Atrial ArrhythmiasPresented by: Kristi Metzger, CNP

Sanford Cardiovascular InstituteApril 7th, 2015

- Review of Atrial arrthymias

Overview

The heart has a conduction system separate from any other system

The conduction system makes up to PQRST complex

An arrhythmia is a disruption in this system

Understanding how the heart conducts normally is essential to understanding arrhythmias

Conduction System

SA Node Inter-nodal and

inter-arterial pathways

A-V node Bunkle of His Perkinje Fibers

Conduction System

The primary pacemaker of the heart

Each normal beat is initialted by the sinus node

Rate is 60-100 bpm Represents the P-

wave in the QRS complex or atrial depolarization

SA Node

Located in the septum of the heart

Receives impulse from SA node. Holds the signal before sending on the Bundle of His

Represents the PR segment of the complex

Serves as a “filter” for the ventricules

AV Node

Rate is 40-60 bpm Acts as a back up if

the SA node fails Where all

junctional rhythms originate

AV Node

First Degree AV Block (PR > .20 sec [1 big box])

II

P P P

.36

Site of delay most commonly the AV node, but may be localized to the His-Purkinje system

Second Degree AV Block - Type I (Wenkebach or Mobitz I Block)

P P P P

Block

II

• Example of 3:2 conduction ratio; general pattern, n:n-1• Note PR prior to block and post-block• Characteristic of AV nodal site of block

II

Block

P P P PP

• 4:3 conduction ratio• Note first RR longer than second RR

Second Degree AV Block - Type I(Wenkebach or Mobitz I Block)

II

P P P P P P

Second Degree AV Block - Type II (Mobitz II)

• Example of 3:2 conduction ratio; general pattern, n:n-1• Note fixed PR for all conducted beats• Characteristic of His-Purkinje system site of block

Block Block

Third Degree AV Block(Complete Heart Block)

V1 P P P PP

• P waves at 50-60 beats/min• QRS complexes (ventricular escape rhythm) at 35 beats/min• Atrial and ventricular activity are completely unrelated• Ventricular escape rhythm suggests His-Purkinje site of block

Represents the ventricles depolarizing (firing) collectively.

Origin of all ventricular rhythm

Rate of about 20-40 bpm

QRS complex

1. is there a P-wave for every QRS? P-waves are upright and uniform One p-wave preceding each QRS

2. Is the rhythm regular or irregular? Verify by assessing R-R interval Confirm by assessing P-P interval

3. What is the rate? Count the number of beats occuring in one minute Counting the p-wave will give you the atrial rate Counting the QRS will give you the ventricular rate

EKG interpretation

Normal◦ Heart Rate= 60-100◦ PR interval= 0.12-0.20 sec◦ QRS <0.12◦ SA node discharge 60-100/min◦ AV node discharge 40-60/min◦ Ventricular discharge 20-40/min

Summary

Normal sinus rhythm◦ Sinus node is the

primary pacemaker◦ One upright uniform

p-wave for every QRS

◦ Rhythm is regular◦ Rate is between 60-

100bpm

Normal Sinus Rhythm

One upright p-wave for every QRS

P wave upright in leads I and II, just as in normal sinus rhythm

Rhythm is regular Rate is less than 60 bpm

SA node is slower the normal Normal for many individuals

Sinus Bradycardia

One upright uniform p-wave for every QRS Rhythm is regular Rate is greater than 100bpm Usually 100-160bpm Causes are stress, anxiety, fever,

medications, or anything that increases oxygen consumption

Sinus Tachycardia

One upright uniform p-wave for every QRS

Rhythm is irregular Rate increases are you

breath in Rate decreases as you

breath out

Sinus Arrthymia

Sinus Arrest◦ Stop of sinus rhythm

Sinus pause One dropped beat is a

sinus pause

Sinus Arrest/Sinus Pause

No discernible p-waves preceding the QRS

Rhythm is grossly irregular

If HR is > 100 it is considered controlled, if HR is greater than 100 it is considered RVR

AV node acts as a “filter” blocking most of the impulses sent by the atria in attempt to control heart rate

Atrial Fibrillation

Background Most common cardiac arrhythmia in adults in

USA 3.1 million patients in 2005; 7.6 million by 2050

Lifetime risk 26% for men, 24% women

10% of all patients over 80 have AF

> 50% of all AF patients are 80 years or older

Lloyd-Jones DM, et. al, Circulation. 2004;110(9):1042Naccarelli GV et. Al, Am J Cardiol. 2009;104(11):1534

Atrial fibrillation

Prevalence increases with Age

Go AS, Hylek EM, Phillips K, et al. JAMA 2001; 285:2370

Thyroid abnormalities

Hypertension Obesity Obstructive sleep

apnea Family history Coronary artery

disease Valvular heart

disease

Triggers of atrial fibrillation

Rhythm Control Options

A) cardioversion B) anti-arrthymic

medications C) pulmonary vein

isolation/atrial fibrillation ablation if patient fails AA.

Rate control◦ AV nodal blocking

agents such as beta blockers or calcium channel blockers

◦ Pacemaker/AV node ablation

◦ Anticoagulation◦ Holter monitor to

assess average ventricular rate

Treatment of atrial fibrillation

Pulmonary Vein Isolation Roughly 70%

Atrial Fibrillation

Typical vs atypical atrial flutter. Right sided vs left sided.

More than one p-wave for every QRS complex

Demonstrates a “sawtooth” appearance Classified as ratio of p-waves per QRS.

(ex: 3:1 flutter)

Atrial Flutter

3 Main types◦ 1). AVNRT-AV nodal re-entry tachycardia

◦ 2). AVRT- accessory bypass tract

◦ 3). Atrial Tachycardia

SVT

Roughly 10% of the population has dual AV nodal physiology

Most common type of SVT

Comes on “like a light switch”

Can attempt vagel maneuvers to terminate

AVNRT (AV Nodal Re-entry tachycardia)

Look for retrograde p-wavesRhythm?

Also known as WPW

Wolf-parkinson-white syndrome

Delta wave seen on baseline 12 lead EKG

AVRT (AV re-entry tachycardia)

Delta wave

Pre-excitation on EKG

Atrial tachycardia is a form of SVT.

Impulse originating within the atria but outside the sinus node

Can be multifocal or unifocal

Known to cause cardiomyopathy if untreated especially in asymptomatic patients

Atrial Tachycardia

◦ Described as “fire works” on the forth of July◦ Many times it is MAT “multi-focal atrial tachycardia◦ Generally associated with lung disease such as emphysema and COPD.

Not always.

Atrial Tachycardia

RF vs cryo ablation

3D mapping systems such as CARTO

Ablation treatment

48 year old male: chief complaint palpitations- couple times a week

Large anterior MI 8 months ago, LAD was stented

EF 38%, mild MR NYHA 2 Meds- asa, plavix, lisinopril 20mg daily,

Metoprolol succinate 75mg bid

Case Studies

Rhythm on holter monitor when feeling palpitations

Add sotalol?

Add amiodarone?

ICD implant?

EP Study?

What would you do? Next Step

67 year old female admitted for syncope

EP consult to evaluate rhythm

Case Study

A) SVT

VT

Torsades

??

What is your diagnosis?

24 year old female referred to cardiology for palpitations by her PCP

Previously healthy Meds: BCP, levaquin for bronchitis, MVI Smoke 1 ppd x 5 years

Case Study

Case Study

33 year old female who was referred by her PCP.

Had a baseline EKG done for life insurance puposes

Case Study

Refused EP Study when offered. She was placed on BB and flecainide.

Was admitted on with palpitations.

Case Study