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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.

Background Cerebral hypoperfusion before syncope has been shown in patients with chronic orthostatic intolerance (OI) without tachycardia, but it is unknown if an initial decrease of cerebral blood flow velocity (CBFv) could be related to the vasovagal response (VVR) to head-up tilt test (HUTT). Objective The objective of the study was to compare cardiovascular, cerebrovascular, and autonomic variables during HUTT in OI patients with or without a VVR. Methods We included 74 subjects (58% female, mean age 33 ± 12 years) who underwent a 30-min HUTT and were divided into three groups: OI with VVR positive (VVR+), OI without VVR negative (VVR-), and asymptomatic healthy subjects with negative HUTT (control group). Cardiovascular, cerebrovascular, and autonomic variables were assessed beat-to-beat during HUTT with a Task Force monitor and a trans-cranial Doppler. Mean values were evaluated at baseline and throughout the first 10 min of tilting. Results Cardiovascular variables were similar in the three groups. Systolic, diastolic, and mean CBFv were similar in VVR+ and VVR-, but both groups had lower CBFv than the control group. Systolic and diastolic CBFv decreased from baseline since min 1 in VVR+ and VVR- and since min 5 in the control group. The mean CBFv had a significant decrease since min 1 compared to baseline in all groups. Spectral indices of heart rate and blood pressure variability showed a similar autonomic response to HUTT in all groups. Conclusion Patients with chronic OI without tachycardia have early postural cerebral hypoperfusion, regardless of the VVR during HUTT.

Background: Atrial Fibrillation (AF) is associated with an increased risk of stroke and systemic embolism. Several studies have suggested that female AF patients could have a greater risk for stroke. There is scarce information about clinical characteristics and use of antithrombotic therapies in Latin American patients with nonvalvular AF. Objective: To describe the gender differences in clinical characteristics, thromboembolic risk, and antithrombotic therapy of patients with nonvalvular AF recruited in Mexico, an upper middle-income country, into the prospective national CARMEN-AF Registry. Methods: A total of 1423 consecutive patients, with at least one thromboembolic risk factor were enrolled in CARMEN-AF Registry during a three-year period (2014–2017). They were categorized according to Gender. Results: Overall, 48.6% were women, mean age 70 ± 12 years. Diabetes, smoking, alcoholism, non-ischemic cardiomyopathy, coronary artery disease, and obstructive sleep apnea were higher in men. Most women were found with paroxysmal AF (40.6%), and most men with permanent AF (44.0%). No gender differences were found in the use of vitamin K antagonists (VKA) (30.5% in women vs. 28.0% in men). No gender differences were found in the use of direct oral anticoagulants (DOAC) (33.8% women vs 35.4% men). Conclusions: CARMEN-AF Registry demonstrates that in Mexico, regardless of gender, a large proportion of patients remain undertreated. No gender differences were found in the use of VKA or DOAC. Keywords: Atrial fibrillation, Gender, Thromboembolic risk, Antithrombotic therapy, Stroke, Mexico

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 Although the underlying mechanisms of reflex syncope remain under debate, there is evidence that it results from decreased cardiac output related to splanchnic blood pooling or a fall in systemic vascular resistance. The aim was to evaluate the response of cerebrovascular and autonomic variables to passive orthostatic challenge in adult patients with different mechanisms leading to reflex syncope. Methods The study included 30 subjects (66% women, mean age 34 ± 14 years) who suffered a hemodynamic collapse during a drug-free head-up tilt test. They were categorized into three groups according to their hemodynamic cardiovascular response during the head-up tilt test: (1) reduced cardiac output (patients, n = 10), (2) reduced systemic vascular resistance (patients, n = 10), and (3) reduced cardiac output and systemic vascular resistance, (reduced cardiac output reduced systemic vascular resistance patients, n = 10). Cardiovascular and cerebrovascular dynamics, as well as autonomic variables, were noninvasively assessed during the head-up tilt test and median values were calculated at baseline and throughout the three phases of the tilt. Results At baseline, the reduced systemic vascular resistance group had lower cardiac output and higher total peripheral resistance index and a sustained increase of heart rate throughout the head-up tilt test in comparison to the other groups. Cerebrovascular dynamics and autonomic variables showed no difference among groups throughout the test. Compared with baseline, these variables had similar percentual change during the orthostatic challenge. Conclusions Although different cardiovascular hemodynamic mechanisms of reflex syncope exist in adult patients, cerebrovascular hypoperfusion and autonomic modulation occur to a similar extent.

Background: Documenting the patterns of oral anticoagulation therapy (OAT) is essential to prevent thromboembolic complications of nonvalvular atrial fibrillation (NVAF). Objective: 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. Material and methods: 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. Results: 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

Background The World Heart Federation has undertaken an initiative to develop a series of Roadmaps to promote development of national policies and health systems approaches, and to identify potential roadblocks on the road to effective prevention, detection, and management of cardiovascular disease in low-and middle-income countries (LMICs) and develop strategies for overcoming these. This Roadmap focuses on atrial fibrillation (AF). AF is the most common, clinically significant arrhythmia and, among other clinical outcomes, is associated with increased risk of stroke. Methods Development of this Roadmap included a review of published guidelines and research papers, and consultation with an expert committee comprising experts in clinical management of AF and health systems research in LMICs. The Roadmap identifies 1) key interventions for detection, diagnosis, and management of AF; 2) gaps in implementation of these interventions (knowledge-practice gaps); 3) health system roadblocks to implementation of AF interventions in LMICs; and 4) potential strategies for overcoming these. Results More research is needed on determinants and primary prevention of AF. Knowledge-practice gaps for detection, diagnosis, and management of AF are present worldwide, but may be more prominent in LMICs. Potential barriers to implementation of AF interventions include long distances to health facilities, shortage of health care professionals with training in AF, including interpretation of ECG, unaffordability of oral anticoagulants for patient households, reluctance on the part of physicians to initiate oral anticoagulant (OAC) therapy, and lack of awareness of the importance of persistent adherence to OAC therapy. Potential solutions include training of nonphysician health workers and pharmacists in pulse-taking, use of telemedicine technologies to transmit electrocardiogram results, engagement of nonphysician health workers in OAC therapy adherence support, and country-specific support and education programs for noncardiologist health care professionals. Conclusions AF affects millions of people worldwide and, left untreated, increases the risk and severity of stroke and heart failure. Although guidelines for the detection, diagnosis, and management of AF exist, there are gaps in implementation of these guidelines globally, and in particular in LMICs. This Roadmap identifies some potential solutions that may improve AF outcomes in LMICs but require further evaluation in these settings.

The purpose was to evaluate the effect of the disease duration prior to treatment, thyroid hormones level, or both on the reversibility of dilated cardiomyopathy. Between January 2006 and December 2010, a longitudinal study with a 6 months follow-up was carried on. One hundred and seventy patients with hyperthyroidism were referred to the cardiologist, and 127 had a 6 months followup after antithyroid treatment and were evaluated by echocardiography. Dilated cardiomyopathy reversibility criteria were established according to echocardiographic parameters. Complete reversibility existed when all parameters were met, partial reversibility when LVEF was ≥55% plus two or three other parameters, and no reversibility when LVEF was ≤55% regardless of other parameters. The results showed that echocardiography parameters related to the regression of myocardial mass were associated with a disease duration shorter than 10.38 months. This was the main predictive variable for reversal of dilated cardiomyopathy, followed byβ-blocker treatment, and the last predictive variable was the serum level of free triiodothyronine. This study showed that the effect on the myocardium related to thyrotoxicosis was associated with the disease duration before treatment.

Syncope is characterized by a sudden and brief Loss of the normal state of consciousness (fainting), caused by multiple factors (biological, psychological and social), which consequences can be Lethal if it is not timely diagnosed and treated. These episodes affect the total sphere of the subject (on an individual, work, school, social, and family level).Contribute to the study of vasovagal syncope (WS) patients, describing their personality and psychopathological characteristics.Minnesota Multiphasic Personality Inventory (MMPI) was used to evaluate psychopathology in a sample of 30 subjects diagnosed with (WS), attended in the National Institute of Cardiology "lgnacio Chávez", making a descriptive analysis of the complete sample, regarding demographic variables and inventory scores.The scales with higher scores found within these subjects were hypochondriasis (= 67.43), depression (= 69.83), hysteria (= 67.83) among others.In general, patients with (WS) show significant levels of anxiety and depression, dissatisfaction, bad mood, pessimism, concern, somatic complaints, difficulty to solve problems adaptively, among others. This study remarks the importance of knowing these characteristics to implement treatments that manage this disease properly and may improve patients quality of life, as well as their physical and mental health.

Vasovagal syncope is a common clinical problem forming the pathophysiological basis of half the cases of syncope. Although it usually has a favourable prognosis, it may be a highly limiting clinical problem in a particular subset of patients among whom syncopal recurrences are frequent and without prodromic symptoms, or have a traumatic outcome. For this subgroup of patients the term "malignant vasovagal syncope" has been proposed. The treatment of these highly symptomatic patients is necessary to avoid dangerous injuries and to improve the quality of life. Pacemaker therapy has been advocated as a potential therapy in severe or drug refractory cases. This paper reviews the concepts behind pacemaker therapy for vasovagal syncope and the results of various clinical trials that have evaluated its potential utility as a primary therapeutic modality.

Sudden cardiac death continues to be a significant health care problem. Patients with prior myocardial infarction, severe left ventricular dysfunction, and nonsustained ventricular tachycardia are at high risk for sudden death. Identification of patients prone to sudden cardiac death is still unresolved, although a number of strategies have been applied over the past two decades based on the degree of left ventricular dysfunction, frequency of spontaneous ventricular arrhythmias, and ventricular late potentials. It has been recognized that patients with myocardial infarction and depressed left ventricular function have enhanced sympathetic relative to vagal tone controlling cardiac rhythm and rate. This can be measured as depressed heart rate variability and baroreflex sensitivity. Other markers of risk have been explored, QT dispersion, post-extrasystolic heart rate turbulence and T wave alternans. Development of the automatic ICD has been one of the most spectacular achievements of the last 20 years in cardiology. The ICD reduces sudden death in postmyocardial infarction patients. Nevertheless, a clearer delineation is needed of the subsets of patients in whom an optimal medical regimen might be the best option for preventing sudden death.

Several studies have shown the role of focal trigers in the pulmonary veins initiating episodes of atrial fibrillation. Radiofrequency catheter ablation of this foci is a curative therapy for paroxysmal atrial fibrillation. We report a case of idiopathic paroxysmal atrial fibrillation triggered by abnormal electrical activity in a single pulmonary vein. Mapping was performed during sinus rhythm with a 4F decapolar catheter (Spiral Supreme, Daig, St. Jude Medical) positioned near the ostium by a transseptal approach. Pulmonary vein potentials were only identified in the left superior pulmonary vein. Segmental ostial ablation (30 W) performed during left atrial pacing resulted in complete cesation of conduction in the pulmonary vein. There were no complications. The clinical response (suppression of the paroxysms of atrial fibrillation in a 9-month follow-up) observed in this patient imply that atrial fibrillation was triggered by this pulmonary vein. This case report illustrates several aspects of catheter-based ablation of pulmonary vein foci for the treatment of paroxysmal atrial fibrillation and demonstrates its efficacy.