EKG INTERPRETATION HCA PRACTICE GUIDE
2026 QUESTIONS AND ANSWERS VERIFIED
◉ QRS Complex. Answer: -ventricular contraction/depolarization
-<.12 seconds
◉ Q Waves. Answer: sometimes present and/or absent depending
on the lead
->25%-33.3% the size of the R wave means its significant
-Q wave MI carry a greater risk of early death or complications than
patient's with non-q wave MI's
◉ Significant Q Wave. Answer: - greater than 25%-33.3% of the R
wave means its significant
-full thickness of the myocardium is damaged
-ST segment elevation
◉ R Wave. Answer: R wave progression in precordial leads
◉ T Waves. Answer: -ventricular repolarization
-rounded and asymmetrical
-if symmetrical- cardiac pathology may be present (ischemia)
,◉ Abnormal T Waves. Answer: Hypokalemia: T wave gets tiny
Hyperkalemia: T wave gets really big
◉ U Waves. Answer: smaller curved wave that follows the T wave
-possible causes: normal, dig toxicity, hypokalemia,
hypomagnesemia
◉ PR Interval. Answer: the time period encompassing atrial
depolarization up to, but not including, the start of ventricular
depolarization
-0.12-0.20 seconds
-3-5 boxes long
◉ QRS Interval. Answer: -ventricular depolarization
-from the point of departure from the iso-electric line after the PR
interval to the return of the S wave back to the iso-electric line
-0.4-0.12 seconds, usually <0.12 seconds
◉ ST Segment. Answer: measured from the S wave of the QRS
complex to the beginnning of of the T wave; the time between
ventricular depolarization and depolarization, should be flat
(isoelectric)
-normally not depressed or elevated
,-in order for there to be ST elevation, it must be 1 box or more
elevation
◉ St segment depression. Answer: -ischemia
◉ ST segment elevation. Answer: -MI
◉ QT Interval. Answer: 0.34-0.43 seconds
-time taken for the entire electrical depolarization and
repolarization of the ventricles
◉ Common Causes of Dysrhythmias. Answer: -accessory pathways
-cardiomyopathy
-conduction defects
-heart failure
-myocardial cell degeneration
-myocardial infarction
-valvular disease
-acid-base imbalance, Etoh, caffeine, tobacco, connective tissue
disorder, drugs, electric shock, electrolyte imbalance
-emotional crisis, herbal supplements, hypoxia, shock, metabolic
conditions (hyperthyroidism), near-drowning, poisoning
, ◉ EKG Analysis. Answer: 1. Note the P wave. Is it upright or
inverted? Is there a P wave for every QRS wave. Evaluate the atrial
rhthym. Is it regular or irregular? Calculate the atrial rate.
2. Measure the duration of the PR interval Is it normal duration or
prolonged?
3. Evaluate the ventricular rhythm. Is it regular or irregular?
4. Calculate the Ventricular rate.
5. Measure the duration of the QRS complex. Is it normal duration or
prolonged?
-Assess the ST segment, is it isoelectric, elevated, or depressed.
-Measure the duration of the QT Interval. Is it normal duration or
prolonged?
-Note the T wave. Is it upright or inverted?
◉ Normal Sinus Ryhthm. Answer: Rate: 60-100
P Wave: Round/Normal
QRS: Normal (0.04-0.12, usually < 0.12)
Conduction: PR Interval - normal
Rythym: Regular
◉ Sinus Bradycardia. Answer: Rate: <60 bpm
P wave: round/normal
QRS: Normal (0.4-0.12, usually <0.12)
2026 QUESTIONS AND ANSWERS VERIFIED
◉ QRS Complex. Answer: -ventricular contraction/depolarization
-<.12 seconds
◉ Q Waves. Answer: sometimes present and/or absent depending
on the lead
->25%-33.3% the size of the R wave means its significant
-Q wave MI carry a greater risk of early death or complications than
patient's with non-q wave MI's
◉ Significant Q Wave. Answer: - greater than 25%-33.3% of the R
wave means its significant
-full thickness of the myocardium is damaged
-ST segment elevation
◉ R Wave. Answer: R wave progression in precordial leads
◉ T Waves. Answer: -ventricular repolarization
-rounded and asymmetrical
-if symmetrical- cardiac pathology may be present (ischemia)
,◉ Abnormal T Waves. Answer: Hypokalemia: T wave gets tiny
Hyperkalemia: T wave gets really big
◉ U Waves. Answer: smaller curved wave that follows the T wave
-possible causes: normal, dig toxicity, hypokalemia,
hypomagnesemia
◉ PR Interval. Answer: the time period encompassing atrial
depolarization up to, but not including, the start of ventricular
depolarization
-0.12-0.20 seconds
-3-5 boxes long
◉ QRS Interval. Answer: -ventricular depolarization
-from the point of departure from the iso-electric line after the PR
interval to the return of the S wave back to the iso-electric line
-0.4-0.12 seconds, usually <0.12 seconds
◉ ST Segment. Answer: measured from the S wave of the QRS
complex to the beginnning of of the T wave; the time between
ventricular depolarization and depolarization, should be flat
(isoelectric)
-normally not depressed or elevated
,-in order for there to be ST elevation, it must be 1 box or more
elevation
◉ St segment depression. Answer: -ischemia
◉ ST segment elevation. Answer: -MI
◉ QT Interval. Answer: 0.34-0.43 seconds
-time taken for the entire electrical depolarization and
repolarization of the ventricles
◉ Common Causes of Dysrhythmias. Answer: -accessory pathways
-cardiomyopathy
-conduction defects
-heart failure
-myocardial cell degeneration
-myocardial infarction
-valvular disease
-acid-base imbalance, Etoh, caffeine, tobacco, connective tissue
disorder, drugs, electric shock, electrolyte imbalance
-emotional crisis, herbal supplements, hypoxia, shock, metabolic
conditions (hyperthyroidism), near-drowning, poisoning
, ◉ EKG Analysis. Answer: 1. Note the P wave. Is it upright or
inverted? Is there a P wave for every QRS wave. Evaluate the atrial
rhthym. Is it regular or irregular? Calculate the atrial rate.
2. Measure the duration of the PR interval Is it normal duration or
prolonged?
3. Evaluate the ventricular rhythm. Is it regular or irregular?
4. Calculate the Ventricular rate.
5. Measure the duration of the QRS complex. Is it normal duration or
prolonged?
-Assess the ST segment, is it isoelectric, elevated, or depressed.
-Measure the duration of the QT Interval. Is it normal duration or
prolonged?
-Note the T wave. Is it upright or inverted?
◉ Normal Sinus Ryhthm. Answer: Rate: 60-100
P Wave: Round/Normal
QRS: Normal (0.04-0.12, usually < 0.12)
Conduction: PR Interval - normal
Rythym: Regular
◉ Sinus Bradycardia. Answer: Rate: <60 bpm
P wave: round/normal
QRS: Normal (0.4-0.12, usually <0.12)
