CHA(2)DS(2)-VASc versus CHADS(2) for stroke risk assessment in low-risk patients with atrial fibrillation: a pilot study from a single center of the NCDR-PINNACLE registry.

The CHADS(2) score is widely used to assess the risk of stroke in patients with atrial fibrillation (AF). Patients with score of 0 and 1 are considered 'low risk' and are often treated with aspirin. In a Danish Study, the CHA(2)DS(2)--VASc score was shown to identify low and high-risk subgroups among patients with CHADS(2) score of 0 and 1, with annual risk ranging from 0.84 to 8.18%. This study seeks to assess whether using CHA(2)DS(2)--VASc score will identify high-risk subset of patients with low CHADS(2) scores in an American population. This pilot study examined data from our cardiology fellowship ambulatory clinics from January 2009 to May 2012 using the NCDR-PINNACLE registry. Each cardiology fellow entered patients' data using on-line software developed by the American College of Cardiology. Among 2,048 patients followed at our clinics, 478 had AF. Of those, 161 patients had CHADS(2) score of 0 (44 patients) or 1 (117 patients). Calculating the CHA(2)DS(2)--VASc score in these patients, 12 (7.4%) had score of 0, 50 (31.1%) had score of 1, 66(41%) had score of 2, 31 (19.3%) had score of 3 and 2 (1.2%) had score of 4. Using original CHADS(2) recommendation, warfarin would not be strongly recommended in any of these patients. Utilizing the CHA(2)DS(2)--VASc score, 61.5% of the 161 patients would have a score of 2 or more signifying increased risk where anticoagulation may be indicated. Compared to CHADS(2), CHA(2)DS(2)--VASc may more precisely predict the risk of stroke and anticoagulation strategy in low-risk patients with non-valvular AF.

Laser in infra-popliteal and popliteal stenosis (LIPS): retrospective review of laser-assisted balloon angioplasty versus balloon angioplasty alone for below knee peripheral arterial disease.

Despite the use of laser technology over the last decade, there are limited data to show its procedural and clinical success in infra-popliteal disease. We hypothesized that laser-assisted balloon angioplasty (LABA) is at least similar or better in procedural and peri-procedural outcomes compared to balloon angioplasty (BA) alone, despite adverse lesion characteristics prior to intervention. Retrospective chart and angiogram review of consecutive critical limb ischemia (CLI) patients who underwent endovascular revascularization in the popliteal or infra-popliteal vessels between 2007 and 2012 with LABA or BA alone. Data from 731 patients revealed that baseline demographics were similar in the LABA (n = 398) and BA group (n = 333) with minor exceptions. More patients in the LABA group had TASC-D lesions (92.5 vs. 66.7 %; P < 0.0001) and chronic total occlusions (CTOs) in both vessel 1 (86.4 vs. 49.5 %; P < 0.0001) and vessel 2 (78.6 vs. 47.8 %; P < 0.0001). Multivariate analysis performed using logistic regression after adjusting for confounding factors showed use of LABA was associated with a 7 times greater likelihood of achieving <50 % residual disease compared to BA alone (OR 7.59, P < 0.0001), and a 5 times greater likelihood of improvement in the infra-popliteal lesion severity score than balloon angioplasty alone (OR 4.77, p < 0.0001). LABA is significantly better at achieving angiographic success and improving lesion severity score in spite of adverse lesion characteristics (more TASC-D lesions and CTOs) compared with BA alone. Our findings suggest that the use of LABA is an endovascular approach that is at least as effective and safe or better compared to BA for the treatment of CLI from complex popliteal and infra-popliteal vascular disease.

Complexation of chitosan with surfactant like ionic liquids: molecular interactions and preparation of chitosan nanoparticles.

Interactions and behavior of chitosan (Ch) with surface active ionic liquids (ILs)- 1-butyl-3-methylimidazolium octylsulfate, [C4mim][C8OSO3] or 3-methyl-1-octylimidazolium chloride, [C8mim][Cl]-have been probed at the air solution interface and in the bulk in aqueous media at pH 3.0 using a multi-technique approach, viz. tensiometry, conductometry, turbidimetry, dynamic light scattering (DLS), and atomic force microscopy (AFM). At the interface, a strong complexation is observed in Ch-[C4mim][C8OSO3] system. Bulk [C4mim][C8OSO3] interacts with Ch to form Ch-[C4mim][C8OSO3] complexes which precipitate out at higher IL concentrations, whereas comparatively weaker Ch-[C8mim][Cl] complexes remain solubilized in the solution. DLS measurements showed that the Ch chains contract before the cmc and expands after the cmc upon interaction with both the ILs. Interaction of ILs with Ch resulted in facile preparation of uniformly distributed Ch nanoparticles with good sphericity and control which have been verified using DLS, SEM, AFM, and fluorescence microscopy. The present study provides an understanding of forces governing the complexation behavior of Ch with surface active ILs and their efficacy to produce Ch nanoparticles.

First steps: exploring use of a prospective, office-based registry as the foundation for quality improvement in cardiology training.

BACKGROUND: Teaching practice-based learning and improvement and systems-based practice are challenging. Cardiology fellows at St John Hospital & Medical Center participate in a national registry of outpatient cardiology care. OBJECTIVE: We assessed the use of the registry, hypothesizing that it could serve as an effective foundation for studying ambulatory care, identifying gaps in care, and planning interventions to advance competence in practice-based learning and improvement and systems-based practice. METHODS: Starting in 2009, trainees prospectively entered data for ambulatory cardiac patients into the PINNACLE Registry database where compliance with 28 performance measures was calculated and reported quarterly. Fellows met with the program director individually and in groups to identify performance gaps and to develop and implement plans for quality improvement. Cardiology fellows were surveyed annually to assess this process. RESULTS: Through March 2012, the fellows had completed 2400 patient visits. Participation was feasible because it was cost neutral, with data form completion averaging 5 minutes. It was acceptable, with most fellows describing positive effects on practice-based learning and improvement without significant detriment to work flow. Performance achievement for drug therapies ranged from 69% (77 of 111) of the patients with atrial fibrillation receiving anticoagulation to 99% (486 of 489) of patients with coronary disease receiving lipid-lowering therapy. Gaps in system performance included low levels for diabetes screening (5%; 20 of 422) and lipid monitoring (10%; 58 of 573). Initial quality improvement projects addressed practice gaps with straightforward solutions. Improving system performance was more challenging. CONCLUSIONS: Using a registry in cardiology trainees' outpatient practice is feasible, acceptable, and valuable. It allows for planning and studying the effects of quality improvement projects.

Ionic liquids induced structural changes of bovine serum albumin in aqueous media: a detailed physicochemical and spectroscopic study.

Structural changes of a globular protein, bovine serum albumin (BSA), as a consequence of interaction with the surface active ionic liquids (ILs)-3-methyl-1-octylimidazolium chloride, [C(8)mim][Cl], and 1-butyl-3-methylimidazolium octylsulfate, [C(4)mim][C(8)OSO(3)]-have been investigated using various physicochemical and spectroscopic techniques such as tensiometry, conductometry, steady-state fluorescence, far-UV circular dichroism spectroscopy (CD), and dynamic light scattering (DLS). The interactional behavior of ILs (monomers and self-assembled structures) toward BSA in different IL concentration regimes at the air/solution interface as well as in the bulk is investigated and discussed depending upon the nature of ions of ILs. CD combined with the steady state fluorescence spectroscopy provided valuable insights into the unfolding of BSA as a consequence of IL binding. The complementary results obtained from the multitechnique approach proved very useful in drawing out the mechanism of interaction between ILs and BSA in different IL concentration regimes.

Effect of ethylene glycol and its derivatives on the aggregation behavior of an ionic liquid 1-butyl-3-methyl imidazolium octylsulfate in aqueous medium.

The effect of ethylene glycol (EG) and its derivatives, ethylene glycol monomethyl ether (EGMME), or ethylene glycol dimethyl ether (EGDME), on the aggregation behavior of a surfactant-like ionic liquid (IL), 1-butyl-3-methyl imidazolium octylsulfate, [C(4)mim][C(8)OSO(3)], in aqueous solutions is investigated using conductivity, surface tension, fluorescence, (1)H NMR, and dynamic light scattering (DLS) measurements. Thermodynamic parameters such as Gibbs free energy (ΔG(m)°), standard enthalpy (ΔH(m)°), and standard entropy (ΔS(m)°) of aggregation are determined from the temperature dependence of conductivity. The interfacial properties of IL at the air/water interface in various mixed solvents are evaluated from surface tension measurements. Information about the local microenvironment and size of the aggregates is obtained from steady-state fluorescence using pyrene as a polarity probe and DLS measurements, respectively. (1)H NMR data has been employed to get detailed insight into the effect of organic additives on the IL aggregate structure and aggregation number. It has been observed that the addition of organic additives to water decreases the spontaneity of aggregation of IL.

Aggregation behavior of amino acid ionic liquid surfactants in aqueous media.

Self-aggregation of amino acid ionic liquid surfactants (AAILSs) in aqueous solution has been investigated through surface tension, conductivity, steady-state fluorescence, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The critical aggregation concentration (cac) of AAILSs obtained from different techniques showed fairly good agreement. Surface tension measurements have been used to derive surface adsorption properties such as adsorption efficiency (pC(20), effectiveness of surface tension reduction (Π(cac)), and minimum surface area per molecule (A(min)) at the air-water interface. Temperature-dependent conductivity measurements have been used to obtain the degree of counterion binding (ß), and the thermodynamic parameters such as standard free energy (ΔG(agg)(0)), enthalpy (ΔH(agg)(0)), and entropy (ΔS(agg)(0)) of aggregation. The aggregation number (N(agg)) for various AAILSs has been derived by using the fluorescence quenching technique. Size of the aggregates has been obtained from DLS and TEM measurements. The aggregation properties of AAILSs have been analyzed as a function of structure of amino acids and compared with those of analogous ionic liquids (ILs) and conventional ionic surfactants. Surface activity of the AAILSs has been found superior to that of analogous ILs and conventional ionic surfactants of the same alkyl chain length.

Tissue removal by ultrasound evaluation (the TRUE study): the Jetstream G2 system post-market peripheral vascular IVUS study.

BACKGROUND: Balloon angioplasty and stenting of infra-inguinal lesions is limited by poor long-term patency rates. Atherectomy decreases plaque burden and provides an alternative means of revascularizing patients with peripheral arterial disease. The Jetstream G2™ (Pathway Medical Technologies, Inc., Kirkland, Washington) is a newer rotational aspiration atherectomy device, uniquely combining rotablation with aspiration capability. We evaluated the debulking properties of this device by analyzing changes in the plaque volume and composition and vessel size using intravascular ultrasound (IVUS) and virtual histology (VH). Freedom from target lesion revascularization (TLR) at 6 and 12 months was also evaluated. METHODS AND RESULTS: Eighteen patients with peripheral arterial disease requiring intervention (severe claudication despite optimal medical treatment or critical limb ischemia) were treated with rotational atherectomy. The mean age was 69.6 ± 11 years, 66.7% were male, and 44.4% had diabetes. The mean total plaque volume decreased by 56.6 mm³ (479.8 ± 172.5 mm³ to 423.2 ± 156.6 mm³; p < 0.0001), which resulted in a mean luminal volume increase of 64.3 mm³ (148.4 ± 84.1 mm³ to 212.7 ± 72.1 mm³; p < 0.0001). This was achieved without significant Dotter effect with either technique, as evidenced by the virtually unchanged vessel volume before and after treatment (628.3 ± 158.5 mm³ and 635.9 ± 169.0 mm³, respectively; p = 0.22). There was a significant reduction in fibrotic and fibro-fatty plaque volume, with no appreciable effect on necrotic core and dense calcium. There were no reported procedure-related complications and the 6- and 12-month TLR rate was 11% (2/18). CONCLUSION: Atherectomy with the Jetstream G2 system results in substantial plaque volume reduction by removing fibrotic and fibro-fatty plaque. This resulted in substantial luminal volume expansion without concomitant vessel expansion. There were no major procedure-related complications, along with a relatively low 6- and 12-month rate of TLR. Future studies involving a larger number of patients are warranted to examine the potential clinical benefits of this promising technology.

Aqueous-mixed ionic liquid system: phase transitions and synthesis of gold nanocrystals.

Micelle-vesicle-micelle (MVM) transitions are observed in the aqueous-mixed ionic liquid (1-butyl-3-methylimidazolium octyl sulfate and 3-methyl-1-octylimidazolium chloride) system. The surface activity of mixed ILs, phase behavior, and solution structures in the system have been thoroughly characterized using conductometry, tensiometry, fluorimetry, dynamic light scattering (DLS), viscometry, turbidity, atomic force microscopy (AFM), transmission electron microscopy (TEM), and (1)H NMR techniques. Synergetic interactions between the two ILs in monolayers at the air/water interface and in micelles/vesicles have been determined using the regular solution approach, and the origins of spontaneous vesicle formation in this novel system are discussed. Using a photoreduction method, the formation of stable gold nanoparticles (GNPs) and microscale nanosheets of different shapes and sizes in the micellar and vesicle solutions has been reported. The studies show the potential of a mixed IL system in constructing stable micelles/supramolecular assemblies, such as bilayer vesicles, which are effective in the preparation of the desired nanomaterials.

Increased left ventricular mass and decreased left ventricular systolic function have independent pathways to ventricular arrhythmogenesis in coronary artery disease.

BACKGROUND: Following myocardial infarction, individual patients can have wide variations in the extent of left ventricular systolic dysfunction (LVSD) and increased left ventricular (LV) mass. Both affect the risk for sudden cardiac death, but only LV ejection fraction is used for risk prediction. OBJECTIVE: The purpose of this study was to evaluate the independent as well as the additive contributions of increased LV mass and decreased LV ejection fraction to sudden cardiac death in the general population. METHODS: In the ongoing Oregon Sudden Unexpected Death Study, we studied consecutive SCD cases (n = 191) and coronary artery disease controls (n = 203) from the Portland, Oregon, metropolitan area (population approximately 1,000,000; 2002-2008). Comparisons of echocardiographic LV mass obtained prior and unrelated to sudden cardiac death (SCD) were conducted, and a logistic regression model was used to evaluate the relationship between SCD, severe LVSD, LV mass, and other relevant clinical variables. RESULTS: In a multivariate model, both severe LVSD and left ventricular hypertrophy (LVH) were associated with increased SCD risk (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.1-3.2 for severe LVSD; OR 1.8, 95% CI 1.1-2.9 for LVH). In patients with coexisting severe LVSD and LVH, risk of SCD was additive (OR 3.5, 95% CI 1.7-7.2). In the same model, increased age, atrial fibrillation/flutter, elevated creatinine, and diabetes independently increased risk, and use of angiotensin receptor blockers attenuated risk. CONCLUSION: Reduced LV ejection fraction and increased LV mass had independent and additive effects on risk of sudden death. Despite the significant overlap between the two conditions, these findings point toward the existence of independent mechanistic pathways for ventricular arrhythmias that occur due to LVSD and LVH.

Polarity behaviour and specific interactions of imidazolium-based ionic liquids in ethylene glycol.

The molecular interactions of the ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate [C(4)mim][BF(4) ], 3-methyl-1-octylimidazolium tetrafluoroborate [C(8)mim][BF(4)] and 1-butyl-3-methylimidazolium octylsulfate [C(4)mim][C(8)OSO(3)] are investigated in ethylene glycol (EG) over the whole mole fraction range using fluorescence (steady-state and time-resolved), Fourier transform infrared and nuclear magnetic resonance (NMR) spectroscopy. The cybotactic region surrounding the pyrene fluorescent probe exhibits peculiar characteristics for different ILs in the EG-rich region. The extent of solute-solvent interactions is assessed by determining the deviations of experimentally observed vibronic band intensity ratios of peak 1 to peak 3 of pyrene fluorescence (I(1)/I(3)) from a composite I(1)/I(3) value obtained using a preferential solvation model. A distinct vibrational frequency shift for various stretching modes of EG (O−H) or ILs (C−H of ring protons, B−F and S=O of anions) indicates specific interactional preferences of EG toward the IL protons/anion. Splitting of the O−H vibration band of EG at 3000-3700 cm(-1) into three separate bands, and analysis of the changes in location and area of these bands as a function of concentration enable precise determination of the effect of ILs on hydrogen bridges of EG. NMR chemical shifts and their deviations from ideality show multiple hydrogen-bonding interactions of varying strengths between unlike molecules in the mixtures. A comparison of spectroscopic results with thermodynamic properties shows that the mixing microscopic behaviour of the investigated systems is completely different from the macroscopic behaviour, which is primarily governed by the difference in shape, size and nature of the molecules.

Chronic kidney disease and mortality in implantable cardioverter-defibrillator recipients.

Incidence of sudden cardiac death (SCD) in end-stage renal disease (ESRD) remains high. Limited data is available about whether implantable cardioverter-defibrillators (ICDs) can prevent arrhythmic death in patients with chronic kidney disease (CKD). The purpose of this retrospective study was to determine the impact of CKD on all-cause and sudden cardiac death in ICD recipients. We evaluated 441 consecutive patients who underwent ICD implantation at our center between 1994 and 2002. We found that mortality rate was higher in patients with eGFR <60 mL/min and those with ESRD on hemodialysis (43%, n = 69/162 and 54%, n = 12/22, resp.) than in patients with eGFR >/=60 mL/min (23%, n = 58/257; P < .0005). The SCD rate was also higher in the patients with ESRD (50%) than in CKD patients not on dialysis (10.2%; P < .0005). Mortality rate for single-chamber ICDs was 56.8% in comparison with dual-chamber ICDs (38.1%) and for biventricular ICDs (5.0%) (P < .0005).

Micellar transitions in the aqueous solutions of a surfactant-like ionic liquid: 1-butyl-3-methylimidazolium octylsulfate.

We have observed dual transitions in various physical properties while investigating the surfactant-like behavior of the ionic liquid (IL) 1-butyl-3-methylimidazolium octylsulfate [C(4)mim][C(8)SO(4)] in aqueous media. Interestingly, in conductivity measurements, it was found that the second transition, which is comparatively weak in pure water, can be modulated and tuned to the desired concentration without affecting the first transition by the addition of a suitable electrolyte. Using an array of techniques, such as conductivity, ultrasonics, TEM, cryo-TEM, DLS, (1)H NMR and 2D (1)H-(1)H NOESY, it has been revealed that the first transition corresponds to the anionic aggregation with imidazolium cations adsorbed as counterions, and the second transition corresponds to the restructuring of the initially formed aggregates in a way that the alkyl chain of the imidazolium cation is incorporated towards the micellar core, leading to a unique mixed micelle-type structure in a single IL system.

Interaction of gelatin with room temperature ionic liquids: a detailed physicochemical study.

Interaction of gelatin (G) with room temperature ionic liquids (ILs), 3-methyl-1-octylimidazolium chloride [C(8)mim][Cl] and 1-butyl-3-methylimidazolium octylsulfate [C(4)mim][C(8)OSO(3)], have been investigated through tensiometry, conductivity, steady-state fluorescence, turbidity, and dynamic light scattering (DLS). We have observed that the nature of interactions in G-[C(8)mim][Cl] system are remarkably different as compared to G-[C(4)mim][C(8)OSO(3)] system. At low concentrations, much below the critical micelle concentration (cmc) of IL, the IL monomers are adsorbed at the native G at the interface forming G-IL (monomer) complex, whereas both the monomers and lower IL aggregates are interacted with G in bulk leading to G-IL (aggregate) complex. The increased hydrophobic character of the G-IL complexes is evidenced from pyrene fluorescence. Turbidity measurements showed interestingly distinguished coacervation characteristics in the investigated systems. In case of G-[C(4)mim][C(8)OSO(3)] system, the coacervates dissolve in the free micellar solution whereas G-[C(8)mim][Cl] coacervates remain stable up to very high concentration. DLS provided useful information about the changes in size of gelatin and the nature of interactions between gelatin and ILs. Thermodynamic parameters of micellization with and without gelatin have been derived and compared.

Fulminant giant cell myocarditis and cardiogenic shock: an unusual presentation of malignant thymoma.

Malignant thymoma is rarely associated with giant cell myocarditis. We present a case study that illustrates this association and cardiogenic shock with underlying tamponade. The dramatic presentation of this scenario has not been previously described.

Effect of sodium sulfate on the gelling behavior of agarose and water structure inside gel networks.

Agarose hydrogels which constitute a special class of soft matter are undoubtedly one of the most studied biopolymer gels. However, certain issues such as why the sulfate salts and sulfate content in the agarose molecules reduce the gel strength are still not very clear. The present work provides a detailed analysis of structural changes with respect to coil-helix transition or aggregation of helices in the aqueous agarose solutions and hydrogels that accompanied the systematic addition of sodium sulfate. A combined approach which includes the differential scanning calorimetry and temperature-dependent vacuum-ultraviolet circular dichroism measurements permitted the accurate estimates of the energy changes for coil-helix transition and helix-helix interactions. The hydration process of agarose molecule investigated from differential scanning calorimetry and concentration-dependent ultrasonic measurements indicated the loss of both the freeze bound and nonfreezable water molecules with the increase of sulfate content in the solution. Temperature-dependent fluorescence measurements using pyrene as a probe indicated polarity changes when the gel network is created in waters of different salt concentration. Changes in the hydrogen bonding of the water molecules confined in the gel network have been monitored from the intensity ratios of ice-like and liquid-like -OH stretching band of water Fourier transform infrared (FTIR) spectra. Analysis of the -OH stretching band showed the strengthening of hydrogen bonding of water molecules in the gel which tend to weaken with the subsequent addition of sodium sulfate.

Determinants of prolonged QT interval and their contribution to sudden death risk in coronary artery disease: the Oregon Sudden Unexpected Death Study.

BACKGROUND: In a recent cohort study, prolongation of the corrected QT interval (QTc) was associated with an independent increased risk of sudden cardiac death (SCD). We evaluated determinants of prolonged QTc and the relationship of prolonged QTc to SCD risk among patients with coronary artery disease in the general population. METHODS AND RESULTS: A case-control design was used. Cases were SCD patients with coronary artery disease among a metropolitan area of 1 000 000 residents (2002 to 2006); controls were area residents with coronary artery disease but no history of SCD. All cases were required to have an ECG suitable for QTc analysis before and unrelated to the occurrence of SCD. A total of 373 cases and 309 controls met criteria for analysis. Mean QTc was significantly longer in cases than in controls (450+/-45 versus 433+/-37 ms; P<0.0001). In a multivariate model, gender, diabetes mellitus, and QTc-prolonging drugs were significant determinants of QTc prolongation in controls. In a logistic regression model predicting SCD, diabetes mellitus (odds ratio, 1.97; 95% confidence interval, 1.32 to 2.96) and use of QTc-prolonging drugs (odds ratio, 2.90; 95% confidence interval, 1.92 to 4.37) were significant predictors of SCD among subjects with normal or borderline QTc. However, abnormally prolonged QTc in the absence of diabetes and QT-prolonging medications was the strongest predictor of SCD (odds ratio, 5.53; 95% confidence interval, 3.20 to 9.57). CONCLUSIONS: Diabetes mellitus and QTc-affecting drugs determined QTc prolongation and were predictors of SCD in coronary artery disease. However, idiopathic abnormal QTc prolongation was associated with 5-fold increased odds of SCD. A continued search for novel determinants of QTc prolongation such as genomic factors is likely to enhance risk stratification for SCD in coronary artery disease.

Physical activity as a trigger of sudden cardiac arrest: the Oregon Sudden Unexpected Death Study.

BACKGROUND: Sudden cardiac arrest (SCA) is a significant public health problem and better understanding of triggers could enhance prevention. Vigorous physical activity has been suggested as a prominent trigger but has not been well-evaluated in the general population. We performed a community-based study to analyze the role of physical activity as a potential trigger of SCA. METHODS: Medical records of 1180 subjects who sustained SCA during the ongoing Oregon Sudden Unexpected Death Study (Multnomah County, Oregon, USA; 2002-05) were reviewed. Analysis was limited to first responder and hospital records of patients who experienced witnessed SCA, with information available regarding physical activity immediately prior to SCA. An estimated metabolic equivalent (MET) score was used to classify levels of physical activity. RESULTS: A total of 304 adults met criteria for analysis (mean age 69 years, 67% male). The majority (n=193, 63%) were performing light activities, 51 (17%) subjects were sleeping, 39 (13%) were performing moderate activities, 14 (5%) were performing heavy activities, and 7 (2%) were engaged in sexual activity. Light activities were associated with older age (72 years) and heavy activities with the youngest (51 years, p<0.001). Males were more likely to be involved in heavy activity (93% male) and the sexual activity group was exclusively male (p=0.04). CONCLUSION: Vigorous physical activity was a potential trigger of SCA in a minority (5%). The vast majority (80%) of subjects were asleep or were performing light activities. The traditional view of SCA triggers may have to be re-visited, with renewed focus on factors such as emotional stress and sleep-related disorders.