What an EKG Measures
An electrocardiogram — EKG or ECG — records the electrical activity of your heart. Small electrodes placed on your chest, arms, and legs detect the tiny electrical impulses that trigger each heartbeat and display them as waveforms on a printout. The test takes about five minutes and is completely painless.
What an EKG is excellent at: detecting arrhythmias (abnormal heart rhythms), identifying whether you've had a recent or previous heart attack by looking at changes in the electrical pattern, and diagnosing conduction disorders — problems with how electrical signals travel through the heart.
What an EKG cannot tell you: the size, structure, or pumping function of your heart. An EKG gives you no information about whether your heart valves are working properly, how thick your heart walls are, or how effectively your left ventricle is squeezing blood out with each beat. A patient can have severe structural heart disease and a perfectly normal-looking EKG.
What an Echocardiogram Shows
An echocardiogram uses ultrasound — high-frequency sound waves — to create real-time images of your heart in motion. Think of it as an ultrasound for the heart, the same technology used in obstetric imaging but directed at your cardiac anatomy.
A standard echocardiogram (technically a transthoracic echocardiogram, or TTE) shows the actual structure and function of your heart: the size of the four chambers, the thickness of the heart walls, how well each valve opens and closes, the direction and velocity of blood flow through the heart, and most critically — your ejection fraction, which is the percentage of blood pumped out with each contraction.
Ejection fraction is the single most important number in cardiology for assessing heart failure. A normal ejection fraction is 55–70%. Below 40% indicates significant heart failure. An EKG cannot tell you this number. Only an echocardiogram can.
Which Test Do You Actually Need?
Most patients who are evaluated for heart concerns should eventually have both. But the tests serve different purposes at different points in the diagnostic process.
An EKG is typically the first test ordered — it's fast, inexpensive, and available everywhere. If your doctor suspects you're having a heart attack, an arrhythmia, or a conduction abnormality, an EKG is the appropriate first step. It's also used as a routine baseline in patients with known heart disease.
An echocardiogram is the appropriate test when the question is about heart structure or function — if you have symptoms of heart failure (shortness of breath, leg swelling, fatigue), if a murmur has been detected and needs evaluation, if you've been diagnosed with high blood pressure and your doctor wants to assess its impact on your heart, or if you have a family history of cardiomyopathy.
The important point: a normal EKG does not rule out structural heart disease. Many patients with significant cardiomyopathy or valvular disease have normal EKGs. If you've had an EKG but are still experiencing symptoms, an echocardiogram is the appropriate next step.
Getting an Echocardiogram Without the Wait
Traditional echocardiograms require a physician referral, a cardiology appointment that may be weeks away, and a hospital or clinic visit. At BlackPoint Diagnostics, you can access a hospital-quality echocardiogram without a referral, without the wait, and at your home or workplace. Every study is reviewed by a board-certified cardiologist and results are delivered in 24–48 hours.
