Cardiac Telemetry Self Study: Part One Cardiovascular Review 2017 THINGS TO REMEMBER

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1 Please review the above anatomy of the heart. THINGS TO REMEMBER There are 3 electrolytes that affect cardiac function o Sodium, Potassium, and Calcium When any of these electrolytes are out of the normal range you may see changes in your cardiac rhythm and in your rhythm strip analysis Normal contraction of the atria and ventricles is sequential Automaticity - ability to automatically generate electrical impulse o The SA node is normally in control and is called the pacemaker of the heart because it possesses the highest level of automaticity. If the SA node fails to generate electrical impulses at its normal rate or stops functioning entirely, or if the conduction of these impulses is blocked, pacemaker cells in secondary pacemaker sites can assume control as pacemaker of the heart but at a much slower rate. In general the farther away the impulse originates from the SA node, the slower the rate. This does not apply to Sinus Bradycardia; which originates from the SA node at a slower pace than normal

2 Cardiac Electrical Conduction Sinus Atrial (SA) Node; High in the R atrium. Pacemaker of the heart. Rate of bpm Atrio-Ventricular (AV) Node; low R atrium near the Tricuspid valve. o Slows conduction from atria-ventricles through Bundle of His, allowing time for atria to empty blood into ventricles. Impulse rate of bpm. Back up pacemaker to SA node Bundle of His-Purkinje Fibers; Upper portion of the septum connects the AV node with the two bundle branches. Purkinje fibers are hair like fibers along the endocardial surface of both ventricles. Impulse rate bpm.

3 Sequence of Excitation Impulse passes from SA node AV node ventricles via the atrioventricular bundle (Bundle of His) Bundle of His splits into two pathways in the interventricular septum (Bundle Branches, R & L) R & L Bundle branches carry the impulse towards the apex of the heart Purkinje fibers carry the impulse to the heart apex and ventricular walls Segment Representation P wave: represents depolarization/spread of electrical impulse through R & L atria PR interval: conduction of impulse through AV node, Bundle of His, R/L Bundle Branch & Purkinje fibers QRS: Depolarization of ventricles (Q, R & S waves) ST segment: represents early repolarization of ventricles J point: where QRS stops and ST segment begins T wave: represents ventricular repolarization QT interval: Represents total Ventricular activity Artifact: distortion of ECG tracing by non cardiac electrical activity like:- loose electrode, patient movement, muscle activity, interference o Depolarization: cardiac cell is stimulated and positively charged. Greater Na/Ca in the cell o Repolarization: returning back to its resting state of negative charge.

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8 The 6 Step Approach to strip interpretation Rate? ( Tachy, Brady, normal SR) Rhythm? (Regular or Irregular) P-R Interval Normal? ( sec) QRS complex normal? ( sec or 0.11) (does every QRS look the same?) QT Interval ( ) Usually gender/age dependent P-wave upright & preceding every QRS? (one P- wave for every QRS) (does every P wave look the same?)

9 Interventions If you see a lethal arrhythmia(v-fib, asystole, v-tach without a pulse, etc.) call a CODE BLUE and Start your ACLS Protocol If you have a change in rhythm, notify your supervisor, gather pertinent data (i.e. history, recent labs, prior rhythm, medications) and notify the physician if applicable Measurements

10 Let s Review some rhythm strips

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18 Let s Practice! For each practice strip, use the 6 step approach to identify: Rate, Rhythm, P-R interval, QRS complex, QT interval, and P-wave characteristics sec or widened? sec? Interpretation: sec or widened? sec?

19 sec or widened? sec? sec or widened? sec?

20 or widened? sec? sec or widened? sec?

21 sec or widened? sec? or widened? sec?

22 or widened? sec? or widened? sec?

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24 sec or widened? sec? sec or widened? sec?

25 sec or widened? sec? sec or widened? sec? EKG Arrhythmia Practice Drill Resources

26 EKG Academy EMS Success, Education, Opportunity (SEO) Heart Blocks video ECG Workout (workbook) Huff, J. (1997). ECG workout: Exercises in arrhythmia interpretation. Philadelphia: Lippincott. Aehlert, B. (2002). ECGs made easy (2 nd ed.). St. Louis: Mosby.