A tale of 3 patients...
A short circuit, a steal and the blues
Rami Khouzam, MD
May 20, 2005
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 < 1.5 NG/ml).
– Cardiac catheterization: Lt Cx bifurcation lesion
at the level of OM2, and multiple RCA lesions not
amenable to intervention.
EKG 1
EKG 2
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
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, 2005;38:210-211
Case 2
Where is the Justice?
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, tonguebiting, 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
PE:
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T 98.9o
P 66
R 16
BP 190/64
HEENT: unremarkable.
Neck: supple without JVD or bruits.
Chest: CTAB.
CVS: RR @ ~60, nl S1/S2, no S3, +S4; PMI NDP
II/VI SM @ RUSB -> neck; I/IV DM @ 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
Differential Dx of Unequal Pulses
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Thoracic Outlet Syndrome
Arteritis (Takayasu’s or temporal)
Embolism
Raynaud’s 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
http://www.geocities.com/davidscerri
/unequal_UL_pulses.htm
• 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
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
McIntyre, K., Subclavian Steal
Syndrome, eMedicine, Oct 2003.
• Arch aortogram
• MRA
• 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
McIntyre, K., Subclavian Steal
Syndrome, eMedicine, Oct 2003
• 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
El-Mallakh, R.S., Subclavian Steal
Syndrome, Ferri's Clinical Advisor,
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
McIntyre, K., Subclavian Steal
Syndrome, eMedicine, Oct 2003.
• 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
McIntyre, K., Subclavian Steal
Syndrome, eMedicine, Oct 2003.
In Essence…
• Development of (-) pressure gradient
between vertebrobasilar and vertebralsubclavian artery junctions
• Subsequent retrograde filling of the
subclavian artery via the vertebral artery
causes the subclavian artery to “steal”
blood from the vertebrobasilar system
Chan-Tack, K., Subclavian Steal
Syndrome: A Rare but Important
Clinical: Signs & Symptoms
Muscle cramping
Cerebral ischemia
- Dizziness
- Syncope
- Dysarthria
- Visual loss
- Diplopia
- TIA’s
BP differences
• Proximal subclavian occlusion or stenosis
CANNOT be present in the absence of a
significant difference in BP between patient’s
arms
• Therefore, A SIMPLE PHYSICAL EXAM can
effectively eliminate significant subclavian
arterial lesions without using angiography or
duplex ultrasonography
El-Mallakh, R.S, Subclavian Steal
Syndrome, Ferri's Clinical Advisor:
Case 3
Out 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
• 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
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: P:81, BP:108/54, RR:10
CVS: Single S2, Normal S1,
RR @ 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 > Lt. leg
Current Admission
• In ER: O2 sat. : 65 %
• ABGs: 7.43/ 29/ 41/ 21/ 74%
(post-intubation on 100% O2)
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
EKG
Chest X-ray:
• Heart size normal
• No lung infiltrates or interstitial edema
CT of the head without contrast:
Normal
TTE (+ contrast echo):
Agitated saline from right femoral vein
TTE (+ contrast echo):
Agitated saline from upper extremity vein
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)
CT-angiogram + coronal reformation,
volume rendered color images:
Injection of dye via right femoral vein
MRI/MRA (few days later):
• Hypoplastic vertebro-basilar system
• Area of hypersensitivity in pons 
suggesting infarct
Le Bonheur Hospital:
Surgery
(Atrial septostomy with repair and
transfer of the IVC drainage from left
atrium to right atrium)
Outcome
O2 sat. 95 - 100 % on RA
Stable 10 months after D/C
No effort intolerance, No DOE
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.
• 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
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
• 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
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
• 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
Physical Appearance
• Normal except for:
– Cyanosis
– Clubbing
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
Diagnosis
The Echocardiogram
• 2-D echo + contrast : Gold standard
Foale, R. Eur. Heart J. 1983
Cyanosis
• Bluish discoloration of lips, nail beds,
ears & malar eminences:  reduced Hb
in small blood vessels
• Central cyanosis: SaO2 < 85 %
(Dark-skinned: SaO2 < 75 %)
Both mucous membranes & skin
• Peripheral cyanosis: Spares mucous
membranes
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
•  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
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
• 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
Am J Med Sci 2005;329(3): 1- In press
OUT OF THE BLUES
Out of the Heart’s blues
Out of the baby blues
Out of the Memphis blues
“A Tale of 3 Patients…”
What have we learned?
• Don’t 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