From the Guidelines
The downward deflection of lead II and upward deflection of aVR in a 12-lead ECG is most likely due to incorrect electrode placement, specifically reversed left and right arm electrodes, which should be corrected immediately to ensure accurate ECG interpretation. This finding is abnormal since lead II normally shows an upright P wave, QRS complex, and T wave, while aVR typically displays predominantly negative deflections 1. The American Heart Association, American College of Cardiology, and Heart Rhythm Society recommend standardization and interpretation of the electrocardiogram, emphasizing the importance of correct lead placement for accurate diagnosis 1.
Some key points to consider in this scenario include:
- Correct electrode placement is crucial for accurate ECG interpretation
- Reversed limb lead placement can mimic pathological conditions, making it essential to rule out technical errors before making a diagnosis
- If the finding persists after confirming correct lead placement, it may represent conditions such as dextrocardia, ventricular tachycardia with a rightward superior axis, or severe right ventricular strain
- The underlying electrophysiological basis relates to the direction of electrical depolarization being opposite to what is normally expected, causing the recording electrodes to detect voltage changes in reversed polarity 1.
In clinical practice, it is essential to prioritize the correction of technical errors, such as incorrect electrode placement, to ensure accurate ECG interpretation and prevent misdiagnosis. The most recent and highest quality study, as recommended by the American Heart Association, American College of Cardiology, and Heart Rhythm Society, should be consulted for guidance on ECG interpretation and standardization 1.
From the Research
Implication of Downward Deflection of Lead II and Upward Deflection of AVR in a 12L ECG
- The provided studies do not directly address the implication of downward deflection of lead II and upward deflection of AVR in a 12L ECG.
- The studies focus on the use of aspirin in patients with acute myocardial infarction, cardiogenic shock, and ischemic heart disease 2, 3, 4, 5, 6.
- There is no mention of ECG readings or the specific implications of lead II and AVR deflections in the provided studies.
- Therefore, there are no research papers to assist in answering this question based on the provided evidence.