ECG Interpretation Advanced Cardiac Life Support William A

ECG Interpretation Advanced Cardiac Life Support William A. Shapiro, M. D. http: //anesthesia. ucsf. edu/shapiro advancing health worldwide TM Department of Anesthesia and Perioperative Care

Course Objectives & Description: • Recognize & initiate early management of periarrest conditions that may result in cardiac arrest • Manage cardiac arrest until return of spontaneous circulation, or transfer of care • Understanding of arrhythmia interpretation • Recognize the hemodynamic consequences of arrhythmias

Normal Sinus Rhythm Normal sinus rhythm results from the initiation of an electrical signal (the cardiac impulse) by cells of the sinus node at a rate appropriate to the age and state of activity of the individual, and then the propagation of that signal in an orderly manner through the atria, AV junction, ventricular specialized conducting system and the ventricular myocardium

Cardiac Conduction System Bachmann’s bundle Sinus node Internodal pathways AV node Bundle of His Left bundle branch Posterior division Anterior division Right bundle branch Purkinje fibers

Arrhythmia An arrhythmia reflects either abnormally rapid or slow impulse initiation by the sinus node, or interruption of the sinus rhythm by impulses originating from some other site in the heart, either for short or long periods of time

Mechanisms of Arrhythmias • Reentry • Automaticity –Altered normal automaticity –Abnormal automaticity • Triggered Rhythms due to DAD (delayed after depolarizations

Causes of Arrhythmias • Physiologic and Pathologic Processes – Vagal stimulation, Fever, Hypothermia – Electrolyte abnormalities, CNS problems – Hypovolemia, Pain, anaphylaxis, etc. • Preexisting Cardiac & Pulmonary Disease – Acute coronary syndrome, HTN, AODM – COPD, hypoxia, hypercarbia

The Electrocardiogram

The Electrocardiogram R T P Q PR Interval S QRS Interval U

The Electrocardiogram PR Interval QRS Interval QT Interval

Cardiac Conduction System Relationship of ECG to anatomy

Cardiac Conduction System Relationship of ECG to anatomy

ACLS THE ACLS PROVIDER IS: IN

Normal Sinus Rhythm • Rate 60 -100 beats per minute • Rhythm: Regular • P waves: Upright in Leads: 1, 2, AVF

Determining the Rate

Determining the Rate

Determining the Rhythm

Sinus Tachycardia • Rate: Greater than 100 beats per minute • Rhythm: Regular • P waves: Upright in Leads: 1, 2, AVF

Sinus Tachycardia • Rate: Greater than 100 beats per minute • Rhythm: Regular • P waves: Upright in Leads: 1, 2, AVF

Sinus Bradycardia • Rate: Less than 60 beats per minute • Rhythm: Regular • P waves: Upright in Leads: 1, 2, AVF

Sinus Bradycardia • Rate: Less than 60 beats per minute • Rhythm: Regular • P waves: Upright in Leads: 1, 2, AVF

Premature Atrial Complexes • P wave Rhythm: Irregular • P waves: Premature, often in the T-wave • QRS complex: Normal or widened P-wave

Premature Atrial Complexes • P wave Rhythm: Irregular • P waves: Premature, often in the T-wave • QRS complex: Normal or widened

Premature Atrial Complexes • P wave Rhythm: Irregular • P waves: Premature, often in the T-wave • QRS complex: (Normal or widened) or blocked Non conducted P-wave

Atrial Tachycardia • Rate: Atrial- 140 -240 bpm, p-waves hard to see • Rhythm: – P-wave- regular – QRS- 1 -1 conduction with atrial rates < 200 bpm – With atrial rates > 200 bpm, A-V conduction block common (less than 1 -1 conduction) • PR interval- depends on the origin of the p-wave • QRS- usually normal

Atrial Tachycardia P-Wave

Atrial Tachycardia with variable block P-Waves are regular at 160 bpm

Atrial Flutter • Rate: Atrial- 300 bpm (260 -320) • Rhythm: – P-waves- regular – QRS- 2 -1 conduction - 150 bpm, variable AV conduction with constant AV conduction ratio • P-waves: F-waves (Flutter), sawtooth pattern • QRS- usually normal, obviously sometimes wide

Atrial Flutter F-waves

Atrial Flutter with variable conduction (block)

Atrial Fibrillation • Rate: Atrial- rapid, Ventricular- Depends • Rhythm: – P-waves- irregular – QRS- beat to beat variability, Irregularly irregular • P-waves: From F-waves (Flutter) to absent • QRS duration- normal or wide

Atrial Fibrillation

Atrial Fibrillation

Atrial Fibrillation

Premature Junctional Complexes • • Rhythm: Irregular P waves: Retrograde PR interval: <. 12 sec or nonexistent QRS complex: Normal or widened

Premature Ventricular Complexes • • Rhythm: Irregular P waves: Usually not seen QRS complex: Wide >. 12 sec Compensatory pause

Premature Ventricular Complexes Compensatory pause This distance is double the sinus distance This is the sinus and the QRS distance

Premature Ventricular Complexes • Unifocal PVCs • Multifocal PVCs

Premature Ventricular Complexes Compensatory pause This distance is double the sinus distance This is the sinus and the QRS distance Interpolated PVC

Premature Ventricular Complexes Ventricular Bigeminy Pairs of PVCs

Premature Ventricular Complexes PVC on T-wave precipitating Ventricular Tachycardia

Ventricular Tachycardia • Rate: Approx 100 -230 bpm • Rhythm: Usually regular • P waves: Usually not seen – Independent A and V activity – A-V dissociation • QRS complex: Wide >. 12 sec • Capture beats, fusion beats

Ventricular Tachycardia

Ventricular Tachycardia Polymorphic Ventricular Tachycardia

Ventricular Fibrillation • • Rate: Rapid- no effective cardiac rhythm Rhythm: Irregular P, QRS, T- waves: Absent No blood pressure!

Ventricular Fibrillation Course VF Fine VF

Ventricular Fibrillation

Ventricular Asystole • P, QRS, T- waves: Complete absent of cardiac electrical activity • Complete absent of effective cardiac pumping function

Acute Coronary Syndromes

Acute Coronary Syndromes

Acute Coronary Syndromes

Review

Review Atrial Fibrillation

Review Atrial Fibrillation Sinus Rhythm

Review Atrial Fibrillation Sinus Rhythm Acute Coronary Syndrome

Review

Review Asystole

Review Asystole Fine Ventricular Fibrillation

Review Asystole Fine Ventricular Fibrillation Coarse Ventricular Fibrillation

Review

Review Ventricular Tachycardia- ?

Review Ventricular Tachycardia- ? Premature Ventricular Complex (PVC)

Review Ventricular Tachycardia- ? Premature Ventricular Complex (PVC) Ventricular Tachycardia

Review

Review Ventricular Tachycardia

Review Ventricular Tachycardia

Review Ventricular Tachycardia (Paroxsymal) Atrial Tachycardia (SVT)

Review

Review Paroxsymal Atrial Tachycardia (SVT)

Review Paroxsymal Atrial Tachycardia (SVT) Atrial Flutter

Treatment of All Cardiac Arrhythmias All arrhythmias that are hemodynamically significant require immediate cardioversion, defibrillation, or cardiac pacing

Break Time

AV Block • Why is it important? • Where is the block? • What’s a pacemaker anyway?

Rates of Intrinsic Cardiac Pacemakers • Primary pacemaker –Sinus node (60 -100 bpm) • Escape pacemakers –AV junction (40 -60 bpm) –Ventricular (< 40 bpm)

Escape Patterns

Junctional Escape Complexes • Rate: Junctional escape rate 40 -60 bpm • Rhythm: Junctional • P-waves: Retrograde, inverted in 2, 3, avf –Before, during, or after QRS • QRS: Normal or wide

Junctional Escape Complexes

Junctional Escape Complexes Junctional Rhythm

Ventricular Escape Complexes

Classification of AV Block • Partial – First-degree AV block – Second-degree AV block, Types I (Wenckebach) and Type II • Complete AV block – Third-degree AV Block “You should know the major AV blocks because important treatment decisions are based on the type of block present. ” Page 79

First-Degree AV Block • Rhythm: Regular • 1: 1 Conduction: Each P-wave is followed by a QRS complex • PR Interval: >. 20 secs • QRS Complex: Generally normal • Hemodynamic implications: None

First-Degree AV Block

Second-Degree AV Block, Type I • Rate: – Atrial- regular – Ventricular- less than the atrial rate • Rhythm: – Atrial- regular – Ventricular- progressive shortening of the R-R interval before pause • PR: progressive increase until P blocked • Why is knowing this important

Second-Degree AV Block, Type I

Second-Degree AV Block, Type II • Rate: – Atrial- regular – Ventricular- less than the atrial rate • Rhythm: – Atrial- regular – Ventricular- usually irregular • PR: constant when present • Why is knowing this important

Second-Degree AV Block, Type II

Third-Degree AV Block • Rate: – Atrial- regular – Ventricular- less than the atrial rate • Rhythm: – Atrial- regular – Ventricular- regular • PR: varies with every beat • QRS: normal or wide • Hemodynamics: No atrial contribution

Third-Degree AV Block

Third-Degree AV Block

Electrical Therapy All arrhythmias that are hemodynamically significant require immediate cardioversion, defibrillation, or cardiac pacing

Electrical Therapy • Understand when cardioversion or defibrillation is indicated • Know the difference between unsynchronized and synchronized shocks • Energy doses for specific rhythms • Challenges of delivering shocks safely and effectively- may include iv sedation

Cardioversion and Defibrillation • Understand when cardioversion or defibrillation is indicated SYMPTOMS

Hemodynamically Significant Tachycardia or Bradycardia • • • Hypotension (Systolic BP < 80 mm. Hg) Altered mental status Congestive heart failure Angina Does not respond promptly to medical management, if tried

Cardioversion and Defibrillation The electric shock depolarizes all excitable myocardium, interrupts reentrant circuits, discharges foci, and establishes electrical homogeneity

Cardioversion and Defibrillation • AED: Learn the one in your setting • Biphasic: 200 watt-seconds (joules) • Monophasic: 360 watt-seconds (joules) “The interval from collapse to defibrillation is one of the most important determinants of survival from cardiac arrest. ” Page 35

Cardioversion and Defibrillation

Cardioversion and Defibrillation Procedure for Defibrillation • • • Power on Apply pads Analyze the rhythm Select the energy level Clear the area Discharge the device

Cardioversion and Defibrillation Cardioversion • Know when cardioversion is indicated • Synchronized vs unsynchronized shock • What energy level for what arrhythmias • Establish iv and consider sedation

Cardioversion and Defibrillation Cardioversion Anesthetic (amnestic) Agents A physician skilled in airway management (ie. , an anesthesiologist) should be in attendance, and all necessary equipment for emergency resuscitation should be immediately available

Cardioversion and Defibrillation Cardioversion The electric shock depolarizes all excitable myocardium, interrupts reentrant circuits, discharges foci, and establishes electrical homogeneity

Cardioversion and Defibrillation Synchronized cardioversion (defibrillation) uses a sensor to deliver the shock with the peak of the QRS complex. The goal is to avoid the shock on the T-wave, “R-on-T”, which is known to induce ventricular fibrillation in unstable hearts

The Electrocardiogram PR Interval QRS Interval QT Interval

Cardioversion and Defibrillation Synchronization Energy Selection • Atrial flutter & SVT: 50 -100 J (monphasic) • Atrial fibrillation: 100 -200 J (monophasic) • Ventricular tachycardia: 100 -200 J

Cardioversion and Defibrillation Procedure for Cardioversion • • Power on Apply pads Turn on the SYNC control Analyze the rhythm Select the energy level Clear the area Discharge the device

Cardioversion and Defibrillation Complications of Cardioversion • Ventricular fibrillation occurs • Turn off the SYNC control • Charge to 200 J (or more) • Clear the area • Discharge the device

Review

Review 3 rd Degree Heart Block

Review 3 rd Degree Heart Block 2 nd Degree Type II Block

Review 3 rd Degree Heart Block 2 nd Degree Type II Block 2 nd Degree Type I Block

Review

Review 1 st Degree Heart Block

Review 1 st Degree Heart Block Junctional Escape Rhythm

Review 1 st Degree Heart Block Junctional Escape Rhythm Sinus Bradycardia

Review Ventricular Tachycardia- ?

ECG Interpretation Advanced Cardiac Life Support That’s it- Now go forth and save lives. Make us all proud you’re from UCSF William A. Shapiro, M. D. http: //anesthesia. ucsf. edu/shapiro advancing health worldwide TM Department of Anesthesia and Perioperative Care