Embolic Stroke of Undetermined Source in Latin America: A Review

Environmental Fe, Ti, Al, Cu, Hg, Bi, and Si Nanoparticles in the Atrioventricular Conduction Axis and the Associated Ultrastructural Damage in Young Urbanites: Cardiac Arrhythmias Caused by Anthropogenic, Industrial, E-Waste, and Indoor Nanoparticles

Air pollution exposure is a risk factor for arrhythmia. The atrioventricular (AV) conduction axis is key for the passage of electrical signals to ventricles. We investigated whether environmental nanoparticles (NPs) reach the AV axis and whether they are associated with ultrastructural cell damage. Here, we demonstrate the detection of the shape, size, and composition of NPs by transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometry (EDX) in 10 subjects from Metropolitan Mexico City (MMC) with a mean age of 25.3 ± 5.9 and a 71-year-old subject without cardiac pathology. We found that in every case, Fe, Ti, Al, Hg, Cu, Bi, and/or Si spherical or acicular NPs with a mean size of 36 ± 17 nm were present in the AV axis in situ, freely and as conglomerates, within the mitochondria, sarcomeres, lysosomes, lipofuscin, and/or intercalated disks and gap junctions of Purkinje and transitional cells, telocytes, macrophages, endothelium, and adjacent atrial and ventricular fibers. Erythrocytes were found to transfer NPs to the endothelium. Purkinje fibers with increased lysosomal activity and totally disordered myofilaments and fragmented Z-disks exhibited NP conglomerates in association with gap junctions and intercalated disks. AV conduction axis pathology caused by environmental NPs is a plausible and modifiable risk factor for understanding common arrhythmias and reentrant tachycardia. Anthropogenic, industrial, e-waste, and indoor NPs reach pacemaker regions, thereby increasing potential mechanisms that disrupt the electrical impulse pathways of the heart. The cardiotoxic, oxidative, and abnormal electric performance effects of NPs in pacemaker locations warrant extensive research. Cardiac arrhythmias associated with nanoparticle effects could be preventable.

Care of the Patient with Acquired Brain Injury in Latin America and the Caribbean

Traumatic brain injury and stroke are the leading causes of death and disability in Latin American and Caribbean countries. Specific characteristics, models of health care systems, and risk factors may influence the patient's outcome in this region. Relevant literature suggest that important delay problems exist in seeking care, reaching care, and receiving care in patients with acute neurologic injuries. Minimizing the time lost before care can be provided are vital to reduce the morbidity, long-term disability, and improved survival.

Regional, sex, and age differences in diagnostic testing among participants in the NAVIGATE-ESUS trial

BACKGROUND AND AIM

The diagnosis of embolic stroke of undetermined source (ESUS) is based on excluding other more likely stroke etiologies, and therefore diagnostic testing plays an especially crucial role. Our objective was to compare the diagnostic testing by region, sex, and age among the participants of NAVIGATE-ESUS trial.

METHODS

Participants were grouped according to five global regions (North America, Latin America, Western Europe, Eastern Europe and East Asia), age (<60, 60-74, and >75 years), and sex. Frequencies of each diagnostic test within areas of echocardiography, cardiac rhythm monitoring, and arterial imaging were described and compared across groups. A multivariable logistic regression model for each diagnostic test was fit to assess the independent influence of each of region, age, and sex and likelihood of testing.

RESULTS

We included 6985 patients in the analysis (918 from North America; 746 from Latin America; 2853 from Western Europe; 1118 from Eastern Europe; 1350 from East Asia). Average age (highest in Western Europe (69 years), lowest in Eastern Europe (65 years)), % females (highest in Latin America (44%) and lowest in East Asia (31%)), and use of each diagnostic test varied significantly across regions. Region, but not sex, was independently associated with use of each diagnostic test examined. Transesophageal echocardiography and either CT or MR angiogram were more often used in younger patients.

CONCLUSION

Diagnostic testing differed by region, and less frequently by age, but not by sex. Our findings reflect the existing variations in global practice in diagnostic testing in ESUS patients.

Embolic Stroke of Undetermined Source in Saudi Arabia: Prevalence, Patient Characteristics, and Outcomes

BACKGROUND

Embolic stroke of undetermined source (ESUS) is a newly introduced clinical construct to better characterize cryptogenic stroke. It is associated with considerable morbidity and mortality and a high recurrence rate. It has not previously been investigated in Saudi stroke patients. We aimed to conduct a descriptive analysis of ESUS in Saudi Arabia, including its frequency among patients with acute stroke, characteristics, and outcomes.

METHODS

We reviewed all ischemic stroke patients admitted to the stroke unit at King Abdulaziz Medical City-Riyadh, Saudi Arabia, from February 2016 to July 2018. We applied the criteria proposed by the Cryptogenic Stroke/ESUS International Working Group, which defines ESUS as a radiologically confirmed nonlacunar brain infarct without (a) extracranial or intracranial atherosclerosis causing ≥50% stenosis in arteries supplying the ischemic area, (b) a major-risk cardioembolic source, (c) any other specific cause of stroke. We compared ESUS patients with the other stroke patients. Study was approved by local institutional review board.

RESULTS

Of the 736 patients admitted with ischemic stroke, 147 (20%) had ESUS. Patients with ESUS had fewer vascular risk factors compared to patients without ESUS. Nearly third were either dead or dependent at discharge. There were no significant differences between ESUS and other types of ischemic strokes in mortality rate and independence at discharge.

CONCLUSION

ESUS is common in Saudi stroke patients. Despite of the lack of definite etiology, it is associated with considerable morbidity and mortality.

[Ischemic stroke related to spontaneous]

Cardiovascular disease in women is a particularly complex pathology especially in the youngest population. The clinical presentation of acute coronary syndromes is sometimes misleading and does not necessarily point to the potential presence of cardiac disease given the frequent absence of cardiovascular risks. Such complexity results in delayed diagnosis, which worsens the outcome of myocardial infarction and generates complications related to the absence of coronary revascularization. We report the case of a patient who suffered an (undiagnosed) apical myocardial infarction that went undetected and was complicated by a voluminous intraventricular thrombus with embolus migration in the cerebral circulation resulting in an ischemic accident. The combination of these two pathologies make their therapeutic management particularly difficult. As widely reported in the literature, the outcome of myocardial infarction in women is poorer than in their male counterparts for a number of reasons. We can assume that in the youngest patients, another physiopathological mechanism is often involved, namely, the occurrence of hematoma and spontaneous coronary dissection. Diagnosis is often difficult even with coronary angiography diagnosis. As shown in the case reported here, initial examination results, if not thoroughly analyzed, may be erroneously interpreted as normal. It is also likely that the presence of hematoma or coronary wall dissection without any plaque rupture may negatively influence the outcome owing to the implementation of inappropriate treatments. In conclusion, in patients presenting with an ischemic cerebral accident, meticulous cardiac examination must be performed even in young women with no cardiovascular risk factors given that the occurrence of hematoma or coronary dissection may contribute to the formation of mural thrombi in the setting of myocardial infarction. Cardiac MRI seems to be particularly effective in the diagnosis of myocardial infarction complicated by the presence of intracavitary thrombi.