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HEART DISORDERS
• Blood Vessels– Arteriosclerosis– Atherosclerosis
• Arrythmias• Structural Defects
– Valve damage– Congenital
• Infections• Congestive Heart Failure
Arteriosclerosis
• All types of arterial damage
• But most often used to describe degenerative changes: wall thickening, hardening & loss of elasticity
• Such as, in diabetics or just older individuals
Atherosclerosis
• Atheroma = plaque: what are the constituents?
• Lipids, cells, fibrin & cell debris, often with thrombi attached
• Describe the steps in plaque formation
What happens to blood delivery?
• Tissues, e.g. cardiac not enough oxygen
• If the passage is blocked by ½, the amount of blood delivered is reduced to 1/4th.
• Because the area is proportional to the square of the diameter
Area of a Vessel
• If 4 cars can fit through and the diameter is doubled again, how many cars can pass through?
• 2, 4, 8, 16??
HEART DISORDERS
• Blood Vessels– Arteriosclerosis– Atherosclerosis
• Arrythmias• Structural Defects
– Valve damage– Congenital
• Infections• Congestive Heart Failure
ARRYTHMIASEctopic Beats and Reentry
Sinus Node Abnormalities
Conduction AbnormalitiesAtrial
Ventricular
AV node
Page 281
Name some causes of dysrhythmic function
• Scar tissue in myocardium
• Electrolyte imbalance, e.g. potassium
• Infections or fever
• Hormonal imbalances
• Drug toxicity
• Heart failure
Sinus Node Abnormalities
• Normal Rate: about 70 bpm
• Bradycardia: less than 60– Causes?
• Tachycardia: 100 – 160– Causes?
• Sick Sinus Syndrome
Atrial Conduction Abnormalities
• Premature Atrial Contractions, PAC– Ectopic– Re-entry– Palpitations, rapid or irregular
• Causes?
• Flutter: more than 160• Fibrillation: more than 350
• Effects of Atrial Rhythm Changes
Ventricular Conduction Abnormalities
• PVCs– Can they be serious
• Tachycardia– effects
• Fibrillation, uncoordinated quivering– effects
Heart Block
• Where is it?
• First Degree– increases PR
• Second Degree – periodic missed ventricular beats
• Third Degree, total– How do ventricles continue to contract?
HEART DISORDERS
• Blood Vessels– Arteriosclerosis– Atherosclerosis
• Arrythmias• Structural Defects page 290
– Valve damage– Congenital
• Infections• Congestive Heart Failure
Valve Defects
• Where does blood “traffic” get backed up– Stenosis?– Incompetence?
• Back-up effect the sameMitral valve?
Aortic valve?
Effects of Valve Damage
• Arrythmias
• Enlarged Heart
• Poor circulation
• Susceptible to Infective Endocarditis
Infective Endocarditis
• Subacute, low virulence– Strep viridans
• Acute, high virulence– Staph aureus
• Causes
• Effects– Vegetations and progressive valve damage– Emboli
Forgot to mention
• Acute Rheumatic Fever– Another after-effect, nervous system
– Causes tics, arm lunges, facial grimaces,etc.– Called Sydenham’s chorea or St. Vitus dance
Congenital Heart Defects
CHF
Blood Vessels
Hypertension
Shock
Peripheral Vascular Diseases
Finish Ch. 18
Congenital Heart Defectspage 288
• Septal Defects
• Dislocations• Valve Defects, already covered
• Tetralogy of Fallot
Blood Flowthrough septal defects
May also be called shunts
1. Direction of flow? – why?
2. Cyanotic? – Or Acyanotic?
3. Reduced Blood Volume in Circulation?
Symptoms
• Fatigue• Sleep Difficulties• Feeding Difficulties• Irritability• Squatting Posture• Rapid Heart Beat
• Eventual CHF possible
Pericarditispage 294
• Pericardium, two layers
• Inflammation– swelling– exudate
• Effects– Cardiac tamponade– Adhesions
• Causes
Congestive Heart FailurePp 284 – 288
• What is it?
• Causes?
• Left-sided – why?
• Right-sided – why?– If due to pulmonary disease, called Cor
Pulmonale
Note
We will not require learning the compensation mechanisms on
p. 285. They are very interesting but too complex for our needs in
this course.
Effects of CHF
Forward
Backup
Left-sided Right-sided
Define: dyspnea, orthopnea, paroxysmal nocturnal dyspnea
See Table 18-2 on p. 285
Vasculature
Pp 265 - 269• Arteries • Arterioles
• Capillaries called microcirculation
• Venules• Veins
Vasculature
• Arteries and Veins
• Walls are made up of three layersTunica: intima
media smooth muscle
adventitia elastic and collagen fibers
Veins have thinner walls, less muscle
Veins
• Capacitance Vessels
• Thinner walls & less muscle than arteries
• Blood flow by skeletal muscle, respiratory movements and gravity
• Valves
Vasa vasorum
Tiny blood vessels in the walls of arteries & veins
Supply oxygen to the tissues that make up the walls
Controls
• Autoregulation in arterioles– Conditions?
• SNS, normal constriction
• Norepinephrine, epinephrine, angiotensinincrease constriction
• Precapillary Sphincters
Controls
• How does body sense bp?
• Sympathetic
• Parasympathetic?
• Hormones: ADH, aldosterone
• Renin-angiotensin-aldosterone
Hypertension
Pp 295 - 297
• 140/90
• Primary, Secondary, Malignant
• Systolic or Diastolic– Elderly, high systolic and low diastolic
Physical Causes
• Blockages and loss of flexibility
• Vasoconstriction– Over-responsive to stimuli– Increased stimulation
• Hormones, stress• Renin-angiotensin, aldosterone cycle
• Hypervolemia
Who is most susceptible• Men more than women until middle age
• Elderly
• African descendants more than caucasians
• Familial predisposition
• Behaviors or personality types
Principal Dangers
• Can be silent• Treatment & lifestyle changes may not be
consistently maintained
• Stroke• Myocardial Infarction• Long-term damage,e.g. kidney• Aneurysms
Shock
Pp 301 - 305• What is it?
• How does it cause its major effects?
• Types– Hypovolemic– Cardiogenic– Changes in peripheral resistance
Signs
• Thirst• Agitation• Tachycardia• Pale, cool, moist skin
• Or with septic shock may have fever
• Lethargy, dizziness
Treatment
• Treat the primary problemvasoconstrictors, epinephrine, antimicrobials,
Glucocorticoids
• Lie down, cover, keep warm
• Supply oxygen
Omit next 2 slides
Effects and compensations of shock are important but complex
Just know that the effects of shock are serious
(you do not need all the detail on pp 302 & 303)
• And they progress rapidly
• And they can cause multiple organ failure
• And death
Strokes
• What? Compare to MI
factors will be similar
• Causes– Atheroma, embolus, hemorrhage
• Causes of hemorrhage– Hypertension, aneurysm
• Damage related to cause
Peripheral Vascular Diseases
• Aneurysms
• Thromboses
• Peripheral Atherosclerosis
• Raynaud’s Syndrome
• Buerger’s Disease
• Varicose Veins