Case Report
A 68-year-old male was referred to our centre for a primary AF and atrial flutter (AFL) ablation. His past medical history included dyslipidaemia and a previous interstitial pneumonia SARS-CoV-2 related, complicated by bilateral pulmonary embolism and typical atrial flutter, treated by pharmacological cardioversion. Since hospital discharge the patient has suffered from frequent atrial fibrillation episodes, as documented by multiple smartwatch ECG registrations. Laboratory blood investigations showed the following: hemoglobin, 15,8 g/dL; white cell count, 7.8 x 109/L; sodium, 143 mmol/L; potassium, 4.0 mmol/L; urea, 27 mg/dL; and creatinine, 0,8 mg/dL. An echocardiogram documented normal biventricular size and function with normal left atrial dimensions and normal valvular function. As patient’s CHA(2)DS(2)-VASC was 1, according to our internal protocol, a transesophageal echocardiography was not performed. The procedure was made under uninterrupted anticoagulation with edoxaban. The patient provided written informed consent prior to the ablation procedure. The electrophysiological procedure was performed in deep sedation. After obtaining ultrasound-guided 2 left and 1 right femoral venous access5, a decapolar diagnostic catheter (Dynamic XTTM, Boston Scientific) was placed into coronary sinus (CS) and a steerable quadripolar diagnostic catheter (Dynamic TIPTM, Boston Scientific) was placed into the right ventricle. A 0.032 J-tip guidewire was placed from the right femoral access site to the superior vena cava (SVC). The AcQCross™️ Qx system combined with Medtronic FlexCathTM Advance steerable sheath was placed over the guidewire to the SVC. The AcQCross™️ Qx system was then connected to a pressure line by an Y connector (Fig.1A). After retracting the guidewire to the tip of the dilator, the sheath was pulled back caudally until an abrupt leftward movement (jump) of the tip below the aortic knob is observed (in the postero-anterior view) as the tip passes under the muscular atrial septum onto the fossa ovalis. After confirming the position of the tip in RAO and LAO view, the slider button was advanced forward on the AcQCross™️ Qx proximal handle, inducing the protrusion of the hollow stainless steel needle and resulting in effective puncture of the fossa ovalis (Fig.2A), as confirmed at first by the pressure line which showed LA pressure (Fig.1B). Thereafter the retained guidewire was easily advanced into LA and placed distally into the left superior pulmonary vein (Fig.2B) and finally the steerable sheath was advanced into the LA over the wire (Fig.2C-D). In this case the delivery of radiofrequency via the needle in order to puncture the septum was not necessary. The cryoballoon was then advanced without any need of sheat exchange and a conventional pulmonary vein isolation (PVI) with single application of cryoenergy for 240 sec per vein was performed. After PVI and during proximal CS pacing, an ablation index-guided cavotricuspid isthmus ablation with point by point lesions using 3D mapping (Carto 3, Biosense Webster) was performed. At the end of procedure an echocardiogram documented absence of pericardial effusion. The procedural data are displayed in Table 1. On the same evening of procedure an echocardiogram documented absence of pericardial effusion. On the next day after a clinical evaluation the patient was discharged. A follow-up with Holter ECG and medical evaluations at 3, 6 and 12 months from the ablation was scheduled.