450 likes | 719 Views
ECG PRACTICAL APPROACH. Dr. Hossam Hassan Consultant Emergency Medicine. Objectives. To emphasize simplicities Practical approach Interpretation & clinical scenario are inseparable Systematic approach. Conduction System. Nomenclature. Magic numbers of Dr. Hossam. 3. 5. Rate
E N D
ECG PRACTICAL APPROACH Dr. Hossam Hassan Consultant Emergency Medicine
Objectives • To emphasize simplicities • Practical approach • Interpretation & clinical scenario are inseparable • Systematic approach
Rate Rhythm axis P-wave PR interval QRS complex ST segment T-wave Systematic approach 3 5
Rate • The interval between 2 successive R-wave • How many big squares? • Divide 300 / # big squares • Normal 60 – 100/min 5 3
Rhythm Sinus Rhythm Every P=wave is followed by QRS complex P-wave is upright in lead II
Types of Sinus Rhythm • NSR • Sinus Tachycardia • Sinus Bradycardia • Sinus arrhythmia
Axis • Normal axis • Right axis deviation • Left axis deviation
P-wave • Atrial depolarization • Atrial contraction is a result • Normally a dome-like structure
Abnormalities of P-wave • Peaked p-pulmonle • Pulmonary HTN • PE • Pulmonary valve stenosis • M-shaped M-mitrale • Mitral valve stenosis • Left atrial hypertrophy • Inverted 2nd atrial / junctional ectopy
PR interval • Definition From the start of P to beginning of QRS • Represent the delay in transmission in AV node • Normally 0.12 – 0.20 msec 3 5
Abnormalities of PR interval 5 • Prolonged > 1st degree HB • Short < Pre-excitation syndromes • WPW Syndrome • LGL Syndrome Junctional rhythm 3
QRS Complex • Amplitute • Duration • Shape • Q-wave • R-wave 5
QRS AMPLITUTE • LVH By voltage criteria • S-wave in V 1 or V 2 + R-wave in V5 or V6 35
Causes of LVH • HTN • Aortic stenosis • HOCM • Aortic regurgitation • Mitral regurgitation
QRS DURATION • Ventricular depolarization • Ventricular contraction is a result • Normally < 0.12 msec < small squares 3
Causes of wide QRS • Ventricular tachycardia • BBB • Left BBB • Right BBB
Shape • Upstroke & downstroke of R-wave • Delta wave
Q-wave • 1st negative deflection after the P-wave • Normally 1mm wide & 2 mm deep • Lead III , V5 & V6 Pathological Q-wave Wider & deeper >1/4 of the ensuing R-wave Old MI
Causes +ve R-wave in V I • RVH • R BBB • Posterior MI • Type A WPW
ST-Segment • From the end of S-wave to the beginning of T-wave • Normally iso-electric • Abnormalities • Elevated • depressed
Elevated ST segment • Acute MI • Pericarditis • Early repolarization pattern in the young
Infarct localization • Inferior • Lead II , III , aVF • Septal • V I , V II • Anterior • V3 , V4
Lateral • Lead I , AVL,V5 , V6 • Posterior MI - Prominent R wave in V1,V2 with depressed ST segment
Depressed ST Segment • Unstable angina • Left ventricular strain pattern
T-wave • Ventricular repolarization • Dome like structure • Abnormalities • Peaked / tented t-wave • Hyperkalaemia • Subendocadial ischemia • Inverted • LV Strain pattern • Dynamic t-wave changes of ischemia