Key result
Isolated V1-V2 QS complexes unreliably indicate septal infarction, with confirmed MI in only ~33%.
Why the study?
Does the presence of QS complexes in leads V1 and V2 without other ECG abnormalities reliably indicate prior myocardial infarction or clinical coronary disease?
Population
198 patients, comprising 99 cases with QS deflections in both leads V1 and V2 but no other ECG abnormality…
Comparison
Presence of QS deflections in leads V1 and V2… vs Entirely normal ECGs
Design
Case-control
Authors
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Isolated QS in V1-V2 should not prompt MI diagnosis in isolation; supports lead-placement artifact and leaves open prospective validation of ECG criteria.
Case-Control (n=198)
No
Does the presence of QS complexes in leads V1 and V2 without other ECG abnormalities reliably indicate prior myocardial infarction or clinical coronary disease?
Absolute Event Rate: 32.8% vs 18.9%
p-value: p=<0.05
QS complexes in leads V1 and V2 without other ECG abnormalities are most often an artifact of lead placement and indicate prior myocardial infarction in only a minority (~20%) of cases.
Rex N. MacAlpin (2004) conducted a case-control in QS complexes in leads V1 and V2 without other ECG abnormalities (n=198). Isolated QS complexes in leads V1 and V2 vs. Entirely normal ECGs was evaluated on Documented clinical or imaging evidence of myocardial infarction (p=<0.05). Isolated QS complexes in leads V1 and V2 without other ECG abnormalities are an unreliable sign of septal infarction, with clinical or imaging evidence of myocardial infarction present in only 32.8% of cases compared to 18.9% of controls.
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