Lack of Pathologic Q Waves: A Specific Marker of Viability in Myocardial Hibernation

Abstract

Background: The present study evaluates the lack of Q waves on the electrocardiogram (ECG) in the prediction of myocardial viability compared with dobutamine stress echocardiography (DSE) and rest-redistribution thallium-201 (Tl-201) scintigraphy. Hypothesis: The lack of pathologic Q waves (NoQ) may be a readily available and specific marker for the presence of viability. Methods: Sixty four patients with stable coronary artery disease (CAD) and ventricular dysfunction underwent rest ECG, DSE, and Tl-201 scintigraphy before revascularization, and a repeat rest 2-Dimensional (2-D) echocardiogram more than 3 mo later. Results: Total viability at baseline (% of total segments) was higher in the NoQ group by Tl-201 scintigraphy (87±19% versus 70±20%, p = 0.008) and by DSE (81±20% versus 65±24%, p = 0.013). As expected, the sensitivity of NoQ waves was low in predicting recovery of function (23%), and inferior to Tl-201 (82%) and DSE (84%) (p<0.05). However, specificity of NoQ waves for predicting recovery of global function was high (72%); higher than Tl-201 (50%) and DSE (45%). Positive predictive values were comparable among all modalities. Results were similar if the data were analyzed regionally for viability. Conclusion: Lack of pathologic Q waves is a specific and readily available marker of myocardial viability in patients with chronic CAD, which should alert the clinician for myocardial hibernation.

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

“…3,[8][9][10][11] Severe blockage of myocardial blood flow in a long time tends to cause myocardial necrosis while the lighter flow allows the myocardium last longer through the mechanism of myocardial hibernation though both can cause myocardial contractile dysfunction. 12,13 The contractile dysfunction can also occur despite reperfusion has been done with the flow of blood that has been normal or nearly normal in the condition of myocardial stunning.…”

“…9 Subjects with pathological Q waves have a lower myocardial viability than subjects without pathological Q waves on an assessment using the dobutamine stress echocardiography (DSE). 3 Study conducted by…”

“…2 Myocardial viability is lower in QMI. 3,4 Mortality and the incidence of congestive heart failure and cardiogenic shock are higher in QMI. [5][6][7] Pathological Q wave in the AMI is an abnormal negative deflection in electrocardiogram (ECG) which indicates a significant cardiac electrical abnormality.…”

“…1,8,9 The conditions that responsible in the formation of pathological Q wave are myocardial necrosis, hibernation, and stunning, those are known as the causes of ventricular contractile dysfunction. 3,[8][9][10][11] Left ventricular ejection fraction (LVEF) is an indicator of ventricular function that can be used to assess ventricular systolic function in AMI patients. Left ventricular systolic function can be measured non-invasively using echocardiography as LVEF.…”

Συσχέτιση Στηθάγχης Και Βιωσιμότητος Του Μυοκαρδίου

“…Απουσία Q κύματος ουλής -ύπαρξη κομβίωσης (notching) Σύμφωνα τους Joen HK και συν [155] του η απουσία κυμάτων Q σε ασθενείς με ισχαιμική μυοκαρδιοπάθεια αποτελεί ένδειξη μυοκαρδιακής βιωσιμότητας. Βέβαια, συγκρινόμενη με τις σπινθηρογραφικές και ηχωκαρδιογραφικές τεχνικές, είναι λιγότερο ευαίσθητη, αφού υπάρχουν πολλοί ασθενείς με Q έπαρμα που διαθέτουν βιώσιμο μυοκάρδιο.…”