Infective endocarditis associated with left atrial appendage occlusion device: a contemporary systematic review.

BACKGROUND: Data are limited regarding infective endocarditis (IE) complicating left atrial appendage occlusion (LAAO) device procedures. This systematic review examines the etiology, diagnosis, and management of infective endocarditis (IE) following LAAO. METHODS: A comprehensive search of six databases was performed between 2007 and 2022. In selecting studies, articles were included if they provided information about IE complicating LAAO, with relevant clinical and imaging details. Articles were excluded if they were editorials, study protocols, letters, or abstracts. RESULTS: We identified seven cases of IE complicating LAAO published between 2007 and 2022, from the United States and Europe, highlighting the exceedingly rare reported incidence of the condition. Staphylococcus aureus is the predominant organism implicated in LAAO infections. Echocardiography is a key imaging modality for diagnosing LAAO IE. Both antibiotic therapy and surgical intervention in appropriate patients are important for managing LAAO device-related IE. CONCLUSIONS: The limited data in the current literature regarding LAAO IE underscores the need for prospective clinical trials to establish evidence-based guidelines for infection prophylaxis, diagnosis, and management. Our findings emphasize the importance of vigilance for device-related infections, especially as the use of LAAO devices continues to grow worldwide.

Trends and Outcomes of Left Atrial Appendage Occlusion in Renal and Liver Transplant Recipients: Insights From the United States National Inpatient and Readmission Database.

Left atrial appendage occlusion using the Watchman device has emerged as an alternative treatment strategy for preventing strokes in patients with atrial fibrillation. However, there is no data on its safety and clinical outcomes in prior renal or liver transplant recipients. We included a total of 61,995 patients from the National Inpatient Sample (NIS, in-hospital outcomes) and 55,048 patients from the National Readmission Database (NRD, 30-day outcomes) who underwent percutaneous left atrial appendage occlusion (LAAO). From this group, 0.65% (n=405) and 0.62% (n=339) were renal and liver transplant recipients in NIS and NRD respectively. Transplant recipients were younger compared with non-transplant recipients (mean age 69 vs 77 years, P=<0.01). There was little difference in terms of in-hospital mortality (0% vs 0.2%, P=0.43), major complications (6.2% vs 5.6%, P=0.61), cardiovascular complications (2.5% vs 2.8%, P=0.73), neurological complications (1.2% vs 0.7%, P=0.21) or bleeding complications (1.2% vs 0.7%, P=0.99) between transplant vs. non-transplant patients. Based on the NRD database, 30-day readmission rate was not meaningfully different for transplant recipients undergoing LAAO (9.44%) when compared to non-transplant patients (8.12%, [log-rank, P=0.56]). There was no difference between 30-day major or cardiovascular complications, however vascular complication rates were significantly higher for transplant recipients (OR 2.56, 95% CI [(1.66-3.47]). Our study findings suggest that LAAO may be safe for patients with a prior renal or liver transplant in terms of major complications, cardiovascular complications, and all-cause readmission rates. However vascular complications may be higher in transplant recipients. Further large-scale studies are needed to confirm these findings.

A case of cardiac sarcoidosis with successful heart transplantation after COVID-19 infection.

Arrhythmogenic right ventricular cardiomyopathy and cardiac sarcoidosis can both present with ventricular tachycardia. We report a case of a patient whose histological diagnosis was not only confirmed by the transplanted heart but who also underwent successful transplantation after overcoming COVID-19. .

Management of peri-device leak following left atrial appendage closure: A systematic review.

OBJECTIVE: This study aimed to examine the cumulative experience of peri-device leak (PDL) closure following left atrial appendage (LAA) closure. BACKGROUND: The management of PDL following LAA closure remains controversial. While PDL closure has been proposed, procedural features and clinical outcomes have not been well established. METHODS: A systematic review of all published cases of PDL closure with available anatomical, procedural, and clinical outcomes was performed. RESULTS: We identified 18 indexed publications and 110 cases between April 2013 and March 2020. 71 patients (mean age 72 ± 8 yrs), met study criteria and were included. PDL closure was most common in males, bilobar LAA morphology, and after Watchman procedures. The mean PDL size was 7.6 ± 5.8 mm (range 2-26 mm). Leaks were classified according to size: small (<5 mm; 45%), moderate (≥5-9 mm; 25%), and large (≥10 mm; 30%). Endovascular coils and endovascular plugs were used to close both small and moderate sized leaks, and second LAA closure devices were exclusively used for large PDLs. Successful PDL closure occurred in 90%, and was similar between PDL sizes and types of occluder used. Procedural complication rates were uncommon (2.8%). No strokes were reported following PDL closure at 6 months. CONCLUSIONS: In patients with PDL for whom discontinuation of OAC may be considered unsafe, percutaneous closure using a tailored approach with either endovascular coils, plugs, or second occluder represents a safe, and feasible alternative associated with favorable clinical outcomes.

Ethanol infusion in the vein of Marshall leads to parasympathetic denervation of the human left atrium: implications for atrial fibrillation.

OBJECTIVES: This study sought to determine whether ethanol infusion in the vein of Marshall (VOM) can ablate intrinsic cardiac nerves (ICN). BACKGROUND: ICN cluster around the left atrial epicardium and are implicated in the genesis of atrial fibrillation (AF). METHODS: Patients undergoing catheter AF ablation underwent adjunctive ethanol injection in the VOM. A multipolar catheter was introduced in the VOM and used for high-frequency stimulation (HFS), either as HFS with P-wave synchronized (SynchHFS), 30 pulses, 100 Hz (n = 8) or as HFS with 3 to 10 s bursts (BurstHFS), 33 Hz (n = 72) at 25 mA for 1-ms duration. Atrioventricular (AV) nodal conduction slowing (asystole >2 s or R-R interval prolongation >50%) and AF inducibility were assessed before and after VOM ethanol infusion. Up to 4 1-ml infusions of 98% ethanol were delivered via an angioplasty balloon in the VOM. RESULTS: SynchHFS induced AF in 8 of 8 patients. In 4 of 8 AF initiated spontaneously without VOM capture. No parasympathetic responses were elicited by SynchHFS. BurstHFS was performed in 32 patients undergoing de novo AF ablation (Group 1) and 40 patients undergoing repeat ablation (Group 2). Parasympathetic responses were found in all 32 Group 1 patients and in 75% of Group 2 patients. After VOM ethanol infusion, parasympathetic responses were abolished in all patients (both groups). There were no acute complications related to VOM ethanol infusion. CONCLUSIONS: The VOM contains ICN that connect with the AV node and can trigger AF. Retrograde ethanol infusion in the VOM reliably eliminates local ICN responses. The VOM is a vascular route for ICN-targeting therapies.

Effect of defibrillation threshold testing-induced ventricular fibrillation on renal function.

INTRODUCTION: The effect of defibrillation threshold (DFT) testing with induction of ventricular fibrillation (VF) on renal function is currently unknown. This study examined the acute effect of DFT testing on renal function in patients undergoing implantable cardioverter defibrillator (ICD) implantation. METHODS AND RESULTS: We performed a prospective cohort study of 148 consecutive patients who underwent ICD implantation from January 1, 2007 to May 30, 2008. Patients were assigned to one of two cohorts: a DFT group who underwent DFT testing at device implantation and a no-DFT group that was not tested. Baseline and 24-h postprocedure renal function were assessed with measurements of serum creatinine and estimated glomerular filtration rate (GFR) by the Modified Diet in Renal Disease equation. Changes in serum creatinine and estimated GFR were compared between cohorts. Ninety-eight patients (66%) underwent DFT testing (average VF induction count, 1.5 ± 0.9; mean VF duration, 10 ± 4 s). Fifty patients (34%) were not tested. Patients in the no-DFT group had lower mean left ventricular ejection fraction, higher New York Heart Association class, higher atrial fibrillation incidence, and greater intravenous contrast utilization at device implant. Baseline and postprocedure serum creatinine values were similar between groups (baseline, 1.25 ± 0.45 mg/dL; post-ICD, 1.26 ± 0.5 mg/dL). Baseline GFR was lower in the DFT cohort (55.2 ± 18.8 mL/min/BSA vs 63.7 ± 22.7 mL/min/BSA, p = 0.023). No significant differences between groups were observed in the mean change in serum creatinine or estimated GFR. CONCLUSIONS: DFT testing at the time of ICD implantation is not associated with acute adverse effects on renal function.

Ethanol infusion in the vein of Marshall facilitates mitral isthmus ablation.

BACKGROUND: Treatment of perimitral flutter (PMF) requires bidirectional mitral isthmus (MI) block, which can be difficult with radiofrequency ablation (RFA). The vein of Marshall (VOM) is located within the MI. OBJECTIVE: To test whether VOM ethanol infusion could help achieve MI block. METHODS: Perimitral conduction was studied in patients undergoing ablation of atrial fibrillation. Group 1 included 50 patients with a previous atrial fibrillation ablation undergoing repeat ablation, 30 of whom had had MI ablation. Spontaneous (8 of 50) or inducible PMF (21 of 50) was confirmed by activation mapping. Group 2 included 21 patients undergoing de novo VOM ethanol infusion. The VOM was cannulated with a quadripolar catheter for pacing and with an angioplasty balloon to deliver up to four 1-mL infusions of 98% ethanol. Voltage maps were created before and after VOM ethanol infusion. Bidirectional MI block was verified by differential pacing. RFA times required to achieve it were assessed. RESULTS: In group 1, VOM ethanol infusion acutely terminated PMF in 5 of 29 patients. RFA needed to achieve bidirectional MI block was 2.2 ± 1.6 minutes. Presence of PMF or previous MI ablation did not affect RFA times. In group 2, RFA needed to achieve bidirectional MI block was 2.0 ± 1.6 minutes (P = NS). Five patients had bidirectional MI block achieved solely by VOM ethanol infusion without RFA. In both groups, ablation after VOM ethanol infusion was required in the annular aspect of the MI. There were no acute complications. CONCLUSION: VOM ethanol infusion is useful in the treatment of PMF and assists in reliably achieving bidirectional MI block.

Role of the vein of Marshall in atrial fibrillation recurrences after catheter ablation: therapeutic effect of ethanol infusion.

UNLABELLED: Vein of Marshall Ethanol in Recurrent AF. INTRODUCTION: Atrial fibrillation (AF) or flutter can recur after pulmonary vein (PV) antral isolation (PVAI). The vein of Marshall (VOM) has been linked to the genesis of AF. We hypothesized that the VOM may play a role in AF recurrences and that VOM ethanol infusion may have therapeutic value in this setting. METHODS AND RESULTS: Sixty-one patients with recurrent AF or flutter after PVAI were studied. The VOM was successfully cannulated in 54; VOM and PV electrograms were recorded, and differential PV-VOM pacing was performed. VOM signals were present in all patients; however, VOM triggers of AF could not be demonstrated. VOM tachycardia was present in 1 patient. Left inferior (LIPV) and left superior (LSPV) reconnection was present in 32 and 30 patients, respectively. Differential pacing in VOM and LIPV showed VOM-mediated LIPV reconnection in 5/32 patients. In others, VOM and PV connected indirectly via left atrial tissues. Up to four 1 cc infusions of 98% ethanol were delivered in the VOM. Regardless of the reconnection pattern, ethanol infusion eliminated LIPV and LSPV reconnection in 23/32 and 13/30 patients, respectively. Ethanol terminated VOM and LIPV tachycardias in 2 patients. There were no acute procedural complications. CONCLUSIONS: VOM signals are consistently present in recurrent AF. VOM may rarely play a role in PV reconnection. However, VOM ethanol infusion can be useful in patients with recurrent AF after PVAI, assisting in achieving redisconnection of reconnected left PVs.

Ranolazine safely decreases ventricular and atrial fibrillation in Timothy syndrome (LQT8).

Long QT eight (LQT8), otherwise known as Timothy syndrome (TS), is a genetic disorder causing hyper-activation of the L-type calcium channel Cav 1.2. This calcium load and the resultant increase in the QT interval provide the substrate for ventricular arrhythmias. We previously presented a case in a patient with TS who had a profound decrease in his burden of ventricular arrhythmias after institution of an L-type calcium channel blocker. Although this patient's arrhythmia burden had decreased, he displayed an increasing burden of atrial fibrillation and still had bouts of ventricular fibrillation requiring defibrillator therapy. Basic research has recently shown that ranolazine, a multipotent ion-channel blocker, may be of benefit in patients with LQT8 syndrome. This case report details the decrease of atrial fibrillation and ventricular fibrillation events in our LQT8 patient with the addition of ranolazine.

Robotic catheter ablation of left ventricular tachycardia: initial experience.

BACKGROUND: Catheter ablation of ventricular tachycardia (VT) can be technically challenging due to difficulty with catheter positioning in the left ventricle (LV) and achieving stable contact. The Hansen Sensei Robotic system (HRS) has been used in atrial fibrillation but its utility in VT is unclear. OBJECTIVE: The purpose of this study was to test the technical feasibility of robotic catheter ablation of LV ventricular tachycardia (VT) using the HRS. METHODS: Twenty-three patients underwent LV VT mapping and ablation with the HRS via a transseptal, transmitral valve approach. Nineteen patients underwent substrate mapping and ablation (18 had ischemic cardiomyopathy, 1 had an apical variant of hypertrophic cardiomyopathy). Four patients had focal VT requiring LV VT mapping and ablation. Procedural endpoints included substrate modification by endocardial scar border ablation and elimination of late potentials, or elimination of inducible focal VT. RESULTS: Mapping and ablation were entirely robotic without requiring manual catheter manipulation in all patients and reaching all LV regions with stable contact. Fluoroscopy time of the LV procedure was 22.2 ± 11.2 minutes. Radiofrequency time was 33 ± 21 minutes. Total procedural times were 231 ± 76 minutes. Complications included a left groin hematoma (opposite to the HRS sheath), 1 pericardial effusion without tamponade that was drained successfully, and transient right ventricular failure in a patient with previous left ventricular assist device. At 13.4 ± 6.7 months of follow-up (range 1-19 months), recurrence of VT occurred in 3 of 23 patients. CONCLUSION: Our initial experience suggests that the HRS allows successful mapping and ablation of LV VT.

Medtronic Sprint Fidelis lead recall: determining the initial 5-year management cost to Medicare.

BACKGROUND: The Medtronic Sprint Fidelis defibrillator lead has a high failure rate and was recalled in October 2007. OBJECTIVE: The purpose of this study was to determine the incremental cost of the management of this lead to Medicare. METHODS: Real hospital cost data in U.S. dollars were collected on 32 patients with a Medtronic Sprint Fidelis lead who underwent lead revision. Of these patients, 15 were excluded because they had insurance coverage other than that provided by the Centers for Medicare & Medicaid Services. Seventeen patients with Medicare or Medicaid coverage underwent lead revision either electively (n = 6) or after being hospitalized for multiple shocks caused by a lead fracture (n = 11). Eighty-eight percent of the patients underwent extraction of the Fidelis lead at the time of lead revision. A decision model was made that outlines the potential management of the lead recall over time. The existing literature and Medtronic data were reviewed for parameters included in the decision model. The model assumed that 175,000 patients were alive with an implanted Fidelis lead at the time of the recall and that the annual failure rate will be 1.8% over the first 5 years. It was also assumed that 1% of patients without a lead fracture would also undergo elective lead revision each year and that the proportion of patients who would have the Fidelis lead extracted rather than abandoned would be 20:80. Estimates with ranges were used for parameters for which no data are available. The industry standard rate of lead failure was estimated based on the Sprint Quattro model 6947 lead, and this was subtracted from the estimated rates for the Sprint Fidelis lead such that the incremental cost of the lead failure could be estimated. RESULTS: The cost of lead revision trended higher when the Fidelis lead was extracted rather than abandoned ($45,077 ± $11,693 vs $33,802 ± $33, P = .20). In 5 years, the estimated cost impact of the Medtronic Sprint Fidelis lead recall to Medicare will be $287,000,000 (range $176,000,000-$1,186,000,000, October 2007 USD). CONCLUSION: The cost impact of managing a defibrillator lead with a high failure rate to Medicare will be substantial.

Late potential at the high ventricular septal level in a patient with Brugada: possible mechanisms and clinical implications.

The Brugada syndrome (BS) accounts for approximately 20% of cases of sudden cardiac death in patients with structurally normal hearts. The electrophysiologic basis for ST-segment elevation in the precordial electrocardiogram (ECG) leads that characterize the Brugada phenotype and its strong linkage to ventricular tachycardia (VT)/ventricular fibrillation is still a subject of controversy. Electrocardiographic manifestations of the syndrome have been attributed to one of two basic mechanisms: (1) conduction delay in the right ventricular (RV) epicardial-free wall in the region of the outflow tract or (2) premature repolarization of the RV epicardial action potential secondary to loss of the action potential dome. Signal-averaged ECG recordings have demonstrated late potentials that extend beyond the QRS complex in patients with the BS, especially in the anterior wall of the RV outflow tract. The basis for these epicardial late potentials remains a subject of interest among basic and clinical electrophysiologists. Endocardial late potentials in BS are even less well understood. We present a case of a patient with Brugada syndrome with a distinct endocardial late potential in the high ventricular septum coinciding with the ST-segment elevation. We discuss the possible mechanisms for this intracardiac finding and its clinical significance. We also review the effect of isoproterenol infusion on both the late potential and the surface ECG.

Comprehensive contrast and 3-dimensional echocardiographic imaging of left ventricular noncompaction cardiomyopathy.

A 62-year-old woman with a history of heart failure, hypertension and stroke presented to hospital with dyspnea. Transthoracic echocardiography revealed significant left ventricular dysfunction; with contrast-enhanced 2- and 3-dimensional echocardiography, extensive hypetrabeculation of the left ventricular myocardium was visualized, leading to a diagnosis of noncompaction cardiomyopathy. Apical thrombi were excluded with contrast imaging; however, the patient was systemically anticoagulated owing to the presence of noncompaction cardiomyopathy in the setting of prior stroke. This case report demonstrates remarkable imaging of the left ventricular myocardium achieved with contrast-enhanced 3-dimensional echocardiography in the setting of noncompaction cardiomyopathy.