Initial United States experience with the Paracor HeartNet⁎⁎Paracor Medical, Inc, Sunnyvale, Calif. myocardial constraint device for heart failure

ObjectiveThis study was undertaken to review the initial results and surgical safety data for the US Food and Drug Administration safety and feasibility trial of the Paracor HeartNet (Paracor Medical, Inc, Sunnyvale, Calif.) myocardial constraint device.MethodsPatients with New York Heart Association functional class II or III heart failure underwent device implantation (n = 21) through a left minithoracotomy.ResultsThe average age was 53 years (31–72 years). There were 18 men and 3 women, and 17 patients had nonischemic etiology of heart failure. Mean heart failure duration was 8.3 years (1.4-18.8 years). Average ejection fraction was 22% (11%-33%), with an average left ventricular end-diastolic dimension of 74 mm (55-94 mm). Previous medical therapy included angiotensin-converting enzyme inhibitors, β-blockers, diuretics, digoxin, and aldosterone receptor blockers. At implantation, 17 patients had implantable electronic devices: 1 biventricular pacemaker, 11 biventricular pacemakers with cardioverter-defibrillators, and 5 implantable cardioverter-defibrillators. Patient comorbidities included hypertension in 10 cases, diabetes mellitus in 8, myocardial infarction in 1, and ventricular tachycardia in 8. Mean operative time was 68 minutes (42–102 minutes), and implantation time averaged 15 minutes (5–51 minutes). The average time to ambulation was 1.6 days (1–4 days). The intensive care unit stay averaged 3.3 days (1–16 days), and hospital stay averaged 6.3 days (4–16 days). Atrial fibrillation occurred in 2 patients, and there were 2 in-hospital deaths.ConclusionsThe Paracor device can be implanted in patients with heart failure and reduced left ventricular function with a high degree of success. Significant surgical complications were infrequent. The initial US experience supports the conduct of a randomized, controlled, pivotal trial

Magnesium isotope evidence that accretional vapour loss shapes planetary compositions

It has long been recognized that Earth and other differentiated planetary bodies are chemically fractionated compared to primitive, chondritic meteorites and, by inference, the primordial disk from which they formed. However, it is not known whether the notable volatile depletions of planetary bodies are a consequence of accretion1 or inherited from prior nebular fractionation2. The isotopic compositions of the main constituents of planetary bodies can contribute to this debate3, 4, 5, 6. Here we develop an analytical approach that corrects a major cause of measurement inaccuracy inherent in conventional methods, and show that all differentiated bodies have isotopically heavier magnesium compositions than chondritic meteorites. We argue that possible magnesium isotope fractionation during condensation of the solar nebula, core formation and silicate differentiation cannot explain these observations. However, isotopic fractionation between liquid and vapour, followed by vapour escape during accretionary growth of planetesimals, generates appropriate residual compositions. Our modelling implies that the isotopic compositions of magnesium, silicon and iron, and the relative abundances of the major elements of Earth and other planetary bodies, are a natural consequence of substantial (about 40 per cent by mass) vapour loss from growing planetesimals by this mechanism

Hemolysis and Pulmonary Insufficiency following Right Ventricular Assist Device Implantation

We report a case of severe hemolysis and pulmonary valve insufficiency (PI) following right ventricular support using a paracorporeal pneumatic pump (Abiomed, Danvers, MA, USA). We speculate that the high velocity jet of blood emanating from the outflow cannula caused turbulence above the pulmonary valve, leading to PI and hemolysis. Despite the growing number of implanted ventricular assist devices, we could find no report in the literature describing pulmonary valve insufficiency secondary to right ventricular assist device (RVAD) placement. Fortunately, in this case, right ventricular function recovered sufficiently after seven days of support, allowing explantation of the device and resolution of PI and hemolysis

Report of the first U.S. patient successfully supported long term with the LionHeart completely implantable left ventricular assist device system.

We report our first successful long-term survivor in the United States with the LionHeart (Arrow International, Inc., Reading, PA) completely implantable left ventricular assist device system. The patient was initially deemed a poor candidate for cardiac transplantation and had inotrope-dependent, end-stage cardiac failure. The patient was supported for 13 months with this system. During this period of support, the patient returned to independent living and derived obvious benefits toward his daily activities with the completely implanted system. The device proved to be reliable during this period of support. Through lifestyle modification, the patient was ultimately deemed an appropriate candidate for heart transplantation and ultimately received successful transplantation