Endothelial progenitor cells delivered into the pericardial space incorporate into areas of ischemic myocardium.

OBJECTIVE: Our objective was to determine whether autologous endothelial progenitor cells (EPCs) delivered into the pericardial space will migrate to and incorporate into ischemic myocardium in a porcine model. BACKGROUND: Use of EPCs to enhance neovascularization and preserve myocardial function in ischemic tissue is undergoing intense scrutiny as a potential therapy. Delivery into the pericardial sac may overcome some of the limitations of currently employed cell delivery techniques. METHODS: EPCs were immunopurified from peripheral blood of Yorkshire pigs by selecting for the CD31 surface antigen, and adherent cells were cultured for 3-5 days. After myocardial ischemia was induced in the left anterior descending (LAD) artery, either autologous DiI (1,1'-dioctadecyl-1-3,3,3',3'-tetramethylindocarbocyanine perchlorate)-labeled EPCs (n=10) or serum-free medium (SFM; n=8) was delivered into the pericardial space using a percutaneous transatrial approach. Animals were sacrificed on Day 7 or 21. Echocardiography was performed at baseline, during ischemia, and on Day 7 in six SFM group animals and six EPC group animals. RESULTS: On Day 7, EPCs were identified in the left ventricular (LV) anterior wall or anterior septum in all six EPC-treated animals (cell density of 626 ± 122/mm(2)). On Day 21, EPCs were identified in the LV anterior wall or anterior septum in three of four EPC-treated animals (cell density of 267 ± 167/mm(2)). These cells showed dual staining for DiI and Bandeiraea simplicifolia lectin I (a marker of both native and exogenous endothelial cells). At the Day 7 follow-up, echocardiography demonstrated that fractional shortening in the EPC-treated group was 30.6 ± 3.4, compared with 22.6 ± 2.8 in SFM controls (P=.05). CONCLUSIONS: EPCs can migrate from the pericardial space to incorporate exclusively into areas of ischemic myocardium and may have favorable effects on LV function.

Conivaptan: promise of treatment in heart failure.

Conivaptan, the first vasopressin receptor antagonist approved by the FDA, is available for the treatment of hyponatremia in euvolemic and hypervolemic patients. The renin-angiotensin-aldosterone system is activated in heart failure (HF) causing clinical worsening. Arginine vasopressin levels are also elevated in HF. Conivaptan is an effective and FDA approved for the treatment of euvolemic and hypervolemic hyponatremia and may offer an extra treatment option in HF by targeting V(1a) and V(2) receptors. In this article we review the physiology, preclinical studies as well as the human clinical studies on the use of conivaptan and its potential and promise in the treatment of HF.

Therapeutic ultrasound in cardiology.

Ultrasound can be exploited to derive therapeutic results by using its bioeffects such as creation of mechanical vibrations, localized cavitations, microstream formation, physicochemical changes and thermal energy. Extensive in vitro and animal investigations during the last 2 decades have laid a foundation for ultrasound energy to be used for treatment purposes in various medical specialties. In the area of cardiovascular diseases, ultrasound could be used for thrombolysis, adjunct to coronary interventions, drug delivery, local gene transfer, and creating therapeutic lesions. The dispensation approaches to therapeutic ultrasound are varied, from the use of low- to medium-range frequency, low to focused high intensity, and catheter-based to external devices. Catheter-based ultrasound could be useful for intracoronary thrombolysis, and external ultrasound instrument with transcutaneous delivery could be of use in applications such as creation of myocardial lesions, peripheral vessel thrombolysis, and drug and gene delivery. Adjunct administration of microbubbles has been found to enhance thrombolysis, and drug and gene therapy. Ongoing studies strongly suggest that therapeutic ultrasound could have an important role in cardiovascular disorders associated with thrombosis, inflammation, atherosclerotic disease, and arrhythmias.

Recent role of imaging in the diagnosis of pericardial disease.

Noninvasive cardiac imaging techniques have made a striking impact on the evaluation and management of pericardial disorders. Two-dimensional and Doppler echocardiography are the methods of choice in the evaluation of pericardial effusion and cardiac tamponade. Magnetic resonance imaging, computed tomography, and transesophageal echocardiography are valuable in the assessment of pericardial thickness in suspected cases of constrictive pericarditis. Filling dysfunction associated with constrictive pericarditis is well demonstrated by Doppler flow velocity recordings of intracardiac flow jets, and pulmonary and hepatic venous flow streams. Tissue Doppler echocardiography, by which tissue velocity of myocardial regions and mitral annulus are analyzed, offers additional information in the differentiation of constrictive pericarditis and restrictive cardiomyopathy. Magnetic resonance imaging and computed tomography are the techniques of choice in the recognition of unusual disorders such as pericardial cysts, tumors invading the pericardium, and congenital absence of pericardium. Noninvasive imaging aids not only in the diagnosis of pericardial diseases, but also in the guidance of optimal therapy.