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Abstract Background Insertion of electrode catheters into the coronary sinus (CS) through the right internal jugular vein (RIJV) carries risks of pneumothorax and severe hematoma formation. This study was performed to compare the safety and feasibility of catheterization through the left cubital superficial vein versus the RIJV. Methods This prospective nonrandomized study involved consecutive patients who underwent catheter ablation from September 2021 to February 2023. Blind puncture techniques were used in the left cubital vein group; ultrasound‐guided insertion was performed in the RIJV group. The success rates of sheath insertion and CS catheterization, the procedure and fluoroscopy times of CS cannulation, and complications were compared between groups. Results The left cubital vein group comprised 152 patients, and the RIJV group comprised 58 patients. The sheath insertion success rate was significantly lower in the cubital vein group than in the RIJV group (84.9% vs 100%, respectively; p = .0008). In the cubital vein group, blind puncture attempts failed in 20 patients; three patients developed guidewire‐induced venous injury. One arterial puncture occurred in the RIJV group. After successful sheath insertion, no significant differences were observed in the CS cannulation success rate (97% vs 100%, p = .55), procedure time (median [range], 93 [51–174] vs 74 [44–129] s; p = .19), or fluoroscopy time (median [range], 66 [36–134] vs 48 [30–92] s; p = .17). No serious complications requiring procedural discontinuation occurred. Conclusion The left cubital vein approach is practical, offering a viable alternative to the RIJV approach.

Abstract Background We explore an optimized approach for increasing lesion size using a novel ablation catheter with a surface thermocouple and efficient irrigation in a temperature‐control setting. Methods We conducted radiofrequency applications at various power levels (35 W, 40 W, and 45 W), contact forces (CFs, 10 g/20 g), and durations (60 s/120 s/180 s) in perpendicular/parallel catheter orientations, with normal saline irrigation (NS‐irrigation) and Half NS‐irrigation (HNS‐irrigation) in an ex‐vivo model (Step 1). In addition, we performed applications (35 W/40 W/45 W for 60 s/120 s/180 s in NS‐irrigation and 35 W/40 W for 60 s/120 s/180 s in HNS‐irrigation) in four swine (Step 2), evaluating lesion characteristics and the occurrence of steam pops. Results In Step 1, out of 288 lesions, we observed 47 (16.3%) steam pops, with 13 in NS‐irrigation and 34 in HNS‐irrigation (p = .001). Although steam pops were mostly observed with the most aggressive setting (45 W/180 s, 54%) with NS‐irrigation, they happened in less aggressive settings with HNS irrigation. Lesion size significantly increased with longer‐duration ablation but not with HNS‐irrigation. The optimal %impedance‐drop cutoff to predict steam pops was 20% with a negative‐predictive‐value (NPV) = 95.1% including NS‐ and HNS‐irrigation groups, and 22% with an NPV = 96.1% in NS‐irrigation group. In Step 2, similar to the ex‐vivo model, lesion size significantly increased with longer‐duration ablation but not with HNS‐irrigation. Steam pops were absent with NS‐irrigation (0/35) even with the largest %impedance‐drop reaching 31% at 45 W/180 s. All steam pops were observed with HNS‐irrigation (6/21, 29%). The optimal %impedance‐drop cutoff predicting steam pops was 24% with an NPV = 96.3% including both NS‐ and HNS‐irrigation groups. Conclusions Rather than using HNS‐irrigation, very long‐duration of radiofrequency applications up to 45 W/180 s may be recommended to safely and effectively increase lesion dimensions using this catheter with NS‐irrigation.

Abstract Background This study aimed to establish a systematic method for diagnosing atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed nodoventricular pathway (cNVP). Methods We analyzed 13 cases of AVNRT with a bystander cNVP, 11 connected to the slow pathway (cNVP‐SP) and two to the fast pathway (cNVP‐FP), along with two cases of cNVP‐related orthodromic reciprocating tachycardia (ORT). Results The diagnostic process was summarized in three steps. Step 1 was identification of the presence of an accessory pathway by resetting the tachycardia with delay (n = 9) and termination without atrial capture (n = 4) immediately after delivery of a His‐refractory premature ventricular contraction (PVC). Step 2 was exclusion of ORT by atrio‐His block during the tachycardia (n = 4), disappearance of the reset phenomenon after the early PVC (n = 7), or dissociation of His from the tachycardia during ventricular overdrive pacing (n = 1). Moreover, tachycardia reset/termination without the atrial capture (n = 2/2) 1 cycle after the His‐refractory PVC was specifically diagnostic. Exceptionally, the disappearance of the reset phenomenon was also observed in the two cNVP‐ORTs. Step 3 was verification of the AVN as the cNVP insertion site, evidenced by an atrial reset/block preceding the His reset/block in fast–slow AVNRT with a cNVP‐SP and slow–fast AVNRT with a cNVP‐FP or His reset preceding the atrial reset in slow–fast AVNRT with a cNVP‐SP. Conclusion AVNRT with a bystander cNVP can be diagnosed in the three steps with few exceptions. Notably, tachycardia reset/termination without atrial capture one cycle after delivery of a His‐refractory PVC is specifically diagnostic.

Abstract A 74‐year‐old man was admitted for a second replacement of a transvenous implantable cardioverter‐defibrillator (ICD) generator at 15 years after implantation. Postoperatively, electrocardiographic monitoring showed atrial lead malfunction. Chest X‐ray revealed that the tip of the active fixation atrial lead was dislocated. We present a case of atrial lead dislodgement after a very long‐term period of an ICD implantation.