Journal of Innovations in Cardiac Rhythm Management最新文献

Functional atrial mapping is an emerging mapping modality to predict potential critical sites with a role in the maintenance of tachycardia. We report a case of atrial late activation mapping under sinus rhythm predicting the critical isthmus of a left atrial tachycardia. Our findings demonstrate the utility of an atrial isochronal late-activation mapping approach to predict the critical isthmus of re-entry.

An 80-year-old man with no previous history of catheter ablation or cardiac surgery underwent catheter ablation for atrial tachycardia (AT). We suspected that the mechanism causing AT was re-entry indicated by the entrainment phenomenon during AT and through activation mapping with a 3-dimensional mapping system (EnSite™ X EP system; Abbott, Chicago, IL, USA). We used a multipolar catheter (Advisor™ HD Grid Mapping Catheter; Abbott) inserted into the superior vena cava (SVC) to accomplish activation mapping. The AT circuit was localized inside the SVC with a fractionated potential recorded on its right lateral wall. A similar fractionated potential was observed in the surrounding area. These areas functioned as the critical isthmus of the AT. Radiofrequency (RF) catheter ablation at these sites eliminated the tachycardia. After RF delivery, no tachycardia was induced by programmed stimulation, even during isoproterenol infusion. Consequently, there was no recurrence of tachycardia even after catheter ablation.

Protein-energy malnutrition (PEM), which leads to a reduced ability of tissues to regenerate and repair themselves, may exacerbate many chronic diseases, including atrial fibrillation (AF), which occurs as a response of the heart to chronic inflammation. However, population-based studies examining the association between PEM and the prevalence and health care burden of AF are lacking. The aim of this retrospective cohort study was to estimate the impact of PEM on the prevalence and clinical outcomes of hospitalization for AF. The National Inpatient Sample (NIS) 2016 and 2017 datasets were searched for data on hospitalized adult patients with AF as a principal diagnosis; we subsequently identified AF patients with and without PEM as a secondary diagnosis using International Classification of Diseases, Tenth Revision (ICD-10), codes. The primary outcome of our study was inpatient mortality, while the secondary outcomes were hospital length of stay (LOS), total hospital cost (THC), cardiogenic shock, pacemaker insertion, successful ablation, and restoration of cardiac rhythm. Propensity score-weighted analysis was used accordingly to adjust for confounders. Out of 821,630 AF hospitalizations, 21,385 (3%) had PEM. Hospitalization for AF with PEM led to a statistically significant increase in mortality (adjusted odds ratio [aOR], 2.30; 95% confidence interval [CI], 1.93-2.75; P < .001) with an adjusted increase in the THC of $15,113 (95% CI, 11,246-18,980; P < .001), a 2-day increase in the LOS (95% CI, 1.92-2.41; P < .001), increased odds of cardiogenic shock (aOR, 1.36; 95% CI, 1.01-1.85; P = .04), and decreased odds of undergoing successful ablation (aOR, .71; 95% CI,.56-.88; P = .002) and achieving the restoration of cardiac rhythm (aOR, 0.56; 95% CI, 0.49-0.0.63; P ≤ .001) compared to those without PEM. These results indicate that PEM is associated with worse in-hospital outcomes in patients with AF. This potential association suggests that nutritional rehabilitation may be essential for improving hospitalization outcomes in AF patients.

The Micra™ leadless pacemaker (Medtronic, Minneapolis, MN, USA) is indicated for the management of symptomatic bradycardia and advanced heart block. However, the safety of this procedure during pregnancy has not been studied. Here, we present a unique case of Micra™ leadless pacemaker implantation (MLP) in a 31 weeks pregnant patient with intermittent complete heart block who presented with multiple syncopal episodes. The patient underwent an MLP implantation with <40 mGy radiation exposure (about 0.6 min of total fluoroscopy time), which is deemed a negligible dose of radiation exposure during pregnancy. Her subsequent hospital course was uneventful, and she was safely discharged home and was able to continue her pregnancy and delivery without further syncopal episodes or incidence of heart block.

Cardiac memory is a common condition occurring after a period of abnormal depolarization, such as with right ventricular apical pacing. With restoration of normal conduction, the T-wave "remembers" the direction of the QRS vector of the previously aberrantly conducted complexes, creating diffusely inverted T-waves on the electrocardiogram. The presence of diffuse T-wave inversions with this phenomenon may be confused with myocardial ischemia and may continue to be present for several weeks after restoration of normal conduction. Here, an interesting electrocardiogram obtained after pacemaker implantation showing the opposite effect, ie, the finding of memory T-waves occurring during pacing after a period of intrinsic atrioventricular nodal conduction, is presented. In this case, the patient had an underlying left bundle branch block, which subsequently normalized as a result of conduction system pacing. The memory T-waves became evident after pacing was performed, suggesting a potential marker for restoration of the normal ventricular activation sequence with left bundle branch pacing and normalization of the baseline intraventricular conduction defect.

Heart block (HB) is one of the most serious arrhythmias. Higher degrees of HB-for example, trifascicular HB-result in a more intense patient condition. Atrial septal defects (ASDs) represent the most common congenital heart disease in adults. All ASDs generally result in a left-to-right shunt, commonly causing right-side enlargement and dilation and, to a lesser extent, left atrial enlargement. A 26-year-old woman presented to the physician outpatient clinic with a complicated ASD with trifascicular HB and severe mitral and tricuspid regurgitations. The trifascicular HB with valvular regurgitations resolved with congenital ASD closure; however, she was diagnosed with coronavirus disease 2019 (COVID-19)-associated cardiac strain 3 years later. Interventions included electrocardiography, oxygenation, echocardiography, and cardiovascular surgical repair. A dramatic electrocardiographic response and better clinical outcomes despite dilations of both atria were observed. Trifascicular HB is a newly recorded association after congenital ASDs in adults. The disappearance of trifascicular HB after surgical closure of the congenital ASD is an indicator of effective surgical repair. The occurrence of COVID-19 pneumonia later, with atrial dilations continuing after the infection, may be a constellation of risk factors for the observed cardiac strain.

Pulmonary vein isolation (PVI) is used for rhythm control in atrial fibrillation (AF). Posterior wall isolation (PWI) is often an adjunct to PVI. Successful PWI is limited by esophageal location, epicardial bridging signals, tissue thickness, and mapping catheter resolution. High-density grid mapping catheters can assist with PWI. Here, we report a case of a 71-year-old woman with persistent AF who underwent PVI and PWI with high-density grid mapping catheters, thus demonstrating the use of omnipolar technology in facilitating successful PWI.

Radiofrequency (RF) ablation can be a source of electromagnetic interference (EMI) for cardiovascular implantable electronic devices (CIEDs). The response of CIEDs to this type of EMI can be variable and unpredictable. We report a case with an uncommon response where there was a failure to deliver pacing pulses to both atrial and ventricular pacing leads during RF ablation close to the atrial lead even when the pacemaker was set to pace asynchronously. We also explain the mechanism behind this unusual pacemaker response.