EKG Interpretation
80 flashcards by MentisLibrary
Read a rhythm strip with confidence. Intervals, axis, lead groups and the systematic approach, then the rhythms and conduction blocks, the ischemia patterns, and the electrolyte and device findings that change what you are looking at.
- What is the standard paper speed of a 12 lead EKG?
- 25 millimeters per second
- What does one millimeter of vertical height represent on a standard EKG?
- 0.1 millivolt, with standard calibration of 10 millimeters per millivolt
- What does the P wave represent?
- Atrial depolarization
- What does the QRS complex represent?
- Ventricular depolarization
- What does the T wave represent?
- Ventricular repolarization
- Why is atrial repolarization not seen on the EKG?
- It is small in amplitude and buried inside the much larger QRS complex
- What is the normal PR interval?
- 0.12-0.20 seconds, or three to five small boxes
- What is the normal QRS duration?
- Under 0.12 seconds
- What is the normal QT interval?
- Corrected QT under about 440 milliseconds in men and 460 milliseconds in women
- Why must the QT interval be corrected for heart rate?
- The raw QT shortens as heart rate rises, so an uncorrected value cannot be compared across rates
- How do you estimate heart rate with the 300 method?
- Count large boxes between two consecutive R waves and divide 300 by that number
- How do you estimate heart rate on an irregular rhythm?
- Count the QRS complexes in a 6 second strip and multiply by 10
- What defines normal sinus rhythm?
- A regular rhythm at 60-100 beats per minute with an upright P wave before every QRS and a constant normal PR interval
- What is sinus bradycardia?
- A sinus rhythm slower than 60 beats per minute
- What is sinus tachycardia?
- A sinus rhythm faster than 100 beats per minute
- What is sinus arrhythmia?
- A sinus rhythm whose rate varies with the respiratory cycle, speeding on inspiration and slowing on expiration
- What is a premature atrial contraction?
- An early beat originating in atrial tissue outside the sinus node
- What is a premature ventricular contraction?
- An early wide beat originating below the bundle of His
- What is ventricular bigeminy?
- A pattern in which every normal beat is followed by a premature ventricular contraction
- What is atrial fibrillation?
- A chaotic atrial rhythm with no organized P waves and an irregularly irregular ventricular response
- What is atrial flutter?
- An organized rapid atrial rhythm producing a sawtooth baseline, usually around 300 atrial beats per minute
- What is supraventricular tachycardia?
- A fast regular narrow complex rhythm above 150 beats per minute originating above the ventricles
- What is multifocal atrial tachycardia?
- An irregular atrial tachycardia with at least three distinct P wave morphologies
- What is a junctional rhythm?
- An escape rhythm arising from the AV junction at about 40-60 beats per minute
- What is an idioventricular rhythm?
- A slow wide complex escape rhythm from the ventricles at about 20-40 beats per minute
- What is monomorphic ventricular tachycardia?
- Three or more consecutive ventricular beats at over 100 per minute, all with the same wide QRS shape
- What is torsades de pointes?
- A polymorphic ventricular tachycardia in which the QRS amplitude twists around the baseline
- What is ventricular fibrillation?
- Chaotic disorganized ventricular electrical activity with no effective contraction and no cardiac output
- What is asystole?
- The complete absence of ventricular electrical activity, seen as a flat line
- What is pulseless electrical activity?
- Organized electrical activity on the monitor with no palpable pulse