Cardiac Loop Research Articles

Effect of pharmacological treatment prior to admission on the outcome of older hip fracture patients

PurposeWe aim to relate the pharmacological treatment at admission of hip fracture patients with their prognosis. MethodsWe designed a prospective study including 436 hip fracture patients. We classified all the pharmacological treatment prior to admission of each patient into 25 groups according to their active agent and indications. We followed-up patients for one year for survival, emergency department visits (EDV), and in-hospital re-admissions (RAD). Differential analysis was performed by chi-square test, U-Mann Whitney test, and logistic regression. In all cases, p ≤ 0.05 was considered statistically significant. ResultsAt 30-day follow-up, 14.9% patients noted EDV, 9.2% RAD, and 3.2% dead. Patients taking beta-blockers (p = 0.046), loop diuretics (p = 0.018) or antiparkinsonian (p = 0.009) showed an increased 30-day EDV; patients taking benzodiazepines (p = 0.014), loop diuretics (p = 0.009) or antiparkinsonian (p = 0.009), an increased 30-day RAD. At one-year follow-up, 50.7% patients noted EDV, 30.7% RAD, and 22.7% dead. Patients taking oral antidiabetics (p = 0.006) noted a greater one-year EDV; patients taking major opioids (p = 0.001), benzodiazepines (p = 0.016), cardiac agents (p = 0.046), loop diuretics (p = 0.042), beta-blockers (p = 0.018), oral anticoagulants (p = 0.013) or gastric prophylaxis (p = 0.020), greater RAD; patients taking cardiac agents (p = 0.024), loop diuretics (p = 0.006) or oral anticoagulants (p = 0.015), increased 1-year mortality rate. ConclusionsThe pharmacological treatment noted at admission for hip fracture patients is related to the outcome, in a dose-independent way. The pharmacological treatment could be an additional parameter that could help us to improve the decision-making process and the resource assignation of hip fracture patients. A proper medication review upon admission because of a hip fracture is warranted.

Abstract 14433: High Intensity Exercise Training Safely Increases Cardiorespiratory Fitness in Patients With Hypertrophic Cardiomyopathy

Introduction: Patients with hypertrophic cardiomyopathy (HCM) are excluded from high intensity activities due to perceived fear of sudden cardiac death. Observational data from athletes with HCM suggest that engaging in high intensity exercise (HIE) may be safe and is associated with higher cardiorespiratory fitness. Whether HIE can safely elicit a superior increase in fitness compared to moderate intensity exercise in patients with HCM is unclear. Methods: Nine HCM patients (49 ± 7 years, 3 female) were assessed for maximal oxygen uptake (VO 2 max, Douglas Bag method), cardiac output (Q c , acetylene rebreathing), and peripheral oxygen extraction (av-O 2 diff, Fick equation) before randomization and after 5 months of MIE or HIE training. Patients completed 3-4 sessions of MIE each week, while the HIE group also incorporated 1-2 supervised high intensity interval training sessions/week from month 3 onwards. Arrhythmias were monitored via pre-existing implantable cardiac defibrillators or implantable loop recorders placed prior to training. Results: Five months of MIE increased absolute VO 2 max by 3% and relative VO 2 max by 4%, while HIE consistently increased absolute VO 2 max by 6% and relative VO 2 max by 5% (Figure). Maximal Q c did not change after MIE but increased in all HIE patients (+1.2L/min, 95% CI -1.4 to 3.9), while maximal av-O 2 diff remained stable in both groups. Training compliance was 84 ± 15% in HIE and 93 ± 11% in MIE. There were no serious exercise-related adverse events in either group though two HIE subjects had arrhythmias at rest: 1) 14-beat run of wide complex tachycardia of uncertain mechanism given underlying conduction disease prior to a training session, and 2) 11 beats of non-sustained ventricular tachycardia prior to post exercise testing. Conclusions: Preliminary findings show that five months of HIE safely and consistently increased cardiorespiratory fitness in patients with HCM, though overall the improvements were comparable to MIE.

Multislice left ventricular ejection fraction prediction from cardiac MRIs without segmentation using shared SptDenNet

We propose a spatiotemporal model for cardiac magnetic resonance images (MRI) named SptDenNet. The proposed model is based on DenseNet and extracts spatial and temporal features simultaneously to exploit three-dimensional information on the heart over the cardiac loop cycle. To balance the model performance and efficiency, we construct a shared end-to-end framework, in which all frames of each selected short-axis (SAX) view slices are input to SptDenNet individually to extract spatiotemporal features. Then, the extracted features of all selected SAX view slices of a patient are concatenated and input to the subsequent fully connected layer and then a softmax layer to predict the left ventricular ejection fraction directly. To address the problem of class imbalance, we use FocalLoss function by reshaping the standard cross-entropy loss such that it down-weights the loss assigned to well-classified samples. We validate our proposed framework on the Second Annual Data Science Bowl dataset. Our prediction for the left ventricular ejection fraction obtains results comparable with state-of-the-art end-to-end approaches but without segmentation. The average mean absolute error of the ejection fraction is 6.84. To further verify the effectiveness of the proposed framework, we use 4-chamber view images from the same dataset to predict the cardiac function; we obtain an accuracy of 86.07%. Our approach constructs an end-to-end model to predict the ejection fraction automatically without using image segmentation, which helps reduce manual work. Moreover, the proposed approach is computationally efficient.

Novel in vivo and in vitro mechanisms of positive inotropic effect of atractylodin.

This study was to investigate the inotropic effect of atractylodin and its underlying mechanism. The cardiac pressure-volume loop (P-V loop), Langendroff-perfused isolated rat heart, patch-clamp, Ca2+ transient and western blot techniques were used. The results demonstrated that atractylodin (3mg/kg, ip) remarkably increased the left ventricular stroke work, cardiac output, stroke volume, heart rate, ejection fraction, end-systolic pressure, peak rates of rise and fall of left ventricular pressures (+dP/dtmax , -dP/dtmax ), the slopes of end-systolic pressure-volume relationship (also named as end-systolic elastance, Ees) and reducing end-systolic volume and end-diastolic volume in the in vivo rat study. Also, atractylodin (3mg/kg, ip) significantly decreased diastolic blood pressure and the arterial elastance (Ea) without significant systolic blood pressure change. In addition, atractylodin (0.1, 1, 10µmol/L) also increased the isolated rat heart left ventricular developed pressure which is the difference between the systolic and diastolic pressure in non-pacing and pacing modes. Furthermore, JMV-2959 (1μmol/L), a ghrelin receptor unbiased antagonist, blocked the increased left ventricular developed pressure of atractylodin in isolated rat hearts. Finally, atractylodin (5µmol/L) increased the amplitude of Ca2+ transient by enhancing SERCA2a activity, the sarcoplasmic reticulum Ca2+ content and the phosphorylation of phospholamban at 16-serine. These results demonstrated that atractylodin had a positive inotropic effect by enhancing SERCA2a activity which might be mediated by acting ghrelin receptor in myocardium. In conclusion, atractylodin which had the positive inotropic effect and decreased diastolic blood pressure might serve as an agent for the treatment of heart failure in clinical settings.

Cardiogenesis with a focus on vasculogenesis and angiogenesis.

The initial intraembryonic vasculogenesis occurs in the cardiogenic mesoderm. Here, a cell population of proendocardial cells detaches from the mesoderm that subsequently generates the single endocardial tube by forming vascular plexuses. In the course of embryogenesis, the endocardium retains vasculogenic, angiogenic and haematopoietic potential. The coronary blood vessels that sustain the rapidly expanding myocardium develop in the course of the formation of the cardiac loop by vasculogenesis and angiogenesis from progenitor cells of the proepicardial serosa at the venous pole of the heart as well as from the endocardium and endothelial cells of the sinus venosus. Prospective coronary endothelial cells and progenitor cells of the coronary blood vessel walls (smooth muscle cells, perivascular cells) originate from different cell populations that are in close spatial as well as regulatory connection with each other. Vasculo- and angiogenesis of the coronary blood vessels are for a large part regulated by the epicardium and epicardium-derived cells. Vasculogenic and angiogenic signalling pathways include the vascular endothelial growth factors, the angiopoietins and the fibroblast growth factors and their receptors.

On the Cardiac Loop and Its Failing: Left Ventricular Outflow Tract Obstruction.

On the Cardiac Loop and Its Failing: Left Ventricular Outflow Tract Obstruction.

1167 Atrial strain predicts exercise capacity in patients with the fontan circulation

Abstract Funding Acknowledgements None Introduction Atrial function has recently emerged as a valuable parameter, particularly for evaluation of ventricular diastolic dysfunction and heart failure. There is a strong need for reliable echocardiographic predictors of exercise capacity in univentricular hearts, but their particular anatomy makes it challenging. In this work we aimed to characterize the relationship between atrial strain and exercise parameters in the Fontan population. Methods Fontan patients followed in our outpatient clinic were prospectively evaluated with cardiopulmonary exercise test and transthoracic echocardiogram. The dominant atrium, i.e. the atrium connected to the dominant atrioventricular valve, was assessed with speckle-tracking echocardiography for active (εact), conduit (εcon), and reservoir (εres) strain; and εact/εres ratio. A single cardiac loop from the 4 chamber view was selected for this analysis and the ‘zero’ strain reference for atrial deformation analysis was set at the onset of the electrocardiogram P wave. Exercise capacity defined as the percentage of peak oxygen uptake (VO2), comparing with predicted values, was chosen as the dependent variable. Independent variables were selected among clinical and echocardiographic data. Statistical analysis was performed using SPSS version 23. T-student test was used for binomial and continuous variable correlation; single and multivariable linear regression was used for continuous variable correlation. Statistical significance was defined as p-value < 0.05. Results Fifty-two Fontan patients were assessed. Nineteen (37%) were excluded due to inadequate deformation tracking of the atrial wall. Mean age was 18.0 years (SD 6.9, min. 10.0 - max. 36.0), mean age at Fontan surgery was 7.0 years (SD 2.9, min. 3.0 – max. 18.0). Peak VO2 as a percentage of the predicted value was 66.5% (SD 18.8, min. 36.4 – max. 118.6). εact was -11.1% (SD 3.7, min. -21.1 – max. -4.8), εcon was 10.6% (SD 6.5, min. -0.5 – max. 6.5), εres was 21.7% (SD 5.2, min. 13.2 – max. 34.4) and εact/εres ratio was 0.54 (SD 0.23, min. 0.22 – max. 1.04). On univariate analysis, all atrial strain variables correlated with peak VO2. After adjusting for collinearity, multivariable regression defined age (estimate -1.6, 95% CI: -2.5 to -0.9, p-value < 0.001) and εact strain (estimate 1.8, 95% CI: 0.5 to 3.2, p-value = 0.011) as the strongest predictors of peak VO2 (r2= 0.479). Conclusion Peak VO2 defines exercise capacity and is a strong marker of prognosis in Fontan patients. There are very few echocardiographic variables capable of predicting it, in part due to a variable cardiac anatomy. We showed that atrial strain rate is a novel echocardiographic parameter that predicts peak VO2. In the Fontan circulation, a higher reliance on active atrial contraction for ventricular filling predicts lower exercise capacity. Therefore, atrial strain rate, whenever measurable, may provide a new method of risk stratification in this population. Abstract 1167 Figure. Example of atrial strain curve.

Activation of cardiac AMPK-FGF21 feed-forward loop in acute myocardial infarction: Role of adrenergic overdrive and lipolysis byproducts

Fibroblast growth factor 21 (FGF21) is a metabolic hormone having anti-oxidative and anti-hypertrophic effects. However, the regulation of FGF21 expression during acute myocardial infarction (AMI) remains unclear. We tested blood samples from 50 patients with AMI and 43 patients with stable angina pectoris (sAP) for FGF21, fatty acid binding protein 4 (FABP4), a protein secreted from adipocytes in response to adrenergic lipolytic signal, and total and individual fatty acids. Compared with sAP patients, AMI patients had higher serum FGF21 levels on admission, which were significantly correlated with peak FABP4 and saturated fatty acids (SFAs) but not with peak levels of cardiac troponin T. In mice, myocardial ischemia rapidly induced FGF21 production by the heart, which accompanied activation of AMP-activated protein kinase (AMPK)-dependent pathway. Like AICAR, an activator of AMPK, catecholamines (norepinephrine and isoproterenol) and SFAs (palmitate and stearate) significantly increased FGF21 production and release by cardiac myocytes via AMPK activation. Recombinant FGF21 induced its own expression as well as members of down-stream targets of AMPK involved in metabolic homeostasis and mitochondrial biogenesis in cardiac myocytes. These findings suggest that adrenergic overdrive and resultant adipose tissue lipolysis induce cardiac AMPK-FGF21 feed-forward loop that potentially provides cardioprotection against ischemic damage.

A Porcine Model Comparing NRP and Cold Storage versus NRP and Ex-Situ Perfusion in the Distant Procurement of DCD Hearts

Purpose Heart donation after circulatory death (DCD) has significantly improved organ utilisation with promising early outcomes. To date, adult DCD heart programmes have relied largely on ex-situ heart perfusion during transport of the donor organs even after normothermic regional perfusion (NRP) in the donor where the heart is formally assessed after circulatory arrest. In this pre-clinical porcine study we compare the use of cold storage as an alternative to ex-situ heart perfusion following NRP. Methods The porcine model of DCD was established with hypoxic arrest after baseline functional measurements were taken including thermo-dilution cardiac studies and pressure-volume loop measurements. Following mechanical asystole a fixed warm ischaemic period was allowed to model for the observation period and the time taken for transfer and access to the heart and major vessels in the clinical setting. NRP was established and the hearts perfused for 60 minutes before being weaned from NRP and functionally assessed. The hearts were then subject to cold storage (CS) with cardioprotective flush or ex-situ heart perfusion (ESHP) for 2 hours. The hearts were then functionally assessed on a left sided working rig with pressure-volume loop measurements. Results There were 5 animals in the NRP+CS and 6 in the NRP+ESHP groups respectively. All NRP+CS hearts and 5 out of the 6 NRP+ESHP were able to function in working mode for assessment on the rig with the left side loaded to a left atrial pressure of 20mmHg (Table 1). Conclusion These data suggest that NRP sufficiently resuscitates DCD hearts to allow for cold storage following functional assessment. In the porcine model, ESHP did not appear to offer any added advantage over conventional CS of 2 hours. Further work is required to determine the upper limit of cold ischaemic time that would be tolerated by the DCD heart and we should be cautious in extending CS until we have further information to guide us in the longer usage of CS after NRP.

Abstract 120: Measures of Coagulation and Hemostatic Activation Outperform Left Atrial Structural Parameters in Identifying Embolic Stroke of Undetermined Source (ESUS) Patients Who May Benefit From Early Anticoagulation

Introduction: The objective of this study was to evaluate left atrial (LA) echocardiographic parameters and a novel panel of serum biomarkers to identify ESUS patients who may benefit from early anticoagulation. Methods: We prospectively identified ESUS patients seen in the Emory Clinic from January 1, 2015 to June 30, 2017 who underwent prolonged cardiac monitoring with mobile cardiac outpatient telemetry (MCOT) and/or implantable loop recorder (ILR). In a subset of consecutive patients, 4 measures of coagulation and hemostatic activation (MOCHA) including d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex and fibrin monomer were obtained ≥ 2 weeks after the index stroke and repeated if abnormal. We evaluated the ability of LA structural parameters to identify patients with atrial fibrillation (AF) on monitoring and the ability of abnormal MOCHA levels to identify patients who had the composite outcome of newly diagnosed AF, malignancy, or recurrent stroke. Results: During the study period, 92 ESUS patients (mean age 64 +/- 15 years, 54% female, 62% non-white, mean follow-up 1.4 +/- 0.8 years) underwent prolonged cardiac monitoring (65% MCOT, 62% ILR, 38% MCOT+ILR); 16 (17%) were found to have AF. Severe LA enlargement (vs normal) was associated with subsequent detection of AF (p=0.09) however LA diameter and LA volume index were not. Baseline characteristics of ESUS patients who underwent MOCHA testing (n=44) were similar to patients who did not except that those tested were younger (60 vs 67 years, p=0.04); over mean follow-up of 1.2 +/- 0.8 years, 18 (41%) patients had newly diagnosed AF, malignancy or recurrent stroke. ESUS patients with persistently abnormal (vs normal) MOCHA levels were significantly more likely to have newly diagnosed AF, malignancy or recurrent stroke (OR 11.3, 95% CI 2.5-50.1, p=0.001); elevated levels of ≥ 3 MOCHA markers had a 67% sensitivity and 81% specificity for identifying patients with the composite outcome. Conclusion: Abnormal MOCHA levels identified ESUS patients who were more likely to have newly diagnosed AF, malignancy or recurrent stroke over follow-up and may be more effective than LA structural abnormalities in identifying patients who could benefit from early anticoagulation.

Cardiac pacing and devices: history, technologies and current innovations

This article summarises the history of cardiac pacing, from major early scientific developments to implantable pacing systems. Advances in batteries, leads, electromagnetics and programming in pacing are traced, and there is an up-to-date appraisal of innovations. There is a review of cardiac devices developed from pacing technology, including biventricular pacemakers for heart failure, implantable cardioverter defibrillators to prevent sudden cardiac death, leadless pacemakers and implantable loop recorders. The aim of the article is to give an overview of cardiac devices, one of the major technological advances over the past 85 years.

Reveal LINQ Versus Reveal XT Implantable Loop Recorders: Intra- and Post-Procedural Comparison

To compare the procedure, recovery, hospitalization times, and costs along with patient/parent satisfaction after newer-generation cardiac implantable loop recorder (Reveal LINQ; Medtronic Inc, Minneapolis, Minnesota) and previous-generation implantable loop recorder (Reveal XT; Medtronic Inc). A prospective study of patients undergoing LINQ implantations between April 2014 and October 2015 was performed. Retrospective chart review of patients undergoing XT implantations was performed for comparison. Thirty-one patients received LINQ and 15 patients received XT. Indications included syncope/palpitations (28/46, 61%), history of arrhythmias (9/46, 20%), arrhythmia burden in congenital heart disease (5/46, 10%), and monitoring in channelopathies (4/46, 9%). The LINQ group underwent more conscious sedation procedures than the XT group (8/31 vs 0/15, P = .04) with shorter procedural time (9 vs 34 minutes, P <.001), room occupation time (38 vs 81 minutes, P <.001), recovery time (21 vs 67 minutes, P <.001), and total hospital time (214 vs 264 minutes, P = .046). The LINQ group also had shorter return to activity time (2 vs 5 days, P = 1). Three device erosions in the LINQ group required reintervention. The LINQ group had fewer body image issues than the XT group (1/26 vs 5/14, P = .01) with both groups scoring 5/5 overall patient/parent satisfaction score at follow-up. Both groups had comparable total direct hospital costs (US $5905 vs $5438, P = .8). LINQ offers better procedural and recovery time compared with XT. LINQ implantations under conscious sedation reduce total hospitalization time.

Transmission Rates of Implantable Loop Recorders with Remote Monitoring Follow-Up

Introduction: Implantable cardiac loop recorders (ILRs) are implanted to help establish a correlation between symptoms and cardiac arrhythmias in patients suffering from recurrent syncope of unknown aetiology. The Reveal LINQ ILR has increased remote monitoring capabilities and allows automatic transmissions for the detection of atrial fibrillation, bradycardia, tachycardia, and pauses of programmable rates/duration, as well as patient initiated transmissions. Methods: 33 patients (20 reveal LINQ: 13 Reveal DX/XT) are followed up via our remote monitoring service. We retrospectively analysed the total number of transmissions, including routine, patient initiated and episode initiated transmissions over a six-month period between June and December 2015. Transmissions were further analysed, and classified as being appropriate or inappropriate due to over sensing, under sensing or signal drop out. Results: Over the six-month period 294 remote transmissions were received for ILRs (275 LINQ: 19 Reveal DX/XT). The median number of transmissions per patient, per year was 37.3 for LINQ compared to 3.5 for Reveal DX/XT. Of the 275 LINQ transmissions, 216 were automatic transmissions, 59 were patient initiated. 46.5% of all transmissions and 59.6% of all automatic transmissions were deemed inappropriate. Inappropriate episodes were documented in 9 of the 20 LINQ patients. Conclusion: There is an increased transmission rate associated with LINQ when compared to Reveal DX/XT when followed up with remote monitoring. While there is improved availability of events with LINQ, a substantial portion of LINQ transmissions occur due to misdiagnosis of a rhythm by the device.

Mimicking the cardiac cycle in intact cardiomyocytes using diastolic and systolic force clamps; measuring power output.

AimsA single isolated cardiomyocyte is the smallest functional unit of the heart. Yet, all single isolated cardiomyocyte experiments have been limited by the lack of proper methods that could reproduce a physiological cardiac cycle. We aimed to investigate the contractile properties of a single cardiomyocyte that correctly mimic the cardiac cycle.Methods and resultsBy adjusting the parameters of the feedback loop, using a suitably engineered feedback system and recording the developed force and the length of a single rat cardiomyocyte during contraction and relaxation, we were able to construct force–length (FL) relations analogous to the pressure–volume (PV) relations at the whole heart level. From the cardiac loop graphs, we obtained, for the first time, the power generated by one single cardiomyocyte.ConclusionHere, we introduce a new approach that by combining mechanics, electronics, and a new type optical force transducer can measure the FL relationship of a single isolated cardiomyocyte undergoing a mechanical loop that mimics the PV cycle of a beating heart.

Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice.

Cardiac pressure-volume loop analysis is the "gold-standard" in the assessment of load-dependent and load-independent measures of ventricular systolic and diastolic function. Measures of ventricular contractility and compliance are obtained through examination of cardiac response to changes in afterload and preload. These techniques were originally developed nearly three decades ago to measure cardiac function in large mammals and humans. The application of these analyses to small mammals, such as mice, has been accomplished through the optimization of microsurgical techniques and creation of conductance catheters. Conductance catheters allow for estimation of the blood pool by exploiting the relationship between electrical conductance and volume. When properly performed, these techniques allow for testing of cardiac function in genetic mutant mouse models or in drug treatment studies. The accuracy and precision of these studies are dependent on careful attention to the calibration of instruments, systematic conduct of hemodynamic measurements and data analyses. We will review the methods of conducting pressure-volume loop experiments using a conductance catheter in mice.

Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice

Cardiac pressure-volume loop analysis is the “gold-standard” in the assessment of load-dependent and load-independent measures of ventricular systolic and diastolic function. Measures of ventricular contractility and compliance are obtained through examination of cardiac response to changes in afterload and preload. These techniques were originally developed nearly three decades ago to measure cardiac function in large mammals and humans. The application of these analyses to small mammals, such as mice, has been accomplished through the optimization of microsurgical techniques and creation of conductance catheters. Conductance catheters allow for estimation of the blood pool by exploiting the relationship between electrical conductance and volume. When properly performed, these techniques allow for testing of cardiac function in genetic mutant mouse models or in drug treatment studies. The accuracy and precision of these studies are dependent on careful attention to the calibration of instruments, systematic conduct of hemodynamic measurements and data analyses. We will review the methods of conducting pressure-volume loop experiments using a conductance catheter in mice.

Graz Critical Limb Ischemia Score: A Risk Score for Critical Limb Ischemia in Peripheral Arterial Occlusive Disease.

Critical limb ischemia (CLI), a frequently encountered disorder, is associated with a high rate of limb amputation and mortality. To identify patients at high risk for CLI, we developed a simple risk score for peripheral arterial occlusive disease (PAOD).In our cross-sectional study, we first evaluated 1000 consecutive PAOD patients treated at our institution from 2005 to 2007, documenting clinical symptoms, comorbidities, and concomitant medication. We calculated odds ratios (OR) in a binary logistic regression model to find possible risk factors for CLI. We then verified the score in a second step that included the 1124 PAOD patients we treated between 2007 and 2011.In the first patient group, the greatest risk factors for CLI were age ≥75 years (OR 2.0), type 2 diabetes (OR 3.1), prior myocardial infarction (OR 2.5), and therapy with low molecular weight heparins (2.8). We scored 1 point for each of those conditions. One point was given for age between 65 and 75 years (OR 1.6) as well as for therapy with cardiac glycosides (OR 1.9) or loop diuretic therapy (OR 1.5). As statin therapy was protective for CLI with an OR of 0.5, we subtracted 1 point for those patients.In the second group, we could prove that frequency of CLI was significantly higher in patients with a high CLI score. The score correlated well with inflammatory parameters (c-reactive protein and fibrinogen). We were also able to define 3 different risk groups for low (score −1 to 1), intermediate (score 2–4), and high CLI risk (score >4).We developed a simple risk stratification scheme that is based on conditions that can be easily assessed from the medical history, without any laboratory parameters. This score should help to identify PAOD patients at high risk for CLI.

Integration of cardiac monitoring with video to enable service transformation

The future of digital care will be significantly enhanced by the integration and interoperation of systems and services. Collaboration between clinicians and service providers will allow combined services to be shaped such that the whole is greater than the sum of the parts. In future services need to enable people to continue with their lives whilst being supported, rapidly and appropriately when required. We present the results of a project to use an innovative cardiac event loop recorder (ELR) and screening service in cooperation with the use of video consultations. The ELR service detects and records abnormal ECG traces. The connected consultant can choose to receive a PDF of any abnormal trace within seconds or have the trace pre-screened by a cardiac physiologist. The consultant can then initiate a video call to the person and discuss the event. The patient might then attend a consultation in person. The goal is to significantly improve the detection of abnormal events and offer immediacy of support and diagnosis i.e. quality improvement by early diagnosis and potential cost saving in the immediate term by reducing surveillance appointments and in the long term by reducing burden of disease e.g. stroke reduction by earlier AF detection This approach facilitates two modes of care delivery that are innovative: The first is the capture of infrequent events. An example case involved a 66-year-old hypertensive female who suffered from 2 years history of palpitations and had been treated for anxiety and ventricular ectopic beats. Physical examination was normal. Echocardiography showed structurally normal heart. Her electrocardiogram showed normal sinus rhythm with normal PR and QT segments Since several 24 hours Holter monitoring episodes had proved to be unsuccessful in the past it was decided to monitor the patient with the smart event ELR. The patient was equipped with a one-channel smart ELR that was used over a period of 2 weeks of continuous monitoring. The recorder was programmed to automatically send both manually triggered cardiac events as well as automatically triggered events for atrial fibrillation (AF). For the latter, the automatic AF detection algorithm had been activated. All events were automatically transferred using GPRS (tele-ECG option) and in virtually real time. International Digital Health and Care Congress, The King’s Fund, London, September 10-12 2014. International Journal of Integrated Care – Volume 14, 01 November – URN:NBN:NL:UI:10-1-116508– http://www.ijic.org/ Over the course of the next days the recorder sent in ECGs, which showed clear evidence of paroxysmal atrial fibrillation (PAF) as a cause of her intermittent palpitation. During these episodes, she felt unwell with erratic heart rate and light-headedness. The episodes lasted between 30 seconds and up to 2 minutes, confirming the diagnosis of PAF. For patients with long-term conditions that include cardiovascular disease the approach offers a pro-active and supportive way to manage people in their own homes. Both approaches address several of the NHS Outcomes Framework domains, specifically: • reducing premature mortality. • ensuring people feel supported to manage their condition. • reducing the amount of time spent in hospital. • improving people’s experience of outpatient care. • improving hospital’s responsiveness to patient’s needs. During the presentation there will be a live demonstration of the cardiac monitoring and the video service.

Cardiac T 1 Imaging

T(1) mapping of the heart has evolved into a valuable tool to evaluate myocardial tissue properties, with or without contrast injection, including assessment of myocardial edema and free water content, extracellular volume (expansion), and most recently cardiomyocyte hypertrophy. The magnetic resonance imaging pulse sequence techniques developed for these applications have had to address at least 2 important considerations for cardiac applications: measure magnetization-inversion recoveries during cardiac motion with sufficient temporal resolution for the shortest expected T(1) values, and, second, obtain these measurements within a time during which a patient can comfortably suspend breathing. So-called Look-Locker techniques, and variants thereof, which all sample multiple points of a magnetization recovery after each magnetization preparation, have therefore become a mainstay in this field. The rapid pace of advances and new findings based on cardiac T(1) mapping for assessment of diffuse fibrosis or myocardial edema show that these techniques enrich the capabilities of magnetic resonance imaging for myocardial tissue profiling, which is arguably unmatched by other cardiac imaging modalities.

Obesity Is Associated with Lower Coronary Microvascular Density

BackgroundObesity is associated with diastolic dysfunction, lower maximal myocardial blood flow, impaired myocardial metabolism and increased risk of heart failure. We examined the association between obesity, left ventricular filling pressure and myocardial structure.MethodsWe performed histological analysis of non-ischemic myocardium from 57 patients (46 men and 11 women) undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation or loop diuretic therapy.ResultsNon-obese (body mass index, BMI, ≤30 kg/m2, n=33) and obese patients (BMI >30 kg/m2, n=24) did not differ with respect to myocardial total, interstitial or perivascular fibrosis, arteriolar dimensions, or cardiomyocyte width. Obese patients had lower capillary length density (1145±239, mean±SD, vs. 1371±333 mm/mm3, P=0.007) and higher diffusion radius (16.9±1.5 vs. 15.6±2.0 μm, P=0.012), in comparison with non-obese patients. However, the diffusion radius/cardiomyocyte width ratio of obese patients (0.73±0.11 μm/μm) was not significantly different from that of non-obese patients (0.71±0.11 μm/μm), suggesting that differences in cardiomyocyte width explained in part the differences in capillary length density and diffusion radius between non-obese and obese patients. Increased BMI was associated with increased pulmonary capillary wedge pressure (PCWP, P<0.0001), and lower capillary length density was associated with both increased BMI (P=0.043) and increased PCWP (P=0.016).ConclusionsObesity and its accompanying increase in left ventricular filling pressure were associated with lower coronary microvascular density, which may contribute to the lower maximal myocardial blood flow, impaired myocardial metabolism, diastolic dysfunction and higher risk of heart failure in obese individuals.