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