Search

The Apico Aortic Blood Pump (AABP) is a centrifugal continuous flow left ventricular assist device (LVAD) with ceramic bearings. The device is in the initial development phase and is being designed to be attached directly to the left ventricular apex by introducing an inlet cannula. This paper reports results from in vitro experiments. In order to evaluate implantation procedures and device dimensioning, in vitro experiments included an anatomic positioning study for the analysis of surgical implantation procedure and device dimensions and positioning that was performed using the body of a pig. The results revealed no damage caused by the device, and the surgical implantation procedure was considered feasible. Hydrodynamic performance curves were obtained to verify the applicability of the device as an LVAD, showing adequate performance. Mechanical blood trauma was analyzed through 6-h hemolysis tests, with total pressure head of 100 mm Hg and flow of 5 L/min. Mean normalized index of hemolysis was 0.009 g/100 L (±0.002 g/100 L). Studies using a hybrid cardiovascular simulator were conducted for three types of circulatory conditions: normal healthy conditions, concentric hypertrophic heart failure (CHHF), and CHHF with AABP assistance. Analysis of cardiovascular parameters under those three conditions demonstrated that when the AABP was assisting the system, parameters under CHHF conditions went back to normal healthy values, indicating the AABP's effectiveness as CHHF therapy. Our preliminary results indicate that it is feasible to use the AABP as a LVAD. The next steps include long-term in vivo experiments.

A 23-year-old-female patient had undergone a very successful gastric banding surgery to treat obesity. Six months later she began to present recurrent syncope due to very frequent, intermittent high-degree AV block referred to as pacemaker implantation. The electrophysiological study showed impaired AV nodal conduction but the His-Purkinje conduction was preserved. Partial catheter radiofrequency ablation of the cardiac autonomic nervous system guided by spectral endocardial mapping (cardioneuroablation) was performed. The electrophysiological parameters were normalized. Holter recordings were normal and the patient was asymptomatic with normal life without pacemaker implantation in a follow-up 21 months later.

PACHON, J.C., et al.: Ventricular Endocardial Right Bifocal Stimulation in the Treatment of the Severe Dilated Cardiomyopathy Heart Failure with Wide QRS. The QRS widening by ventricular conventional pacing impairs the systolic and diastolic functions and increases mitral regurgitation. The aim of this study was to compare conventional pacing to an alternative stimulation mode with a narrower QRS using two leads in the RV. Thirty-nine (25 men, 14 women; mean age 60.1 ± 15.1 years) dilated cardiomyopathy patients (Chagas' disease [n = 17], coronariopathy [n = 9], AV ablation for tachycardiomyopathy [n = 3], and other [n = 10]) with cardiac failure (NYHA 3.1 ± 0.8), pacemaker indication, and chronic AV block (22 AF) had endocardial pacemaker implantations (27 Biotronik, 12 Guidant). Two RV leads (one septal, one conventional [RV apex] were connected, respectively, to the atrial and ventricular pacemaker plugs. After clinical stabilization they were studied under three stimulation modes in the same session: AAI (septal), VVI (conventional), and ventricular endocardial right bifocal stimulation (VERBS) (DDT/DVI/DDD = AV interval = 15/10 ms). In comparison to conventional pacing, VERBS increased ejection fraction (0.124), cardiac output (19.5%), and peak filling rate (31.0%), and decreased QRS duration (24.7%), left atrium area (11.9%), mitral regurgitation area (32.3%), the diastolic transmitral flow (E/A relation) (19.3%), and the propagation flow time (18.0%) from the mitral valve to the left ventricular apex (tE_col), (P < 0.05). The quality-of-life showed an impressive score reduction of 50.4%. The septal stimulation alone showed a less expressive benefit. In severe dilated cardiomyopathy with classic pacemaker indication, VERBS showed significantly better performance than the septal or the conventional stimulation alone. There was a good systolic and a remarkable diastolic improvement causing an important reduction in the quality-of-life score.

Three hundred episodes of infective endocarditis (IE) in 287 patients were studied from October 1978 to August 1986. The patients were in the age range of 0.2-78 (mean 30.76 +/- 16.06) years; 185 (68%) occurred in male patients. The etiologic agents were: Streptococci viridans group (93), enterococci (21), streptococci D group, nonenterococci (19), other streptococci (14), Staphylococcus aureus (59), Staphylococcus epidermidis (14), gram-negative bacteria (16), other gram-positive bacteria (16), fungi (4). Etiologic agents were not isolated in 52 (negative cultures). Valvular heart diseases occurred in 231 episodes, congenital heart diseases in 37, other heart diseases in 6. Sixty-nine occurred in patients with prosthetic heart valves. In 69 there was no previous heart disease. Surgical treatment was performed in 102 episodes (37 with prosthetic valve IE and 65 with native valve IE); 22 patients (21%) died, 12 with prosthetic valve and 10 with native valve IE. The in-hospital mortality (medical and surgical patients) was 26% (78 patients). Long-term follow-up of 206 patients up to 7.1 (mean 2.13 +/- 1.68) years revealed that 26 patients died. Thus, IE remains a disease with high mortality and is fatal to a third of the patients, in spite of the progress in therapeutic methods. Its morbidity and mortality continues beyond the microbiological cure.

Background Aneurysms and dissections involving the descending thoracic aorta and the distal portion of the aortic arch are difficult to resolve surgically. The introduction of endovascular self-expanding stent-grafts has simplified the operation. Given the complications associated with their peripheral placement, we explored the feasibility of surgical insertion. Methods Thirteen patients underwent surgical insertion of a stent-graft into the aortic arch via longitudinal aortotomy. Six patients had aneurysms (ruptured in two, and seven dissections (acute in two, ruptured in one). Five patients also underwent associated procedures including aortic valve replacement (one), ascending aorta replacement (two), arch replacement (one), and coronary artery bypass (one). Results There was one intraoperative death due to ascending aortic dissection, and two hospital deaths due to multiple complications. Of ten patients discharged, one died 3 months postoperatively. The remaining survivors are well, and imaging studies confirmed adequate correction of the aortic disease. Conclusions The use of this technique simplifies the operation and treatment of particular cases of aortic disease. The observed morbidity and mortality are due to factors independent of the technique.

Hemodynamic deterioration occurs with ventricular pacing rate increase in the presence of severe chagasic cardiomyopathy. Syncope and orthopnea occurred during ventricular pacemaker evaluation when the pacing rate was temporarily increased by magnet application. Cardiac output decreased by 54%, the arterial blood pressure by 38%, and the pulmonary wedge pressure increased by 54%. Such severe myocardial compromise may limit the use of rate modulated pacemakers.