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 - 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 -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 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 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 Vol 61, 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 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-infarctional ischemia - Abnormal left ventricular wall motion - LV aneurysm. Exercise induced STE over Q waves after MI has been related to - Peri-infarctional ischemia - Abnormal left ventricular wall motion - LV aneurysm.

ST Elevation at rest (Early Repolarization) Commonly seen in young black men Common in well conditioned athletes 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 Elevation at rest (Early Repolarization) STE returns to normal during exercise. Usually associated with normal heart. 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. -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 - 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 - 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 -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. - 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 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 Coll Cardiol2001;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. Uthamalingam S, et al. J Am Coll Cardiol Img 2011;4:176–86. Exercise–induced ST-segment elevation in ECG lead aVR is a useful indicator of significant left main or ostial LAD coronary artery stenosis. Uthamalingam S, et al. J Am Coll Cardiol Img 2011;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 Wellens pattern) -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. 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 aVR have 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%). STE in lead aVR have 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). 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 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 iJACC study 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. This iJACC study 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