Cybersecurity for Cardiac Implantable Electronic Devices: What Should You Know?

Medical devices have been targets of hacking for over a decade, and this cybersecurity issue has affected many types of medical devices. Lately, the potential for hacking of cardiac devices (pacemakers and defibrillators) claimed the attention of the media, patients, and health care providers. This is a burgeoning problem that our newly electronically connected world faces. In this paper from the Electrophysiology Section Council, we briefly discuss various aspects of this relatively new threat in light of recent incidents involving the potential for hacking of cardiac devices. We explore the possible risks for the patients and the effect of device reconfiguration in an attempt to thwart cybersecurity threats. We provide an outline of what can be done to improve cybersecurity from the standpoint of the manufacturer, government, professional societies, physician, and patient.     

Pulmonary vein total occlusion following catheter ablation for atrial fibrillation: clinical implications after long-term follow-up.

OBJECTIVES: We present the clinical course and management outcomes of patients with total pulmonary vein occlusion (PVO). BACKGROUND: Pulmonary vein occlusion is a rare complication that can develop after radiofrequency catheter ablation (RFA) of atrial fibrillation (AF). The long term follow-up data of patients diagnosed with PVO are minimal. METHODS: Data from 18 patients with complete occlusion of at least one pulmonary vein (PV) were prospectively collected. All patients underwent RFA for AF using different strategies between September 1999 and May 2004. Pulmonary vein occlusion was diagnosed using computed tomography (CT) and later confirmed by angiography when intervention was warranted. Lung perfusion scans were performed on all patients before and after intervention. The percent stenoses of the veins draining each independent lung were added together to yield an average cumulative stenosis of the vascular cross-sectional area draining the affected lung (cumulative stenosis index [CSI]). RESULTS: The patients' symptoms had a positive correlation with the CSI (r = 0.843, p < 0.05) and a negative one with the lung perfusion (r = -0.667, p < 0.05). A CSI > or =75% correlated well with low lung perfusion (<25%; r = -0.854, p < 0.01). Patients with a CSI > or =75% appeared to improve mostly when early (r = -0.497) and repeat dilation/stenting (r = 0.0765) were performed. CONCLUSIONS: Patients with single PVO are mostly asymptomatic and should undergo routine imaging. On the other hand, patients with concomitant ipsilateral PV stenosis/PVO and a CSI > or =75% require early and, when necessary, repeated pulmonary interventions for restoration of pulmonary flow and prevention of associated lung disease.     

Relationship between complex fractionated electrograms (CFE) and dominant frequency (DF) sites and prospective assessment of adding DF-guided ablation to pulmonary vein isolation in persistent atrial fibrillation (AF)

Dominant Frequency Mapping and Ablation . Background: Sites of high DF are potential targets for AF ablation, but it is unknown if addition of DF ablation can improve procedural outcome. Objectives: We sought to (1) examine the relationship between DF sites and complex fractionated electrograms (CFE) and (2) prospectively assess the long‐term outcome of adding DF ablation to pulmonary vein antral isolation (PVAI) for persistent AF. Methods: First, 20 patients with persistent AF who underwent previous CFE‐guided ablation and who had AF terminate during ablation were studied retrospectively (group I). Bipolar, 8‐second electrograms were collected by a circular catheter (288 ± 86 points/map). The EnSite NavX system allows for automated display of both CFE and DF maps. Electrograms with cycle length <120 ms were considered CFE and were compared to DF sites > 8 Hz (direct inverse relationship). Sites of AF termination were related to CFE and DF sites. Based on these observations, 30 different patients (group II) with persistent AF prospectively underwent DF‐guided ablation plus PVAI. They were followed every 3 months for 1 year (visit, Holter, ECG). These patients were compared to case‐matched controls undergoing PVAI alone (group III). Results: In group I, there was a significant, inverse correlation between DF and CFE values at each point (r =–0.24, P < 0.001). DF surface area was less than CFE area (27 ± 5 cm² vs 34 ± 4 cm², P = 0.03). CFE sites overlapped 48 ± 27% with the DF surface area. Nonoverlapping CFE sites were contiguous to DF sites. AF termination occurred where DF and CFE overlapped, and at these sites, DF was always greater than the mean DF for the map. In group II, all DF sites above the mean value were prospectively ablated during AF. AF termination was noted in only 2/30 (7%) patients. After DF ablation, PVAI was performed and termination increased to 4/30 patients (14%). At 1 year, freedom from atrial arrhythmia > 30 seconds occurred in 57% of DF+PVAI compared to 60% in patients receiving PVAI alone (P = 0.18). Conclusions: DF and CFE regions overlap only about 50%. AF termination retrospectively occurred on overlapping CFE/DF sites where DF was above the mean. However, prospective ablation of DF sites plus PVAI resulted in low AF termination rates, and did not improve 1 year success over PVAI alone. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1309‐1316, December 2011)     

Improving Death Certificate Completion: A Trial of Two Training Interventions

BACKGROUND AND OBJECTIVE: Effects of advances in Department of Veterans Affairs (VA) women’s health care on women veterans’ health care decision making are unknown. Our objective was to determine why women veterans use or do not use VA health care. DESIGN AND PARTICIPANTS: Cross-sectional survey of 2,174 women veteran VA users and VA-eligible nonusers throughout southern California and southern Nevada. MEASUREMENTS: VA utilization, attitudes toward care, and socio-demographics. RESULTS: Reasons cited for VA use included affordability (67.9%); women’s health clinic (WHC) availability (58.8%); quality of care (54.8%); and convenience (47.9%). Reasons for choosing health care in non-VA settings included having insurance (71.0%); greater convenience of non-VA care (66.9%); lack of knowledge of VA eligibility and services (48.5%); and perceived better non-VA quality (34.5%). After adjustment for sociodemographics, health characteristics, and VA priority group, knowledge deficits about VA eligibility and services and perceived worse VA care quality predicted outside health care use. VA users were less likely than non-VA users to have after-hours access to nonemergency care, but more likely to receive both general and gender-related care from the same clinic or provider, to use a WHC for gender-related care, and to consider WHC availability very important. CONCLUSIONS: Lack of information about VA, perceptions of VA quality, and inconvenience of VA care, are deterrents to VA use for many women veterans. VA WHCs may foster VA use. Educational campaigns are needed to fill the knowledge gap regarding women veterans’ VA eligibility and advances in VA quality of care, while VA managers consider solutions to after-hours access barriers. The author have no conflict of interest to declare. This study was funded by the Department of Veterans Affairs, Health Services Research and Development Service (#GEN-00-082). Dr. Washington is supported by an Advanced Research Career Development Award from the Veterans Affairs Health Services Research and Development Service (#RCD-00-017). The authors gratefully acknowledge Mark Canning for overall project management, Barbara Sasso for assistance with survey development, Martin Lee, PhD, for statistical assistance, and the site principal investigators Leslie Satz, MSN, ANP, Stuart Gilman, MD, MPH, Nancy McNulty, MSN, ANP, and Denise Bartlett-Chekal, MSN, FNP. We also thank James Strike and Rick Paulson of the VA Austin Automation Center and Patricia Murphy of the VA Information Resource Center (VIReC) for assistance with sample development, and California Survey Research Services Inc. for survey fieldwork. The views expressed within are solely those of the authors, and do not necessarily represent the views of the Department of Veterans Affairs.     

Fatal Pulmonary Artery Embolism in a Sickle Cell Patient: Case Report and Literature Review

This article reports a rare case of fatal saddle embolism to the pulmonary artery presenting as an Acute Chest Syndrome (ACS) in a Sickle Cell patient. We present a review of the etiology, pathophysiology, clinical manifestation and management of ACS. Clinicians should be aware of the fact that a sickle cell crisis admission may represent a life-threatening process. Such awareness will help physicians to act promptly and execute proper therapeutic interventions. It is important for clinicians to be expectant of impending clinical deterioration and likewise be aware that ACS can develop in patients hospitalized for other medical or surgical conditions.     

Catheter ablation of ventricular fibrillation storm in patients with infiltrative amyloidosis of the heart

Recent studies have demonstrated that premature ventricular contractions (PVCs) originating from the Purkinje system are responsible for initiation of ventricular fibrillation (VF) in patients with and without structural heart disease. Ablation of the PVCs has been shown to be feasible. We report 2 patients with repetitive VF associated with cardiac amyloidosis. Each episode of ventricular arrhythmia was preceded by monomorphic PVC. The electrical storms were drug resistant. Electrophysiological testing was performed and the sites of earliest activation were localized within the left ventricle in the absence of significant scar tissue. After ablation, PVCs subsided and there were no further VF recurrences.     

Alternative medicine in atrial fibrillation treatment—Yoga,acupuncture, biofeedback and more

The last decade has seen a significant improvement in the management of atrial fibrillation (AF) with the development of newer medications and improvement in catheter ablation techniques. Recurrence of AF remains a significant problem in these patients and medications offer limited supportive role. Complementary and alternative treatment strategies therefore remain a viable option for these AF patients. Several studies have shown improvement in AF symptoms with yoga therapy, acupuncture and biofeedback. There are also several herbal medicine and supplements such as omega-3 fatty acids, antioxidant vitamins, barberry, motherwort, cinchona, Shensongyangxin, hawthorn, Kella and Wenxin Keli that have been evaluated as potential therapeutic options in AF. These studies are however limited by small sample sizes with mixed results. Besides the pharmacological action, metabolism, interactions with other medications and the adverse effects of the herbal medications and supplements remain poorly understood. In spite of the above limitations, complementary therapies remain a promising option in the management of AF and further studies are necessary to validate their safety and efficacy.