Antonio Gonzalez-Hermosillo

The aim of this study was to assess the heart rate variability (HRV) at rest and during active orthostatic challenge in long COVID patients with orthostatic intolerance symptoms (dizziness, pre-syncope, and syncope). We performed a cross-sectional, observational, comparative study of 60 subjects of both sexes, aged 18 to 60 years (31 met the criteria of long COVID, 15 were infected individuals without symptoms, and 14 who had neither infection nor symptoms formed the age-matched control group). HRV was obtained from continuous electrocardiograms in a supine position and active standing with spontaneous breathing. The time from SARS-CoV-2 infection to testing in the COVID-19 group was 573 ± 289 days. The resting (supine position) values of SDNN, RMSSD, SD1, and SD2 were lower in long COVID patients than in control participants, while all other HRV indexes were similar between groups. In response to active standing, both groups had similar changes in all HRV indices. In conclusion, an active orthostatic test was not able to exhibit an autonomic dysregulation in these patients with long COVID, suggesting that cardiac autonomic modulation may have recovered due to the long time that elapsed after SARS-CoV-2 infection.

Objective: Identify, trough a vasovagal signs and symptoms questionnaire, blood donors in order to record the antecedents that increases the probability of presenting vasovagal reactions. Materials and Methods: A questionnaire was applied to blood donors, for three months, in the blood bank in a third-level health institution. Results: 100% of the donors answered negatively to the questions in the questionnaire, but 1.3% of them presented vasovagal reaction, with dizziness, pallor and nausea being the most frequently shown sing and symptoms. When comparing two groups with and without vasovagal reaction matched by sex, age and body mass index, there were no differences between them. Conclusions: Donors in our country are fundamentally replacement donors, so this circumstance plus their motivations should be considered for the design of surveys aimed at this population. Keywords: Vasovagal; Blood donors; Replacement

Background Autonomic dysfunction is commonly observed in patients with long-standing type 2 diabetes. Previous studies have confirmed the value of both subjectively assessed symptoms and objective measurements of autonomic nervous system function in diagnosing cardiovascular autonomic neuropathy. However, the head-up tilt test (HUTT) has been rarely used to investigate cardiovascular autonomic responses in subjects with high risk of newly diagnosed type 2 diabetes (nT2D). Objective To evaluate autonomic cardiovascular responses through passive orthostatic challenge along the diabetes continuum. Methods The study population was stratified as normoglycemic (n = 16), prediabetes (n = 20), and nT2D (n = 20). The prevalence of orthostatic intolerance and autonomic cardiovascular responses was evaluated with the Task Force Monitor during a 30-min passive HUTT. Spectral indices of heart rate and blood pressure variability and baroreceptor effectiveness index (BEI) were calculated through the HUTT. BEI was obtained by the sequence method. Results There were no differences in the prevalence of orthostatic intolerance or in the indices of heart rate and blood pressure variability among the three groups of study. The BEI was attenuated in the nT2D group in supine rest and throughout HUTT compared with normoglycemic and prediabetes groups. The multivariable linear regression analysis showed that BEI was associated with fasting glucose (β = − 0.52, p < 0.001) and HbA1c (β = − 0.57, p < 0.001) independently of cardiovascular risk factors. Conclusion Cardiovascular autonomic neuropathy, expressed as blunted BEI, is the only abnormal autonomic nervous test detected in nT2D, and it was independently associated with fasting glucose and HbA1c values.

The aim of this study was to describe the clinical evolution during 6 months of follow-up of adults recovered from COVID-19. We tried to determine how many met the definition of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). A total of 130 patients (51.0 ± 14 years, 34.6% female) were enrolled. Symptoms were common, participants reported a median number of 9 (IQR 5–14) symptoms. Fatigue was the most common symptom (61/130; 46.9%). Patients with fatigue were older 53.9 ± 13.5 years compared with 48.5 ± 13.3 years in those without fatigue (p = 0.02) and had a longer length of hospital stay, 17 ± 14 days vs. 13 ± 10 days (p = 0.04). There was no difference in other comorbidities between patients with fatigue and those without it, and no association between COVID-19 severity and fatigue. After multivariate adjustment of all baseline clinical features, only age 40 to 50 years old was positively associated with fatigue, OR 2.5 (95% CI 1.05–6.05) p = 0.03. In our survey, only 17 (13%) patients met the Institute of Medicine’s criteria for “systemic exertion intolerance disease,” the new name of ME/CFS. In conclusion, in some patients, the features of post-acute COVID-19 syndrome overlap with the clinical features of ME/CFS.

Purpose: The mechanisms underlying orthostatic hypertension (OHT) remain poorly understood. The authors evaluated the cardiovascular, cerebrovascular dynamics, and autonomic response to head-up tilt test (HUTT) in young adults with symptoms of orthostatic intolerance and transient OHT. Methods: Forty-four female subjects were included (34 ± 13 years old) and categorized in three groups after a 30-minute 70° passive HUTT: symptomatic patients with OHT (surge of systolic blood pressure ≥20 mm Hg for at least 5 minutes at any given time during HUTT), orthostatic intolerance (symptomatic patients without orthostatic blood pressure changes), and healthy asymptomatic control subjects. Results: At baseline, OHT patients had lower systolic blood pressure than orthostatic intolerance patients (103 ± 8 vs. 116 ± 10 mm Hg, p < 0.01) and lower baroreflex sensitivity than control subjects (15.8 ± 8.3 vs. 27.1 ± 11.7 ms/mm Hg, p = 0.01). On tilt, cardiac output decreased in OHT patients from 6.1 ± 1.4 L/minute during baseline to 5.2 ± 0.8 L/minute after 10 minutes of HUTT (p = 0.01). In OHT patients at 30 minutes of HUTT, sympathetic efferent heart activity was higher (77.4 ± 14.9 normalized units or nu) than orthostatic intolerant patients (63.5 ± 11.8 nu, p = 0.02) and control subjects (65.8 ± 11.2 nu, p = 0.05). Cerebrovascular resistance in OHT was higher than control subjects after 30 minutes (2.2 ± 0.8 vs. 1.6 ± 0.3 cm/second, respectively, p = 0.02). Conclusions: This study demonstrates that transient OHT can occur at any given time during HUTT. These patients exhibit a decrease in cardiac output and a hyperadrenergic response to tilt.

Documenting the patterns of oral anticoagulation therapy (OAT) is essential to prevent thromboembolic complications of nonvalvular atrial fibrillation (NVAF). To report the patterns of OAT according to age and thromboembolic risk in patients included in CARMEN-AF, a nationwide registry of NVAF in Mexico, an upper middle-income country. There were 1,423 consecutive patients ≥18 years old and with at least one thromboembolic risk factor enrolled in the CARMEN-AF Registry at their regular clinical visit during a three-year period. They were analyzed according to 1) age, 2) AF type, and 3) CHA2DS2-VASc score. Overall, 16.4% of patients did not receive antithrombotic treatment, 19.4% received antiplatelet drugs (APD), 29.2% vitamin K antagonists (VKA), and 34.6% direct oral anticoagulants (DOAC). With increasing age, the proportion of subjects treated with VKA decreased significantly from 36.2% in subjects <65 years to 22.5% in those ≥75 years old (P <0.0001). Concomitantly, an increase in both APD and no antithrombotic treatment was observed with increasing age. DOAC were prescribed equally among all age groups (34.2% in <65, 36.0% in 65–74, and 33.9% in ≥75). According to the type of AF, VKA use was more common in patients with permanent AF (32.7%). A lower use of DOAC was observed in high thromboembolic risk subjects (33.6% in CHA2DS2-VASc ≥2) compared with the moderate risk group (41% in CHA2DS2-VASc = 1). VKA use for NVAF in Mexico decreased in relation to increasing age. The proportion of DOAC therapy was the same in all age groups. Nevertheless, elderly patients with high thromboembolic risk received a suboptimal thromboprophylaxis. These data could help to improve gaps in the implementation of global guidelines. http://www.clinicaltrials.gov. Unique identifier: NCT02334852.

The effect of an orthostatic stress on cardiovascular and respiratory complexity was investigated to detect impaired autonomic regulation in patients with vasovagal syncope (VVS). Sixteen female patients and 12 age-matched healthy female subjects were enrolled in a passive 70° head-up tilt test. Also, 12 age-matched healthy male subjects were enrolled to study gender differences. Analysis was performed dynamically using various short-term (5 min) windows shifted by 1 min as well as by 20 min of orthostatic phase (OP) to evaluate local and global complexity. Complexity was determined over multiple time scales by the established method of refined composite multiscale entropy (RCMSE) and by a new proposed method of multiscale entropy based on symbolic dynamics (MSE-SD). Concerning heart rate variability (HRV) during OP, both methods revealed the highest complexity for female controls followed by lower complexity in male controls (p<0.01) and by the lowest complexity in female patients (p<0.01). For blood pressure variability (BPV), no gender differences in controls were shown by any method. However, MSE-SD demonstrated highly significantly increased BPV complexity in patients during OP (p<0.01 on 4 time-scales after 7 min, p<0.001 on 5 time-scales after 11 min), while RCMSE did not reveal considerable differences (p<0.05 on 2 time scales after 7 min). Respiratory complexity was further increased in patients primary shown by MSE-SD. Findings indicated impaired autonomic regulation in VVS patients characterized by predominantly increased BPV complexity accompanied with decreased HRV complexity. In addition, results suggested extending the concept of complexity loss with disease.

Vitamin K antagonists are highly effective in preventing stroke in patients with atrial fibrillation but have several limitations. Apixaban is a novel oral direct factor Xa inhibitor that has been shown to reduce the risk of stroke in a similar population in comparison with aspirin.