In-Hospital Cardiovascular Services
In-Hospital Cardiovascular Services
An electrophysiology (EP) study is a test performed to assess your heart’s electrical system or activity and is used to diagnose abnormal heartbeats or arrhythmia. The test is performed by inserting catheters and then wire electrodes, which measure electrical activity, through blood vessels that enter the heart.
Radiofrequency catheter ablation is a technique used to treat arrhythmia, an abnormal heart rhythm created by a disturbance in the heart’s electrical system. Catheter ablation destroys or disrupts parts of the electrical pathways causing the arrhythmias. This is a minimally invasive technique.
Cardioverter Defibrillator Implantation
Treatment for abnormal heart rhythms is also possible with an ICD, or implantable cardioverter defibrillator. An ICD is an electronic device that constantly monitors your heart rate and rhythm. When it detects a very fast, abnormal heart rhythm, it delivers energy to the heart muscle. This causes the heart to beat in a normal rhythm again.
Transesophageal Echocardiography (TEE)
Occasionally a very detailed picture of the heart is difficult to obtain using a standard echocardiogram study. This occurs because ultrasound is often scattered through bone, muscle and lung tissue. TEE is a test in which an ultrasound probe is gently inserted into a patient’s esophagus and stomach to obtain a detailed picture of the heart. Because the ultrasound beam doesn’t have to pass through the chest wall, extremely accurate details of the heart structures are seen. TEE is especially useful for locating heart valve infections and for identifying the presence of a clot inside the heart chambers.
Patients receiving a transesophageal echocardiogram are instructed not to eat or drink anything for eight hours prior to the test. Prior to insertion of the ultrasound probe, a numbing spray is given to the back of the throat to minimize the gag reflex. Then mild to moderate sedation with intravenous medications is given for patient comfort. The test generally takes about 30 minutes. Although this procedure is usually very safe, there is a small risk of minor throat irritation, breathing difficulties, heart rate slowing and aspiration. Perforation or tear of the esophagus is extremely rare.
This is another testing modality used to diagnose the presence and extent of coronary artery disease using ultrasound technology. The patient is stressed either with exercise or chemically with Dobutamine. Ultrasound pictures of the heart are obtained prior to and at the peak of the exercise. Patients with significant coronary artery disease show worsening of the heart’s ability to pump with exercise. Often, part of the heart wall will not be contracting normally compared to the rest of the heart wall. This test is useful for patients who cannot tolerate a nuclear stress test.
Tilt Table Testing
A tilt table test is used to diagnose vasovagal or neurally-mediated syncope (passing out or loss of consciousness). There are many causes of syncope and determining neurally-mediated syncope is important as there are specific treatments available for this type. The patient is kept in a standing position for about 1/2 to 1 hour. During this time, the heart rate and blood pressure are monitored. Patients with neurally-mediated syncope often display exaggerated heart rate slowing and blood pressure decrease during the test. To prepare for the test, patients should withhold medications and not eat or drink after midnight on the day of the exam.
Cardiac Catheterization and Percutaneous Coronary Intervention
This is an invasive test and is considered the gold standard to evaluate for coronary artery disease. After being brought to the catheterization room, the patient is given a mild sedative for comfort. After adequate sedation, the groin (or occasionally the arm) is prepared in a sterile manner. The catheterization site is then numbed using a local anesthetic introduced with a small needle syringe containing lidocaine. After adequate local anesthesia, a plastic sheath is inserted into the artery.
Through this sheath, a long plastic tube, the size of a spaghetti noodle in inserted. Using special X-ray equipment, the catheter or tube is placed into selected areas in the heart and coronary arteries. Dye is injected to determine the location and severity of blockages in the coronary arteries. If a severe blockage is noted, recommendations for revascularization procedures such as angioplasty (opening the blockage using a balloon), stent placement (inserting a metal tube in the site of blockage), or bypass surgery are made. In addition, cardiac catheterization allows measurement of the heart function and of the pressures inside the heart chambers and lungs. This is useful to determine the presence of congestive heart failure, valvular heart disease and lung disease.
To prepare for the procedure, the patient is instructed not to not eat or drink anything after midnight the day of the procedure. Occasionally, IV fluid is given for hydration. For patients with kidney problems, a special medication is given the day before to protect kidney function. Patients are instructed to withhold certain medications both before and after the catheterization.
The procedure generally takes about an hour. After completion, the tube and sheath are removed. A plugging device may be used to reduce bed rest duration after the catheterization. Routine bed rest for few hours is required to minimize bleeding and to avoid injury to the catheterization site. Because of the sedation, the patient cannot drive until the next day. Mild discomfort and discoloration may be noted in the catheterization site after the procedure.
Diagnostic Peripheral Angiography and Intervention
Invasive Hemodynamic Monitoring
Occasionally, patients may become very sick and require treatment in an intensive care unit. They may have low urine output and low blood pressure and have trouble with oxygenation. At times, it becomes difficult to assess their volume status (whether they have too much or too little fluid in the body). Invasive monitoring with a Swan-Ganz Catheter may be useful for obtaining further information. Typically, a sheath is inserted in a patient’s central vein. Using this sheath, a long, balloon tipped catheter is inserted and “floated” through the heart to allow accurate pressure measurements in the heart. Complications include irregular heart rhythms, bleeding and infection.
Patients who have a condition called atrial flutter or atrial fibrillation, characterized by an irregular heartbeat, can undergo a procedure called a cardioversion to restore their normal cardiac rhythm. Patients who have been on adequate doses of a blood thinner (Coumadin/warfarin) for at least 3-4 weeks can safely undergo this procedure, which consists of moderate sedation under the supervision of the cardiologist and/or anesthesiologist, after which a brief electrical shock is delivered to the heart through electrical pads placed on the thorax. This process can “jolt” the heart back to a normal rhythm. Patients are observed for a brief period and usually go home on the same day of the procedure.
Permanent Pacemaker Implantation
Patients may experience dizziness, shortness of breath, weakness or syncope (passing out) due to either a very slow heart rate or heart block (inability of the electrical system of the heart to conduct properly). For patients with these symptoms, insertion of a pacemaker is advised. A pacemaker consists of a battery pack and electrode wires. The battery pack is approximately the size of a silver dollar and is placed under the skin on the left upper chest.
Patients are instructed not to eat or drink after midnight on the day of the procedure. During the procedure, patients are given intravenous sedation for comfort. After adequate local anesthesia, a small incision is made in the left upper chest. Through the incision, the subclavian vein (large vein that travels to heart) is located. Using x-ray guidance, a wire is inserted through the subclavian vein. The tip of the wire is attached to the heart muscle, while the end is attached to the battery pack. Once the wires are attached, the incision is closed. The risks of the procedure are generally low under experience hands. Risks usually include problems with sedation, bleeding, and infection. Occasionally the lung may be punctured, requiring either close observation or re-expansion with a chest tube. Patients are kept overnight for observation.