From the Guidelines
Deep Q waves on an electrocardiogram (ECG) in pediatric patients should be a concern when they appear in leads other than III, aVR, and V1, particularly when they are deep, wide (>0.04 seconds), or present in multiple contiguous leads. When evaluating deep Q waves in pediatric ECGs, it is essential to consider the location, depth, and width of the Q waves, as well as the presence of other electrocardiographic abnormalities. According to the American Heart Association statement 1, electrocardiographic abnormalities, including deep Q waves, can be an early indicator of cardiac involvement in patients with neuromuscular diseases, such as Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). Some key points to consider when evaluating deep Q waves in pediatric patients include:
- Normal physiologic Q waves in children are typically narrow, less than 5mm in depth, and commonly seen in leads III, aVR, and V1.
- Concerning features include Q waves that are deeper than 25% of the R wave amplitude, wider than 0.04 seconds, or present in leads where they are not typically expected.
- The presence of deep Q waves in leads other than III, aVR, and V1, particularly when they are deep, wide, or present in multiple contiguous leads, may indicate serious underlying cardiac conditions such as hypertrophic cardiomyopathy, myocardial infarction, or congenital heart defects.
- If abnormal Q waves are detected, prompt referral to a pediatric cardiologist is warranted for further evaluation, which may include additional imaging studies such as echocardiography, as recommended by the American Heart Association statement 1. Early detection and intervention for underlying cardiac pathology can significantly improve outcomes in pediatric patients with abnormal Q waves.
From the Research
Deep Q Waves in Pediatric ECG
Deep Q waves on an electrocardiogram (ECG) can be a concern in pediatric patients, and it is essential to understand when they may indicate a potential issue.
- The presence of deep Q waves in children can be associated with various heart conditions, including ventricular septal defect, endocardial cushion defect, patent ductus arteriosus, and hypertrophic cardiomyopathy 2.
- A study found that deep Q waves in children were most frequently caused by volume-overload of the left ventricle (35%) and left axis deviation (33.3%), whereas myocardial infarction and septal hypertrophy were less common causes 2.
- The depth of Q waves can be significant, and considering the leads where they are observed, the presence of additional ECG abnormalities, the patient's age, and any relevant clinical information can help narrow down the diagnostic possibilities 3.
Diagnostic Considerations
When evaluating deep Q waves in pediatric patients, it is crucial to consider the following factors:
- The presence of other ECG abnormalities, such as left axis deviation or signs of ventricular hypertrophy 2.
- The patient's clinical history, including any symptoms or diagnoses of heart conditions 2.
- The results of additional diagnostic tests, such as echocardiography or vectorcardiography, which can help identify underlying heart conditions 2.
Clinical Implications
Deep Q waves in pediatric patients can have significant clinical implications, and it is essential to carefully evaluate each patient to determine the underlying cause and appropriate treatment.
- In some cases, deep Q waves may be associated with underlying heart conditions that require medical attention or intervention 2.
- The use of beta-blockers, such as bisoprolol, may be considered in the treatment of certain arrhythmias in pediatric patients, although the evidence for their use in this population is limited 4.