Intro to cardiovascular Physiology and Pathology; CAD and MI

Exam 2

1

vena cava

2

right atrium

3

tricuspid valve

4

right ventricle

5

pulmonary semilunar valve

6

pulmonary artery

1

pulmonary vein

2

left atrium

3

bicuspid valve

4

left ventricle

5

aortic valve

6

aorta

lungs

where does blood go after it leaves the pulmonary arteries?

the body

where does blood go after it leaves the aorta?

cardiac output

the amount of blood leaving the heart

HR and SV

cardiac output is determined by _____

stroke volume

volume of blood in the left ventricle being ejected by each heartbeat

blood pressure

determined by the cardiac output and vascular resistance

vascular resistance

amount of resistance in the vascular walls

vascular resistance; blood flow

_____ must be overcome to push blood through the circulatory system and create _____

decrease

as we age there is a ____ in cardiovascular capacity

relationship between cardiovascular capacity and age

a loss of muscle mass, decreased elasticity of blood vessels, reduced lung function and accumulation of plaque

chronic pathology on cardiovascular capacity

Accumulation of risk factors, such as obesity, low physical activity, smoking, drug use, or alcohol

Lead to cellular adaptation (ex. ventricular hypertrophy)

acute pathology on cardiovascular capacity

Pathogens, trauma, and acute renal failure

leads to cellular necrosis
 (example – ischemia (MI))

physical reserve

the distance between an individual’s capacity and metabolic cost of an activity

less reserve

the ____ the harder and more taxing a task will be for a person

signs and symptoms of cardiovascular pathology

•Pain

•Palpitations

•Fatigue

•Syncope – dizzy or lightheaded

•Cough – or shortness of breath

•Cyanosis

•Peripheral edema

•Claudication

angina

pain associated with cardiovascular pathology classified by pressure, tightness, squeezing, and heaviness in the chest, neck, jaw, shoulder, or arm

greater; below

Angina occurs when the demand for oxygen is ___ than the supply. it is commonly seen when a person’s capacity is at or ___ the tast cost

60-100

normal resting heart rate

bradycardia

slow heart rate

tachycardia

fast heart rate

relationship between angina and the supply and demand of oxygen to the heart (or skeletal muscle for claudication).

an imbalance between oxygen supply and demand in the heart muscle. Inadequate oxygen supply to the heart muscle during periods of increased demands leads to myocardial ischemia and chest pain.

pulmonary edema

occurs when there is an abnormal accumulation of fluid in the lungs; occurs due to increased pressure in the blood vessels of the lungs or damage to the lung tissue. This can be caused by heart failure, MI, or hypertension.

peripheral edema

  Accumulation of fluids in tissues, typically in lower extremities like the legs, ankles and feet;Occurs due to increased pressure within the veins and capillaries of the lower extremities. This increased pressure can be caused by heart failure, venous insufficiency, live/kidney disease

Hormone Replacement Therapy

_______has not been shown to provide “cardio-protective” benefits. 

Oral contraceptives

_________ may increase the risk of blood clots and subsequent MI/stroke. This is especially true in women over 35 who are smokers.

Disease independent age related changes to cardiovascular system

o   Reduced # of cardiac myocytes, and cells within the conduction system 

o   Development of cardiac fibrosis

o   Reduced calcium transport across the membrane

o   Reduced capillary density

o   Reduced responsiveness to beta-adrenergic stimulation

o   Impaired autonomic reflex control of HR

o   Thickening of the left ventricular wall (“especially in the face of underlying hypertension”)

o   stiffening/calcification of the ventricles, valves, and arteries

o   Increased likelihood of clinically significant atherosclerosis heart disease

Collectively age related changes to cardiovascular system

Decrease in maximal HR

Decrease in cardiac output

Decrease in VO2max

Increase in the incidence of arrhythmia's

cardiovascular changes and disease risk for men

o   increased incidence of Mitral Valve Prolapse (MVP);not getting good closure of the mitral valve

o   Increase in left ventricular mass with aging

o   Increased risk of dangerous arrhythmias

o   Decreased responsiveness to anticoagulants and thrombolytics, but a higher incidence of bleeding

cardiovascular changes and disease risk for women

o   Risk for cardiovascular disease (CAD specifically) increased sharply after menopause

o   May experience angina in the mid-scapular region of the back

o   Hormonal Influences

Hormonal influences for women with cardiovascular changes and disease risk

Estrogen appears to be “cardio-protective”

Increased HDL levels (“good cholesterol”)

Reduces clotting risks

Both estrogen and estradiol have a dilating effect on the blood vessels, helps maintain normal BP and blood flow

  Oral contraceptives may increase the risk of blood clots and subsequent MI/stroke. Especially for women over 35 who are smokers

Response to injury theory

Explains the atherosclerotic disease, including coronary artery disease (CAD) and cerebrovascular disease (CVD)

proposes that atherosclerosis develops in response to endothelial injury, initiating a cascade of inflammatory and cellular processes that lead to the formation of plaque within the arterial walls

Non-modifiable risk factors for CAD

o   Age (83% of deaths from CAD occur in individuals > 65 y/o)

o   Gender (males are at a greater risk, especially when compared to pre-menopausal women)

o   Genetics (a family history of premature heart disease is associated with elevated risk)

modifiable risk factors for CAD

o   HTN- Hypertension (SBP > 130 or DBP > 80 mmHg)*

o   Cholesterol ((Total chol. > 200 mg/dl)

o   Smoking (there is no safe amount)

o   Inactivity (increases risk for many chronic disease conditions including heart disease)

o   Obesity (BMI > 30 kg/m2)

o   Diabetes (fasting glucose level > 126 mg/dl)

o   Stress

less than 120/80

What is normal blood pressure

greater than 140/90

what is considered high blood pressure

under 100

normal LDL value

60 and higher

normal HDL value

under 200

normal total cholesterol value

99 mg/dl or below

normal fasting glucose value

18.5-25

Normal BMI value

25-30

overweight BMI value

30-35

obese class 1 BMI value

Metabolic syndrome

Cluster of risk factors in a single individual

Three or more of the following:

o   Waist > 35” in women, > 40” in men

o   Triglyceride levels > 150 mg/dl

o   HDL < 50 mg/dl in women,
< 40 mg/dl in men

o   BP > 130/85 mmHg

o   Blood sugar > 100 mg/dl

Stable Angina

o   Predictably induced with a given level of exertion

o   Treat with rest and/or medications

o   Monitored exercise is safe

Unstable angina

  may or may not be brought on by exertion. 

Characterized by increasing frequency, duration, and intensity of ischemia, and/or a reduced “ischemic threshold”.

Physical activity

______ is contradicted with un stable angina

Common changes on an EKG with myocardial ischemia

presence of T wave or an ST segment depression

Cardiac angioplasty (coronary angiography)

Invasive procedure that allows visualization of the coronary arteries and identification of obstructive lesions

Catheter access may be from groin, arm, or neck. A dye is injected that allows for visualization of the coronary arteries using “fluoroscopy”

Stent can be placed to reopen arteries

Catheter; “fluoroscopy”

During Cardiac angioplasty (coronary angiography), ____ access may be from groin, arm, or neck. A dye is injected that allows for visualization of the coronary arteries using ______

Stent; reopen

A ____can be placed to ____ arteries in cardiac catheterization angioplasty procedures.

Most common coronal arteries for occulsion

Left anterior descending a. (most common)

Left circumflex a.

Right circumflex a.

“Open Heart Surgery”, in which vessels are harvested and used to bypass occlusion

what happens when a CABG procedure is done? 

commonly used bypass vessels in open heart surgery

Internal Mammary (preferred for LAD occlusion)

Radial artery

Saphenous Vein (associated with chronic pain post-surgery and with physical activity)

Sternotomy

the sternum is separated to allow access to the heart, the sternum is wired closed post-opperatively

Sternal precautions

·       No lifting, pulling, pushing (10 lb limit) for 6 weeks

·       Log roll technique in/out bed

·       No driving (4-8 weeks)

·       ROM exercise - neck, shoulders, torso ("caution with sternectomy")

·       Scar mobilization when incision is healed

·       Be conservative if: osteoporosis, diabetes, advanced age

Acute myocardial infarction

Permanent damage (“necrosis”) to myocardial due to interrupted blood flow 

Ischemia is often a precipitating factor. Typically, the result of significant CAD that culminates in a complete blockage

Often fatal, the mortality rate for AMI is approximately 30%

Types of acute myocardial infarction

transmural

subendocardial

Myocardial ischemia

when blood flow to the myocardium is obstructed by a partial/complete blockage of a coronary artery by a buildup of plaque (atherosclerosis). If the plaques occur, ___will occur

transmural

refers to full thickness

subendocardial

refers to partial thickness

ST Elevation Myocardial Infarction (STEMI)

transmural- full thickness

account for 70% of AMI

Non ST Elevation Myocardial Infarction (NonSTEMI)

Subendocardial- partial thickness

MI that does not demonstrate ST segment elevation on the EKG

Common complications following myocardial infarction

Dysrhythmias (Commotio Cordis)

Heart Failure

Mural Thrombus

Ventricular Aneurysm

Ventricular rupture with tamponade

Commotio Cordis

• Dysrhythmias

• Blunt force trauma to the pre-cordial chest region occurring during the early ventricular repolarization period triggering an arrhythmia

• Sudden Cardiac Death

Phase I of Cardiac Rehabiliation

Inpatient phase: (typically 3-7 days)

Review sternal precautions if post-CABG

Initiate physical activity and provide home exercise/activity guidelines.

Refer to comprehensive out-patient cardiac rehabilitation program

Phase II of Cardiac Rehabiliation

Acute outpatient: (may last up to 12 weeks)

Comprehensive program including individually prescribed and monitored exercise, and individual and group educational sessions aimed at reducing risk factors and secondary events.

Phase III of Cardiac Rehabiliation

may last 6 months or more

patients no longer receive continuous telemetry monitoring during exercise and are more independent.