Quiz #39: Where is the catheter?

Two sets of images are given (PA and Lateral views in each set, from the same angiogram before and during contrast injection) obtained during pre-Glenn catheterization in this patient with Tricuspid Atresia.

Questions & Answers:

1) Trace the catheter course.

Answer: IVC-RA-ASD-LA-MV-LV-VSD-RV

2) Where do you think is the tip of the catheter?

Answer: RV

3) Using the second set of images, comment on great arteries relationship? (Normal relationship or not?).

Answer: Normally-related great arteries.

4) Bonus question: Based on the above observations, what classification type of tricuspid atresia is this?

Answer: Type 1b (Tricuspid Atresia with normally-related great arteries, Small VSD and PS). See the last image for classification of Tricuspid atresia.

(Click on the image to enlarge)

(Click on the image to enlarge)

(From Moss & Adams 5^th ed. 1995. Chapter 61: Tricuspid Atresia by Dr. Rosenthal A, Dick, McD II. p 903.)

Quiz #38: EKG Answer

Question: 5-month old with Down Syndrome. 2nd Postoperative day after surgical closure of large inlet VSD. What is the diagnosis?

Answer: Wenckebach phenomenon (2nd Degree, Mobitz type 1 AV block).

Discussion:

1) There are ventricular ectopies (escape beats) after the non-conducted P waves (Large, dark arrows). These beats have confused some responders.

2) "Grouping of beats" as seen here is a feature of Wenckebach phenomenon and is helpful in gestalt recognition.

3) Remember: Shortest PR interval should be seen in the beat that immediately follows the non-conducted beat. This will help to differentiate other rhythms (e.g. 3rd degree AV block with coincidental appearance to Wenckebach, for a short time). If you look at a longer strip of EKG, 3rd AV block with betray itself.

(Click on the image to enlarge)