Putting It All Together 22 Putting It All Together Fast & Easy ECGs, 2nd E – A Self-Paced Learning Program

Analyzing ECGs The nine-step process can be used to analyze ECGs

Heart Rate Are either slow, normal, or fast Some dysrhythmias may produce more than one heart rate or even all three

Heart Rate

Regularity Dysrhythmias will either be regular or irregular Irregularity can be furthered characterize into the following groups: occasional or very slight sudden acceleration or slowing patterned total variable conduction ratio irregularity

Regularity

P Waves Depending on where each dysrhythmia originates, P waves are either present or not present If P waves are present, they are either normal or abnormal Sometimes there are more P waves than QRS complexes Also, with certain dysrhythmias, flutter or fibrillatory waveforms are present instead of P waves

P Waves

QRS Complexes Depending the lead viewed, QRS complexes should appear upright and narrow Abnormal QRS complexes Can vary from being only slightly abnormal to being extremely wide, notched, or slurred Extremely abnormal configurations are referred to as bizarre-looking because they deviate so far from normal Abnormal QRS complexes can occur when the pacemaker is initiated from above the ventricles as well as when it is initiated from within the ventricles

QRS Complexes

PR Intervals Normal PR intervals are within 0.12 to 0.20 seconds and constant in duration Abnormal PR intervals are those that are shorter than 0.12 seconds, are longer than 0.20 seconds, are absent, or vary in duration

PR Intervals

ST Segments ST segments are either present or not present If they are present, they are either normal or abnormal Abnormal ST segments are categorized: Elevated Depressed Indistinguishable (in certain dysrhythmias)

ST Segments ST Segments

T Waves T waves are either present or not present If they are present, they are either normal or abnormal Abnormal T waves include tall or peaked, heavily notched or pointed, inverted, flat, with bumps and those that take an opposite direction to the QRS complex

T Waves T Waves

QT Intervals Unless there are no Q waves and/or T waves, the QT interval is present QT intervals are normal or abnormal Abnormal QT intervals are: Prolonged Shortened Not measureable

QT Intervals

U Waves U waves are either present or not present

U Waves

Questions to Ask Is the rate of this dysrhythmia slow, normal or fast? Is this rhythm regular or irregular? If it is irregular, what type of irregularity is it? Are there P waves? What do they look like? Is each followed by a QRS complex? Are the QRS complexes present? If so, what do they look like? Are the PR intervals present? If so, what is their duration and is it constant? Are the ST segments present? If so, are they normal or abnormal? Are the T waves present? If so, are they normal or abnormal? Are the QT intervals measurable? If so, are they normal or abnormal? Are U waves present?

Practice Makes Perfect Analyze this ECG Answer: Rate: 125 BPM; Rhythm: regularly irregular; P waves: normal in underlying rhythm, absent in early beats; QRS complexes: QS complexes in underlying, wide and bizarre-looking in early beats; PR intervals: 0.18 seconds and constant in underlying rhythm, absent in early beats; ST segments: normal in underlying rhythm, absent in early beats; T waves: normal in underlying rhythm, deflect opposite direction to QRS complexes in early beats; QT interval: shortened 0.34 seconds in duration; U waves: none; Diagnosis: Sinus tachycardia with quadrigeminal PVCs 6 second strip I

Practice Makes Perfect Analyze this ECG 6 second strip Answer: Rate: 71 BPM; Rhythm: regular; P waves: unable to identify; QRS complexes: wide and bizarre-looking QS complexes; PR intervals: absent; ST segments: normal; T waves: deflect opposite direction to QRS complexes; QT interval: lengthened 0.56 seconds in duration; U waves: none; Diagnosis: Ventricular pacemaker I

Practice Makes Perfect Analyze this ECG 6 second strip Answer: Rate: 110 BPM; Rhythm: totally irregular; P waves: unable to identify; QRS complexes: normal RS complexes; PR intervals: absent; ST segments: normal; T waves: normal where seen; QT interval: normal 0.36 seconds in duration; U waves: none; Diagnosis: Atrial fibrillation with rapid ventricular response I

Practice Makes Perfect Analyze this ECG Answer: Rate: 70 BPM; Rhythm: regularly irregular; P waves: normal in underlying rhythm, absent in early beats; QRS complexes: pathological Q waves in underlying, wide and bizarre-looking in early beats; PR intervals: 0.18 seconds and constant in underlying rhythm, absent in early beats; ST segments: elevated in underlying rhythm, absent in early beats; T waves: inverted in underlying rhythm, deflect opposite direction to QRS complexes in early beats; QT interval: normal 0.40 seconds in duration; U waves: none; Diagnosis: Sinus rhythm with presumed quadrigeminal PVCs (as the tracing is limited to six seconds) 6 second strip I

Practice Makes Perfect Analyze this ECG 6 second strip Answer: Rate: 115 BPM; Rhythm: regular; P waves: normal; QRS complexes: narrow RS complexes; PR intervals: 0.12 seconds and constant; ST segments: normal; T waves: normal; QT interval: shortened 0.34 seconds in duration; U waves: none; Diagnosis: Sinus tachycardia I

Practice Makes Perfect Analyze this ECG 6 second strip Answer: Rate: 94 BPM; Rhythm: regular; P waves: absent; QRS complexes: wide and bizarre-looking; PR intervals: absent; ST segments: indistinguishable; T waves: deflect opposite direction to QRS complexes; QT interval: lengthened 0.60 seconds in duration; U waves: none; Diagnosis: Ventricular tachycardia I

Practice Makes Perfect Analyze this ECG 6 second strip Answer: Rate: 44 BPM; Rhythm: regular; P waves: normal; QRS complexes: narrow, slurred RS complexes; PR intervals: 0.28 seconds and constant; ST segments: normal; T waves: normal; QT interval: lengthened 0.42 seconds in duration; U waves: none; Diagnosis: Sinus bradycardia with 1st degree AV block I

Practice Makes Perfect Analyze this ECG Answer: Rate: 77 BPM; Rhythm: regular; P waves: normal; QRS complexes: wide; PR intervals: 0.20 seconds and constant; Diagnosis: Sinus rhythm with left bundle block I

Practice Makes Perfect Analyze this ECG Answer: Rate: 116 BPM; Rhythm: totally irregular; P waves: indiscernible; QRS complexes: QS complexes in many leads; PR intervals: absent; ST segments: elevated in leads V1 through V5; T waves: elevated in leads V2 and V3; Diagnosis: Atrial fibrillation with extreme axis deviation, anteroseptal infarct, possible lateral injury pattern, artifact in some leads I

Practice Makes Perfect Analyze this ECG Answer: Rate: 84 BPM; Rhythm: regular; P waves: wide; QRS complexes: wide, slurred rsR’S’ complexes; PR intervals: 0.12 seconds and constant; ST segments: normal; T waves: inverted in leads V1 to V3; QT interval: normal 0.36 seconds in duration; U waves: none; Diagnosis: Sinus rhythm with left atrial enlargement, right bundle branch block, possible inferior infarction – age undetermined I

Summary Use the nine-step process to analyze the ECG Determine the rate Determine rhythm Determine the presence and appearance of the P waves Determine the presence, appearance and duration of QRS complexes Determine the presence and duration of PR intervals Determine the presence and appearance of ST segments Determine the presence and appearance of T waves Determine the duration of the QT intervals Determine the presence of U waves Compare findings against the characteristics of the various dysrhythmias and conditions