cardiac implanted electronic devices

Cardiac Implanted Electronic Devices

Pacemakers, Defibrillators, Cardiac Resynchronization Devices, Loop Recorders, etc.

The Miracle of Living February 21, 2018 Matthew Ostrom MD,FACC,FHRS

Division of Cardiology and Cardiac Electrophysiology Torrance Memorial Medical Center

https://www.torrancememorial.org/

Reasons for Implanted Device Treatment of slow heart rates(bradycardia): Pacemaker Treatment of congestive heart failure/cardiomyopathy:

Cardiac Resynchronization Device (CRT) or defibrillator (ICD).

Treatment/Prevention of Sudden Cardiac Arrest: ICD Monitoring for dangerous heart rhythms after

syncope(passing out), stroke, or other serious cardiac condition: Implantable loop recorder (ILR)

Symptoms of Bradycardia (Slow Heart Rate) Usually occurs when heart is not pumping enough blood to meet

body's needs. This often happens when the heart rate is very slow or remains slow for a long period of time.

Related to organ hypo-perfusion and include: Dizziness or lightheadedness Fainting (syncope) or near-fainting Tiredness (fatigue) Shortness of breath Palpitations Chest pain (angina) Increased difficulty exercising Confusion or difficulty concentrating Some people with bradycardia do not have symptoms

Yan G, Kowey PR. Management of Cardiac Arrhythmias. New York, NY: Springer Science; 2011.

Classifications of Bradyarrhythmias

There are two types of bradyarrhythmias Those related to problems with impulse formation

Those related to problems with impulse conduction

Sinus node

AV node

Classification of Bradyarrhythmias

Problems with Impulse Formation

Sinus Arrest Sinus Bradycardia Chronotropic

Incompetence Brady/Tachy

syndrome

Sinus Arrest

Failure of sinus node discharge

Absence of atrial depolarization

Periods of ventricular asystole

May be episodic as in vaso-vagal syncope, or carotid sinus hypersensitivity

May require a pacemaker

Presenter

Presentation Notes

Sinus arrest occurs when there is a pause in the rate at which the SA node fires. With sinus arrest there is no relationship between the pause and the basic cycle length.

Sinus Bradycardia

Sinus Node depolarizes very slowly

If the patient is symptomatic and the rhythm is persistent and irreversible, may require a pacemaker

Presenter

Presentation Notes

Sinus bradycardia occurs when the SA node fires at an abnormally slow rate (< 60 bpm).

Chronotropic Incompetence

The heart rate is unable to change in response to the body’s metabolic demand.

Griffin, BP. Manual of Cardiovascular Medicine. Philadelphia, PA: Lippincott, Williams, and Wilkins; 1999.

Brady/Tachy Syndrome

Intermittent episodes of slow and fast rates from the SA node or atria Brady < 60 bpm

Tachy > 100 bpm

AKA: Sinus Node Disease/ Sinus Node Dysfunction Patient may also have periods of AF (Atrial Fibrillation) and

chronotropic incompetence Most common pacing indication

Curtis, AB, Fundamentals of Cardiac Pacing. Sudbury, MA: Jones and Bartlett Publishers; 2010.

Presenter

Presentation Notes

Brady-tachy syndrome occurs when the SA node has alternating periods of firing too slowly (< 60 bpm), and too fast (> 100 bpm). Brady-tachy syndrome often manifests itself in periods of atrial tachycardia, flutter, or fibrillation. Cessation of the tachycardia is often followed by long pauses from the SA node. Chronotropic incompetence—condition where the sinus node does not meet metabolic needs by increasing heart rate.

Bradycardia Classifications

Problems with Impulse Conduction Exit Block First Degree AV block Second Degree AV block Mobitz Type 1 – Wenckebach Mobitz Type 2

Third Degree AV block – Complete heart block Bifasicular/Trifasicular block

Second-Degree AV Block – Mobitz II

Regularly dropped ventricular beats 2:1 block (2 P-waves for every 1 QRS complex) Atrial rate = 75 bpm, Ventricular rate = 42 bpm

A “high grade” block, usually an indication for pacing May progress to third-degree, or Complete Heart block (CHB)

Presenter

Presentation Notes

Mobitz Type II second-degree AV block refers to intermittent dropped beats preceded by constant PR intervals. To differentiate Mobitz I from Mobitz II, note the PR interval in the beats preceding and following the dropped beat If a difference between these two PR intervals is more than 0.02 seconds (20 ms), then it is Mobitz I. If the difference is less than 0.02 seconds, then it is Mobitz II. The infranodal (His bundle) tissue is most commonly the site of Mobitz II block. Unlike the graphic, Mobitz II is often accompanied by a wide QRS complex. Note: Advanced second-degree block refers to the block of two or more consecutive P-waves (i.e., 3:1 block).

Third-Degree AV Block COMPLETE HEART BLOCK

No impulse conduction from the atria to the ventricles Atrial rate = 130 bpm, Ventricular rate = 37 bpm Complete A – V disassociation Usually a wide QRS as ventricular rate is idioventricular

Presenter

Presentation Notes

Third-degree AV block is also referred to as complete heart block. Characterized by a complete dissociation between P-waves and QRS complexes. The QRS complexes are not caused by conduction of the P-waves through the AV node to the ventricles. The QRS is initiated at a site below the AV node (such as in the His bundle or the Purkinje fibers). This “escape rhythm” is normally 40–60 bpm if initiated by the His bundle (a junctional rhythm) and <40 bpm if initiated by the Purkinje fibers.

Fascicular Block

Right bundle branch block and left posterior hemiblock

Right bundle branch block and left anterior hemiblock

Complete left bundle branch block

Presenter

Presentation Notes

Bifascicular block is when 2 (with the exception of complete left BBB) of the conduction system pathways below the AV Node are blocked. They are defined as one of the following: Right bundle branch block and left posterior hemiblock Right bundle branch block and left anterior hemiblock - marked by prolonged QRS (> 120 ms or .12 seconds or longer) Complete left bundle branch block

Trifascicular Block

Complete block in the right bundle branch, and

Complete or incomplete block in both divisions of the left bundle branch

Identified by EP Study

Presenter

Presentation Notes

Trifascicular block occurs when 3 of the conduction system pathways are blocked below the AV Node. Trifascicular block can have the appearance of AV nodal block. Combinations that constitute trifascicular block are: Right bundle branch block, complete left anterior fascicular block, and complete left posterior fascicular block Combination of complete block in one or two subdivisions of the common bundle, and incomplete block in one or two subdivisions

Treatment: Pacemakers

Artificial pacemakers: devices that are implanted into the body, just below the collarbone, to take over the job of the heart’s own electrical system and prevent slow heart rates.

Size of a large wristwatch face, contains a computer with memory and electrical circuits, a powerful battery (generator), and special wires called “leads.”

The generator creates electrical impulses that are carried by the leads to the heart muscle, signaling it to pump.

Treatment: Pacemakers Getting a pacemaker does not require open-heart surgery

The pacemaker generator is implanted in a small pocket made under the skin. The leads are usually placed in a vein near the collarbone, and then moved to the heart with the help of an X-ray machine.

The leads touch the heart muscle on one end, and are connected to the pacemaker generator on the other end, programmed to send signals to the heart, and settings can be changed at any time.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiHuNiH-rLZAhVJu1MKHRtzCxAQjRwIBw&url=https://www.webmd.com/heart-disease/video/pacemaker-surgery&psig=AOvVaw1M1BEZ3awWDmk6wraSabnO&ust=1519163177569219

Pacemaker Implantation

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwinzOGV_LLZAhXQqlMKHRVEBzcQjRwIBw&url=http://www.howtopace.com/anchoring-of-leads/&psig=AOvVaw1HrynY4dav2dChjwxoBsIn&ust=1519163759101522

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjdk5ms_LLZAhVK2VMKHcuhBdQQjRwIBw&url=http://www.howtopace.com/attachment-of-device/&psig=AOvVaw1HrynY4dav2dChjwxoBsIn&ust=1519163759101522

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwj5rP23_bLZAhUDt1MKHa04DJIQjRwIBw&url=https://www.youtube.com/watch?v%3DDE2ciEbfGVI&psig=AOvVaw3V4iB5jfsbiUY1Y86WcFlx&ust=1519163896406552

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiltLWT_rLZAhXH2VMKHTDcDc0QjRwIBw&url=http://www.dailymail.co.uk/health/article-3226188/The-time-went-date-passed-Woman-suddenly-faints-claims-s-stopping-finding-love-food-laughter-make-illness-WORSE.html&psig=AOvVaw3oYzy3cPdSth-blUcE4vL9&ust=1519164217661489

Dual Chamber Pacemaker

CRT (Cardiac Resynchronization Therapy)

Torrance Memorial Medical Center participation in Active Quad IDE trial.

Study completed Jan 2018

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjU-sbJ3rLZAhWCoFMKHUg2DdcQjRwIBw&url=https://cardiacrhythmnews.com/ce-mark-medtronic-attain-stability-quad/&psig=AOvVaw2YNbTpItWfoRw9Zwj-3A5t&ust=1519155797062695

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjD4cSB37LZAhWOv1MKHXj0BMoQjRwIBw&url=https://www.researchgate.net/figure/Model-20066-left-ventricular-lead-with-a-close-up-of-the-helix-fixation-mechanism_fig2_275722397&psig=AOvVaw2YNbTpItWfoRw9Zwj-3A5t&ust=1519155797062695

Conduction System

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiAhbub87LZAhVCzFMKHT2_CFgQjRwIBw&url=https://en.wikipedia.org/wiki/Bundle_of_His&psig=AOvVaw18bir_XQ7Ki_c5tdj0-TUw&ust=1519161175176007

His Bundle Pacing

Leadless Pacemakers

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwj6-Iij0rLZAhVJ3FMKHfl-BtcQjRwIBw&url=https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-14/Second-in-a-series-on-leadless-pacing-Leadless-cardiac-pacemakers-what-is-to-be-expected-from-future-developments&psig=AOvVaw3gI_Pw1O83mmCm4SB9Oe4b&ust=1519152494323901

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjR45Ku0rLZAhUEvlMKHXFADJkQjRwIBw&url=https://www.medgadget.com/2015/09/new-wireless-pacemaker-implanted-without-surgery-found-safe-in-clinical-study.html&psig=AOvVaw3gI_Pw1O83mmCm4SB9Oe4b&ust=1519152494323901

Sudden Cardiac Arrest IMPLANTABLE CARDIAC DEFIBRILLATORS Implantable cardiac defibrillators (ICDs)

treat abnormal heart rhythms (ventricular arrhythmias) such as ventricular tachycardia and ventricular fibrillation.

These life-threatening rhythms can cause sudden cardiac arrest (SCA), which results in death if not treated.

98% of people survive a lethal arrhythmia when treated with defibrillation.1 Only 5% of people survive SCA without defibrillation.2

1 Glikson M, Friedman PA. The implantable cardioverter defibrillator. Lancet. April 7, 2001;357(9262):1107-1117. 2 Epstein AE, DiMarco JP, Ellenbogen KA, et al. ACC/AHA/HRS 2008 Guidelines for device-based therapy of cardiac rhythm abnormalities [corrections appear at J Am Coll Cardiol. April 21, 2009; 53(16):1473. J Am Coll Cardiol. January 6, 2009;53(1):147]. J Am Coll Cardiol. May 27, 2008;51(21):e1-62.

Presenter

Presentation Notes

The purpose of an implantable cardiac defibrillator (ICD) is to treat abnormal ventricular heart rhythms such as ventricular tachycardia and ventricular fibrillation. These life-threatening rhythms can cause sudden cardiac arrest (SCA), which results in death if not treated. 98% of people survive a lethal arrhythmia when treated with defibrillation.1 Only 5% of people survive SCA without defibrillation.2

Indications for ICD Implantation

Survivor of sudden cardiac arrest (Secondary Prevention of SCA)

Conditions with high risk for SCA (Primary Prevention of SCA) Congestive Heart Failure, Cardiomyopathy, Previous Heart

Attack, Primary Arrhythmia Disorder, Significant Structural Cardiac Abnormality, etc.

The ICD System

IMPLANTED ICD

• Bradycardia sensing/pacing • Antitachycardia pacing (ATP) • Cardioversion • Defibrillation

VENTRICULAR LEAD

ATRIAL LEAD • Bradycardia sensing/pacing • Antitachycardia pacing

(ATP) • Atrial Arrhythmia

prevention therapies

Presenter

Presentation Notes

Today's dual chamber ICDs can detect and treat bradyarrhythmias, ventricular tachycardia(VT), ventricular fibrillation(VF), as well as some atrial arrhythmias. Therapies for ventricular tachyarrhythmias include: anti-tachycardia pacing (ATP), cardioversion and defibrillation. Treatment for atrial arrhythmias include ATP, and pacing techniques designed to counteract potential atrial arrhythmia initiating mechanisms.

ICD components Overview

BATTERY

CIRCUITRY

CAPACITOR

HEADER

Presenter

Presentation Notes

The internal physical components of an ICD, include the circuitry, battery, and capacitors. The bulk of the device size is due to the capacitors and battery. The container or “can”, shields these components from the body's tissue.

How high voltage is generated

Presenter

Presentation Notes

Medtronic ICDs are comprised of a silver lithium vanadium oxide battery. The normal beginning-of-life voltage of a lithium/silver vanadium oxide battery is approximately 3.2 Volts. The energy used for both pacing and defibrillation comes from the same battery. The ICD uses a transformer to increase or multiply voltage, since a voltage much higher than the 3.2 volt battery is required to terminate a ventricular arrhythmia, such as ventricular fibrillation. The transformer produces up to 800 Volts, and stores this energy in the capacitor. If an arrhythmia is detected and confirmed, the high-voltage capacitors are charged and this energy is delivered to the heart.

Major Functions of an ICD

Sense appropriate cardiac signals

Detect dangerous rhythms reliably

Provide pacing and defibrillation therapy

Store diagnostics

Presenter

Presentation Notes

Now that we have reviewed all the components of an ICD system, what are the major functions of an ICD? All ICDs must be able to sense cardiac rhythms, detect arrhythmias reliably, and deliver therapy, including pacing when necessary. Let’s begin by examining the sensing functions of an ICD.

ICD Defibrillation

Subcutaneous ICD

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiJhuaA_7LZAhXFzlMKHe8cBXIQjRwIBw&url=https://www.dicardiology.com/article/positive-long-term-outcomes-s-icd-system-effortless-study&psig=AOvVaw0X57aluA42VQqFFIVkv_56&ust=1519164511680063

ILR (Implantable Loop Recorder) Cardiac Monitoring Indications for use

The Insertable Cardiac Monitor (ICM) is an implantable patient-activated and automatically-activated monitoring system that records subcutaneous ECG and is indicated in the following cases: Patients with clinical syndromes or situations at

increased risk of cardiac arrhythmias. Patients who experience transient symptoms such as

dizziness, palpitation, syncope, and chest pain, that may suggest a cardiac arrhythmia.

Patient Assistant One-button symptom marking

Insertion Tools Minimally invasive procedure

SOLUTION ENABLERS

CareLink™ Network and Reports

MyCareLink™ Patient Monitor

Reveal LINQ ™ ICM

Reveal LINQ™ Insertable Cardiac Monitoring System

AN ADVANCED MONITORING SOLUTION

THE REVEAL LINQ ADVANTAGE SIMPLE INSERTION PROCEDURE

Presenter

Presentation Notes

4. Reveal LINQ Usability Study. Medtronic data on file. 2013.

Conclusions Multiple Indications for Cardiac Implantable Electronic

Devices Therapeutic and Diagnostic Purposes

Pacemakers (for slow heartrates/bradycardia) Single, dual, leadless, His Bundle, CRT devices

Defibrillators (for treatment/prevention of SCA) With or without pacing, CRT capacity.

Loop Recorders (for arrhythmia monitoring)

Thank you Questions?

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