Which of these is a cyanotic heart defect?

Daman & Diu Staff Nurse - 2018

Child Health Nursing (Pediatrics)

Easy

Appeared in: Daman & Diu Staff Nurse - 2018

Explanation

Tetralogy of Fallot (TOF) is a cyanotic congenital heart defect.
It is characterized by a right-to-left shunt, where deoxygenated blood from the right ventricle is shunted to the left ventricle and aorta, bypassing the lungs.
The primary cause of the right-to-left shunt is the obstruction of the right ventricular outflow tract (pulmonary stenosis), which increases the pressure in the right ventricle above that of the left ventricle.
This mixing of deoxygenated blood with oxygenated blood in the systemic circulation leads to cyanosis, a bluish discoloration of the skin and mucous membranes.

Option A: Ventricular septal defect (VSD) is typically an acyanotic heart defect. The defect in the ventricular septum allows blood to flow from the high-pressure left ventricle to the low-pressure right ventricle (a left-to-right shunt), so oxygenated blood recirculates to the lungs without causing systemic cyanosis.
Option B: Patent Ductus Arteriosus (PDA) is an acyanotic heart defect. The persistent opening between the aorta and the pulmonary artery allows oxygenated blood from the high-pressure aorta to flow back into the pulmonary artery (a left-to-right shunt).
Option D: Atrial septal defect (ASD) is an acyanotic heart defect. The hole in the atrial septum causes a left-to-right shunt, where oxygenated blood from the left atrium flows to the right atrium and back to the lungs.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of congenital heart defects (cyanotic vs. acyanotic) as background academic context rather than a clinical decision trigger.
Nurses must be able to differentiate between cyanotic and acyanotic heart defects to anticipate clinical presentations and potential complications.
A key nursing intervention for an infant experiencing a hypercyanotic 'Tet spell' is to immediately place them in the knee-chest position. This increases systemic vascular resistance, which helps to decrease the right-to-left shunt and increase blood flow to the lungs.
Pulse oximetry screening for critical congenital heart disease (CCHD) is a standard of care for all newborns before hospital discharge to detect conditions like TOF early.

How to Approach the Question

First, identify the core concept being tested, which is the classification of congenital heart defects.
The keyword is 'cyanotic'. Recall the definition of a cyanotic defect: a condition that allows deoxygenated blood to enter the systemic circulation, typically through a right-to-left shunt.
Mentally categorize the given options into acyanotic (left-to-right shunt) and cyanotic (right-to-left shunt) groups.
Recall that VSD, PDA, and ASD are the classic examples of acyanotic defects.
Identify Tetralogy of Fallot as the classic example of a cyanotic defect, characterized by its four anatomical abnormalities.
Select the option that matches the 'cyanotic' classification.

Concept Tested & Keywords

Concept Tested: Classification of congenital heart defects (cyanotic vs. acyanotic)
Stem keywords: cyanotic heart defect
Lead-in keywords: Which
Negative lead-in flag: false

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E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 2 (215-514) p. 1

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 541-543