During a regular checkup of an 8-year-old child, you note a loud first heart sound with a fixed and widely split second heart sound at the upper left sternal border that does not change with respirations. The patient is otherwise active and healthy. Which of the following heart lesions most likely explains these findings?
A) Atrial septal defect
B) Ventricular septal defect
C) Isolated tricuspid regurgitation
D) Tetralogy of Fallot
E) Mitral valve prolapsed
a atrial septal defect
Second heart sound is widely split because the pulmonary hangout interval* is wide
Fixed because , the RV stroke volume does not show the normal respiratory changes.
This is due to dynamic phasic shunting across the IAS ( For example : During inspiration , if RA,RV volume gets augmented by 50ml from IVC inflow , in expiration this IVC augumentation is removed but a 50 ml augmentation from left atrium takes place , this keeps the RV diastolic , as well as systolic volume relatively constant.) This makes the 2nd heart sound fixed .
if RA,RV volume gets augmented by 50ml from IVC inflow , in expiration this IVC augumentation is removed but a 50 ml augmentation from left atrium takes place , this keeps the RV diastolic ,.
During a regular checkup of an 8-year-old child, you note a loud first heart sound with a fixed and widely split second heart sound at the upper left sternal border that does not change with respirations. The patient is otherwise active and healthy. Which of the following heart lesions most likely explains these findings?
A) Atrial septal defect
B) Ventricular septal defect
C) Isolated tricuspid regurgitation
D) Tetralogy of Fallot
E) Mitral valve prolapsed
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
USMLE Forums
402.5K posts
115K members
Since 2009
A forum community dedicated to the United States Medical Licensing Examination. Come join the discussion about schools, exams, news, prep, reviews, accessories, classifieds, and more!