conduction disorders

p wave duration

0.08-0.11 seconds

p-wave progression

SA node, internodal pathways, bachmann bundle, atrial myocytes

PR interval duration

0.12-0.2 seconds

QRS complex duration

0.06-0.12 seconds

QT interval duration

female ≤0.44 seconds

males ≤0.40 seconds

arrhythmia reasons HIS DEBS

hypoxia, ischemia, sympathetic stimulation, drugs, electrolyte disturbance, bradycardia, stretch

CHF diagnostic requirement

echo

first evaluation of EKG

P wave for every QRS and is there a T wave

sinus bradycardia threshold

<60 bpm

sinus tachycardia threshold

>100 bpm

hyperkalemia consequence

bradycardia or asystole

hypokalemia consequence

ventricular tachycardia

sinus brady CP

asymptomatic

dizziness, (pre)syncope, fatigue, weakness, confusion

when to intervene with sinus brady

HR <50-55 WITH SYMPTOMS

sinus brady diagnostics

EKG with rate <60, CBC, BMP, TSH

sinus brady causes

athletes, hypothyroidism, early MI (inf/post), high K+, rate limiting agents (nCCB, BB)

sinus brady tx

tx underlying cause IF SYMPTOMATIC

atropine, catecholamines (dopamine), dobutamine, epi, temporary pacer, permanent pacemaker

sinus tach considerations

anemia, hypovolemia, fever, pain, HF, hyperthyroidism, EtOH, lung disease

sinus tach CP

CP, SOB, dizziness, palpitations, heart racing

sinus tach conditions

sepsis, dehydration, anxiety, COPD, asthma

atropine action

speeds up HR

dopamine action

positive inotrope and speeds up HR

sinus tach diagnostics

EKG with rate 100-149, CBC, BMP, TSH

sinus tach tx

tx underlying cause IF SYMPTOMATIC

r/o arrhythmias, can add rate limiting agents (BB, nCCB)

supraventricular arrhythmias

afib, aflutter, PSVT, PAT, MAT, WPW

sinus arrhythmia

NSR but slightly irregular rate, benign

atrial fibrillation

arrhythmia with disorganized, rapid, irregular atrial electrical activation with loss of organized mechanical contraction

afib RF

aortic/mitral stenosis, CHF (systolic), DM, HTN, age >75, hx stroke, CAD/ischemia, EtOH, hyperthyroidism, OSA, obesity, post cardiac surgery, medications

afib types

paroxysmal, persistent, permanent, RVR, SVR

afib CP

palpitations, heart racing/flipping/butterlfy, SOB, dizziness, CP, fatigue, CHF sx

afib complications

stroke

afib PE

irregularly irregular rhythm, irregular pulse, tachy, CHF signs (edema)

afib EKG

irregular rhythm with NO P WAVE

afib labs

CBC, BMP, thyroid studies, trop

afib echo

look for valvular issues and establish EF

holter monitor

portable EKG to capture rhythms throughout the day over 24, 48, 72h

event monitor

small portable device recording electrical activity of heart for 2 weeks or 30 days

MUST BE ACTIVATED with symptoms, not continuous

paroxysmal afib

self terminating, maybe recurrent

persistent afib

fails to terminate, lasts >7d

permanent/chronic afib

persistent afib >1y

afib RVR

atrial fibrillation with rapid ventricular response

afib SVR

atrial fibrillation with slow ventricular response

afib tx

rate control with BB or CCB

restore sinus with cardioversion, antiarrhythmic meds, or catheter ablation

stroke risk stratification

CHADS2 score

action if CHADS >2

DOAC to prevent clots

stable low risk afib management

rate control - IV diltiazem (MC) or amiodarone

rhythm control - electrical cardioversion if antiarrhythmics don’t work

DOAC

stable low risk afib

<48h, hemodynamically stable

high risk STABLE afib management

rate control - IV diltiazem (MC) or amiodarone

rhythm control - electrical cardioversion if antiarrhythmics don’t work for 4-6 wks, TEE cardioversion

DOAC

TEE cardioversion

transesophageal echocardiogram with cardioversion to ensure no LA clot

high risk UNSTABLE afib management

ATTEMPT rate control - IV diltiazem (MC) or amiodarone

URGENT electrical cardioversion

anticoagulation - IV heparin or LMWH

CHADS-VASc oral antiarrhythmics

metoprolol, diltiazem, amiodarone, sotalol

unstable afib complications

increased risk of thromboembolism with emergent cardioversion (unstable pt outweighs risk)

cardioversion

synchronised, quick, low energy shocks to heart to restore typical heartbeat

afib ablation

catheter resets faulty electrical circuits in persistent afib

watchman device

left atrial appendage occluders, can prevent stroke in pts unable to do long term anticoags

atrial flutter

rapid, regular tachycardia with 2 to 1 block in AV node and ventricular rate 150 bpm

aflutter RF

COPD, valvular/structural heart disease, atrial septal defect, surgically repaired congenital heart disease, HTN, thyroid, afib

aflutter CP

palpitations, fatigue, mild dizziness, CHF sx, near syncope, DOE, SOB at rest, CP

aflutter PE

often normal

tachy, CHF signs (edema)

aflutter EKG

“sawtooth”pattern, look at inferior leads II, II, aVF

aflutter labs

CBC, CMP, thyroid, troponin

aflutter echo

look at valvular issues and EF baseline

aflutter tx

if CHADS-VASc >2 DOAC, cardioversion, BB, nCCB, amiodarone, sotalol

ablation definitive tx

rhythm?

sinus arrhythmia

rhythm?

atrial fibrillation

rhythm?

atrial fibrillation

rhythm?

atrial fibrillation

paroxysmal supraventricular tachycardia (PSVT)

tachyarrhythmia originating above ventricles

ventricular activation over purkinje system, narrow-complex tachycardia

paroxysmal supraventricular tachycardia (PSVT) population

young adults, no structural heart disease

paroxysmal supraventricular tachycardia (PSVT) RF

high caffeine intake, EtOH, marijuana

paroxysmal supraventricular tachycardia (PSVT) CP

palpitations, diaphoresis, dyspnea, dizziness, CP, syncope (rare)

paroxysmal supraventricular tachycardia (PSVT) EKG

regular narrow QRS tachycardia (QRS <120ms)

paroxysmal supraventricular tachycardia (PSVT) EKG types

AVNRT, AVRT

paroxysmal supraventricular tachycardia (PSVT) AVNRT

AV nodal re-entrant tachycardia with SVT p waves buried in QRS and rate 140-200

paroxysmal supraventricular tachycardia (PSVT) AVRT

AV reciprocating tachycardia with p waves hidden in QRS and T wave inversion and ST depression, rate 200-300

paroxysmal supraventricular tachycardia (PSVT) AVRT conditions

wolf-parkinson white or lown-ganong-levine syndrome

paroxysmal supraventricular tachycardia (PSVT) stable tx

1 - valsalva maneuver (bear down, cough, hold breath, carotid sinus massage)

2 - adenosine IV push or BB/nCCB

paroxysmal supraventricular tachycardia (PSVT) unstable tx

synchronized cardioversion

if recurrence refer to EP for ablation (very effective)

paroxysmal supraventricular tachycardia (PSVT) patient edu

reduce caffeine and EtOH

rhythm?

atrial flutter

multifactorial atrial tachycardia (MAT)

distention of RA from elevated pulm pressure causes multiple electrical firing with ventricular rate <150

must have 3 different p wave morphologies

multifactorial atrial tachycardia (MAT) RF

COPD, respiratory failure, alcohol + lung disease, infection, electrolyte disturbance

multifactorial atrial tachycardia (MAT) CP

DOE, dizziness, syncope, palpitations, CP, tachy

MAT vs afib

afib NO p waves, MAT HAS p waves with different shapes

wandering atrial pacemaker

same as MAT (3 different p wave morphologies) but rate <100

multifactorial atrial tachycardia (MAT) PE

irregularly irregular rhythm, rhonchi/wheeze, hypoxia

multifactorial atrial tachycardia (MAT) EKG

irregularly irregular narrow complex tachy with rate >100

multiple p wave morphologies w/at least 3 distinct within 1 lead

multifactorial atrial tachycardia (MAT) tx

nCCB (verapamil DOC)

tx underlying condition

wolff parkinson white (WPW)

congenital heart condition with extra accessory pathway (bundle of Kent) causing no delay in ventricular contraction leading to pre-excitation of ventricles

wolff parkinson white (WPW) considerations

genetic, typicaly not life threatening, can lead to SVT

wolff parkinson white (WPW) CP

asymptomatic

fluttering/pounding HB, palpitations, CP, SOB, dizziness, fainting, fatigue, anxiety

wolff parkinson white (WPW) EKG

shortened PR interval causing delta wave

wolff parkinson white (WPW) tx

ablation if symptomatic

cardioversion if unstable

wolff parkinson white (WPW) mnemonic

WPW wave (delta), PR short, wide (QRS base)

atrioventricular block (AVB)

conduction disturbance between atria and ventricles that can be physiologic (d/t vagal tone) or pathologic (ischemia, myocarditis, fibrosis)

blocks in AV node

first degree, second degree Mobitz type 1 (wenckebach)

blocks below AV node

second degree Mobitz type 2, third degree

first degree AVB

prolonged delay in AV conduction, common in sleep or well trained athletes

first degree AVB considerations

can be normal or d/t meds (CCB, BB, digitalis, antiarrhythmics)

first degree AVB CP

rarely symptomatic, often found incidentally on EKG