Transcript Lecture 20 Final Exam Preparation Part 1

Lecture 20
Adult Echocardiography
Final Exam Preparation
Part 1
Harry H. Holdorf PhD, MPA, RDMS, RVT
Action Potential: Myocardial cellular level
• Phase 0
• Phase 1
• Phase 2
• Phase 3
• Phase 4
depolarization, rapid influx of sodium
Brief repolarization , potassium exits cell
Excitation-contraction coupling-influx of calcium
early repolarization- sodium/potassium pump. Sodium and
calcium are pumped out and potassium in.
Resting membrane potential-sodium and calcium remain inside
and potassium ions remain inside
During what phase does contraction occur?
• Phase 2
Cellular influx of which of the following ions
results in contraction?
• calcium
How does the vagus nerve stimulation affect
heart rate?
• Vagus nerve stimulation decreases HR
Normal timing of the aortic and mitral valves
White arrow: Mitral diastolic flow
Black arrow: Aortic Systolic flow
Valve clicks: Isovolumic contraction and relaxation time
Mitral stenosis or Aortic Regurgitation: which
occurs first?
• Aortic regurgitation is first
Mitral Regurgitation or Aortic stenosis: Which
occurs first?
• Mitral regurgitation is first
Any regurgitant lesion is first, as it will include
the isovolumic periods
Normal timing of left sided pressures
• The first heat sound involves?
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Atrioventricular (mitral and tricuspid valves) closing
Heart sounds
• First:
• Second
• Third
• Fourth
closure of mitral and tricuspid valves
Closure of aortic A2 and pulmonic P2 valves
Early diastolic ventricular inflow
Atrial contraction
Which is louder the first or second heart
sound?
• First heart sound (mitral and tricuspid closure)
What caused the third heart sound?
• Rapid, early diastolic flow into a stiff (non-compliant) ventricle
In patients with A-fib, which heart sound would
be missing?
• Fourth (occurs during atrial contraction)
Thrill
• A palpable murmur; one that can be felt.
• Murmurs of grade V or VI have associated thrills.
A pansystolic (holosystolic) apical murmur
which radiates to the axilla is:
• Mitral regurgitation
Phonocardiography
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Murmurs are created by abnormal blood flow
A diamond shaped flow pattern (crescendo-decrescendo) is a flow murmur and is
created by a stenotic valve
Systolic crescendo-decrescendo murmurs arise from stenotic valves that have flow
across them during systole. This means that the murmur is due to aortic stenosis or
pulmonic stenosis.
Aortic stenosis murmurs radiate to the left side of the sternum. Pulmonic stenosis
murmurs radiate to the left side
Diastolic crescendo-decrescendo murmurs arise from stenotic valves that have
flow across them in diastole. This means that the murmur is due to mitral or
tricuspid stenosis
Mitral stenosis murmurs are located at the apex or the left side.
Tricuspid stenosis murmurs are located in the mid-sternum.
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Any term other than crescendo-decrescendo such as pansystolic, holosystolic, or
decrescendo is created by a regurgitant flow.
Remember: crescendo-decrescendo means stenotic.
Systolic murmurs other than crescendo-decrescendo (such as holosystolic
murmurs) arise from regurgitant valves that have flow across them in systole. This
means that the murmur is doe to mitral regurgitation or tricuspid regurgitation.
Mitral regurgitation murmurs are located on the left side. Tricuspid regurgitation
murmurs are located closer to the suprasternal notch.
Diastolic murmurs other than crescendo-decrescendo (such as diastolic
decrescendo murmurs) arise from regurgitant valves that have flow across them in
diastole. This means that the murmur is due to aortic or pulmonic regurgitation.
Aortic regurgitation murmurs are located at the apex. Pulmonic regurgitation
murmurs are located closer at the mid sternum.
RIGHT SIDED MURMURS ARE MORE LIKELY TO BE AFFECTED BY RESPIRATION.
A patient with a systolic ejection murmur and
diminished A2 has?
• Aortic stenosis
Abnormal pressures and volumes
• Congestive heart failure: Pump failure. Fatigue, shortness of breath,
peripheral edema, and abdominal distention
• Hypovolemic shock: Volume loss. Unable to maintain Blood pressure.
• Left to right vs. right to left shunts
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Most cardiac shunts (VSDs & ASDs) shunt left to right due to higher left sided pressure.
Right sided enlargement and increased pressure.
• Eisenmenger’s Syndrome: PHTN from long-standing left to right shunt and
the reversal of the shunt to right to left.
• Cor Pulmonale: Heart disease secondary to disease of the lung. PHTN, RV
hypertrophy, dilatation.
• Tamponade: increased intra-pericardial pressure causes impaired
ventricular filling and decreased cardiac output.
• Constrictive pericarditis: Fibrosis, thickening of the pericardium restricting
diastolic filling.
Doppler
• Maximum flow is then the Doppler beam is parallel to flow.
Pulsed wave vs. Continuous wave
• Pulsed wave
• Continuous wave
Range resolution
Aliasing
No range resolution No aliasing
What is the typical gradient range for aortic
stenosis?
• 3.0 – 5.0 m/sec
Which valve lesion has the highest Doppler
peak?
• Mitral regurgitation
Characteristics of Flow
• Laminar
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Blood cells move in the same direction with similar velocities: bullet shaped. Also called
parabolic
• Turbulent
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Disturbed flow. Blood cells move in different directions with varying velocities creating
vortices
Laminar flow is…
• smooth
In Laminar flow, where is the area of highest
velocity?
• The center
What is smooth flow in the same direction
called?
• Laminar or parabolic
Factors affecting flow
• Pressure gradient: Driving pressure
• Length of blood vessel: Longer the vessel the greater the resistance
• Diameter of blood vessel: smaller the vessel the greater the resistance
• Blood viscosity: Higher hematocrit equals higher resistance (decreased
velocity, and lower hematocrit equals lower resistance (increased velocity)
Factors affecting jet size
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Flow volume
Color Doppler Gain
Frame rate
Size and configuration of orifice
Size and configuration of receiving chamber
Other inflow into the receiving chamber
Pressure drop across the orifice
Which has the most impact on color Doppler
Jet size?
• Gain
Color Flow Doppler
• Separate imaging and color flow processors
• Pulsed Doppler technique
• Multi-gate systems
• Mean velocity estimator
• Angle dependent
In the apical 5 chamber view, what color is
normal left ventricular outflow tract flow?
• blue
What would you do to prevent ghosting?
• Increase wall filter (because the flashes are low velocity
What is ghosting in color Doppler?
• Flashes of color caused by moving anatomic structures other than blood
flow.
Medicines
• Basic Pharmacology
Routes of Drug Administration
• Topical: local effect- applied where action is desired
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Eye drops, ear drops, skin applications for allergy testing…
• Enteral: desired effect is systemic – via digestive tract
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By mouth via tables, capsules, or drops- Gastric feeding tube-rectally
• Parenteral: Systemic-other routes than the digestive tract
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Injection- into vein, artery, muscle, inhalation, subcutaneous
• Antihypertensives: beta blockers
• Anticoagulants: Heparin (promotes the action of antithrombin III, Coumadin
(interferes with the production of vitamin K dependent clotting factors)
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Aspirin
• Calcium channel blockers
• Chronotropic agents: increases the heart rate
• Inotropic agents: increase the stroke volume by increasing cardiac
contraction
• Nitrates: for occasional angian
• Oxygen
• Sedatives – valium, demeral
• Vasopressors: act by causing constriction of blood vessels, thus increasing
blood pressure
• Diuretics: nephron in the kidney
• ACE inhibitors: inhibits angio-tensin converting enzyme which results in
vasodilation
• Contrast agents: Normal saline is often injected via venous access to r/o
atrial shunts, persistent left SVC.
Allergic Reactions
• Anaphylactic Shock
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The severest form of allergy, which is a medical emergency.
• Antihistamines Benadryl- for treatment of allergic reactions to blood or
plasma.
• Epinephrine: plays a central role in the short-term stress reaction “fight-orflight” . It is secreted by the adrenal medulla.
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Adverse reactions to epinephrine
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Palpitations
Tachycardia
Hypertension
Acute pulmonary edema
Antiarrhythmics
• Antiarrhythmics are used to treat heart rhythm disorders.
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Heart palpitations
Irregular heartbeats
Fast heartbeats
Lightheadedness
Fainting
Chest pain
Shortness of breath
• Lidocaine: used to restore a regular heartbeat in patients with arrhythmia.
• Digitalis: used to treat congestive heart failure and heart rhythm problems
(atrial arrhythmias)
• Atropine: used to treat bradycardia, asystole and pulseless electoral activity
in cardiac arrest.
Analgesics
• Analgesics: any of a diverse group of drugs used to relieve pain.
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Aspirin: reduce fever and inflammation as well as pain
Morphine: acts upon receptors in the brain and spinal cord to decrease the feeling of
pain.
Treatment of Angina
• Nitroglycerin: treats angina pectoris (suffocating chest pain). Occurs when
the coronary arteries become constricted and are not able carry sufficient
oxygen to the heart muscle.
• Beta-adrenergic blocking agents
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Reduces the heart rate and strength of cardiac muscle contractions, thus reducing the
heart’s demand for oxygen.
Calcium channel blockers
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Reduces the rate at which calcium ions differs into cardiac muscles. Controls the force of
heart contractions and reduce arrhythmia, tachycardia, and hypertension.
Dilate coronary blood vessels and increase blood flow to cardiac muscle.
Others
• Antihypertensive agents
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Treats hypertension.
Reduce blood pressure and reduce the work required by the heart to reduce blood and
myocardial consumption.
• Anticoagulants
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Prevent clot formation.
Asprin