UNDERSTANDING

HEART

ARRHYTHMIAS

UNDERSTANDING HEART ARRHYTHMIAS

ANATOMY OF THE HEART

The heart is a muscular organ that contracts to pump

blood through the blood vessels to all parts of the body.

It is made up of four chambers:

The Atria – These two upper chambers receive blood

returning to the heart.

The Ventricles – These two lower chambers are more

muscular and responsible for pumping blood out of the heart.

The heart tissue receives oxygen and nutrients from blood

supplied by the coronary arteries. These arteries branch off the

aorta and travel downward along the muscular wall of the

heart.

An electrical conduction system in the heart tissue controls

rhythmic beating of the heart.

ANATOMY OF THE HEART

CONDUCTION SYSTEM OF THE HEART

Imbedded into the tissue of the heart is a

specialized conduction system that insures these chambers

contract in the correct order, atria first, ventricles second. This

rhythmic contraction is vital throughout life to maintain the

proper flow of blood to the body.

The sinoatrial (SA) node is called the pacemaker of the

heart. It is the first structure of the conduction system and is

found in the right atrium. From the SA node, the stimulating

impulse passes through the atrial muscles, causing them to

contract.

The atrioventricular(AV) node is in the floor of the right

atrium. It receives the impulse from the SA node and passes it

into the ventricles: first through the AV bundle (bundle of

His), and then the impulse travels down the interventricular

septum on the bundle branches.

Purkinje fibers, arising from the AV bundles, turn upward

and spread throughout the ventricular walls, causing the

ventricle muscle fibers to contract last.

CARDIAC CONDUCTION SYSTEM

DIAGNOSIS EKG

An electrocardiogram (EKG) records how well the conduction

system of the heart is working. The peaks and valleys of the

EKG wave correspond to the electrical impulse travelling

through the heart muscle.

If one area of the conduction system is damaged, then the

EKG wave will be abnormal and the exact type of

abnormality tells the physician where the damage has

occurred.

The irregular heart beat caused by conduction system

problems is called an arrhythmia. There are many different

arrhythmias and most are not dangerous. However, others are

life – threatening and require immediate medical attention.

EKG

BRADYCARDIA

Bradycardia is an abnormally slow heartbeat. The prefix

“brady” means slow. In adults this is a resting heart rate of

fewer than 60 beats per minute. The exception is aerobically

fit persons; they normally have a slower heart rate because

their strong hearts pump more blood per hearbeat.

CAUSES

Bradycardia results from a malfunction or disruption in the

passage of the electrical impulses in the heart. A

malfunctioning sinoatrial node (SA node) is the most common

cause of bradycardia.

In other instances, the impulse passing through the

atrioventricular node (AV node) may not travel through the

heart effectively, causing fewer heartbeats per minute.

Other causes of Bradycardia may include heart tissue damage

from a heart attack, chemical imbalances like low potassium,

or medications.

Some older persons develop this condition as a result of

aging, rather than from a disease or condition.

BRADYCARDIA

SYMPTOMS

If the heart beats too slowly, then not enough

blood will reach the brain and muscles. The person will feel:

Fatigued and lethargic

Faint

Dizzy or light - headed

ATRIAL FIBRILLATION

Atrial fibrillation (Afib) is a non- life threatening

condition that affects millions of people. The atrium of the

heart contracts irregularly and rapidly. The result is a less

efficient heart pump. More severe heart health issues may

occur overtime if the problem is not managed or corrected.

COMMON SYMPTOMS

Rapid heart beat

Dizziness

Sweating

Chest pain or pressure

Shortness of breath

Fainting and tiring easily when exercising

ATRIAL FIBRILLATION

VENTRICULAR FIBRILLATION

Ventricular fibrillation (V-fib) is a sudden life-

threatening condition where the electrical impulse in the heart

is so disorganized that the ventricles stop contracting

rhythmically. The heart stops pumping blood and a sudden

cardiac arrest occurs. The heart stops pumping blood and a

sudden cardiac arrest occurs. Immediate medical treatment

with a defibrillator is required to correct rhythm.

An external or implantable defibrillator delivers an

electrical impulse to the heart, allowing the heart’s normal

electrical system to restart in an attempt to restore normal

sinus rhythm.

VENTRICULAR FIBRILLATION

IMPLANTABLE PACEMAKERS AND

DEFIBRILLATORS

Implantable cardiac devices, such as pacemakers

and defibrillators, are used to maintain a normal rhythm in the

heart. They consist of an electronic chip called the pulse

generator, which generates an electrical impulse to stimulate

the heart.

Wires from the pulse generator are threaded

through blood vessels to electrodes implanted in the heart is

beating and send a stimulus to maintain or correct the heart

rhythm.

PACEMAKER IN BODY

Implantable pacemaker device (IPD):

A pacemaker maintains a normal rhythm by

sensing the beat of the heart. If the heart is beating too slowly,

a pacemaker can send stimulus to the heart to maintain a

normal heart rhythm speed.

An implantable cardioverter defibrillator (ICD):

An ICD is able to sense life-threatening irregular

heartbeats like ventricular fibrillation. It can then deliver either

a low-energy or high-energy electrical impulse that shocks the

heart muscle and causes it to return to its normal rhythm.

PACEMAKER MACHINE

TIPS FOR A HEALTHY HEART

Do not smoke and Manage stress in your life.

Keep physically active so your heart muscle will be strong.

Eat a heart – healthy diet that is low in sodium, fat and

cholesterol.

Exercise to maintain a healthy body weight.

Aim to have regular good night’s rest.

Have your blood pressure checked regularly.

THANK YOU