Download PATHOPHYSIOLOGY OF CARDIOVASCULAR SYSTEM

PATHOPHYSIOLOGY OF CARDIOVASCULAR SYSTEM
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Please, define the resting cardiac output!
~5 liters/min
Please, define the resting stroke volume!
~70 ml
Please, define the resting heart rate!
~70/min
What factors can influence the stroke volume?
Preload, afterload and myocardial contractility
What is the backward sign of the left ventricular failure?
Pulmonary congestion
What type of heart failure is caused by beri-beri or anemia?
High-output cardiac failure (Hyperdynamic circulatory failure)
Please, characterize the resting cardiac output in anemia?
It is significantly higher than 5 liters/min.
What form of classification is used in heart failure?
NYHA (New York Heart Association)
Please, name two example to peripheral circulatory failure:
Syncope, circulatory shock
How does the heart rate change in heart failure?
Upon physical exercise, it increases rapidly
Please, define preload!
The rate of venous return
Please, define ejection fraction (EF) and its normal value?
It is a ratio of the stroke volume and the end-diastolic volume. Normal range 55-70%
To which phase of the cardiac cycle can we associate an efficient coronary perfusion?
Diastole
What factor determines the afterload?
Total peripheral resistance
What typical pH abnormality develops in a circulatory shock?
Metabolicus acidosis./ Metabolic acidosis
Please, name the two different hemodynamic phases of distributive shock!
Warm and cold shock
What is the meaning of SIRS?
Systemic inflammatory response syndrome
Normal blood pressure:
120/80 mmHg
What are the upper limits of normal blood pressure?
140/90 mmHg
Below what blood pressure values do we diagnose hypotension in adults?
Below 110/70 mmHg
In case of an increased myocardial workload, how can the coronary circulation provide the
necessary oxygen supply?
Via increased myocardial perfusion (since the oxygen extraction /arterio-venous
oxygen difference-∆AVO2/ is already maximal at rest)
22. Which is the earliest cause of death in an acute myocardial infarction ?/Which is the most
rapidly occurring cause of death in an acute myocardial infarction?
Ventricular fibrillation
23. Please, define the typical duration of an angina pectoris episode!
Less than 30 minutes
24. Please, define Ohm’s law regarding the circulatory system!
R = Δp/Q, R- viscosity; Δp- pressure difference; Q- flow rate
25. Please, define the Hagen-Poiseuille equation! On what parameters does the hydraulic
resistance depend?
R=
8xlxη
π x r4
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According to the Hagen-Poiseuille equation the hydraulic resistance (R) increases
when the length of the tube (l) and/or the viscosity of the fluid (η) increases. It
decreases, when the radius of the tube (r) increases.
How can we determine the mean arterial pressure?
We have to integrate the area under the blood pressure curve during the cardiac
cycle.
How can we estimate the mean arterial pressure at normal heart rate?
Pmean = Pdiast + (Ppulse / 3)
What is the pulse pressure?
Psyst - Pdiast
To what parameter is the pulse pressure directly proportional in healthy individuals?
To stroke volume
Please, define the resting cardiac output in the pulmonary circulation!
~5 liters/min
What is normal value of maximal systolic pressure in the left ventricle?
~140 mmHg
What is the normal value of the end-diastolic pressure in the left ventricle?
~8 mmHg
What is normal value of maximal systolic pressure in the right ventricle?
~24 mmHg
What is the normal value of the end-diastolic pressure in the right ventricle?
~4 mmHg
What is the normal value of pulse pressure in the systemic circulation?
~40 mmHg
What is the normal value of the mean arterial pressure in the systemic circulation?
~90 mmHg
What is the normal distribution of blood volume between the systemic and the pulmonary
circulation?
70-30%
What is the normal value of pulmonary vascular resistance as compared with the systemic
total peripheral resistance?
One -fifth to one-eighth (1/5th to 1/8th)
What pathological condition may be found in the background of the increased resting pulse
pressure?
Insufficiency of the aortic valve
Please, outline (draw) the action potential of the working-muscle fibers!
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(show all four phases)
Please, outline (draw) the action potential of the pacemaker cell!
(show the spontaneously depolarization)
How can we calculate the cardiac output?
Heart rate x stroke volume
Within what mean arterial pressure range is the coronary autoregulation capable of
maintaining a stable coronary perfusion?
50-150 (60-160) mmHg
Which 3 hemodynamic factors determine the oxygen consumption of the myocardium?
1. heart rate
2. contractility
3. ventricular wall tension (strain)
To which factors is ventricular wall tension proportional in the heart (LaPlace-law) (3)?
1. directly proportional to the intraventricular pressure (Pi)
2. directly proportional to the internal radius of the left ventricle (Ri)
3. indirectly proportional to the wall thickness (h)
What form of coronary abnormality may be observed in the background of stable (effort)
angina pectoris?
A minimum of 75 % stenosis, due to an atherosclerotic plaque
What form of coronary abnormality may be observed in the background of unstable
angina pectoris?
Thrombus formation due to the rupture of an unstable atherosclerotic plaque, which
process is followed by spontaneous recanalisation
What form of coronary abnormality may be observed in the background of Prinzmetal angina
(angina varians)?
Spasm of one of the (main) coronary branches
What do we call silent ischemia (silent angina)?
Development of ischemic ECG signs, without chest pain
In most cases, what form of coronary abnormality may be observed in the background of
acute myocardial infarction (AMI)?
Thrombus formation due to the rupture of an atherosclerotic plaque which closes the
lumen permanently and which is not followed by spontaneous recanalisation.
Please, list at least 4 from the risk factors of coronary atherosclerosis!
1. High blood pressure
2. Hypercholesterolemia (dyslipidemias / low HDL)
3. Metabolic (x) syndrome (chronic systemic inflammation)
4. Diabetes mellitus
5. Smoking
6. Left ventricular hypertrophy / dilatation
(7. Age)
What is the typical sign of the the hyperacute phase of an acute myocardial infarction?
ST elevations (T-en-Dome) in leads representing the localisation of the myocardial
injury
In which phase of the acute myocardial infarction can we see „T-en dome” without
pathological Q waves?
In the hyperacute phase
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54. Following the onset of the constrictive type the chest pain – if it is not reversible
spontaneously or upon the administration of coronary dilator drugs – after what time interval do
we regard the event (clinically) as an acute myocardial infarction?
30 minutes
55. What does the abbreviation NSTEMI mean?
Acute myocardial infarction without ST elevation „Non-ST-Elevation Myocardial
Infarct”
56. Please, define the pathological Q wave!
A Q wave, the amplitude and duration of which exceed 25% of the following R wave
and 0.04s (1 mm), respectively
57. Following coronary occlusion, after what time may we detect necrosis using
histopathological methods?
Hours (2-4)
58. Following coronary occlusion, which complication may cause sudden cardiac death within
some minutes or even more frequently within the first hours of the AMI?
Ventricular fibrillation
59. After what time interval following coronary occlusion, can laboratory tests indicate
(confirm) the existence/extent of myocardial necrosis?
After 4-6 hours
60. What is the no-reflow phenomenon?
Microcirculation will not restart despite of reperfusion
61. Please, list the ions that enter or leave the ischemic myocardial fibers to an abnormal extent
in chronological order!
Outflow: 1: K+
Influx: 1: Na+
2: Ca2+
2: H+
62. Please, name the group of compounds which plays a central role in reperfusion damage!
Free Radicals, ROS
63. What is the preconditioning?
Repeated, mild ischemic periods improve the tolerance of myocardium against
ischemia
64. At what time of day does acute coronary syndrome occur the most frequently?
In the morning, usually following waking up/getting up
65. What does the Roy-Sherrington principle state?
Cerebral perfusion is adapted to the changing, activation-dependent oxygen demand
of different brain regions via local redistribution of blood flow.
66. What does the Monroe-Kelly principle state?
The volume of any intracranial compartment may only increase at the expense of
the others, otherwise an increased intracranial pressure develops.
67. Please, list the 3 most frequently occurring direct causes of the ischemic stroke!
1. Severe atherosclerotic stenosis/occlusion of some (several) cerebral vessels
2. Thrombus formation in a a. cerebri branch on the basis of atherosclerotic
plaque
3. Embolism
68. Please, define TIA!
Transient ischemic attack: reversible, transient symptoms of an ischemic cerebral
event, lasting for a maximum of 24 hours, that improve spontaneously.
69. What is the duration of hypoxia that the cortex may survive without permanent damage?
4-5 minutes
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What is the role of glutamate during cerebral ischemia? What ion flows are induced by
glutamate?
Excitatory amino acid (neurotransmitter). It decreases the survival of neurons, it has
distant harmful effects. It causes influx of Ca++ and Na+, it induces K+ outflow.
What is the penumbra? What importance may be attributed to it?
A partially injured area around the ischemic, necrotic center. By early intervention, it
may be saved.
What does the cytotoxic cerebral edema mean?
Na and water influx into the intracellular space (inducing swelling of the cells)
What is the Cushing reflex?
Bradycardia and increased blood pressure due to increased intracranial pressure
Which blood vessels are affected typically by parenchymal bleeding of the brain
(hemorrhagic stroke)?
The penetrating thalamic arteries (thalamoperforator arteries)
What is the abnormality in the background of the development of subarachnoideal
bleeding?
Aneurysm
What are the normal blood pressure values in the pulmonary circulation?
25/15 mmHg
Please, define the cardiac output in the pulmonary circulation! How much blood is found
within the pulmonary circulation in comparison with the systemic circulation?
The cardiac output of the pulmonary circulation is the same as that in the systemic
circulation (5 liters/min). The blood content is about 15-30% of that found in the
systemic circulation.
What does the elevation of the pulmonary wedge pressure indicate? Please, define the
normal range!
Pulmonary congestion, danger of a pulmonary edema
5-12 mmHg
What vasomotor response does hypoxia elicit in the pulmonary circulation?
Vasoconstriction
Please, list the 3 main mechanisms that lead to secondary pulmonary hypertension!
Hypoxia (vasoconstriction)
Congestion (veno-occlusive / cardiac)
Decreased capillary diameter (embolism, fibrosis)
What is the cardiac consequence of pulmonary hypertension?
Cor pulmonale, chronic right ventricular failure
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