Baseline Wander in ECG

Introduction

Baseline wander is a common artifact in electrocardiography (ECG) that can interfere with the accurate interpretation of heart rhythms. It appears as a slow, undulating shift of the baseline, which can mimic or obscure significant cardiac abnormalities.

Causes of Baseline Wander

Baseline wander can be caused by both physiological and technical factors:

1. Respiratory Movements - Deep breathing or irregular respiration can cause slow shifts in the baseline.
2. Patient Movement - Muscle activity, shifting position, or tremors can introduce slow drifts in ECG recordings.
3. Poor Electrode Contact - Loose electrodes or dry electrode gel can cause signal instability.
4. Electrical Interference - External electrical sources or improper grounding of the ECG machine can contribute to baseline shifts.
5. Skin and Electrode Impedance - High skin resistance due to improper skin preparation can increase baseline fluctuations.

How to Reduce Baseline Wander

Patient-Related Corrections

• Instruct the patient to remain still and breathe normally during ECG recording.
• Ensure the patient is lying in a stable and comfortable position.

Technical Adjustments

• Proper Electrode Placement: Clean the skin, remove excess hair, and apply fresh electrode gel.
• Use High-Quality Electrodes: Old or dry electrodes should be replaced.
• Adjust Filtering Settings: Modern ECG machines have baseline filtering algorithms to reduce movement artifacts.
• Check the Equipment Grounding: Ensure all ECG machines are properly grounded to minimize electrical interference.

Clinical Importance of Managing Baseline Wander

Uncorrected baseline wander can: - Mask significant ECG abnormalities such as ST-segment elevation or depression. - Cause inaccuracies in automated ECG interpretation by machines. - Lead to misdiagnosis or delay in the detection of critical cardiac events.

Understanding and minimizing baseline wander improves the accuracy of ECG readings, aiding in better patient diagnosis and management.

Source recommendations

1. American Heart Association Guidelines for Electrocardiography

1. https://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack/electrocardiogram-ecg-or-ekg
2. https://www.ahajournals.org/doi/10.1161/circulationaha.108.191095
3. https://pubmed.ncbi.nlm.nih.gov/19281932/
4. https://www.ahajournals.org/doi/10.1161/circulationaha.106.180200
5. https://elearning.heart.org/course/1211

2. European Society of Cardiology Guidelines on ECG Interpretation

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines
2. https://pubmed.ncbi.nlm.nih.gov/12269267/
3. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Neonatal-Electrocardiogram-Guidelines-for-the-interpretation-of-the
4. https://academic.oup.com/eurheartj/article-abstract/39/16/1466/2965923
5. https://www.escardio.org/Guidelines