Telehealth: delivering high-quality care for heart failure

No abstract available

Prevention or procrastination for heart failure?: Why we need a universal definition of heart failure

No abstract available

Deterministic walks in random networks: an application to thesaurus graphs

In a landscape composed of N randomly distributed sites in Euclidean space, a walker (``tourist'') goes to the nearest one that has not been visited in the last \tau steps. This procedure leads to trajectories composed of a transient part and a final cyclic attractor of period p. The tourist walk presents universal aspects with respect to \tau and can be done in a wide range of networks that can be viewed as ordinal neighborhood graphs. As an example, we show that graphs defined by thesaurus dictionaries share some of the statistical properties of low dimensional (d=2) Euclidean graphs and are easily distinguished from random graphs. This approach furnishes complementary information to the usual clustering coefficient and mean minimum separation length.Comment: 12 pages, 5 figures, revised version submited to Physica A, corrected references to figure

Caring for people with heart failure and many other medical problems through and beyond the COVID‐19 pandemic; the advantages of universal‐access to home telemonitoring

No abstract available

The algebra of adjacency patterns: Rees matrix semigroups with reversion

We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion. In particular, the lattice of subvarieties of the variety generated by adjacency semigroups that are regular unary semigroups is essentially the same as the lattice of universal Horn classes of reflexive directed graphs. A number of examples follow, including a limit variety of regular unary semigroups and finite unary semigroups with NP-hard variety membership problems.Comment: 30 pages, 9 figure

Comparative effectiveness of enalapril, lisinopril, and ramipril in the treatment of patients with chronic heart failure: a propensity score-matched cohort study

Background: Angiotensin converting enzyme inhibitors (ACEIs) are recommended as first-line therapy in patients with heart failure with reduced ejection fraction (HFrEF). The comparative effectiveness of different ACEIs is not known. Methods and results: 4,723 out-patients with stable HFrEF prescribed either enalapril, lisinopril, or ramipril were identified from three registries in Norway, England, and Germany. In three separate matching procedures, patients were individually matched with respect to both dose equivalents and their respective propensity scores for ACEI treatment. During a follow-up of 21,939 patient-years, 360 (49.5%), 337 (52.4%), and 1,119 (33.4%) patients died amongst those prescribed enalapril, lisinopril, and ramipril, respectively. In univariable analysis of the general sample, enalapril and lisinopril were both associated with higher mortality as compared with ramipril treatment (HR 1.46, 95% CI 1.30-1.65, p < 0.001, and HR 1.38, CI 1.22-1.56, p < 0.001, respectively). Patients prescribed enalapril or lisinopril had similar mortality (HR 1.06, 95% CI 0.92-1.24, p = 0.41). However, there was no significant association between ACEI choice and all-cause mortality in any of the matched samples (HR 1.07, 95% CI 0.91-1.25, p = 0.40; HR 1.12, 95% CI 0.96-1.32, p = 0.16; and HR 1.08, HR 1.10, 95% CI 0.93-1.31, p = 0.25 for enalapril vs. ramipril, lisinopril vs. ramipril, and enalapril vs. lisinopril, respectively). Results were confirmed in subgroup analyses with respect to age, sex, left ventricular ejection fraction, NYHA functional class, cause of HFrEF, rhythm, and systolic blood pressure. Conclusion: Our results suggest that enalapril, lisinopril and ramipril are equally effective in the treatment of patients with HFrEF when given at equivalent doses

Electrocardiographic characteristics in patients with heart failure and normal ejection fraction: a systematic review and meta‐analysis

Background: Little is known about ECG abnormalities in patients with heart failure and normal ejection fraction (HeFNEF) and how they relate to different etiologies or outcomes. Methods and Results: We searched the literature for peer‐reviewed studies describing ECG abnormalities in HeFNEF other than heart rhythm alone. Thirty five studies were identified and 32,006 participants. ECG abnormalities reported in patients with HeFNEF include atrial fibrillation (prevalence 12%–46%), long PR interval (11%–20%), left ventricular hypertrophy (LVH, 10%–30%), pathological Q waves (11%–18%), RBBB (6%–16%), LBBB (0%–8%), and long JTc (3%–4%). Atrial fibrillation is more common in patients with HeFNEF compared to those with heart failure and reduced ejection fraction (HeFREF). In contrast, long PR interval, LVH, Q waves, LBBB, and long JTc are more common in patients with HeFREF. A pooled effect estimate analysis showed that QRS duration ≥120 ms, although uncommon (13%–19%), is associated with worse outcomes in patients with HeFNEF. Conclusions: There is high variability in the prevalence of ECG abnormalities in patients with HeFNEF. Atrial fibrillation is more common in patients with HeFNEF compared to those with HeFREF. QRS duration ≥120 ms is associated with worse outcomes in patients with HeFNEF. Further studies are needed to address whether ECG abnormalities correlate with different phenotypes in HeFNEF

Isoscalar Giant Dipole Resonance and Nuclear Matter Incompressibility Coefficient

We present results of microscopic calculations of the strength function, S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar giant dipole resonance (ISGDR). An accurate and a general method to eliminate the contributions of spurious state mixing is presented and used in the calculations. Our results provide a resolution to the long standing problem that the nuclear matter incompressibility coefficient, K, deduced from sigma(E) data for the ISGDR is significantly smaller than that deduced from data for the isoscalar giant monopole resonance (ISGMR).Comment: 4 pages using revtex 3.0, 3 postscript figures created by Mathematica 4.

Chronic obstructive pulmonary disease and heart failure: a breathless conspiracy

No abstract available

Development of a human model for the study of effects of hypoxia, exercise, and sildenafil on cardiac and vascular function in chronic heart failure

Background: Pulmonary hypertension is associated with poor outcome in patients with chronic heart failure (CHF) and may be a therapeutic target. Our aims were to develop a noninvasive model for studying pulmonary vasoreactivity in CHF and characterize sildenafil's acute cardiovascular effects. Methods and Results: In a crossover study, 18 patients with CHF participated 4 times [sildenafil (2 × 20 mg)/or placebo (double-blind) while breathing air or 15% oxygen] at rest and during exercise. Oxygen saturation (SaO2) and systemic vascular resistance were recorded. Left and right ventricular (RV) function and transtricuspid systolic pressure gradient (RVTG) were measured echocardiographically. At rest, hypoxia caused SaO2 (P = 0.001) to fall and RVTG to rise (5 ± 4 mm Hg; P = 0.001). Sildenafil reduced SaO2 (−1 ± 2%; P = 0.043), systemic vascular resistance (−87 ± 156 dyn·s−1·cm−2; P = 0.034), and RVTG (−2 ± 5 mm Hg; P = 0.05). Exercise caused cardiac output (2.1 ± 1.8 L/min; P < 0.001) and RVTG (19 ± 11 mm Hg; P < 0.0001) to rise. The reduction in RVTG with sildenafil was not attenuated by hypoxia. The rise in RVTG with exercise was not substantially reduced by sildenafil. Conclusions: Sildenafil reduces SaO2 at rest while breathing air, this was not exacerbated by hypoxia, suggesting increased ventilation–perfusion mismatching due to pulmonary vasodilation in poorly ventilated lung regions. Sildenafil reduces RVTG at rest and prevents increases caused by hypoxia but not by exercise. This study shows the usefulness of this model to evaluate new therapeutics in pulmonary hypertension