Common Arrhythmias Disclosures • I work for Virginia Garcia Memorial Health Center. • And I am a medical editor for Jones & Bartlett Publishing. Jon Tardiff, BS, PA-C OHSU Clinical Assistant Professor What a 12-Lead ECG can help you do • Diagnose ACS / AMI • Interpret arrhythmias • Identify life-threatening syndromes (WPW, LGL, Long QT synd., Wellens synd., etc) • Infer electrolyte imbalances • Infer hypertrophy of any chamber • Infer COPD, pericarditis, drug effects, and more! Arabic, Somali, Mai Mai, Pashtu, Urdu, ASL, and more! For example… WPW with Atrial Fib 55 66 Wolff-Parkinson-WhiteWPW Graphic synd. Same pt, converted to SR Drs. Wolff, Parkinson, & White 77 Another example: Dr. William Stokes—1800s 71 y.o. man with syncope This patient is conscious and alert! Third Degree Block 9 Treatment: permanent pacemaker 10 Lots of ways to read ECGs… Limitations of a 12-Lead ECG • QRSs wide or narrow? • Is it sinus rhythm or not? • Truly useful only ~40% of the time • Regular or irregular? • If not, is it atrial fibrillation? • Each ECG is only a 10 sec. snapshot • Fast or slow? • BBB? • P waves? • MI? • Serial ECGs are necessary, especially for ACS • Other labs help corroborate ECG findings (cardiac markers, Cx X-ray) • Confounders must be ruled out (LBBB, dissecting aneurysm, pericarditis, WPW, Symptoms: digoxin, LVH, RVH) • Syncope is bradycardia, heart blocks, or VT • Rapid heart beat is AF, SVT, or VT Conduction System Lead II P wave axis …upright in L II II R T P R U Q S …upright in L II R wave axis SA Node AV Node His Bundle BBs Purkinje Fibers 14 13 Q S Normal Sinus Rhythm Triplicate Method: 6-second strip: 6 seconds 300, 150, 100, Count PQRST cycles in a 6 75, 60, 50 second strip & multiply x 10 Quick, easy, sufficient Easy, & more accurate 300 150 100 75 60 6 seconds What is the heart rate? Horizontal axis is time (mS); vertical axis is electrical energy (mV) 16 1. Sinus Tachycardia 2. Atrial Fibrillation / Atrial Flutter 3. AV Nodal Reentry Tachycardia 4. Accessory Pathway / AVRT (WPW) 5. Atrial Tachycardia 6. Multifocal Atrial Tachycardia 7. Junctional Tachycardia 17 18 Sinus Tachycardia Treat the cause of the tachycardia—not the rhythm itself Originates in the sinus node. Usually a compensatory rhythm: Unless… “fight or flight” response. 19 20 Atrial Fibrillation Sinus Tachycardia—AMI! * * * * * * * * * * • Slow the heart rate with a Beta-blocker • MONA (morphine, oxygen, NTG, aspirin) • Stat cath lab for percutaneous coronary intervention (PCI) • or fibrinolytic Multiple reentry circuits within the atria generate multiple impulses. Suppresses SA node. Atrial rate 320 – 450. 22 Atrial Fibrillation Atrial refractory period • Very irregular rhythm • No P waves • Atrial fibrillatory waves often seen • >5 million Americans have AF Relative Refractory Period (vulnerable period) 232323 24 Sinus Rhythm with PACs… Atrial Fibrillation becoming Atrial Fibrillation R & L superior pulmonary veins, (especially the left) PAC PAC AF 25 Pulmonary vein isolation (ablation therapy) may cure26 AF Case report: Cause: hyperthyroidism Treatment: thyroid gland is irradiated. Patient makes full recovery 60-ish male, jogging with friends, becomes short of breath and continues an exceptionally active and productive life. and has to sit down. Is transported to Walter Reed Medical Center, and is diagnosed with paroxysmal atrial fibrillation. 27 28 Atrial Flutter Atrial Flutter with a rapid ventricular rate Rentry circuit in one of the atria. Atrial Flutter rate is 250 – 350 Makes “Saw-toothed” P waves, 29 saw-toothed P waves 303030 Adenosine revealing Atrial Flutter AV Nodal Reentry Tachycardia (AVNRT) Flutter waves Rentry circuit in the right atrium near AV Junction Incidence: ~60% of all paroxysmal supraventricular 31 tachycardias (excluding atrial fibrillation / flutter). 32 Accessory Pathway: AV Nodal Reentry Tachycardia (no P waves) AV Reentry Tachycardia (AVRT) AKA: WPW, LGL Drs. Wolff, Parkinson, & White Accessory pathway • 1 / 400 people have accessory pathways (bundle of Kent) • HR 150 – 280 / minute. 333333 34 • 40% of these patients get AF. ½% mortality rate. Orthodromic (normal) Case report: conduction 44 y.o. male comedian c/o episodes of rapid heart beat. Goes to the emergency department. WPW-Adensoine Conversion Valsalva maneuver Adenosine 6 mg IVP Antidromic (retrograde) conduction WPW pattern But he did What is the Syndrome? have WPW. HIPPA note: this is not WPW Richard Pryor’s actual ECG. short PR Delta waves Wide QRS A lethal combination: AF with WPW WPW—rapid mimicking ventricular rate! VT A-Fib with WPW degenerating to V-Fib Defibrillate! • Defibrillate! 120 – 200J There are other “short PR” syndromes: Lown-Ganong-Levine (LGL) LGL (48 y.o. F) LGL? Syndrome • Short PR interval • Normal QRS (NOT wide) • No “Delta” wave • Must also have episodes of tachycardia in order to be called LGL” syndrome” Atrial Tachycardia Atrial Tachycardia (with 2:1 & 3:1 conduction) P waves look different Rentry circuit or ectopic focus somewhere in one of the atria Incidence: ~10% of all paroxysmal supraventricular 43 444444 tachycardias (excluding atrial fibrillation / flutter). 45 A nice example of adenosine’s efficacy!46 Multifocal Atrial Tachycardia SVT Converting to SR with Valsalva Valsalva’s manuver manuver stopped (patient supine with legs elevated) Multiple Ectopic foci in both atria. 47 Similar to WAP, but faster than 100/min. 48 Junctional Tachycardia Multifocal Atrial Tachycardia lots of different looking P waves… • Automatic acceleration of the AV node • Uncommon rhythm 49 50 Junctional Tachycardia 1 Practice • No P waves (or inverted Ps) 51 525252 • Can be hard to distinguish from other SVTs Practice 2 Atrial Fibrillation 1 535353 545454 What is the Rhythm? 3 Atrial Tachycardia (pediatric patient) 555555 3 Practice 4 P’sPPPP QRS’s 57 585858 MAT — 4 Practice 5 Multifocal Atrial Tachycardia 595959 606060 5 Heart Blocks Atrial Fibrillation 616611 62 Different Kinds of Heart Blocks Sinus Arrest • Sinus Arrest • AV Blocks: • 1st Degree AV Block (PR > 20 msec. • 2nd Degree Block (some Ps don’t conduct) Wenckebach (PRI lengthens, dropped QRS) Mobitz (PR is constant, dropped QRS) • 3rd Degree Block (complete A-V dissociation) • Bundle Branch Block* (wide QRS > 120 msec) 63 64 Sinus Arrest “Escape” Rhythms (with Junctional Escape Rhythm) • Atrial Escape (weird Ps, normal PRI) • Junctional Escape (inverted Ps, short PRI) • Idioventricular Escape (no Ps, wide QRS) Junctional escape beats Causes: excessive vagal tone, atrial infarct or ischemia, antiarrhythmic drugs 65 66 Inverted Ps Junctional Escape Rhythm Idioventricular Rhythm • Sinus arrest • Wide QRS, regular rhythm • Inverted Ps following the QRSs • HR 15 – 40 / minute • HR 40 – 60 / minute 67 68 1st° Block = AV Node depression (Sometimes there is NO escape rhythm!) II R — Yikes! SR … Asystole T P U Treatment: CPR, Pacing, epinephrine 1 mg IV 69 Q S7070 First Degree Block 2nd Degree AV Block (dropped QRSs) Prolonged PR interval Causes: • antiarrhythmic drugs such as digoxin, calcium blockers, beta blockers, etc. dropped QRSs • anatomically long AV node • vagal stimulation nd 71 There are 2 kinds of 2 degree block…72 Wenckebach = 2nd Degree Block (Wenckebach) worse AV node depression [PRI lengthens, then a dropped QRS] PR gets longer dropped QRS Causes: • antiarrhythmic drugs such as digoxin, calcium blockers, beta blockers, etc. • AMI • Note: this is also called “2nd degree block, Mobitz I” 73 74 Mobitz = His bundle infarction, Bundle Branch Blocks or bundle branch infarction (QRS > 0.12 sec.) (right-sided lead) (left-sided lead) V1 R’ I notch r S Left BBB Right BBB (L I, V5, V6: (V1, MCL1: upright QRS rsR’ pattern) with a notch) 75 76 2nd Degree AV Block (Mobitz) Second Degree Block—Mobitz (PRI stays constant, then a dropped QRS) (2 Ps for every QRS, BBB pattern) P P P P P P P P V1 PR is constant dropped QRSs Causes: • Note: this is also called “2nd degree block, Mobitz II” • infarction of the His bundle, or both bundle branches. Mobitz is a precursor for Complete AV Block! 77 78 Third Degree AV Block = Infarction of the AV Node, or His Bundle, 3rd Degree AV Block or both Bundle Branches (complete A-V dissociation) Ps with no relation to the QRSs Causes: • Infarction of the AV Node, His Bundle, or both Bundle Branches • antiarrhythmic drugs such as digoxin, calcium blockers, beta blockers, etc. These patients need pacemakers 797979 80 What is the rhythm? 6 Sinus Arrest 6 no PQRS 81 82 1st Degree AV Block (long PRI) What is the rhythm? 7 7 The PR interval is 0.48 sec! How long is the PR interval? This patient is having an acute MI 83 84 What is the rhythm? What is the rhythm? 8 8 2nd Degree AV Block, Wenckebach PR gets longer P with dropped QRS 858585 868686 What is the rhythm? 2nd Degree AV Block, Mobitz 9 9 Dropped QRSs Dropped QRSs LBBB LBBB 878787 888888 10 10 What is the rhythm? What is the rhythm? Ps QRS • Third Degree AV Block (no relationship between Ps & QRSs) 89 90 Case History Idioventricular Rhythm (PEA) 52 y.o male, allergic to bees, collapsed 20 minutes after being stung by two hornets. Treatment: CPR, Pacing, epinephrine 1 mg IV (he made a rapid recovery and walked out of the hospital the next day) No pulse, agonal respirations 91 92 I also teach… • 12-Lead ECGs Acute coronary syndromes + more! • Just Say “NO” to Drug Seekers • and an ECG game: “The Rhythm Method™” “The Rhythm Method™” 93 [email protected].