Transcript Board_Review_Cards

Cardiology II
Pa. A.C.E.P. Written Board Exam
Review Course
Cardiology II
Topics to be Covered
ƒ Chest Pain
–DDx
–Principles of Management
ƒ Myocardial ischemia & infarction
–Dx
–Rx
ƒ Heart failure
* Basically covering pages 187 to 194 and
325 to 357 in Tintinalli (edition # 4)
General Approach to the
Patient with Chest Pain
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Assume all have emergent condition
Ensure rapid evaluation by doctor
H & P should be done in < 10 minutes
Priorities to determine :
–Is life-threatening etiology present ?
–Is the pain potentially from cardiac ischemia ?
ƒ Also should examine neck, back, abdomen, &
peripheral pulses (at a minimum)
Pathophysiology of Chest Pain
ƒ Two main categories :
–Somatic
ƒ From chest wall
–Visceral
ƒ Less precisely located
ƒ Myocardial ischemia pain
–Can be transmitted by sympathetic or visceral
fibers
–May be indistinguishable from other thoracic
sources
Classification of Etiology of Chest
Pain
ƒ Classed by anatomic site
–Cardiac
–Vascular
–Pulmonary
–Musculoskeletal
–GI
–Misc.
Classification by DDx Severity
ƒ Emergent
–Acute MI, unstable angina, aortic dissection, pulm.
embolus, esophageal rupture, pneumothorax,
pericarditis
ƒ Urgent
–Valve problems, esophageal spasm, esophagitis,
referred pain from abdomen ,pneumonia, pleuritis
ƒ "Benign"
–chest wall pain, costochondritis, Tietze's syndrome,
hyperventilation, slipping rib syndrome, fibrositis,
thoracic spine disease, thoracic shingles
Coronary Ischemic Syndromes
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CAD causes half of deaths in middle age adults
1.7 million admissions per year
rate of confirmed MI is 28 to 50 %
rate of inappropriately discharged MI's is 4 %
Missed MI has 26 % mortality
Admitted MI has 12 % mortality
Missed MI is highest dollar award in EM
malpractice
Risk Factors for CAD
ƒ Male or post-menopausal female
ƒ Hypertension
ƒ Cigarette smoking
ƒ Hypercholesterolemia
ƒ Diabetes
ƒ Sedentary lifestyle
ƒ Obesity
ƒ Positive family history
ƒ Cocaine use
Typical Historical Features for
Myocardial Ischemic Pain
ƒ Retrosternal or epigastric pain
–Squeezing, crushing, or pressure sensation
ƒ May hold clenched fist to sternum
ƒ Pain may radiate to left shoulder, mandible,
arm, or hand
ƒ May have dyspnea, diaphoresis, nausea,
weakness, dizziness
ƒ May be worsened or provoked by exertion
or relieved by rest
Important Principles to Remember
About Cardiac Ischemic Pain
ƒ Pain character is NOT reliable discriminator
–22 % with sharp chest pain have ischemia
ƒ 25 % of MI's are "silent"
ƒ Elderly with MI may have only one of :
–syncope
–weakness
–nausea
–dyspnea
ƒ History is more important than ancillary studies
Considerations About Physical
Exam for Patients with MI
ƒ Normal P.E. does not exclude myocardial
ischemia
ƒ Physical findings rarely contribute to Dx
of MI
ƒ Chest wall tenderness present in 15 % of
MI's
ƒ Altered heart rate or BP does not assist in
Dx
Use of Electrocardiography for
Chest Pain
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Can screen atypical presentations
Can evaluate non-ischemic causes
Stratifies risk of adverse outcome
Tells if thrombolysis indicated
Is diagnostic of MI in only 25 to 50 %
of confirmed MI's
ƒ 13 % of MI's may have fully normal
EKG
Risk Stratification by EKG
ƒ EKG findings indicating need for
admission to I.C.U. :
–Elevated ST segments
–New inverted T waves
–LVH
–LBBB
–Paced rhythm
Serum Markers for Dx of Acute MI
ƒ Most accepted & accurate Dx technique
ƒ Normal serum levels of any marker DO
NOT exclude ischemia as etiology
ƒ If serum marker is positive, then MI can be
"ruled in"
ƒ If serum marker is negative, then MI
CANNOT be "ruled out"
ƒ Choices for early serum markers :
–Myoglobin, CK, CK-MB, Troponin T or I, Myosin Light
Chains
Serum Myoglobin as MI Marker
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Elevated in one hour
Positive in 100 % by 3 hours
Peaks at 4 to 12 hours
Also elevated in :
–Skeletal muscle injury
–Heavy alcohol use
–Renal failure
–Shock
Use of CK MB Isozyme for Dx
of Acute MI
ƒ Specific for acute MI
ƒ Positive in 90 % at 3 hours
ƒ Earlier detection by increase in MB-2 to MB-1
ratio
ƒ Remember CK MB & other cardiac markers do
not identify patients with unstable angina who
need to be admitted
ƒ Current useful panel :
–Myoglobin, Mass CK, & Troponin T
Echocardiography for Dx of Acute
MI
ƒ Useful for patients with :
–Non-diagnostic EKG changes
–LBBB
–Paced rhythm
–Suspicion for pericardial effusion
ƒ Can document extent of ischemia &
amount of myocardium at risk
ƒ Must be done during episode of pain
to be diagnostic
Chest X-ray to Assist in Dx of
Acute MI
ƒ Should be done for all patients with
suspected ischemia
ƒ Allows rapid rule-out of :
–Pneumonia
–Pneumothorax
–Aortic dissection
–Concurrent CHF
ƒ Is usually normal with acute MI
Provocative Tests for
Myocardial Ischemia
ƒ Exercise EKG positive in 50 to 80 % with
symptomatic CAD
ƒ Exercise thallium has higher sensitivity
ƒ IV dipyridamole or dobutamine thallium can
eval patients unable to do exercise test
ƒ Low risk pts with normal EKG & stress test
can be D/C'ed
ƒ Pts with neg enzymes need stress test prior
to D/C to R/O unstable angina
Features of Typical Angina
ƒ Pain lasts 5 to 15 minutes
ƒ Precipitated by physical or emotional
exertion
ƒ Relieved by rest or sublingual TNG in < 3
min
ƒ Retrosternal in 90%
ƒ May have "angina equivalents"
Features of Variant (Prinzmetal's)
Angina
ƒ Occurs at rest
ƒ May be from tobacco or cocaine
ƒ Defined by elevated ST segment during
attack
ƒ Thought to be due to coronary spasm
ƒ Usually releived with TNG
ƒ Can cause MI
ƒ Rx with Beta blockers may result in
unopposed alpha vasoconstriction
Defining Features of Unstable
Angina
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New or recent onset
Increased frequency
More severe intensity
Provoked by less exertion
Less responsive to TNG
Occurs at rest
Features of Aortic Dissection
as a Cause for Chest Pain
ƒ Mostly in hypertensive males age 50 to 80
ƒ Predispositions:
–Marfan's, Coarctation, bicuspid aortic valve, AS
ƒ Classed by Debakey (Types I-III) or Stanford
(Types A,B)
ƒ Can occlude carotids, limb vessels, spinal
or coronary arteries, or cause aortic
regurgitation or hemopericardium
Chest X-ray Findings Indicating
Possible Aortic Dissection
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Wide mediastinum (> 8 cm on AP film)
Blurring of aortic knob
Left pleural cap
Left pleural effusion
Clouding of aortopulmonary window
Deviation of trachea to right
Deviation of NG tube to right
Depression of left mainstem bronchus
Separation of Ca plaque from aortic edge > 6 mm
Normal chest X-ray in 10 %
Dx and Rx for Aortic
Dissection
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TEE proably best
CT & angio have false negatives
Trans-thoracic echo insensitive
If proximal should get stat
cardiothoracic surgery consult
ƒ If distal usually treated medically
(antihypertensive meds)
Usual Sx of Pericarditis
ƒ Acute onset pain, then steady &
severe
ƒ May radiate to back, neck, or jaw
ƒ May be relieved by sitting up & leaning
forward
ƒ May be pleuritic or worse with chest
motion
ƒ May have pericardial friction rub
Usual EKG Findings Sequence
with Acute Pericarditis
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1. PR segment depression
2. Diffuse (all leads) ST segment elevation
3. T wave inversion
4. Resolution of ST and T changes
Other Cardiac Conditions to Consider
that May Cause Chest Pain
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IHSS
AS
MVP
MS (mitral stenosis)
–Features:
ƒ diastolic murmur
ƒ LAE on CXR
ƒ Broad biphasic P wave in V1
ƒ Echo is diagnostic
Risk Factors for Pulmonary
Embolism
ƒ General
–Age, obesity, pregnancy, immobilization, surgery
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Trauma
Medical illness
Vasculitis
Acquired hematologic disorders
Inherited disorders of coagulation or
fibrinolysis
ƒ Drugs or medications
The 3 Features of Virchow's Triad
(predispositions to venous thrombosis)
ƒ Venous stasis
ƒ Vessel wall inflammation or damage
ƒ Hypercoagulability
Sx and Signs of Pulmonary
Embolus
ƒ Classically chest pain, dyspnea, tachypnea,
tachycardia, hypoxemia
ƒ CXR may show Hampton's hump, Westermark's
sign, infiltrate, or pleural effusion
ƒ EKG may show S1, Q3, T3 (only in 6 %), right heart
strain or RAD, sinus tach, NSSTT changes
ƒ Hypoxemia in 75% but normal ABG does not
exclude Dx
ƒ Pulm. angio is "gold standard" for Dx
V/Q Scan Interpretation
Conclusions from PIOPED Trial
ƒ Normal scan effectively excludes the Dx of PE
ƒ Low or intermediate prob. scan requires
further Dx testing
ƒ High prob. scan in patient with high clinical
suspicion should receive anticoagulation Rx,
& further Dx testing not needed
ƒ Alternative Dx scheme is to use results of leg
venous Doppler to R/O DVT
Myocardial Ischemia and Infarction
Epidemiology
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700,000 deaths per yr. in U.S.
50 % of deaths are prehospital
1,300,000 nonfatal MI's per yr.
Most common cause is
atherosclerosis of epicardial coronary
arteries (CAD)
7 Major "Classic" Risk Factors for
CAD
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Age
Male
Family history of CAD
Cigarette smoking
HBP
Hypercholesterolemia
Diabetes mellitus
Myocardial Ischemia
Etiology
ƒ Results from imbalance of myocardial
O2 supply & demand
–Decreased myocardial O2 supply
–Decreased coronary perfusion
ƒ Affected by BP, HR, Anemia, Preload,
Afterload, Contractility
Two Changes in Myocardial
Cells Produced by Ischemia
ƒ Electrical activity
–Potential difference between normal &
ischemic cells results in arrhythmias
ƒ Contraction
–Loss of diastolic relaxation
–Hypo- or a-kinesis
–Decreased ejection fraction
Unstable Angina Pathogenesis
ƒ Starts with disruption of atheromatous
plaque by fissuring
ƒ Results in :
–Platelet aggregation
–Thrombus formation
–Fibrin accumulation
–Hemorrhage into plaque
Beneficial Effects of Nitrates
in Rx for Angina
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Increased venous capacitance
Reduced ventricular volume
Better subendocardial perfusion
Coronary artery dilation
Improved collateral flow
Afterload reduction
Remember tolerance may develop,
so nitrate free interval each day is
useful
Use of Beta Blockers & Calcium
Channel Blockers for Angina
ƒ B1 selective agents and those with ISA have no
major differences in effectiveness
ƒ Beta blockers relatively contraindicated for :
–Asthma, COPD, CHF, AV block, Prinzmetal
ƒ Ca channel blockers effective for stable &
variant angina
ƒ However NOT effective in reducing infarct risk,
size, or mortality for unstable angina or
evolving MI
General Sequence of Rx for
Unstable Angina
Oxygen
Aspirin
TNG
Heparin
Esmolol
Diltiazem
Acute Myocardial Infarction
Pathogenesis
ƒ Coronary plaque fissuring &
hemorrhage
ƒ Platelet aggregation & thrombosis at
site of narrowing
ƒ Coronary artery spasm
ƒ Coronary artery embolism
The "Four D's" Time Intervals
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Goal is to minimize each time interval
Door to Data (EKG)
Data to Decision to treat
Decision to Drug (thrombolytic)
administration
Non Q-Wave Versus Q-Wave
Infarction
ƒ Q-Wave = transmural infarct
–Tend to be larger
–Usually have ST segment elevation
ƒ Non Q-Wave = nontransmural or
subendocardial
–More likely to have recurrent infarct or
subsequent angina
–Usualy have ST segment depression
ƒ Both may have T wave inversions
EKG Localization of Infarcted
Area
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Inferior : II, III, F
Anteroseptal : V1, V2, V3
Lateral : I, L, V4, V5, V6
Anterolateral : V1 to V6
Right ventricular : V4R to V6R
Posterior : tall R and ST depression in V1,
V2
Serum Markers for Diagnosis of
Acute MI
Marker
Earliest Rise
(hours)
Peak
(hours)
Normalize
(day)
Myoglobin
1 to 2
4 to 6
First
CK-MB
3 to 4
12 to 24
Second
Troponin
3 to 6
12 to 24
Seventh
Radionuclide Scans for Dx of
Acute MI
ƒ Generally sensitive but nonspecific
ƒ Technetium pyrophosphate
–Infarct shows as hot spot
–Positive in 10 hours
–85 % sensitive for Q-Wave infarct
–50 % sensitivity for non Q-Wave infarct
ƒ Thallium sestamibi
–Infarct shows as cold spot
–Less sensitive for small or non Q-Wave infarcts
Complications of Acute MI :
Dysrhythmias
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Site of infarct does not influence dysrhythmia incidence
Sinus tach : should treat underlying cause
Sinus brady : treat only for hypotension or escape PVC's
PAC's : usually do not need Rx
PSVT : treat with vagal maneuvers, adenosine, or cardioversion
Atrial fib : Rx for rate control
Atrial flutter : Rx with cardioversion
Junctional tach : Rx usually not needed
PVC's : Rx usually not needed
AIVR : Rx usually not needed
V fib or V tach : should always Rx
Conduction disturbances (blocks)
Indications for Pacemaker
(Transvenous) for Acute MI
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Hemodynamically unstable bradyarrythmias
Second degree AV block (Mobitz type II)
Third degree (complete) AV block
New RBBB & LAFB
New RBBB & LPFB
New LBBB & first degree AV block
Alternating BBB
Asystole (no escape rhythm)
Atrial or ventricular overdrive for incessant atrial
flutter or Torsade
ƒ Controversial for new LBBB or RBBB
Killip-Kimball Clinical
Classification of LV Pump Failure
Class
Clinical
Features
Incidence
(%)
Mortality
(%)
I
No CHF
30
II
Mild CHF
40
15 to 20
III
Frank Pulm.
Edema
10
40
IV
Cardiogenic
Shock
20
80+
5
Forrester-Diamond-Swan
Classification of LV Failure
Class
Cardiac
Index
PAWP
(mm Hg)
Mortality
(%)
I
>2L/min/m2
< 18
3
II
>2L/min/m2
> 18
9
III
<2L/min/m2
< 18
23
IV
<2L/min/m2
> 18
51
Rx for Pulmonary Vascular
Congestion with MI
ƒ Vasodilators
–Most rapid effect on PAWP
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Morphine
Diuretics
Inotropes
IABP (consider if inotropes > 3 hrs.)
Surgery
–Consider if "mechanical" complication or
inotropes needed > 24 hrs.
"Mechanical" Complications
of Acute MI
ƒ Cardiac (LV wall) rupture
–Mortality 95 %
ƒ VSD
–Sudden onset pulm. edema & new harsh systolic
murmur
ƒ Papillary muscle dysfunction / rupture
–May show new murmur &/or pulm. edema
ƒ Rx by hemodynamic support (? IABP) &
consult surgery
Other Complications of Acute MI
ƒ Thromboembolism
–Prevent with routine SQ heparin 5000 units q day
ƒ Mural thrombosis
–More common with anterior MI's
–Rx with full heparinization
ƒ Pericarditis
–Rx with NSAID's ; Rarely need steroids for Dressler's
ƒ RV infarction
–Present with hypotension, JVD, & clear lungs
–Sensitive to nitrates & diuretics
General Management
Considerations for Acute MI
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O2 / IV / Monitor
Correct serum potassium & magnesium as needed
Pain relief with IV MS or nitrates
Nitrates
Aspirin
Heparin (5000 u bid for most pts. vs. full for thrombolysis)
Magnesium IV (debatable)
Beta blockers
Thrombolytics
Admit
–To ICU if ongoing pain, EKG changes, arrhythmias,
hemodynamic instability
Contraindications to Use of
Beta Blockers for Acute MI
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Heart rate < 60 bpm
Systolic BP < 100 mm Hg
Moderate to severe LV dysfunction
Peripheral hypoperfusion
Second Degree AV block
Severe COPD / asthma
General Aspects of Thrombolytic
Therapy for Acute MI
ƒ Reduces early mortality by 1/3 to 1/2 (from 15
% to 5 %)
ƒ Greater mortality reduction with earlier use
ƒ Improves LV function
ƒ All current agents activate plasminogen to
plasmin which then dissolves fibrin
ƒ General failure rate is 20 % & reocclusion rate
is 15 %
ƒ Bleeding complication rates similar between
different current agents
Features of Streptokinase (SK)
ƒ Cost : $ 300
ƒ Half life 23 minutes
ƒ Antigenic : made from beta-hemolytic
strep cultures
ƒ Allergic reactions in 5.7%
ƒ Dose : 1.5 million units IV over 1 hour
ƒ GUSTO trial showed overall mortality
7 % compared to 6 % for tPA
Features of APSAC
(anistreplase)
ƒ Cost : $ 1675
ƒ Half life 90 minutes
ƒ Antigenic (same complications as for
SK)
ƒ Dose : 30 units IV over 2 to 5 minutes
(one-time)
ƒ Should not co-administer heparin
Features of Tissue Plasminogen
Activator (tPA or alteplase)
ƒ Cost : $ 2200
ƒ Half life 5 minutes
ƒ Non-antigenic (made from vascular
endothelial cells via recombinant DNA)
ƒ Dosing :
–"Front-loaded" : 100 mg over 90 min.
–"Traditional" : 100 mg over 3 hours
ƒ Requires concurrent heparin to prevent
early reocclusion
Situations Where tPA is Probably
Thrombolytic of Choice
ƒ Allergy to SK or APSAC
ƒ Prior use of SK or APSAC within 6
months
ƒ Strep infection within 12 months
ƒ Hemodynamic instability
ƒ Anterior or lateral MI's if < 75 years
age
ƒ Presenting < 4 hours from Sx onset
Standard Eligibility Criteria for
Thrombolytic Therapy
ƒ Sx consistent with acute MI & < 12 hrs duration
ƒ EKG criteria (one of these 3) :
–> 1 mm ST elevation in 2 contiguous limb leads
–> 2 mm ST elevation in 2 contiguous precordial leads
–New LBBB
ƒ No contraindications
ƒ Patient not in cardiogenic shock (these pts.
should undergo emergency angiography &
mechanical reperfusion if available)
Absolute Contraindications for
Thrombolysis for Acute MI
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Active internal bleeding
Altered level of consciousness
CVA in past 6 mo. or any hemorrhagic CVA ever
Intracranial or intraspinal surgery in past 2 months
Intracranial or intraspinal neoplasm, aneurism, AV malformation
Known bleeding disorder
Persistent severe hypertension (200/120)
Pregnancy
Head trauma within one month
Possible aortic dissection or pericarditis
Trauma or surgery within 2 months that could result in bleeding in
a closed space
Relative Contraindications to
Thrombolysis for Acute MI
ƒ Active peptic ulcer disease
ƒ CPR for > 10 minutes
ƒ Current use of oral anticoagulants
ƒ Hemorrhagic ophthalmic conditions
ƒ Chronic uncontrolled HBP (diastolic > 100)
ƒ Ischemic or embolic CVA > 6 months ago
ƒ Trauma or surgery > 2 weeks but < 2 months
ago
ƒ Subclavian or IJ vein cannulation
Complications of Thrombolytic Rx
ƒ Allergic reactions (SK & APSAC)
ƒ Hypotension (10 to 13 %)
ƒ Hemorrhagic
–Overall rate is 5 to 6 % with each agent
–Hemorrhagic stroke rate about 0.5 % for
SK & APSAC and about 0.7 % for tPA
ƒ Reperfusion arrhythmias
–Most do not require Rx
Rx Sequence if Major Bleed
from Thrombolytic Occurs
ƒ D/C thrombolytic
ƒ Protamine (1 mg per 100 units heparin) IV
ƒ Consider :
–Crystalloid infusion
–Transfusion with packed cells
–FFP 2 to 6 units
–Cryoprecipitate 10 units
–Platelet packs ( 6 to 12 units)
–Aminocaproic acid
–Tranexamic acid
Indications for Success or
Effectiveness of Thrombolysis
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Relief of pain
Resolution of elevated ST segments
Reperfusion arrhythmias
Attaining hemodynamic stability
Resolution of hypotension
Classification for Angioplasty
(PTCA) for Acute MI
ƒ "Immediate or Adjunctive" = done in
conjunction with or immediately following
thrombolysis
ƒ "Rescue" = done when thrombolysis
unsuccessful
ƒ "Primary or Direct" = use of PTCA
immediately instead of thrombolysis
–Main indications are : cardiogenic shock,
uncertain Dx, or pts. with contraindication to
thrombolysis
Causes of High Output CHF
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Anemia
Thyrotoxicosis
Large AV shunts
Beriberi
Paget's Disease
Sympathomimetic overdose
Sx and Signs in Heart Failure
ƒ Sx :
Left Sided
Right Sided
–Dyspnea
–Orthopnea
–PND
–Fatigue
–Nocturia
–Peripheral edema
–RUQ abd. pain
–Anorexia
–Nausea
ƒ Signs :
–Diaphoresis
–Tachycardia
–Tachypnea
–Rales, wheezes
–S3 gallop
–JVD
–Peripheral edema
–Hepatomegaly
–HJR
CXR and EKG Findings in CHF
ƒ CXR :
–PVR
–Kerley B lines
–Alveolar pulm.
edema
–Cardiomegaly
–Pleural effusions
–Hepatomegaly
ƒ EKG :
–LVH
–RVH
–LAE
–RAE
–Conduction
abnormalities
–Reduced voltage
–+/- ischemia
Rx of Chronic CHF
ƒ Correct underlying cause if possible
ƒ Restrict physical activity
ƒ Vasodilators
–ACE inhibitors shown to prolong
survival
ƒ Dietary restriction of sodium intake
ƒ Diuretics
ƒ Inotropes
Rx for Acute Pulmonary
Edema (Acute CHF)
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High flow O2 / IV / monitor
Sit pt. upright
TNG : spray or SL, then IV
Diuretics
Inotropes (dobutamine or dopamine)
Morphine
Consider PEEP (may reduce preload but may also
reduce cardiac output)
ƒ Consider aminophylline
ƒ Consider phlebotomy
ƒ Evaluate for correctable cause