Cardiac radioablation in the treatment of ventricular tachycardia.

Cardiac radioablation with SBRT is a very promising non-invasive modality for the treatment of refractory VT and potentially other cardiac arrhythmias. Initial reports indicate that it is relatively safe and associated with excellent responses, particularly in reduction of ICD-related events, need for anti-arrhythmic medications, and resulting in significantly improved quality of life for patients. Establishment of objective criteria for candidates for cardiac radioablation will accelerate the adoption of this important radiation therapy modality in the treatment of refractory VT and other cardiac arrhythmias in the coming years. In addition, in order to develop more prospective safety and efficacy data, treatment of patients should ideally be performed in the context of clinical trials or prospective registries at, or in collaboration with, experienced centers. Taken together, the future of cardiac radioablation is rich and worthy of further investigation to become a standard treatment in the armamentarium against refractory VT.

Method and Atlas to Enable Targeting for Cardiac Radioablation Employing the American Heart Association Segmented Model.

PURPOSE: Cardiac radioablation using stereotactic body radiation therapy is gaining popularity as a noninvasive treatment for otherwise refractory ventricular arrhythmias. As radiation oncologists might be unaccustomed to the lexicon used by cardiologists to describe the location of arrhythmogenic foci, a preliminary guide to cardiac-specific anatomy and orientation is needed to foster effective communication between the radiation oncologist and cardiology team. METHODS AND MATERIALS: Electrocardiogram-gated and respiratory-gated computed tomography imaging was acquired per institutional protocol. Additional relevant imaging modalities are described. The American Heart Association 17-segment model is described in detail because this framework is used frequently by cardiologists to describe the location left ventricular abnormalities. RESULTS: A step-by-step guide is provided for properly rotating the heart from standard orthogonal views obtained during radiation simulation to the cardiac-specific orientation needed to appreciate the 17-segment model. Once the proper configuration is achieved, the location of each segment is defined in detail. CONCLUSIONS: This atlas serves as an introduction to the relevant anatomy and principles, and it provides a suggested approach to help delineate cardiac radioablation targets using the established American Heart Association 17-segment model.

Tine-Based Leadless Pacemaker: Strategies for Safe Implantation in Unconventional Clinical Scenarios.

Leadless pacemakers (LPs) have emerged as a meaningful alternative to transvenous pacemakers for single-ventricular pacing. LPs eliminate many of lead- and pocket-associated complications observed with transvenous pacemakers. Owing to the lack of atrioventricular synchronous pacing until recently, the use of LP was generally reserved for those patients who either required minimal ventricular pacing or had permanent atrial fibrillation. The only commercially available LP is the Micra transcatheter pacing system (Micra-TPS, Medtronic Inc. Fridley, Minnesota), which requires insertion of a 27-F (outer diameter) introducer sheath in the femoral vein. The LP is delivered to the right ventricle using a 23-F delivery catheter. Owing to the need for a large-bore sheath, the pivotal studies for the Micra transcatheter pacing system excluded patients with indwelling inferior vena cava filters and included only a few patients with bioprosthetic or repaired tricuspid valve. Subsequent real-world experience has demonstrated the overall safety and feasibility of LP placement, and use in various unconventional clinical settings has been validated, albeit with specific precautions. Additionally, incorporation of adjunctive techniques and strategies can improve the safety of the procedure in routine clinical settings as well. The objective of this state-of-the-art review is to highlight the key procedural elements to facilitate safe and efficient implantation of LP in routine as well as in unique clinical settings.

Comprehensive strategies to minimize radiation exposure during Interventional electrophysiology procedures: state-of-the-art review.

INTRODUCTION: Cardiac electrophysiology (EP) procedures are frequently performed in patients with cardiac arrhythmias, chronic heart failure, and sudden cardiac death. Most EP procedures involve fluoroscopy, which results in radiation exposure to physicians, patients, and EP lab staff. Accumulated radiation exposure is a known health detriment to patients and physicians. AREA COVERED: This review will summarize radiation exposure, dose metrics, complications of radiation exposure, factors affecting radiation exposure, minimizing radiation exposure, zero or near-zero fluoroscopy strategies, and up-to-date research in the area of reducing radiation exposure and best practices. EXPERT COMMENTARY: Comprehensive strategies should be implemented in EP laboratories to minimize radiation exposure with standard fluoroscopy. There are routine techniques that can mitigate significant amounts of radiation exposure using standard equipment within the EP lab. The operators need to emphasize that EP practices routinely incorporate non-ionizing radiation sources for cardiac imaging (e.g. magnetic resonance imaging, advanced electroanatomical mapping systems, intracardiac ultrasonography) in addition to other novel technologies to mitigate radiation exposure to patients and physicians.

BioMonitor 2 in-office setting insertion safety and feasibility evaluation with device functionality assessment: results from the prospective cohort BioInsight study.

BACKGROUND: Insertable cardiac monitors are utilized for the diagnosis of arrhythmias and traditionally have been inserted within hospitals. Recent code updates allow for reimbursement of office-based insertions; however, there is limited information regarding the resources and processes required to support in-office insertions. We sought to determine the safety and feasibility of in-office insertion of the BioMonitor 2 and better understand in-office procedures, including patient selection, pre-insertion protocols, resource availability, and staff support. METHODS: Patients meeting an indication for a rhythm monitor were prospectively enrolled into this single-arm, non-randomized trial. All patients underwent insertion in an office setting. Two follow-up visits at days 7 and 90 were required. Information on adverse events, device performance, office site preparations, and resource utilization were collected. RESULTS: Eighty-two patients were enrolled at six sites. Insertion was successful in all 77 patients with an attempt. Oral anticoagulation was stopped in 20.8% of patients and continued through insertion in 23.4%, while prophylactic antibiotics were infrequently utilized (37.7% of study participants). On average, the procedure required a surgeon plus two support staff and 35 min in an office room to complete the 8.4 min insertion procedure. The mean R-wave amplitude was 0.77 mV at insertion and 0.67 mV at 90-days with low noise burden (2.7%). There were no procedure related complications. Two adverse events were reported (event rate 2.7% [95% CI 0.3, 9.5%]). CONCLUSIONS: In-office insertion of the BioMonitor 2 is safe and feasible. Devices performed well with high R-wave amplitudes and low noise burden. These results further support shifting cardiac monitor insertions to office-based locations. TRIAL REGISTRATION: clinicaltrials.gov, NCT02756338. Registered 29 April 2016.

Implantation of subcutaneous defibrillator is feasible and safe with monitored anesthesia care.

BACKGROUND: The perioperative anesthesia care during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation is still evolving. OBJECTIVE: To assess the feasibility and safety of S-ICD implantation with monitored anesthesia care (MAC) versus general anesthesia (GA) in a tertiary care center. METHODS: This is a single-center retrospective study of patients undergoing S-ICD implantation between October 2012 and May 2019. Patients were categorized into MAC and GA group based on the mode of anesthesia. Procedural success without escalation to GA was the primary endpoint of the study, whereas intraprocedural hemodynamics, need of pharmacological support for hypotension and bradycardia, length of the procedure, stay in the post-anesthesia care unit, and postoperative pain were assessed as secondary endpoints. RESULTS: The study comprises 287 patients with MAC in 111 and GA in 176 patients. Compared to MAC, patients in GA group were younger and had a higher body mass index. All patients had successful S-ICD implantation. Only one patient (0.9%) in the MAC group was converted to GA. Despite a similar baseline heart rate (HR) and mean arterial blood pressure (MAP) in both groups, patients with GA had significantly lower HR and MAP during the procedure and more frequently required pharmacological hemodynamic support. Length of the procedure, stay in the postanesthesia care unit, and postoperative pain was similar in both groups. CONCLUSION: This retrospective experience suggests that implantation of S-ICD is feasible and safe with MAC. Use of GA is associated with more frequent administration of hemodynamic drugs during S-ICD implantation.

Feasibility of concomitant vacuum-assisted removal of lead-related vegetations and cardiac implantable electronic device extraction.

BACKGROUND: Cardiac implantable electronic device (CIED) infections associated with large, mobile vegetation adds to the complexity of lead extraction and is associated with significant patient morbidity and mortality. OBJECTIVE: To show the feasibility of concomitant cardiovascular implantable electronic device extraction and vacuum-assisted removal of lead-related vegetations. METHODS: This is a single-center retrospective case series of consecutive patients with persistent bacteremia, sepsis, or endocarditis despite medical therapy who have vegetations >2 cm and subsequently underwent immediate CIED lead extraction after debulking with vacuum-assisted suction. RESULTS: Eight patients underwent successful removal of 17 leads immediately after debulking of vegetations with vacuum-assisted device suction. Debulking procedure was not successful in 1 patient due to inability to direct the vacuum suction device into proper position. There were no intraprocedure complications related to the vacuum-assisted debulking. One patient required open sternotomy for tear of the coronary sinus ostium related to extraction of a left ventricular pacing electrode. There was no mortality within 30 days of the procedure. CONCLUSIONS: Based upon these clinical results, it is feasible for patients with infected CIED systems that have large right-sided vegetations to undergo vacuum-assisted debulking then immediately followed by percutaneous CIED removal in whom surgical removal is considered high risk.

Techniques for successful early retrieval of the Micra transcatheter pacing system: A worldwide experience.

BACKGROUND: Experience with retrieval of the Micra transcatheter pacing system (TPS) is limited because of its relatively newer technology. Although abandonment of the TPS at end of life is recommended, certain situations such as endovascular infection or device embolization warrant retrieval. OBJECTIVE: The purpose of this study was to report the worldwide experience with successful retrieval of the Micra TPS. METHODS: A list of all successful retrievals of the currently available leadless pacemakers (LPs) was obtained from the manufacturer of Micra TPS. Pertinent details of retrieval, such as indication, days postimplantation, equipment used, complications, and postretrieval management, were obtained from the database collected by the manufacturer. Other procedural details were obtained directly from the operators at each participating site. RESULTS: Data from the manufacturer consisted of 40 successful retrievals of the Micra TPS. Operators for 29 retrievals (73%) provided the consent and procedural details. Of the 29 retrievals, 11 patients underwent retrieval during the initial procedure (immediate retrieval); the other 18 patients underwent retrieval during a separate procedure (delayed retrieval). Median duration before delayed retrieval was 46 days (range 1-95 days). The most common reason for immediate retrieval was elevated pacing threshold after tether removal. The most common reasons for delayed retrieval included elevated pacing threshold at follow-up, endovascular infection, and need for transvenous device. Mean procedure duration was 63.11 ± 56 minutes. All retrievals involved snaring via a Micra TPS delivery catheter or steerable sheath. No serious complications occurred during the reported retrievals. CONCLUSION: Early retrieval of the Micra TPS is feasible and safe.

Prompt Recognition of Left Ventricular Free-Wall Rupture Aided by the Use of Contrast Echocardiography.

In the modern period of reperfusion, left ventricular free-wall rupture occurs in less than 1% of myocardial infarctions. Typically, acute left ventricular free-wall rupture leads to sudden death from immediate cardiac tamponade. We present the case of a 59-year-old woman who sustained a posterior-wall myocardial infarction and subsequent cardiac arrest with pulseless electrical activity. A bedside transthoracic echocardiogram showed pericardial effusion with cardiac tamponade. Emergency pericardiocentesis yielded 500 mL of blood, and spontaneous circulation returned. Contrast-enhanced echocardiograms revealed inferolateral akinesis and a new, small myocardial slit with systolic extrusion of contrast medium, consistent with left ventricular free-wall rupture. During immediate open-heart surgery, a small hole in an area of necrotic tissue was discovered and repaired. This case highlights the usefulness of bedside contrast-enhanced echocardiography in confirming acute left ventricular free-wall rupture and enabling rapid surgical treatment.

Patient characteristics and predictors of mortality associated with pericardial decompression syndrome: a comprehensive analysis of published cases.

BACKGROUND: Pericardial decompression syndrome (PDS) is a rare and potentially fatal complication of pericardial drainage, either by needle pericardiocentesis or surgical pericardiostomy. It manifests with paradoxical hemodynamic deterioration and/or pulmonary edema, commonly associated with ventricular dysfunction. We sought to elucidate factors associated with mortality in PDS. METHODS: MEDLINE was systematically searched for PDS case reports and case series published between 1983 and 2013. For this analysis, clinical variables, echocardiographic and hemodynamic variables, details of drainage procedure and clinical outcomes were collected for each case. RESULTS: A total of 35 cases (12 male, 23 female) were identified. PDS developed after pericardiocentesis, pericardiostomy, or both, in 18, 16, and one patients, respectively. Cardiac tamponade was the indication in 33 cases (94%). The mean age was 47 ± 17 years. The mean amount of effusion drained was 888 mL. The minimum amount of effusion drained was 450 mL. The onset of PDS after the procedure varied widely, ranging from 'immediate' to 48 hours. Presentations included 10 (29%) with cardiogenic pulmonary edema without shock, 14 (40%) with left ventricular failure, three (9%) with right ventricular failure, seven (20%) with biventricular failure, and one (3%) with non-cardiogenic pulmonary edema. Ten patients (29%) died of PDS. Mortality was associated only with surgical drainage (p<0.001). Severe LV dysfunction normalized in PDS survivors. CONCLUSIONS: PDS is a rare complication of pericardial drainage with a high mortality rate. Surgical pericardiostomy was associated with mortality in PDS.

What intensivists need to know about hemophagocytic syndrome: an underrecognized cause of death in adult intensive care units.

Hemophagocytic syndrome, also known as hemophagocytic lymphohistiocytosis (HLH), is a rare and frequently fatal disorder caused by an uncontrollable and ineffective systemic immune response. Patients initially present with fever, cytopenia, and hepatosplenomegaly, and subsequently develop multiorgan failure (MOF). Hemophagocytosis can be found on biopsy specimen but is not required. Acquired forms of HLH can occur in apparently healthy adults, while children present more often with an inherited form of the disease. Since HLH often presents with sepsis-like symptoms and organ dysfunction, patients are usually treated for presumed sepsis, which inevitably leads to delayed diagnosis and treatment. Intensivists need to have a low threshold for suspecting this disorder when previously healthy individuals present with a fulminant sepsis-like syndrome, which are unresponsive to conventional treatment. We present 3 patients with HLH who were admitted to our adult medical intensive care unit (MICU) over a 2-year period with fatal outcomes and emphasize the diagnostic importance of markedly elevated serum ferritin levels and the need for tissue biopsy in making an accurate diagnosis in a timely manner.