Implantable Cardioverter-Defibrillator Placement in Spontaneous Coronary Artery Dissection: A Case Report.

BACKGROUND Spontaneous coronary artery dissection can present with acute coronary syndrome, ventricular arrhythmias, or sudden cardiac death. Implantable cardioverter-defibrillator placement in patients with spontaneous coronary artery dissection is controversial. The purpose of publishing this case is to inform physicians of potential benefits of implantable cardioverter-defibrillator implantation in patients with spontaneous coronary artery dissection. CASE REPORT A 55-year-old woman presented with chest pain, with an electrocardiogram revealing anterior ST-elevation myocardial infarction and troponin peak of 53.8 ng/mL. Coronary angiography revealed mid-left anterior descending artery occlusion, with appearance of spontaneous coronary artery dissection that was not amenable to revascularization. The decision was made to treat medically. In recovery, the patient experienced ventricular fibrillation arrest. The patient was defibrillated once with achievement of return of spontaneous circulation. An Impella CP was placed to stabilize the patient. After the patient was stabilized, an implantable cardioverter-defibrillator was placed. CONCLUSIONS Data on potential benefits of implantable cardioverter-defibrillator placement in patients with spontaneous coronary artery dissection are limited. Most patients with spontaneous coronary artery dissection recover normal coronary architecture; however, there are no guidelines for implantable cardioverter-defibrillator placement in patients with spontaneous coronary artery dissection. Patients with spontaneous coronary artery dissection with high-risk features may benefit from implantable cardioverter-defibrillator for secondary prevention of ventricular arrhythmia and sudden cardiac death, as shown with this case.

Opioids Cause Sex-Specific Vascular Changes via Cofilin-Extracellular Signal-Regulated Kinase Signaling: Female Mice Present Higher Risk of Developing Morphine-Induced Vascular Dysfunction than Male Mice.

Recent studies have shown that chronic use of prescription or illicit opioids leads to an increased risk of cardiovascular events and pulmonary arterial hypertension. Indices of vascular age and arterial stiffness are also shown to be increased in opioid-dependent patients, with the effects being more marked in women. There are currently no studies investigating sex-specific vascular dysfunction in opioid use, and the mechanisms leading to opioid-induced vascular damage remain unknown. We hypothesized that exposure to exogenous opioids causes sex-specific vascular remodeling that will be more pronounced in female. Acknowledging the emerging roles of cofilins and extracellular signal-regulated kinases (ERKs) in mediating actin dynamics, we investigated the effects of morphine on these molecules. Twenty-four hour exposure to morphine increased inactivated cofilin and activated ERKs in resistance arteries from female mice, which may promote stress fiber over-assembly. We also performed continuous intraluminal infusion of morphine in pressurized resistance arteries from male and female mice using culture pressure myographs. We observed that morphine reduced the vascular diameter in resistance arteries from female, but not male mice. These results have significant implications for the previously unexplored role of exogenous opioids as a modifiable cardiovascular risk factor, especially in women.

Efficacy and Safety of Direct Oral Anticoagulants Versus Vitamin K Antagonists in the Treatment of Left Ventricular Thrombus: A Systematic Review and Meta-analysis.

BACKGROUND: Left ventricular thrombus (LVT) may develop in systolic heart failure or after acute myocardial infarction. The current recommendations support the use of vitamin K antagonists (VKAs) for the treatment of LVT. Limited data exist regarding the use of direct oral anticoagulants (DOACs) in patients with LVT. This meta-analysis aims to investigate the efficacy and safety of DOACs versus VKAs for LVT. METHODS: We performed a comprehensive literature search using PubMed, Embase, and Cochrane Library databases through November 2020 for all studies that evaluated the efficacy and safety of DOACs versus VKAs in patients with LVT. The primary outcomes were LVT resolution, overall thromboembolic events, and thromboembolic stroke. The secondary outcomes were major bleeding and all-cause mortality. Pooled risk ratio (RR) and 95% confidence intervals (CIs) were obtained by the Mantel-Haenszel method within a random-effects model. Heterogeneity was assessed by I2 statistic. RESULTS: A total of 11 studies including 2153 patients with LVT on anticoagulation (570 on DOACs vs. 1583 on VKAs) were included. LVT resolution was significantly higher in DOACs compared with VKAs [RR: 1.18 (95% CI: 1.04-1.35); P = 0.01, I2 = 25%]. However, no significant difference existed between DOACs and VKAs regarding overall thromboembolic events [RR: 1.10 (95% CI: 0.75-1.62); P = 0.61, I2 = 0%] and thromboembolic stroke [RR: 0.63 (95% CI: 0.39-1.02); P = 0.06, I2 = 0%]. Major bleeding [RR: 1.00 (95% CI: 0.66-1.51); P = 0.99, I2 = 4%] and all-cause mortality [RR: 0.84 (95% CI: 0.50-1.43); P = 0.53, I2 = 0%] were similar between the 2 groups. CONCLUSIONS: DOACs seem to be more efficacious in achieving LVT resolution compared with VKAs. However, there was no significant difference between the 2 groups in thromboembolic events, major bleeding, and all-cause mortality. Randomized controlled trials are needed to confirm our findings.

Supraventricular Tachycardia and Postural Orthostatic Tachycardia Syndrome Overlap: A Retrospective Study.

Postural orthostatic tachycardia syndrome (POTS) and supraventricular tachycardia (SVT) are disease states with distinctive features but overlapping clinical manifestations. Currently, studies on the presence of underlying SVT in patients with POTS are lacking. This retrospective study analyzed 64 patients [mean age: 43 years; 41 (61%) women] who had a POTS diagnosis and were found to have concomitant SVT during rhythm monitoring from September 1, 2013 to September 30, 2019 at our Syncope and Autonomic Disorders Clinic. The outcomes assessed were changes in disease severity, frequency of symptoms, heart rate, and blood pressure between before and after SVT ablation. The most frequent types of SVT noted on the electrophysiologic study were atrioventricular nodal reentrant tachycardia (57.81%), atrial flutter (29.68%), atrioventricular reentrant tachycardia (9.37%), atrial tachycardia (1.56%), and junctional tachycardia (1.56%). After SVT ablation, all 64 patients experienced an improvement in symptoms. Palpitations and lightheadedness experienced the most improvement after the procedure (72% vs. 31%; p < 0.001 and 63% vs. 22%; p < 0.001, respectively). There was a significant improvement in the resting heart rate (81.1 ± 12.8 vs. 75.8 ± 15.6 bpm; p < 0.002), but the orthostatic tachycardia on standing persisted (93.6 ± 16.5 vs. 77.3 ± 19.8 bpm; p = 0.14). Underlying SVT in patients with POTS can be missed easily. A strong suspicion and long-term ambulatory cardiac rhythm monitoring can help in diagnosing the condition.

FPR-1 (Formyl Peptide Receptor-1) Activation Promotes Spontaneous, Premature Hypertension in Dahl Salt-Sensitive Rats.

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Intrinsic Exercise Capacity and Mitochondrial DNA Lead to Opposing Vascular-Associated Risks.

Exercise capacity is a strong predictor of all-cause morbidity and mortality in humans. However, the associated hemodynamic traits that link this valuable indicator to its subsequent disease risks are numerable. Additionally, exercise capacity has a substantial heritable component and genome-wide screening indicates a vast amount of nuclear and mitochondrial DNA (mtDNA) markers are significantly associated with traits of physical performance. A long-term selection experiment in rats confirms a divide for cardiovascular risks between low- and high-capacity runners (LCR and HCR, respectively), equipping us with a preclinical animal model to uncover new mechanisms. Here, we evaluated the LCR and HCR rat model system for differences in vascular function at the arterial resistance level. Consistent with the known divide between health and disease, we observed that LCR rats present with resistance artery and perivascular adipose tissue dysfunction compared to HCR rats that mimic qualities important for health, including improved vascular relaxation. Uniquely, we show by generating conplastic strains, which LCR males with mtDNA of female HCR (LCR-mtHCR/Tol) present with improved vascular function. Conversely, HCR-mtLCR/Tol rats displayed indices for cardiac dysfunction. The outcome of this study suggests that the interplay between the nuclear genome and the maternally inherited mitochondrial genome with high intrinsic exercise capacity is a significant factor for improved vascular physiology, and animal models developed on an interaction between nuclear and mtDNA are valuable new tools for probing vascular risk factors in the offspring.

Candida albicans endocarditis involving a normal native aortic valve in an immunocompetent patient.

Fungal endocarditis, specifically from Candida species, is a rare but serious infection with a high mortality rate. Most cases occur in bioprosthetic or mechanical valves and are uncommon in native, structurally normal valves. When Candida endocarditis is detected and appropriate treatment is initiated earlier, there is an improvement in mortality. While the recommendation is usually to treat with a combination of surgery and antifungal medications, patient comorbidities may limit treatment options.

Microbiota are critical for vascular physiology: Germ-free status weakens contractility and induces sex-specific vascular remodeling in mice.

Commensal microbiota within a holobiont contribute to the overall health of the host via mutualistic symbiosis. Disturbances in such symbiosis is prominently correlated with a variety of diseases affecting the modern society of humans including cardiovascular diseases, which are the number one contributors to human mortality. Given that a hallmark of all cardiovascular diseases is changes in vascular function, we hypothesized that depleting microbiota from a holobiont would induce vascular dysfunction. To test this hypothesis, young mice of both sexes raised in germ-free conditions were examined vascular contractility and structure. Here we observed that male and female germ-free mice presented a decrease in contraction of resistance arteries. These changes were more pronounced in germ-free males than in germ-free females mice. Furthermore, there was a distinct change in vascular remodeling between males and females germ-free mice. Resistance arteries from male germ-free mice demonstrated increased vascular stiffness, as shown by the leftward shift in the stress-strain curve and inward hypotrophic remodeling, a characteristic of chronic reduction in blood flow. On the other hand, resistance arteries from germ-free female mice were similar in the stress-strain curves to that of conventionally raised mice, but were distinctly different and showed outward hypertrophic remodeling, a characteristic seen in aging. Interestingly, we observed that reactive oxygen species (ROS) generation from bone marrow derived neutrophils is blunted in female germ-free mice, but it is exacerbated in male germ-free mice. In conclusion, these observations indicate that commensal microbiota of a holobiont are central to maintain proper vascular function and structure homeostasis, especially in males.

Improved Model for Predicting the Free Energy Contribution of Dinucleotide Bulges to RNA Duplex Stability.

Predicting the secondary structure of RNA is an intermediate in predicting RNA three-dimensional structure. Commonly, determining RNA secondary structure from sequence uses free energy minimization and nearest neighbor parameters. Current algorithms utilize a sequence-independent model to predict free energy contributions of dinucleotide bulges. To determine if a sequence-dependent model would be more accurate, short RNA duplexes containing dinucleotide bulges with different sequences and nearest neighbor combinations were optically melted to derive thermodynamic parameters. These data suggested energy contributions of dinucleotide bulges were sequence-dependent, and a sequence-dependent model was derived. This model assigns free energy penalties based on the identity of nucleotides in the bulge (3.06 kcal/mol for two purines, 2.93 kcal/mol for two pyrimidines, 2.71 kcal/mol for 5'-purine-pyrimidine-3', and 2.41 kcal/mol for 5'-pyrimidine-purine-3'). The predictive model also includes a 0.45 kcal/mol penalty for an A-U pair adjacent to the bulge and a -0.28 kcal/mol bonus for a G-U pair adjacent to the bulge. The new sequence-dependent model results in predicted values within, on average, 0.17 kcal/mol of experimental values, a significant improvement over the sequence-independent model. This model and new experimental values can be incorporated into algorithms that predict RNA stability and secondary structure from sequence.