ObjectiveTo establish a mouse model of pressure overload-induced heart failure via suprasternal notch approach. MethodsMale mice were separated into a sham group and an experiment group. Through suprasternal notch approach, the aortic arch port between the origin of the right innominate and left common carotid arteries was partially clipped with tantalum clip, which had a remaining opening of 0.35 mm or 0.25 mm in diameter to cause progres-sively increased afterload. Echocardiography was performed 10 weeks after aortic arch clipped or sham surgery to deter-mine left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular posterior wall end-diastolic thickness (LVPWD), ejection fraction (EF) and fractional shortening (FS). After hemodynamic recordings were completed, mouse body weight (BW) and heart weight (HW) were measured for obtaining HW/BW ratio (mg/g). After heart function examination, mice blood sample was collected for evaluation of serum N-terminal pro-brain natriuretic peptide (NT-proBNP). At the end, part of left ventricular free wall was excised, and hematoxylin and eosin stain was made for histopathological examination. ResultsThe HW/BW, LVEDD and serum NT-proBNP significantly increased in the experiment group compared with those in the sham group (P < 0.01, respectively). The LVPWD, EF and FS significantly decreased compared with the sham group (P < 0.01, respectively). Histopathological examination showed malalignment and rupture of cardiac muscle fibers, hypertrophy and degeneration of myocardial cells, part of which had local or patchy necrosis in left ventricule postoperatively 10 weeks. ConclusionThe model of pressure overload-induced heart failure in mice established through suprasternal approach is simple, minimally invasive and reliable.
Objective To evaluate clinical results of concomitant mitral valve replacement （MVR） and modified maze procedure with Atricure bipolar radiofrequency for chronic atrial fibrillation （AF）. Methods Clinical data of 59 patients with mitral valve diseases and chronic AF who underwent concomitant MVR and bipolar radiofrequency ablation in Subei People’s Hospital from June 2010 to September 2012 were retrospectively analyzed. There were 22 male and 37 female patients with their age of 29-71 （48±11） years. The AF duration was 1.2-26.0 （7.2±3.4） years. Preoperatively，there were 20 patients with New York Heart Association （NYHA） class Ⅱ，31 patients with NYHA class Ⅲ and 8 patients with NYHA class Ⅳ. There were 32 patients with moderate to severe mitral stenosis，9 patients with moderate to severe mitral regurgitation and 18 patients with combined mitral stenosis and regurgitation. There were 42 patients with tricuspid regurgitation. The left artial dimension was 39-98 （55.2±8.9） mm. Left atrial thrombus was found in 9 patients. Atricure bipolar radiofrequency system was used for right atrial ablation under normothermic cardiopulmonary bypass （CPB） with beating heart first，then for ablations of the left and right pulmonary vein orifices and left atrium under moderate hypothermia with heart arrest. MVR was performed after ablation procedures were completed. Amiodarone was routinely used postoperatively and patients were periodically followed up after discharge. Results There was no in-hospital death. CPB time was 65-180 （99±28）minutes，aortic cross-clamping time was 46-123 （69±17）minutes，and ablation time was 15-28 （21±4）minutes. Postoperatively，heart rhythm immediately changed to sinus rhythm （SR） in 44 patients，remained AF in 10 patients and atrial flutter in 1 patient. Temporary pacemaker was used for 4 patients with bradycardia （3 patients recovered SR and 1 patient remained AF later）. Fifty-eight patients were followed up after discharge for 6-33 months，and 1 patient was lost during follow-up. Patients’ SR rate was 86.2 % （50/58），91.4% （53/58），89.7 % （52/58），84.6 % （33/39）and 71.4 % （5/7）at discharge，3 months，6 months，1 year and 2 years after discharge respectively. There was no thrombotic event during follow-up. Conclusion Concomitant MVR and modified maze procedure with Atricure bipolar radiofrequency is a safe procedure for chronic AF with good short-term results.