Julianne H Spencer's research while affiliated with Medtronic and other places
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Publications (14)
Background:
A dilemma arises regarding the merits of conservative management vs. lead replacement and/or extraction when patients with a Medtronic Sprint Fidelis® lead undergo generator replacement. Conflicting reports suggest that the fracture rate may increase after generator change.
Objective:
To investigate the effect of generator replacemen...
The primary goal of this computational modeling study was to better quantify the relative distance of the phrenic nerves to areas where cryoballoon ablations may be applied within the left atria. Phrenic nerve injury can be a significant complication of applied ablative therapies for treatment of drug refractory atrial fibrillation. To date, publis...
The objective of this study was to quantitatively characterize anatomy of the human phrenic nerve in relation to the coronary venous system, to reduce undesired phrenic nerve stimulation during left-sided lead implantations.
We obtained CT scans while injecting contrast into coronary veins of 15 perfusion-fixed human heart-lung blocs. A radiopaque...
In recent years, the use of perfusion-fixed cadaveric specimens and isolated heart models has helped to develop an improved understanding of the device-tissue interface and has also contributed to the rapid evolution of surgically and percutaneously delivered cardiac therapies. This chapter describes a novel series of techniques utilized within the...
An anatomical understanding of human coronary arterial and venous systems is necessary for device development and therapy applications that utilize these vessels. We investigated the unique use of contrast-CT scans from perfusion-fixed human hearts for three-dimensional visualization and analysis of anatomical features of the coronary systems. The...
Characterize where the circumflex artery crosses between the coronary sinus and mitral valve in order to minimize the occurrence of coronary compression during percutaneous indirect mitral valve interventions.
Treatment of mitral valve regurgitation using an indirect percutaneous approach via access through the coronary sinus remains under active r...
This paper describes how the Atlas of Human Cardiac Anatomy website can be used to improve cardiac device design throughout the process of development. The Atlas is a free-access website featuring novel images of both functional and fixed human cardiac anatomy from over 250 human heart specimens. This website provides numerous educational tutorials...
Access to the coronary venous system is required for the delivery of several cardiac therapies including cardiac resynchronization therapy, coronary sinus ablation, and coronary drug delivery. Therefore, characterization of the coronary venous anatomy will provide insights to gain improved access to these vessels and subsequently improved therapies...
A detailed understanding of the complexity and relative variability within the human cardiac venous system is crucial for the development of cardiac devices that require access to these vessels. For example, cardiac venous anatomy is known to be one of the key limitations for the proper delivery of cardiac resynchronization therapy (CRT)(1) Therefo...
The coronary venous system is a highly variable network of veins that drain the deoxygenated blood from the myocardium. The system is made up of the greater cardiac system, which carries the majority of the deoxygenated blood to the right atrium, and the smaller cardiac system, which drains the blood directly into the heart chambers. The coronary v...
Citations
... Few studies have evaluated patients with box or generator changes after ICD implantation. Studies have been conducted that evaluate the cost-effectiveness of upgrade at time of generator change [4], infections [5], lead survival [6], generator longevity in CRT-D devices [7], appropriateness of generator replacement in Brugada syndrome [8] and arrhythmic events with CRT elective generator change [9] and complications with repeat ICD procedures [10]. The literature on patient characteristics, therapy received and outcomes after one or more ICD generator changes from contemporary practice is not well known. ...
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... Detailed studies of the anatomy of the cervical phrenic nerve (Banneheka, 2008;Canella et al., 2010;Kelley, 1950;Paraskevas et al., 2011;Rajanna, 1947) are important to improve the safety of cervical surgery, locoregional anesthesia and central venous catheterization procedures. Precise descriptions of the proximal intrathoracic (Goff et al., 2016) and distal (Wang et al., 2016) portions of the phrenic nerve have also been proposed in order to reduce the risk of phrenic nerve damage during arrhythmia or flutter ablations (review in Cappato et al., 2010). Anatomical studies have focused on the distal divisions of the phrenic nerve (e.g. ...
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... 38 In addition, despite being an extrapericardial structure, the PN is, on average, less than 5 mm distant from the epicardial aspect of the LV (3.4 mm from the middle cardiac vein, 6.3 mm from the anterior intraventricular vein). 36,39 As a result of its anatomic relationship, and the marginal incidence of VT arising from the margin of the RV, the left PN is more likely to be injured during epicardial ablations (see Table 1). ...
Reference: Epicardial Ablation Complications
... Once a surgical plane of anaesthesia is sustained, a medial sternotomy is performed and a standard cardioplegia solution is rapidly administered (at ~150 mmHg via the aortic cannula) to depolarise the heart. Then, the isolated heart is reanimated using previously published Visible Heart ® methodologies [3][4][5][6][7] . Briefly, the great vessels of the heart are cannulated and attached to the Visible Heart ® apparatus. ...
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... Mitral annulus anatomy as well as relationship with circumflex artery and coronary sinus should be evaluated to assess procedural feasibility and predict procedural success and complications, taking into account the high anatomical variability [45] . ...
... In (a) we see a cardiac short-axis MRI of heart, centred in the heart, and cropped to frame the right and left ventricles; in (b) the left ventricle myocardium is highlighted, and (c) only shows the left ventricle myocardium segmentation mask. Images (a-c) are adapted from the dataset [21] and d is reproduced from the Atlas of Human Cardiac Anatomy website [20] Content courtesy of Springer Nature, terms of use apply. Rights reserved. ...
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... В исследовании J. H. Spencer и соавт. [63] проводилось размещение канюли в КС с помощью катетера с венограммным баллоном и введения контрастного вещества в венозную систему с получением компьютерных томографических изображений. С помощью реконструированной анатомии оценивались расстояния до КС, угол ветви, длина дуги, извилистость, количество ветвей и диаметр ости для каждой крупной коронарной вены. ...
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... Van de Veire et al. demonstrated that the diameter of the proximal GCV was 7.2 ± 1.4 mm on average, while the distal was 4.9 ± 1.1 mm) [16]. A study using contrast-computed tomography showed a thin lumen of AIV with a mean ostial diameter of 4.46 mm [17]. Summit-CV is the thinnest part of the TAODGCV, and Komatsu et al. reported that due to the very thin lumen of Summit-CV in some patients, only the 2-F mapping catheter could access this site [18]. ...
... It ascends along the anterior interventricular groove to the base of the heart, while in cardiology and radiology, the initial segment of the great cardiac vein (from the apex of the left ventricle to the LVS area) is named the anterior intraventricular vein [22]. By definition, the anterior intraventricular vein originates at the lower or middle third of the anterior interventricular groove, follows the groove adjacent to the left anterior descending artery and angulates laterally toward the heart's base to form the great cardiac vein [7,32]. The point of transition between the anterior interventricular vein and the great cardiac vein lies inside the LVS, and arguably, it is a significant source of epicardial idiopathic ventricular arrhythmias [33]. ...
