Electro Cardiology Services
Cardiac stress testing assesses the heart for coronary artery disease by attaching the patient to a special EKG machine and then speeding the heart up by either walking on a treadmill or by giving the patient a stress test drug that mimics exercise if they cannot walk on a treadmill.
Usually images of the heart are taken with a nuclear camera or with an ultrasound machine before and after the stress test is performed. These images are compared later to see if there has been a change in cardiac perfusion or heart muscle contractility. The EKG tracings are also examined for evidence of cardiac ischemia during the exam. Cardiac ischemia is essentially heart muscle that is starved of oxygen from a decrease in arterial blood flow. An electrocardiogram (EKG) is a tracing of the hearts electrical activity. This tracing or wave form is drawn on graph paper. The physician analyzes the tracing to determine if the heart is functioning normally.
Regular treadmill stress test: The patient will be hooked up to a special EKG machine. The patient is then placed on a treadmill. The treadmill will start off very slow and every three minutes it will increase its speed and elevation. The patient will stay on the treadmill until their heart rate reaches a predetermined limit which is calculated based on age. The patients EKG is monitored while they are on the treadmill. Blood pressure is also monitored while on the treadmill. Once the predetermined heart rate is reached the patient is taken off the treadmill and recovered for a few minutes. The EKG tracing that were acquired while the patient was on the treadmill are then read by a physician and a report is sent to the ordering physician.
Nuclear stress test: A nuclear stress test uses a radioactive tracer that is injected into a vein to image the heart. Pictures of the heart are taken before you exercise and again after you are done exercising with a nuclear camera. These images are then compared to determine if there was a change in cardiac muscle perfusion. The patient’s EKG and blood pressure are monitored during the exam and a physician will look at the EKG and the nuclear images to determine if there is evidence of coronary artery disease.
Stress echocardiogram: A stress echocardiogram uses ultrasound images of the heart to look for evidence of cardiac ischemia. Ultrasound images of the heart are taken before and after exercise and then compared to determine if there was a change in the way the heart muscle thickens. The patient’s EKG and blood pressure are monitored during the exam and a physician will look at the EKG and the ultrasound images to determine if there is evidence of coronary artery disease.
Chemical stress tests: Chemical stress tests are used for patients that cannot walk on a treadmill. Lexiscan and Dobutamine are most commonly used in our institution. Lexiscan and Dobutamine are used in place of the treadmill. Dobutamine speeds the heart up and mimics exercise while Lexiscan dilates the coronary arteries and increases perfusion of the cardiac muscle.
Electrocardiogram (EKG)
An electrocardiogram is a tracing of the heart’s electrical activity. The tracing helps they physician determine if the heart is functioning normally. This exam is often ordered for patients complaining of chest pain, palpitations or an irregular heartbeat. EKG’s can find evidence of a heart attack or an irregular heart rhythm.
Holter Monitors
A holter monitor is a miniature version of an EKG machine. Holter monitors can diagnose cardiac arrhythmias (irregular heart beats) by recording digital information during a 24 – 72 hour time frame.
Event Monitors
An event monitor is a miniature version of an EKG machine. Event monitors can diagnose cardiac arrhythmias (irregular heart beats) that occur infrequently. The monitor stores EKG rhythm strips digitally and usually is worn for 30 days at a time.