Incidence and prognosis of non-Q-wave vs. Q-wave myocardial infarction following catheter-based reperfusion therapy

In Comparison to Pathological Q Waves, Selvester Score is a Superior Diagnostic Indicator of Increased Long-Term Mortality Risk in ST Elevation Myocardial Infarction Patients Treated with Primary Coronary Intervention

The development of pathological Q waves has long been correlated with worsened outcome in patients with ST elevation myocardial infarction (STEMI). In this study, we investigated long-term mortality of STEMI patients treated by primary percutaneous coronary intervention (PPCI) and compared predictive values of Q waves and of Selvester score for infarct volume estimation. Data of 283 consecutive STEMI patients (103 females) treated by PPCI were analysed. The presence of pathological Q wave was evaluated in pre-discharge electrocardiograms (ECGs) recorded ≥72 h after the chest pain onset (72 h Q). The Selvester score was evaluated in acute ECGs (acute Selvester score) and in the pre-discharge ECGs (72 h Selvester score). The results were related to total mortality and to clinical and laboratory variables. A 72 h Q presence and 72 h Selvester score ≥6 was observed in 184 (65.02%) and 143 (50.53%) patients, respectively. During a follow-up of 5.69 ± 0.66 years, 36 (12.7%) patients died. Multivariably, 72 h Selvester score ≥6 was a strong independent predictor of death, while a predictive value of the 72 h Q wave was absent. In high-risk subpopulations defined by clinical and laboratory variables, the differences in total mortality were highly significant (p < 0.01 for all subgroups) when stratified by 72 h Selvester score ≥6. On the contrary, the additional risk-prediction by 72 h Q presence was either absent or only borderline. In contemporarily treated STEMI patients, Selvester score is a strong independent predictor of long-term all-cause mortality. On the contrary, the prognostic value of Q-wave presence appears limited in contemporarily treated STEMI patients.

Pathological Q wave as an indicator of left ventricular ejection fraction in acute myocardial infarction

Background: Q-wave myocardial infarction (QMI) has higher mortality and lower myocardial viability than non-Q-wave myocardial infarction (NQMI), suggesting the existence of pathological Q waves reflects the worse ventricular function. The aim of the study is to determine difference in left ventricular ejection fraction (LVEF) between QMI and NQMI.Methods: The study design was cross-sectional analysis conducted in patients with AMI that were hospitalized and undergone echocardiography in Abdul Wahab Sjahranie County General Hospital Samarinda during February 2014 to March 2015. Standard 12-lead electrocardiograms (ECG) were recorded at presentation, 1 day and 2 days after the onset of AMI as well as using the classical criteria for pathological Q wave. LVEF assessment was performed using echocardiography after the second day since the onset of AMI. Independent-T test was used to determine difference in LVEF using PSPPIRE 0.8.4.Results: There were 34 subjects comprising 16 QMI patients and 18 NQMI patients.  QMI had a lower LVEF (42±13%) compared to NQMI (60±11%, p<0.001). The presence of pathological Q waves was associated with LVEF ≤40% (p=0.002).Conclusion: QMI had a lower LVEF than NQMI, provides information about the role of pathological Q wave as an indicator of LVEF.

Non-Q-wave myocardial infarction: comprehensive analysis of electrocardiogram, pathophysiology, and therapeutics

Since the invention of electrocardiogram (ECG or EKG), its significance in the diagnosis of acute ischemic disease, chronic ischemic disease, and its contribution to cardiology has been no less than remarkable. The pathophysiology of acute coronary syndromes in most cases correlates with the clinical outcomes, biochemical findings (cardiac biomarkers), and electrocardiographic patterns. Electric activity in the myocardium is registered in the ECG describing positive deflections when the depolarization potential orientates positive charges to the recording electrode (approaches to it) and negative deflections when the depolarization potential orientates negative charges to the recording electrode and gets away from it. The abnormal Q-wave is the cornerstone of the myocardial infarction diagnosis after several days of the ischemic event. Findings in the ECG suggestive of ischemia and necrosis are ST elevation/depression and deep Q-waves, respectively, and the presence of a deep abnormal Q-wave in the ECG is evidence of necrotic areas and an inert myocardium, which is not capable to depolarize. Non-Q-wave myocardial infarction has been defined as acute myocardial infarction without a new-onset deep Q-wave on the ECG after day(s) of evolution, and because of the anatomopathological concept of infarction is usually related to necrosis, it results paradoxical to consider this widely known clinical and biochemical entity as a myocardial infarction when there is no evidence of necrosis in the ECG.