Flashcards in Cardio phys Deck (55)
Blood enters the fetus through...
enters the IVC via the ductus venosus bypassing hepatic flow.
How is most of the fetal blood delivered to the heart?
Foramen ovale via the IVC/ductus venosus.
How does the ductus arteriosis work?
Sends deoxygenated blood from the right atrium/pulmonary artery into the aorta where it is delivered via the descending aorta/umbilical arteries to the mother.
What closes the ductus arteriosis in a newborn?
Following increased O2 from respiration and a DECREASE IN PROSTAGLANDINS.
How can indomethacin be used in infants?
Helps to close the ductus arteriosis by decreasing prostaglandins.
Results in ligamentum arteriosum.
What does the urachus/Allantois become in the adult?
Median umbilical ligament.
What does the ductus arteriosis become in the adult?
What does the ductus venosus become in the adult?
What do the umbilical arteries become in the adult?
These become the medial umbilical ligament.
Dont confuse this with the urachus that becomes the median umbilical ligament.
What does the umbiical vein become in the adult?
Ligamentum Teres hepatic.
This is contained IN THE FALCIFORM LIGAMENT!!!
Which coronary artery supply the SA and AV nodes?
The right coronary artery.
Note that an infarct would cause nodal dysfunction!!!
A right dominant heart would denote....
That the posterior descending coronary artery comes from the right coronary.
Where is a coronary artery occlusion most commonly found?
Most commonly found in the left anterior descending artery that upplies the anterior 2/3 of interventricular septum.
When does coronary blood flow peak?
What makes up the most posterior side of the heart and what problems can occur if it becomes enlarged?
The left atrium is the most posterior, enlargement can cause dysphagia by compressing the esophagus or hoarsness due to compressing the left recurrent laryngeal nerve (branch of vegas)
How can one calculate the mean arterial pressure?
MAP = Cardiac output x total peripheral resistance.
How is cardiac output maintained early on during exercise?
Mostly through increased HR and stroke volume.
How is cardiac output maintained late into exercise?
It is maintained mostly by HR as Stroke volume tops out.
The heart can only pump out so much at a time and HR comprimises end diastolic volume.
What is pulse pressure?
Systolic Pressure - Diastolic pressure
It is porportional to stroke volume!
What is ejection fraction?
Stroke volume / End diastolic volume.
How can pressure be calculated?
Pressure = Flow x Resistance
What effects resistance most?
The radius of the vessel.
As it increases, resistance is greatly decreased!
How does organ removal effect total peripheral resistance and cardiac output?
Increases total peripheral resistance
Decreases cardiac output.
What is S1 heart sound?
Mitral and tricuspid valves closing. Loudest in the mitral area.
What is S2 heart sound?
S2 correlates to the semilunar (aortic and pulmonic valves) closing. loudest in left upper sternal border.
What is an S3 sound?
In early diastole during rapid ventricular filling phase. Correlates with increased filling pressures (mitral regurg/heart failure) and more commonly in dialated ventricals.
CAN BE NORMAL IN CHILDREN AND PREGNANT WOMEN.
What is the S4 sound?
Late diastole "atrial kick"
high atrial pressure associated with ventricular hypertrophy. Left atrium pushes against a stiff LV wall.
Why would there be wide splitting?
This should make you think of delayed pulmonic closure as seen in pulmonic stenosis or right bundle branch blocks.
When would you see fixed splitting?
Fixed splitting should make you think of there being an atrial septal defect. Regardless of breath, pulmonic valve closure is greatly delayed.
What would cause paradoxical splitting?
Delay in aortic valve closures!
Think aortic stenosis or left bundle branch blocks.
the normal valve order of closure has been reversed!
During breathing the P2 sound is occuring before the A2.
Describe the areas of auscultation.
Aortic (right 2nd intercostal)
Pulmonic (left 2nd intercostal)
Mitral (bottom left)
Crescendo/decrescendo heart sounds
Holosystolic high bitched "Blowing murmur"
Left systolic crescendo with mid diastolic click
Mitral valve prolapse.
Holosystolic harsh sounding murmur
Ventricular septal defect.
What is the J point on an ECG?
The point between the end of the QRS segment and the beginning of the ST segment.
When would one see a U wave in an ecg?
During hypokalemia or bradycardia.
Give the order of the speed of conduction in the heart.
Purkinje > Atria > Ventricles > AV node
What is teh heart conduction pathway?
Why is there a delay between the SA and AV nodes?
To ensure that there is ventricular filling.
Disruptions in this can lead to improper blood flow in the heart.
What predisposes to torsades des pointes?
Long QT interval.
typically due to decreased potassium, magnesium and other abnormalities.
Treatment can be with magnesium sulfate.
Give a breif list of agents that can cause torsades des points
Antiarythmics 1A and III
A delta wave on ECG is very specific for which disorder?
Wolf parkinson White syndome.
A common ventricular pre-excitation syndrome.
May result in a re-entry circuit.
How does atrial natriuretic peptide work?
Relased by ATRIAL CELLS in response to blood volume overload.
Causes vasodilation and decrease in sodium reabsorption in the renal collecting tissue leading to urine loss.
Dilates the afferant arterioles and constrictes the efferent arterioles.
How does B-type natriuretic peptide work? (BNP)
Released from ventricular myocytes in response to increased tension working similarly to ANP but with a longer half life,.'
Used for diagnosing heart failure.
What does the aortic arch transmit vagal messages to?
The solitary nucleus of the medulla. responds to increases and decreases in blood pressure.
How does the carotid sinus communicate with the CNS?
Transmits via the glossopharangeal nerve to the solitary nucleus of the medulla responding to changes in blood pressure.
Pulmonary capillary wedge pressure is related to...
left atrial pressure.
Think about it, its measuring the pressure of the blood coming from the lungs into the left atria.
Normally the pulmonic valves close slightly after the aortic.
This is because as the patient breaths, more blood is brought into the right atrium than the left causing it to close later.
This is due to right ventrical problems
Including pulmonic stenosis
Right bundle branch blocks.
this is an exageration of normal splitting.
This is due to an atrial septal defect in which a left to right shunt is occuring.
Blood is rushing into the right side of the heart faster than the left and thus the pulmonic valve is always closing later than the aortic. Regardless of inspiration.
This is due to aortic valve closure not working properly,.
The aortic valve is closing before the pulmonic during breathing.
Causes might be due to aortic stenosis, and left bundle branch.
what if you heard a continous murmur in the left ingraclavicular region?
Patent ductus arteriosus.
What is the cushing reaction triad?
think of how the baroreceptors will respond to excessive ACTH being produced.