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Diagnosing Cardiac Arrhythmias at McLaren Port Huron

At McLaren Port Huron, the cardiology team will utilize a wide variety of state of the art technologies and proven test to diagnosis cardiac rhythm disorders.  Through testing we are able to locate the source of electrical disturbances in the heart and provide precise treatment and improved outcomes. 

These tests include:

Click for larger imageElectrocardiogram

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.



An echocardiogram is a specialized ultrasound machine that creates a video image of the beating heart. This non-invasive test is often used to identify problems with heart muscle and valves.

Image of standard echocardioagramImage of echocardioagram

Another type of echocardiogram is a transesophageal echocardiogram also referred as a TEE.  This test may be recommended to evaluate different structures in the heart such a valves or blood clots.  The esophagus sits behind the heart and by advancing the echo transducer down the esophagus common obstructions are avoided such as the lungs and ribs.  This provides clearer images.  

Image of transesophageal EchoImage of transesophageal Echo or TEE

Monitoring Devices

Monitoring devices may be used to detect irregular heart rhythms over different periods of time.

Holter Monitoring

Patient wearing a holter monitorHolter monitoring devices are portable ECG recorders that the patient wears during normal daily activities for typically 24 hours.  The device will make a detailed record of the heart’s activities.  It will help the doctor correlate symptoms with the heart rate.  The recording last for 24 hours compared to an EKG that takes less than 1 minute.

Loop Recorder

A loop recorder is a small device placed under the skin to help identify causes of fainting.  Certain heart disorders can cause fainting, such as abnormal heartbeats.  The device continuously records heart activity similar to an EKG for up to 2 years.  The recording can evaluate by the doctor to determine the appropriate treatment.

Tilt Table Test

The Tilt Table Test is used to determine a cause of syncope (fainting or loss of consciousness). There can be different reasons people experience syncope. For some people it is related to an abnormal nervous system reflex causing the heart to slow and the blood vessels to dilate (open up) lowering the blood pressure. When this happens there is a reduced amount of blood to the brain causing one to faint. This type of syncope is called vasovagal, neurocardiogenic or abnormal vasoregulatory syncope and is considered benign (not dangerous or life-threatening), except for the injuries that can happen when one faints unexpectedly.
The Tilt Table Test is performed to reproduce (bring on) symptoms of syncope while the person is being closely monitored.

Electrophysiology Test (EPS)


During this test electrodes are inserted into the veins in the groin and/or chest and positioned in the heart.  The patient is given medication to relax during the procedure.  The test measures the heart’s electrical conduction system,  During the test, electrical impulses are applied to the heart top cause a fast heart rate and locate arrhythmias.  If an arrhythmia is induced, the physician may try to control it during the procedure with medications, pacing electrodes, defibrillation or catheter ablation.

3D Cardiac Map

Image of 3D cardiac mapping test result

During 3D Cardiac Mapping, a precise location of the arrhythmia is located.  This is not required for all arrhythmias.  The cardiac map reconstructs the mapping catheter and local electrograms in a three-dimensional in real-time.  The image is color-coded with relevant electrophysiology information.



Nuclear Cardiac Stress Test

Nuclear Cardiac Stress Test

Nuclear stress test help to accurately diagnose blockages in the Nuclear Cardiac Stress Testarteries of the heart, recognize the presence of prior heart attacks, assess the pumping function of the heart and predict the chance of future heart attacks.

Nuclear stress tests are non-invasive and usually take 4 to 5 hours. During the test, the patient receives a small and harmless injection of a radioactive substance. The substance is visible to a special camera, enabling the nuclear imaging specialist to take clear pictures of the heart and its blood flow. Pictures of the heart are first taken with the patient at rest. Then, the patient exercises on a treadmill and additional images of the heart are taken and compared to the "at-rest" images.

If the patient is unable to exercise, special drugs can be administered to simulate exercise conditions. Using this technique, the physician can identify areas of decreased blood supply to the heart that might indicate prior heart muscle damage or significant coronary artery blockages.

The skill and expertise of the nuclear imaging specialist are extremely important in interpreting these images. A cardiologist can use the results of the nuclear stress test to choose the best form of treatment for a patient.

Nuclear test of the heart used in diagnosing heart issues.