience symptoms, you press a button to record the heart rhythm.
- Holter Monitoring - Holter monitoring devices are portable ECG recorders that you wear during normal activity for 24 to 48 hours. During this time, the device makes a detailed record of the heart’s activity.
- Insertable Loop Recorder (ILR) - For occasional arrhythmias, an insertable loop recorder may be implanted under you skin 12 to 18 months. The device creates a long-term record of your heart’s rhythm.
MRI (magnetic resonance imaging) uses radio waves and a magnetic field to provide clear and detailed pictures of the heart and blood vessels. A non-invasive tool, MRI is becoming very important in the diagnosis and management of heart failure.
Positron Emission Tomography Scans (PET)
PET scans are non-invasive, providing detailed information about the blood supply and metabolic activity of the heart. By revealing cardiac metabolism rates and other information, PET studies help physicians identify the best therapies for patients. They are particularly helpful in treating high-risk patients with coronary disease and heart failure. These studies can not only show heart muscle with inadequate blood flow due to blockages, PET studies can also identify heart muscle that has been damaged from past heart attacks.
Taking it a step further, PET studies can even distinguish between irreversibly damaged heart muscle and damaged heart muscle that has the potential to recover after bypass surgery or stent placement.
Another advantage: PET studies can be completed in about 45 minutes while a traditional nuclear cardiac imaging study takes from 4 to 5 hours. Plus, PET studies provide greater scan clarity than traditional nuclear studies. This clarity provides more accurate interpretation
Stress tests are a noninvasive technique commonly used to evaluate the flow of blood to your heart muscle. They can identify areas of the heart muscle that have an inadequate blood supply as well as the areas of heart muscle that are scarred from a previous heart attack.
The tests also can evaluate the pumping function of the heart. Some patients may need an additional level of testing using an imaging agent. These tests are often called nuclear cardiology tests.
Nuclear medicine tests help identify patients at increased risk for a heart attack and those who may be candidates for procedures such as coronary angiography, angioplasty and heart surgery. While tests are usually done while the patient is exercising on a treadmill or stationery bike, some patients who can’t exercise may be given a "chemical" stress test using a drug that simulates exercise.
Before the test, the patient is connected to equipment which will monitor the heart. The patient then walks slowly on a motorized treadmill. The speed is slowly increased and the treadmill is tilted to produce the effect of going uphill. Patients can stop the test at any time if needed. Medical professionals are present throughout the test.
At DMC, several types of stress tests and nuclear cardiology tests are performed:
- Exercise Stress Test (GXT): The patient is monitored by EKG and blood pressures are taken before, during and after the test. The test is symptom limited. Average time on the treadmill is six to 12 minutes. The entire test takes 30 minutes.
- Exercise Stress Echocardiogram: Before and after the treadmill test, echocardiogram pictures are taken. This compares the wall motion of the heart at rest and when it becomes stressed. Average time on the treadmill is six to 12 minutes. The entire test takes 45 minutes.
- Dobutamine Stress Echocardiogram: During the treadmill test, the patient is given the medication Dobutamine intravenously. The medication slowly increases the heart rate and contractility until the desired heart rate is obtained or the patient’s symptoms limit the study. Echocardiograms are taken before, during and after the Dobutamine infusion. The test takes approximately one hour.
- Exercise Sestamibi (Stress Cardiolite): Prior to exercise, a Cardiolite injection is given and resting images taken of the cardiac structure. When a predetermined heart rate has been achieved during the stress test, a second injection of Cardiolite is given. After a rest period, a set of images of the heart is taken. The entire test lasts approximately three hours.
- Persantine Sestamibi (Persantine Cardiolite): Prior to exercise, a Cardiolite injection is given and resting images taken of the cardiac structure. The patient also receives Persantine intravenously, then a second injection of Cardiolite. After a rest period, a set of images of the heart is taken. The entire test lasts approximately three hours.
- Dobutamine Sestamibi (Dobutamine Cardiolite): Prior to exercise, a Cardiolite injection is given and resting images taken of the cardiac structure. During the treadmill test, the patient is given the medication Dobutamine intravenously. The medication will slowly increase the heart rate and contractility until the desired heart rate is obtained or the patient’s symptoms limit the study. A second injection of Cardiolite is administered. Echocardiograms are taken before, during and after the test. The test takes approximately three and a half hours.
Tilt Table Test
The tilt table test is used to evaluate the causes of fainting. The test checks how changes in body position can affect blood pressure. The patient lies on a special table and heart rhythm and blood pressure are monitored as the table tilts the patient to a 70- to 80-degree angle.
Advanced Cardiovascular Technology and Treatments
Expert cardiovascular and thoracic surgeons perform a full range of major surgeries, including open-heart surgery, aortic surgery, aneurysm repair surgery and cardiovascular surgery. After surgery, care is provided in our nationally-recognized intensive care units in an area dedicated to cardiac patients.
3D Cardiac Mapping
Electrophysiology experts at the DMC Cardiovascular Institute helped develop a 3-D cardiac mapping system that enables physicians to locate the precise location of arrhythmias. This imaging technology is “like a Global Positioning System for the heart.”
DMC Cardiovascular experts offer multiple procedures to repair congential and other defects to the aorta. Available are open thoracic and abdominal aneurysm repair, aortic surgery for occlusive disease and minimally invasive aortic surgery. Specific surgical procedures include aortofemoral bypass, mesenteric bypass, renal bypass, thoracic endovascular aneurysm repair (TEVAR), abdominal endovascular aneurysm repair (EVAR), iliac artery stenting, mesenteric artery stenting and renal artery stenting. Complex aortic reconstructions are also offered by our specialists, including aortic dissection and debranching procedures in preparation for minimally invasive aneurysm repair with a stent.
A treatment used to remove the plaque that is blocking the artery.
An atherectomy is a procedure in which a catheter with a sharp blade on the end removes plaque from a blood vessel. The catheter is inserted into the artery through a small puncture in the artery, and it is performed under local anesthesia. The catheter is designed to collect the removed plaque in a chamber in the tip, which allows removal of the plaque as the device is removed from the artery. The process can be repeated at the time the treatment is performed to remove a significant amount of disease from the artery and eliminating a blockage.
There are three main types of atherectomy, each using a specific type of catheter tip.
- Rotational Atherectomy
Sometimes called “rotoblator”, rotational atherectomy is a common procedure. It uses a catheter tipped with a diamond burr that is guided to the blockage. While the burr spins at a very high speed, it grinds the hardened plaque into minute particles that can be safely eliminated by the body.
- Directional Atherectomy
Directional Atherectomy is designed to remove buildup of softer plaque. After catheter insertion, a balloon is inflated along the catheter that pushes the blade toward the plaque. The blade cuts away at the plaque and stores it in a special chamber. The balloon is then deflated and the plaque is removed with the chamber as the catheter is withdrawn.
- Transluminal Extraction
Transluminal Extraction is a device that uses spinning blades to cut away plaque and a vacuum device to suction the plaque out of the blood vessel through the catheter.
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, usually due to narrowing of the vessel due to atherosclerosis. Sometimes called percutaneous transluminal coronary angioplasty (PTCA), balloon angioplasty is a minimally invasive procedure that opens blocked or narrowed blood vessels.
Using a guide wire called a balloon catheter, physicians insert a very small, empty and collapsed balloon into the narrow portion of the target blood vessel and momentarily inflate it to a fixed size. The balloon crushes the fatty deposits, opening up the blood vessel to improved flow before the balloon is collapsed and removed. Balloon angioplasty can be used to unblock clogged arteries in the legs, arms, kidneys, brain and other parts of the body. Angioplasty has come to include all manner of vascular interventions typically performed in a minimally invasive (percutaneous) method.
A balloon valvuloplasty is a minimally invasive procedure in which a patient’s narrowed heart valve is stretched open to allow improved function and blood flow without open heart surgery. Using a catheter, physicians insert a small deflated balloon into the blood vessel that is threaded up to the opening of the narrowed heart valve. The balloon is inflated, which stretches the valve open.
Bi-Ventricular Pacing Devices
Our experts are internationally known for their extensive work with bi-ventricular pacing devices. By stimulating the left and right ventricles simultaneously, the bi-ventricular pacing system resynchronizes the heart and dramatically improves the heart’s ability to pump blood.
Bypass surgery creates a detour around the narrowed or blocked sections of the artery. To create this bypass, a cardiovascular surgeon connects a vein or a tube made from man-made materials above and below the area that is blocked. This creates a new path for blood to flow.
In a cardiac ablation procedure, a catheter is used to guide tiny electrodes into the heart. When the damaged tissue is identified, a burst of radiofrequency energy destroys the tissue that is causing the abnormal electrical signals. With the damaged tissue destroyed, the heart usually returns to a normal rhythm.
Our expert physicians often perform cardioversion, either with drugs or an electrical impulse, to “reset” the heart to its normal rhythm (sinus rhythm).
Cardioversion may successfully restore regular heart rhythm in more than 95 percent of patients, but it’s not always effective as a long-term solution. More than half of patients eventually go back into atrial fibrillation. In these instances, anti-arrhythmic medications may be needed indefinitely.
Carotid Artery Stenting
Physicians from DMC Cardiovascular services train other doctors nationwide in this minimally invasive treatment that prevents stroke in patients with carotid artery disease. Carotid artery stenting with embolic protection system gives new hope to high-risk patients who might not otherwise be candidates for traditional surgery.
The key to this procedure is a tiny blood filter (embolic protection system) that collects plaque that might dislodge from the artery wall and cause a stroke. As a result, this minimally invasive procedure is safer for high-risk patients than the traditional surgery. In time, minimally invasive procedures like this may prevent up to half the strokes that occur today.
Catheter Radiofrequency Ablation
Atrial fibrillations can be caused by a small section of abnormal tissue in the heart, which can be destroyed with catheter radiofrequency ablation. In this procedure, a catheter (a thin, flexible tube) is used to guide tiny electrodes into the heart. When the damaged tissue is located inside the heart, a burst of radiofrequency energy destroys the tissue that is causing the abnormal electrical signals. With the damaged tissue destroyed, the heart usually returns to a normal rhythm.
DMC Cardiovascular physicians use two types of ablation to treat atrial fibrillation:
- Pulmonary vein isolation ablation (PVI ablation or PVA)
Electrically isolating "hot spots" in the pulmonary veins that trigger atrial fibrillations and destroying them. PVI eliminates atrial fibrillation in 60 to 80 percent of patients who are treated. Medications that did not help patients prior to ablation are often effective.
- AV node ablation with pacemaker
In this procedure, radiofrequency energy is applied through a catheter to destroy a small area of tissue near the atrioventricular (AV) node. For most patients, this procedure completely blocks the heart's electrical impulses and eliminates atrial fibrillation. As a result, doctors must implant a pacemaker to establish a normal rhythm. Anticoagulation medication may also be required to reduce the chance of developing blood clots.
Endovascular Stent Grafting
Endovascular stent graft repair is designed to help prevent an aneurysm from bursting. The term endovascular means inside blood vessels, and surgeons use specialized instruments that require only small incisions or punctures in an artery or vein. Through these punctures, a cardiovascular surgeon inserts long thin tubes, called catheters, which carry the devices through the blood vessels to the location of the aneurysm. They can then be placed to re-align and strengthen arteries.
An endovascular stent graft is a tube composed of fabric supported by a metal mesh called a stent. It can be used for a variety of conditions involving the blood vessels, but most commonly is used to reinforce a weak spot (an aneurysm) in an artery.
An Implanted Cardioverter Defibrillator (ICD) is a device that is implanted in a patient’s body to help control the heart’s rhythm. ICDs are extremely effective in stopping dangerous arrhythmias and are the most effective therapy for treating ventricular fibrillation, the major cause of sudden cardiac death. The ICD continuously monitors the heart rhythm and delivers a “pacemaker” shock when the heart rhythm gets too slow. If the heart rhythm gets dangerously fast, the ICD can deliver a life-saving shock that returns the heart to a normal rhythm.
Left Ventricular Assist Device (LVAD)
A Left Ventricular Assist Device (LVAD) is a mechanical device that helps the heart pump blood. Implanted in the patient's abdomen, the device has a small external power supply. Studies have shown LVADs to improve the quality of life for patients with severe heart failure. In the past, LVADs were seen only as a temporary therapy for patients waiting for a heart transplant. Today, however, physicians sometimes look to LVADs as a permanent treatment for patients who are not candidates for heart transplantation.
The heart has a natural “pacemaker” that regulates electrical impulses in the heart. This natural “pacemaker” is called the sinoatrial node. But sometimes the sinoatrial node does not work properly and an artificial pacemaker is needed to regulate the heart’s rhythm. An implantable pacemaker device continuously monitors the rhythm of the heart and transmits electrical impulses to stimulate the heart if it is beating too slowly or unevenly.
Percutaneous Coronary Interventions
Percutaneous coronary interventions are minimally invasive therapeutic procedures for rebuilding and unblocking occluded (clogged) blood vessels. A catheter is inserted through a small puncture in the skin and into a blood vessel. Your physician then uses tiny, camera-guided wires and tools to locate and repair clogged blood vessels through the use of balloon angioplasty, stent insertion, the use of other mechanical devices or specialized lasers.
Percutaneous Valve Repair
Using minimally invasive, catheter-based therapies, our experts can repair abnormalities of the heart's four valves — the mitral, aortic, tricuspid and pulmonic. Percutaneous valve repair procedures can be used to repair narrowed valves and improperly closing valves. In addition to valve repair, the DMC pioneered minimally invasive heart valve replacement. In 2004, one of physicians became one of the first doctors in the United States to use a minimally invasive technique to successfully replace a heart valve.
Vena Cava Filter
This is a small metal device that is temporarily inserted to capture blood clots and prevent them from moving to other areas of the body. The filter allows blood to pass through the vein as it normally would.
An interventional radiologist or vascular surgeon inserts the filter into the vena cava, which is the main vein going back to the heart from your lower body. To reach this vein, which is in the abdomen, the doctor inserts the filter into a leg, neck, or arm vein.