Cardiac resynchronization therapy (CRT) typically is attempted with biventricular pacing (BiVP). One-third of patients are nonresponders. His-bundle pacing (HBP) has been evaluated as an alternative ...means of effecting CRT because it generates truly physiologic ventricular activation, as evidenced in part by the morphologic identity between normally conducted and paced QRS complexes.
The purpose of this study was to assess the feasibility of, and clinical response to, permanent HBP as an alternative to BiVP in CRT-indicated patients.
Patients were implanted with a right atrial pacing lead, defibrillation lead, left ventricular (LV) lead via the coronary sinus, and HBP lead. His and LV leads were plugged into the LV port via a Y-adapter. After successful implant, patients were randomized in single patient-blinded fashion to either HBP or BiVP. After 6 months, patients were crossed over to the other pacing modality and followed for another 6 months. Quality-of-life assessments, echocardiographic measurements, New York Heart Association classification, and 6-minute hall walk test were obtained at baseline and at each 6-month follow-up.
Twenty-nine patients were enrolled; 21 (72%) demonstrated electrical resynchronization (QRS narrowing) at implant. Twelve patients completed the crossover analysis at 1 year. Clinical outcomes (quality of life, New York Heart Association functional class, 6-minute hall walk test, LV ejection fraction) were significantly improved for both pacing modes compared with baseline measures.
In this crossover comparison between HBP and BiVP, HBP was found to effect an equivalent CRT response. QRS narrowing was observed in 21 of 29 patients, suggesting this approach may be feasible in more patients with left bundle branch block than previously assumed.
Magnetic resonance imaging (MRI) has been safely performed in some patients with cardiac implantable electronic devices (CIEDs) under careful monitoring and prespecified conditions. ...Pacemaker-dependent patients are often excluded, partly because of the potential for "power-on reset" (PoR), which can lead to a change from asynchronous to inhibited pacing with consequent inhibition of pacing due to electromagnetic interference during MRI.
The purpose of this study was to review risk factors for PoR during MRI.
A prospective study was performed between January 2008 and May 2013 in patients with CIEDs undergoing clinically indicated MRI. Eligible patients were not pacemaker dependent. Devices were interrogated before and after MRI, programmed to an asynchronous mode or an inhibition mode with tachyarrhythmia therapies turned off, and reprogrammed to their original settings after MRI.
MRI scans (n = 256) were performed in 198 patients with non-MRI-conditional CIEDs between 2008 and 2013 (median age 66 years; interquartile range 57-77 years; 59% men). PoR occurred during 9 MRI scans (3.5%) in 8 patients. PoR was more frequent with Medtronic devices than with other generator brands (n = 9/139 vs 0/117 6% vs 0%; P = .005). Devices with PoR were all released before 2002 and were implanted from 1999 to 2004. Effects of PoR included a decrease in heart rate during MRI (n = 4) and transient anomalous battery life indication (n = 1). All devices functioned normally after MRI.
PoR occurs infrequently but can cause deleterious changes in pacing mode and heart rate. MRI should not be performed in pacemaker-dependent patients with older at-risk generators. Continuous monitoring during MRI is essential because unrecognized PoR may inhibit pacing or accelerate battery depletion due to high pacing output.
The initial experience with left atrial esophageal fistula (LAEF) secondary to atrial fibrillation (AF) ablation procedures revealed a near-universal mortality. A comprehensive description of the ...principles of LAEF repair in the modern era and its resulting impact on morbidity and mortality are lacking in the literature.
To describe the presentation, surgical management, and outcomes of patients with LAEF.
A retrospective cohort analysis of 29 patients was performed, including previously unpublished cases of surgically repaired LAEF from 4 institutions (n = 6), and all published cases of surgically repaired (n = 16) or stented (n = 7) LAEF.
The mean age was 55 ± 13 years, and 75% were men who were undergoing radiofrequency energy catheter ablation (n = 26), cryoablation (n = 1), high-intensity focused ultrasound ablation (n = 1), and surgical mini-MAZE procedure (n = 1) and presented 30 ± 12 days postablation procedure. Overall, 55% of the patients receiving an intervention for LAEF died (41% surgical repair; 100% stent). Patients who did not receive primary esophageal repair were more likely to experience postoperative complications, including mediastinitis, need for percutaneous endoscopic gastrostomy (PEG) feeds, esophageal stent, or death (P = .05). In addition, interposing tissue between the repaired esophagus and the left atrium resulted in fewer postoperative complications (P = .02).
While improved relative to initial reports, mortality associated with LAEF remains high after corrective intervention. Primary esophageal repair with the placement of tissue between the repaired esophagus and the left atrium may result in lower morbidity and mortality.
Magnetic resonance imaging (MRI) in patients with left ventricular (LV) leads may cause tissue or lead heating, dislodgment, venous damage, or lead dysfunction.
The purpose of this study was to ...determine the safety of MRI in patients with LV pacing leads.
Prospective data on patients with coronary sinus LV leads undergoing clinically indicated MRI at 3 institutions were collected. Patients were not pacemaker-dependent. Scans were performed under pacing nurse, technician, radiologist, and physicist supervision using continuous vital sign, pulse oximetry, and ECG monitoring and a 1.5-T scanner with specific absorption rate <1.5 W/kg. Devices were interrogated pre- and post-MRI, programmed to asynchronous or inhibition mode with tachyarrhythmia therapies off (if present), and reprogrammed to their original settings post-MRI.
MRI scans (n = 42) were performed in 40 patients with non-MRI conditional LV leads between 2005 and 2013 (mean age 67 ± 9 years, n = 16 40% women, median lead implant duration 740 days with interquartile range 125-1173 days). MRIs were performed on the head/neck/spine (n = 35 83%), lower extremities (n = 4 10%), chest (n = 2 5%), and abdomen (n = 1 2%). There were no overall differences in pre- and post-MRI interrogation LV lead sensing (12.4 ± 6.2 mV vs 12.9 ± 6.7 mV, P = .38), impedance (724 ± 294 Ω vs 718 ± 312 Ω, P = .67), or threshold (1.4 ± 1.1 V vs 1.4 ± 1.0 V, P = .91). No individual LV lead changes required intervention.
MRI scanning was performed safely in non-pacemaker-dependent patients with coronary sinus LV leads who were carefully monitored during imaging without clinically significant adverse effect on LV lead function.
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