Respiration is a fundamental vital sign and an established marker of disease severity and mortality risk, particularly in patients with cardiovascular disease. Despite its prognostic significance, respiratory monitoring remains underused in routine clinical practice and remote telemonitoring. At the same time, advances in biosignal processing enable robust extraction of respiratory information from the ubiquitous electrocardiogram, allowing respiratory assessment without additional sensors. This review highlights respiration as an underused biosignal in cardiovascular medicine and summarizes physiological principles and technical approaches for electrocardiogram-derived respiration, including respiratory sinus arrhythmia, respiration-related QRS amplitude modulations, and electrical axis shifts. It emphasizes the potential of electrocardiogram-derived respiration-especially nocturnal respiratory rate-in cardiac patients to enhance risk stratification and guide clinical decision-making, including patient selection for implantable cardioverter-defibrillator therapy. The feasibility of integrating nocturnal respiratory rate monitoring into standard surveillance of cardiac patients is discussed, alongside emerging evidence that this marker may identify patients with limited benefit from prophylactic implantable cardioverter-defibrillator therapy. The technical possibility to derive respiration from routine electrocardiographic recordings represents a significant yet under-utilized opportunity. Electrocardiogram-derived respiratory rate is a promising scalable non-invasive biomarker for individualized risk stratification and may complement conventional indicators such as left-ventricular ejection fraction. Large-scale prospective randomized trials are now needed to establish whether incorporating electrocardiogram-derived respiratory markers into routine practice can improve patient outcomes and optimize therapy allocation.

ObjectiveThe aim of the study was to derive median age- and sex-specific respiratory rates in a population-based sample of adults and to identify disease and lifestyle factors associated with elevated respiratory rates.MethodsIn the population-based KORA FF4 study conducted in Augsburg, Germany, 5-minute 12-lead resting electrocardiograms (ECGpro-system, AMEDTEC) were recorded in 2,224 participants from 39 to 88 years. Respiratory rate was derived from these electrocardiograms. Sex- and age-specific medians, IQRs, and percentiles were calculated. Associations of sociodemographic, disease, and lifestyle variables with elevated resting respiratory rate were assessed by univariable and multivariable logistic regression analyses.ResultsRespiratory rate decreased slightly from youngest to middle-aged women and men and increased in old age. Overall, median (IQR) was 15.80 (3.16) breaths per minute (brpm). Five percent of the participants had values lower than 12.06 brpm, and five percent had values above 20.06 brpm (95th percentile). Elevated respiratory rates of ≥ 18.6 brpm were found in 13.8% (n = 308). In an adjusted logistic regression model, age, abdominal obesity, diabetes, COPD, smoking, and low education were significantly associated with elevated respiratory rate. Stratified analyses showed that education appeared to be more relevant in women, while the effect of diabetes was more pronounced in men.ConclusionsHigh respiratory rate may be an indicator of impaired health in the general population, especially regarding pulmonary and metabolic characteristics, and unfavorable lifestyle and living conditions. Individuals with an increased respiratory rate should therefore be examined and followed up more closely to recognize diseases and adverse progressions at an early stage and to possibly prevent them.

Reduced respiratory sinus arrhythmia, quantified as expiration-triggered sinus arrhythmia (ETA) from simultaneous electrocardiogram and respiration recordings, is a strong long-term mortality predictor in myocardial infarction survivors. Here, we investigated whether ETA also predicts mortality risk in the general elderly population. ETA was quantified from 30-min electrocardiogram and respiration recordings in 1788 general population subjects aged ≥60 years, who were then followed for a median of 4.0 years (median age 72 years, 58% female). Four-year all-cause mortality was 4.6%. Abnormal ETA using a predefined cutoff (≤0.19 ms) was associated with a 4-year mortality of 6.9%, compared to 3.7% in the remaining participants (p = 0.0022). ETA remained a significant mortality predictor in multivariable Cox analysis, also considering a modified Framingham score incorporating sex, age, smoking, cholesterol, blood pressure, antihypertensive medication, family history, diabetes and clinical atherosclerosis (multivariable hazard ratio 1.81; 95% confidence interval 1.17–2.81; p = 0.008). Combined risk prediction by ETA (using an optimized cutoff of ≤0.86 ms) and the Framingham score stratified patients into a low-risk (both parameters normal), an intermediate-risk (one parameter abnormal) and a high-risk group (both parameters abnormal), with 4-year mortality rates of 1.9%, 4.4% and 10.1%, respectively. We conclude that in elderly general population subjects, ETA is a mortality risk predictor that complements classical clinical risk stratification.

Introduction: Digital technologies, such as telemedicine and wearable devices, are transforming health care by enhancing cross-sectoral care and targeted health responses. Despite these advancements, challenges such as data protection, lack of interoperability, reimbursement, and financial costs hinder telemedicine's broader implementation, especially within the German health care system. This study explores the use, acceptance, and barriers of telemedicine among cardiologists, internists, and general practitioners in Germany. Methods: A web-based survey was conducted from October 2023 to January 2024, targeting cardiologists, internists, and general practitioners. The survey assessed current telemedicine usage, acceptance, and barriers. Data analysis included descriptive statistics and exploratory cluster analysis. Results: Of the 172 physicians analyzed, 76.2% were cardiologists. Telemonitoring (45.9%) and wearable devices (26.2%) were the most used telemedicine applications, whereas video consultations (11.0%) and apps (19.2%) were less common. Despite high costs (57.7%), insufficient technical expertise (20.8%), and lack of system interoperability (45.8%), respondents rated telemedicine positively and saw several chances and potentials. Cluster analysis identified four user groups: The pioneers, the focused practitioners, the using skeptics, and the uninformed distanced, each with unique needs and challenges. Discussion: The acceptance of elemedicine among physicians indicates recognition of its benefits for patient care. Only half of the respondents felt reasonably well informed about telemedicine. Overall, our study shows the current use of telemedicine as well as the acceptance, barriers, and challenges perceived in the German ambulatory sector. It underlines the increasing importance of telemedicine for patient care and highlights existing barriers to enable wider implementation in the outpatient sector. The results show that telemedicine in Germany is on a promising path. The biggest obstacles still appear to be reimbursement and the technical infrastructure.

AimsEfficient use of preventive cardiac therapies is often limited by inefficient risk prediction, calling for new prediction tools. Ventricular premature complexes (VPCs) elicit electrocardiographic changes in the repolarization of the first post-extrasystolic normal beat. The aim of this study was to assess whether this post-extrasystolic ST segment and T wave variation (PEST) conveys prognostic information regarding the mortality risk of cardiac patients.MethodsPEST was calculated from 30-min ECGs obtained from 941 survivors of acute myocardial infarction (AMI) as mean difference between the sum of squared voltages from three orthogonal leads (XYZ) of the first (post-extrasystolic) and second (reference) beat after each VPC, in a time window between the limits ϕ1 and ϕ2. Optimal limits yielding a maximum area under the receiver-operating characteristics (ROC) curve were determined by systematic testing, covering the time window from the J point to the end of the T wave. A strong association was found with ϕ1/ϕ2 encompassing 40–230 ms after the J point, which was used to calculate PEST in the analysis. Kaplan-Meier curves and univariable/multivariable Cox proportional hazards models were used to study mortality prediction by PEST. The findings were validated in an independent cohort of 1.788 general population subjects aged 60 years or older.ResultsThe area under the ROC curve for PEST was 0.72, with an optimum cutoff at ≤ −6.69 mV2. The 88 patients with PEST values below this cutoff had a considerably higher mortality than the remainder of the patients (25% vs. 5.8%, p < 0.0001; univariable hazard ratio 4.7, 95% CI 2.4–12.0, p < 0.001). In a multivariable Cox regression analysis considering left-ventricular ejection fraction, presence of diabetes mellitus, and Global Registry of Acute Coronary Events (GRACE) score, PEST remained significantly associated with mortality (hazard ratio 3.6, 95% CI 1.9–6.9, p < 0.0001). In the validation cohort, abnormal PEST was also associated with significantly increased 4-year mortality (11.9% vs. 4.3%, p = 0.00095).ConclusionPEST is a strong independent predictor of all-cause mortality in AMI survivors and elderly subjects from the general population. While the pathophysiology of this association remains to be investigated, PEST may complement current risk prediction tools in various clinical settings.

This study aims to explore the implementation steps, challenges, and optimization strategies for telemonitoring in the management of patients with heart failure, a method that holds promise for improving clinical outcomes and reducing healthcare system burdens. A mixed-methods approach was employed, comprising semi-structured interviews with international physicians and an online survey conducted with German telemedicine centers. The research focused on the examination of patient flow processes and identifying barriers to effective telemonitoring, particularly in organizational structures and patient engagement. The findings outline clear phases of patient flow in telemonitoring and reveal significant challenges, especially concerning patient involvement and operational management. Key areas for improvement were identified, including workflow standardization, optimization of resource allocation, and process efficiency enhancements. Addressing the outlined challenges and leveraging technological advancements can make telemonitoring a vital component of heart failure management. This approach could lead to reduced hospital readmissions, enhanced clinical outcomes, and significant improvements in patients’ quality of life.

BACKGROUND:Despite advances in coronary revascularization and in heart failure management, myocardial infarction survivors remain at substantially increased mortality risk. Precise risk assessment and risk-adapted follow-up care are crucial to improve their outcomes. Recently, the fragmented QRS complex, i.e. the presence of additional spikes within the QRS complexes on a 12-lead electrocardiogram, has been discussed as a potential non-invasive risk predictor in cardiac patients. HYPOTHESIS:The aim of this study was to evaluate the prognostic meaning of the fragmented QRS complex in myocardial infarction survivors. METHODS:609 patients with narrow QRS complexes <120 ms were included in a prospective cohort study while hospitalized for myocardial infarction and followed for 5 years. RESULTS:The prevalence of the fragmented QRS complex in these patients amounted to 46.8% (285 patients). These patients had no increased hazard of all-cause death (HR 0.84, 95%-CI 0.45-1.57, p = 0.582) with a mortality rate of 6.0% compared to 7.1% in patients without QRS fragmentations. Furthermore, the risks of cardiac death (HR 1.28, 95%-CI 0.49-3.31, p = 0.613) and of non-cardiac death (HR 0.6, 95%-CI 0.26-1.43, p = 0.25) were not significantly different in patients with QRS fragmentations. However, patients with QRS fragmentations had increased serum creatine kinase concentrations (1438U/l vs. 1160U/l, p = 0.039) and reduced left ventricular ejection fractions (52% vs. 54%, p = 0.011). CONCLUSIONS:The hypothesis that QRS fragmentation might be a prognostic parameter in survivors of myocardial infarction was not confirmed. But those with QRS fragmentation had larger myocardial infarctions, as measured by creatine kinase and left ventricular ejection fraction.

BACKGROUND:While there is substantial evidence on the impact of prehospital resuscitation efforts on survival after out-of-hospital cardiac arrest (OHCA), the importance of the first electrocardiogram after return of spontaneous circulation has been much less studied. OBJECTIVES:The aim of this study was to identify prognostically relevant electrocardiographic findings in patients after OHCA due to myocardial infarction (MI). METHODS:A total of 119 patients admitted to hospital after suffering an OHCA due to MI were retrospectively analyzed. Patient characteristics and the first 12-lead electrocardiogram after return of spontaneous circulation were collected. The primary outcome was 30-day mortality. RESULTS:A number of electrocardiographic findings were significantly associated with 30-day mortality: atrial fibrillation/flutter (HR 2.29 [95% CI 1.17-4.49, p = 0.015]), right bundle branch block (HR 2.23 [95% CI 1.14-4.56, p = 0.020]), bifascicular block (HR 2.51 [95% CI 1.04-6.059, p = 0.040]), T inversion (HR 2.01 [95% CI 1.02-3.99, p = 0.043]), QTc duration ≥500 ms (HR 2.21 [95% CI 1.10-4.42, p = 0.025]) and QT dispersion ≥ 100 ms (HR 2.11 [95% CI 1.02-4.37, p = 0.045]). CONCLUSION:Several different electrocardiographic findings are associated with increased mortality in patients with OHCA due to MI.

Background and Aims Risk stratification of sudden cardiac death after myocardial infarction and prevention by defibrillator rely on left ventricular ejection fraction (LVEF). Improved risk stratification across the whole LVEF range is required for decision-making on defibrillator implantation. Methods The analysis pooled 20 data sets with 140 204 post-myocardial infarction patients containing information on demographics, medical history, clinical characteristics, biomarkers, electrocardiography, echocardiography, and cardiac magnetic resonance imaging. Separate analyses were performed in patients (i) carrying a primary prevention cardioverter-defibrillator with LVEF <= 35% [implantable cardioverter-defibrillator (ICD) patients], (ii) without cardioverter-defibrillator with LVEF <= 35% (non-ICD patients <= 35%), and (iii) without cardioverter-defibrillator with LVEF > 35% (non-ICD patients >35%). Primary outcome was sudden cardiac death or, in defibrillator carriers, appropriate defibrillator therapy. Using a competing risk framework and systematic internal-external cross-validation, a model using LVEF only, a multivariable flexible parametric survival model, and a multivariable random forest survival model were developed and externally validated. Predictive performance was assessed by random effect meta-analysis. Results There were 1326 primary outcomes in 7543 ICD patients, 1193 in 25 058 non-ICD patients <= 35%, and 1567 in 107 603 non-ICD patients >35% during mean follow-up of 30.0, 46.5, and 57.6 months, respectively. In these three subgroups, LVEF poorly predicted sudden cardiac death (c-statistics between 0.50 and 0.56). Considering additional parameters did not improve calibration and discrimination, and model generalizability was poor. Conclusions More accurate risk stratification for sudden cardiac death and identification of low-risk individuals with severely reduced LVEF or of high-risk individuals with preserved LVEF was not feasible, neither using LVEF nor using other predictors.

AbstractIn contemporary healthcare, effective risk stratification in the general population is vital amidst rising chronic disease rates and an ageing demographic. Deceleration Capacity of the heart rate (DC), derived from 24-hour Holter electrocardiograms, holds promise in risk stratification for cardiac patients. However, the potential of short-term electrocardiograms of five minutes duration for population screening has not been fully explored. Our study aims to investigate the utility of Deceleration Capacity derived from short-term electrocardiograms as a scalable, fully-automated screening tool for predicting long-term mortality risk in the general population. Within a cohort of a representative population-based survey in Germany (KORA-KMC-study), 823 participants with sinus rhythm aged 27 to 76 years at enrollment (females 47.4%) were followed for a median of 13.4 years (IQR 13.1–13.6). All-cause mortality was defined as the primary endpoint and observed in 159 participants. Deceleration Capacity was calculated from 5-minute 12-lead electrocardiograms by a fully automated approach. Participants were divided into three predefined risk categories: DCcategory0 – low-risk (> 4.5ms); DCcategory1 – intermediate-risk (2.5-4.5ms); and DCcategory2 – high-risk (≤ 2.5ms). More than two-thirds of the participants (n = 564, 68.5%) fell into DCcategory0, about one-fifth (n = 168, 20.4%) into DCcategory1, and about one-tenth (n = 91, 11.1%) into DCcategory2. Estimated 13-years mortality in the risk groups was 16.7%, 23.5%, and 49.1%, respectively (p < 0.001). Adjusting for age, life-style-related risk factors, and comorbidities, increased mortality risk was observed for DCcategory2 (HR 2.34, 95%-CI 1.56–3.50). Deceleration Capacity, derived automatically from brief 5-minute electrocardiogram recordings, emerges as a robust, feasible, and independent predictor of long-term mortality risk in the general population.

Increases in beat-to-beat variability of electrocardiographic QT interval duration have repeatedly been associated with increased risk of cardiovascular events and complications. The measurements of QT variability are frequently normalized for the underlying RR interval variability. Such normalization supports the concept of the so-called immediate RR effect which relates each QT interval to the preceding RR interval. The validity of this concept was investigated in the present study together with the analysis of the influence of electrocardiographic morphological stability on QT variability measurements. The analyses involved QT and RR measurements in 6,114,562 individual beats of 642,708 separate 10-s ECG samples recorded in 523 healthy volunteers (259 females). Only beats with high morphology correlation (r > 0.99) with representative waveforms of the 10-s ECG samples were analyzed, assuring that only good quality recordings were included. In addition to these high correlations, SDs of the ECG signal difference between representative waveforms and individual beats expressed morphological instability and ECG noise. In the intra-subject analyses of both individual beats and of 10-s averages, QT interval variability was substantially more strongly related to the ECG noise than to the underlying RR variability. In approximately one-third of the analyzed ECG beats, the prolongation or shortening of the preceding RR interval was followed by the opposite change of the QT interval. In linear regression analyses, underlying RR variability within each 10-s ECG sample explained only 5.7 and 11.1% of QT interval variability in females and males, respectively. On the contrary, the underlying ECG noise contents of the 10-s samples explained 56.5 and 60.1% of the QT interval variability in females and males, respectively. The study concludes that the concept of stable and uniform immediate RR interval effect on the duration of subsequent QT interval duration is highly questionable. Even if only stable beat-to-beat measurements of QT interval are used, the QT interval variability is still substantially influenced by morphological variability and noise pollution of the source ECG recordings. Even when good quality recordings are used, noise contents of the electrocardiograms should be objectively examined in future studies of QT interval variability.

Three-dimensional angle between the QRS complex and T wave vectors is a known powerful cardiovascular risk predictor. Nevertheless, several physiological properties of the angle are unknown or poorly understood. These include, among others, intra-subject profiles and stability of the angle relationship to heart rate, characteristics of angle/heart-rate hysteresis, and the changes of these characteristics with different modes of QRS-T angle calculation. These characteristics were investigated in long-term 12-lead Holter recordings of 523 healthy volunteers (259 females). Three different algorithmic methods for the angle computation were based on maximal vector magnitude of QRS and T wave loops, areas under the QRS complex and T wave curvatures in orthogonal leads, and weighted integration of all QRS and T wave vectors moving around the respective 3-dimensional loops. These methods were applied to orthogonal leads derived either by a uniform conversion matrix or by singular value decomposition (SVD) of the original 12-lead ECG, giving 6 possible ways of expressing the angle. Heart rate hysteresis was assessed using the exponential decay models. All these methods were used to measure the angle in 659,313 representative waveforms of individual 10-s ECG samples and in 7,350,733 individual beats contained in the same 10-s samples. With all measurement methods, the measured angles fitted second-degree polynomial regressions to the underlying heart rate. Independent of the measurement method, the angles were found significantly narrower in females (p < 0.00001) with the differences to males between 10o and 20o, suggesting that in future risk-assessment studies, different angle dichotomies are needed for both sexes. The integrative method combined with SVD leads showed the highest intra-subject reproducibility (p < 0.00001). No reproducible delay between heart rate changes and QRS-T angle changes was found. This was interpreted as a suggestion that the measurement of QRS-T angle might offer direct assessment of cardiac autonomic responsiveness at the ventricular level.

Survivors of an acute myocardial infarction with diabetes mellitus retain an increased mortality risk. Reliable assessment of individual risk is required for effective and cost-efficient medical care in these patients. The Polyscore is a previously established risk predictor consisting of seven autonomic tests derived from electrocardiogram, blood pressure, and respiration. The Polyscore allows classification of survivors of myocardial infarction in groups at low, intermediate and high mortality risk. The aim of this study was to investigate the prognostic value of the Polyscore in diabetic survivors of acute myocardial infarction, which may be impaired by the presence of diabetic autonomic neuropathy. Survivors of an acute myocardial infarction were included in a prospective cohort study during hospitalisation due to the index event at two university hospitals in Munich, Germany. The Polyscore was determined from simultaneous non-invasive 30-min recordings of electrocardiogram, continuous arterial blood pressure, and respiration which were performed in all participants. Patients were followed for 5 years. The primary and secondary outcomes were all-cause mortality and cardiac mortality. 184 of 941 enrolled patients (19.6%) suffered from diabetes mellitus. 5-year-mortality was higher in diabetic patients (15.2%) compared to non-diabetic patients (5.8%). A multivariable Cox regression model confirmed the Polyscore as a strong predictor of mortality in diabetic post-MI patients (intermediate risk: HR 6.56, 95% CI 1.61–26.78, p = 0.004, mortality 22.8%; high risk: HR 18.76, 95% CI 4.35–80.98, p < 0.001, mortality 68.8%). There was no interaction between diabetes mellitus and the Polyscore regarding mortality prediction (p = 0.775). Interestingly, in contrast to the groups at intermediate and high risk (73 patients, 39.7%), the Polyscore identified a majority of diabetic patients (111, 60.3%) with a low mortality risk, comparable to that of low-risk non-diabetic patients (3.6% and 2.1%, respectively, p = 0.339). Consistent results were observed for cardiac mortality. This analysis shows that the Polyscore predicts all-cause and cardiac mortality in diabetic survivors of acute myocardial infarction. Within these patients it identifies a large population not affected by the excess mortality associated with diabetes in this setting. Thus, the Polyscore may facilitate risk-adapted follow-up strategies in diabetic survivors of myocardial infarction.

While it is now well-understood that the extent of QT interval changes due to underlying heart rate differences (i.e., the QT/RR adaptation) needs to be distinguished from the speed with which the QT interval reacts to heart rate changes (i.e., the so-called QT/RR hysteresis), gaps still exist in the physiologic understanding of QT/RR hysteresis processes. This study was designed to address the questions of whether the speed of QT adaptation to heart rate changes is driven by time or by number of cardiac cycles; whether QT interval adaptation speed is the same when heart rate accelerates and decelerates; and whether the characteristics of QT/RR hysteresis are related to age and sex. The study evaluated 897,570 measurements of QT intervals together with their 5-min histories of preceding RR intervals, all recorded in 751 healthy volunteers (336 females) aged 34.3 ± 9.5 years. Three different QT/RR adaptation models were combined with exponential decay models that distinguished time-based and interval-based QT/RR hysteresis. In each subject and for each modelling combination, a best-fit combination of modelling parameters was obtained by seeking minimal regression residuals. The results showed that the response of QT/RR hysteresis appears to be driven by absolute time rather than by the number of cardiac cycles. The speed of QT/RR hysteresis was found decreasing with increasing age whilst the duration of individually rate corrected QTc interval was found increasing with increasing age. Contrary to the longer QTc intervals, QT/RR hysteresis speed was faster in females. QT/RR hysteresis differences between heart rate acceleration and deceleration were not found to be physiologically systematic (i.e., they differed among different healthy subjects), but on average, QT/RR hysteresis speed was found slower after heart rate acceleration than after rate deceleration.

The normal physiologic range of QRS complex duration spans between 80 and 125 ms with known differences between females and males which cannot be explained by the anatomical variations of heart sizes. To investigate the reasons for the sex differences as well as for the wide range of normal values, a technology is proposed based on the singular value decomposition and on the separation of different orthogonal components of the QRS complex. This allows classification of the proportions of different components representing the 3-dimensional representation of the electrocardiographic signal as well as classification of components that go beyond the 3-dimensional representation and that correspond to the degree of intricate convolutions of the depolarisation sequence. The technology was applied to 382,019 individual 10-s ECG samples recorded in 639 healthy subjects (311 females and 328 males) aged 33.8 ± 9.4 years. The analyses showed that QRS duration was mainly influenced by the proportions of the first two orthogonal components of the QRS complex. The first component demonstrated statistically significantly larger proportion of the total QRS power (expressed by the absolute area of the complex in all independent ECG leads) in females than in males (64.2 ± 11.6% vs 59.7 ± 11.9%, p < 0.00001—measured at resting heart rate of 60 beats per minute) while the second component demonstrated larger proportion of the QRS power in males compared to females (33.1 ± 11.9% vs 29.6 ± 11.4%, p < 0.001). The analysis also showed that the components attributable to localised depolarisation sequence abnormalities were significantly larger in males compared to females (2.85 ± 1.08% vs 2.42 ± 0.87%, p < 0.00001). In addition to the demonstration of the technology, the study concludes that the detailed convolution of the depolarisation waveform is individual, and that smoother and less intricate depolarisation propagation is the mechanism likely responsible for shorter QRS duration in females.

Monitoring of QTc interval is mandated in different clinical conditions. Nevertheless, intra-subject variability of QTc intervals reduces the clinical utility of QTc monitoring strategies. Since this variability is partly related to QT heart rate correction, 10 different heart rate corrections (Bazett, Fridericia, Dmitrienko, Framingham, Schlamowitz, Hodges, Ashman, Rautaharju, Sarma, and Rabkin) were applied to 452,440 ECG measurements made in 539 healthy volunteers (259 females, mean age 33.3 ± 8.4 years). For each correction formula, the short term (5-min time-points) and long-term (day-time hours) variability of rate corrected QT values (QTc) was investigated together with the comparisons of the QTc values with individually corrected QTcI values obtained by subject-specific modelling of the QT/RR relationship and hysteresis. The results showed that (a) both in terms of short-term and long-term QTc variability, Bazett correction led to QTc values that were more variable than the results of other corrections ( p < 0.00001 for all), (b) the QTc variability by Fridericia and Framingham corrections were not systematically different from each other but were lower than the results of other corrections ( p -value between 0.033 and < 0.00001), and (c) on average, Bazett QTc values departed from QTcI intervals more than the QTc values of other corrections. The study concludes that (a) previous suggestions that Bazett correction should no longer be used in clinical practice are fully justified, (b) replacing Bazett correction with Fridericia and/or Framingham corrections would improve clinical QTc monitoring, (c) heart rate stability is needed for valid QTc assessment, and (d) development of further QTc corrections for day-to-day use is not warranted.

Abstract Aims Present society is constantly ageing and elderly frequently suffer from conditions that are difficult and/or costly to treat if detected late. Effective screening of the elderly is therefore needed so that those requiring detailed clinical work-up are identified early. We present a prospective validation of a screening strategy based on a Polyscore of seven predominantly autonomic, non-invasive risk markers. Methods and results Within a population-based survey in Germany (INVADE study), participants aged ≥60 years were enrolled between August 2013 and February 2015. Seven prospectively defined Polyscore components were obtained during 30-min continuous recordings of electrocardiogram, blood pressure, and respiration. Out of 1956 subjects, 168 were excluded due to atrial fibrillation, implanted pacemaker, or unsuitable recordings. All-cause mortality over a median 4-year follow-up was prospectively defined as the primary endpoint. The Polyscore divided the investigated population (n = 1788, median age: 72 years, females: 58%) into three predefined groups with low (n = 1405, 78.6%), intermediate (n = 326, 18.2%), and high risk (n = 57, 3.2%). During the follow-up, 82 (4.6%) participants died. Mortality in the Polyscore-defined risk groups was 3.4%, 7.4%, and 17.5%, respectively (P < 0.0001). The Polyscore-based mortality prediction was independent of Framingham score, diabetes, chronic kidney disease, and major stroke and/or myocardial infarction history. It was particularly effective in those aged <75 years (n = 1145). Conclusion The Polyscore-based mortality risk assessment from short-term non-invasive recordings is effective in the elderly general population, especially those aged 60–74 years. Implementation of a comprehensive Polyscore screening of this age group is proposed to advance preventive medical care.

AbstractIntroductionSudden cardiac death (SCD) is the leading cause of death in patients with myocardial infarction (MI) and can be prevented by the implantable cardioverter defibrillator (ICD). Currently, risk stratification for SCD and decision on ICD implantation are based solely on impaired left ventricular ejection fraction (LVEF). However, this strategy leads to over- and under-treatment of patients because LVEF alone is insufficient for accurate assessment of prognosis. Thus, there is a need for better risk stratification. This is the study protocol for developing and validating a prediction model for risk of SCD in patients with prior MI.Methods and AnalysisThe EU funded PROFID project will analyse 23 datasets from Europe, Israel and the US (∼225,000 observations). The datasets include patients with prior MI or ischemic cardiomyopathy with reduced LVEF<50%, with and without a primary prevention ICD. Our primary outcome is SCD in patients without an ICD, or appropriate ICD therapy in patients carrying an ICD as a SCD surrogate. For analysis, we will stack 18 of the datasets into a single database (datastack), with the remaining analysed remotely for data governance reasons (remote data). We will apply 5 analytical approaches to develop the risk prediction model in the datastack and the remote datasets, all under a competing risk framework: 1) Weibull model, 2) flexible parametric survival model, 3) random forest, 4) likelihood boosting machine, and 5) neural network. These dataset-specific models will be combined into a single model (one per analysis method) using model aggregation methods, which will be externally validated using systematic leave-one-dataset-out cross-validation. Predictive performance will be pooled using random effects meta-analysis to select the model with best performance.Ethics and disseminationLocal ethical approval was obtained. The final model will be disseminated through scientific publications and a web-calculator. Statistical code will be published through open-source repositories.

Background: Baseline right ventricular (RV) dysfunction represents a predictor for poor outcome in patients undergoing transcatheter aortic valve replacement (TAVR). flowever, RV function may improve after TAVR, which could have important implications on outcomes. The aim of the present study was to assess changes in RV function after TAVR and its prognostic value regarding clinical outcome. Methods and Results: Patients undergoing TAVR at our institution were consecutively enrolled and categorized into 4 groups according to changes in RV function during echocardiographic follow-up at 6 months. A total of 188 patients were included. Of those showing normal function at baseline. 87% (130/149) had preserved RV function at follow-up (group 1), whereas 13% (19/149) developed new RV dysfunction (group 2). Of those with RV dysfunction at baseline (39 patients), RV function normalized in 46% (18/39) (group 3) and remained impaired in 54% (21/39) (group 4). The Kaplan-Meier estimated survival at 3 years was highest in patients in group 1 (83%), intermediate in group 2 (65%) and 3 (69%), whereas group 4 had the worst survival (37%; P < .001). Furthermore, new or persistent RV dysfunction was identified to be independently associated with mortality during follow-up (hazard ratio 2.55: interquartile range 1.03-6.47, P = .004). Conclusions: Patients with preserved RV function have a high 3-year survival. Normalization of RV function showed improved survival compared with patients with persistent RV dysfunction, who had a dismal prognosis despite TAVR.

Long-term health consequences in survivors of severe COVID-19 remain unclear. Eighteen COVID-19 patients admitted to the intensive care unit at the University Hospital Rechts der Isar, Munich, Germany, between 14 March and 23 June 2020, were prospectively followed-up at a median of 36, 75.5, 122 and 222 days after discharge. The health-related quality of life (HrQoL) (36-item Short Form Health Survey and St. George’s Respiratory Questionnaire, SGRQ), cardiopulmonary function, laboratory parameters and chest imaging were assessed longitudinally. The HrQoL assessment revealed a reduced physical functioning, as well as increased SGRQ impact and symptoms scores that all improved over time but remained markedly impaired compared to the reference groups. The median radiological severity scores significantly declined; persistent abnormalities were found in 33.3% of the patients on follow-up. A reduced diffusion capacity was the most common abnormal pulmonary function parameter. The length of hospitalization correlated with role limitations due to physical problems, the SGRQ symptom and the impact score. In conclusion, in survivors of severe COVID-19, the pulmonary function and symptoms improve over time, but impairments in their physical function and diffusion capacity can persist over months. Longer follow-up studies with larger cohorts will be necessary to comprehensively characterize long-term sequelae upon severe COVID-19 and to identify patients at risk.