Can An ECG Detect Congenital Heart Disease?

Electrocardiograms (ECGs) are commonly used to assess the electrical activity of the heart, helping to identify irregularities in heart rhythm and conduction pathways. However, when it comes to diagnosing congenital heart defects, the primary diagnostic tool is typically echocardiography, which provides a detailed view of the heart's structure, chamber size, and valve function. Congenital heart disease (CHD) primarily involves structural abnormalities present from birth, making cardiac ultrasound the gold standard for diagnosis.

How ECG Relates to Congenital Heart Conditions

Despite not being the first-line diagnostic method for structural heart defects, an ECG can still play a supportive role in identifying signs of congenital heart issues. If a structural defect affects the heart's electrical conduction system, these changes may appear on an ECG. For example, conditions such as pulmonary stenosis, atrial septal defect, pulmonary hypertension, or abnormalities of the tricuspid valve can lead to right ventricular hypertrophy.

Recognizing Right Ventricular Hypertrophy on ECG

Right ventricular hypertrophy often results in increased R wave amplitude in the right precordial leads on an ECG. This pattern can indicate that the right ventricle is working harder than normal, possibly due to an underlying congenital condition. In mild cases, patients may not experience any noticeable symptoms, and the condition might only be discovered incidentally during routine testing.

ECG in Diagnosing Right-Sided Heart Anomalies

One specific congenital anomaly that can be identified through ECG is dextrocardia, a condition in which the heart is located on the right side of the chest. In this case, the heart's orientation mirrors that of a normal heart, with reversed positions of the atria, ventricles, and major blood vessels. This condition, often referred to as "mirror-image dextrocardia," is sometimes accompanied by situs inversus, where other internal organs are also reversed. An ECG can reveal characteristic findings that help confirm this diagnosis, making it a valuable tool when combined with imaging studies.

While echocardiography remains the most reliable method for detecting structural heart defects, ECGs can provide important clues about underlying congenital conditions that affect the heart's electrical system. Therefore, in a comprehensive cardiac evaluation, both tests may be used together to ensure a complete understanding of the patient's heart health.