ECG- ST segment
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This document contains a lecture on ST segment abnormalities from Professor Dr. Md Toufiqur Rahman. It discusses the normal ST segment and various causes of ST elevation and depression. ST segment abnormalities most commonly indicate myocardial ischemia or infarction. Other causes of ST elevation discussed include pericarditis, early repolarization, left bundle branch block, left ventricular hypertrophy, ventricular aneurysm, Brugada syndrome, ventricular pacing, and raised intracranial pressure. The lecture includes examples and descriptions of ST segment changes in each condition.
ECG- ST segment
- 1. MBBS, FCPS, MD, FACC, FESC, FRCP, FSCAI, FCCP,FAPSC, FAPSIC, FAHA,FACP,FASE Professor and Head of Cardiology Colonel Malek Medical College , Manikganj. For under-graduates drtoufiq19711@yahoo.com20/11/2019 Under graduate version 2019
- 2. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman • The ST segment is the flat, isoelectric section of the ECG between the end of the S wave (the J point) and the beginning of the T wave. • The ST Segment represents the interval between ventricular depolarization and repolarization. • The most important cause of ST segment abnormality (elevation or depression) is myocardial ischaemia or infarction.
- 3. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman
- 4. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Causes of ST Segment Elevation • Acute myocardial infarction • Coronary vasospasm (Printzmetal’s angina) • Pericarditis • Benign early repolarization • Left bundle branch block • Left ventricular hypertrophy • Ventricular aneurysm • Brugada syndrome • Ventricular paced rhythm • Raised intracranial pressure • Takotsubo Cardiomyopathy
- 5. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of the Elevated ST segment Myocardial Infarction Acute STEMI may produce ST elevation with either concave, convex or obliquely straight morphology.
- 6. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of the Elevated ST segment
- 7. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of the Elevated ST segment
- 8. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Morphology of the Elevated ST segment Patterns of ST Elevation Acute ST elevation myocardial infarction (STEMI) ST segment elevation and Q-wave formation in contiguous leads. • Septal (V1-2) • Anterior (V3-4) • Lateral (I + aVL, V5-6) • Inferior (II, III, aVF) • Right ventricular (V1, V4R) • Posterior (V7-9)
- 9. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Morphology of the Elevated ST segment Acute ST elevation myocardial infarction (STEMI) There is usually reciprocal ST depression in the electrically opposite leads. For example, STE in the high lateral leads I + aVL typically produces reciprocal ST depression in lead III
- 10. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Coronary Vasospasm (Prinzmetal’s angina) • This causes a pattern of ST elevation that is very similar to acute STEMI — i.e. localised ST elevation with reciprocal ST depression occurring during episodes of chest pain. • However, unlike acute STEMI the ECG changes are transient, reversible with vasodilators and not usually associated with myocardial necrosis. • It may be impossible to differentiate these two conditions based on the ECG alone.
- 11. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Pericarditis • Acute Pericarditis causes widespread concave (“saddleback”) ST segment elevation with PR segment depression in multiple leads, typically involving I, II, III, aVF, aVL, and V2-6. • Spodick’s sign was first described by David H. Spodick in 1974 as a downward sloping TP segment with specificity for acute pericarditis.
- 12. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Pericarditis Concave “saddleback” ST elevation in leads I, II, III, aVF, V5-6 with depressed PR segments. There is reciprocal ST depression and PR elevation in leads aVR and V1.
- 13. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Benign Early Repolarization • Benign Early Repolarization (BER) causes mild ST elevation with tall T-waves mainly in the precordial leads. • BER is a normal variant commonly seen in young, healthy patients. • There is often notching of the J-point — the “fish- hook” pattern. • The ST changes may be more prominent at slower heart rates and disappear in the presence of tachycardia.
- 14. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 8 ST segment Professor Dr Md Toufiqur Rahman Benign Early Repolarization There is slight concave ST elevation in the precordial and inferior leads with notching of the J-point (the “fish-hook” pattern)
- 15. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Left Bundle Branch Block (LBBB) • In Left bundle branch block (LBBB), the ST segments and T waves show “appropriate discordance” — i.e. they are directed opposite to the main vector of the QRS complex. • This produces ST elevation and upright T waves in leads with a negative QRS complex (dominant S wave), while producing ST depression and T wave inversion in leads with a positive QRS complex (dominant R wave).
- 16. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Left Bundle Branch Block (LBBB) ST elevation in leads with deep S waves — most apparent in V1-3. ST depression in leads with tall R waves — most apparent in I and aVL.
- 17. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Left Ventricular Hypertrophy (LVH) Left Ventricular Hypertrophy (LVH) causes a similar pattern of repolarization abnormalities as LBBB, with ST elevation in the leads with deep S-waves (usually V1-3) and ST depression/T-wave inversion in the leads with tall R waves (I, aVL, V5-6).
- 18. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Left Ventricular Hypertrophy (LVH) • Deep S waves with ST elevation in V1-3 • ST depression and T-wave inversion in the lateral leads V5-6 • there is also right axis deviation, which is unusual for LVH and may be due to associated left posterior fascicular block
- 19. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Ventricular Aneurysm • Ventricular Aneurysm – residual ST elevation and deep Q waves seen in patients with previous myocardial infarction. • It is associated with extensive myocardial damage and paradoxical movement of the left ventricular wall during systole.
- 20. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Ventricular Aneurysm • ST elevation with deep Q waves and inverted T waves in V1-3. • This pattern suggests the presence of a left ventricular aneurysm due to a prior anteroseptal MI.
- 21. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Brugada Syndrome • Brugada Syndrome is an inherited channelopathy (a disease of myocardial sodium channels) that leads to paroxysmal ventricular arrhythmias and sudden cardiac death in young patients. • The tell-tale sign on the resting ECG is the “Brugada sign” — ST elevation and partial RBBB in V1-2 with a “coved” morphology.
- 22. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Brugada Syndrome • ST elevation and partial RBBB in V1-2 with a coved morphology — the “Brugada sign”.
- 23. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Ventricular Paced Rhythm Ventricular pacing (with a pacing wire in the right ventricle) causes ST segment abnormalities identical to that seen in LBBB. There is appropriate discordance, with the ST segment and T wave directed opposite to the main vector of the QRS complex.
- 24. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Ventricular Paced Rhythm There is appropriate discordance, with the ST segment and T wave directed opposite to the main vector of the QRS complex.
- 25. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Raised Intracranial Pressure • Raised Intracranial Pressure (ICP) (e.g. due to intracranial haemorrhage, traumatic brain injury) may cause ST elevation or depression that simulates myocardial ischaemia or pericarditis. • More commonly, raised ICP is associated with widespread, deep T-wave inversions (“cerebral T waves“).
- 26. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Raised Intracranial Pressure Widespread ST elevation with concave (pericarditis-like) morphology in a patient with severe traumatic brain injury
- 27. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Takotsubo Cardiomyopathy • Takotsubo Cardiomyopathy, A STEMI mimic producing ischaemic chest pain, ECG changes +/- elevated cardiac enzymes with characteristic regional wall motion abnormalities on echocardiography. • Typically occurs in the context of severe emotional distress (“broken heart syndrome“). Commonly associated with new ECG changes (ST elevation or T wave inversion) or moderate troponin rise.
- 28. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Takotsubo Cardiomyopathy
- 29. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Less Common Causes of ST segment Elevation • Pulmonary embolism and acute cor pulmonale (usually in lead III) • Acute aortic dissection (classically causes inferior STEMI due to RCA dissection) • Hyperkalaemia • Sodium-channel blocking drugs (secondary to QRS widening) • J-waves (hypothermia, hypercalcaemia) • Following electrical cardioversion • Others: Cardiac tumour, myocarditis, pancreas or gallbladder disease
- 30. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Transient ST elevation after DC cardioversion from VF
- 31. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman J waves in hypothermia simulating ST elevation
- 32. drtoufiq1971@gmail.com 21.11.2019 CMMC-02 ECG Lecture 07 ST segment Professor Dr Md Toufiqur Rahman Causes of ST Depression • Myocardial ischaemia / NSTEMI • Reciprocal change in STEMI Posterior MI • Digoxin effect • Hypokalaemia • Supraventricular tachycardia • Right bundle branch block • Right ventricular hypertrophy • Left bundle branch block • Left ventricular hypertrophy • Ventricular paced rhythm
- 33. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression • ST depression can be either upsloping, downsloping, or horizontal. • Horizontal or downsloping ST depression ≥ 0.5 mm at the J-point in ≥ 2 contiguous leads indicates myocardial ischaemia (according to the 2007 Task Force Criteria). • Upsloping ST depression in the precordial leads with prominent De Winter T waves is highly specific for occlusion of the LAD.
- 34. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression • Reciprocal change has a morphology that resembles “upside down” ST elevation and is seen in leads electrically opposite to the site of infarction. • Posterior MI manifests as horizontal ST depression in V1-3 and is associated with upright T waves and tall R waves.
- 35. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression
- 36. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression ST segment morphology in myocardial ischaemia
- 37. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression Reciprocal change
- 38. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression ST segment morphology in posterior MI
- 39. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression Myocardial Ischaemia • ST depression due to subendocardial ischaemia may be present in a variable number of leads and with variable morphology. • It is often most prominent in the left precordial leads V4-6 plus leads I, II and aVL. • Widespread ST depression with ST elevation in aVR is seen in left main coronary artery occlusion and severe triple vessel disease.
- 40. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression Myocardial Ischaemia ST depression localised to the inferior or high lateral leads is more likely to represent reciprocal change than subendocardial ischaemia
- 41. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression Reciprocal Change • ST elevation during acute STEMI is associated with simultaneous ST depression in the electrically opposite leads. • Inferior STEMI produces reciprocal ST depression in aVL (± lead I). • Lateral or anterolateral STEMI produces reciprocal ST depression in III and aVF (± lead II). • Reciprocal ST depression in V1-3 occurs with posterior infarction
- 42. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression Reciprocal Change Reciprocal ST depression in aVL with inferior STEMI
- 43. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Morphology of ST Depression Reciprocal Change Reciprocal ST depression in III and aVF with high lateral STEMI
- 44. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Posterior Myocardial Infarction Acute posterior STEMI causes ST depression in the anterior leads V1- 3, along with dominant R waves (“Q-wave equivalent”) and upright T waves. There is ST elevation in the posterior leads V7-9.
- 45. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman De Winter T Waves De Winter T waves: a pattern of up-sloping ST depression with symmetrically peaked T waves in the precordial leads is considered to be a STEMI equivalent, and is highly specific for an acute occlusion of the LAD.
- 46. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Digoxin Effect Digoxin Effect: Treatment with digoxin causes down sloping ST depression with a “sagging” morphology, reminiscent of Salvador Dali’s moustache.
- 47. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Hypokalaemia Hypokalaemia causes widespread downsloping ST depression with T-wave flattening/inversion, prominent U waves and a prolonged QU interval.
- 48. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Right ventricular hypertrophy (RVH) Right ventricular hypertrophy (RVH) causes ST depression and T-wave inversion in the right precordial leads V1-3.
- 49. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Right Bundle Branch Block (RBBB) Right Bundle Branch Block (RBBB) may produce a similar pattern of repolarisation abnormalities to RVH, with ST depression and T wave inversion in V1-3.
- 50. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Supraventricular tachycardia (SVT)
- 51. drtoufiq1971@gmail.com 28.11.2019 CMMC-02 ECG Lecture 08 ST segment Professor Dr Md Toufiqur Rahman Supraventricular tachycardia (SVT) Supraventricular tachycardia (e.g. AVNRT) typically causes widespread horizontal ST depression, most prominent in the left precordial leads (V4-6). This rate-related ST depression does not necessarily indicate the presence of myocardial ischaemia, provided that it resolves with treatment.