Skip to main content

Posts

Showing posts with the label ECG

ECG 3-Normal Sinus Rhythm (NSR)

•    Etiology: the electrical impulse is formed in the SA node and conducted normally. •    This is the normal rhythm of the heart; other rhythms that do not conduct via the typical pathway are called arrhythmias. NSR Parameters •    Rate                60 - 100 bpm      •    Regularity            regular •    P waves            normal •    PR interval            0.12 - 0.20 s •    QRS duration        0.04 - 0.12 s Any deviation from above is sinus tachycardia, sinus bradycardia or an arrhythmia Arrhythmia Formation Arrhythmias can arise from problems in the: •    Sinus node •    Atrial cells ...
Read more

ECG 2 -How to Analyze a Rhythm

• Step 1: Calculate rate. • Step 2: Determine regularity. • Step 3: Assess the P waves. • Step 4: Determine PR interval. • Step 5: Determine QRS duration. Step 1: Calculate Rate • Option 1 – Count the # of R waves in a 6 second rhythm strip, then multiply by 10. – Reminder: all rhythm strips in the Modules are 6 seconds in length. Interpretation? 9 x 10 = 90 bpm • Option 2 – Find a R wave that lands on a bold line. – Count the # of large boxes to the next R wave. If the second R wave is 1 large box away the rate is 300, 2 boxes - 150, 3 boxes - 100, 4 boxes - 75, etc.   – Memorize the sequence: 300 - 150 - 100 - 75 - 60 - 50 Step 2: Determine regularity • Look at the R-R distances (using a caliper or markings on a pen or paper). • Regular (are they equidistant apart)? Occasionally irregular? Regularly irregular? Irregularly irregular? Interpretation? Regular Step 3: Assess the P waves • Are there P waves? • Do the P waves all look alike? ...
Read more

ECG Basics

Normal Impulse Conduction Sinoatrial node--AV node--Bundle of His--Bundle Branches--Purkinje fibers The “PQRST” ►    P wave - Atrial   depolarization         QRS - Ventricular    depolarization           T wave - Ventricular   repolarization The PR Interval Atrial depolarization   + delay in AV junction  (AV node/Bundle of His)  (delay allows time for the atria to contract before the ventricles contract) Pacemakers of the Heart ►    SA Node - Dominant pacemaker with an intrinsic rate of 60 - 100 beats/minute. ►    AV Node - Back-up pacemaker with an intrinsic rate of 40 - 60 beats/minute. ►    Ventricular cells - Back-up pacemaker with an intrinsic rate of 20 - 45 bpm. The ECG Paper ►    Horizontally     One small box - 0.04 s     One large box...
Read more