Effect of phentolamine on myocardial extracellular matrix of cardiac remodeling in rats

Objective:To study the effects of phentolamine on myocardial extracellular matrix of cardiac remodeling induced by norepinephrine in rats.Methods:24 SD rats were divided into 3 groups randomly:control groups,norepinephrine groups(model groups),norepinephrine +phentolamine groups(treatment groups).Echocardiography was used to detect changes in cardiac structure and function,the level of collagen volume fraction(CVF) and hydroxy-proline as well as collagen content were determined in myocardial tissue,matrix metalloproteinases-2 and collagen Ⅰin myocardial tissue were localized by immunohistochemitry.Results:Compared with control groups,left ventricular hypertrophy in the model group rats,the livdioxyproline content and CVF was significantly higher(P<0.01),and matrix metalloproteinase- 2 and collagen Ⅰ protein expression was significantly increased(P<0.01).Phentolamine significantly improved cardiac hypertrophy in treatment group rats,reduced hydroxy-proline,CVF,matrix metalloproteinase 2and collagen Ⅰ protein expression(P<0.05).Conclusions:Phentolamine can effectively reduce the incidence of myocardial hypertrophy and myocardial extracellular matrix remodeling in SD rats,and it can ease myocardial extracellular matrix of cardiac remodeling.It may he associated with reduced expression of matrix metalloproteinase 2 and collagen Ⅰ in myocardial tissue remodeling.

Cryoballoon pulmonary vein isolation and left atrial appendage occlusion prior to atrial septal defect closure: A case report

BACKGROUND In patients who suffer from both atrial fibrillation(AF)and atrial septal defect(ASD),cryoballoon pulmonary vein isolation(PVI),sequential left atrial appendage(LAA)occlusion and ASD closure could be a strategy for effective prevention of stroke and right heart failure.CASE SUMMARY A 65-year-old man was admitted to our institution due to recurrent episodes of palpitations and shortness of breath for 2 years,which had been worsening over the last 48 h.He had a history of AF,ASD,coronary heart disease with stent implantation and diabetes.Physical and laboratory examinations showed no abnormalities.The score of CHA2DS2VASc was 3,and HAS-BLED was 1.Echocardiography revealed a 25-mm secundum ASD.Pulmonary vein(PV)and LAA anatomy were assessed by cardiac computed tomography.PV mapping with 10-pole Lasso catheter was performed following ablation of all four PVs with complete PVI.Following the cryoballoon PVI,the patient underwent LAA occlusion under transesophageal echocardiographic monitoring.Lastly,a 34-mm JIYI ASD occlude device was implanted.A follow-up transesophageal echocardiography at 3 mo showed proper position of both devices and neither thrombi nor leakage was found.CONCLUSION Sequential cryoballoon PVI and LAA occlusion prior to ASD closure can be performed safely in AF patients with ASD.