Comparison of the electrophysiological properties of the pulmonary veins between paroxysmal and persistent atrial fibrillation

Background

The role of the pulmonary veins (PVs) as triggers in atrial fibrillation (AF) is well-known; however, their detailed electrophysiological properties have not been thoroughly examined.

Objective

This study aimed to investigate the electrophysiological properties of the PVs between paroxysmal AF (pAF) and persistent AF (perAF).

Methods

Prior to catheter ablation in patients with pAF (n = 51) and perAF (n = 41), a voltage map of the left atrium and PVs was created under sinus rhythm, and the area of the myocardial sleeves in the PVs and their electrophysiological characteristics, including the pacing threshold and effective refractory period (ERP), were compared between the two groups.

Results

Compared with perAF, the myocardial sleeves of PVs for pAF were significantly larger for all PVs. The ERP for perAF was significantly shorter than that for pAF for all PVs. The pacing threshold for perAF was significantly higher than that for pAF for the right and left superior PVs.

Conclusion

In patients with perAF, a decrease in the normal myocardial sleeves and a shortening of the ERP were observed for all PVs. Those changes in the electrophysiological properties of the PVs might be related to the persistence of AF.

Diagnostic and Therapeutic Strategies for Stable Coronary Artery Disease Following the ISCHEMIA Trial

Until recently, coronary revascularization with coronary artery bypass grafting or percutaneous coronary intervention has been regarded as the standard choice for stable coronary artery disease (CAD), particularly for patients with a significant burden of ischemia. However, in conjunction with remarkable advances in adjunctive medical therapy and a deeper understanding of its long-term prognosis from recent large-scale clinical trials, including ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), the approach to stable CAD has changed drastically. Although the updated evidence from recent randomized clinical trials will likely modify the recommendations for future clinical practice guidelines, there are still unresolved and unmet issues in Asia, where prevalence and practice patterns are markedly different from those in Western countries. Herein, the authors discuss perspectives on: 1) assessing the diagnostic probability of patients with stable CAD; 2) application of noninvasive imaging tests; 3) initiation and titration of medical therapy; and 4) evolution of revascularization procedures in the modern era.

Premature Acute Myocardial Infarction in a Young Patient With Sitosterolemia

Sitosterolemia is a rare, inherited, autosomal recessive disorder of lipid metabolism characterized by increased levels of plant sterols, such as sitosterol and campesterol, xanthomas, and accelerated atherosclerosis. In a 15-year-old boy exhibiting ST-elevation acute myocardial infarction, lipid panels, including plant sterol, and genetic testing for the ATP-binding cassette sub-family G member 5 (ABCG5) gene mutation, confirmed the diagnosis of sitosterolemia. A comprehensive lipid panel and genetic testing should be considered in patients with premature coronary artery disease to prevent disease progression through dietary and pharmacologic interventions specific to sitosterolemia.

Contemporary Management of Stable Coronary Artery Disease - Implications of the ISCHEMIA Trial

Coronary artery disease (CAD) remains a leading cause of mortality and morbidity in developed countries. Although urgent revascularization is the cornerstone of management of acute coronary syndrome (ACS), for patients with stable CAD recent large-scale clinical trials indicate that a mechanical 'fix' of a narrowed artery is not obviously beneficial; ACS and stable CAD are increasingly recognized as different clinical entities. We review the perspectives on (1) modifying the diagnostic pathway of stable CAD with the incorporation of modern estimates of pretest probability, (2) non-imaging evaluations based on their availability, (3) the optimal timing of invasive coronary angiography and revascularization, and (4) the implementation of medical therapy during the work-up.

Acute Myocardial Infarction in an Adolescent Receiving Anagrelide for Essential Thrombocythemia with Underlying Persistent Coronary Endothelial Dysfunction

Essential thrombocythemia (ET) is a Philadelphia chromosome-negative myeloproliferative disorder that is characterized by the overproduction of platelets and a marked increase in the numbers of mature megakaryocytes present in the bone marrow. Thrombohemorrhagic disorders are major morbidities of ET, especially those with mutations in the gene encoding Janus kinase 2 (JAK2). In this study, we report the case of an 18-year-old patient with ET carrying JAK2 mutation who developed acute ST-elevation myocardial infarction (STEMI) 5 months after a commencement of anagrelide. Coronary endothelial dysfunction confirmed by positive acetylcholine provocation test lasted a year after the occurrence of STEMI. Furthermore, intracoronary imaging using optical coherence tomography demonstrated non-atheromatous intimal fibrosis possibly due to chronic endothelial damage. The coronary pathologies reflected chronic change potentially associated with properties of ET and JAK2 mutation in addition to hyperviscosity. These observations suggest that the side effect of anagrelide in our patient was considered causative, while underlying chronic endothelial dysfunction and adverse endothelial remodeling may be predisposing factors to his fatal cardiovascular events.

Mid-term predictive value of calciprotein particles in maintenance hemodialysis patients based on a gel-filtration assay

BACKGROUND AND AIMS

Calciprotein particles (CPPs), nano-aggregates containing fetuin-A-bound calcium-phosphate, are associated with aortic stiffness and coronary calcification in maintenance hemodialysis patients. A novel gel-filtration assay can detect low-density small CPPs, which are actually a major form of circulating CPPs in vivo. We sought to investigate whether circulating CPP levels measured by gel-filtration method would accurately predict hard endpoints in maintenance hemodialysis patients.

METHODS

This study used a prospective, multicenter, longitudinal, and observational design. One-hundred eight patients enrolled in this study were followed-up for about 2 years. We reported all-cause death and cardiovascular events, which included major adverse cardiac, cerebrovascular, and limb events.

RESULTS

Kaplan-Meier analysis showed no significant difference between patients with the higher (>median) and lower (<median) CPP levels with regard to all-cause death. However, the higher CPP group showed a higher incidence of cardiovascular events (log-rank test χ² = 4.41, p = 0.036). Univariate Cox regression analysis revealed that CPP levels were not associated with all-cause death, but were significantly associated with higher incidence of cardiovascular events (hazard ratio (HR) 1.03, 95% confidence interval (CI) [1.02-1.05], p < 0.001) for every thousand CPP increase. Multivariate Cox regression analysis revealed that CPP levels were not associated with all-cause death, but were independently associated with cardiovascular events (HR 1.03, 95% CI [1.01-1.04], p < 0.001) for every thousand CPP.

CONCLUSIONS

This finding suggests a potential predictive value of CPPs in maintenance hemodialysis patients.

Tranexamic Acid Controlled Chronic Disseminated Intravascular Coagulation Associated with Aortic Dissection and Patent False Lumen for Three Years

The management of chronic disseminated intravascular coagulation (DIC) caused by aortic dissection has not yet been established. Even in cases where surgical correction is performed, therapeutic control of systemic hemorrhaging is still required. We herein report the successful treatment of a case of aortic dissection with a patent false lumen using tranexamic acid for acute exacerbation of chronic DIC. Oral administration of 1,500 mg tranexamic acid per day stabilized the coagulative and fibrinolytic parameters and relieved bleeding tendencies with no side effects. Heparin was administered periodically for the management of hemodialysis. This favorable result continued for up to 3 years.

A Novel Index Using Ankle Hemodynamic Parameters to Assess the Severity of Peripheral Arterial Disease: A Pilot Study

In peripheral arterial disease (PAD) of the lower extremities, the presence of flow-limiting stenoses can be objectively detected by the ankle-brachial index (ABI). However, the severity of ischemic symptoms is not necessarily associated with the ABI value. Atherosclerotic plaque in lower extremity PAD induces ankle arterial stiffness and reduces ankle vascular resistance, which may decrease ankle blood flow and cause ischemic symptoms. We hypothesized that the ankle hemodynamic index (AHI), defined as the ratio of ankle arterial stiffness to ankle vascular resistance, could be used to assess the blood supply deficiency in a diseased lower limb in patients with PAD. The 85 consecutive patients with PAD who were retrospectively analyzed in this study had Rutherford grade 1 to grade 6 ischemia diagnosed as PAD and significant stenotic lesions (>50% diameter stenosis) of the lower extremity on contrast angiography. The AHI was calculated as the product of the ankle pulse pressure and the ratio of heart rate to ankle mean arterial pressure (ankle pulse pressure × heart rate/ankle mean arterial pressure). The Rutherford grade was significantly correlated with the AHI (r = 0.50, P < 0.001), but not with the ABI (r = 0.07, P = 0.52). Multiple ordinal regression analysis showed that anemia (odds ratio 0.66, P = 0.002) and AHI (odds ratio 1.04, P = 0.02) were independently associated with Rutherford grade. Our study shows that AHI, a novel parameter based on the ABI measurement, is well correlated with ischemic symptoms, and may be a useful means to assess the arterial blood supply of the lower extremities of patients with PAD.

Successful Management of a Patient with Refractory Ventricular Fibrillation (VF) due to Acute Myocardial Infarction (AMI) and Lung Injury by Transition from Percutaneous Cardiopulmonary Support (PCPS) to Veno-Venous Extracorporeal Membrane Oxygenation (ECMO)

A 69-year-old man was admitted to our hospital with cardiopulmonary arrest. Percutaneous cardio-pulmonary support (PCPS) using the right femoral artery and vein was initiated, because ventricular fibrillation continued. Although we succeeded in defibrillation after percutaneous coronary intervention (PCI), a chest radiograph indicated a pneumothorax in the right lung and a pulmonic contusion in the left lung caused by cardiopulmonary resuscitation. Two days after PCI, partial pressure of arterial oxygen (PaO2) from the right radial artery suddenly decreased, and his cardiac function showed improvement on an echocardiogram. To avoid additional brain damage, we converted the treatment to veno-venous extracorporeal membrane oxygenation by changing the blood returning site of PCPS from the right femoral artery to the right jugular vein. Thereafter, the patient's PaO2 level gradually improved.