Cardiac Imaging: Echo

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Cardiac ImagingEcho
Blood moving away From transducer Blue Blood
moving toward Transducer Red / Orange Turbulent
blood flow Green
Echocardiogram uses ultrasound reflection and
absorption to create chamber images and doppler
technology to determine rate and direction of
blood flow
Transducer
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Echocardiogram
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Stress Echocardiogram
End Systolic Resting
End Diastolic Resting
End Diastolic Max Ex
End Systolic Max Ex
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Echocardiogram Apical 4 Chamber view
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Septum
Apex of Heart
Apex of Heart
Papillary Muscle
RV
LV
AV
TV
MV
RA
LA
Tricuspid valve
Aortic valve
Mitral Valve
Right Atrium
Interatrial Septum
Left Atrium
Apical 4 Chamber View
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Transesophageal Echocardiagraphy

• Advantages of TEE
• Lung air does not attenuate the sound beam
• Works better with COPD patients
• May be use during surgery
• Better visualizes
• Mitral valve disease
• Clots or other masses in the heart
• Tears in the aorta
• Prosthetic heart valves

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Nuclear Stress Test Images
Exercise
Normal Test
Rest
Ischemic Areas
Exercise
Abnormal Test
Re-perfused after rest (no permanent damage from
an MI)
Rest
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Cardiac Catheterization (Angiography)

• Invented by the German physician Werner Forssmann
  in 1929
• Passed a catheter into his own right atrium
  through the brachial artery
• Performed under local anesthesia sedation
• Guide wire catheter inserted into femoral or
  brachial artery
• Advanced into the aorta, left ventricle, and
  coronary arteries
• Aortic pressure is recorded
• Contrast medium (dye) is injected into coronary
  arteries
• Real-time moving blood flow images are taken with
  x-ray camera
• Flow through the CAs appears white against
  darker background
• Blockages are seen as a narrowing of the white
  flow
• Contrast medium (dye) is injected into left
  ventricle
• Real-time moving images of LV motion are taken
  with x-ray camera
• Injected dye appears white against a darker
  background
• Pressures in the 4 chambers during systole and
  diastole
• Wall structure and motion
• ESV, EDV, SV, EF
• Heart valve function and pressure gradients
  across valves

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Left Heart Catheterization
Catheter Entering The LV and LAD Artery Via The
Aorta

• Catheter in femoral artery
• Termed left heart catheterization
• Aorta, Aortic pressures
• CA blockages
• Left ventricular function
• LVEDP LVESP
• EF
• ESV
• EDV

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Right Heart Catheterization
Catheter Entering The RA, RV, and Pulmonary
Artery via the SuperiorVena Cava

• Catheter in subclavian or neck vein
• Termed right heart catheterization
• Pulmonary artery pressures
• Pulmonary hypertension
• Right atrial pressure
• Pulmonary capillary wedge pressure
• Same as left atrial pressure
• TC valve assessments
• Pressure gradients, etc.

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Cardiac Catheterization Lab As Viewed Through The
Control Room
Need for emergency CABG during
PTCA 1992 1.5 2000 .014
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LAD Catheterization Video
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Ventriculogram (LV function)
Courtesy J. Wade Womack
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Cath Images
LAD blockage
RCA blockage
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Cath Images
Left Internal Carotid Artery
Blockage
Left External Carotid Artery
Left Common Carotid Artery
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Cardiac Catheterization (Angiography)

• Risks and Possible Complications
• Bleeding around the point of incision
• Abnormal heartbeats (arrhythmias)
• Allergic reaction to the dye
• Infection
• Blood clots (stroke or pulmonary embolism)
• Perforation or other damage to the arteries
• Heart attack
• Stroke
• Air embolism
• Death (Mortality about .08)

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Angioplasty

• PTCA Percutaneous Transluminal Coronary
  Angioplasty
• Currently used as primary intervention for Acute
  Coronary Syndrome (MI)
• Local anesthesia and sedation
• Catheter with balloon placed at the end is
  advanced into blocked artery
• Balloon is inflated, pressing plaque against
  artery walls
• Arterial lumen is increased facilitating better
  blood flow.
• Stent is often placed to act as scaffold to hold
  artery open
• Stents metal mesh sleeves that prop artery
  open
• Stents are sometimes coated with drugs that
  inhibit re-stenosis
• The site of the stent placement may receive a
  dose of radiation
• Called brachytherapy
• Prevents cell overgrowth in area of stent
  placement
• Glycoprotein IIb/IIIa inhibitors may be used to
  prevent clots during placement
• Plavix and aspirin are usually used to help
  prevent clots post-surgery
• Results are usually only temporary 18 - 40
  chance of re-stenosis
• Blockage almost always requires further
  treatment (PTCA or CABG)

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Angioplasty vs. Throbolytic Therapy

• Angioplasty is the most common effective
  treatment for acute MI
• Better results than thrombolytic (fibrinolytic)
  therapy (ThT)
• The use of Streptokinase, TPA, other agents to
  dissolve occlusion
• PTCA may be used in combination with ThT
• Stabilize patient, give ThT, PTCA done 12 to 48
  hr afterwards
• PTCA has d mortality rate, fewer re-infarctions,
  fewer strokes
• ThT should be done lt 12 hours after symptoms
• PTCA should be done lt 2 hours after arrival at
  hospital
• Benefits from both ThT and PTCA decline after
  time windows
• Bottom Linethe earlier the better for both
  interventions
• Use of stents for acute MI angioplasty seems to
  improve outcomes
• Stents associated with a 19 d in re-infarction
  or repeat PTCAs

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Mortality rate for PTCA vs Thrombolytic Therapy
in Acute MI
Mortality
N 395 395 103 1138
3145 20,683 2606
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Outcomes for PTCA with Stent vs. PTCA only
Percent
Mortality
Reocclusion
Emergency CABG
Revascularization of same vessel
Non-fatal MI
Any Event
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Coronary Stents
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Blade Atherectomy
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Rotary Atherectomy
Laser Atherectomy
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Stent Placement
Before Stent Placement
After Stent Placement
Courtesy J. Wade Womack
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Coronary Artery Bypass Graft Surgery (CABG)

• First modern day technique CABG performed in
  1962 by Sabiston
• World most expensive Plumbing Job
• Approximately 45,000 (Sollano 2002)
• General anesthesia, patients chest opened,
  sternum sawed, ribs spread
• Patient is placed on a respirator (ventilation
  machine or ventilator)
• Patients heart is stopped by perfusing the heart
  with potassium
• Person is placed on heart lung apparatus
• Device circulates and oxygenates blood while
  heart is stopped
• Cooling the heart d need for O2
• Blood be cooled while passing through heart-lung
  machine
• Cold saline may be poured over the heart during
  surgery
• Grafts harvested saphenous veins, mammarian
  artery
• Grafts sutured from aorta to CA, bypassing the
  blockage
• Takes 3 6 hours
• After surgery, patient is taken to ICU (CCU)
  where he is weaned off ventilator
• IVs and drainage tubes removed over the next 48
  hours (longer in older people)
• Patients eating on their own after 24 hours and
  rehab is begun within 48 hours
• Patients with no complications go home after
  about 4 days

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Modern Heart Lung Machine
First Heart Lung Machine developed in 1953 and
used in the surgical closure an atrial defect in
an 18 year old girl
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CABG Surgery
Rib Spreader Reveals Heart
Graft be anastamosed (sutured) to CA
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Coronary Artery Bypass Graft Surgery (CABG)

• Risks and Possible Complications
• Risks associated with anesthesia
• respiratory failure
• Bleeding
• Abnormal heartbeats (arrhythmias A-fib /
  A-flutter is common)
• may need pacemaker
• Infection at incision sites
• Blood clots and plaque (stroke or PE, blocking
  of O2 to tissues)
• Memory loss and problems with cognitive function
• Heart attack
• Pneumonia
• Hypotension from being on heart-lung machine r
  Kidney failure
• Heart failure
• Swelling of ankles or feet on the leg where graft
  was removed
• Depression, anxiety and other emotional
  difficulties
• Post Pump Syndrome
• systemic inflamation in lungs r edema, kidneys r
  kidney failure
• Death (Mortality about 1.5..15 for redos)

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Notes on CABG surgery

• CABG is usually not the first consideration for
  treatment
• not done unless the risks of not having the
  procedure are high
• 50 of grafts develop lesions within 10 years
• Rate may be reduced by statin drugs
• 516,000 CABG surgeries done every year
• Routine surgery today
• Very high success rate (97- 99)
• 67 of patients report NO COMPLICATIONS

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Recent Developments In Cardiac Surgery

• Off-Pump Coronary Artery Bypass (OPCAB)
• Same as regular CABG but with no heart lung
  machine
• Drugs such as Adenosine and Esmolol are used to
  slow HR
• Could be performed 30 - 40 of the time when
  CABG surgery is needed
• Minimally Invasive Direct Coronary Artery Bypass
  (MIDCAB)
• Smaller transverse incision
• No sternotomy, done on beating heart (drugs used
  to slow HR)
• Use of radial artery for grafts (grafts last
  longer)
• Gene therapy (inhibits hyperplasia of intimal
  cells)
• Transmyocardial Laser Revascularization (TMLR)
• Lasing holes directly into myocardium to u
  myocardial blood supply
• Based on reptile heart which has no CAs
• Stem cells injected into myocardium of CHF
  patients
• Increase myocardial tissue or form new
  vasculature?
• Stem cells injected into CAs during
  revascularization
• Mixed results some arteries re-stenosed at a
  higher rate