Heart 2 Flashcards
What is the ‘infarction’ phase? When does it occur?
Significant Q wave - much wider than normal
Q may be 1/3 of the height of the QRS
May last for many years after the infarction
Some drugs can cause effects similar to this significant Q
(3rd PHASE)
If someone has an EKG with a ‘Significant Q Wave’ that is much wider than normal. What can be assumed?
That the person has had a previous heart attack in their life.
During a myocardial infarction (heart attack), there are 7 things that may occur. What are they?
- Pain (radiates from neck, jaw, back, shoulder, and left arm)
- Nausea and vomiting
- Catecholamines are released
- Blood sugar usually increases
- Cardiac troponins (I and T found in the blood)
- Enzymes (Creatine kinase / lactic dehydrogenase)
- Troponin/Creatine kinase amounts correlated w/ severity of infarction
What are the two factors that determine the blood flow through a vessel?
Pressure / Resistance
What is the normal pressure of the heart? Where is it usually measured?
- 120/80 mm Hg
2. Arteries
Blood flows from an area of ____ pressure to an area of ____ pressure.
- High
2. Low
The pressure in the right atrium is nearly what?
Zero
Resistance in a blood vessel proportional to two things. What are they?
Length of the blood vessel AND viscosity of the blood
What is laminar flow?
The velocity flow is greater at the center of the vessel than along the outer edges.
There are 2 types of NERVES that affect vascular diameter.
What are they and how do they affect vascular diameter?
Sympathetic:
1. Alpha-adrenergic = (Vasoconstriction)
2. Beta-adrenergic = (Vasodilation) 3. Cholinergic = (Vasodilation)
Parasympathetic nerves = (Vasodilation)
There are 3 HORMONES that affect vascular diameter.
What are they and how do they affect vascular diameter?
- Angiotensin II = (Vasoconstriction)
- ADH (Vasopressin) = (Vasoconstriction)
- Histamine = (Vasodilation)
Circulation is divided into two parts.
- (Not involving lungs)
- (Involving lungs)
What are they?
- Systemic (All parts except lungs)
2. Pulmonary (Lungs)
Systemic circulation is responsible for __% of the blood volume?
79% of the blood volume
Pulmonary circulation is responsible for __% of the blood volume?
12% of the blood volume
What is the average pressure of the ‘capillaries’ when it enters enters and then when it leaves?
30 - 10 mm Hg
What is the average pressure of the ‘arterioles’ when blood enters and when it leaves?
85 - 30 mm Hg
*This is the most important in regulation of blood pressure
What is the most important blood vessel in regulation of blood pressure? (Constricting / Dilating)
Arterioles
What is the function of precapillary sphincters?
Regulate blood flow to capillaries.
Provide intrinsic, loclized regulation of blood flow in capillary beds.
Precapillary sphincters have mechanisms that help regulate blood flow in relation to the local tissues’ need for oxygen.
What is this ability called?
Autoregulation
Water flow across the capillary wall is due to two factors. What are the two factors?
- Capillary Hydrostatic Pressure (CP)
2. Osmotic Force (OF)
The ability for water to diffuse ‘IN’ to the vessel is usually caused by what? This ability is also helped by what protein?
Osmotic Force (OF)
Protein = Albumin
The ability for water to diffuse ‘OUT’ to the vessel is caused by what?
Capillary Hydrostatic Pressure (CP)
True or False:
Osmotic Force (OF) generally changes, but Capillary Pressure (CP) remains the same.
FALSE
Osmotic Force (OF) stays the SAME.
Capillary Pressure (CP) is DIFFERENT.
The ‘constant’ pressure of Osmotic Force (OF) is usually ____ mm Hg. (*In the Left A/V Valve)
23 mm Hg
What is the equation for determining both the ‘Net Filtration Results’ (OUTPUT) and the ‘Net Absorption Results’ (INPUT)?
- Net Filtration Results = Capillary Pressure (-) Osmotic Force
- Net Absorption Results = Osmotic Force (-) Capillary Pressure
What is ‘Edema’?
The presence of excess interstitial fluid in the tissues.
There are 3 main causes of edema. What are they?
- Increased capillary hydrostatic pressure
- Decreased plasma protein (mainly albumin)
- Increased interstitial fluid protein
One of the causes of ‘Edema’ is ‘increased capillary hydrostatic pressure’.
What is this caused by (3 things)?
- Venous Obstruction
- Cardiac Failure
- Retention of body salt and fluid
One of the causes of ‘Edema’ is ‘decreased plasma proteins (mainly albumin)’.
What causes this to occur (3 things)?
- Kidney damage resulting in loss of plasma proteins
- Liver damage - decreased production of plasma proteins
- Malnutrition - not enough protein in the diet
One of the causes of ‘Edema’ is ‘increased interstitial fluid protein’.
What causes this to occur (2 things)?
- Increased capillary permeability - inflammation
2. Decreased lymphatic flow
Increased interstitial fluid proteins in the body can cause what to happen?
Edema
More specifically, ‘Pneumonia’
What are the 3 factors that can change blood pressure (short term)?
- Cardiac Output
- Peripheral Resistance
- Total Blood Volume
Long term regulation of blood pressure is controlled by what?
Hormones
Alcohol acts as a(n) ___________?
Diuretic/Antidiuretic
Diuretic
Alcohol inhibits ADH release
Increases urine production
Increased urine production aids dumping of alcohol from body.
How long does it take the nervous system to regulate blood pressure?
Seconds
What organ(s) monitor blood pressure?
Kidneys
The converting enzyme for Angiotensin is stored in what organ?
Lungs
The Renin-Angiontensin System regulates blood pressure in 3 ways. What are the 3 ways?
- Aldosterone Secretion
- Increase ADH Release
- Vasoconstriction of arterioles
What is Primary Aldosteronism (Conn’s Syndrome)?
Hypersecretion of aldosterone from the adrenal cortex. Leads to:
Hypertension
Increased extracellular fluid volume
Hypernatremia
Potassium Depletion
What is the major etiologic factor in primary aldosteronism (Conn’s Syndrome)? (*Reason why most people have this)
Adrenal adenoma (90% of patients)
What do ACE inhibitors do?
Block the converting enzyme from binding to Angiotensin I so that no Angiotensin II is created.
What are the two major control mechanisms in regulating blood pressure (short term) via the nervous system?
- Baroreceptors
2. Chemoreceptors
In the medulla, there are two centers that help regulate blood pressure (short term) via sympathetic/parasympathetic responses. What are the two centers?
Cardioinhibitory Center (Parasympathetic) B.P. (Decreases) H.R. (Decreases) C.O. (Decreases) Vasodilation (INCREASES)
Vasomotor Center (Sympathetic) B.P. (Increases) H.R. (Increases) C.O. (Increases) Vasoconstriction (Increases)
Baroreceptors are found in 5 locations near the heart. What are the 5 locations?
- Aortic Arch
- Pulmonary Veins
- Right/Left Atria
- Superior/Inferior Vena Cava
- Carotid Sinus
Where are chemoreceptors found (2 locations) and how are they stimulated?
- Aortic Bodies
- Carotid Bodies
Stimulated by DECREASED levels of oxygen and INCREASED levels of CO2 and H+ in blood.
When does circulatory shock occur?
When there is an inadequate bloodflow and/or oxygen delivered to the tissues.
There are 4 types of circulatory shock. What are they?
- Hypovolemic shock
- Anaphylactic shock
- Neurogenic shock
- Cardiogenic shock
What are the characteristics of ‘Hypovolemic shock’?
Reduced blood volume
Caused by hemorrhage/dehydration/ or loss of fluid from burns
Symptoms:
Low B.P. Rapid Pulse Cold Clammy Skin Little Urine Formation Increased Respiration Rate Intense Thirst
What are the characteristics of ‘Anaphylactic shock’?
Rapid drop in B.P.
Result from severe allergic reaction
Histamine causes vasodilation and thus a drop in B.P.
What are the characteristics of ‘Neurogenic shock’?
Spinal cord damage causes decreased sympathetic activity.
What are the characteristics of ‘Cardiogenic shock’?
Inadequate circulation of blood in body tissues due to cardiac failure.
As a result from circulatory shock. The body tries to compensate the ‘LOW BLOOD PRESSURE’ in 10 different ways. What are they?
- Vasoconstriction (Minus vessels of brain/heart)
- Venoconstriction (Extra blood stored in veins)
- Increased Heart Rate
- Increased Respiration
- Increased Thrist
- Secretion of Epi/Norepi
- Secretion of ADH
- Activation of Renin-Angiotensin System
- Contraction of spleen (Extra RBCs stored here)
- Increased Hematopoiesis
When the body compensates for ‘low blood pressure’ after circulatory shock. How long does it usually take for plasma volume to be restored?
Matter of hours
When the body compenstates for ‘low blood pressure’ after circulatory shock. How long does it usually take for ‘plasma proteins’ to be restored? Through what synthesis are they restored?
- Several days
2. Through Hepatic Synthesis
When the body compensates for ‘low blood pressure’ after circulatory shock. How long does it usually take to restore RBCs (Red Blood Cells)?
3-4 Weeks
Hypertension occurs in about __% (1 out of every ___ persons)
- 20%
2. 1 out of every 5 persons
Hypertension causes __% of all deaths.
12%
How does hypertension cause death?
Rupturing vessel in vital organ
Causing Heart/Kidneys to fail
What are the two types of hypertension?
- Primary (Essential)
2. Secondary
What is the most common type of hypertension?
Primary (Essential)
What systolic/diastolic values are considered to be ‘HYPERTENSIVE’?
140/90 mm Hg
What are some of the characteristics/factors of primary (essential) hypertension? There are 10.
- No cause
- 85-90% of all hypertensive patients
- Rare in persons younger than 20
- Occurs 25-50 years of age
- Females more than males
- Hereditary factors involved
- High in blacks than whites
- High salt intake
- Psycho emotional stress
What are some reasons for essential (primary) hypertension?
Increased sensitivity to epi/norepi
Left ventricular hypertrophy causing enlarged heart and oxygen requirement increases. Heart may outgrow its blood supply.
What is the definition of secondary hypertension?
Results from clearly DEFINABLE causes. (Structural/Phsyiological)
What percentage of the high blood pressure population has secondary hypertension?
10-15%
What mechanisms of secondary hypertension are involved in ‘Renal Artery Disease’? What system is involved?
Kidneys
Decreased urine formation
Secretion of vasoactive chemicals
What examples of secondary hypertension are involved with the endocrine system?
- Conn’s Syndrome
2. Adrenal Medulla Tumor
What are the results of having a tumor on the adrenal medulla and blood pressure?
Increased Blood Pressure
Excess Catecholamines created
Increased cardiac output and total peripheral resistance
What are some of the symptoms of essential hypertension? (There are 8 of them)
- Headache (most common)
- Dizziness
- Fatigue
- Blurring of vision
- Polyuria (Increased urine output)
- Polydipsia (Increased fluid intake)
- Muscle Weakness
- Hypokalemia (Low K+ in blood)
What are some dangers of hypertension? (There are 4 of them)
- Future congestive heart failure
- Cerebral blood vessel damage
- Stroke
- Development of atherosclerosis (chronic inflammation of arteries)
There are 6 general treatment methods for hypertension. What are they?
- Regular physical exercise
- Weight loss
- Low refined carbohydrate diet
- Cessation of smoking
- Restriction of salt intake
- Reduce psycho-emotional stress
What causes the first heart sound, “lub”?
The two AV (tricuspid and meitral) valves closing in ventricular systole
What is the diastolic pressure in the pulmonary artery?
10 mm Hg
What is the diastolic pressure in the aorta?
80 mm Hg
After Ventricular Systole, and under normal resting conditions, the pressure reaches ___ mm Hg on the right side and ____ mm Hg on the left side.
- 24 mm Hg
2. 120 mm Hg
How much blood remains in either ventricle at the end of ventricular systole?
50 ml- the end systolic volume
True or false: The valves make the “lub” “dub” heart sounds.
FALSE! The turbulence of the moving blood makes the noise, not the valves.
When does the second heart sound “dub” take place and what makes the noise?
During early diastole, when the semilunar (pulmonary and aortic) valves close.
What is the correct order of cardiac impulse conduction?
SA node, Atrium AV node, bundle of HIS, purkinje fibers, ventricle
What percent of ventricle filling takes place during MID-DIASTOLE?
65-80%
What causes the ‘lub’ heart sound?
Closure of the TWO AV valves
What pressure is reached int he right ventricle under normal conditions?
24 mm Hg
Chronotropic refers to what?
RATE of heart contraction
Cardiac output is measured by what TWO factors?
Stroke Volume x Heart Rate
True or False
A shift of the pacemaker function from the SA node to another part of the heart is called an ‘ECTOPIC’ pacemaker.
TRUE
Ectopic = ABNORMAL
Any pacemaker not started from the SA node is ‘ectopic’
Histamine causes what to occur?
VASODILATION
Precapillary sphincters regulate blood flow in relation to what?
Local tissues need for oxygen
Stimulation of the ‘VASOMOTOR CENTER’ results in what?
DECREASED heart rate