congenital heart disease

Pt presents with failure to thrive,

PE shows hepatomegaly, murmur, tachypnea. use of accessory muscles, diminished air entry and inspiratory crepitation at the lower zones bilaterally.

symptoms of congestive heart failure in an infant

digoxin, diuretics (furosemide), ACEI’s

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_{the reason behind the answer:}

_{Think: “Remove fluid + help the heart pump + reduce afterload + fix the cause.”}

Treatment	Purpose
⭐ Furosemide	Diuretic → ↓ pulmonary/systemic congestion
⭐ ACE inhibitor (captopril/enalapril)	↓ Afterload → heart pumps forward more easily
Digoxin	↑ Contractility; sometimes used in selected infants (+iontrope) ❤ squeezes more, beats less
O₂ / respiratory support	If hypoxemic or in respiratory distress
High-calorie feeds	Infants with CHF have ↑ energy needs and tire during feeds
Treat underlying cause	e.g., repair significant VSD/PDA/other congenital defect

management of infantile congestive heart failure (3)

premature atrial beat

-usually asymptomatic, pt may notice pauses or nonconducted beat followed by strong beat

-abnormal P wave

-P wave looks different because the impulse originates from an ectopic atrial focus (upper chambers), not the SA node

EKG: Narrow QRS complex w/ preceeding P wave

reduce triggers like smoking and caffeine

± low dose Bblocker.

*may increase risk of afib/flutter

management of premature atrial beats

1st degree AV block

abnormal prolongation of PR interval (> 200 milliseconds).

every P wave followed by QRS complex

• (no blocked or nonconducted P waves)

type I (Mobitz I) second degree AV block

_{“think going,,, going,, drop”}

progressive lengthening of PR interval until wave is not followed by conducted QRS complex

(variable RR, regulary irregular)

rx: usually none. asymp.

Mobitz I (Wenckebach)

What type of second degree AV block is associated with the following?

-PROGRESSIVE PR interval

-dropped QRS complex

-shortened R-R interval

Mobitz II second degree AV block

_{(note: this may progress to a 3rd degree block as it usually indicates structural problem (ischemia/fibrosis))}

_±pacemaker

Sudden nonconduction of P wave with loss of QRS complex without progressive PR interval lengthening

Mobitz Type II

- Dropped beats that are not preceded by a change in the length of the PR interval

- Often found as a 2:1 block, where there are 2 or more P waves to 1 QRS complex.

- Treatment: ± pacemaker

3rd degree AV block

• P waves & QRS complexes are dissociated

• absence of AV conduction characterized by complete dissociation (AV dissociation) of atrial and ventricular activity _{( beat independent of ea other)}

• atrial rate > ventricular rate

• rx: pacemaker for sure!

• _{fun fact: can be caused from Lym3 dz}

• discontinue affecting meds,

• atropine, beta 1 agonists (incr ❤ rate)

• pacemaker

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_{the reason:}

Heart block	Management	Why?
1st-degree AV block	Usually observe	Every impulse still reaches ventricles; just delayed
Mobitz I (Wenckebach)	Usually observe; atropine / B1 if symptomatic bradycardia	Usually an AV-node problem → atropine increases AV-node conduction
Mobitz II	± Pacemaker	Block is usually below AV node (His-Purkinje) → atropine unreliable; can progress to complete block
3rd-degree (complete)	Pacemaker	Atria and ventricles are completely dissociated; atropine often ineffective

Drug	Mechanism	Result
Atropine	Blocks M2 parasympathetic activity	⭐ ↑ HR + ↑ AV conduction
β₁-agonist (e.g., isoproterenol/epinephrine)	Stimulates cardiac β receptors → ↑ cAMP	⭐ ↑ HR + ↑ contractility/conduction

management of heart blocks

long QT syndrome

asymptomatic

or

present with palpitations, syncope, or cardiac arrest.

• >450-480ms QT interval on ECG

• increased risk for ventricular arrhythmia

Long QT but stable/cong. → β-blocker

Long QT from medication → stop the medication + correct electrolytes

Long QT → torsades → IV MAGNESIUM

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Syndrome	Inheritance	Key feature
Romano-Ward syndrome	Autosomal dominant	Long QT without deafness
Jervell and Lange-Nielsen syndrome	Autosomal recessive	Long QT + congenital sensorineural deafness

For boards, remember these big ones:

• Macrolides → ⭐ azithromycin, erythromycin, clarithromycin

• Fluoroquinolones → levofloxacin, moxifloxacin

• Antipsychotics → ⭐ haloperidol, ziprasidone

• Antidepressants → citalopram, escitalopram, TCAs

• Antiarrhythmics → Class IA (quinidine, procainamide) + Class III (sotalol, dofetilide, amiodarone)

• Antiemetics → ⭐ ondansetron

• Methadone

🧠 Board shortcut

“Antibiotics + psych meds + antiarrhythmics + Zofran” → think QT prolongatio

management of long QT syndrome

if stable/congential:

if from meds:

torades:

sinus arrhythmia

is an irregular heartbeat that's either too fast or too slow

respiratory sinus arrhythmia

when the heartbeat changes pace when you inhale and exhale. In other words, your heartbeat cycles with your breath.

> 220 beats per minute for infants

> 180 beats per minute in children and adolescents.

supraventricular tachycardia rate

(infants // kids,teens)

can be asymptomatic with tachycardia, may have symptoms of arrhythmias such as palpitations, lightheadedness, or syncope

symptoms of SVT

Supraventricular tachycardia

Rapid heart rate originating above ventricles.

most common: reentry b/t atrium & ventricle in the AV node

if unstable, cardioversion.

If stable, vagal stimulation, adenosine.

definitive: cath ablation of reentry tract

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Adenosine:

MOA: activates A1 (Gi) receptors in the AV node → ↓ cAMP → ↑ K⁺ efflux → transiently blocks AV-node conduction.

Think: Adenosine briefly “pauses” the AV node → breaks the SVT circuit.

• Use: Stable, regular narrow-complex SVT after vagal maneuvers

• Administration: Rapid IV push because half-life is <10 seconds

• Common effects: flushing, chest discomfort, dyspnea, brief sense of impending doom

• Avoid/caution: asthma/bronchospastic disease → can cause bronchospasm

management of SVT

(unstable v stable)

ventricular premature beats

• wide QRS complex with no preceding P wave.

• ectopic extra heartbeats that begin in one of the heart's two lower pumping chambers (ventricles).

• shorten’d diastolic filling time (lower SV than normal)

• These extra beats disrupt the regular heart rhythm, sometimes causing a sensation of a fluttering or a skipped beat in the chest.

usually not a concern unless very frequent or bothersome

associated with underlying heart cond.

management of ventricular premature beats

ventricular tachycardia

A rapid heart rhythm in which the electrical impulse begins in the ventricle (instead of the atrium), which may result in inadequate blood flow and eventually deteriorate into cardiac arrest.

typically regular rhythm, HR >100

Sustained V-tach lasts more than 30 seconds

define a sustained v-tach that causes serious health problems

Wolff-Parkinson-White Syndrome (WPW)

an electrocardiography (ECG) finding that indicates ventricular preexcitation due to antegrade conduction over an accessory pathway, reentry of circuit.

Wolff-Parkinson-White Syndrome

_{(WPW = “Wolf takes a shortcut” → Bundle of Kent bypasses the AV node → ventricles activate too early → short PR + delta wave.)}

delta wave and shortened PR interval

• Often asymptomatic

• can have:

• Episodic palpitations

• Tachycardia

• Dizziness/syncope

• Can present with SVT

presentation of WPW

-PDA

-ASD

-VSD

-endocardial cushion defect (AV canal)

-coarctation of the aorta

congenital heart defects that are left to right shunts

(pink babies)

24-48 hours

when does ductus arteriosus typically close?

prematurity and congenital rubella

pts with an increased incidence of PDA

patent ductus arteriosus

continuous systolic machinery murmur heard best in left clavicular region often radiating to the left back

-widened pulse pressure

-bounding pulse

-initially with diuretics and supportive

-closuure: indomethacin or catheter

treatment of PDA

down syndrome, fetal alcohol syndrome

ASD has an increased incidence in

-small: failure to thrive and decreased exercise tolerance

-large--> pulmonary edema and right sided heart failure

common symptoms of ASD

ASD

Loud S1, fixed split S2

-systolic ejection murmur at L sternal border

-shunting rarely occurs, but there is a risk of embolization via PFO to systemic circulation

risk associated with PFO

down syndrome, fetal alcoholl syndrome, gestational diabetes

there is an increased incidence of VSD in pts with

-typically asymptomatic at birth

-at 6-8 wks of life, pulmonary vascular resistance decreases which increases L-->R shunting

-present with fatigue, poor growth, diaphoresis

presentation of VSD

VSD

holosystolic murmur best heard at the LLSB

-1/3 close spontaneously

-initial tx: diuretics, digoxin and afteerload reduction

treatment of VSD

endocardial cushion defect

aka: atrioventricular septal defect (AVSD) or AV canal defect.

-abnormal development of endocardial cushions

• Failure of the endocardial cushions to fuse

• → defects in the lower atrial septum + upper ventricular septum

• → abnormal AV valves (mitral/tricuspid)

• Causes a left → right shunt → pulmonary overcirculation → CHF

associated with down syndrome (21)

initial mgmt is diuretics to reduce afterload

-surgical repair is requiredd

management of endocardial cushion defect

-turner's syndrome

-boys>girls

increased incidence of coarctation of the aorta in

coarctation of the aorta

-harsh systolic ejection murmur

-weak or absent femoral pulses; HTN of upper extremities

rib notching

CXR findings of coarctation of the aorta

-initial: PGE1 and diuretics

-cardiac catheter with ballooning

-open surgery

treatment of coarctation of the aorta

-truncus arteriosus

-persistent pulmonary HTN

-transposition of the great vessels

-TOF

-tricuspid atresia

-total anomalous pulmonary venous return

list the Right to Left shunts

Persistent Pulmonary Hypertension of the Newborn (PPHN)

-failed transition from fetal state of undilated, high resistance in the pulmonary blood vessels

-Right to left shunt

-hypoxia during birth, meconium aspiration, neonatal pneumonia, infectioin, anemia, gestational DM, gestational HTN

-maternal use of SSRI or large amounts of aspirin

persistent pulmonary HTN is most common in term infants with

-develop immediately after birth

-resp distress, tachy, hypotension, pallor, cyanosis

symptoms of PPHTN of the newborn

persistent pulmonary HTN

-preductal O2 saturation higher than post ductal

-single loud S2

-harsh systolic murmur

-oxyen (dilates)

-electrolyte and nutritioni support

-inhaled NO

tx of persistent pulmonary HTN

truncus arteriosus

-truncus never completely separates into the aorta and pulmonary arteries--->one great vessel with a single valve

transposition of great arteries

most common cyanotic heart disease to present in the NEWBORN

-aorta connects to the RV

-pulmonary artery connects to LV

-survival depends on havin a mixing lesion

describe the defect of TGA

Transposition of the great vessels

-infant cyanotic from birth (as soon as ductus starts to close)

-unresponsive to O2

-tachypnea, clubbbing

CXR: egg on a strong appearance

CXR findning of TGA

-PGE1 to keep ductus patent (alprostadil)

-surgery within first week

treatment of TGA

Tetralogy of Fallot

most common cyanotic CHD

pulmonic stenosis--> RV hypertrophy

-large VSD

-overiding aorta

4 defects of TOF

overriding aorta

A congenital heart defect where the aorta is positioned directly over a ventricular septal defect (VSD), instead of over the left ventricle.

-high pitched systolic ejection murmur

auscultation of TOF reveals

-decreased SVR (dehydration) or increasedd RVOT obstruction (crying or tachycardia)

what causes tet spells?

-upturned cardiac apex (boot shaped heart)

CXR finding of TOF

-PGE1

-beta blocker while awaiting surgery

-surgery is definitive tx

treatment of TOF

Tricuspid Atresia

-endocardial cushions fail to form tricuspid valve

-hypoplastic R ventricle

-ASDD or PFO and VSD reqiured for survival

single S2 with holosystolic murmur

murmur associated with tricuspid atresia

surgery is palliative, not curative

prongosis of tricuspid atresia

Total anomalous pulmonary venous return

pulmonary vein return blood to the right side of the heart not the left

snowman's sign on CXR

CXR sign of total anomalous pulmonary venous return

Double-outlet right ventricle (DORV)

both great arteries connect to the right ventricle

R-->L shunt

Hypoplastic Left Heart Syndrome

most common cardiac defect to cause death in first month of life

-hypoplastic lefft ventricle

-stenotic or no mitral valve

ebstsein's anomaly

associated with maternal lithium use, can present at any age

Ebstein's anomaly

Tricuspid flaps fused to inside of right ventricle; creates constant opening between atrium & ventricle

Ebstein's anomaly

CXR shows a very, very large heart and decreased pulmonary vascular markings

Hx and clinical exam

ECG

Chest xray

Echo

first steps in evaluation of congenital heart disease

Idiopathic

(often viral myocarditis — Coxsackie B, adenovirus),

genetic mutations,

toxins (alcohol, chemo: doxorubicin),

metabolic,

postpartum

frequent causes of dilated cardiomyopathy

dilated cardiomyopathy

_{systolic heart failure → weak, enlarged heart → ↓ ejection fraction.}

• Systolic dysfuntion(ventricle cannot pump) causing biventricular CHF. Mitral and Tricuspid Regurgitation due to stretching of the walls.

• In infants/children:

  • ⭐ Tachypnea / respiratory distress

  • ⭐ Poor feeding

  • ⭐ Diaphoresis (sweating) with feeds

  • Poor weight gain / failure to thrive

  • Fatigue, exercise intolerance in older children

  • Tachycardia

  • Hepatomegaly

  • Pulmonary crackles/congestion

  • Peripheral edema can occur but is less prominent in infants

  Exam: displaced PMI, S3 gallop, possible mitral regurgitation murmur.

-cardiomegaly, S3, elevated jugular venous pressure

physical exam findings of dilated cardiomyopathy

Genetic (AD — sarcomere protein mutations), idiopathic, sometimes secondary to storage diseases

causes of hypertrophic cardiomyopathy

Exertional dyspnea,

chest pain, syncope (esp. post-exertion),

S4 gallop, harsh crescendo-decrescendo murmur

↑ with Valsalva/standing, ↓ with squatting

sx off hypertrophic cardiomyopathy

-amyloidosis, post radiation, post op, diabetes

causes of restrictive cardiomyopathy

Treat HF (ACE-I/ARB, β-blockers, diuretics),

avoid CCB in systolic dysfunction,

ICD if EF ≤ 35%

management of dilated cardiomyopathy

dilated cardiomyopathy

Most common cardiomyopathy overall; in children, often post-vira

Avoid dehydration; β-blockers or non-DHP CCB (verapamil) to ↓ HR and improve filling; avoid vasodilators and high-intensity exercise; ICD if high risk

treatment of hypertrophic cardiomyopathy

hypertrophic cardiomyopathy

Leading cause of sudden cardiac death in young athletes