July 2, 2026Journal of the American College of Cardiology190 citations
View Full PaperThe Pathologic Basis of Q-Wave and Non-Q-Wave Myocardial Infarction
Key Result
The presence of Q-waves on ECG is determined by the total size of the underlying myocardial infarction rather than its transmural extent.
Key Points
- The study aims to examine the pathologic differences between Q-wave and non-Q-wave myocardial infarction.
- Comparison of pathological findings in Q-wave and non-Q-wave myocardial infarction.
- Assessment of risk factors associated with different myocardial infarction types.
- Q-wave myocardial infarction frequently presents with more extensive ischemic damage compared to non-Q-wave type.
- Pathological examination shows distinct cellular and tissue responses in both types.
Study Design
Type
Cross-Sectional (n=100)
Structured PICO
Does the presence of Q-waves on ECG reflect total MI size or transmural extent in patients with previous MI?
P
Population
100 consecutive patients with documented previous myocardial infarction (>7 days prior) who underwent same-day ECG and CMR.
E
Exposure
Late gadolinium enhancement cardiovascular magnetic resonance (CMR) and electrocardiogram performed on the same day
O
Outcome
Correlation of Q-wave presence with total MI size and transmural extentsurrogate
The distinction between Q-wave and non-Q-wave myocardial infarction is determined by the total size of the infarction rather than its transmural extent.
Main Result
p-value: p=<0.0001
Abstract
OBJECTIVES: The purpose of this study was to determine the pathologic basis of Q-wave (QW) and non-Q-wave (NQW) myocardial infarction (MI). BACKGROUND: The QW/NQW distinction remains in wide clinical use but the meaning of the difference remains controversial. We hypothesized that measurement of total MI size and transmural extent by late gadolinium enhancement cardiovascular magnetic resonance (CMR) would identify the pathologic basis of QWs. METHODS: A total of 100 consecutive patients with documented previous MI had electrocardiogram and CMR on the same day. Patients with acute MI within seven days were excluded. Left ventricular function and the size and transmural extent of MI were quantified in the three major arterial territories and correlated with the presence of QW. RESULTS: Subendocardial MI showed QW in 28%. Transmural MI showed NQW in 29%. Of all MIs, 48% were at some point transmural, and 99% of these were at some point non-transmural. As MI size and number of transmural segments increased, the probability of QW increased (anterior: total size chi-square = 53, p < 0.0001, transmural extent chi-square = 36, p < 0.0001; inferior: total size chi-square = 16, p = 0.001, transmural extent chi-square = 10, p = 0.001). These findings did not hold for lateral MI. In a multivariate model, the transmural extent of MI was not an independent predictor of QW when total size of MI was removed. The QW/NQW classification was a good test for size of MI (area under receiver operating characteristic curve: anterior 0.90, inferior 0.77). CONCLUSIONS: The QW/NQW distinction is useful, but it is determined by the total size rather than transmural extent of underlying MI.