Transjugular approach for EP-study and slow-pathway ablation in a patient with congenital atresia of inferior caval vein

Patient Presentation

A 55-year-old female was referred to our cardiology department because of sudden palpitations and presyncope. The patient had had recurrent episodes of palpitations in the last 4 years, which were characterized by a sudden onset and sudden termination. 

Initial work up

An ECG showed a narrow complex tachycardia with a heart rate of 200 bpm with p waves following the QRS complex. The tachycardia terminated spontaneously. A 12-lead ECG recorded during SR excluded manifest ventricular preexcitation.  Echocardiography showed no underlying structural heart disease.  

We suspected either an AVNRT or an AVRT via a concealed accessory pathway. As recommended in the current guidelines, we decided on catheter ablation as a first-line treatment. We started the EP study by puncturing the vena femoralis communis. It was not possible to advance the catheters to the right atrium, therefore we performed venography. We observed an anomalous location of the catheter on the left side of the vertebral column with contrast flowing toward the heart.  The catheter was thus advanced under radiographic guidance until it crossed the vertebral column below the diaphragm towards the azygos vein. The catheter turned in the arch of azygos and ended in the superior caval vein. 


 


Because of the unusual anatomy, the study was stopped. A contrast-enhanced CT revealed an atresia of the inferior vena cava, with the two iliac veins converging into an enlarged hemiazygos vein.
As the patient still had symptomatic arrhythmia on beta blockers, an alternative access strategy was necessary.

Diagnosis and Management

A superior venous approach was therefore utilized.  Ultrasound-guided venous access was obtained via the right internal jugular vein. Two separate introducer sheaths (8 Fr) were placed into the right internal jugular vein. A decapolar deflectable catheter was placed into the coronary sinus. The ablation catheter (Biosense Webster Navistar ® F-Curve, 4 mm) was positioned in the His region for conventional ep-testing, then moved into the right ventricle for the ventricular programmed stimulationNavistar ® F-Curve, 4 mm) was positioned in the His region for conventional ep-testing, then moved into the right ventricle for the ventricular programmed stimulation.


The atrial programmed stimulation revealed dual conduction properties of the AV conduction system, with a Wenckebach cycle length of 390 ms. 

The atrial extrastimulus testing revealed conduction mainly over the slow pathway (ERP/AVN/600 ms: 550 ms (FP); 370 ms SP), without a Jump beat. Under programmed stimulation an AVNRT of the slow-fast type with a cycle length of 400 ms and a VA time of 40 ms was repeatedly induced.


The ventricular programmed stimulation showed decremental properties of the AV conduction system, thus an accessory pathway was unlikely. Electroanatomical mapping of the right atrium was performed using the CARTO® 3 System. The His region was identified and marked. The tip of the ablation catheter was repositioned to the posterior right atrial septum near the upper aspect of the coronary sinus ostium. We proceeded with the RF ablation at the basis of the triangle of Koch in the slow-pathway region with a total of 8 RF applications (3:27 min, 55°, 55W).
 
During application of RF energy, a junctional rhythm was registered. Afterwards, PES revealed conduction only over the fast pathway. No AVNRT could be induced. The venous access was closed with manual compression. 

Conclusions

Our case shows that RF ablation of the slow pathway using a right jugular vein access can be performed successfully and safely.