Electrocardiography (ECG) EKG ASSISTANCE PROF.DR GHAZI HAJI CARDIOLOGIST

Paper Connection Rate(calculation)tachycardia (sinus Paper Connection Rate(calculation)tachycardia (sinus.SVT)Bradycardia Rhythm (sinus ,atrial fibrillation,ectopic) Axis's Ischemia (STEMI,NSTEMI) Arrhythmias( venticular tachycardia ,v fibrillation) Heart block(atrioventricular block PR interval .BBB) Electrolyte ( prolong QT interval) Left ventricular hypertrophy Right ventricular hypertrophy

Heart rate Our first method is simple. Count the number of QRS complexes over a 6 second interval. Multiple by 10 to determine heart rate. This method works well for both regular and irregular rhythms.. The second method uses small boxes. Count the number of small boxes for a typical R-R interval. Divide this number into 1500 to determine heart rate.. 

HR= 60-90BP Normal sinus rhythm sinus tachycardia sinus bradycardia

Sinus Tachycardia

Sinus bradycardia

Are they regular, meaning that each heart beat's R-R interval is equal Are they regular, meaning that each heart beat's R-R interval is equal? Small variations of up to 10% are considered equal. Is the rhythm regularly irregular? Is the rhythm irregularly irregular?

Ventricular ectopic

Normal Axis = QRS axis between -30 and +90 degrees Normal Axis = QRS axis between -30 and +90 degrees. Left Axis Deviation = QRS axis less than -30 degrees. Right Axis Deviation = QRS axis greater than +90 degrees. Extreme Axis Deviation = QRS axis between -90 and 180 degrees (AKA “Northwest Axis”).

Positive Positive Left lower quadrant Normal (0 to +90 LEAD (I) LEAD AVF QUADRANT AXIS Positive Positive Left lower quadrant Normal (0 to +90 Positive Negative Left upper quadrant Possible LAD (0 to -90 Negative Positive Right lower quadrant RAD (+90 to 180 Negative Negative Right upper quadrant Extreme Axis Deviation (-90 to 180 degrees)

NORMAL AXIS

Left axis

Right axis

P wave . The amplitude is normally 0.05 to 0.25mV (0.5 to 2.5 small boxes). Normal duration is 0.06-0.11 seconds (1.5 to 2.75 small boxes). P-wave questions: Are they present? Do they occur regularly? Is there one P-wave for each QRS complex? Are the P-Waves smooth, rounded, and upright? Do all P-Waves have similar shapes?  

No clear p wave

The PR Interval indicates AV conduction time The PR Interval indicates AV conduction time. Normally this interval is 0.12 to 0.20 seconds (3 to 5 small boxes) in adults, longer in elderly people Short PR? Wolff parkinson syndrom Long PR .? Heart block .Is the PR-Interval constant across the ECG tracing?

The QRS complex indicates ventricular depolarization The QRS complex indicates ventricular depolarization. Use calipers, marking paper or by counting small boxes. Normally this interval is 0.06 to 0.12 seconds (1.5 to 3 boxes).  QRS questions: Does the QRS interval -Wide or narrow? Does the QRS ,High or low voltage?(right ventricular hypertrophy ,left ventricular hypertrophy) Are the QRS complexes similar in appearance across the ECG tracing? ectopics  

Low voltage

High voltage

Wide QRS Narrow QRS

The ST segment represents the early part of ventricular repolarization The ST segment represents the early part of ventricular repolarization. The ST segment is the line that from the end of the QRS complex to beginning of the T wave. Normally the ST segment is flat, being neither positive or negative relative to the baseline. 

Anterior -STEMI

The T wave indicates the repolarization of the ventricules The T wave indicates the repolarization of the ventricules. It is a slightly asymmetrical waveform which follows , the QRS complex. Either positive (up) or negative (down)?  

The QT interval represents the time of ventricular activity including both depolarization and repolarization . It is measured from the beginning of the QRS complex to the end of the T wave. Normally, the QT interval is 0.36 to 0.44 seconds (9-11 boxes). The QT interval will vary with patient gender, age and heart rate.  

Ventricular tachycardia

Ventricular fibrillation

Supraventricular tachycardia

Pause