Experimental & Clinical Cardiology最新文献

Atrial fibrillation (AF) represents the most common sustained cardiac arrhythmia in patients with heart failure (HF). AF in HF patients is associated with worsening of symptoms and also results in a substantial increase in mortality. Although HF patients in sinus rhythm have a better outcome than patients with AF, several randomized studies investigating pharmacological rhythm control versus rate control have shown no advantage of one strategy over the other in terms of patient outcomes. Catheter-based ablation therapy is a newer therapeutic option with a rapidly evolving and changing role in the management of this arrhythmia. In the present review, the authors discuss the epidemiology, pathophysiology and prognostic significance of AF in patients with HF. Exclusively addressed are studies investigating catheter-based ablation for rhythm-control and rate-control therapies in the management of AF in HF patients.

The present article reports a case involving a 58-year-old man without cardiovascular risk factors who was admitted to hospital with acute coronary syndrome. Coronary angiography revealed high-grade arteriosclerotic stenosis of the mid-left anterior descending coronary artery and 80% proximal intermediate branch stenosis, which were treated using three drug-eluting stents. Churg-Strauss syndrome was diagnosed based on the patient's history of asthma, sinusitis, eosinophilia, nasal polyps, transient radiological pulmonary infiltrations and transient paresthesia over the left tibia, and eosinophilic pericardial effusion and eosinophilic infiltrations revealed in a myocardial biopsy. Treatment with prednisone was initiated, followed by treatment with cyclophosphamide. Eosinophil levels returned to normal after nine days of treatment. There is evidence that Churg-Strauss syndrome may promote arteriosclerosis.

Mild aortic root dilation is relatively common in patients with acromegaly and does not usually require surgical intervention. A case involving a 27-year-old acromegalic woman who presented with heart failure and gross aortic root dilation that was successfully treated with a composite aortic graft prosthesis is described.

Infective endocarditis is one of three common cardiac infections in the United Kingdom, in addition to myocarditis and pericarditis, with a reported incidence of 1.7 to 6.2 cases per 100,000 patient years. Infective endocarditis can often have serious consequences and a wide variety of organisms may be the causative pathogen. There are little published data regarding the exact spectrum of organisms that cause endocarditis in the United Kingdom and whether organisms such as streptococci still dominate. In the present study, all cases of endocarditis at the authors' institution, representing a typical nontertiary centre, were retrospectively examined and audited to provide a snapshot of the organism spectrum in these patients. The cases of more than 120 patients who were coded as having endocarditis by the institution's clinical coding department during the period between December 2000 and January 2011 were examined. Microbiological tests and clinical case notes of all patients were reviewed. Of the 101 patients diagnosed with and treated for endocarditis, 64 were male, with a mean age of 60.57 years. The most common organisms identified were Streptococcus species (31%), Staphylococcus aureus (27%) and Enterococcus faecalis (21%). The organisms with the highest associated mortality rate were S aureus and the 'other organism' group, which included non-HACEK group (Haemophilus species, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens and Kingella species) pathogens such as Candida albicans. Streptococcus species and S aureus remain the main cause of endocarditis in a typical hospital setting in the United Kingdom, although in a smaller proportion of cases than historical data suggests. Overall, mortality remains high, and the clinician should remain vigilant to endocarditis in any patient with a positive blood culture because the number of cases of endocarditis caused by less typical organisms are increasing.

Background: An inflammatory response and systemic oxidative stress are directly caused by coronary artery bypass grafting (CABG) surgery. Cytokines, such as interleukin (IL) 1β, IL-6 and tumour necrosis factor-α (TNF-α), can also be stimulated. Reducing the release of pro-inflammatory cytokines plays an important role in limiting the postoperative inflammatory response. Silymarin has strong anti-inflammatory, antioxidant and cytoprotective properties.

Objective: To investigate the protective anti-inflammatory and antioxidant properties of silymarin against the inflammation and oxidative stresss inherent to CABG surgery.

Methods: Of the 102 patients undergoing elective first-time CABG surgery that were recruited, 50 (49.02%) received silymarin treatment and 52 (50.9%) were controls. Plasma cytokine levels (IL-1β, IL-6 and TNF-α) were measured preoperatively, 6 h and 24 h after CABG surgery. C-reactive protein (CRP) levels, trolox equivalent antioxidant capacity (TEAC) and glutathione (GSH) and malondialdehyde (MDA) levels were analyzed.

Results: Postoperative cytokine levels in the silymarin group were significantly lower compared with preoperative levels, and were significantly lower compared with postoperative control group levels. The area under the curve for cytokines and CRP for the silymarin group were significantly lower compared with preoperative levels, and were significantly lower compared with postoperative control group levels. Postoperative levels of TEAC and MDA in the silymarin-treated group were significantly lower than in the control group. GSH levels were significantly elevated in the silymarin group compared with control. No side effects or mortality were associated with the use of silymarin.

Conclusion: The anti-inflammatory and antioxidant effects of silymarin treatment provided protection against reperfusion injury and inflammation after CABG surgery.

Background: Coronary artery disease (CAD) occurs at an earlier age in South Asians compared with other ethnic groups. Infection and inflammation show a positive association with the disease.

Objective: To investigate the association of infection and inflammatory markers with premature CAD in the Indian Atherosclerosis Research Study population.

Methods: Antibody titres for Chlamydia pneumoniae, cytomegalovirus (CMV), Helicobacter pylori, herpes simplex virus and levels of interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), fibrinogen and secretory phospholipase A2, were measured in 866 individuals (433 CAD patients and matched controls). All individuals were followed-up for recurrent cardiac events for four years. ANOVA was used to study the association of infection and inflammation with CAD.

Results: The present study found that the odds of CAD occurrence was 2.42 (95% CI 1.26 to 4.64; P<0.008), with all four infections and increased in the presence of hsCRP (OR 4.67 [95% CI 1.43 to 15.25]); P=0.011). Only anti-CMV antibody levels were a significant risk factor for CAD occurrence (OR 2.23 [95% CI 1.20 to 4.15]; P=0.011) and recurrent cardiac events (OR 1.94 [95% CI 0.85 to 4.45]; P=0.015). Mean values of the inflammatory biomarkers IL-6 (P=0.035), fibrinogen (P=0.014), hsCRP (P=0.010) and secretory phospholipase A2 (P=0.002) increased with CMV antibody levels. Incorporating hsCRP and IL-6 in the risk prediction models significantly increased the OR to 2.56 (95% CI 1.16 to 5.63; P=0.019) with a c statistic of 0.826.

Conclusions: Pathogen burden, especially CMV infection in combination with inflammatory markers, is a significant predictor of CAD risk in the young Indian population.

Lung tumours are the leading metastatic cancers that spread to the heart through direct invasion, and rarely extend into the chambers of the left side of the heart via pulmonary veins. A case of primary lung sarcoma involving a patient who presented with dyspnea and fatigue is reported. This sarcoma extended from the lung into the left atrium via (a/the) pulmonary vein. Chemotherapy and radiotherapy were recommended. Surgery was not considered due to high risk and the advanced stage of the tumour.

Background: The critical role of microRNAs (miRNAs) in the global control of gene expression in the heart has recently been postulated; however, the mechanisms of miRNA regulation in cardiac pathology are not clear.

Objective: To evaluate the levels of miR-1, miR-208a and miR-29a expressed in neonatal rat cardiomyocytes during anoxia-reoxygenation (AR).

Methods: Reverse transcription coupled with real-time polymerase chain reaction was used to evaluate the level of mature and immature miRNAs in cardiomyocyte culture during AR.

Results: THE INITIAL LEVELS OF THE MATURE AND IMMATURE MIRNAS WERE DIFFERENT: mature - miR-1 7.46±4.440, miR-208a 0.02±0.015 and miR-29a 5.60±2.060; immature - miR-1 0.02±0.007, miR-208a 0.05±0.029 and miR-29a 0.01±0.008. The most prominent changes were observed for immature miRNAs during AR, with immature miR-1 and miR-29a expressed at significantly higher levels during remote reoxygenation (AR [0.5 h/24 h]) compared with control, while the level of expressed immature miR-208a was significantly decreased during acute reoxygenation (AR [0.5 h /1 h]) and returned to control levels during remote reoxygenation (AR [0.5h /24 h]). Also, the ratios of mature to immature miRNAs were significantly increased during acute reoxygenation for miR-1 and miR-208a, returning to control levels during remote reoxygenation, while for miR-29a, this ratio had the progressive tendency to decrease under AR.

Conclusion: The discordance between the estimated levels of mature and immature miRNA during AR supports the hypothesis that transcriptional and post-transcriptional regulatory mechanisms at the miRNA level play a role in the response of cardiomyocytes to AR, and could be a contributing factor in the differential resistance of cardiomyocytes to AR.

Background: Although earlier studies demonstrated endothelial dysfunction and systemic inflammation in patients with microvascular angina (MVA), the correlations between flow-mediated dilation (FMD), high-sensitivity C-reactive protein (hsCRP) levels and Duke treadmill score (DTS), a comprehensive index representing the severity of ischemia, have not been elucidated in this setting.

Objective: To explore the possible relationships among brachial FMD, serum hsCRP levels and DTS in MVA patients.

Methods and results: A total of 89 subjects with chest pain and a normal coronary angiogram were studied. The exercise treadmill test (ETT) was performed using the Bruce protocol for calculating the DTS. Brachial FMD and serum hsCRP levels were measured. The mean (± SD) brachial FMD was 5.45±2.24% in the group with positive ETT and 8.19±2.78% in the group with a negative ETT (P<0.001). Mean serum hsCRP levels were significantly higher in the group with positive ETT than in the group with negative ETT (4.93±1.63 mg/L versus 3.41±1.65 mg/L; P<0.001). Brachial FMD and serum hsCRP levels showed significant differences among the three groups according to DTS risk stratification. The DTS was positively correlated with FMD (r=0.532; P<0.001) and negatively correlated with hsCRP level (r= 0.461; P<0.001).

Conclusions: Brachial FMD and serum hsCRP levels may be associated with DTS in patients with MVA.