Clin Med I Exam 3

Anatomic malformation of the heart or great vessels occurring during intrauterine development

What is the definition of a congenital heart defect?

First trimester

During which trimester of pregnancy does maternal rubella infection present the highest risk for congenital heart defects?

Lithium

Which bipolar medication is a known teratogen associated with congenital heart malformations?

Accutane

Which severe acne medication causes fetal teratogenicity including congenital heart defects?

Depakote

Which anti-seizure medication taken during pregnancy increases the risk of congenital heart defects?

Fetal alcohol syndrome

What condition resulting from maternal alcohol abuse is associated with congenital heart defects?

Maternal diabetes, PKU, and folic acid deficiency

What maternal chronic diseases or deficiencies increase the risk of congenital heart defects?

Down syndrome

Which chromosomal disorder (Trisomy 21) is strongly associated with congenital heart defects?

Turner syndrome

Which chromosomal condition in females (XO) is commonly associated with congenital heart defects?

Defects with increased pulmonary blood flow or obstruction to ventricular outflow

How are acyanotic congenital heart defects classified pathologically?

Defects with decreased pulmonary blood flow or mixed blood flow

How are cyanotic congenital heart defects classified pathologically?

ASD, VSD, PDA, and AV canal defects

Which congenital heart lesions cause increased pulmonary blood flow?

Coarctation of the aorta, aortic stenosis, and pulmonary stenosis

Which acyanotic congenital heart lesions cause obstruction to ventricular outflow?

Tetralogy of Fallot and tricuspid atresia

Which cyanotic defects cause decreased pulmonary blood flow?

Transposition of the Great Arteries, TAPVR, Truncus Arteriosus, and Hypoplastic Left Heart Syndrome

Which cyanotic heart defects are characterized by mixed blood flow?

Left-to-right shunt

What direction of blood shunting occurs in acyanotic defects with increased pulmonary blood flow?

Opening in the atrial septum allowing oxygenated blood to flow from left atrium to right atrium

What is an Atrial Septal Defect?

Fusion of septum primum and septum secundum

What embryologic septa fuse to form the permanent atrial septum?

Septum primum

Which embryologic structure forms the valve flap covering the foramen ovale?

Increase in left atrial pressure after birth

What hemodynamic event after birth causes closure of the foramen ovale flap?

Failure of the septum primum and septum secundum to fuse

What structural failure results in a Patent Foramen Ovale?

Widely split and fixed S2

What classic cardiac auscultatory sign is pathognomonic for an Atrial Septal Defect?

Systolic ejection murmur

What murmur type is audible at the upper left sternal border in a significant ASD?

Right atrial and right ventricular enlargement

What cardiac chamber enlargements are visible on chest X-ray in a large ASD?

Prominent pulmonary artery segment and increased pulmonary vascular markings

What pulmonary signs appear on chest X-ray with a large left-to-right shunt?

Atrial flutter and atrial fibrillation

What atrial arrhythmias commonly develop in adults with untreated ASD?

Catheter-delivered septal occluder device

What is the preferred nonsurgical treatment for closing an Atrial Septal Defect?

Opening in the ventricular septum allowing blood flow from left ventricle to right ventricle

What is a Ventricular Septal Defect?

Ventricular Septal Defect

What is the most common overall congenital heart defect?

Extra volume in right heart leading to pulmonary hypertension and arterial thickening

What pulmonary vascular changes occur due to blood shunting in a VSD?

Holosystolic murmur at the lower left sternal border

What is the characteristic murmur associated with a Ventricular Septal Defect?

Poor feeding

What ominous sign in an infant with a large VSD indicates impending heart failure?

Loud single S2

What heart sound change occurs in VSD when severe pulmonary vascular disease develops?

Digital clubbing and cyanosis

What physical examination signs manifest when long-standing VSD causes shunt reversal?

LA, LV, and RV enlargement with pulmonary vascular congestion

What cardiomegaly pattern is seen on chest X-ray in a large VSD?

Increases RV pressure to prevent excess left-to-right pulmonary shunting

What is the goal of palliative pulmonary artery banding in VSD?

Surgical patch closure

What is the definitive surgical repair method for a Ventricular Septal Defect?

Persistent connection between the aorta and pulmonary artery

What is a Patent Ductus Arteriosus?

Ligamentum arteriosum

What anatomic structure does the ductus arteriosus become upon normal closure?

Maternal rubella during first trimester

What maternal viral infection is specifically associated with Patent Ductus Arteriosus?

Bounding peripheral pulses with wide pulse pressure

What peripheral pulse characteristics are observed in a patient with a large PDA?

Increased stroke volume and continuous runoff from aorta into pulmonary artery

Why does a large PDA cause bounding pulses and wide pulse pressure?

Continuous machinery murmur

What classic murmur is pathognomonic for a Patent Ductus Arteriosus?

Left infraclavicular area or upper left sternal border

Where is the continuous machinery murmur of a PDA best appreciated on auscultation?

Cyanosis isolated to the lower body

What differential cyanosis pattern develops if a PDA leads to right-to-left shunting?

Indomethacin

What pharmacologic agent is administered to promote closure of a PDA in premature infants?

Structural defect of ductal smooth muscle

Why do full-term infants rarely experience spontaneous closure of a PDA compared to preterm infants?

Large central defect separating all four chambers with a single shared AV valve

What is an Atrioventricular Canal Defect?

Down syndrome

Which genetic condition has the strongest clinical association with Atrioventricular Canal Defects?

Infant heart failure with edema, fatigue, wheezing, diaphoresis, and tachypnea

How does a complete Atrioventricular Canal Defect present clinically in newborns?

Septal patch closure and AV valve reconstruction

What surgical procedures are required for definitive repair of an AV Canal Defect?

Anatomic narrowing of the aorta, most commonly distal to the aortic arch

What is Coarctation of the Aorta?

Elevated blood pressure in arms with reduced or delayed blood pressure in legs

What hallmark finding is obtained from four-limb blood pressure measurements in coarctation?

Headaches from upper body hypertension and leg cramps from lower body hypoperfusion

What symptom complaints do older children with aortic coarctation present with?

Pallor, respiratory distress, weak thready pulses, oliguria, and severe acidemia

How does an infant with severe coarctation present during acute circulatory collapse?

Rib notching

What classic chest X-ray finding in aortic coarctation is produced by dilated intercostal collaterals?

Continuous intravenous Prostaglandin E1 infusion

What medical treatment reopens the ductus arteriosus to restore systemic flow in severe coarctation?

Resection of narrowed segment with end-to-end anastomosis

What is the primary surgical correction for Coarctation of the Aorta?

Narrowing of the aortic valve causing LV outflow tract resistance

What is Aortic Stenosis?

Malformed valve cusps

What is the most frequent anatomic cause of pediatric valvular aortic stenosis?

Exertional chest pain, fatigability, and syncope

What severe symptoms indicate significant aortic outflow obstruction in children?

Narrow pulse pressure

What pulse pressure change occurs on physical exam in severe aortic stenosis?

Systolic thrill at upper right sternal border, suprasternal notch, or carotids

Where is a thrill palpable on physical exam in significant aortic stenosis?

Systolic ejection click

What auscultatory finding is heard in valvular aortic stenosis?

Balloon valvuloplasty

What transcatheter procedure is used to relieve severe valvular aortic stenosis in critically ill infants?

Surgical commissurotomy or valve replacement

What surgical options are performed when balloon valvuloplasty fails in aortic stenosis?

Tetralogy of Fallot

What is the most common cyanotic congenital heart defect?

VSD, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy

What are the four anatomic components of Tetralogy of Fallot?

Position of the aorta directly over the VSD receiving blood from both ventricles

What defines an overriding aorta in Tetralogy of Fallot?

Boot-shaped heart

What pathognomonic cardiac silhouette is seen on chest X-ray in Tetralogy of Fallot?

Blackened lung fields with decreased pulmonary vascular markings

What pulmonary appearance is seen on chest X-ray in Tetralogy of Fallot?

Paroxysm of hyperpnea, irritability, deepening cyanosis, and decreased murmur intensity

What clinical features define an acute Tet spell?

Squatting

What physical posture do young children with Tetralogy of Fallot adopt to reduce right-to-left shunting?

Increases systemic vascular resistance to force more blood into pulmonary circulation

What is the physiologic mechanism of squatting during a Tet spell?

Knee-chest position

What initial physical maneuver should be performed when holding an infant experiencing a Tet spell?

Morphine sulfate

What medication suppresses the respiratory center and abolishes hyperpnea in a Tet spell?

Intravenous sodium bicarbonate

What medication is administered to treat metabolic acidosis during a severe Tet spell?

VSD patch closure, RVOT widening, and pulmonary valvotomy

What procedures are performed during complete surgical repair of Tetralogy of Fallot?

Modified Blalock-Taussig shunt

What palliative surgical shunt increases pulmonary blood flow prior to complete TOF repair?

Anatomic transposition where aorta arises from RV and pulmonary artery arises from LV

What is Transposition of the Great Arteries?

Anatomic malformation or physiological failure where forward output fails to meet metabolic demands while maintaining normal filling pressures

What is the clinical definition of heart failure?

Elevated natriuretic peptides OR objective evidence of cardiogenic congestion

What diagnostic criteria are required alongside structural or functional cardiac abnormalities to define heart failure?

Heart rate, preload, contractility, and afterload

What are the four main physiological factors that determine cardiac output?

Hypertensive heart disease, ischemic heart disease, severe lung disease, and valvular or rheumatic heart disease

What are the four primary underlying conditions responsible for the majority of heart failure cases?

Ischemic heart disease

What is the single most common cause of a newly reduced ejection fraction?

Dyspnea on exertion

What common exertion-related symptom in coronary artery disease can act as an anginal equivalent in heart failure?

Renin-angiotensin-aldosterone system activation

Which compensatory neurohormonal mechanism causes renal sodium and water retention, increasing preload and afterload?

Anti-diuretic hormone release

Which neurohormone induces free water reabsorption in the renal collecting ducts, increasing vascular filling pressures?

Endothelin

Which potent endogenous peptide causes systemic vasoconstriction and increases afterload in heart failure?

Diverts blood flow away from non-essential organs toward the heart and brain

How does the autonomic nervous system redistribute blood flow during low cardiac output states?

Cardiogenic shock, ischemic hepatopathy, and acute kidney injury

What severe end-organ perfusion complications result from persistent blood flow diversion?

Structural cardiac remodeling

What process involves myocyte hypertrophy, myocyte loss, fibroblast proliferation, and myocardial fibrosis?

Promote sodium and water excretion and induce systemic vasodilation

What is the primary physiological action of natriuretic peptides?

Reduces preload and afterload

How do natriuretic peptides affect ventricular loading conditions?

Inactive NT-proBNP and bioactive BNP

What two molecules are formed when the precursor peptide proBNP is cleaved?

20 minutes

What is the plasma half-life of bioactive BNP?

120 minutes

What is the plasma half-life of inactive NT-proBNP?

Ventricles

Where is BNP predominantly synthesized and released in a diseased heart?

High negative predictive value to rule out heart failure

What is the primary clinical utility of measuring serum BNP in a patient presenting with acute dyspnea?

BNP less than 100 pg/mL

What serum BNP cutoff level effectively rules out acute heart failure?