Cardiology Flashcards
What is the underlying pathology of PDA?
PDA - connection between the Aorta and the Pulmonary artery
Once pulmonary resistance falls, blood flows L to R into the pulmonary artery which can result in over-circulation into the lungs, wide pulse pressure and pulmonary vascular disease (like a VSD)
What causes normal physiological splitting of the S2?
Delayed closure of the PV with respect to AV (usually as a result of deep inspiration)
How do the heart sounds change in the setting of PPHN?
Fixed single S2 (increased PVR will prevent any obvious splitting of S2)
What dose of prostaglandin should be used in treatment of suspected congenital heart disease?
0.01 - 0.02 µg/kg/min
What are the short and long term side effects of prostaglandin?
Short term: • Apnea • Skin flushing • Fever • Seizure-like activity • Hypotension • Bradycardia
Long term: • Periosteal hyperostosis • Gastric outlet obstruction • Necrotizing enterocolitis • Diarrhea
Where do the majority of coarctations take place?
Just below (after) the origin of the L subclavian artery (98%)
How does prostaglandin help palliate the changes caused by coarctation of the aorta?
Prostaglandins help maintain the patency of the PDA, which in turn, may serve to widen the juxtaductal area of the aorta and provide temporary relief from the obstruction
As such, perfusion to the lower half of the body becomes dependent on the PDA and consequently, the RV output
What is the mechanism for radial-femoral delay?
Given the presence of coarctation, blood flow to the lower half of the body is reliant on collateral vessels. Otherwise, normally the femoral pulse should be felt before the radial pulses
What difference is acceptable with respect to BP measured in the upper and lower extremities?
Legs should be 10-20 mmHg higher than that of the upper extremities
What bony changes can be caused by a severe coarctation?
Notching of the inferior border of the ribs
pressure erosion by enlarged collateral vessels; common by late childhood
Once a coarctation is discovered, when should repair take place?
Once the patient has been stabilized; age and growth are not reasons for delaying surgical repair of coarctation
A child has just had their coarctation repaired when they develop rebound hypertension and abdominal pain. What is the mechanism?
Postcoarctectomy Syndrome
Postoperative mesenteric arteritis may be associated with acute hypertension and abdominal pain in the immediate postoperative period
What is the treatment of choice in a young child who has had re-coarctation despite a successful coarctectomy?
Balloon angioplasty
What congenital heart defect can lead to ST changes in the anterolateral leads (avL, V5, V6)?
ALCAPA
• Anomalous left coronary arteries from pulmonary artery
• Presents in teens/young adulthood unless there are no collaterals
What congenital heart defects are seen/associated with R aortic arch?
- Tetrology of Fallot
- Truncus arteriosus
Otherwise, patients tend to be asymptomatic
What conditions are associated with vascular ring?
Anomalous L sided vessels (PA, innominate and carotid arteries), double aortic arch, or R aortic arch with L ligamentum arteriosum
What cardiac lesions are linked to the following genetic conditions?
Down Syndrome DiGeorge Syndrome Williams Syndrome Turner Syndrome Marfan Syndrome
Down syndrome – AVSD DiGeorge – TOF Williams – supravalvular aortic stenosis Turner – coarct, bicuspid AoV Marfan - dilated aortic root, MVP
What are some indications for treatment of PVCs?
- 2+ PVCs in a row
- Multiform PVCs
- Increased PVCs with activity (should decrease)
- R-on-T phenomenon (PVC depolarization on T-wave of preceding beat)
- Extreme frequency (>20% total beats on Holter)
What is the most common cause of SVT in infants?
Atrioventricular reciprocating tachycardia (AVRT) as the result of an accessory pathway
What are the 4 major categories of SVT?
- Reentrant tachycardias using an accessory pathway
- AVRT - Most common mechanism of SVT in infants - Reentrant tachycardias without an accessory pathway
- Atrioventricular node reentry tachycardia (AVNRT); increasing incidence in childhood and into adolescence, associated with exercise, 2 pathways (fast and slow) - Ectopic or automatic tachycardias
- Common in patients following cardiac surgery or with cardiomyopathy - Chaotic/multifocal atrial tachycardia
What is the most ominous sign in a patient with SVT?
Syncope with WPW Syndrome; these patients need catheter ablation
What treatment options are available for children with acute runs of SVT?
• Abortion maneuvers (vagal stimulation with ice, Valsalva maneuver, straining, breath holding, or standing on their head)
○ Ocular pressure must never be performed, and carotid sinus massage is very rarely effective
• Pharmacologic alternatives
○ Adenosine by rapid IV push (tx of choice); Never give without a means for DC cardioversion
○ CCB (i.e. verapamil) in older children (contraindicated if <1 year)
○ Procanimide
○ Amiodarone
• Synchronized DC cardioversion (0.5-2 J/kg) is recommended as the initial management in unstable patients
What medication should be used in the case of children with WPW?
→ β-blockers
digoxin or CCB may increase the rate of antegrade conduction of impulses through the bypass tract, with the possibility of ventricular fibrillation, and are therefore contraindicated