Anatomic Variants

Question 1

Right Atrium

Answer 1

• Eustachian valve — direct IVC blood flow across fossa ovalis in fetus
• Crista terminalis — at junction of SVC and RA ; tachyarrythmias
• Chiari network — thin filamentous net like that exists in RA ; can result in thrombi ; associated with PFO, aneurysmal IAS, thromboembolic events ; atrial arrhythmias
• Thebesian valve — valve of the CS
• Persistent left superior vena cava — dilated CS ; implications for cardioplegia
• PFO
• Atrial septal aneurysm — excursion > 1.5 cm ; associated PFO 50-89% ; cerebral emboli
• Lipomatous hypertrophy of IAS — benign infiltration of fat giving dumbbell appearance ; associated atrial arrhythmias
• Pectinate muscles
• RAA

Question 2

Right Ventricle

Answer 2

• Trabeculations

* Moderator band — base of anterior papillary muscle to septum ; carries part of RBB

Question 3

Left Atrium

Answer 3

• LAA variants
• Coumadin ridge
• Cor triatriatum sinister
• pulmonary veins

Question 4

Left Ventricle

Answer 4

• LV band = false tendon

* Papillary muscles

Question 5

Miscellaneous

Answer 5

• Transverse sinus
• Lambl’s excrescences
• Catheters and cannulas
• masses, tumors, etc.