Understanding Engagement With Forensic Smartphone Apps: The Service Design Engagement Model.

Justice services have begun to integrate the use of mobile applications into treatment, support, and rehabilitative programs for forensic clients. One such application that been adopted to support forensic clients is "eRecovery": a smartphone application that provides clients recovering from a substance addiction with support for managing relapse. In this article, we report on evaluation findings from a trial of eRecovery in an Australian Community Justice Centre, and reflect on several issues relating to fostering and sustaining client engagement with similar applications within forensic and justice settings. We propose the Service Design Engagement Model to organize, visualize, and describe the stages and factors important to adoption, appropriation, and on-going routine use of the software by forensic clients. The model recognizes the role of contextual and environmental factors in supporting users through the early stages of engagement, and the importance of user agency in longer-term engagement with therapeutic apps.

Primary Crime Prevention Apps: A Typology and Scoping Review.

In the last decade, an array of smartphone apps have been designed to prevent crime, violence, and abuse. The evidence base of these apps has, however, yet to analyzed systematically. To rectify this, the aims of this review were (1) to establish the extent, range, and nature of research into smartphone apps with a primary crime prevention function; (2) to locate gaps in the primary crime prevention app literature; and (3) to develop a typology of primary crime prevention apps. Employing a scoping review methodology and following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies were identified via Web of Science, EBSCOhost, and Google Scholar. We included English-language research published between 2008 and 2020 that examined smartphone applications designed explicitly for primary crime prevention. Sixty-one publications met our criteria for review, out of an initial sample of 151 identified. Our review identified six types of crime prevention app examined in these publications: self-surveillance apps, decision aid apps, child-tracking apps, educational apps, crime-mapping/alert apps, and crime reporting apps. The findings of our review indicate that most of these forms of primary crime prevention apps have yet to be rigorously evaluated and many are not evidence-based in their design. Consequently, our review indicates that recent enthusiasm over primary crime prevention apps is not supported by an adequate evidence base.

Citalopram, QTc interval prolongation, and torsade de pointes. How should we apply the recent FDA ruling?

Recently, both the manufacturer of citalopram and the US Food and Drug Administration have warned health care providers and patients about new information implicating drug-induced QTc interval prolongation and torsade de pointes when using citalopram in doses >40 mg/day. This warning is not placed in the context of either benefits or risks in real-world clinical practice, leaving clinicians with an untenable choice between depriving patients of high-dose citalopram or malpractice litigation. We reviewed the literature and found no cases of citalopram-induced sudden cardiac death among patients taking up to 60 mg/day of citalopram and free of risk factors for QTc interval prolongation and torsade de pointes. Because psychotropic drug-induced sudden cardiac death is an outlier in the absence of identified risk factors for QTc interval prolongation and torsade de pointes, we do not believe current Phase 3 and Phase 4 studies provide sufficient information to limit current prescribing practices for citalopram (20 mg to 60 mg/day). We urge drug manufacturers and regulatory agencies to periodically publish full case reports of psychotropic drug-induced QTc interval prolongation, torsade de pointes, and sudden cardiac death so that clinicians and investigators may better understand the clinical implications of prescribing such drugs as citalopram.

Histopathologic characterization of chronic radiofrequency ablation lesions for pulmonary vein isolation.

OBJECTIVES: This study describes the histopathologic and electrophysiological findings in patients with recurrence of atrial fibrillation (AF) after pulmonary vein (PV) isolation who underwent a subsequent surgical maze procedure. BACKGROUND: The recovery of PV conduction is commonly responsible for recurrence of AF after catheter-based PV isolation. METHODS: Twelve patients with recurrent AF after acutely successful catheter-based antral PV isolation underwent a surgical maze procedure. Full-thickness surgical biopsy specimens were obtained from the PV antrum in areas of visible endocardial scar. Before biopsy, intraoperative epicardial electrophysiological recordings were taken from each PV using a circular mapping catheter. RESULTS: Twenty-two PVs were biopsied from the 12 patients 8 ± 11 months after ablation. Eleven of the 22 specimens (50%) revealed transmural scar, and 11 (50%) showed viable myocardium with or without scar. Each biopsy specimen demonstrated evidence of injury, most commonly endocardial thickening (n = 21 [95%]) and fibrous scar (n = 18 [82%]). Seven of the 22 specimens (32%) showed conduction block at surgery. Transmural scar was more likely to be seen in the biopsy specimens from the PVs with conduction block than in specimens from the PVs showing reconnection. However, viable myocardium alone or mixed with scar was seen in 2 specimens from PVs with conduction block. CONCLUSIONS: PVs showing electrical reconnection after catheter-based antral ablation frequently reveal anatomic gaps or nontransmural lesions at the sites of catheter ablation. Nontransmural lesions are noted in some PVs with persistent conduction block, suggesting that lesion geometry may influence PV conduction. The histological findings show that nontransmural ablation can produce a dynamic cellular substrate with features of reversible injury. Delayed recovery from injury may explain late recurrences of AF after PV isolation.

Detection of a Riata™ insulation failure by the Medtronic Lead Integrity Alert™.

We describe a case of insulation failure in a Riata implantable cardioverter defibrillator lead [St Jude Medical (SJM), St Paul, MN, USA] detected by the Lead Integrity Alert (LIA)™, without impedance changes. The Medtronic LIA may permit early detection of Riata lead failure.

Head-to-head comparison of arrhythmia discrimination performance of subcutaneous and transvenous ICD arrhythmia detection algorithms: the START study.

BACKGROUND: The development of a totally subcutaneous implantable defibrillator (S-ICD) system requires a new approach for arrhythmia detection. To evaluate arrhythmia discrimination of one such system, the Subcutaneous versus Transvenous Arrhythmia Recognition Testing (START) study was designed as a prospective, multicenter trial comparing simulated sensing performances of the S-ICD system with single- (SC-TV) and dual-chamber transvenous (DC-TV) implantable cardioverter-defibrillator (ICD) systems. METHODS: At ICD implantation, induced ventricular and atrial arrhythmias were recorded simultaneously in transvenous (right ventricular [RV] → superior vena cava [SVC]+ Coil) and cutaneous electrode configurations. Recorded signals of ventricular (n = 46) and atrial arrhythmias (n = 50) with ventricular rates >170 bpm from 64 patients were used to compare detection performance of the S-ICD system with TV-ICD systems from 3 manufacturers. Appropriate detection of ventricular tachyarrhythmias was assessed with devices programmed in single-zone (rate ≥ 170 bpm) and dual-zone configurations (ventricular fibrillation ≥ 240 bpm; ventricular tachycardia ≥ 170 bpm). S-ICD specificity performance for supraventricular arrhythmias was compared to single- and dual-chamber devices in a dual-zone configuration. RESULTS: Appropriate detection of ventricular tachyarrhythmias for subcutaneous and TV devices in single- and dual-zone configurations was 100% and >99%, respectively. Specificity for supraventricular arrhythmias was significantly better for the S-ICD system compared to 2 of 3 TV systems, as well as the composite of TV devices (98.0%[S-ICD] vs 76.7%[SC-TV range: 64.0-92.0%] vs 68.0%[DC-TV range: 32.7-89.8%; P < 0.001]). CONCLUSION: Appropriate ventricular arrhythmia detection is excellent for all ICD systems evaluated; however, specificity of supraventricular arrhythmia discrimination by the S-ICD system is better than discrimination by 2 of 3 TV systems.

Disparity in left ventricular stimulation among different pacing configurations in cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) demands high energy utilization due to continuous biventricular pacing. Current technology allows 6 pacing configurations for a bipolar left ventricular (LV) lead. Understanding the energy requirements for each configuration will allow optimization of pacing output. METHODS AND RESULTS: Pacing impedance, LV voltage threshold at 1.5 ms (rheobase) and 0.4 ms and chronaxie were obtained in 6 LV configurations in 49 consecutive patients undergoing CRT implantation or replacement. Strength-duration curves were derived using the Lapicque formula. Pacing impedances and voltage thresholds at 1.5 and 0.4 ms, calculated minimum threshold energy at chronaxie, current drain, energy thresholds at 0.4 ms, and strength-duration curves were statistically different between LV configurations (P<0.05). The lowest threshold energy requirements were found in Tip→right ventricular (RV) coil and Tip→Can configuration. Energy strength-duration curves involving the ring as the cathode (Ring→RV, Ring→Can, and Ring→Tip) had the highest LV thresholds. The pacing configuration with the lowest energy threshold correlated 89% of the time with the lowest voltage threshold at 0.4 ms. The probability to reach LV thresholds <1.5 V at 0.4 ms was increased from 51% with 2 LV configurations to 67% with 6 LV configurations. CONCLUSIONS: Pacing impedance, LV thresholds, minimum threshold energy at chronaxie, current drain, voltage, and energy strength-duration curves were statistically different between LV pacing configurations. LV pacing configuration with the lowest voltage threshold does not always reflects the lowest energy threshold, particularly in the presence of a low impedance configuration. The availability of 6 LV configurations increases the probability of optimizing LV pacing output.

Left ventricular systolic dysfunction induced by ventricular ectopy: a novel model for premature ventricular contraction-induced cardiomyopathy.

BACKGROUND: Premature ventricular contractions (PVCs) commonly coexist with cardiomyopathy. Recently, PVCs have been identified as a possible cause of cardiomyopathy. We developed a PVC-induced cardiomyopathy animal model using a novel premature pacing algorithm to assess timeframe and reversibility of this cardiomyopathy and examine the associated histopathologic abnormalities. METHODS AND RESULTS: Thirteen mongrel dogs were implanted with a specially programmed pacemaker capable of simulating ventricular extrasystoles. Animals were randomly assigned to either 12 weeks of bigeminal PVCs (n = 7) or no PVCs (control, n = 6). Continuous 24-hour Holter monitoring corroborated ventricular bigeminy in the PVC group (PVC, 49.8% versus control, < 0.01%; P<0.0001). After 12 weeks, only the PVC group had cardiomyopathy, with a significant reduction in left ventricular ejection fraction (PVC, 39.7 ± 5.4% versus control, 60.7 ± 3.8%; P < 0.0001) and an increase in left ventricular end-systolic dimension (PVC, 33.3 ± 3.5 mm versus control, 23.7 ± 3.6 mm; P < 0.001). Ventricular effective refractory period showed a trend to prolong in the PVC group. PVC-induced cardiomyopathy was resolved within 2 to 4 weeks after discontinuation of PVCs. No inflammation, fibrosis, or changes in apoptosis and mitochondrial oxidative phosphorylation were observed with PVC-induced cardiomyopathy. CONCLUSIONS: This novel PVC animal model demonstrates that frequent PVCs alone can induce a reversible form of cardiomyopathy in otherwise structurally normal hearts. PVC-induced cardiomyopathy lacks gross histopathologic and mitochondrial abnormalities seen in other canine models of cardiomyopathy.

An alternative technique of implanting a nontransvenous implantable cardioverter-defibrillator system in adults with no or limited venous access to the heart.

BACKGROUND: In some patients at high risk for sudden cardiac death, a transvenous implantable cardioverter-defibrillator (ICD) cannot be implanted owing to limited vascular access. These patients can benefit from a nontransvenous defibrillation system consisting of a rate-sensing lead attached to the epicardium and a subcutaneous (SQ) array. OBJECTIVE: We examine the feasibility, safety, and clinical circumstances requiring implant of nontransvenous defibrillation system in adults. METHODS: Eight patients received an ICD system composed of an SQ array and either a chronic endocardial rate/sense lead (n = 5) or a new epicardial rate/sense lead (n = 3) for primary (n = 2) or secondary (n = 6) prevention. The obstacles to transvenous ICD implantation included recurrent endovascular lead infections (n = 1), congenital heart disease (n = 4), and superior vena cava occlusion (n = 3). The array was tunneled posteriorly, and the epicardial rate-sensing leads were implanted by left lateral minithoractomy. Four patients also required left ventricular pacing. RESULTS: Successful defibrillation was obtained in all patients at 29 ± 2.6 J. There were no major cardiovascular complications. Over a mean follow-up of 545 ± 204 days there was one appropriate and no inappropriate shocks. None of the patients required system revision. There were no significant changes in impedance, pacing threshold, or ventricular sensing observed with the epicardial leads and no change in high-voltage impedance. CONCLUSIONS: The nontransvenous defibrillation system described is an effective technique in an adult population with acceptable pacing and defibrillation threshold.

Long-term fish oil supplementation induces cardiac electrical remodeling by changing channel protein expression in the rabbit model.

Clinical trials and epidemiological studies have suggested that dietary fish oil (FO) supplementation can provide an anti-arrhythmic benefit in some patient populations. The underlying mechanisms are not entirely clear. We wanted to understand how FO supplementation (for 4 weeks) affected the action potential configuration/duration of ventricular myocytes, and the ionic mechanism(s)/molecular basis for these effects. The experiments were conducted on adult rabbits, a widely used animal model for cardiac electrophysiology and pathophysiology. We used gas chromatography-mass spectroscopy to confirm that FO feeding produced a marked increase in the content of n-3 polyunsaturated fatty acids in the phospholipids of rabbit hearts. Left ventricular myocytes were used in current and voltage clamp experiments to monitor action potentials and ionic currents, respectively. Action potentials of myocytes from FO-fed rabbits exhibited much more positive plateau voltages and prolonged durations. These changes could be explained by an increase in the L-type Ca current (I(CaL)) and a decrease in the transient outward current (I(to)) in these myocytes. FO feeding did not change the delayed rectifier or inward rectifier current. Immunoblot experiments showed that the FO-feeding induced changes in I(CaL) and I(to) were associated with corresponding changes in the protein levels of major pore-forming subunits of these channels: increase in Cav1.2 and decrease in Kv4.2 and Kv1.4. There was no change in other channel subunits (Cav1.1, Kv4.3, KChIP2, and ERG1). We conclude that long-term fish oil supplementation can impact on cardiac electrical activity at least partially by changing channel subunit expression in cardiac myocytes.

An unusual source of electromagnetic interference: a device-device interaction.

INTRODUCTION: Implantable cardioverter-defibrillators (ICDs) are susceptible to oversensing of extracardiac signals, also known as electromagnetic interference (EMI). We report a case of an unusual source of electrical interference of only the high voltage (HV) impedance measurement in the Teligen ICD (Boston Scientific, St. Paul, MN, USA) caused by electrical interference from an electrosurgical generator with an electrocautery patch located in close proximity to the ICD pulse generator. METHOD AND RESULTS: A patient underwent an uneventful implant of a Boston Scientific Teligen 100 ICD. Once the device was inserted in a pocket, interrogation of the device repeatedly demonstrated HV electrode impedance measurements between <20 and 40 Omega and noise only on the HV electrode. A new lead and generator were implanted without a change in the interrogation results. The erroneous measurements of HV impedance were caused by a combination of the close proximity of the electrocautery patch to the ICD generator. The continuous low-amplitude current emitted by the contact quality monitoring system of the electrosurgical cautery generator interfered with an equally weak current delivered through the lead by the device to measurement HV impedance. The Medtronic Virtuoso (Medtronic Inc., Minneapolis, MN, USA) ICD and the St. Jude Medical Current DR (St. Jude Medical, St. Paul, MN, USA) ICD were not affected by the patch due to greater magnitude of current delivered by the device to measure HV electrode impedance. CONCLUSION: It is important that the operator must be aware of any potential source of EMI, as it may affect the device and require immediate troubleshooting. Failure to recognize this interaction may result in inappropriate and unnecessary pulse generator replacement.

Management of recurrent atrial arrhythmias after minimally invasive surgical pulmonary vein isolation and ganglionic plexi ablation for atrial fibrillation.

BACKGROUND: Minimally invasive thoracoscopic procedures have evolved for surgical treatment of atrial fibrillation (AF). The spectrum and management of arrhythmias after minimally invasive epicardial radiofrequency ablation of the pulmonary vein (PV) antrum have not been well studied. OBJECTIVE: The aim of this study was to describe the spectrum and treatment of recurrent atrial tachyarrhythmias (AT) after minimally invasive AF surgery. METHODS: Fifty patients underwent bipolar radiofrequency (RF) ablation of the PV antrum, parasympathetic ganglionated plexi, and ligament of Marshall. Twenty patients (40%) had recurrent AT, and 13 underwent electrophysiology study 100 to 948 days postoperatively (mean 383 +/- 234). RESULTS: Fourteen arrhythmias were identified in 13 patients 90 to 666 days (mean 214 +/- 162) after AF surgery. The most common arrhythmias were AF (N = 8) and atrial flutter (N = 3). Of 44 PVs examined, 22 (50%) had reconnected. Seven of 8 patients with recurrent AF had either 2 or 3 veins reconnected, and 6 of 8 had reconnection of the left superior PV. On average, 25.6% of each PV reconnected and showed conduction delay between the left atrium and PV. Two of 4 postoperative atrial flutters were due to isthmus-dependent re-entry. After catheter ablation, 2 patients had symptomatic recurrence of AT. CONCLUSION: Recurrent AT occurs in up to 40% of patients after minimally invasive thoracoscopic AF surgery during a minimal follow-up of 12 months. PV reconnection accounts for most recurrences. Postoperative AT appears amenable to catheter ablation, often in conjunction with medical therapy, with high intermediate-term success.

Efficacy of a cooled bipolar epicardial radiofrequency ablation probe for creating transmural myocardial lesions.

OBJECTIVE: Creation of transmural myocardial lesions with epicardial surgical devices to treat atrial fibrillation is difficult. A new cooled bipolar radiofrequency ablation probe was used to create transmural myocardial lesions under controlled conditions. METHODS: The Coolrail (AtriCure, Inc, West Chester, Ohio) is a handheld probe with 2 parallel 30-mm long radiofrequency conductors. Conductors are cooled by water irrigation. Lesions were delivered to epicardial surface of isolated bovine myocardium sliced 3- to 8-mm thick, with blood flow beneath tissue at 0 or 0.4 m/s. Contact pressure between probe and tissue was either 450 g or 900 g. Tissue temperatures were measured. Tissue was sectioned every 5 mm along lesion long axis to determine lesion dimensions. RESULTS: For 80 experiments with 450-g contact pressure, epicardial lesion length was 31.3 mm (interquartile range, 30.1-32.8 mm); endocardial lesion length was 14.1 mm (interquartile range, 0.0-22.6 mm). Average lesion depth was 4.2 +/- 0.74 mm. Temperature at probe interface was 81 degrees C +/- 21 degrees C; that at blood pool interface was 53 degrees C +/- 12 degrees C. Lesions were always transmural when tissue thickness was 4.0 mm or less. Endocardial blood flow did not influence lesion depth. With 900-g contact pressure, increased depth was always transmural at 4.8-mm tissue thickness or less. CONCLUSIONS: This irrigated bipolar radiofrequency probe consistently produced transmural lesions in tissue 4 mm or thinner under controlled conditions in vitro. Lesion depth was increased by greater pressure on probe and not affected by blood flow. Endocardial lesions were smaller than epicardial dimensions.

Proarrhythmic risk with antipsychotic and antidepressant drugs: implications in the elderly.

The quinidine-like effects of some antidepressant drugs (particularly tricyclic antidepressants) and many antipsychotic drugs (particularly the phenothiazines) confound treatment of psychosis and depression in patients with major mental illness. This is especially true among elderly patients with existing risk factors for corrected QT (QTc) interval prolongation. We used PubMed, previously reported review articles and the extensive personal files of the authors to identify cases of subjects aged>or=60 years who developed QTc interval prolongation, polymorphic ventricular tachycardia (PVT)/torsade de pointes (TdP) and/or sudden cardiac death while taking antipsychotic or antidepressant drugs or a combination of these medications. We identified 37 patients who had taken, in total, 46 antipsychotic or antidepressant drugs. Our most striking finding was that almost four-fifths of our cases involved women. When the 14 critically ill subjects receiving haloperidol intravenously were excluded, 91.3% of our subjects were women. Almost three-quarters of our study subjects had cardiovascular disease. Intravenous administration of haloperidol in the critically ill and profoundly agitated elderly warrants particular comment. Of the 14 subjects in this category identified, six were men and eight were women. In 13 cases, the drug dose far exceeded the 2 mg necessary to produce an antipsychotic effect. These clinicians were using an agent to achieve sedation that usually requires very high doses in the critically ill and profoundly agitated elderly to achieve this effect. Inclusion criteria for our literature review required antipsychotic and/or antidepressant drug-induced QTc interval prolongation. Even so, our finding that 31 of our 37 subjects developed PVT is sobering. However, the reader should not conclude that drug-induced QTc interval prolongation is highly predictive of PVT or its TdP subtype. All of our study subjects had at least two risk factors for TdP, with age and sex being the most common. We included the rare case of a patient with congenital long QT syndrome who developed further lengthening of the QTc interval and TdP when prescribed an antidepressant drug well known to produce QTc interval prolongation. We conclude with recommendations for clinicians not expert in the specialty of cardiology to deal with the many questions raised in this review. Specifically, such clinicians treating elderly patients with antipsychotic and antidepressant drugs that may prolong the QTc interval should aggressively obtain a baseline ECG for elderly female patients with additional risk factors such as personal or family history of pre-syncope or syncope, electrolyte disturbances or cardiovascular disease. Elderly male patients are also subject to QTc interval prolongation when such risk factors are present. It is important that the clinicians themselves inspect ECGs. If the QT interval is more than half the RR interval, QTc interval prolongation is likely to be present. In such cases, a cardiology colleague interested in QTc interval issues and TdP should be asked to review the ECG. Finally, nothing in our recommendations replaces meticulous attention to US FDA guidelines in the package insert of each drug.