Because an EKG measures so many different aspects of the heart’s function, abnormal results can signify several issues. These include:

1.     Defects or abnormalities in the heart’s shape and size: An abnormal EKG can signal that one or more aspects of the heart’s walls are larger than another. This can signal that the heart is working harder than normal to pump blood.
2.     Electrolyte imbalances: Electrolytes are electricity-conducting particles in the body that help keep the heart muscle beating in rhythm. Potassium, calcium, and magnesium are electrolytes. If your electrolytes are imbalanced, you may have an abnormal EKG reading.
3.     Heart attack or ischemia: During a heart attack, blood flow in the heart is affected and heart tissue can begin to lose oxygen and die. This tissue will not conduct electricity as well, which can cause an abnormal EKG. Ischemia, or lack of blood flow, may also cause an abnormal EKG.
4.     Heart rate abnormalities: A typical human heart rate is between 60 and 100 beats per minute (bpm). An EKG can determine if the heart is beating too fast or too slow.
5.     Heart rhythm abnormalities: A heart typically beats in a steady rhythm. An EKG can reveal if the heart is beating out of rhythm or sequence.
6.     Medication side effects: Taking certain medications can impact a heart’s rate and rhythm. Sometimes, medications given to improve the heart’s rhythm can have the reverse effect and cause arrhythmias. Examples of medications that affect heart rhythm include beta-blockers, sodium channel blockers, and calcium channel blockers. Learn more about arrhythmia drugs.