An Electrocardiogram (EKG or ECG) is a non-invasive test that records the heart’s electrical activity. It helps healthcare professionals evaluate heart function by observing the electrical signals that coordinate its contractions. While an “abnormal” EKG can be concerning, it often signals the need for further investigation rather than a severe problem.
Understanding EKG Basics
An EKG measures the heart’s electrical impulses as they travel through the heart muscle. These impulses dictate the heart’s rate, rhythm, and strength of each beat. During the test, small electrodes are placed on the skin of the chest, arms, and legs. These detect the electrical changes that occur with each heartbeat. The EKG machine translates these signals into a wavy line pattern, displayed on a screen or printed for interpretation, allowing medical professionals to identify deviations from normal electrical patterns.
Specific Abnormal EKG Findings and Their Implications
An EKG can reveal various abnormalities in the heart’s electrical activity or suggest structural changes. Heart rate abnormalities include tachycardia (heart beats too fast, over 100 bpm at rest) or bradycardia (heart beats too slowly, under 60 bpm at rest). Tachycardia can reduce blood flow, while severe bradycardia can lead to insufficient blood supply to the brain and body.
Rhythm abnormalities, also known as arrhythmias, involve irregular heartbeats. These range from premature beats (extra or early heartbeats) to complex conditions like atrial fibrillation. Atrial fibrillation is characterized by a rapid, irregular rhythm in the heart’s upper chambers, often leading to an irregular pulse and absent P waves on the EKG.
Conduction abnormalities indicate problems with electrical signals moving through the heart’s specialized pathways. Heart blocks, for example, occur when electrical signals are delayed or completely blocked as they travel from the upper to the lower chambers. This can result in slower heart rates or an uncoordinated pumping action. Bundle branch blocks are another type of conduction abnormality where electrical signals are delayed in either the right or left bundle branches, causing one ventricle to contract slightly slower than the other.
An EKG can also provide clues about structural changes within the heart. Left ventricular hypertrophy (LVH) suggests an enlargement or thickening of the left ventricle. This can manifest as increased R wave amplitude and deep S waves on the EKG. Additionally, the EKG can show signs of reduced blood flow to the heart muscle (ischemia) or damage from a past heart attack (infarction). Ischemia might appear as ST-segment depression or T-wave inversions, while an infarction can show significant Q waves or ST-segment elevation.
Underlying Causes of Abnormal EKG Readings
Abnormal EKG readings stem from various factors, encompassing both cardiac conditions and non-cardiac influences. Heart conditions are a frequent cause, such as coronary artery disease, where arteries supplying the heart narrow, often leading to ischemia and EKG changes. A previous heart attack can leave lasting electrical changes, resulting in abnormal EKG patterns. Conditions like heart failure, cardiomyopathy, and high blood pressure can also alter the heart’s structure and function, impacting EKG readings.
Beyond cardiac issues, several non-cardiac factors can contribute to an abnormal EKG. Imbalances in electrolytes, such as potassium, sodium, and calcium, can disrupt the heart’s electrical activity. Certain medications, particularly those affecting heart rhythm or blood pressure, may also influence EKG results.
Stress, anxiety, and the use of substances like alcohol or certain drugs can temporarily affect heart rate and rhythm, leading to EKG variations. Underlying lung conditions or technical errors during the EKG test can sometimes produce an abnormal reading. Some “abnormalities” can also be normal variations for certain individuals, such as athletes who often have a lower resting heart rate.
What Happens After an Abnormal EKG
An abnormal EKG result often serves as a starting point for further investigation rather than a definitive diagnosis of a severe condition. The first step is to discuss the findings with a healthcare professional, typically a cardiologist, who can interpret the results in the context of your overall health and symptoms.
To pinpoint the exact cause, additional testing is frequently recommended. These follow-up tests might include an echocardiogram (which uses sound waves to image heart structure and function), a stress test (which monitors heart activity during physical exertion), or a Holter monitor.
A Holter monitor is a portable EKG device worn for a day or more to record heart activity, especially for symptoms that come and go. Blood tests may also be ordered to check for electrolyte imbalances or other medical conditions. Depending on the diagnosis, treatment may involve watchful waiting, lifestyle modifications, or prescription medications.