Robotic-Assisted Left Ventricular Lead Placement.

Robot-assisted left ventricular lead implantation for cardiac resynchronization therapy is a feasible and safe technique with superior visualization, dexterity, and precision to target the optimal pacing site. The technique has been associated with clinical response and beneficial reverse remodeling comparable with the conventional approach via the coronary sinus. The lack of clinical superiority and a residual high nonresponder rate suggest that the appropriate clinical role for the technique remains as rescue therapy.

Dual AV Nodal Nonreentrant Tachycardia Resulting in Inappropriate ICD Therapy in a Patient with Cardiac Sarcoidosis.

Dual atrioventricular nodal nonreentrant tachycardia (DAVNNT) occurs due to concurrent antegrade conduction over fast and slow atrioventricular nodal pathways and is treated by slow pathway modification. We describe a unique case of a patient with cardiac sarcoidosis who received inappropriate ICD shocks for DAVNNT. Atrial and ventricular device electrograms satisfied both rate and V>A criteria for ventricular tachycardia. We postulate that alterations in refractoriness and conduction as is seen in cardiac sarcoidosis (CS) may have contributed to occurrence of DAVNNT.

Nonreentrant supraventricular tachycardia misdiagnosed as inappropriate sinus tachycardia.

We report a case of a woman with incessant palpitations initially misdiagnosed as inappropriate sinus tachycardia that proved refractory to ß-blockers. At the time of electrophysiologic testing, a sustained narrow-complex tachycardia with a 1:2 atrioventricular relationship was repeatedly initiated by a posterior fascicle depolarization induced by means of a timed ventricular extrastimulus. The tachycardia was repeatedly terminated with a timed atrial extrastimulus, which excluded junctional bigeminy and confirmed the diagnosis of nonreentrant supraventricular tachycardia. Catheter ablation of the slow pathway eliminated dual-pathway conduction and tachycardia.

Detection of atrial fibrillation using an implantable loop recorder following cryptogenic stroke: implications for post-stroke electrocardiographic monitoring.

PURPOSE: Approximately 10-40% of strokes are cryptogenic (CS). Long-term electrocardiographic (ECG) monitoring has been recommended in these patients to search for atrial fibrillation (AF). An unresolved issue is whether ambulatory ECG (AECG) monitoring should be performed first, followed by an implantable loop recorder (ILR) if AECG monitoring is non-diagnostic, or whether long-term ECG monitoring should be initiated using ILRs from the onset. The purpose of this study was to assess, using an ILR, AF incidence in the first month after CS. METHODS: We enrolled consecutive CS patients referred for an ILR. All patients were monitored via in-hospital continuous telemetry from admission until the ILR (Medtronic [Minneapolis, MN] LINQ™) was implanted. The duration and overall burden of all AF episodes ≥ 2 min was determined. RESULTS: The cohort included 343 patients (68 ± 11 years, CHA2DS2-VASc 3.5 ± 1.7). The time between stroke and ILR was 3.7 ± 1.5 days. During the first 30 days, only 18 (5%) patients had AF. All episodes were paroxysmal, lasting from 2 min to 67 h and 24 min. The median AF burden was 0.85% (IQR 0.52, 10.75). During 1 year of follow-up, 67 (21%) patients had AF. CONCLUSION: The likelihood of AF detection by an ILR in the first month post-CS is low. Thus, the diagnostic yield of 30 days of AECG monitoring is likely to be limited. These data suggest a rationale for proceeding directly to ILR implantation prior to hospital discharge in CS patients, as many have AF detected during longer follow-up.

Outcomes of His-bundle pacing upgrade after long-term right ventricular pacing and/or pacing-induced cardiomyopathy: Insights into disease progression.

BACKGROUND: His-bundle pacing (HBP) is a physiological alternative to right ventricular pacing (RVP). The outcomes of HBP in patients with longstanding atrioventricular block (AVB) and RVP are unknown OBJECTIVE: The purpose of this study was to retrospectively assess the feasibility of HBP in patients with chronic RVP and longstanding AVB and to evaluate its efficacy in reversing the adverse remodeling induced by RVP. METHODS: HBP was attempted in patients with longstanding AVB and chronic RVP and/or pacing-induced cardiomyopathy (PICM) in need for resynchronization therapy. The site of conduction block and feasibility of HBP was documented. Electrocardiographic and echocardiographic assessments at baseline and follow-up were recorded. RESULTS: HBP was successful in 79 of 85 patients (93%) with RVP for 77.6 ± 74.8 months (range 2-540 months). AV nodal block was present in 59 and infranodal block in 26. QRS duration increased from 123 ± 31 ms at baseline to 177 ± 17 ms (P <.001) during RVP and decreased to 115 ± 20 ms with HBP (P <.001). T-wave memory was observed in 53 of 79 patients with HBP and normalized in 2-12 weeks. HBP threshold was 1.47 ± 0.9 V @ 1 ms at implant and 1.9 ± 1.3 V @ 1 ms at last follow-up (25 ± 24 months). In 60 patients with PICM in whom left ventricular ejection fraction decreased from 54% ± 7.7% at baseline to 34.3% ± 9.6% (P <.001), ejection fraction improved to 48.2% ± 9.8% (P <.001) after HBP CONCLUSION: Despite a long duration of AVB and chronic RVP, HBP normalized QRS complexes and T waves with stable thresholds, suggesting that progression of distal conduction disease is uncommon in this population. Electrical and structural changes induced by chronic RVP were consistently reversed with HBP.

The Efficacy of His Bundle Pacing: Lessons Learned From Implementation for the First Time at an Experienced Electrophysiology Center.

OBJECTIVES: This study sought to evaluate the clinical and procedural characteristics impacting outcomes during implementation of a His bundle pacing (HBP) program in a real-world setting. BACKGROUND: Right ventricular pacing is associated with an elevated risk of heart failure, but device reprogramming and upgrades have significant challenges. HBP has emerged as an alternative and is reported to be highly successful in the hands of highly experienced centers. METHODS: All patients referred for permanent pacemaker implantation at the Valley Hospital (Ridgewood, New Jersey) between October 2015 and October 2017 were evaluated; a subset of 24% was selected for HBP. RESULTS: Permanent HBP was feasible with an acute implant success rate of 75%. HBP in the presence of bundle branch block (64% vs. 85%; p = 0.05) or complete heart block (56% vs. 83%; p = 0.03) was significantly less successful. The pattern of atrioventricular block in combination with bundle branch block (BBB) further affects outcomes. HBP is highly successful across the spectrum of atrioventricular block pattern severity in the absence of BBB. In the presence of BBB, Mobitz II AV block and complete heart block significantly attenuated HBP success compared with Mobitz I atrioventricular block (62% vs. 100%; p = 0.02). A rising threshold was observed in 30%, and 8% required lead intervention. CONCLUSIONS: HBP was feasible and readily learned with a high implant success in the hands of experienced electrophysiologists without prior exposure to the technique. BBB and atrioventricular block pattern appears to affect success. The technique is limited by a high rate of rising thresholds and lead intervention. These data have important implications for patient selection.

Robotic-Assisted Left Ventricular Lead Placement.

Robot-assisted left ventricular lead implantation for cardiac resynchronization therapy is a feasible and safe technique with superior visualization, dexterity, and precision to target the optimal pacing site. The technique has been associated with clinical response and beneficial reverse remodeling comparable with the conventional approach via the coronary sinus. The lack of clinical superiority and a residual high nonresponder rate suggest that the appropriate clinical role for the technique remains as rescue therapy.