In an ECG, what does the term "Q wave" signify?

In an ECG, what does the term "Q wave" signify?

• A. A normal finding in all ECGs
• B. A pathologic Q wave may indicate a previous myocardial infarction
• C. An indication of pacemaker activity
• D. A sign of atrial enlargement

Answer: (B)

The term "Q wave" in an ECG refers to a specific deflection on the ECG waveform that corresponds to the initial negative deflection of the QRS complex. A pathologic Q wave is particularly significant in clinical practice, as it may indicate that a patient has experienced a previous myocardial infarction (heart attack). When there is damage to the heart muscle due to insufficient blood supply during a myocardial infarction, necrotic tissue can develop, which may manifest as abnormal Q waves on the ECG. These Q waves often suggest that a portion of the heart has been permanently damaged, thus providing crucial information for diagnosis and management of cardiovascular conditions. Identifying pathologic Q waves helps healthcare professionals assess the history of ischemic heart disease in a patient, guiding further investigation and treatment options. This understanding reinforces the importance of correctly interpreting the various components of the QRS complex during ECG analysis.

The term "Q wave" in an ECG refers to a specific deflection on the ECG waveform that corresponds to the initial negative deflection of the QRS complex. A pathologic Q wave is particularly significant in clinical practice, as it may indicate that a patient has experienced a previous myocardial infarction (heart attack). When there is damage to the heart muscle due to insufficient blood supply during a myocardial infarction, necrotic tissue can develop, which may manifest as abnormal Q waves on the ECG. These Q waves often suggest that a portion of the heart has been permanently damaged, thus providing crucial information for diagnosis and management of cardiovascular conditions.

Identifying pathologic Q waves helps healthcare professionals assess the history of ischemic heart disease in a patient, guiding further investigation and treatment options. This understanding reinforces the importance of correctly interpreting the various components of the QRS complex during ECG analysis.