B P3 C14 ECG Flashcards
Pulmonary embolism causing acute RV pressure overload may generate characteristic ECG patterns including:
QR or qR pattern in the right sided leads
S1Q3T3 pattern
ST-segment deviation and T wave inversions in leads V1 to V3
Incomplete or complete RBBB.
Left Anterior Fascicular Block
Frontal plane mean QRS axis between −45 and −90 degrees
qR pattern in lead aVL
QRS duration <120 msec
Time to peak R wave in aVL ≥ 45 msec
Left Posterior Fascicular Block
Frontal plane mean QRS axis >90 degrees (or >110–120 degrees)
rS pattern in leads I and aVL with qR patterns in leads III and aVF
QRS duration <120 msec
Exclusion of other factors causing right axis deviation
CLBBB
- QRS duration ≥120 msec
- Broad, notched, or slurred R waves in leads I, aVL, V5, and V6
- Small or absent initial r waves in leads V1 and V2 followed by deep S waves
- Absent septal q waves in leads I, V5, and V6
- Prolonged time to peak R wave (>60 msec) in V5 and V6
CRBBB
QRS duration ≥120 msec
rsr′, rsR′, or rSR′, patterns in leads V1 and V2
S waves in leads I and V6 ≥40 msec wide
Normal time to peak R wave in leads V5 and V6 but >50 msec in V1
Most common pattern of bifascicular block
RBBB + LAFB
Conduction delay in the RBB plus delay in either the main LBB or in both the left anterior and the left posterior fascicle
Trifascicular block
ECG pattern of trifascicular block
Bifascicular block + evidence of prolonged conduction below the AV node
Occasionally the ECG in acute coronary syndromes involving the occlusion of the left anterior descending (LAD) coronary will show a paradoxical combination of ST depressions and prominent T waves, especially in the precordial leads, sometimes now referred to as _____
DeWinter’s sign
Necrosis of sufficient myocardial tissue can lead to _____ as a result of loss of electromotive forces in the infarcted area
Decreased R wave amplitude
or
Frank Q waves (typically >30 to 40 msec in duration in multiple leads)
Earliest ECG manifestations of STEMI.
Ischemic ST-segment elevation and hyperacute T wave changes
This development usually reflects spontaneous recanalization or good collateral circulation and is a positive prognostic sign.
Complete normalization of the ECG after Q wave infarction
Correlate strongly with severe underlying wall motion disorders (akinetic or dyskinetic zone), although not necessarily a frank ventricular aneurysm.
Persistent Q waves and ST- segment elevation seen several weeks or more after infarction
The presence of an _____ or similar type of multiphasic complex in the mid-left chest leads or lead I is another reported marker of an LV aneurysm
rSr′ pattern
Classic ECG marker of Prinzmetal’s variant (vasospastic) angina
Transient ST-segment elevation
ECG sign/patter in some patients with ischemic chest pain exhibit deep coronary T wave inversions in multiple precordial leads (e.g.,V1 through V4, I, and aVL), with or without cardiac biomarker level elevations.
LAD–T wave or Wellens’ pattern
Exercise-induced transient inversion of precordial U waves has been correlated with severe stenosis of the _____ coronary artery
LAD
_____ U waves are uncommon and are strongly associated with adverse cardiac events.
Negative U waves
Diagnostic criteria for early repolarization
(1) Prominent notch or J wave at the end of QRS complex or slur on the downstroke of the R wave
(2) Peak of the notch or J wave is 0.1 mV or greater in amplitude in two or more contiguous leads, excluding V1 to V3 (to avoid cases of Brugada pattern)
(3) QRS duration is normal