The critical isthmus of left atrial anterior wall flutter is mostly circumscribed into a small area immediately behind the aortic root. Implications for catheter ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial flutters (LAFL) are typically observed in patients with previous ablation lines or surgery in the left atrium (LA). Less frequently, scar-related left atrial anterior wall (LAAW) flutters may occur. Although the presence of low-voltage areas (LVAs, a surrogate of scar) in the LA is considered an arrhythmogenic substrate and a marker of atrial cardiomyopathy, the pathophysiologic factors responsible for its formation remain unclear. We hypothesized that compression of the LAAW by the aortic root could be responsible of LVAs found in the LAAW, and therefore, be the substrate for the development of LAAW flutter.

Purpose

We aimed to describe: 1) the relationship between the aortic root and the presence of LVAs in the LAAW, which is the substrate for reentry; and 2) the clinical and electrophysiological characteristics of LAAW atrial flutter.

Methods

Consecutive patients referred for LAFL ablation between April 2019 and September 2022 in a single center were retrospectively collected. Among 55 patients with LAFL, 10 (18%) demonstrated a macroreentrant circuit with a critical isthmus identified in the LAAW, in the absence of previous ablation lines or surgery, and were included in the analysis. Previous pulmonary vein isolation (PVI) was not an exclusion criterion. All patients underwent a multidetector computerized tomography (MDCT) prior to the procedure and the images were analyzed using ADAS 3DTM imaging platform. Activation mapping was performed in all patients using a multielectrode mapping catheter and CARTO 3 navigation system.

Results

9 of 10 patients were male (mean age 74,3 ± 6,3 years). LA enlargement was present in all patients (48,3 ± 4,7 mm) and the mean aortic root diameter was 34,8 ± 3,4 mm. The mean LAAW flutter cycle length was 293,4 ± 68,3 ms. In 9 of the patients (90%), the LAAW flutter critical isthmus was just behind the aortic root, separated by < 1 mm according to the LA-aortic root fingerprinted isodistance map (mean fingerprinted isodistance area was 5,8 ± 2,5 cm2). The remaining patient had the critical isthmus just below the aortic root, between the area in contact with the latter and the mitral annulus. Furthermore, in all cases, the critical isthmus was immersed in LVAs. All but 1 LAAW flutter terminated during radiofrequency (RF) energy applications and rendered it non-inducible. After a median follow-up of 13,6 months (IQ range 5,3-21,6), 7 patients (70%) remained without recurrences.

Conclusion

In patients with LAAW atrial flutter, the presence of LVAs and the critical isthmus of the tachycardia are mostly circumscribed into small areas immediately behind the aortic root. Knowledge of this close relationship and the use of the isodistance map could be useful when mapping and ablating LAAW flutter, helping to straightforward the ablation procedure.

Metrics of Gender Differences in Mortality Risk after Diabetic Foot Disease

BACKGROUND

The aim of this study was to clarify any gender differences in the mortality risk of people with DFD since patients with diabetic foot disease (DFD) are at a high risk of mortality and, at the same time, are more likely to be men.

METHODS

From regional administrative sources, the survival probability was retrospectively evaluated by the Kaplan-Meier method and using the Cox proportional-hazards model comparing people with DFD to those without DFD across the years 2011-2018 in Tuscany, Italy. Gender difference in mortality was evaluated by the ratio of hazard ratios (RHR) of men to women after initial DFD hospitalizations (n = 11,529) or in a cohort with prior history of DFD hospitalizations (n = 11,246).

RESULTS

In both cohorts, the survival probability after DFD was lower among women. Compared to those without DFD, after initial DFD hospitalizations, the mortality risk was significantly (18%) higher for men compared to women. This excess risk was particularly high after major amputations but also after ulcers, infections, gangrene, or Charcot, with a lower reduction after revascularization procedures among men. In the cohort that included people with a history of prior DFD hospitalizations, except for the risk of minor amputations being higher for men, there was no gender difference in mortality risk.

CONCLUSIONS

In people with DFD, the overall survival probability was lower among women. Compared to those without DFD after a first DFD hospitalization, men were at higher risk of mortality. This excess risk disappeared in groups with a history of previous DFD hospitalizations containing a greater percentage of women who were older and probably had a longer duration of diabetes and thus becoming, over time, progressively frailer than men.

COVID-19 Detection Using Photoplethysmography and Neural Networks

The early identification of microvascular changes in patients with Coronavirus Disease 2019 (COVID-19) may offer an important clinical opportunity. This study aimed to define a method, based on deep learning approaches, for the identification of COVID-19 patients from the analysis of the raw PPG signal, acquired with a pulse oximeter. To develop the method, we acquired the PPG signal of 93 COVID-19 patients and 90 healthy control subjects using a finger pulse oximeter. To select the good quality portions of the signal, we developed a template-matching method that excludes samples corrupted by noise or motion artefacts. These samples were subsequently used to develop a custom convolutional neural network model. The model accepts PPG signal segments as input and performs a binary classification between COVID-19 and control samples. The proposed model showed good performance in identifying COVID-19 patients, achieving 83.86% accuracy and 84.30% sensitivity (hold-out validation) on test data. The obtained results indicate that photoplethysmography may be a useful tool for microcirculation assessment and early recognition of SARS-CoV-2-induced microvascular changes. In addition, such a noninvasive and low-cost method is well suited for the development of a user-friendly system, potentially applicable even in resource-limited healthcare settings.

Automatic COVID-19 severity assessment from HRV

COVID-19 is known to be a cause of microvascular disease imputable to, for instance, the cytokine storm inflammatory response and the consequent blood coagulation. In this study, we propose a methodological approach for assessing the COVID-19 presence and severity based on Random Forest (RF) and Support Vector Machine (SVM) classifiers. Classifiers were applied to Heart Rate Variability (HRV) parameters extracted from photoplethysmographic (PPG) signals collected from healthy and COVID-19 affected subjects. The supervised classifiers were trained and tested on HRV parameters obtained from the PPG signals in a cohort of 50 healthy subjects and 93 COVID-19 affected subjects, divided into two groups, mild and moderate, based on the support of oxygen therapy and/or ventilation. The most informative feature set for every group's comparison was determined with the Least Absolute Shrinkage and Selection Operator (LASSO) technique. Both RF and SVM classifiers showed a high accuracy percentage during groups' comparisons. In particular, the RF classifier reached 94% of accuracy during the comparison between the healthy and minor severity COVID-19 group. Obtained results showed a strong capability of RF and SVM to discriminate between healthy subjects and COVID-19 patients and to differentiate the two different COVID-19 severity. The proposed method might be helpful for detecting, in a low-cost and fast fashion, the presence and severity of COVID-19 disease; moreover, these reasons make this method interesting as a starting point for future studies that aim to investigate its effectiveness as a possible screening method.

The Assessment of Ankle Range-of-Motion and Its Relationship with Overall Muscle Strength in a Cross-Section of Soccer Players

Soccer (football) practice can induce a limitation of ankle range of motion (ROM) that is a possible risk factor for injury and other negative consequences over time. The main objective of this research was to investigate the effects of soccer practice on ankle ROM throughout the entire period of a sports career of soccer players (SP). Furthermore, the relationship between ankle ROM and muscle strength in SP of different ages was studied. A total of 204 SP (range 6.7−45.1 years) and 87 controls (range: 7.5−45.2 years) matched for age, body mass index (BMI), and gender, were assessed. Ankle ROM in both plantar flexion (APF) and dorsiflexion (ADF) in addition to handgrip strength (HGS) were evaluated using an inclinometer and the Jamar hydraulic hand dynamometer, respectively. The comparison between SP and control groups showed a significant reduction in ankle ROM of both APF (26.3 ± 7.2° vs. 32.6 ± 7.4°; d = −0.90; p < 0.001) and ADF (95.5 ± 15.6° vs. 105.5 ± 15.8°; d = −0.66; p < 0.001). In SP, the results of the ANOVAs test indicate that age had a significant effect on ADF (F = 4.352, p = 0.038, partial eta-squared (ηp2) = 0.015) but not on APF (F = 0.430, p = 0.746, ηp2 = 0.001). Moreover, considering only the SP, a weak inverse correlation between ADF and HGS group ADF was found (rs = −0.27; p < 0.001). Factors such as the non-linear trend of growth in young SP could hinder the definition of the relationship between ankle ROM, age, and muscle strength. However, the appropriate consideration of age and muscle strength could facilitate the management of ankle ROM in PF of different ages.

Barbell load distribution and lifting velocity affect bench press exercise volume and perceived exertion

OBJECTIVE

The intensity of barbell bench press exercise is generally prescribed as the load to be lifted for a specific number of repetitions; however, other factors (e.g., execution velocity) can affect bench press exercise intensity. Moreover, no study assessed whether load distribution (i.e., the distance between the disc stacks on the two sides of the barbell) affects exercise intensity. The present study aims to assess how different combinations of load, velocity, and barbell load distribution affect the number of repetitions to failure (REPfailure), and rating of perceived exertion (RPEfatigue) and number of repetitions (REPfatigue) at fatigue onset.

METHODS

Ten males (age 23.3±1.8 years) performed bench press exercises to exhaustion using random combinations of three loads (50%, 65%, and 80% of 1 repetition maximum), three execution velocities (50%, 70%, and 90% of maximal concentric velocity), and two load distributions (narrow and wide). Three separate three-way repeated-measures ANOVAs were performed to assess the effect of load, velocity, and load distribution on REPfailure, RPEfatigue, and REPfatigue expressed as a percentage of REPfailure.

RESULTS

REPfailure was affected by load (p<0.001), velocity (p<0.001), and distribution (p = 0.005). The interactions between load and velocity (p<0.001) and load and distribution (p = 0.004) showed a significant effect on REPfailure, whereas the interaction between velocity and distribution was not significant (p = 0.360). Overall, more REPfailure were performed using lower loads, higher velocities, and a wider distribution. RPEfatigue and REPfatigue were affected by load (p<0.001 and p = 0.007, respectively) and velocity (p<0.001 and p<0.001, respectively), and not by distribution (p = 0.510 and p = 0.571, respectively) or the two-way interaction effects. Overall, using higher loads yielded higher RPEfatigue but lower REPfatigue, while RPEfatigue and REPfatigue were higher when slower velocities were used.

CONCLUSION

The current investigation shows that not only load but also velocity and barbell load distribution may influence bench press training volume and perceived exertion.

COVID-19 detection using a model of photoplethysmography (PPG) signals

Objective:Coronavirus disease 2019 (COVID-19) targets several tissues of the human body; among these, a serious impact has been observed in the microvascular system. The aim of this study was to verify the presence of photoplethysmographic (PPG) signal modifications in patients affected by COVID-19 at different levels of severity.

Approach: The photoplethysmographic signal was evaluated in 93 patients with COVID-19 of different severity (46: grade 1; 47: grade 2) and in 50 healthy control subjects. A pre-processing step removes the long-term trend and segments of each pulsation in the input signal. Each pulse is approximated with a model generated from a multi-exponential curve, and a Least Squares fitting algorithm determines the optimal model parameters. Using the parameters of the mathematical model, three different classifiers (Bayesian, SVM and KNN) were trained and tested to discriminate among healthy controls and patients with COVID, stratified according to the severity of the disease. Results are validated with the leave-one-subject-out validation method.

Main results: Results indicate that the fitting procedure obtains a very high determination coefficient (above 99% in both controls and pathological subjects). The proposed Bayesian classifier obtains promising results, given the size of the dataset, and variable depending on the classification strategy. The optimal classification strategy corresponds to 79% of accuracy, with 90% of specificity and 67% of sensibility.

Significance:The proposed approach opens the possibility of introducing a low cost and non-invasive screening procedure for the fast detection of COVID-19 disease, as well as a promising monitoring tool for hospitalized patients, with the purpose of stratifying the severity of the disease.

Classifying sepsis from photoplethysmography

Sepsis is a life-threatening organ dysfunction. It is caused by a dysregulated immune response to an infection and is one of the leading causes of death in the intensive care unit (ICU). Early detection and treatment of sepsis can increase the survival rate of patients. The use of devices such as the photoplethysmograph could allow the early evaluation in addition to continuous monitoring of septic patients. The aim of this study was to verify the possibility of detecting sepsis in patients from whom the photoplethysmographic signal was acquired via a pulse oximeter. In this work, we developed a deep learning-based model for sepsis identification. The model takes a single input, the photoplethysmographic signal acquired by pulse oximeter, and performs a binary classification between septic and nonseptic samples. To develop the method, we used MIMIC-III database, which contains data from ICU patients. Specifically, the selected dataset includes 85 septic subjects and 101 control subjects. The PPG signals acquired from these patients were segmented, processed and used as input for the developed model with the aim of identifying sepsis. The proposed method achieved an accuracy of 76.37% with a sensitivity of 70.95% and a specificity of 81.04% on the test set. As regards the ROC curve, the Area Under Curve reached a value of 0.842. The results of this study indicate how the plethysmographic signal can be used as a warning sign for the early detection of sepsis with the aim of reducing the time for diagnosis and therapeutic intervention. Furthermore, the proposed method is suitable for integration in continuous patient monitoring.

Subcutaneous Implantable Defibrillator programming: an analysis of Italian clinical practice and its evolution

Background

The UNTOUCHED study (designed in 2017 and published in 2021) demonstrated high success rate for termination of ventricular arrhythmias, and very low inappropriate shock rate in subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients. The prescribed device programming included a conditional zone between 200 and 250 beats per minute (bpm) with discrimination algorithms employed to avoid delivering inappropriate shocks in this range, and a shock zone based on the rate alone for arrhythmias &gt;250 bpm. Whether these results influenced clinical practice is unknown.

Methods

We assessed the programming at implantation and changes in programmed parameters at follow-up (≥1 year) in a cohort of S-ICD recipients enrolled in the Rhythm Detect registry at 56 centers.

Results

From 2013 to 2021, 1521 consecutive patients (aged 49±15 years; 79% male, 52% dilated cardiomyopathy, 31% arrhythmic syndromes, 16% hypertrophic cardiomyopathy) were analyzed. At implantation, the programmed sensing vector was the Primary in 59% of patients, the Secondary in 35%, the Alternate in 6%. At follow-up, the sensed vector was changed in 13% of patients. The programmed conditional zone cutoff was set to 200 [200–220] bpm (median [25–75 percentile]), and the shock zone cutoff to 230 [210–250] bpm. At follow-up, the conditional zone cutoff was reprogrammed in 13% of patients, but the median value in the overall population did not change (200 [200–220] bpm; p&gt;0.05). The shock zone cutoff was reprogrammed in 43% of cases, and the overall median value was 250 [230–250] bpm (p&lt;0.001 versus implantation). Sorting patients by implantation date, we observed that in the first 764 patients (implanted ≤2017) the shock zone cutoff was set to 210 [210–230] bpm at implantation and to 240 [230–250] bpm at follow-up (reprogrammed in 66% of cases). While in patients implanted &gt;2017, it was already set to 250 [230–250] bpm at implantation and to 250 [240–250] bpm at follow-up (reprogrammed in 20% of cases, p&lt;0.001 versus ≤2017).

Conclusions

S-ICD programming parameters are rarely changed during follow-up (approximately 13% of patients). The only exception in clinical practice was the shock zone cutoff. Centers have begun to program high cutoffs in recent years. This happened at the time of implantation for new S-ICD recipients and at follow-up for pre-existing implants. This behavior is consistent with a substantial adoption of published trial findings and could contribute to reduce the incidence of inappropriate shocks in clinical practice.

Funding Acknowledgement

Type of funding sources: None.

Intermuscular technique for implantation of the subcutaneous implantable defibrillator: a propensity-matched case-control study

Background

A previous randomized study (PRAETORIAN) demonstrated that the subcutaneous implantable cardioverter–defibrillator (S-ICD) was noninferior to transvenous ICD with respect to device-related complications and inappropriate shocks. However, that was performed prior to the widespread adoption of pulse generator implantation in the intermuscular (IM) space instead of the traditional subcutaneous (SC) pocket.

Purpose

To compare survival from device-related complications and inappropriate shocks between patients who underwent S-ICD implantation with the generator positioned in an IM position in comparison with a SC pocket.

Methods

We analyzed 1577 consecutive patients who had undergone S-ICD implantation from 2013 to 2021 and were followed up until December 2021. SC patients were propensity-matched with patients of the IM group, and their outcomes were compared.

Results

SC implantations were performed in 367 (23%) patients. These patients were propensity-matched with 367 IM patients. Intra-procedural complications were reported in 9 (2.5%) patients in the SC Group and 7 (1.9%) in the IM Group. During a median follow-up of 29 months, device-related complications were reported in 55 (7.5%) patients and inappropriate shocks were reported in 54 (7.4%) patients. The risk of the composite primary endpoint was lower in the matched IM Group than in the SC Group (unadjusted hazard ratio 0.67, 95% CI 0.45–0.99, p=0.042), while the risk of appropriate shocks was similar between groups (unadjusted hazard ratio 0.99, 95% CI 0.60–1.64, p=0.976). There was no significant interaction between generator positioning and variables such as gender, age, body mass index, ejection fraction and generation of the device.

Conclusions

In this experience, IM S-ICD generator positioning was superior to SC positioning in reducing device-related complications and inappropriate shocks.

Funding Acknowledgement

Type of funding sources: None.

Real-world survival of model-3501 subcutaneous implantable defibrillator lead

Funding Acknowledgements

Type of funding sources: None.

Background

In December 2020, the subcutaneous implantable cardioverter-defibrillator (S-ICD) lead model-3501 was subject to a safety notification because of increased risk of fracture at a location just distal to the proximal sense ring. The manufacturer’s product performance report currently reports a lead survival probability of 98.8% at 45 months. However, no multicenter long-term performance information exists for this lead.

Purpose

Our aim was to assess the longevity of model-3501 leads and to compare it with that of the previous model-3401.

Methods

This analysis included consecutive patients who received an S-ICD with a model-3501 or a model-3401 lead at 66 Italian participating centers of the Rhythm Detect registry. A lead failed if it required extraction/replacement because of abnormalities suggestive of a structural defect, e.g. out-of-range impedance, nonphysiological electrical noise or ineffective therapy.

Results

From January 2013 to July 2021, 2403 patients were implanted and followed up (78% male, age 49±15years, ejection fraction 45±16%, body mass index 26±4Kg/m2). A 3501-model lead was used in 1697 patients and a 3401-model in 706 patients. During a median follow-up of 38 months [25th–75th percentile: 24-55], we detected 4 malfunctioning model-3501 leads and 2 model-3401 leads. After analysis of the returned leads by the manufacturer’s technical services, a single model-3501 lead failure was a fracture distal to the proximal ring electrode, as described in the manufacturer’s advisory letter. No deaths or permanent injuries occurred as a result of lead failures. The survival of 3501-model leads at 4 years was 99.5% (95% confidence interval, 99.0 to 99.9) compared with 99.9% (95% confidence interval, 99.6 to 100.0) of 3401-model leads (p=0.110). The cumulative occurrence rate of the 3501-model safety notification fracture was 0.1% (95% confidence interval, 0.0 to 0.3).

Conclusions

In this large multicenter analysis, the survival probability of model-3501 S-ICD leads was in line with that reported by the manufacturer, was not significantly lower than that of 3401-model leads (not affected by a safety notification), and still higher than that reported with transvenous leads. Although an enhanced electrode is now available, which addresses the potential for electrode body fracture, the present findings are reassuring and may have significant implications for the management of patients who have affected leads.

The subcutaneous ICD replacement in the clinical practice: preliminary observations from the multicentre RHYTHM DETECT

Funding Acknowledgements

Type of funding sources: None.

Background

Experience with the subcutaneous implantable cardioverter-defibrillator (S-ICD) is expanding rapidly. However, few data on generator replacement exist.

Purpose

The aim of this analysis was to describe the procedural characteristics of the pulse generator replacement in the current Italian practice and to provide a preliminary insight in the possible acute complications associated with first elective S-ICD generator replacements.

Methods

We analyzed 106 consecutive patients enrolled in the Rhythm Detect registry who underwent elective replacement of the S-ICD generator from September 2019 to July 2021. Procedures were accomplished according to the local clinical practice. A chest X-ray was performed, and the PRAETORIAN score was assessed and compared with the one measured after the first implantation.

Results

All replacements were performed in electrophysiology laboratories, 50% in day-hospital regimen, by 1 or 2 expert operators. Procedures were performed using local (87%) or general anaesthesia (13%). The median procedure duration was 40 (30-45) min. The previous S-ICD generator was in a subcutaneous pocket in 58 (55%) patients, and in an intermuscular pocket in the remaining patients. The PRAETORIAN score of the previous system was low (&lt;90) in 93% of patients and intermediate in 7% of patients. In all patients with the device in an intermuscular pocket, the PRAETORIAN score was &lt;90. During the replacement procedure, 22 S-ICD (3 with PRAETORIAN ≥90 before replacement) were removed from the initial subcutaneous position and placed in an intermuscular pocket. After replacement all patients with intermuscular devices had a score &lt;90, and the overall proportion of patients with low-risk PRAETORIAN score raised to 97%. Defibrillation testing was performed only in 10% of patients, while testing was performed in 77% of patients at the first implantation procedure. No procedure-related complications occurred.

Conclusions

S-ICD replacements seem easy to perform with no peri-procedural complications. The adoption of an intermuscular pocket is associated with optimal positioning according to the PREATORIAN score, and seems preferred also in many cases of generators previously placed subcutaneously. In the Italian clinical practice conversion testing is rarely performed at device replacement.

Vascular ageing and peripheral pulse: an improved model for assessing their relationship

Objective.Vascular ageing is associated with several alterations, including arterial stiffness and endothelial dysfunction. Such alterations represent an independent factor in the development of cardiovascular disease (CVD). In our previous works we demonstrated the alterations occurring in the vascular system are themselves reflected in the shape of the peripheral waveform; thus, a model that describes the waveform as a sum of Gaussian curves provides a set of parameters that successfully discriminate betweenunder(≤35 years old) andoversubjects (>35 years old). In the present work, we explored the feasibility of a new decomposition model, based on a sum of exponential pulses, applied to the same problem.Approach.The first processing step extracts each pulsation from the input signal and removes the long-term trend using a cubic spline with nodes between consecutive pulsations. After that, a Least Squares fitting algorithm determines the set of optimal model parameters that best approximates each single pulse. The vector of model parameters gives a compact representation of the pulse waveform that constitutes the basis for the classification step. Each subject is associated to his/her 'representative' pulse waveform, obtained by averaging the vector parameters corresponding to all pulses. Finally, a Bayesan classifier has been designed to discriminate the waveforms of under and over subjects, using the leave-one-subject-out validation method.Main results.Results indicate that the fitting procedure reaches a rate of 96% in under subjects and 95% in over subjects and that the Bayesan classifier is able to correctly classify 91% of the subjects with a specificity of 94% and a sensibility of 84%.Significance.This study shows a sensible vascular age estimation accuracy with a multi-exponential model, which may help to predict CVD.

Defibrillation testing of subcutaneous versus transvenous defibrillators in the clinical practice: a nationwide survey in Italy

Aims

According to current guidelines, defibrillation testing (DT) for efficacy can be omitted in patients undergoing transvenous implantable cardioverter–defibrillator (T-ICD) implantation. DT is still recommended for patients at risk for a high defibrillation threshold (e.g. hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, right-sided implantations) and for ICD generator changes. Moreover, a class I recommendation remains to perform DT during the implantation of subcutaneous ICD (S-ICD). The aim of the present survey was to analyze the current practice of DT during T-ICD and S-ICD implantations in Italy.

Methods

In March 2021, an ad hoc questionnaire on the current performance of DT and the standard practice adopted during testing was completed by 72 operators at Italian centers implanting S-ICD and T-ICD.

Results

48 (67%) operators reported never performing DT during de-novo T-ICD implantations, while no operators perform it systematically. The remaining respondents perform it in specific cases: right sided implantations (54%), poor signal sensing (46%), secondary prevention patients (42%), arrhythmic syndromes (13%), hypertrophic cardiomyopathy (8%). DT is never performed at T-ICD generator change. At the time of de-novo S-ICD implantation, DT is never performed by 9 (13%) operators and performed systematically by 48 (66%). The remaining operators perform DT in cases of: secondary prevention patients (73%), sub-optimal S-ICD placement (33%), non-compromised ejection fraction (33%) or obese patients (7%). DT is not performed at S-ICD generator change by 92% of operators. DT is conducted by delivering a first shock energy of 65J by 60% of operators, while the remaining 40% test lower energy values. The most frequently reported conditions for revising the system at the end of de- novo implantation procedure is high shock impedance (54%) and sub-optimal S-ICD placement or high PRAETORIAN score (50%). With adequately low shock impedance and optimal system placement, 37% of operators would accept a defibrillation margin &lt;15J.

Conclusion

In current clinical practice, the vast majority of operators omit DT at T-ICD implantation, even when still recommended in the guidelines. DT is also frequently omitted at S-ICD implantation. We also report a wide variability among operators in the procedures followed during DT and in the criteria applied for defining the procedural success.

Funding Acknowledgement

Type of funding sources: None.

Safety of omitting defibrillation efficacy testing with subcutaneous defibrillators: a propensity matched case-control study

Funding Acknowledgements

Type of funding sources: None.

Background

Defibrillation efficacy testing (DT) is recommended at implantation of subcutaneous implantable cardioverter–defibrillators (S-ICD). However, prior works found that adherence to this recommendation is declining in clinical practice.

Purpose

To compare survival from all-cause death and first ineffective shock (primary endpoint) and the composite of all-cause death, ineffective shock, inappropriate shock and device-related complication (secondary endpoint) between patients who underwent DT and those with omitted DT.

Methods

We analyzed 1652 consecutive patients who underwent S-ICD implantation in 60 Italian centers from 2013 to 2019.

Results

DT was not performed in 325 (20%) patients (no-DT patients). As compared with the DT group, these patients were older (51 ± 16 vs. 48 ± 15 years; p &lt; 0.01) and had lower ejection fraction (37 ± 16% vs. 46 ± 16%; p &lt; 0.01). The 325 no-DT patients were propensity matched with 325 patients of the DT group. During a median follow up of 19 months, 27 (4.2%) patients died for any-cause. During follow-up, 34 (5.2%) patients received appropriate shocks to treat discrete episodes of VT/VF. The first shock was effective in 30 out of 34 patients (88%), whereas a second shock was required to terminate VT/VF in 3 patients and a third shock in the last one. The primary endpoint occurred in 31 (4.8%) patients, and the risk was not significantly increased in the no-DT cohort (HR = 1.26, 95%CI:0.62-2.55, p = 0.522). Inappropriate shocks were reported in 36 (5.5%) patients and device-related complications in 25 (3.8%) patients during follow-up. Survival from the composite secondary endpoint was comparable between groups (HR = 0.86, 95%CI:0.57-1.32, p = 0.500).

Conclusions

Our data confirmed that DT is frequently omitted in current clinical practice, especially in older patients with worse systolic function. A strategy that omits DT did not appear to compromise the effectiveness of the S-ICD and no additional risk seems associated with DT omission at a mid-term follow-up. These data suggest that routine DT at S-ICD implant might not be necessary. Randomized trials are needed to confirm this finding.

P521Conversion test during Subcutaneous Implantable Cardioverter-Defibrillator Implantation in clinical practice: in-hospital and mid-term outcome

Funding Acknowledgements

No funding

OnBehalf

RHYTHM DETECT Registry

Background

With subcutaneous implantable cardioverter–defibrillators (S-ICD), conversion test (CT) is still recommended at implantation. However, prior works found that adherence to this recommendation is declining in clinical practice.

Purpose

To describe current practice regarding CT at S-ICD implantation, and also measure in-hospital outcome of patients who underwent CT and mid-term outcome of patients without CT.

Methods

We analyzed 1652 consecutive patients (49 ± 15 years old, 80% male, 51% with ischemic or non-ischemic dilated cardiomyopathy, 45% with ejection fraction ≤35%) who underwent S-ICD implantation in 60 Italian centers from 2013 to 2019.

Results

CT data were missing in 27 patients. CT was performed in 1300 patients. Successful conversion with ≤65J was obtained in 97.4% of patients. Shock at 80J was not effective in 12 (0.9%) patients. In 10 of these patients the CT was successful after device repositioning, while in 2 patients it was decided to implant a transvenous ICD. Two (0.15%) episodes of electromechanical dissociation (1 fatal) were reported as consequence of CT. CT was not performed in 325 patients (for clinical reasons in 182 patients, for facility preference in 71, ventricular fibrillation not inducible in 72 patients). As compared to the CT group, these patients were older (51 ± 16 vs. 48 ± 15 years; p &lt; 0.01) and had lower ejection fraction (37 ± 16% vs. 46 ± 16%; p &lt; 0.01). 243 non-CT patients had at least 6 months follow-up (median 15 months). In this group, 12 (4.9%) patients had appropriate shocks to treat VT/VF (all successfully terminated with the first shock), and 9 (3.7%) patients had inappropriate shocks.

Conclusions

This analysis showed that CT is frequently omitted in current clinical practice, especially in older patients with worse systolic function. Shocks at CT are very frequently effective and system revision after CT is rarely required. CT is also safe, although serious adverse events cannot be excluded. A strategy that omits CT did not appear to compromise the effectiveness of the S-ICD, but larger populations and longer follow-up are needed to confirm this finding.

Glycemic Control Maintained over Time and Joint Stiffness in Young Type 1 Patients: What Is the Mathematical Relationship?

BACKGROUND

It is widely known that diabetes can induce stiffness and adversely affect joint mobility even in young patients with type 1 diabetes mellitus (T1D). The aim of this study was to identify a mathematical model of diabetes mellitus long-term effects on young T1D patients.

METHODS

Ankle joint mobility (AJM) was evaluated using an inclinometer in 48 patients and 146 healthy, sex- BMI-, and age-matched controls. Assuming time invariance and linear superposition of the effects of hyperglycemia, the influence of T1D on AJM was formalized as an impulse response putting into relationship past supernormal HbA1c concentrations with the ankle total range of motion. The proposed model was identified by means of a nonlinear evolutionary optimization algorithm.

RESULTS

AJM was significantly reduced in young T1D patients (P < .001). AJM in both plantar and dorsiflexion was significantly lower in subjects with diabetes than in controls (P < .001). The identified impulse response indicates that impaired metabolic control requires 3 months to bring out its maximum effect on the reduction of AJM, while the following long-lasting decay phase with the expected AJM recovery times, normally depends on the slow turnover of collagen. HbA1c concentration levels above 7.2% are sufficient to produce a reduction of ankle ROM.

CONCLUSIONS

In young patients with T1D the lack of glycemic control over time affects AJM. HbA1c levels can serve as a relevant prognostic factor for assessing the progression of LJM in subjects with diabetes.

Assessment of cutaneous microcirculation by laser Doppler flowmetry in type 1 diabetes

BACKGROUND

The burden of type 1 diabetes (T1D) is growing worldwide, stressing the requirement to limit the threat of its long-term complications. In this regard, the development of methods for the early diagnosis and non-invasive monitoring of vascular abnormalities is widely recognized as one of the greatest priorities of the clinical research in this field.

OBJECTIVE

To assess the deterioration of physiological properties extracted from laser Doppler flowmetry (LDF) signals of microvascular perfusion and, secondly, to investigate their association with the quality of long-term metabolic control.

METHODS

Microvascular perfusion was recorded at the hallux of 63 control subjects and 47 T1D patients, whose glycaemic control was characterized in terms of the annual average levels of glycosylated haemoglobin (HbA1c). Pulse Decomposition Analysis was applied to the LDF data, in order to derive non-invasive markers of vascular stiffness based on a multi-Gaussian representation of the peripheral pulse waveforms; furthermore, wavelet transform analysis was used to evaluate the microvascular myogenic vasomotion and, finally, a physiological model of the reactive hyperaemia to a local thermal stimulus at 43 was used to test the integrity of the neurovascular pathways.

RESULTS

Compared to the control group, T1D patients showed a lower microvascular perfusion at baseline, and a larger vasodilatory reserve upon local heating, but no significant difference in myogenic activity. Moreover, the results of the PDA carried out on the LDF pulse waves, indicate the presence of a significant strong relation between large artery stiffness and the overall loss of glycaemic control over the past year.

Continuous Movement Monitoring of Daily Living Activities for Prevention of Diabetic Foot Ulcer: A Review of Literature

Lower extremity ulcers represent the most ominous, feared, and costly complications of diabetes mellitus. The aim of this review is to highlight the role of daily life physical activities (PAs) and continuous movement monitoring (CMM) in the prevention of foot ulcers. Peripheral neuropathy and peripheral vascular disease are the main causes of foot ulceration and contribute, in turn, to the development of additional risk factors such as foot deformities and/or joint and muscular alterations. Moreover, a deficit of balance, posture abnormalities, followed by gait alterations, increases the risk of ulceration. PA can play a key role in the management of patients with diabetes and in the prevention of ulcers; however, even if it has been reported that some of these risk factors significantly improve after a few weeks of exercise therapy (ET), the real preventive role of ET has not yet been demonstrated. These uncertain results can occur due to some limitations in the management of the same relationship between PA and diabetic foot prevention. Technological advances during the last years enable timely management of overall daily PA. The use of these modern technologies and devices allows CMM assessment and description of daily PA even in the long term. The data collected from these devices can be used to properly manage patients' PA and thus contribute to the prevention of foot ulcers.

Type 1 diabetes, sport practiced, and ankle joint mobility in young patients: What is the relationship?

BACKGROUND/OBJECTIVE

It is known that patients with diabetes can develop limited joint mobility (LJM) and that this can depend on the metabolic control maintained and the duration of the disease. The aims of this study were to verify the presence of ankle joint mobility (AJM) deficits in both plantar and dorsiflexion in young type 1 diabetic patients (T1D) considering also the possible role of sport practiced as a further factor, able to modify AJM.

METHODS

AJM was evaluated by an inclinometer in 82 T1D patients (M/F: 48/34), mean age 12.9 ± 2.6 years, body mass index (BMI) 19.7 ± 3.6 kg/m² , duration of diabetes 5.6 ± 3.3 years, mean HbA1c 7.5 ± 1.0% and in 226 healthy controls (M/F: 146/80), age-, gender-, and BMI-matched practicing different sports (soccer, volleyball, basketball, and dance).

RESULTS

The patients' ankle range of motion was significantly lower than that in controls (132.7 ± 22.3° vs 126.1 ± 17.9°; P < .017). In particular, ankle plantar flexion was significantly lower in the patients group (31.6° ± 7.9° vs 28.5° ± 6.6°; P < .002). Soccer players showed lower AJM in both groups: patients (120.1 ± 15.9° vs 127.3 ± 18.1) and controls (119.4 ± 21.1° vs 142.0 ± 18.1; P < .0001) than subjects practicing other sports or who were sedentary. In both groups, patients and controls, age, sex, duration of disease, hemoglobin 1Ac, and BMI have not been shown to be correlated to the mobility assessed.

CONCLUSIONS

The results of this study, in addition to confirming the negative effect of diabetes on AJM of young T1D patients, suggest that during these evaluations the sport-related effect should be considered because it can induce significant changes of AJM.

History, Prevalence and Assessment of Limited Joint Mobility, from Stiff Hand Syndrome to Diabetic Foot Ulcer Prevention: A Narrative Review of the Literature

BACKGROUND

Limited Joint Mobility (LJM) is a dreaded complication of Diabetes Mellitus (DM). During the last half century, LJM has been studied in patients of different age because it has been considered useful for the monitoring of a patient's condition and for the prevention of vascular disease and diabetic foot.

OBJECTIVES

The main aims of this review are to describe the relationship between DM and joint mobility as well as its prevalence and assessment. We have also investigated the role of LJM in the development of diabetic foot ulcers.

METHODOLOGY

An in-depth literature search was conducted to identify studies that examined the prevalence and characteristics of LJM in patients with DM of different types, age, durations and chronic complications.

RESULTS

Many factors (therapy improvements, population characteristics and different evaluation methods) concur to hinder an exact assessment of the prevalence of LJM. However, it has been confirmed that LJM is widespread among patients with DM and may affect more than two-thirds of them in addition to being a major risk factor for foot ulcer. Its role in the monitoring of a patient's condition is also important for the definition of risk thresholds such as in patients with diabetic foot. The efficacy of exercise therapy for the treatment of LJM, also in patients at risk of foot ulcer, has not been discussed.

CONCLUSION

Difficulties encountered in the definition of the prevalence of LJM may hinder its study and the establishment of preventive interventions. However, LJM plays a key role in the monitoring of patients, especially those at risk for ulcer.

Tapentadol Prolonged Release Reduces the Severe Chronic Ischaemic Pain and Improves the Quality of Life in Patients with Type 2 Diabetes

This study has been performed in diabetic type 2 patients with pain due to peripheral artery disease (PAD) in order to evaluate the efficacy and tolerability of tapentadol prolonged release (PR). Methods. 25 patients with type 2 diabetes (13 F and 12 M) were admitted in the study. The evaluation of the analgesic efficacy of tapentadol PR was based on both the assessment of the intensity of the pain (NRS scale from 0 to 10) and the nature of the pain (DN4 questionnaire) and on assessment of the patient's quality of life and state of health (SF-12 Health Survey). Study duration was 3 months: a baseline visit and follow-up included visits after 1 week, 1 month, 2 months, and 3 months. Results. At the beginning of the study, the mean intensity of the pain was 7.88 ± 1.17 on the NRS scale and at visit 2 it reduced in a statistically significant way; at the end of the treatment with tapentadol PR, the mean intensity was 2.84 points on the NRS scale. Conclusion. In type 2 diabetic patients with chronic severe pain due to PAD, tapentadol PR reduced pain intensity, improving the quality of life.

Hospitalization for Charcot neuroarthropathy in diabetes: A population study in Italy

AIMS

To provide data on hospitalization and incidence rates of Charcot neuroarthropathy (CN) and its relation to lower limbs' amputations/revascularizations in population with diabetes of Italy as well as of one of its regions (Tuscany).

METHODS

Hospitalizations with CN diagnosis (codes ICD-9-CM: 7130, 7135, 7138) have been recorded in people with diabetes over years 2003-2013 in Italy and 2008-2015 in Tuscany. Amputations, peripheral vascular disease, revascularizations and infections were likewise evaluated.

RESULTS

Between 2003 and 2013 CN hospitalizations were very infrequent in Italy ranging between 14×100,000 and 11×100,000 patients with diabetes. In Tuscany they declined to a minimum of 7×100,000 patients in 2015, after a previous increase to a maximum of 22×100,000 (p=NS for both). Yearly CN incidence remained constant in Italy, declining in Tuscany to a minimum of 3.4×100,000 diabetic patients in 2015 (p=0.047). CN patients were younger and with longer length of hospital stay than those with non-Charcot diabetic foot (p<0.05 for both). Amputation and infection rates were manifold higher in CN patients than in those with non-Charcot diabetic foot, while the revascularization rate was similar in both.

CONCLUSIONS

Over last decade, in Italy and Tuscany yearly CN incidence and hospitalization rates concerned only a small percentage of patients, remaining constant over years and declining in Tuscany in the last couple of years. CN was significantly associated to younger age, longer hospital stay and greater risk of amputations and infections while the need of revascularization was similar to that of non-Charcot diabetic foot.

The role of joint mobility in evaluating and monitoring the risk of diabetic foot ulcer

AIMS

Evaluation of how ankle joint mobility (AJM) can be useful in the identification of patients with diabetes at risk of foot ulcer (FU).

METHODS

Plantar and dorsal flexion of foot were evaluated using an inclinometer in 87 patients (54 type 2 and 33 type 1), and 35 healthy sex- and age-matched control subjects. Patients with diabetes were followed up for diagnosis of FU over the next 8 years and subsequently, patients were subdivided into: those without a history of FU (18 type 1 and 33 type 2), those who had a history of FU detected before baseline evaluation (14 type 2) and those who had history of first ulceration detected by the 8th year of the evaluation period (7 type 2).

RESULTS

Aging and diabetes caused a significant reduction in mobility of each of the movements investigated (p<0.001), whereas after adjusting for the confounding effect of age, diabetes specifically reduced plantar flexion (p<0.0001). AJM was significantly lower in those with history of previous FU compared to all the other groups (p<0.001). The first ulceration was detected in the same foot presenting lower AJM in 17 of the 22 subjects with diabetes with history of ulcer (77.27%).

CONCLUSIONS

Diabetes and aging reduce AJM although diabetes seems to reduce plantar flexion to a more specific extent. Reduced AJM is mostly associated with a previous history of FU. The evaluation of AJM is a valid and reliable ulcer risk scale that indicates which foot is at higher ulcer risk.

Diabetic foot prevention: the role of exercise therapy in the treatment of limited joint mobility, muscle weakness and reduced gait speed

OBJECTIVE

It is well known that limited joint mobility of the ankle and foot level, impaired muscular performance and reduced gait speed are risk factors for ulceration in diabetic foot. The aim of this study was to evaluate the effect of an experimental protocol of exercise therapy on joint mobility, muscular strength and gait speed in a group of long-term diabetic subjects.

METHODS

The protocol consisted of a 12-week supervised training program; both joint mobility and muscular strength at the ankle were measured before and after exercise therapy respectively by an inclinometer and isometric dynamometers in 26 diabetic subjects and compared to 17 healthy controls.

RESULTS

Ankle joint mobility of plantar flexion was reduced about 36% and dorsal flexion by about 23% in diabetic subjects compared to controls (p < 0.001), but significantly increased after exercise therapy (p < 0.001 for both). Ankle muscular strength in plantar flexion was reduced by about 51% and in dorsal flexion by 30% in diabetic patients compared to controls, but these also significantly increased after exercise therapy (p < 0.001). Consequently, patients' walking speed increased after exercise therapy by 0.28 m/s (p < 0.001).

CONCLUSION

A 12-week supervised program of exercise therapy significantly improves joint mobility, muscular performance and walking speed in diabetic patients--thus limiting one of the pathogenic factors of diabetic foot and potentially preventing disability.

Diabetic foot and exercise therapy: step by step the role of rigid posture and biomechanics treatment

Lower extremity ulcers represent a serious and costly complication of diabetes mellitus. Many factors contribute to the development of diabetic foot. Peripheral neuropathy and peripheral vascular disease are the main causes of foot ulceration and contribute in turn to the growth of additional risk factors such as limited joint mobility, muscular alterations and foot deformities. Moreover, a deficit of balance, posture and biomechanics can be present, in particular in patients at high risk for ulceration. The result of this process may be the development of a vicious cycle which leads to abnormal distribution of the foot's plantar pressures in static and dynamic postural conditions. This review shows that some of these risk factors significantly improve after a few weeks of exercise therapy (ET) intervention. Accordingly it has been suggested that ET can be an important weapon in the prevention of foot ulcer. The aim of ET can relate to one or more alterations typically found in diabetic patients, although greater attention should be paid to the evaluation and possible correction of body balance, rigid posture and biomechanics. Some of the most important limitations of ET are difficult access to therapy, patient compliance and the transitoriness of the results if the training stops. Many proposals have been made to overcome such limitations. In particular, it is important that specialized centers offer the opportunity to participate in ET and during the treatment the team should work to change the patient's lifestyle by improving the execution of appropriate daily physical activity.

Lack of Influence of the Androgen Receptor Gene CAG-Repeat Polymorphism on Clinical and Electrocardiographic Manifestations of the Brugada Syndrome in Man

Background

Clinical studies suggest that testosterone (T) plays an important role in the male predominance of the clinical manifestations of the Brugada syndrome (BS). However, no statistically significant correlations have been observed between T levels and electrocardiogram (ECG) parameters in the BS patients. We investigated whether the hormonal pattern and the variation within CAG repeat polymorphism in exon 1 of the androgen receptor (AR) gene, affecting androgen sensitivity, are associated with the Brugada ECG phenotype in males.

Methods and Results

16 male patients with BS (mean age 45.06 ± 11.3 years) were studied. 12-lead ECG was recorded. Blood levels of follicle-stimulating hormone, luteinizing hormone, prolactin, testosterone, free-T, dihydrotestosterone, 17-β-estradiol, estrone, 3-alpha-androstanediol-glucuronide, delta-4-androstenedione, dehydroepiandrosterone sulphate, progesterone, 17-hydroxyprogesterone, and sex hormone binding globulin were assayed. Genotyping of CAG repeats on DNA extracted from leukocytes was carried out. No relationship was found between hormone values and ECG parameters of BS. BS patients showed the CAG length normally recognized in the human polymorphism range and the number of CAG repeats did not correlate with the ECG pattern of BS.

Conclusions

The AR CAG repeat length does not correlate with the ECG features of the patients affected by BS. The search for genes downstream AR activation as possibly responsible for the increased risk of spontaneous arrhythmias in BS males after puberty is warranted.

Analysis of the chaotic component of the sinusal R-R intervals as a tool for detecting a silent cardiac dysautonomia in type 2 diabetes mellitus

This study explores the heart rate (HR) variability (V) in order to detect whether the chaotic component of the sinusal R-R intervals (SRRI) can be interpreted as an early indicator of a silent cardiac neurovegetative dysautonomia in apparently uncomplicated Type 2 diabetic patients (DP). The SRRI were provided by the 24-h Holter ECG of 10 Type 2 DP (5 M and 5 F, mean age = 41 +/- 5 years). Control data were obtained by the 24-h Holter ECG of 10 clinically healthy subjects (CHS, 5 M and 5 F, mean age = 38 +/- 6 years). The chaotic component of HRV was investigated via the correlation dimension (CD) analysis (A) of the SRRI, performed per each hour of the ECG recording. The hourly-qualified series of SRRI, HR and CD index (I) were, in turn, analyzed via methods of conventional statistics and chronobiology, the latter ones for assessing the circadian rhythm (CR). The CDI CR was found to peak during the night in CHS, and to be unphysiologically rotated to the diurnal hours of the day in Type 2 DP. The diurnal inversion of the CDI CR in Type 2 DP suggests that the chaotic component of HRV shows an abnormal rhythnic pattern over the day-night period. Considering that the investigated Type 2 DP were lacking of documentable signs of cardiac neuropathy, it is hypothesized that the diurnal phase of shift CDI CR might be a potential indicator of a silent autonomic cardiac dysfunction in Type 2 DP. Such a hypothesis waits for further confirmations.

Idiopathic dilated cardiomyopathy associated with coeliac disease: the effect of a gluten-free diet on cardiac performance

An increased incidence of coeliac disease has recently been reported in patients with idiopathic dilated cardiomyopathy. This report deals with three patients with idiopathic dilated cardiomyopathy and coeliac disease who underwent clinical and laboratory evaluation to establish the effect of a gluten-free diet on cardiac performance. Two patients observed the gluten-free diet regimen very strictly, and, after a 28-month follow-up period, showed an improvement in echocardiographic parameters as well as in cardiological features and quality of life, as evaluated by the Minnesota Living with Heart Failure questionnaire and the Gastrointestinal Symptom Rating Scale questionnaire. The third patient did not observe the gluten-free diet and presented a worsening in the echocardiographic parameters and cardiological symptoms which required supplementary drug therapy. These preliminary data appear to suggest that the gluten-free diet may have a beneficial effect on cardiac performance in patients with idiopathic dilated cardiomyopathy.

[Circadian periodicity in human heart rate daily variability disorders: subsequent demonstrations through a chronobiological approach to the values of estimated alpha exponent on sinusal R-R intervals]

OBJECTIVE

The present study is aimed at giving a further demonstration that the disorder in human heart rate variability is characterized by a circadian periodicity. Such an evidence has been provided by estimating the alpha exponent of the Lévy's stable distribution approximated to the histogram of the differences between the durations of two adjacent sinusal R-R intervals.

MATERIALS AND METHODS

The purpose has been pursued by estimating the alpha exponent on fragments of one hour of the Holter electrocardiogram executed in 10 clinically healthy subjects (5 males and 5 females, ranging in age from 23 to 30 years).

RESULTS

The chronobiological analysis of the hourly-qualified values of the alpha exponent has demonstrated a significant circadian rhythm for this coefficient.

CONCLUSIONS

The significant circadian periodicity of the alpha exponent is a further evidence that the disorder in human heart rate variability, herein represented by the extreme variability of the differences between the durations of two consecutive sinusal R-R intervals, is characterized by a periodic recursivity.

Postmortal decay of acetylcholine levels in the spinal cord of rat, chicken and frog

The decay of acetylcholine (ACh) after death of an animal has been estimated in the cervical spinal cord of rat, chicken and frog. The level of ACh in the frog (19.90 nmol/g wet weight) shows no variation from 20 to 500 s after death. In the rat and chicken, there is a decrease in the first 100 s after death to lower values; 4.35 nmol/g wet weight in the rat and 4.60 nmol/g wet weight in the chicken. The levels of ACh in the cervical spinal cord of the rat an chicken at the time of death were estimated by extrapolation to time 0 of the curve of the decay of ACh in the first 100 s. The values obtained were: 121.64 nmol/g wet weight in the chicken and 34.19 nmol/g wet weight in the rat.