Atrioventricular nodal tachycardia in a patient with anomalous inferior vena cava with azygos continuation and persistent left superior vena cava

Electrophysiological features and radiofrequency catheter ablation of supraventricular tachycardia in patients with persistent left superior vena cava

BACKGROUND

The electrophysiological features and roles of persistent left superior vena cava (PLSVC) in supraventricular tachycardia (SVT) are not known.

OBJECTIVE

The purpose of this study was to elucidate the electrophysiological features and roles of PLSVC in patients with SVT.

METHODS

We included 37 patients with PLSVC (mean age 43.5 ± 17.1 years; 35.1% men) and 510 patients without PLSVC (mean age 43.9 ± 18.8 years; 48.2% men) who underwent an electrophysiology study for SVT. The number of induced tachycardias, location of the slow pathway (SP) or accessory pathway (AP), and radiofrequency catheter ablation (RFCA) outcomes were compared between patients with and without PLSVC. During RFCA of the left AP, a coronary sinus (CS) catheter was placed into the left superior vena cava (left superior vena cava group) or the great cardiac vein (great cardiac vein group). The RFCA outcomes were compared between the groups.

RESULTS

In patients with PLSVC, 40 tachycardias were induced: atrioventricular nodal reentrant tachycardia (AVNRT) (n = 19), atrioventricular reentrant tachycardia (n = 17), and focal atrial tachycardia (n = 4). Among patients with AVNRT, an SP in the CS was significantly more frequent in patients with PLSVC than in those without PLSVC (47.4% vs 3.8%; P < .001). In patients with the left AP, the number of RFCA attempts and recurrence were lower in the great cardiac vein group than in the left superior vena cava group.

CONCLUSION

An SP in the CS is prevalent in patients with AVNRT and PLSVC. It is useful to place a CS catheter into the great cardiac vein in patients with a left AP and PLSVC.

Atrioventricular nodal reentrant tachycardia ablation and inferior vena cava agenesis

Congenital anomalies of the inferior vena cava (IVC) are rare and very often diagnosed in asymptomatic patients during computed tomography performed for other purposes. These anomalies can have significant clinical implications, for example if electrophysiology procedures are needed. Diagnostic and ablation procedures are difficult since catheter manipulation and positioning are more complex. We present here a case of successful atrioventricular nodal reentrant tachycardia ablation in a patient with unexpected IVC agenesis, using an azygos route.