Cardiology Flashcards
What type of block is this?
Complete heart block
Findings include bradycardia for age and lack of correlation between the P wave and QRS complex. Because the impulse is blocked, an accessory junctional pacemaker typically activates the ventricles. This is known as a junctional or ventricular escape rhythm.
What type of heart block is this?
First-degree atrioventricular block
PR interval greater than normal for age (normal ranges from 100 to 160 msec in the infant and 140 to 180 msec in the adolescent/adult)
NOT associated with bradycardia
What type of heart block is this?
Second-degree atrioventricular block has two forms: In both a P wave is blocked from initiating a QRS complex.
Type 1 second-degree atrioventricular block is also known as Mobitz I is characterized by progressive prolongation of the PR interval on EKG on consecutive beats followed by a blocked P wave (ie, a dropped QRS complex) After the dropped QRS complex, the PR interval resets and the cycle repeats. This is almost always a benign condition for which no specific treatment is needed.
Type 2 second-degree atrioventricular block or Mobitz II is almost always a disease of the distal conduction system (His-Purkinje system). Mobitz II heart block is characterized on EKG by intermittently nonconducted P waves not preceded by PR prolongation and not followed by PR shortening (bottom pic). The medical significance of this type of atrioventricular block is that it may progress rapidly to complete heart block.
When do you see rapid rising or bounding pulses?
- Large PDA
- Aortic insufficieny
When do you hear systolic ejection clicks?
Midsystolic click at apex?
- Thickened/abnormal valve: aortic stenosis, bicuspid aortic valve, truncus arteriosis
- Enlarged aorta (TOF)
- MVP
When do you hear wide, persistent S2 splitting?
What is causing the splitting?
ASD, RBBB, pulmonic stenosis
Delayed right ventricular emptying
Systolic innocent murmurs: get ___ when supine, exercise, fever; get ____ with valsalva.
LOUDER because stroke volume increases: SOFTER with valsalva ( if louder thick HCM or obstructive left heart lesion!)
Describe Still’s murmur.
systolic ejection murmur with musical quality or vibratory character; heard best in lower precordium (NOT in the back)
Decreases with decreased venous return (standing, expiration)
Describe murmur heard with physiologic peripheral pulmonic stenosis (PPPS).
- soft, harsh systolic ejection murmur heard in both axillae and right/left upper chest.
- from turbulence in small right/left pulmonary arteries.
- usually gone by 12mo when branch arteries are larger
What causes venous hum murmur?
Blood draining down collapsed jugular veins into dilated intrathoracic veins
Goes away when patient supine (veins distended, no pressure gradient), valsalva, turning head, or compressing jugular vein.
Single mutant gene syndromes: What is the associated cardiac abnormality?
- Noonan syndrome
- Apert syndrome
- Holt-Oram syndrome
- Alagille syndrome
- Ellis-van Creveld syndrome
- Pulmonic stenosis, HCM
- VSD, Coarc
- ASD/VSD
- Pulmonic stenosis
- Single atrium
Chromosomal abnormalites: What is the associated cardiac abnormality?
- Cri-du-chat syndrome
- Turner syndrome (XO)
- Trisomy 21
- Trisomy 18
- Trisomy 13
- VSD
- Bicuspid aortic valve, coarc
- Endocardial cushion defect
- VSD
- VSD
Where do most VSDs occur in children < 1 year old?
> 1 year old?
muscular septum
membranous septum (below tricuspid and aortic valves)
Jones criteria for Rheumatic fever:
Minor and Major
Major
- carditis
- chorea
- subcutaneous nodules
- polyarthritis
- erythema marginatum
Minor
- arthralgia
- increased ESR
- prolonged PR interval
- fever
- increased CRP
How do you diagnose Rheumatic Fever?
- 2 major criteria
OR
- 1 major + 2 minor criteria
* *AND** - evidence of recent or concurrent GAS infection
What are 2 common murmurs heard in acute rheumatic fever?
- Care Coombs murmur: mitral regurg
* soft, mid-diastolic; heard only at apex - Austin Flint murmur: aortic regurg
* mid-diastolic apical murmur (MV opened by jet of aortic insufficiency)
*S1= closure of tricuspid and mitral valves (AV valves)
*S2 = closure of aortic, then pulmonic valve (physiologic splitting with inspiration= increased RV volume–> delayed emptying–>delayed closure of pulm valve)
When would you see right axis deviation (RAD) on EKG?
- RVH (which can be normal in newborn)
- ASD
- TOF
- Pulm HTN
When would you see left axis deviation (LAD) in EKG?
- Tricuspid atresia
- AV canal defects
- LVH
Lead 1+ and aVG - = __ axis deviation
Lead 1 - and aVG + = __ axis deviation
LEFT ( 1 looks like l)
RIGHT
**If both + = normal EKG**
Quick way to count heart rate on EKG…
What are the set of triplets to remember?
300-150-100
75-60-50
Count number of big sqaures between R-R intervals:
- 1 square = 300
- 2 squares = 150
- 3 sqaures = 100…
What is normal PR interval?
120-200 ms
What is the PR interval in 1st degree AV block?
What is the PR interval in WPW?
> 200ms (1 big square)
< 120 ms (3 small squares) with delta wave
What is a normal QT interval range?
340-440 ms
What syndromes associated with prolonged QT and sensorineural deafness?
Jervell
Lange-Nielsen
What prescribed drug may cause prolonged QT
Tricyclics
(think about depressed adolescent)
Prolonged QT can be seen in what electrolyte abnormalites?
- Hypocalemia
- Hypomagnesemia
- Hypokalemia
Think “proLOWnged QT”
Short QTc can be seen in what?
- Hypercalcemia
- Digitalis
What will you seen on EKG for right atrial enlargement?
Left atrial enlargement?
RAE: Peaked P waves in leads II and V1
LAE: broad, negative P wave in V1 or
notched “M” shaped P wave in II
When do you find peaked T waves?
- Hyperkalemia
- Intracerebral hemorrhage
What is U wave and where is it seen?
What does prominent U wave predict?
When would you see prominent U waves?
Occurs just after T wave and best seen in V2-V3
torsades de pointes (polymorphic v-tach that can progress to v-fib)
- hypokalemia
- digitalis
- amiodarone
- bradycardia
ST segment elevation is seen in what?
ST segment depression is seen in what?
Pericarditis
- Hypokalemia (low = depressoin)
- Digitalis
(you can see U waves in both of these too!)
How does LVH present on EKG?
Lead V5 and V6 with have spiked +R waves >95th percentile
What condition would you see “rabbit ears” on EKG?
RBBB
can see RR’ (rabbit ears) in V1
What is the treatment for atrial flutter?
synchronized electrical cardioversion
low energy= 0.5J/kg
high energy = 1-2J/kg (often used bc it has less tendency to convert the rhythm to afib)
What antiarrthymic drugs can you use for NONemergent conversion of atrial flutter?
SLOW the rate:
- Diltiazem IV
- Digoxin IV
- Beta-blocker IV
Attempt CONVERSION:
- Procainamide
- Sotalol
- Amiodarone
Prevent recurrence:
- Quinidine
- Flecainide
- Sotalol
- Dofetilide
- Amiodarone
What is WPW?
Pre-excitation syndrome: PR interval < 120ms due to delta wave
Many patients asymptomatic
What is the drug of choice for infant with WPW who develops afib or a-flutter?
IV procainamide
Radiofrequency ablation = treatment of choice for children with SVT and WPW
For which patients should you NOT use verapamil to slow the heart rate?
- Young infants (< 1yo)
- Afib in WPW (increases transmission in bypass bundle which can lead to Vfib and/or sudden death)
- Atrial flutter
- Wide complex tachycardias (usually seen in WPW)
- Beta-blockers (both (-) inotropes and chronotropes)
List the MOA for each class of antiarrhythmic drug:
Class I
Class II
Class III
Class IV
Class I: slows conduction by blocking sodium channels
Class II: decreases sympathetic activity
Class III: prolongs action-potential duration
Class IV: calcium channel blockers
What is acute side effect of Adenosine?
Bronchoconstriction; may need to use bronchodiator
What are major side effects of Class I antiarrhymics?
Ia: Quinidine, Procainamide
Ib: Lidocaine
Quinidine
- prolongs QRS and QT interval…torsades de pointes
- diarrhea
- autoimmune thrombocytopenic purpura
- “Cinchoism”: hearing loss, tinnitus, psychosis
Procainamide
- prolongs QRS and QT
- agranulocytosis, neutropenia, thrombocytopenia
- drug-induced lupus
- do not use in cardiac failure patient! (mild, myocardial depressive effect)
Lidocaine
- seizures
What are major side effects of Class II antiarrhymics?
Class III?
Beta-blockers (Class II)
- bradycardia
- aggravates asthma
Bretylium (Class III)
- transient HTN
- postural hypotension
Amiodarone (Class III): extremely high iodine content: do NOT use chronically in kids without close f/u
- corneal deposits
- pulmonary fibrosis (rare in children)
- gray skin
- hyper/hypothyroidism
- hepatic toxicity
- sun sensitivity
What is major side effect of Digoxin?
How do you determine toxic levels?
Arrhythmias
EKG (not serum levels)
What type of VSDs do you treat medically?
- Muscular VSDs since they are more likely to decrease in size
- Therapy includes diuretics, afterload reducers, and/or Digoxin
- if not smaller by 1yr, consider surgery between 1-3yo
What is the most common ASD
Ostium secundum defects (located mid-septum)
What is heard with ASD?
Normal S1 with fixed, widely split S2
Kids usually asymptomatic, but pulm HTN and/or arrhythmias can occur (~5%) at age 20-30; surgical intervention is usually indicated to prevent arrhythmias
When are the only instances in which antibiotic prophylaxis is recommended?
Dental, respiratory, and infected skin procedures ONLY in the presence of:
- prosthetic cardiac valve
- previous h/o endocarditis
- heart transplant recepients with valvulopathy
- unrepaired cyanotic heart disease
- completely repaired CHD with prosthetic material or device x 6 mo post-procedure
What SBE (subacute bacterial endocarditis) prophylaxis regimen would you recommend for someone allergic to PCN?
What if allergic AND unable to take oral meds?
Standard ppx: Amoxil 50mg/kg po 1 hour before (max 2g)
Unable to take oral: Amp 50mg/kg IV/IM within 30 mins (max 2g)
Allergic to PCN: Clinda 20mg/kg po 1 hr before (max 600mg) or Keflex 50mg/kg po 1 hr before (max 2g) or Azithro/clarithromycin 15mg/kg po 1 hr before (max 500mg)
Allergic to PCN and unable to take oral: Clinda 20mg/kg IV within 30 mins before (max 600mg) or Cefazolin 25mg/kg IV/IM within 30 mins before (max 1 g)
(NO post-procedure doses!!)
By what age will heart failure occur in most children with complete AV canal defects?
2 months
CAVC results in large left-to-right shift and valve regurge, leading to volume overload and CHF.
Early surgery is necessary, within first 6-12 mo to prevent pulmonary vascular dz (Eisenmenger’s)
Children with Down’s usually have a good chance of having a compatible anatomy for correction.
What is the Austin Flint murmur? What disease is it associated with?
Low-pitched, mid-diastolic murmur at the apex due to aortic regurge jet striking mitral valve and preventing it from opening (causing relative “mitral stenosis”)
Associated with rheumatic fever
Describe the murmur heard with AR?
High-pitched, early diastolic murmur that begins with aortic component of S2
What are some causes of AR in children?
- congenital AS (insufficiency can develop over time)
- RF
- Marfans
- Infective endocarditis (especially from S.aureus)
Describe MR murmur. How is this different from MVP murmur?
apical, high-pitched, blowing systolic mumur
can radiate to axilla and the back
MVP murmur: mid-late systolic crescendo at the apex preceeded by a “click”); gets LOUDER when patient sits or stands (decreased LV volume)
If early systolic ejection murmur gets louder with standing… think HCM!
Worldwide, what is most common cause of MR? In the U.S.?
Worldwide- RF
U.S.- MVP (1-5% of population)
What is the 2nd most common congenital cardiac lesion? Describe the murmur.
Pulmonic stenosis
Murmur: systolic ejection click (varies with respiration) along left sternum followed by crescendo-decrescendo murmur
Consider treatment in these patients:
- symptomatic with exercise
- signifiacnt RVH
- RV systolic pressure > 50mmHg or 50% of systemic pressure
What genetic disorders are associated with pulmonic stenosis?
Alagille syndrome (PV or peripheral stenosis)
**Noonan syndrome **
How will infant present with AS?
What is the murmur of an older child with AS?
Baby:
- systolic murmur and R/L upper sternal border with early ejection click
- diminished perfusion and pulses…can look like septic shock
Older children:
- murmur is crescendo-decrescendo harsh systolic murmur (louder with squatting)
- suprasternal notch thrill
- paradoxical splitting (aortic component of S2 is delayed)
- can hear 3rd heart sound at apex
- if symptomatic, will need cardiac cath
- Balloon valvoplasty = treatment of choice
What is the classic xray finding in a 7yr old with undiagnosed coarc?
- aortic segment just above coarch can look like the “3” sign
- rib notching at lower rib margins due to erosion of bone by large intercostal arteriies
Describe HCM murmur.
- crescendo-decrescendo systolic mumur
- S3 and S4 common
- gets louder with standing or Valsalva (dec venous return = dec LV volume)
- gets softer with squatting (inc LV volume causes heart to stretch and will dec murmur)
What is therapy for HCM?
- Most die from arrthythmias
- Amiodarone is only drug shown to improve mortality (but has toxic S/E’s)
- some require surgical resection or implantable defibrillators
What arrhythmia is associated with Ebstein’s anomaly of the tricuspid valve?
WPW
