1. Trifascicular Block
Candice Reyes
Cardiology
July 17, 2009

2. Subjective
• 57 y/o male transferred to RLAH for eval
and treatment of R 3rd met plantar ulcer
and gangrene of R 3rd toe
• Pt has no h/o cardiac dz, he has no
cardiac sx
• PMHx: DM x2yrs w/o tx

3. Objective
• Vitals: BP 128/75 P 86 T99 O2Sat 99% Wt
95.6 F.S. 286
• CV: decr heart tones w/RRR S1S2 w/o
murmur
• Resp: LCTA B/L
• Extremities: RLE has erythema and 2+
pitting edema

5. EKG Discussion
• Prolongation of PR interval – 1st Degree
AV Block
• RBBB
• LAFB
• Findings suggest trifascicular block

6. Trifascicular Block
• Conduction blocks in all 3 fascicles
– Can be permanent or transient
• Criteria:
– 1) RBB and LASF w/1st degree AV block
– 2) RBB and LPIF w/1st degree AV block
– 3) LBB w/1st degree AV block or
– 4) Alternating RBBB and LBBB

7. Trifascicular Block
• Trifascicular, along w/bifascicular, blocks
indicate advanced heart dz
• BUT long-term follow-up studies of
ambulatory patients indicate that risk of
sudden progression to complete heart
block and sudden death d/t ventricular
asystole is not great
Bolton Edmund, "Chapter 28. Disturbances of Cardiac Rhythm and Conduction" (Chapter). Tintinalli
JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM: Tintinalli's Emergency Medicine: A
Comprehensive Study Guide, 6e: http://www.accessmedicine.com/content.aspx?aID=587596.

8. Assessment and Plan
• Dr. Quesada’s Assessment and Plan: These
findings suggest a trifascicular block.
Progression of chronic bifasicular or trifascicular
block to complete heart block is infrequent. This
pt is asx and was very active prior to
hospitalization
• Per guidelines, the pt has intermediate to high
clinical predictors (DM asx trifascicular block)
and is scheduled for a low risk surgical
procedure