Cardiology Flashcards
ECG
Which leads point in the downward direction?
- aVF (straight down, 90 degrees)
- II (60 degrees)
- III (120 degrees)
Which lead is at 0 degrees?
I
What is a normal range for mean axis of depolarization?
-30 to 110
What is a quick way to know that the axis of depolarization is in the normal range?
“Thumbs up sign”
If pt is positive in lead I and positive in aVF, they are in normal range (0-90)
What part of electrical conduction of the heart does the P wave represent?
Atrial depolarization
What part of electrical conduction of the heart does the QRS complex represent?
Ventricular depolarization
What part of electrical conduction of the heart does the T wave represent?
Ventricular repolarization
If lead I is isoelectric, which lead do you look at to determine direction of the axis of depolarization?
aVF
- If (+), axis is +90
- If (-), axis is -90
If lead II is isoelectric, which lead do you look at to determine direction of the axis of depolarization?
aVL
- If (+), it is -30
- If (-), it is +150
If lead aVF is isoelectric, which lead do you look at to determine direction of the axis of depolarization?
Lead I
- If (+), it is 0
- If (-), it is +180
What does a long QT interval indicate?
Problems with repolarizing the ventricles
How is heart rate calculated?
Find an R wave which peaks on a heavy line – the next heavy black line is 300, followed by 150, 100, 75, 60 and 50
In normal sinus rhythms, the P wave is upright in which leads?
Leads I and II
What does the PR interval indicate?
Time it takes for stimulus to travel from the SA node to the ventricles
What does an inverted T wave represent?
Ischemia
How is the QT interval affected by LV hypertrophy?
Lengthened
How is the QT interval affected by digitalis?
Shortened
How is the QT interval affected by hypokalemia?
Lengthened
How is the QT interval affected by MI?
Lengthened
How is the QT interval affected by Hypercalcemia?
Shortened
How is the QT interval affected by myocarditis?
Lengthened
How is the QT interval affected by thyrocosis?
Shortened
How is the QRS complex affected by AV node escape rhythm?
Narrowed
How is the QRS complex affected by ventricular escape rhythm?
Widened
depolarization wave spreads slowly via abnormal pathway in the ventricular myocardium and not via the His bundle and bundle branches
What is the inherent HR of the following?
- Atria
- AV node
- Ventricles
- Atria: 75/min
- AV node: 60/min
- Ventricles: 30-40/min
What do you look for on an ECG to determine whether the patient has heart block?
Whether every P wave is followed by QRS
Yes => No heart block
What do you look for on an ECG to determine whether the patient has ischemia?
Inverted T wave
Diagnose:
Sinus bradycardia
- Sinus rhythm
- HR = 45
What are the characteristics of 1st degree heart block?
- P is followed by QRS
- PR interval is more than a box away (>250ms)
What are the characteristics of 2nd degree heart block type I?
PR prolongation but just drops a beat out of no where
What are the characteristics of 2nd degree heart block type II?
PR interval is the same before and after the block
(block is below the His-purkinje system)
What are the characteristics of 3rd degree heart block?
- QRS complexes are going at their own rate
- don’t always see a p wave at end b/c it is superimposed on QRS
What are the characteristics of a 2:1 AV block?
Pattern: P, QRS, P, (skip), P, QRS, P, (skip)
What are the characteristics of atrial fibrillation?
- Ventricular rate is irregularly irregular, no discernable P waves
- upper chambers are just quivering
- see slide 88
What are the characteristics of atrial flutter?
- Fast, but it is a circuit in the atrium going about 300 bpm
- See a saw-tooth pattern
Determining L from R bundle branch block
- Bundle branch block
- Widened QRS
- L or R?
- Look at lead V1
- Look at last part of QRS
- If most energy is above the isoelectric line => Right
- If most energy is below the line => Left
- ***Think of a turn signal
- Reference: ekg.academy
What are the characteristics of acute ischemia? How can you tell if it affects the anterior heart or the inferior heart?
- Acute ischemia:
- ST elevation
- Anterior heart
- Leads V2, V3
- Inferior heart
- Leads II, III, aVF
What are the characteristics of an old infarct?
Significant Q wave
- wider than 1 mm or
- length 1/3 QRS amplitude
What are the characteristics of ischemia?
- T wave inversion
- ST interval depression
- See slide 103
What are the characteristics of pericarditis?
- Diffuse ST elevation (everywhere)
- PR depression
- They will have a rub that is worse when they lean forward
Intro to CHF
Decreased perfusion to the kidney activates what system? What is the result?
- Activates Renin - Angiotensin - Aldosterone system
- Result:
- Na and water retention
- Vasoconstriction
What is abnormal about the beta receptors in CHF?
- Downregulate themselves
- not as affected by NE (doesn’t permit vasodilation for example)
What is the effect of the SNS in CHF?
- Increases afterload
- Increases HR
- Impairs contractility
- Increases O2 demand of the heart
- provokes ischemia
- Triggers arrhythmia
- Ca overload and apoptosis
What electrical abnormalities can be present in CHF?
- A-V dysynchrony
- Abnormal impulse propagation in the ventricules
- Atrial or ventricular arrhythmias
What can cause high-output CHF?
- Thyrotoxicosis
- Beri beri
- A-V fistula
What are the physical signs of Right sided CHF?
- JVD
- Tricuspid regurg
- Peripheral edema
- S3 gallop
- Hepatojugular reflex
- pushing on liver makes jugular distention increase
What are the physical signs of Left sided CHF?
- Rales (crackles)
- Mitral regurg
- Pulmonary congestion
- S3 gallop
- early diastolic sound
- Abnormal apical impulse
What are the symptoms of CHF?
- Dyspnea
- Orthopnea
- Parosysmal nocturnal dyspnea
- Cheyne-stokes respiration
- breathing pattern with apnea and hyperventilation
- Nocturia
What is most important for diagnosis of CHF?
Thorough H&P
What are some causes of CHF?
- CAD (Most common)
- Valvular disease
- Congenital disease
- Tachycardia
- Chagas
- Toxins:
- ETOH
- Cocaine
- Adriamycin
What toxins can result in CHF?
- EtOH
- Cocaine
- Adriamycin
Should CHF patients be on ACE inhibitors?
Yes
What is the MOA of Beta-blockers in CHF?
- Improve relaxation
- Protect myocardium from catecholamines
- Negative chronotrope
- Decrease O2 demand
- Increase beta-receptor density
What response do natriuretic peptides cause in the body?
Na and H2O diuresis
(counter the RAAS system)
Shock
Patient has mild hypotension, tachycardia, and tachypnea. There is also an increase in the anion gap. In what stage of shock is the patient? How effective is treatment?
- Stage I
- Compensated
- Treatment is most effective in this stage
Patient appears cool, cyanotic, and diaphoretic. He has hypotension, tachycardia, and tachypnea. He also has a decrease in urine output. In what stage of shock is the patient? How effective is treatment?
- Stage II
- Compesatory mechanisms begin to break down
- Aggressive therapy can reverse changes
Patient is found to have hypotension, tachycardia, and tachypnea. There are also signs of end organ damage and DIC. In what stage of shock is the patient? How effective is treatment?
- Stage III
- Irreversible
- Therapy is not effective
What is the cause of acidosis in shock? What problems result? What are the corrective measures?
- Cause:
- anaerobic metabolism
- Toxins
- Result:
- alters oxy-hemoglobin dissociation
- Hypoxia worsens
- Corrective measures:
- Add buffer (NaHCO3)
- Correct respiratory component
What type of shock is characterized by a low CO and a high SVR? What is the cause?
- Cardiogenic shock
- Cause: cardiomyopathy
- Volume replacement makes worse
- Hypovolemia
- hemorrhage
- dehydration
- fluid loss due to injury or burns
- Volume replacement makes better
What type of shock is characterized by a decreased SVR and a CO that may be normal, high, or low?
Septic Shock
Patient has a low CO and a high SVR. Volume replacement worsens the problem. Which type of shock is this?
Cardiogenic shock
Patient has alow CO and a high SVR. Volume replacement fixes the problem. Which type of shock is this?
Hypovolemia
When can pressor support be used in the treatment of shock?
Only once hypovolemia is corrected
Pulmonary Hypertension
What is the effect of an increase in length of the vessel on vascular resistance?
Resistance will increase proportionately
What is the effect of an increase in viscosity of blood on vascular resistance?
Resistance will increase proportionately
What is the effect of an increase in radius of the vessel on vascular resistance?
The resistance will decrease (by a power of 4)
Ex: radius increases by a factor of 2, resistance will decrease by a factor of 16
In pulmonary HTN, how is the intima and media changed?
- Intima:
- hyperplasia
- Media
- Hypertrophy
- Also interstitial fibrosis occurs
What is Eisenmenger’s Syndrome? What is the result?
- Eisenmenger Syndrome
- A previously L => R shunt changes to a R => L shunt
- often due to increased pulm pressure from overload and damage
- A previously L => R shunt changes to a R => L shunt
- Result
- Fatal (lack of oxygenation)
What is the result of Cor Pulmonale?
RV failure
In pulmonary HTN, how is JVP affected?
- Large a wave
- Prominent v-wave
What murmurs are common with Pulm HTN?
- Closely split S2 with loud P2
- PA click and murmur
- RV S3 gallop
What changes in the carotid occur with Pulm HTN?
Low volume
(blood stuck in veins)
What laboratory abnormalities can be found in Pulm HTN?
- Polycythemia
- response to hypoxia
- Increased liver function tests
- response to congestion of liver
What ECG findings occur in Pulm HTN?
- Right axis deviation
- R atrial abnormalities
- LV hypertrophy
How is primary Pulmonary Hypertension diagnosed? What population is most affected? What are the symptoms?
- Diagnosis
- exclusion of other possibilities
- Population
- young women
- Symptoms
- Chest pain
- Loud P2
- Dyspnea on exertion
What is the best treatment for Cor Pulmonale?
O2
Cardiomyopathy
Dilated cardiomyopathy results in dysfunction of what cardiac mechanism?
Contraction
(systole)
What causes dilated cardiomyopathy?
- EtOH
- Cobalt
- Uremia
- Hypocalcemia
- Hypophosphatemia
Hypertrophic cardiomyopathy results in dysfunction of what cardiac mechanism?
Filling
(diastole)
What causes hypertrophic cardiomyopathy?
- Genetics
- Abnormal sympathetic stimulation
- Ischemia (coronary artery disease)
- Collagen abnormality
What are the clinical manifestations of hypertrophic cardiomyopathy?
- Dyspnea
- Angina pectoris
- Fatigue
- Syncope
- Palpitations
What murmurs can be present with hypertrophic cardiomyopathy?
- S3 gallop
- S4 gallop
- Systolic crescendo - decrescendo murmur
- Systolic thrill
- Mitral regurg (if systolic anterior motion is present)
***Best heard at apex
Treatment of HCM is focused on trying to change what cardiac characteristics?
- Decrease contractility
- Increase ventricular compliance
- Increase ventricular volume
- Increase systemic arterial pressure
- Increase dimensions of outflow tract
What pathophysiological signs are present in restrictive cardiomyopathy? What forms of cardiac dysfunction result?
- Myocardial fibrosis
- Hypertrophy
- Infiltration
This causes:
- Excessively rigid ventricular walls
- Abnormal diastolic function
- impeded ventricular filling
- Abnormal systolic function
What are the clinical manifestations of restrictive cardiomyopathy?
- Weakness and fatigue
- Increased central venous pressure
- JVD
- Peripheral edema
- Ascites
- Anascara
- Inspiratory increase in venous pressure
- aka Kussmaul’s sign
What is Kussmaul’s sign?
An inspiratory increase in venous pressure
(present in Restrictive Cardiomyopathy)
What causes restrictive cardiomyopathy?
- Amyloidosis
- Sarcoidosis
- Inherited infiltrative diseases
- Endomyocardial disease
What are the causes of myocarditis?
- Infectious
- most common is Coxsackie A and B
- Toxic
- Chemical
- Drugs
- Physical Agents
Not more specific than that in ppt
A patient has a history of prodromal “flu”. Which type of pericarditis is most likely? How can this be confirmed?
- Viral pericarditis
- Cocksackie A or B
- Echovirus
- EBV (mono)
- Confirmation
- Viral titers
Patient with pericarditis has been on dialysis. What is the most likely cause of the pericarditis? What complication can result?
- Cause:
- Uremia
- Complication
- Hemodynamic instability
What type of MI is most likely to cause pericarditis? How long post-MI is it most likely to occur?
- Type:
- Transmural MI
- Time frame
- 2-3 days post-MI
- May have atrial arrhythmias
Which cancers are most likely to cause pericarditis?
- Bronchogenic
- Breast
- Lymphoma
- Leukemia
- Melanoma
What symptoms commonly occur with pericarditis?
- Chest pain
- Pleuritic
- Dyspnea
- Fever
What findings on physical exam indicate acute pericarditis?
- Friction rub
- Tachycardia
- Increased JVP
- Pulsus paradoxus
- large decrease in systolic BP on inspiration
What is the differential diagnosis for the signs and symptoms of Acute Pericarditis?
- Acute MI
- Pneumonia with Pleuritis
- Acute pulmonary embolism
- Chest trauma causing Pneumothorax
- GI disturbance
What are the clinical manifestations of Cardiac Tamponade?
- Physical exam:
- Beck’s Triad:
- Hypotension
- Elevated venous pressure
- Small, quiet heart
- Pulsus paradoxus
- Tachycardia
- Tachypnea
- Beck’s Triad:
- History:
- Chest pain
- Dyspnea
What is found on ECG for a patient with cardiac tamponade?
- ST elevation (pericarditis)
- Electrical alternans
- alternation of QRS complex amplitude oraxis between beats and a possible wandering base-line
- Low voltage
Which part of the heart cycle is affected by constrictive pericarditis?
Diastole
(Restricted filling of the heart)
What are some causes of constrictive pericarditis?
- TB
- Uremia
- Irradiation
- Surgery
- Connective tissue disorders
- Cancer
What are the clinical features of Constrictive Pericarditis?
- Diastolic pericardial knock
- Elevated venous pressure
- Edema
- Hepatomegaly
- Ascites
- Elevated jugular venous pressue (Kussmaul’s sign)
- Elevated left heart pressure
- Dyspnea
- Cough
- Orthopnea
- Low cardiac output
- Fatigue
What are the differences in signs and symptoms between cardiac tamponade and constrictive pericarditis?
Congenital Heart Disease
Atrial septal defect
- Type of shunt
- Cyanotic?
- Complications
- Murmur
- ECG findings
- Method of diagnosis
- Type of shunt
- L => R
- Cyanotic?
- No
- Complications
- Asymptomatic thru mid adult life
- A-fib
- Murmur
- Systolic ejection murmur: upper LSB
- Persisten split of S2
- ECG findings
- RV conduction delay
- Method of diagnosis
- Echo
Ventricular Septal Defect
- Type of shunt
- Cyanotic?
- Complications
- Murmur
- ECG findings
- Method of diagnosis
- Type of shunt
- L => R
- Cyanotic?
- No
- Complications
- Infective endocarditis
- Heart Failure
- Murmur
- holosystolic murmur at lower LSB and apex
- ECG findings
- LV enlargement
- Method of diagnosis
- Echo and Doppler
Patent Ductus Arteriosus
- Type of shunt
- Cyanotic?
- Complications
- Murmur
- Type of shunt
- L => R
- Cyanotic?
- No
- Complications
- Infective endocarditis
- LV failure
- Murmur
- Machine murmur
- Bounding pulse
- Wide pulse pressure
*
Eisenmenger Syndrome
- Type of shunt
- Cyanotic?
- Type of shunt
- R => L
- previously L => R, but reversed due to pulm HTN
- Cyanotic?
- Yes
Coarctation of the Aorta
- Definition
- Presentation
- Consequences
- Definition
- stenosis of aorta
- No shunt or cyanosis
- Presentation
- Upper body HTN
- Consequences
- Aortic rupture or dissection
- Heart Failure
- Infective endocarditis
- Cerebral hemorrhage
Tetrology of Fallot
- Definition
- Presentation
- Definition
- Pulmonary stenosis
- VSD
- Transposed aorta
- RV hypertrophy
- Presentation
- Cyanotic
- Dyspnea
- Squatting
- increases systemic bp to force more blood into pulm circulation
Ebstein’s Anomaly
- Definition
- Consequences
- Definition
- Abnormal tricuspid valve (displaced into RV)
- Pulm or aortic valve stenosis
- Consequences
- May be asymptomatic until adulthood
- (doesn’t describe consequences specifically)
Transposition of the Great Vessels
- Consequence
Cyanosis
Must have other defect to serve as a shunt between the sides of the heart
