CMU Basics

Welcome to
Monitor Tech

Course

The Basics

Kali Minier, MSN, RN, CEN
Modified for use in Monitor Tech Class by Kate Dodge, BSN, RN
Updated by Heather Blake BSN, RN, CV-BC

In this presentation we will review the

following topics:

1. Cardiac anatomy and physiology
2. Electrical pathways of the heart

3. Blood flow through the heart

4. Basic cardiac vocabulary
5. Landmarks & ECG basics

Click on the hearts to access
different videos!

CARDIAC
ANATOMY

AND

PHYSIOLOGY

01

The heart sends
blood around your
body. The blood
provides your
body with the
oxygen and
nutrients it needs.
Without blood
flow, cells die.

Circulation

The Structural Anatomy of the Heart

•There are 4 chambers of the heart

•There are 4 valves of the heart

•The heart is divided in half by a muscular
wall called the septum.

•The goal of the heart is to pump oxygenated
blood to the entire body.

Pericardium

The pericardium acts
as mechanical
protection for the heart
and big vessels, and a
lubrication to reduce
friction between the
heart and the
surrounding
structures.

Tissue
Layers

3 layers of

tissue make up
the wall of the

heart:

endocardium,
myocardium
(the muscle),

epicardium

FADavisreader.vitalsource.com, retrieved
12/27/22

Map of the External Anatomy of the Heart

Map of the Internal Anatomy of the Heart

Heart
Valves

Heart Valves

BLOOD FLOW

THROUGH
THE HEART

02

Blood
Flow
Through
the
Heart

The Cardiac

Cycle

1.

Atrial and Ventricular
diastole

2.

Atrial systole

3.

Ventricular systole

ELECTRICAL
PATHWAYS &
ACTIVITY OF
THE HEART

03

Intro to the Cardiac Conduction System

✔
Cardiac muscle contraction begins with electrical
excitation/stimulus of the myocardial fiber

✔
Source of electricity is flow of charged ions- Na+, K+, & Ca++ -
across the cardiac cell membrane

✔
Movement of charged ions down cell: ACTION POTENTIAL

Building Blocks

Impulse Conduction

●Caused by an electrical current

●Membrane potential: When ions with opposite electrical
charges are separated by a membrane

●Polarization: When a membrane has an excess of positive
ions on one side and an excess of negative ions on the
other

Impulse Conduction: Step 1 Resting

Potential

Impulse Conduction: Step 2

Depolarization

Impulse Conduction: Step 3

Action Potential

Impulse Conduction: Step 4

Repolarization

Impulse Conduction: Step 5 Refractory

Period

Cardiac action
potential

●Action potential allows
for Ca++ influx into the
cell.

●Additional Ca++ released
from Sarcoplasmic
Reticulum.

●Ca++ sustains
depolarization.

●Ca++ binds to Troponin.

●Myosin and actin forms
cross-bridge.

●Contraction occurs.

Your heart's electrical system is

made up of three main parts:

1.

The sinoatrial (SA) node, located in
the right atrium of your heart.

2.

The atrioventricular (AV) node,
located on the interatrial septum
close to the tricuspid valve.

3.

The His-Purkinje system, located
along the walls of your heart's
ventricles.

Electrical System of the Heart

https://youtu.be/TnFoJ7Hhi-M

BASIC CARDIAC
VOCABULARY

04

1.
Automaticity – the ability of heart cells to spontaneously depolarize
and generate an action potential

2.
Action Potential – the change in electrical potential associated with the
passage of an impulse along the membrane of a nerve or muscle cell

3.
Contractility – the ability of muscle tissue to contract

4.
Diastole – the period between contractions or the resting period of the
heart when the ventricles are filling or dilating

5.
Systole – the contraction of the heart

Basic Cardiac Vocabulary

LANDMARKS &

ECG BASICS

05

The 5 Lead

The Graph Paper

The Graph Paper

The Complex

Parts of an ECG Complex

37

Click on the complex to
learn about each
segment!

P Wave

R Wave

PR Interval

S Wave

QRS Complex

T Wave

P-R interval=0.12 - 0.20 sec (3 - 5 small boxes)

QRS width = 0.08 - 0.12 sec (2 - 3 small boxes)

Q-T interval=0.35 - 0.43 sec

R-R=Should be equal distance apart

Quick Review

Pulling it all Together

https://youtu.be/lRHq7sMRWpU

Follow the 5 Steps

Rule 1

Normal Sinus Rhythm

Rule 2

Sinus Bradycardia

Sinus Tachycardia

Rule 3

Sinus Arrhythmia

Rule 4

Rule 5

Let’s try some
practice strips!