Cardiac Arrhythmias and Conduction Abnormalities Andrew P. Wilper, MD

Goals and Objectives Diagnose common cardiac arrhythmias  Discuss importance of, and indications for anticoagulation in atrial fibrillation Diagnose common cardiac conduction abnormalities

PART 1 We Are a Part of the Rhythm Nation

You are seeing a 61-year-old man in urgent care. He complains of light headedness. He denies chest pain and dyspnea. ATRIAL FIBRILLATION Irregularly irregular & undulating baseline

ATRIAL FIBRILLATION Rule #1 Narrow and irregularly irregular is atrial fibrillation until proven otherwise. Why did it occur? MI? PE? Hyperthyroidism? ETOH? Valvular Disease? Treatment Rate control: diltiazem, beta blocker, digoxin, ablation Rhythm control? Generally no unless very poor output Anticoagulation Embolic risk ~ 5%/year CHADS2 points score NNT CHF10417Review VASc RF HTN11125Anticoagulation Age > Anticoagulation DM1333Anticoagulation Secondary (TIA, CVA)2427 Anticoagulation 5/644Anticoagulation

What about CHADS2=0? Consider use of additional risks in form of CHA2DS2-VASc – Gives two points for age 75 years and older – An additional point for age – An additional point for females – An additional point for vascular dz (CAD, PVD) – Better identifies risk among CHADS2=0 patients

Skanes. Can Jour Cardiol ,

RE-LY. NEJM. 2009

You are seeing a 44 yo female with a complaint of palpitations.

What was the rhythm? What was the treatment? What is the problem? Supraventricular tachycardia Adenosine IV Wolff-Parkinson-White Rate 180 QRS Morphology when in sinus rhythm

SUPRAVENTRICULAR TACHYCARDIA (SVT) RATE (typically ~ 180) Why did it occur? Accessory pathway? ETOH? Stimulants? Caffeine? Treatment Vagal Maneuvers Adenosine (temporary A-V blockade) Cardiovert if unstable EPS w/ablation for WPW

Common SVT Characteristics Sinus tachycardia EATMATAfibAflutterWPW Rate> >100Variable (can be fast or slow) Vent rate: RegularityRegular Irregularly irregular Usually regular Irregular or regular P waveEctopic focus different At least 3 different morphologies NoneSawtoothedBuried P:QRS ratio 1:1 NoneMost commonly 2:1, others are 3:1 and 4:1 1:1 if you can see it PR intervalNormal to slightly shortened Ectopic focus with different interval VariableNoneVariableVery shortened; QRS is also typically wide

You are seeing a patient in the ED with a complaint of palpitations. Recent history of pericarditis.

Rate 150 ATRIAL FLUTTER Flutter waves

ATRIAL FLUTTER Rule #2 Narrow, regular, and 150 is atrial flutter until proven otherwise. Why did it occur? CHF? COPD? Pericartidis? Recent Cardiac Surgery? Treatment -Usually goes away or converts to A-fib -Anticoagulation-similar approach to atrial fibrillation -Radiofrequency ablation of reentrant circuit

FAST, NARROW RHYTHMS Irregularly irregular (Rule #1) A-FIB Rate > Rhythm ControlCHADS2 (Remember MAT) Regular at ~ 150 (Rule #2) A-FLUTTER Adenosine for diagnosis Regular > 150 SVTAccessory pathway (ablation) Stimulants Adenosine for treatment

You are seeing a 61-year-old man in urgent care. He complains of light headedness. He denies chest pain and dyspnea. V – TACH 1. Abnormal and wide qrs (>120 ms) with secondary st and t wave changes, qrs concordance in V1-V6 2. Rate Regular or slightly irregular 4. Abrupt onset and termination 5. AV dissociation 6. Capture beats-regular qrs from atrial p wave 7. Fusion Beats-partial depolarization by atrial and ventricular impulse

You are called to the bedside of a patient with a history of drug-induced long QT syndrome.

Diagnosis?

Polymorphic Ventricular Tachycardia

Polymorphic VT 1)Paroxysms of VT with irregular RR interval 2)Ventricular rate )Two or more cycles of qrs complexes with alternating polarity 4)Changing amplitude of qrs complexes in sinusoidal fashion 5)If prolonged QTc=Torsades de pointes

FAST, WIDE RHYTHMS Ventricular Tachycardia QRS > 0.14 ms QRS concordance in V1-6 Notching in V1 down stroke SVT with LBBB deep S in V1, V2 wide R in I, V6 T-wave opposite terminal QRS SVT with RBBB some R wave in V1 prominent S in V6 T-wave opposite in III, V1-3 WiLLiaM MaRRoW=W in V1 and for M in V6 for LBBB, RBBB opposite

V tach-fusion beat

You are seeing a 61-year-old man in urgent care. He complains of light headedness. He denies chest pain and dyspnea. 2 o, Mobitz type I (Wenckeback ) Grouped beating Lengthening P-R interval Dropped beat

APPROACH TO HEART BLOCK (P = QRS) Are there as many P waves as QRS complexes? NO YES1 o (P-R =) Is the P-R interval always equal?YES 2 o, Mobitz II NO (QRS =) Is the QRS interval always equal?YES 3 o NO 2 o, Mobitz I (Wenckebach)

0.10 Sinus Node Wenckebach (Sick Sinus) SA A AV V AV Wenckebach SA A AV V Sinus Wenckebach

54 year old male with intermittent dizziness

Unchanging PR with unexpected dropped beats Diagnosis=Mobitz II Block

When to get help!

Name the Rhythm

You review the chart….

And find this

Name the Rhythm Paced Rhythm Motion Artifact Aberrantly Conducted Native Beats

42 year old, screening physical RBBB 1. QRS >0.12 sec (in ANY lead) – look for this first 2. Slurred S wave in I and V6 – look for this second 3. RSR’ pattern in V1 with R’ taller than R (“Rabbit ears”) 4. Should be predominately positive in V1 – look for this only AFTER looking for the previous 2 criteria

Right Bundle Branch Block Clinical Correlates-RVH, sudden increase in right ventricular pressure with stretch (as in pulmonary embolism), Cor Pulmonale, myocardial ischemia, infarction, or inflammation (myocarditis), hypertension. Caveats: Sometimes you will see a qR’ wave indicating an anteroseptal MI in V1 (floppy eared rabbit). You cannot diagnose RVH in RBBB

75 yo male presents to establish care, prior history of lymphoma LBBB 1. QRS duration >0.12 sec 2. Broad, monomorphic (meaning all positive or all negative) R waves in I and V6, with no Q waves 3. Broad, monomorphic S waves in V1; may have small r wave

Left Bundle Branch Block Clinical associations: HTN, CAD, valvular heart disease (rheumatic heart disease), endocarditis, cardiomyopathy, infiltrative diseases of the heart, prior XRT Caveats: You cannot Dx LVH or RVH in patients with LBBB. Infarction is tricky to diagnose in LBBB, but possible

Delays Intraventricular Conduction Delay (IVCD) Criteria: – QRS duration > 0.12 seconds – Doesn’t qualify for LBBB or RBBB **When this is seen, look for hyperkalemia

Blocks Hemiblocks (Left Anterior Fascicular Block, Left Posterior Fascicular block) A few words: The Left bundle splits into the left anterior fascicle and the left posterior fascicle

Blocks Criteria: Left Anterior Hemiblock/Fascicular Block (fairly common) – LAD with axis at –30 to –90 degrees – qR complex or an R wave in lead 1, AvL – An rS complex in lead III and usually in II and aVF – Easy shortcut: LAD?  yes, then check lead II  – if net vector is negative  LAHB

LAFB ECG Axis?Left QRS duration? <120ms Net Vector in II? Negative

Causes of LAFB CAD Hypertension Valvular disease Degenerative disease of the conducting system Sclerosis of the left cardiac skeleton Myocardial fibrosis Normal Variant (2-5%)

Blocks Left Posterior Hemiblock/ Fascicular Block (fairly rare) – RAD with axis – S wave in lead I and a q in III – Exclusion of RAE and/or RVH

Left Posterior Hemiblock Axis? Right QRS? <120 ms rS in I and aVL qR in III and aVF

Causes of LPFB Similar to LAFB Cardiomyopathies Chagas disease Myocarditis Hyperkalemia Acute cor pulmonale

Note RBBB+LAFB or RBBB + LPFB commonly referred to as bifascicular blocks

Practice!

Normal Sinus Rhythm

VT A fib w/BBB

A Fib LBBB

LVH with strain NSR with PAC Rate related LBBB

Sinus Tachycardia, A-V dissociation RBBB LAFB NS ST/T abn

Thank you