Electrocardiograms (EKG or ECG) and Echocardiograms are often confused because their names sound similar. While both are non-invasive diagnostic tools used to assess heart health, they measure fundamentally different aspects of heart function. The EKG focuses on the heart’s electrical system, recording the timing and strength of electrical signals. The Echocardiogram, conversely, uses ultrasound technology to create moving images of the heart’s physical structure and mechanical performance.
Understanding the Electrocardiogram
The Electrocardiogram (EKG or ECG) is a quick test that captures the heart’s electrical activity. Electrical impulses generated within the heart spread through the muscle, causing it to contract and pump blood. The EKG machine measures these impulses as voltage changes on the skin’s surface, typically using ten electrodes placed on the chest and limbs.
The resulting tracing displays a characteristic wave pattern representing the orderly progression of electrical activity within the heart. Clinicians analyze this pattern to determine the heart rate and rhythm, looking for irregularities known as arrhythmias. The EKG can also provide evidence of damage to the heart muscle, such as that caused by a past or current heart attack, by detecting changes in the signal’s strength and timing.
Understanding the Echocardiogram
The Echocardiogram, often called an “Echo” or cardiac ultrasound, uses sound waves to create a real-time, moving picture of the heart. It employs a transducer that sends high-frequency sound waves into the chest. These waves bounce off the heart structures and are captured by the transducer to construct an image on a monitor.
The information gathered from an Echo is structural and mechanical, showing the physical state and function of the heart. The test allows doctors to visualize the size and shape of the four heart chambers and the thickness of the heart walls. It also provides a detailed look at the heart valves, assessing whether they open and close properly. A key measurement is the ejection fraction, which indicates the heart muscle’s overall strength by measuring the percentage of blood pumped out with each beat.
How the Patient Experience Differs
The physical experience of undergoing an EKG is markedly different from that of an Echocardiogram, starting with the duration of the tests. An EKG is a rapid procedure, typically lasting only five to ten minutes, with most of that time spent applying the sticky electrodes to the skin. The patient lies still while the machine records the electrical data; no gel or extensive preparation is required.
The Echocardiogram, by contrast, is a longer examination that usually takes between 20 and 60 minutes to complete. During the Echo, a technician first applies a cool, water-based gel to the patient’s chest to help the ultrasound waves travel efficiently. The technician then presses and moves a handheld transducer across the chest, often requiring the patient to change position, such as lying on their left side, to capture various angles of the heart.
When Doctors Order Each Test
The decision to order an EKG, an Echocardiogram, or both, depends on the patient’s symptoms and the specific information the doctor needs. An EKG is often the first test performed when symptoms suggest an electrical issue, such as heart palpitations, dizziness, or fainting, as it can immediately diagnose an irregular heartbeat or arrhythmia. It is also routinely used to investigate sudden chest pain, as the electrical tracing can quickly identify patterns consistent with reduced blood flow or muscle damage from a heart attack.
Doctors order an Echocardiogram when structural or mechanical problems are suspected, such as a heart murmur heard during a physical exam or symptoms like shortness of breath and leg swelling, which may signal heart failure. The Echo is the definitive tool for assessing the heart’s pumping efficiency, checking for damage to the heart valves, or diagnosing congenital heart defects.