Strategy of pacemaker and electrode replacement for superior vena cava stenosis.

Cardiac implantable devices are commonly used for superior vena cava stenosis, but there have been few reports of electrode replacement in the stenosed superior vena cava. A 73-year-old man was diagnosed with second-degree type II atrioventricular block and a permanent dual-chamber, rate-modulated pacing pacemaker was implanted 10 years previously. Because of depletion of the pacemaker battery and an increase in the ventricular pacing threshold, replacement of the pacemaker and ventricular electrode was required. During the operation, we found that the patient had severe superior vena cava stenosis on angiography, and this caused obstruction when a common guidewire was used to pass through the superior vena cava. After attempting various methods, we successfully passed through the vascular stenosis with a super slide guidewire and a long sheath, and completed replacement of the pacemaker and ventricular electrode. We summarize the related literature of superior vena cava stenosis related to a cardiac implantable device, and discuss the replacement strategy of this complication and other treatment options.

Mechanisms underlying direct actions of hyperlipidemia on myocardium: an updated review.

Hyperlipidemia is a common metabolic disorder and one of risk factors for cardiovascular disease. Clinical studies have shown that hyperlipidemia increases the risk of non-ischemic heart failure, while decreasing serum lipids can reverse heart dysfunction. Apart from indirectly affecting the function of the heart by promoting the development of atherosclerosis, hyperlipidemia also affects the systolic function and cardiac electrophysiological response of the heart directly, which may be related to gradual accumulation of cardiac lipids and consequent systemic oxidative stress, proinflammatory state and mitochondrial dysfunction. However, the mechanism underlying direct effects of hyperlipidemia on the heart are not fully understood. In this review, we provide an updated summary of recent experimental and clinical studies that focus on elucidating the mechanisms of the action of hyperlipidemia on cardiac function, the relationship between heart failure and serum lipids, and protective effects of lipid-lowering drugs on the heart. The exciting progress in this field supports the prospect of guiding early protection of the heart to benefit the patients with chronic hyperlipidemia and familial hyperlipidemia.

Chronic Unpredictable Mild Stress Causing Cardiac and Thoracic Spinal Cord Electrophysiological Abnormalities May Be Associated with Increased Cardiac Expression of Serotonin and Growth-Associated Protein-43 in Rats.

BACKGROUND: The aim of this study was to investigate the potential mechanisms by which chronic unpredictable mild stress (CMS) might induce cardiovascular disease. METHODS: Twenty male Sprague-Dawley rats (weighing 180-250 g) were divided into the CMS group (CMS for 3 weeks) and control group (n = 10/group). Sucrose solution consumption, sucrose solution preference rate, and the open field test (horizontal and vertical movements) were used to confirm the establishment of the CMS model. Heart rate was determined in Langendorff-perfused hearts, and field action potential duration (FAPD) was measured in cardiac atrial tissue, cardiac ventricular tissue, and thoracic spinal cord segments 1-5. The expressions of serotonin (5-HT) and growth-associated protein-43 (GAP-43) in cardiac ventricular tissue were analyzed using immunohistochemistry and immunofluorescence. RESULTS: Compared with the control group, sucrose solution consumption, sucrose solution preference rate, horizontal movement, and vertical movement were significantly lower in the CMS group (P < 0.01). The CMS group exhibited significant decreases in atrial and ventricular FAPDs (P < 0.05), as well as significant increases in heart rates (P < 0.05) and T1-5 spinal cord FAPD (P < 0.01), as compared with the control group. The expressions of 5-HT and GAP-43 in cardiac ventricular tissue were significantly higher in the CMS group than in controls (P < 0.01). CONCLUSIONS: CMS causes cardiac and T1-5 spinal cord electrophysiological abnormalities as well as increased cardiac expression of 5-HT and GAP-43, indicating that CMS could potentially increase the risk of cardiovascular disease.

Adiponectin as a potential therapeutic target for the treatment of restenosis.

Restenosis is a pathologic re-narrowing of a coronary artery lesion after mechanical injury. Its pathophysiological mechanisms have not been fully elucidated at present, but are thought to include inflammation, vascular smooth muscle cell (VSMC) proliferation, and matrix remodeling, beginning with insufficient endothelium healing. Restenosis presents with angina symptoms or acute coronary syndromes and lead to a revascularization, either with coronary artery bypass or repeat percutaneous coronary intervention. Some studies have reported that hypoadiponectinemia has been an independent risk factor for the onset of acute coronary syndromes and restenosis. Accumulating evidence shows that low concentrations of adiponectin may be involved in impairing endothelium functions, inflammation, and VSMC proliferation that lead to restenosis. Preclinical studies have proven that adiponectin promotes endothelium healing, effectively inhibits inflammation, and maintains contractile phenotypes of VSMCs, indicating that it may be developed as a new therapeutic target for the treatment of restenosis.

Left atrial myxoma complicated with multi-system embolization.

BACKGROUND: Atrial myxoma accounts for approximately 50% of all cardiac tumors. The majority of myxomas are located in the left atrium and present variable clinical manifestation. CASE PRESENTATION: A young man was transferred to our hospital with sudden onset of resting pain, pallor and numb in right leg. An atrial mobile mass was detected by transthoracic echocardiography. Anticoagulant and antithrombotic therapy were administered, a timely surgery was performed and the mass was confirmed as a myxoma. The patient did not discharge any discomfort post-operation. CONCLUSION: For patients with atrial myxoma, early diagnosis is essential, anticoagulant or antithrombotic therapy and surgery have a great importance to prevent further embolism.

[Therapeutic effect of deoxyribonucleotidum on acute viral myocarditis].

OBJECTIVE: To evaluate the therapeutic efficacy of deoxyribonucleotidum in treatment of acute viral myocarditis. METHODS: Eighty-eight patients with acute viral myocarditis were randomized equally into therapeutic group and control group. Patients in the control group were treated with routine treatment and those in the therapeutic group were given deoxyribonucleotidum in addition to routine treatment. After 4 weeks, the total efficacy rate and median time of symptom disappearance were compared between the two groups. RESULTS: The total efficacy rate in the control and therapeutic groups was 79.54% and 95.45% (P=0.049), and the median time of symptom disappearance was 9.5 days and 6.5 days, respectively (P=0.035). Hypotension and mild dizziness were found in 2 patients in the therapeutic group without other severe side effects. CONCLUSION: Deoxyribonucleotidum can improve the therapeutic effect for acute viral myocarditis.