Myocardial Ischemia and Infarction Flashcards
Which is the characteristic feature of anterior wall Q wave infarction ?
Loss of normal R wave progression in at least two or three of the chest leads.
Features of anteroseptal infarctions ?
Disappearance of r waves in leads V1 to V3 and appearance of an entirely negative (QS) complex.
Features of anterior free wall/ antero-apical infarctions ?
Appearance of abnormal Q waves as part of QS or QR complexes in leads V3 to V6.
Persistent ST segment elevations months to years after an MI (especially anterior) may represent ?
A ventricular aneurysm.
When is a Q wave generally considered abnormal ?
When its duration is 0.04 sec or more in lead I, all three inferior lead, or leads V3 to V6.
Most common ECG change with predominant subendocardial ischemia ?
ST segment depression with a characteristic squared-off or downsloping shape.
Which ST segment changes are considered normal as a test response ?
ST depressions of less than 1 mm (or depressions of only the J point) with a rapid upward sloping of the ST segment.
Prinzmetal’s Angina is associated with ?
Transient ST elevations
Which findings are termed nonspecific ST-T changes ?
Slight T wave flattening or minimal T wave inversions.
Two important and common factors of ST depressions?
Digitalis effect and hypokalemia.
Define Wellen’s syndrome (typically caused by a tight stenosis in the proximal LAD coronary artery system.
Deep T wave inversions in multiple precordial leads (e.g. V1 or V2 to V4 or V5) with or without cardiac enzyme elevations and with minimal or no ST elevations.
ECG changes in patients with cerebrovascular accident, particularly subarachnoid hemorrhage ?
Very deep, widely splayed T wave inversions with a long QT interval and sometimes prominent U waves.
