A tale of 3 patients''' A short circuit, a steal and the blues

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A tale of 3 patients...A short circuit, a steal
and the blues

• Rami Khouzam, MD
• May 20, 2005

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Case 1

• A 65 yo AAM with a PMHx. significant for a recent
  NSTEMI, HTN and ESRD, presented with chest
  tightness.
• Troponin I 53 NG/ml (N lt 1.5 NG/ml).
• Cardiac catheterization Lt Cx bifurcation lesion
  at the level of OM2, and multiple RCA lesions not
  amenable to intervention.

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EKG 1
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EKG 2
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What Now?

• A) Take patient again to the cath. lab
• B) Start GIIbIIIa inhibitors
• C) Repeat testing of cardiac enzymes
• D) Continue same management
• E) None of the above

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• Misinterpretation of ECG due to Cable
  Malfunction A Newly Described ECG error.
• Fluid contamination at the trunk cable connector
  ? impedance change on the V leads cable
• ? leading monitor to view V2 through V6 as the
• same point electrically
• ? the cable was subsequently changed

J Electrocardiol, 200538210-211
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Case 2Where is the Justice?
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Case Report

• O.C. is a 70 y.o. woman who presented with
  syncope (several episodes in past)
• Denied CP, palpitations, prodrome, incontinence,
  visual changes, aura, tongue-biting, or
  post-ictal state
• PMH HTN, CVA (6 yrs ago), GERD
• PSH CABG 1996, Hysterectomy
• SH occ TOB
• FH CAD, DM
• Meds Accupril, ASA, Prevacid

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PE

• T 98.9o P 66 R 16 BP 190/64
• HEENT unremarkable.
• Neck supple without JVD or bruits.
• Chest CTAB.
• CVS RR _at_ 60, nl S1/S2, no S3, S4 PMI NDP
• II/VI SM _at_ RUSB -gt neck I/IV DM _at_ 3rd L
  ICS.
• Abdomen and Neurological exams unremarkable.
• Ext No edema.
• Peripheral pulses 2 throughout except R radial
  and brachial pulses
• Orthostats (L arm) supine 210/90, 52 standing
  220/100, 56
• R arm BP 110/80 mmHg

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Differential Dx of Unequal Pulses

• Thoracic Outlet Syndrome
• Arteritis (Takayasus or temporal)
• Embolism
• Raynauds syndrome
• Thoracic Aortic Aneurysm
• Thromboangiitis Obliterans
• Aortic Dissection
• Coarctation of the Aorta
• Syphilitic Aortitis
• Abnormal Vessel Development
• Iatrogenic (e.g., trauma following catheter
  studies)
• Blalock Shunt

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• CMP/CBC/CIEs/EKG/CXR/CT head all WNL
• Echo
• moderate aortic valve disease (AV area 1.35
  cm2, gradient 50 mmHg) AR, AS with intact LV
  function (EF 65)
• Carotid duplex USG
• R subclavian steal and 60 stenosis of R ICA,
  30 stenosis of R ECA
• Arteriogram
• tortuous lesion of the proximal R subclavian
  with an anomalous retroesophageal course
• Axillary-carotid bypass recommended

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Subclavian Steal Syndrome

• SSS is caused by occlusion of the proximal
  subclavian artery with subsequent retrograde
  filling of the subclavian artery via the
  vertebral artery
• Definition of SSS must include 1) neuro symptoms
  due to cerebral ischemia initiated by ipsilateral
  arm exercise, and 2) diminished BP in the
  ipsilateral arm due to stenosis or occlusion of
  the subclavian artery proximal to the vertebral
  artery origin

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• Arch aortogram

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• MRA

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• Atherosclerosis is the most common cause of
  proximal subclavian artery lesions
• Risk factors include age, sex, FH, smoking, DM,
  HTN, HPL, hyperhomocystinemia
• Although retrograde blood flow in the vertebral
  artery is usually noted angiographically with
  proximal ipsilateral subclavian artery occlusion,
  subclavian steal may also occur with
  hemodynamically significant subclavian artery
  stenosis

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• On the right side, only a small distance
  separates the bifurcation on the subclavian
  artery and the origin of the vertebral artery
  hence, the condition occurs less commonly on the
  right

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Pathophysiology

• Symptoms via flow-related phenomena
• Collateral vessels from the subclavian artery
  enlarge when the lesion in the proximal
  subclavian artery progresses
• The upper extremity becomes dependent on
  collateral vessels distal to the obstruction
• Collaterals serve as points of entry for
  retrograde flow to the arm from the head,
  shoulder, and neck

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• When arm is exercised, vessels dilate to enhance
  perfusion to the ischemic muscle and resistance
  is lowered in the outflow vessels
• Blood is siphoned from the head/neck/shoulders
  through collaterals to supply this low-resistance
  vascular bed satisfying increased O2 demand by
  exercising muscles of the arm
• Resistance in the outflow vessels of the arm
  increases when exercise ceases
• Retrograde flow in the vertebral artery reduced

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In Essence

• Development of (-) pressure gradient between
  vertebrobasilar and vertebral-subclavian artery
  junctions
• Subsequent retrograde filling of the subclavian
  artery via the vertebral artery causes the
  subclavian artery to steal blood from the
  vertebrobasilar system

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Clinical Signs Symptoms

• Muscle cramping
• Cerebral ischemia - Dizziness -
  Syncope - Dysarthria
• - Visual loss
• - Diplopia
• - TIAs
• BP differences

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• Proximal subclavian occlusion or stenosis CANNOT
  be present in the absence of a significant
  difference in BP between patients arms
• Therefore, A SIMPLE PHYSICAL EXAM can effectively
  eliminate significant subclavian arterial lesions
  without using angiography or duplex
  ultrasonography

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Case 3Out of the Blues

• 18 yr AA woman brought to ER found comatose at
  home. Slurred speech, MS changes inability to
  move left arm
• 6 wks prior to admission she had delivered a
  healthy 32 week old infant vaginally

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• Delivery complicated by profuse blood loss 2ry.
  to ruptured vaginal condylomas ? ? hematocrit
  from 49 to 32
• Exercise intolerance, severe fatigue, SOB
  improved after a blood transfusion

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Past Medical History

• Prolonged hospitalization at birth for almost one
  year, but no hx of cardiac surgery
• Some developmental delay ? followed by a
  relatively active life No limitation in daily
  activities
• Clubbing of fingernails and occasional cyanosis
  noted by family

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• Pertinent PE
• Vitals P81, BP108/54, RR10
• CVS Single S2, Normal S1,
• RR _at_ 80 ø m, g, r No JVD
• Lungs CTA bilat. ø w, c, r
• Ext clubbing 3rd degree (fingernails
• toenails) /- cyanosis ø edema
• Neuro Lt. flaccid hemiparesis
• Lt. Arm gt Lt. leg

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Current Admission

• In ER O2 sat. 65
• ABGs 7.43/ 29/ 41/ 21/ 74
• (post-intubation on 100 O2)

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Differential Diagnosis

• Right-to-left shunt
• - Anatomic shunts of systemic venous
• blood into the arterial circulation
• - Congenital heart diseases
• - Pulmonary arteriovenous fistula
• - Multiple small intrapulmonary shunts

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EKG
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• Chest X-ray
• Heart size normal
• No lung infiltrates or interstitial edema
• CT of the head without contrast
• Normal

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• TTE ( contrast echo)
• Agitated saline from right femoral vein

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• TTE ( contrast echo)
• Agitated saline from upper extremity vein

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• Cardiac cath. Lab
• PA catheter from right femoral vein
• (to left atrium left ventricle)
• PA catheter from right subclavian vein
• (to right atrium, right ventricle pulmonary
  artery)

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• CT-angiogram coronal reformation, volume
  rendered color images
• Injection of dye via right femoral vein

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• MRI/MRA (few days later)
• Hypoplastic vertebro-basilar system
• Area of hypersensitivity in pons ? suggesting
  infarct

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• Le Bonheur Hospital
• Surgery
• (Atrial septostomy with repair and transfer of
  the IVC drainage from left atrium to right atrium)

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• Outcome
• O2 sat. 95 - 100 on RA
• Stable 10 months after D/C
• No effort intolerance, No DOE

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Anomalous Drainage of IVC to the Left Atrium

• In the embryo, the sinus venosus receives the
  cardinal, umbilical, and vitelline veins.
• It communicates with primitive atrium via an
  orifice that has a right and left valve.
• Normally, the sinus venosus migrates to the
  right, and the left valve disappears.

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• The right valve usually decreases in size,
  becoming the crista terminalis, Eustachian and
  Thebesian valves.
• If the right sinus venosus valve persists and
  fuses with the superior part of the septum
  secundum, the result is
• An Inferior Vena Cava draining into the Left
  Atrium

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Pathophysiology

• If one of the cavae enters the left atrium, the
  right side of the heart is effectively bypassed
  so that the right ventricle output and pulmonary
  blood flow should fall
• Meadows, W.R. Am. J. Cardiol. 1965
• The left ventricular output theoretically remains
  unchanged because the increment in anomalous
  caval flow into the left atrium is matched by a
  reciprocal decrement in pulmonary venous flow
  into the left atrium

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• IVC normally carries about twice the volume of
  blood as the SVC
• Accordingly an anomalously draining IVC delivers
  a much larger proportion of systemic venous
  return to the left atrium than an anomalously
  draining SVC
• Perloff. 1994

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The History

• Cyanosis from birth or infancy
• Survival into adulthood is the rule with recorded
  cases in the 6th, 7th 8th decades
• Absence or paucity of symptoms in patients with
  cyanosis
• Davis, W.H. Br. Heart J. 1959

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• Effort intolerance, dyspnea and light-headedness
• Right-to-left shunt (over many decades)
  paradoxical embolus brain abcess
• Cause of death generally unrelated to the
  congenital malformation
• Tuchman, H. Am.
  J. Med. 1956

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Physical Appearance

• Normal except for
• Cyanosis
• Clubbing

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Auscultation

• S2 single
• ? right ventricular stroke volume and
• ? pulmonary capacitance
• ? early pulmonary valve closure
• ? synchrony or near synchrony with aortic closure
• Meadows, W. R. Circulation 1961

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Diagnosis The Echocardiogram

• 2-D echo contrast Gold standard
• Foale, R. Eur. Heart J. 1983

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Cyanosis

• Bluish discoloration of lips, nail beds, ears
  malar eminences ? reduced Hb in small blood
  vessels
• Central cyanosis SaO2 lt 85
• (Dark-skinned SaO2 lt 75 )
• Both mucous membranes skin
• Peripheral cyanosis Spares mucous membranes

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Clubbing

• In the 5th Century BC,
• Hippocrates observed that in
• empyema the fingernails
• become curved and the fingers
• become warm especially at their tips
• The term Hippocratic fingers used in early
  writings
• Campbell, D. BMJ 1924

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• ? in thickness of the nail bed and soft tissues
  of the volar surface followed by connective
  tissue proliferation, collagen deposition,
  capillary dilatation, infiltration of lymphocytes
  and plasma cells
• Currie, A.E. Chest 1988

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Mechanism of Clubbing

• Right-to-left shunt
• Megakaryocytes (platelet precursors) bypass
  pulmonary circulation ? systemic circulation ?
  lodge in the tips of the digits (prevailing
  pattern of blood flow)

Dickinson, CJ. Eur. J. Clin. Invest. 1993
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• Once impacted in the capillaries of the digits
  and periosteum release
• - VEGF (Vascular Endothelial Growth Factor)
• - Platelet-Derived Growth Factor
• - Hypoxia-inducible factor-1 ?
• - Hypoxia-inducible factor-2 ?

Border, WA. N. Engl. J. Med. 1994
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Am J Med Sci 2005329(3) 1- In press
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A Tale of 3 Patients What have we learned?

• Dont trust Medicine by rumor, always check for
  yourself
• No technology will replace the importance of a
  good physical exam
• You can publish publishable cases
• Learning is an ENDLESS process