Exercise induced St elevation in pt of cardiac disease .
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Exercise –induced ST Elevation
Dr sajeer K T
Senior Resident, Dept. of Cardiology
Medical College, Calicut
ST Elevation in leads with out Q waves
ST Elevation in leads with Q waves
ST Elevation at Rest (Early Repolarization)
ST Elevation in aVR
ST Elevation in leads with out Q waves
-high-grade proximal LAD stenosis
-high-grade stenosis of a large right coronary artery
-severe coronary spasm –Prinzmetal’s angina
-commonly at rest
-occasionally occurs with exercise
STE During TMT indicates hemodynmically significant coronary
atheroma
Take-home message
ST elevation in V2,V3,V4 = severe anterior wall ischemia
-high grade stenosis of LAD
ST elevation in II,III aVF= severe inferior wall ischemia
-high grade stenosis of RCA
ST Elevation in leads with Q waves
-Originally believed to be ventricular akinetic or dyskinetic
myocardial segment.
Recently been shown to (with the help of thallium scintigram)
indicate peri-infarction ischemia
Richard F Dunn, et al. Circulation Vol61, No 5, May 1980
Exercise-induced ST E in leads without Q waves on the
resting ECG is associated with severe myocardial ischemia.
Exercise induced STE over Q waves after MI has been related to
-Peri-infarctionalischemia
-Abnormal left ventricular wall motion
-LV aneurysm.
ST Elevationat rest (Early Repolarization)
Commonly seen in young black men
Common in well conditioned athletes
26% of the affected patients have eventual
disappearance of the ECG findings as they get older
Subjects with normal hearts show a degree of STE in
anterior precordial leads and also frontal leads
ST Elevationat rest (Early Repolarization)
STE returns to normal during exercise.
Usually associated with normal heart.
ST Elevation in aVR
-Interpretation of ST segment changes in this lead has been
ignored for decades.
-Lead aVR : referred as “no man’s land” or “the orphan lead”
-Directed downward and into the left ventricular cavity from above
-Thought to reflect basal interventricular septal ischemia
-Obtain information on the electrical changes as viewed from
the upper right side of the heart to include the RVOT and IVS
-The site of ST-segment depression in ECG does not typically
correlate with the ischemic territory
-Many clinicians believe that they represent reciprocal
changes from leads aVL, II, V5, and V6.
Lead aVR
ACC/AHA 2002 exercise stress test guidelines did not support a
major role for lead aVR
Lead aVR and Exercise Stress Testing
STE in lead aVR is not an uncommon finding on exercise treadmill
tests, with a reported incidence of 10% to 25%
Role of ST elevation In aVR in Acute Coronary
syndrome
Presence of STE in lead aVR greater than STE in lead V1
-81% sensitive
-80% specific
-81% overall accuracy
for the prediction of acute LMCA obstruction
Harbinger of poor prognosis in the setting of acute MI
Yamaji H et al. Prediction of acute left main coronary artery obstruction by 12-lead
electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in
lead V1. J Am CollCardiol2001;38:1348 –54.
Exercise–induced ST-segment elevation in ECG lead aVR is a useful
indicator of significant left main or ostial LAD coronary artery
stenosis.
UthamalingamS, et al. J Am CollCardiolImg2011;4:176–86.
BACKGROUND:
Although STE in lead aVR is an indicator of LMCA or very proximal
LAD occlusion in acute coronary syndromes, its predictive power in
the setting of ETT is uncertain.
Hypothesis :
Exercise treadmill testing (ETT)–induced ST-segment elevation
(STE) in ECG lead aVR is an important indicator of significant left
main coronary artery (LMCA) or ostial left anterior descending
coronary artery (LAD) stenosis.
454 patients
LMCA
( n= 38)
Ostial LAD
(n=42)
CAD with out LMCA
or Ostial LAD
stenosis(n=276)
No CAD
(n=103)
Exclusion criteria :
-ACS or prior CABG
-Who had undergone pharmacological stress in conjunction with MPI
-LBBB, LVH with marked strain pattern ( DS STD 1 mm with biphasic or inverted
T waves), or marked anterior T-wave inversions (the Wellenspattern)
-Leads V1 to V3 were not used for ischemia assessment in patients with RBBB
Database of patients undergone cardiac catherization from jan
2008-jul 2009
All patients had undergone ETT according to the standard Bruce protocol with
(n= 378) or without (n = 76) myocardial perfusion imaging (MPI; rest/stress
99mTc-methoxyisobutylisonitrile [MIBI]) ≤6 months before the clinically
indicated cardiac catheterization.
At pre-test probability of 17%(incidence of LMCA or ostial LAD in the study
population), the post-test probability was increased almost 3-fold to 45%with
1-mm horizontal STE in lead aVR.
The green line indicates post-test outcome on the basis of chance alone and
demonstrates no change from the pre-test probability of disease.
Bayesian Analysis of STE in Lead aVR for the Prediction
LMCA or Ostial LAD Stenosis
STE in lead aVRhave Sensitivity, specificity, and overall predictive
accuracy approximately 75% to 80% for detecting LMCA or ostial
LAD disease
High negative predictive accuracy (94%).
Only modest positive predictive accuracy (44%).
Bayesian analysis of the data demonstrated that:
1-mm horizontal STE in lead aVR almost tripled the
post-test odds of finding of significant LMCA or ostial LAD
stenosis, and so should not be ignored in the interpretation of
obtained with ETT (Bruce protocol).
STE in lead aVR is the best predictor of left main stenosis after
multivariate analysis
Percentage of patients with 1-mm STE in lead aVR during
ETT
17% (1VD), 27% (2VD), and 39% (3VD) without LMCA or ostial
LAD stenosis
8% without significant CAD
76% of patients with LMCA or ostial LAD stenosis.
This iJACCstudy suggests:
ST-segment elevation during exercise testing
has moved beyond being ignored as unimportant
and should generate a high level of suspicion for
the presence of significant coronary disease.
Lead aVR: Dead or Simply Forgotten?
The only truly dead are those who have been
forgotten.
—Jewish proverb