Cardiology II

Pa. A.C.E.P. Written Board Exam

Review Course

Cardiology IITopics 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

ƒ Assume all have emergent conditionƒ Ensure rapid evaluation by doctorƒ H & P should be done in < 10 minutesƒ 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 :–Somaticƒ From chest wall–Visceralƒ 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

ƒ CAD causes half of deaths in middle age adults

ƒ 1.7 million admissions per yearƒ rate of confirmed MI is 28 to 50 %ƒ rate of inappropriately discharged MI's

is 4 %ƒ Missed MI has 26 % mortalityƒ Admitted MI has 12 % mortalityƒ Missed MI is highest dollar award in EM

malpractice

Risk Factors for CADƒ Male or post-menopausal femaleƒ Hypertensionƒ Cigarette smokingƒ Hypercholesterolemiaƒ Diabetesƒ Sedentary lifestyleƒ Obesityƒ Positive family historyƒ 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 sternumƒ Pain may radiate to left shoulder,

mandible, arm, or handƒ May have dyspnea, diaphoresis,

nausea, weakness, dizzinessƒ May be worsened or provoked by

exertion or relieved by rest

Important Principles to Remember About Cardiac Ischemic Painƒ 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

ƒ Can screen atypical presentations

ƒ Can evaluate non-ischemic causes

ƒ Stratifies risk of adverse outcome

ƒ Tells if thrombolysis indicatedƒ Is diagnostic of MI in only 25 to

50 % of confirmed MI'sƒ 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

ƒ Elevated in one hourƒ Positive in 100 % by 3 hoursƒ Peaks at 4 to 12 hoursƒ 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 MIƒ Positive in 90 % at 3 hoursƒ Earlier detection by increase in MB-2 to

MB-1 ratioƒ 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 minutesƒ Precipitated by physical or

emotional exertionƒ Relieved by rest or sublingual TNG

in < 3 minƒ Retrosternal in 90%ƒ May have "angina equivalents"

Features of Variant (Prinzmetal's)Angina

ƒ Occurs at restƒ May be from tobacco or cocaineƒ Defined by elevated ST segment

during attackƒ Thought to be due to coronary

spasmƒ Usually releived with TNGƒ Can cause MIƒ Rx with Beta blockers may result in

unopposed alpha vasoconstriction

Defining Features of Unstable Angina

ƒ New or recent onsetƒ Increased frequencyƒ More severe intensityƒ Provoked by less exertionƒ Less responsive to TNGƒ 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 Dissectionƒ Wide mediastinum (> 8 cm on AP film)ƒ Blurring of aortic knobƒ Left pleural capƒ Left pleural effusionƒ Clouding of aortopulmonary windowƒ Deviation of trachea to rightƒ Deviation of NG tube to rightƒ Depression of left mainstem bronchusƒ Separation of Ca plaque from aortic edge > 6 mmƒ Normal chest X-ray in 10 %

Dx and Rx for Aortic Dissection

ƒ TEE proably bestƒ CT & angio have false negativesƒ Trans-thoracic echo insensitiveƒ If proximal should get stat

cardiothoracic surgery consultƒ 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

ƒ 1. PR segment depressionƒ 2. Diffuse (all leads) ST segment

elevationƒ 3. T wave inversionƒ 4. Resolution of ST and T changes

Other Cardiac Conditions to Consider that May Cause Chest Pain

ƒ IHSSƒ ASƒ MVPƒ MS (mitral stenosis)

–Features:ƒ diastolic murmurƒ LAE on CXRƒ Broad biphasic P wave in V1ƒ Echo is diagnostic

Risk Factors for Pulmonary Embolism

ƒ General–Age, obesity, pregnancy, immobilization, surgery

ƒ Traumaƒ Medical illnessƒ Vasculitisƒ Acquired hematologic disordersƒ Inherited disorders of coagulation or

fibrinolysisƒ Drugs or medications

The 3 Features of Virchow's Triad(predispositions to venous thrombosis)

ƒ Venous stasisƒ Vessel wall inflammation or

damageƒ 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 InfarctionEpidemiology

ƒ 700,000 deaths per yr. in U.S.ƒ 50 % of deaths are prehospitalƒ 1,300,000 nonfatal MI's per yr.ƒ Most common cause is

atherosclerosis of epicardial coronary arteries (CAD)

7 Major "Classic" Risk Factors for CAD

ƒ Ageƒ Maleƒ Family history of CADƒ Cigarette smokingƒ HBPƒ Hypercholesterolemiaƒ 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

ƒ Increased venous capacitanceƒ Reduced ventricular volumeƒ Better subendocardial perfusionƒ Coronary artery dilationƒ Improved collateral flowƒ 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 spasmƒ Coronary artery embolism

The "Four D's" Time Intervals

ƒ Goal is to minimize each time interval

ƒ Door to Data (EKG)ƒ Data to Decision to treatƒ 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

ƒ Inferior : II, III, Fƒ Anteroseptal : V1, V2, V3ƒ Lateral : I, L, V4, V5, V6ƒ Anterolateral : V1 to V6ƒ Right ventricular : V4R to V6Rƒ 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 nonspecificƒ 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

ƒ Site of infarct does not influence dysrhythmia incidence

ƒ Sinus tach : should treat underlying causeƒ Sinus brady : treat only for hypotension or escape

PVC'sƒ PAC's : usually do not need Rxƒ PSVT : treat with vagal maneuvers, adenosine, or

cardioversionƒ Atrial fib : Rx for rate controlƒ Atrial flutter : Rx with cardioversionƒ Junctional tach : Rx usually not neededƒ PVC's : Rx usually not neededƒ AIVR : Rx usually not neededƒ V fib or V tach : should always Rxƒ Conduction disturbances (blocks)

Indications for Pacemaker (Transvenous) for Acute MIƒ Hemodynamically unstable bradyarrythmiasƒ Second degree AV block (Mobitz type II)ƒ Third degree (complete) AV blockƒ New RBBB & LAFBƒ New RBBB & LPFBƒ New LBBB & first degree AV blockƒ Alternating BBBƒ Asystole (no escape rhythm)ƒ Atrial or ventricular overdrive for incessant

atrial flutter or Torsadeƒ Controversial for new LBBB or RBBB

Killip-Kimball Clinical Classification of LV Pump Failure

Class Clinical Features

Incidence (%)

Mortality (%)

I No CHF 30 5

II Mild CHF 40 15 to 20

III Frank Pulm. Edema

10 40

IV Cardiogenic Shock

20 80+

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

ƒ Morphine ƒ Diureticsƒ Inotropesƒ IABP (consider if inotropes > 3

hrs.)ƒ 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

ƒ O2 / IV / Monitorƒ Correct serum potassium & magnesium as neededƒ Pain relief with IV MS or nitratesƒ Nitratesƒ Aspirinƒ Heparin (5000 u bid for most pts. vs. full for

thrombolysis)ƒ Magnesium IV (debatable)ƒ Beta blockersƒ Thrombolyticsƒ Admit–To ICU if ongoing pain, EKG changes, arrhythmias, hemodynamic instability

Contraindications to Use of Beta Blockers for Acute MI

ƒ Heart rate < 60 bpmƒ Systolic BP < 100 mm Hgƒ Moderate to severe LV

dysfunctionƒ Peripheral hypoperfusionƒ Second Degree AV blockƒ 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 functionƒ 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

ƒ Cost : $ 300ƒ Half life 23 minutesƒ Antigenic : made from beta-

hemolytic strep culturesƒ Allergic reactions in 5.7%ƒ Dose : 1.5 million units IV over 1

hourƒ GUSTO trial showed overall

mortality 7 % compared to 6 % for tPA

Features of Streptokinase (SK)

Features of APSAC (anistreplase)

ƒ Cost : $ 1675ƒ Half life 90 minutesƒ 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 : $ 2200ƒ Half life 5 minutesƒ 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 APSACƒ Prior use of SK or APSAC within

6 monthsƒ Strep infection within 12

monthsƒ Hemodynamic instabilityƒ Anterior or lateral MI's if < 75

years ageƒ 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 contraindicationsƒ Patient not in cardiogenic shock (these

pts. should undergo emergency angiography & mechanical reperfusion if available)

Absolute Contraindications for Thrombolysis for Acute MI

ƒ Active internal bleedingƒ Altered level of consciousnessƒ CVA in past 6 mo. or any hemorrhagic CVA everƒ Intracranial or intraspinal surgery in past 2 monthsƒ Intracranial or intraspinal neoplasm, aneurism, AV

malformationƒ Known bleeding disorderƒ Persistent severe hypertension (200/120)ƒ Pregnancyƒ Head trauma within one monthƒ Possible aortic dissection or pericarditisƒ 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 diseaseƒ CPR for > 10 minutesƒ Current use of oral anticoagulantsƒ Hemorrhagic ophthalmic conditionsƒ Chronic uncontrolled HBP (diastolic >

100)ƒ Ischemic or embolic CVA > 6 months

agoƒ Trauma or surgery > 2 weeks but < 2

months agoƒ 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 Occursƒ D/C thrombolyticƒ Protamine (1 mg per 100 units

heparin) IVƒ 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

ƒ Relief of painƒ Resolution of elevated ST

segmentsƒ Reperfusion arrhythmiasƒ Attaining hemodynamic stabilityƒ 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

ƒ Anemiaƒ Thyrotoxicosisƒ Large AV shuntsƒ Beriberiƒ Paget's Diseaseƒ Sympathomimetic overdose

Sx and Signs in Heart Failure

ƒ Sx :–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

Left - Sided

Right - Sided

CXR and EKG Findings in CHFƒ 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

possibleƒ Restrict physical activityƒ Vasodilators–ACE inhibitors shown to prolong survival

ƒ Dietary restriction of sodium intake

ƒ Diureticsƒ Inotropes

Rx for Acute Pulmonary Edema (Acute CHF)ƒ High flow O2 / IV / monitorƒ Sit pt. uprightƒ TNG : spray or SL, then IVƒ Diureticsƒ Inotropes (dobutamine or dopamine)ƒ Morphineƒ Consider PEEP (may reduce preload but

may also reduce cardiac output)ƒ Consider aminophyllineƒ Consider phlebotomyƒ Evaluate for correctable cause