Download Pathological Conditions: The Heart and Blood Vessels

Pathological Conditions: The Heart and
Blood Vessels
Medical Terminology
Arrhythmias: Abnormal heart rhythms
Types of arrhythmias:
1.Heart block or atrioventricular
block:
* Failure of proper conduction of
impulses through the AV node to the
Bundle of His.
 Damage to SA node can cause
impulses to be too weak to activate
AV node which means that
impulses fail to reach ventricles
 If failure occurs only occasionally
causing heart to miss beat at
regular intervals – partial heart
block
 No impulses reach AV node from
SA node means ventricles contract
slower than the atria and are not
coordinated – complete heart
block
 RX: cardiac pacemaker –
establish normal rhythm.
2.Flutter
 Rapid but regular contractions of
atria or ventricles
 Heart rhythm may reach up to 300
beats per minute (BPM)
3.Fibrillation
 Rapid, random, ineffectual, and
irregular contractions of the heart;
350 bpm or more
 Atrial fibrillation: wave of
excitation passes through atrial
myocardium more quickly than in
atrial flutter.
 Defibrillator is used to reverse
abnormal rhythm; aka
cardioversion
 Automatic Implantable
Cardioverter/Defibrillator (AICD)
– implanted into chest wall to sense
arrhythmias and correct them
 Radiofrequency catheter ablation
(RFA): nonsurgical treatment
used to treat arrhythmias; catheter
placed in blood vessels leading up
against heart muscle , delivers a
high-frequency current to burn a
small portion of muscle, aka
ablation
4.Cardiac Arrest
 Sudden and often unexpected
stoppage of heart movement
5.Palpitations
 Uncomfortable sensations in chest
associated with different types of
arrhythmias
 Not necessarily indicate of a
serious condition.
 Two causes: premature
ventricular contractions (PVCs),
premature atrial contractions
(PACs)
Congenital Heart Disease: Abnormalities
in heart at birth
1.Coarctation of the aorta (CoA) –
Narrowing (coarctation) of aorta
2.Patent Ductus Arteriosus (PDA) –
Small duct between aorta and
pulmonary artery which normally
closes soon after birth, remains open
 Oxygenated blood flows from
aorta to pulmonary artery
3.Septal Defects – Small holes in
septum between atria (atrial septal
defects ASDs), or ventricles
(ventricular septal defects VSDs)
 Many septal defects will close
spontaneously and others will
require surgery
4.Tetralogy of Fallot – Congenital
malformation of heart involving
four distinct defects as follows:
 Pulmonary artery stenosis – Blood
is not adequately passed to lungs
for oxygenation
 Ventricular Septal Defect – Gap in
septum allows deoxygenated blood
to pass info left ventricle and from
there to aorta
 Shift of aorta to right – oxygenpoor blood passes more easily
from right ventricle to aorta
 Hypertrophy of right ventricle –
myocardium works harder to
pump blood through narrowed
pulmonary artery
Congestive Heart Failure: Heart is
unable to pump its required amount of
blood as more blood enters heart from
veins than leaves through arteries
Coronary Artery Disease: Dz of arteries
surrounding the heart
 Three large vessels that arise from
aorta and supply oxygenated blood to
heart
 Atherosclerosis: deposition of fatty
compounds on inner lining of coronary
arteries
 Narrowing causes inflexibility and
plugging up of vessel; roughened lining
of artery may rupture or cause
thrombotic occlusion
 Blood flow decreased = ischemia
leading to necrosis; Area of dead
myocardial tissue is infarction
 Angina pectoris – temporary difference
between supply and demand of oxygen
to heart muscle
 Rx – CABG
 Percutaneous transluminal coronary
angioplasty (PTCA) – catheterization
with balloons and stents
 Transmyocardial laser
revascularization (TMLR) – laser
makes holes in heart muscle to induce
growth of new blood vessels
Endocarditis – Inflammation of inner lining of
heart caused by bacteria; Rx. with antibiotics
Hypertensive Heart Disease – High blood
pressure affecting the heart
 Caused by contraction of arterioles
leading to increased pressure in
arteries
 Heart has to pump more vigorously to
overcome increased resistance in
arteries
 Vessels lose elasticity, become like solid
pipes and place increased burden on
heart to pump blood through body
Mitral Valve Prolapse (MVP) – Improper
closure of mitral valve when heart is pumping
blood
*Antibiotics are given at time of dental
procedures to prevent valve from becoming
infected.
Murmur – extra heart sound heard between
normal beats
Pericarditis – Inflammation of membrane
surrounding heart
 Caused by virus, bacteria, or idiopathic
 May need pericardiocentesis to remove
excess fluid
Rheumatic Heart Disease – Heart disease
caused by rheumatic fever
 Rheumatic fever – occurs usually in
childhood, can follow a few weeks after
a streptococcal infection
 Damages heart valves (esp. mitral
valve); become inflamed and scarred
BLOOD VESSELS
Aneurysm – Ballooning out of artery caused
by weakness in arterial wall or breakdown of
wall due to atherosclerosis
 Danger is rupture
 Rx. Depends on location of vessel
 Small vessels in brain – occlusion of
vessel with small clips
 Larger arteries – resection of vessel
with synthetic graft
Peripheral vascular disease – blockage of
blood vessels in lower extremities due to
atherosclerosis
 Arteries in groin or upper leg narrow
or become blocked, blood flow to lower
leg and foot is reduced
Raynaud Phenomenon – Short episodes of
pallor and numbness in fingers and toes due
to temporary constriction of arterioles in skin
 Idiopathic but may be secondary to
cold temperatures, emotional stress, or
cigarette smoking
Varicose Veins – Abnormally swollen and
twisted veins, usually occurring in legs
 Due to damaged valves that fail to
prevent backflow of blood