Mod V: Cardovascular Implantable Electronic Devices (CIED) Flashcards Preview

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Flashcards in Mod V: Cardovascular Implantable Electronic Devices (CIED) Deck (76)
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1

Cardovascular Implantable Electronic Devices (CIED)

Cardovascular Implantable Electronic Devices (CIED) are used for the Treatment & management of:

Cardiac conduction & Arrhythmia problems

Symptomatic bradycardia

(including that resulting from sinus node dysfunction)

Atrioventricular (AV) conduction block 

(after catheter ablation of the AV node or junction)

2

Perioperative mgnt of patients with Cardovascular Implantable Electronic Devices (CIED)

Pacing can be provided in several ways, including

Application of external pacing pads

Urgent insertion of a transvenous pacing lead via central venous access

Implantation of permanent intracardiac leads along with a pulse generator.

Regardless of how it is provided, pacemaker programming (and therefore pacemaker function) must always be individualized to the needs of the individual patient

3

Perioperative mgnt of patients with Cardovascular Implantable Electronic Devices (CIED)

The ‘best’ perioperative care of a patient with a CIED usually comes from the recommendations from which individual or team?

The physician/care team who usually monitor/manage the CIED (the CIED ‘team’)

Such recommendations should routinely be sought in advance whenever feasible. 

4

Perioperative mgnt of patients with Cardovascular Implantable Electronic Devices (CIED)

Electronic device that delivers electrical stimulation to heart

Cardovascular Implantable Electronic Devices (CIED)

 

 

5

Perioperative mgnt of patients with Cardovascular Implantable Electronic Devices (CIED)

Pacing can be delivered to

a single chamber (atrium or ventricle only),

dual chambers (atrium and ventricle), or

multiple chambers (in biventricular pacing)

6

Perioperative mgnt of patients with Cardovascular Implantable Electronic Devices (CIED)

Leads - Pacing can use either:

 

unipolar or bipolar leads.

Over the last 15 yr, bipolar leads have been predominantly used. With a bipolar lead, both the cathode and anode are present on the lead itself and thus the distance between them is much smaller than with a unipolar lead (where the pulse generator functions as the anode). The advantage of the bipolar configuration is reduced susceptibility to electromagnetic interference (EMI).

7

Cardovascular Implantable Electronic Devices (CIED)

How do Cardovascular Implantable Electronic Devices (CIED) function?

Sensing intrinsic cardiac electrical potentials

device can sense intrinsic electrical activity in the chamber where the lead is placed to either inhibit or trigger pacing in that chamber

If no spontaneous depolarization of the chamber is sensed within the programmed limits, the device will deliver a pacing stimulus

 If a spontaneous chamber depolarization occurs and is sensed, the device will inhibit the delivery of a pacing stimulus and wait for a subsequent depolarization during the next pre-set time interval.

A dual-chamber pacing mode allows for both sensing and subsequent triggering or inhibition of pacing in one or both chambers

8

Implantable Pacemaker System

What are the components of a pacemaking system?

Impulse generator

Leads

(carry the electrical impulse to the patient’s heart)

9

Implantable Pacemaker System

What's the function of PM leads?

Insulated wires tha deliver electrical impulses from the pulse generator to the heart

Leads carry the electrical impulse to the patient’s heart

Transmit electrical signals from the heart to the pulse generator

10

Implantable Pacemaker System

How are PM leads connected to the heart chambers?

Through the vena cava (transvenous leads), or

Sewn onto the surface of the heart (epicardial leads)

11

Implantable Pacemaker System

In terms of polarity what are the different types of PM leads?

Unipolar leads (one electrode per lead)

Because two electrodes are required to complete a circuit, the second electrode in a unipolar configuration is the metal generator case

Use of the case as an electrode requires that the generator pocket be devoid of gas, and electrical continuity has reportedly been disrupted by the use of nitrous oxide​

Bipolar leads (two electrodes per lead), or

Multipolar leads (multiple electrodes and wires contained within one lead with connections in multiple chambers)

Pacemaker leads are generally placed in the right atrial (RA) appendage, right ventricle (RV), or, in a dual-chamber device, both

12

Implantable Pacemaker System

PM leads with pacing polarity are more sensitive to the effects of EMI?

PMs with unipolar leads are more sensitive to the effects of EMI

13

Implantable Pacemaker System

Most pacemaking systems (except older Autocapture devices from St. Jude Medical) pace in which pacing polarity mode? why?

 

Bipolar mode

because bipolar pacing usually requires less energy

14

Implantable Pacemaker System

Which sensing polarity modality is more resistant to interference from muscle artifacts or stray electromagnetic fields

Bipolar sensing

15

Implantable Pacemaker System

What are Indications for permanent pacing?

Sinus node disease

(Symptomatic diseases of impulse formation)

Atrioventricular nodal disease

(Symptomatic diseases of impulse conduction)

Long QT syndrome

Hypertrophic obstructive cardiomyopathy

Dilated cardiomyopathy

16

Implantable Pacemaker System

Where are Implantable Pacemaker System pulse generator usually implanted in the body?

Infraclavicular region

SubCutaneously

 

17

Implantable Pacemaker System

What are the components of Implantable pulse generator of a Implantable Pacemaker System?

Power source

Circuitry

18

Implantable Pacemaker System

How long does the Power source of Implantable pulse generator last?

5 to 15 years

19

Implantable Pacemaker System

What's the function of an Implantable pulse generator circuitry?

---

 

20

Implantable Pacemaker System

What's the function of a pacemaker electrode?

Conductor located at the end of the lead

Delivers the impulse to the heart

 

 

21

Implantable Pacemaker System

How does Myocardial tissue participate in the Implantable Pacemaker System?

Receives electrical impulse from the lead and stimulates the heart

Produces an electrical signal that the lead senses, or “sees

22

Implantable Pacemaker System

Graphical representation of  a modern pacemaker: see picture

Graphical representatio of  a modern pacemaker

Note: Generator, RA an RV leads

Green lead => BiVent PCMkr

23

Implantable Pacemaker System - Important Definitions

The process whereby a pcm spike generates a mechanical contraction (Ppcm spike a/w QRS complex) is known as ?

 

Capture

24

Implantable Pacemaker System - Important Definitions

The process whereby the PCM fails to deliver sufficient energy to the myocardium to produce a depolarization is also known as:

Loss of Capture

The PCM sees other things, fires but does not generate a QRS

The question you must ask is "why?"

 

 

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Implantable Pacemaker System - Important Definitions

What are causes of "Loss of Capture"?

Inappropriate output setting

Increased resistance to conduction

Dislodged/fractured lead

Hypokalemia

Cardiac tissue is refractory /hyperpolarized

Hypokalemia lowers the RMP which pushes the pacing threshold by

Faulty cable connection

26

Implantable Pacemaker System - Important Definitions

Minimum amount of energy required to consistently capture the myocardium and cause depolarization/contraction

 

Pacing Threshold

Measured by amplitude (mA or V) & duration (mS)

27

Implantable Pacemaker System - Factors Affecting Pacemaker Threshold

What are the things you can affect? How can you increase pcm threshold? aka (make it more difficult to pace)

Acidosis - Hyperglycemia - Hyperoxemia

Hypokalemia - Hypernatremia

B-blockers - Procainamide (toxic dose) - Mineralocorticoids

Myocardial scar tissue

28

Implantable Pacemaker System - Factors Affecting Pacemaker Threshold

What are the things you can affect? How can you decrease pcm threshold? aka (make it easier to pace)

Stress - Hypoxemia - Hyperkalemia

Ephedrine - Glucocorticoids

29

Implantable Pacemaker System - Important Definitions

undersensing (intrinsic activity is not detected)

Undersensing

Cuases over pacing – sense activity and tries to oeverpace… why?

30

Implantable Pacemaker System - Important Definitions

Causes of Undersensing - senses activity and tries to oeverpace… why?

 

Battery depletion

Decreased QRS voltage

Fusion beat

Dislodged/fractured lead

Inappropriate sensitivity setting

Myocardial infarction