We have recently observed mobile strands the inferior vena cava (IVC) complicating radiofrequency ablation (RFA), using echocardiography.
Retrospective review of consecutive patients with IVC strands (Gr I) over a 30-month period. Control group (Gr II) was age-matched RFA patients without IVC strands.
IVC strands were detected post RFA in 55/757 (7%) patients (Gr I)- by TTE in 47 and TEE in 8. None had IVC strand prior to RFA. Arrhythmia was AVNRT in 18 (33%), AVRT in 17(31)%), atrial tachycardia in 8 (15%), atrial flutter in 4 (7%), atrial fib in 3 (5%) and VT in 4 (7%). RFA site was RA in 38(69%), LA in 9 (16%), RV in 2 (4%), LV in 1 (2%) and none in 5 (9%). Mean width of strand was 3.4+/− 1.6 mm. In 5/55 pts IVC strands extended into RA (9%). In the remaining 50 pts, strand terminated 53 +/−28 mm below IVC-RA junction. Maximal length was 51 +/− 31 mm. IVC size was normal (15+/−4.3 mm) and spontaneous echo contrast seen in IVC post RFA in 10 (18%) in Gr I. No difference between Gr I and Gr II was seen in no. of short sheaths (4.2+/−0.6 vs. 4.3+/−0.7), long sheaths (1.1+/− 0.3 vs. 1.4+/−0.5) or duration of procedure (506+/−169 min vs. 483+/−143). Heparin was used during procedure in 11/55 pts in Gr I (20%) and 13/40 pts in Gr II (32.5%). Post ablation treatment in Gr I pts consisted of ASA only in 21(38%), clopidogrel in 2 (4%), LMWH with warfarin in 27 (49%), warfarin only in 3 (5%), regular heparin and warfarin in 1 (2%) and LMWH only in 1 (2%). Symptoms suggestive of pulmonary embolism (PE) occurred in 2 patients (4%) with negative workup. Long-term follow-up in 31 pts identified no evidence of PE.
Mobile IVC thrombotic strands are seen after RFA in 7% of patients. These strands reach RA only rarely and appear to have a benign clinical course.
C.A. Sivaram, None.