Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience

Abstract

Background: The ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks.

Methods: We describe our first multicenter experience of 255 consecutive patients (235 females, 25.94 ± 3.84 years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n = 204, 80%) or POTS (n = 51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected.

Results: Normal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months, all patients presented stable SR. At a mean of 4.07 ± 1.8 years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest > 5 s.

Conclusions: Preliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

Keywords: Arrhythmias ablation; Hybrid ablation; Hybrid therapy; Inappropriate sinus tachycardia; Postural orthostatic tachycardia; Sinus node.

Fig. 1

Camera view from the right thoracoscopic approach. SVC, superior vena cava; RA, right atrium. Panel A is showing the close pericardium view; the schema explains the relation between all different structures; panel B is showing the relation modification between the different structures after opening the pericardium

Fig. 2

Camera view from the right thoracoscopic approach. SN, sinus node; RA, right atrium; RSPV, right superior pulmonary vein; IVC, inferior vena cava; SVC, superior vena cava. Panel A showing the clamping of crista terminalis in relation with SN and RSPV; panel B showing the clamping of IVC in relation with RA; panel C showing the clamping of SVC in relation with RA and SN; panel D showing the second clamping of SVC in relation with RA and SN; the yellow line underlines the previous ablation line

Fig. 3

Schema of the right atrium (RA) in red the conduction system targeting during ablation, in blue the conduction system preserved during ablation, with a white line the schematic orientation of ablation line. SA node, sinoatrial node; AV node, atrioventricular node

Fig. 4

Example of post-ablation electroanatomical mapping. We can appreciate the isolation of the superior and inferior cava veins and the lateral line

Fig. 5

Example of electrocardiogram pre (A the patient was under general anesthesia) and post (B post procedure without anesthesia) procedure

Fig. 6

Hybrid simultaneous setting. EP, electrophysiologist; CS, cardiac surgeons

Fig. 7

Example of pre (panel A) and post (panel B) mapping