Approach to a patient with QRS complex abnormality in ECG
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The document is a comprehensive overview of ECG interpretation focusing on QRS complex abnormalities, with case studies of patients presenting various symptoms and ECG findings, such as ventricular tachycardia and junctional tachycardia. It discusses the significance of QRS width and morphology to determine the origin of arrhythmias, as well as associated conditions like pericardial effusion and left ventricular hypertrophy. Key points include differentiating between narrow and broad QRS complexes, recognizing patterns associated with specific cardiac conditions, and the importance of identifying potentially life-threatening arrhythmias.
Approach to a patient with QRS complex abnormality in ECG
- 1. Fundamentals of ECG Approach to a patient with QRS complex abnormalities Dr. Md.Toufiqur Rahman MBBS, FCPS, MD, FACC, FESC, FRCP, FSCAI, FCCP,FAPSC, FAPSIC, FAHA,FACP Professor & head of Cardiology CMMC, Manikganj Ex professor of cardiology, NICVD, Dhaka
- 2. drtoufiq1971@gmail.comProfessor Dr Md Toufiqur Rahman Fundamentals of ECG QRS Complex
- 3. Fundamentals of ECG Conduction system of the heart
- 4. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Case-1: A 23 years old medical student presented with occasional palpitation, shortness of breath and chest discomfort. He had the following ECG. Figure: Sinus rhythm: Each narrow QRS complex is preceded by a normal P wave.
- 5. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG A 53 years old gentleman presented with palpitations for last 5 hours. He is smoker, diabetic, dyslipidemic and hypertensive. He had exertional chest discomfort for last 5 years and did coronary angiogram 3 years back and CAG revealed TVD and advised for revascularization. But he refused and was irregular in medication and reluctant for life style modification. He came to emergency department with this ECG. Figure: Junctional tachycardia: Narrow QRS complexes with no visible P waves.
- 6. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG A 44 years old gentleman presented with chest pain and excessive sweating for 45 minutes. He is diabetic, normotensive, smoker. His BP was 80/70 mm Hg. On he emergency department he has the following ECG. Figure: Ventricular tachycardia: Broad QRS complexes with no visible P waves. (Monomorphic VT)
- 7. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Right bundle branch block produces an RSR’ pattern in V1 and deep slurred S waves in the lateral leads. Left bundle branch block produces a dominant S wave in V1 with broad, notched R waves and absent Q waves in the lateral leads. Hyperkalaemia is associated with a range of abnormalities including peaked T waves Tricyclic poisoning is associated with sinus tachycardia and tall R’ wave in aVR Wolff-Parkinson White syndrome is characterised by a short PR interval and delta waves Ventricular pacing will usually have visible pacing spikes Hypothermia is associated with bradycardia, long QT, Osborn waves and shivering artefact How broad QRS can be identified by pattern recognition?
- 8. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Case-4: A 42 years old lady presented with palpitations and chest discomfort and came to Emergency department with the following ECG. Figure: Atrial flutter: Narrow QRS complexes are associated with regular flutter waves.
- 9. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Case-5: A 15 years old boy presented with palpitations and shortness of breath on exertion for last 2 years. He had the following ECG and on color Doppler echocardiogram revealed mitral valve prolapse with mitral regurgitation grade1+. He had no history of rheumatic fever. Figure: ECG showing both narrow and broad complexes (ventricular bigeminy)
- 10. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Ventricular Quadrigeminy
- 11. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Figure: ECG showing Couplets
- 12. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Figure: ECG of Non sustained VT Definitions vary regarding 3 or more PVCs. Some authors define three PVCs as a triplet of PVCs; whilst others describe this as a ‘short burst of VT’; but more commonly as NSVT A consensus definition would be: 3-30 consecutive PVCs with a rate >100bpm described as non-sustained VT (ventricular rhythm if rate <100bpm)
- 13. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Figure: ECG of a Supraventricular Bigeminy lead 2
- 14. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Case-6: A 21 years old gentleman presented with palpitations and shortness of breath on exertion for last 5 months. His pulse 104/min, low volume and auscultation examination revealed ejection systolic murmur over the whole precordium. His echocardiogram report revealed Severe aortic stenosis due to Bicuspid aortic valve with concentric Left ventricular Hypertrophy. He had the following ECG. Figure: ECG showing Left ventricular hypertrophy with repolarization abnormality
- 15. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Case-7: A 25 years old obese lady presented with chest discomfort for last 3 months. She had the following ECG. Figure: ECG showing low voltage
- 16. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG The most important cause is massive pericardial effusion, which produces a triad of: o Low voltage o Tachycardia o Electrical alternans Patients with this triad need to be immediately assessed for clinical or echocardiographic evidence of tamponade. Other causes of low voltage include: Fluid: Pericardial effusion; Pleural effusion Fat: Obesity Air: Emphysema; Pneumothorax Infiltrative / Connective Tissue Disorders Myxoedema Infiltrative myocardial diseases — i.e. restrictive cardiomyopathy due to amyloidosis, sarcoidosis, haemochromatosis Constrictive pericarditis Scleroderma Loss of viable myocardium: Previous massive MI; End-stage dilated cardiomyopathy What are the causes of low voltage ECG?
- 17. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Fundamentals of ECG Case 8: A 54 years old lady presented with chest heaviness with low grade fever and palpitations for last 40 days. She has diabetes for last 15 years , now uncontrolled. She had the following ECG and her echocardiogram report showed massive pericardial effusion. Figure: Electrical alternans
- 18. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Main Features to Consider • Width of the complexes: Narrow versus broad. • Voltage (height) of the complexes. • Spot diagnoses: Specific morphology patterns that are important to recognise. Fundamentals of ECG
- 19. drtoufiq1971@gmail.com QRS Complex naming convention Professor Dr Md Toufiqur Rahman Fundamentals of ECG
- 20. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman QRS Width Normal QRS width is 70-100 ms (a duration of 110 ms is sometimes observed in healthy subjects). The QRS width is useful in determining the origin of each QRS complex (e.g. sinus, atrial, junctional or ventricular). Narrow complexes (QRS < 100 ms) are supraventricular in origin. Broad complexes (QRS > 100 ms) may be either ventricular in origin, or due to aberrant conduction of supraventricular complexes (e.g. due to bundle branch block, hyperkalaemia or sodium-channel blockade). Fundamentals of ECG
- 21. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman ECG showing both narrow and broad complexes Sinus rhythm with frequent ventricular ectopic beats (VEBs) in a pattern of ventricular bigeminy. The narrow beats are sinus in origin, the broad complexes are ventricular. Fundamentals of ECG
- 22. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Narrow QRS Complex Morphology Narrow (supraventricular) complexes arise from three main places: Sino-atrial node (= normal P wave) Atria (= abnormal P wave / flutter wave / fibrillatory wave) AV node / junction (= either no P wave or an abnormal P wave with a PR interval < 120 ms) Fundamentals of ECG
- 23. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Sinus rhythm: Each narrow complex is preceded by a normal P wave. Atrial flutter: Narrow QRS complexes are associated with regular flutter waves. Fundamentals of ECG
- 24. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Junctional tachycardia: Narrow QRS complexes with no visible P waves. Fundamentals of ECG
- 25. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Broad/Wide QRS Complexes • A QRS duration > 100 ms is abnormal • A QRS duration > 120 ms is required for the diagnosis of bundle branch block or ventricular rhythm • Broad complexes may be ventricular in origin or due to aberrant conduction secondary to: 1. Bundle branch block (RBBB or LBBB) 2. Hyperkalaemia 3. Poisoning with sodium-channel blocking agents (e.g. tricyclic antidepressants) 4. Pre-excitation (i.e. Wolff-Parkinson-White syndrome) 5. Ventricular pacing 6. Hypothermia 7. Intermittent aberrancy (e.g. rate-related aberrancy) Fundamentals of ECG
- 26. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Ventricular tachycardia: Broad QRS complexes with no visible P waves. Fundamentals of ECG
- 27. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Ventricular vs supraventricular rhythms • Differentiation between ventricular complexes and aberrantly conducted supraventricular complexes may be difficult. • In general, aberrant conduction of sinus rhythm and atrial rhythms (tachycardia, flutter, fibrillation) can usually be identified by the presence of preceding atrial activity (P waves, flutter waves, fibrillatory waves). • However, aberrantly conducted junctional (AV nodal) complexes may appear identical to ventricular complexes as both produce broad QRS without any preceding atrial activity. Fundamentals of ECG
- 28. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Ventricular vs supraventricular rhythms • In the case of ectopic beats, this distinction is not really important (as occasional ectopic beats do not usually require treatment). • However, in the case of sustained tachyarrhythmias, the distinction between ventricular tachycardia and SVT with aberrancy becomes more important. Fundamentals of ECG
- 29. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman many causes of broad QRS can be identified by pattern recognition: Right bundle branch block produces an RSR’ pattern in V1 and deep slurred S waves in the lateral leads. Left bundle branch block produces a dominant S wave in V1 with broad, notched R waves and absent Q waves in the lateral leads. Hyperkalaemia is associated with a range of abnormalities including peaked T waves Fundamentals of ECG
- 30. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman many causes of broad QRS can be identified by pattern recognition: Tricyclic poisoning is associated with sinus tachycardia and tall R’ wave in aVR Wolff-Parkinson White syndrome is characterised by a short PR interval and delta waves Ventricular pacing will usually have visible pacing spikes Hypothermia is associated with bradycardia, long QT, Osborn waves and shivering artefact Fundamentals of ECG
- 31. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman High Voltage QRS Morphology Increased QRS voltage is often taken to infer the presence of left ventricular hypertrophy. However, high left ventricular voltage (HLVV) may be a normal finding in patients less than 40-45 years of age, particularly slim or athletic individuals. There are multiple “voltage criteria” for left ventricular hypertrophy. Probably the most commonly used are the Sokolov-Lyon criteria (S wave depth in V1 + tallest R wave height in V5-V6 > 35 mm). Voltage criteria must be accompanied by non-voltage criteria to be considered diagnostic of left ventricular hypertrophy. Fundamentals of ECG
- 32. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Low Voltage QRS Morphology The QRS is said to be low voltage when: The amplitudes of all the QRS complexes in the limb leads are < 5 mm; or The amplitudes of all the QRS complexes in the precordial leads are < 10 mm Fundamentals of ECG
- 33. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Electrical Alternans This is when the QRS complexes alternate in height. The most important cause is massive pericardial effusion, in which the alternating QRS voltage is due to the heart swinging back and forth within a large fluid-filled pericardium. Fundamentals of ECG
- 34. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Electrical Alternans This is when the QRS complexes alternate in height. The most important cause is massive pericardial effusion, in which the alternating QRS voltage is due to the heart swinging back and forth within a large fluid-filled pericardium. Fundamentals of ECG
- 35. drtoufiq1971@gmail.com QRS Complex Professor Dr Md Toufiqur Rahman Spot Diagnoses These cardiac diseases produce distinctive QRS morphologies that are important not to miss: Brugada syndrome (partial RBBB with ST elevation in V1-2) Wolff-Parkinson White Syndrome (delta wave) Tricyclic poisoning (wide QRS with dominant R wave in aVR) Fundamentals of ECG