- Electrophysiological Consequences of Acute Regional Ischemia/Reperfusion in Neonatal Rat Ventricular Myocyte Monolayers
- Direction of Preoperative Ventricular Shunting Affects Ventricular Mechanics After Tetralogy of Fallot Repair
- National Practice Patterns for Management of Adult Congenital Heart Disease: Operation By Pediatric Heart Surgeons Decreases In-Hospital Death
- Vascular Endothelial Function and Leisure-Time Physical Activity in Adolescents
- Predominance of Heart Failure in the Heart of Soweto Study Cohort: Emerging Challenges for Urban African Communities
- Morphology of Exertion-Triggered Plaque Rupture in Patients With Acute Coronary Syndrome: An Optical Coherence Tomography Study
- Nonrandomized Comparison of Coronary Artery Bypass Surgery and Percutaneous Coronary Intervention for the Treatment of Unprotected Left Main Coronary Artery Disease in Octogenarians
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Electrophysiological Consequences of Acute Regional Ischemia/Reperfusion in Neonatal Rat Ventricular Myocyte Monolayers
The present study shows that acute ischemia/reperfusion, created by placing a glass coverslip over a portion of a cultured neonatal rat ventricular myocyte monolayer, exhibits the major electrophysiological hallmarks of acute ischemia/reperfusion, including spontaneous arrhythmias that are observed in intact 3-dimensional hearts subjected to coronary occlusion. Because of the much simpler geometry of the ischemic zone, border zone, and nonischemic zone, as well as the ability to image cellular events at high resolution, this 2-dimensional model will be useful for studying the cellular basis of electrophysiological alterations and arrhythmias during acute ischemia/reperfusion. In addition, it may prove to be useful for evaluating antiarrhythmic and cardioprotective interventions. See p 2330.
Direction of Preoperative Ventricular Shunting Affects Ventricular Mechanics After Tetralogy of Fallot Repair
Tetralogy of Fallot is a spectrum of disease, from patients with severe pulmonary blood flow restriction to patients with simple ventricular septal defect physiology and pulmonary overcirculation. Given its anatomic features, tetralogy of Fallot is often thought of as a disease of the right side of the heart alone, with the assumption of a normal left heart. However, this study of intraoperative left ventricular (LV) mechanics demonstrated depression of LV systolic and diastolic function in all patients after tetralogy of Fallot repair. Mechanisms of this depressed function may involve imperfect myocardial protection and/or mechanical factors related to the ventricular septal defect patch. The present study also demonstrated that effects of surgery on ventricular geometry and loading varied with the direction of blood flow through the ventricular septal defect. LV preload from patients with predominantly right-to-left shunts increased after repair, but preload decreased in patients with simple ventricular septal defect physiology. These differences have clinical implications for the treatment of low cardiac output in the postoperative period. The unloaded LV produced by closure of left-to-right shunts should respond favorably to volume administration, but closure of right-to-left shunts increases LV preload, which suggests inotropes as the intervention of choice. This study looked only at the immediate effects of tetralogy of Fallot repair on the LV. Further studies are needed to define the relevance of these changes to long-term outcomes. See p 2338.
National Practice Patterns for Management of Adult Congenital Heart Disease: Operation By Pediatric Heart Surgeons Decreases In-Hospital Death
Because of the improved outcomes for congenital heart surgery in the neonatal period, there are an increasing number of grown-up patients living with congenital heart disease (GUCH). Many GUCH patients, however, often require ongoing specialized care and surgical intervention, and despite the notion of adulthood, GUCH patients still offer unique challenges with respect to physiology and anatomic complexity for surgeons unfamiliar with congenital heart disease. Because of these unique challenges that characterize GUCH, there has been a growing focus on developing so-called adult congenital centers dedicated to the care of this growing population. Despite these initiatives, however, surgery for GUCH patients is still frequently performed by surgeons without specialization in pediatric heart surgery. Our study defines the national practice patterns for GUCH care in the United States and demonstrates that in-hospital mortality rates are significantly lower when operation is performed by specialized pediatric heart surgeons. The survival advantage increases as an individual surgeon’s annual percentage of pediatric heart operations increases. Furthermore, our study shows a reduction in resource use associated with operation by surgeons performing a higher annual percentage of pediatric heart operations. These data suggest that selective referral of GUCH patients to centers with specialized pediatric heart surgeons will reduce in-hospital death rates and improve the value of delivered care. See p 2345.
Vascular Endothelial Function and Leisure-Time Physical Activity in Adolescents
The onset of cardiovascular diseases lies in childhood. Impairment of arterial endothelial function is an important early observation in the atherosclerotic process. Brachial artery flow-mediated dilatation, a marker of systemic arterial endothelial function, can be measured with a feasible noninvasive ultrasound method already in childhood. In overweight and obese children and adolescents, exercise training improves endothelial function. Our results in adolescents representing the general population further suggest that leisure-time physical activity beneficially affects endothelial function. This effect was clearly found in boys, and with the same level of physical activity, girls experience a similar increase in maximum flow-mediated dilatation. Keeping in mind that physical activity also has several other positive health effects, clinicians should discuss physical activity habits with children and adolescents. Especially with sedentary children, enjoyable ways to be physically more active should be given attention. In addition to encouraging physical activity in children, clinicians could advise parents to exhibit a physically active role model. See p 2353.
Predominance of Heart Failure in the Heart of Soweto Study Cohort: Emerging Challenges for Urban African Communities
In 1 of the largest studies of heart failure (HF) in Africa, we studied 844 de novo cases in Soweto, South Africa. The results challenge a number of previous assumptions regarding the natural history of HF in Africa. Compared with more affluent countries, there was a higher prevalence of women (57%), and patients were younger (the mean age was 55±16 years.) The unexpectedly high burden of HF was attributed to a combination of etiologies, with the expected cases of hypertensive HF, idiopathic dilated cardiomyopathy, and HF due to structural valve disease supplemented by right HF and ischemic heart failure. These data have important clinical and public health implications for urban African and other communities in epidemiological transition where old and new forms of HF will emerge. Treatment strategies need to keep pace with the changing etiology of HF, and preventative strategies need focus on both old (eg, late recognition of rheumatic heart disease) and new antecedents (eg, atherosclerosis) of HF. Hypertension, in particular, represents a traditional antecedent for HF in Africa that will gain even more clinical importance as a preventative target. Significantly, we found a surprisingly high burden of right HF (either in isolation or in combination with left HF). The increasing burden of HF in vulnerable populations in Africa and beyond will necessitate the development of relatively inexpensive but effective programs of care that provide treatments adapted to the local healthcare system and the specific population. See p 2360.
Morphology of Exertion-Triggered Plaque Rupture in Patients With Acute Coronary Syndrome: An Optical Coherence Tomography Study
Plaque rupture and secondary thrombus formation play key roles in the onset of an acute coronary syndrome. To prevent acute coronary syndrome events, many studies have focused on rupture-prone plaques. Until recently, thin-cap fibroatheromas proposed by pathological studies and computational models were considered to be the most rupture-prone plaques. The data from the present study suggest that thin-cap fibroatheromas would be predisposed to rupture, both at rest and during the patient’s day-to day activity. Inflammation aggressively participates in the process of plaque instability, as suggested by the negative correlation between thickness of ruptured caps and high-sensitivity C-reactive protein levels. Furthermore, the data suggest that in the clinical setting, some plaque ruptures may occur in thick fibrous caps (70 to 140 μm) depending on exertion levels. Theses findings are consistent with new 3D finite-element models. Therefore, the present study suggests that broader thinking may be called for in the area of the mechanism of plaque rupture. Further investigation is required into not only thin-cap atheroma but also thick-cap atheroma in the clinical setting. See p 2368.
Nonrandomized Comparison of Coronary Artery Bypass Surgery and Percutaneous Coronary Intervention for the Treatment of Unprotected Left Main Coronary Artery Disease in Octogenarians
Percutaneous coronary intervention (PCI) has emerged as an alternative to coronary bypass graft surgery (CABG) for the treatment of unprotected left main coronary artery (LMCA) disease in the stent era. However, no studies to date have evaluated the results of PCI for the treatment of LMCA in octogenarians despite the fact that a growing number of octogenarian patients with LMCA disease estimated to be at high or prohibitive surgical risk are being proposed for PCI in the belief that it is a lower-risk alternative to CABG. This study included 249 consecutive patients ≥80 years of age with LMCA disease who underwent coronary revascularization (PCI, 104 patients; CABG, 145 patients) in our center. Major adverse cardiac and cerebrovascular events were evaluated at 23±16 months of follow-up. Patients who underwent PCI were older (85 versus 82 years of age) and exhibited higher-risk baseline characteristics (mean EuroSCORE, 9.5) than CABG patients. A propensity score analysis was performed to adjust for baseline differences between groups. CABG was associated with a higher rate of perioperative complications (atrial fibrillation, major bleeding, acute renal failure) and longer hospital stay. At follow-up, there was no statistical difference in the occurrence of cardiac death or myocardial infarction (CABG, 30.3%; PCI, 34.6%) and major adverse cardiac and cerebrovascular events (CABG, 35.2%; PCI, 43.3%) between CABG and PCI patients. In this single-center, nonrandomized study, there were no significant differences in cardiac death or myocardial infarction and major adverse cardiac and cerebrovascular events between CABG and PCI for the treatment of LMCA in octogenarians after a mean follow-up of 2 years. This study provides relevant information on the clinical management of LMCA disease in octogenarian patients and suggests that PCI is a reasonable strategy for the treatment of this highly challenging subset of patients. Randomized studies comparing both revascularization strategies in this high-risk coronary population are warranted. See p 2374.
- Vascular Endothelial Function and Leisure-Time Physical Activity in Adolescents
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