Untitled Quiz

• Calipers and ECG paper are two tools used to analyze rhythms
• A rate chart can also be helpful but is non essential for understanding the data

ECG Paper measurements

• One small box on ECG paper represents 0.04 seconds
• Five small boxes make up one larger box, representing 0.2 seconds
• 5 mm or 1/2 mV is the equivalent of one large box on ECG Paper
• The height of one box is equal to 1 mm

Rhythm Interpretation Steps

• Obtain a 6 second strip
• Determine if there are QRS complexes and if they look the same - determining if the the shape is consistent and within normal limits
• Confirm if the rhythm is regular or irregular
• Calculate the heart rate
• Assess if there are P waves, confirming 1 P wave with every QRS complex
• Measure PR and QRS intervals which indicate sinus or AV node

Heart Rate Calculation Information

• Count the number of QRS complexes per minute to equal the ventriclar rate
• The number of P waves per minute equals the atrial rate
• Count the QRS complexes to easily discern heart rate

Heart Rate Method - 6 Second Strip

• This method is for calculation of irregular rhythms
• It is the least accurate of the methods
• Count the number of QRS complexes on a 6-second strip and multiply by 10 to get the heart rate
• Standard ECG paper marks 3 second intervals at the top of the strip

Heart Rate Method - Little Block

• Count the number of little blocks between QRS complexes and divide into 1500
• This is only accurate if the complexes/rhythm is regular

Regular Rhythm Evaluation

• If there are no more than 2-3 blocks difference then it is considered a regular reading
• Split blocks by 1/2 if the reading falls between blocks for accuracy

Regular Rhythms Interrupted by Premature Beats

• R-R intervals are regular until a beat occurs prematurely
• To calculate the heart rate, ignore premature beats
• Calculate the heart rate using the little block method on an uninterrupted part of the strip

Regular Rhythms Interrupted by Pauses

• R-R intervals are generally regular except for pauses
• Measuring the R-R interval can show pauses and BPM using blocks

Wave Measurements

• Normal PR interval = 0.12-0.20 seconds or 3-5 small blocks
• Normal QRS complex = <0.12 seconds, usually 1 - 2.5 blocks, less than 3 blocks
• Normal QT interval varies with heart rate, usually about = 0.40 (faster HR = shorter this measurement)

Analyzing Heart Rythm Complexities

• P Wave analysis should be evaluated for:
• Configuration by confirming if they all look alike?
• Confirm if the P waves upright in Lead II?
• Check that there is 1 P wave for every QRS.
• Establish if the P wave comes before QRS?
• Establish the Rate of arterial rhythm
• Confirm the PP interval is regular
• QRS Complex analysis should be evaluated for:
• Configuration by confirming if all the QRS complexes look alike?
• Checking that QRS complex follows each P wave
• Establishing the rate of the ventricular rhythm
• Verifying the RR interval is regular
• Check the duration by confirming the QRS interval is normal

Sinus Rhythm Characteristics

• Narrow QRS complexes of uniform shape are present
• QRS complexes are regularly spaced
• The heart rate is between 60-100 BPM
• Upright, rounded matching P waves are "married to" the QRS
• PR interval is constant from beat to beat at approximately 0.12-0.20 seconds
• QRS interval is normally <0.12 seconds

Arrhythmia Characteristics

• Arrhythmia heart ryhtms present as:
• Absent or abnormally shaped complexes
• Absent, multiple in number, or abnormally shaped P waves
• Abnormally shortened or prolonged PR intervals
• Abnormally prolonged QRS intervals
• Abnormally slow or fast heart rate
• Irregular rhythm with premature beats or pauses