Of wholes and parts: A Thomistic refutation of "Brain Death".

I propose a refutation of the two major arguments that support the concept of "brain death" as an ontological equivalent to death of the human organism. I begin with a critique of the notion that a body part, such as the brain, could act as "integrator" of a whole body. I then proceed with a rebuttal of the argument that destruction of a body part essential for rational operations-such as the brain-necessarily entails that the remaining whole is indisposed to accrue a rational soul. Next, I point to the equivocal use of the terms "alive" or "living" as being at the root of conceptual errors about brain death. I appeal to the Thomistic definition of life and to the hylomorphic concept of "virtual presence" to clarify this confusion. Finally, I show how the Thomistic definition of life supports the traditional criterion for the determination of death. Lay summary: By the mid-1960s, medical technology became available that could keep "alive" the bodies of patients who had sustained complete and irreversible brain injury. The concept of "brain death" emerged to describe such states. Physicians, philosophers, and ethicists then proposed that the state of brain death is equivalent to the state of death traditionally identified by the absence of spontaneous pulse and respiration. This article challenges the major philosophical arguments that have been advanced to draw this equivalence.

Heterologous embryo transfer: Magisterial answers and metaphysical questions.

The debate regarding the morality of heterologous embryo transfer (HET) as a solution for the fate of cryopreserved embryos remains active. This paper endeavors to show that the magisterial instructions on bioethical issues can only lead to the conclusion that HET is always morally illicit. I begin by showing that the text of Dignitas personae recognizes HET as a procedure accomplishing a procreative function, and I indicate that it is through gestation that this procreative function occurs. I further show that the previous Instruction, Donum vitae, implicitly points to an ontological or spiritual consideration at play during gestation. This consideration is likely related to the procreative function identified in Dignitas personae. Finally, I place these two textual arguments in the context of the debate concerning HET and conclude that metaphysical questions must be clarified in order for the immorality of HET to be understood from a suitable anthropological perspective and gain more widespread acceptance.

Left ventricular systolic unloading and augmentation of intracoronary pressure and Doppler flow during enhanced external counterpulsation.

BACKGROUND: Enhanced external counterpulsation (EECP) is a noninvasive, pneumatic technique that provides beneficial effects for patients with chronic, symptomatic angina pectoris. However, the physiological effects of EECP have not been studied directly. We examined intracoronary and left ventricular hemodynamics in the cardiac catheterization laboratory during EECP. METHODS AND RESULTS: Ten patients referred for diagnostic evaluation underwent left heart catheterization and coronary angiography from the radial artery. At baseline and then during EECP, central aortic pressure, intracoronary pressure, and intracoronary Doppler flow velocity were measured using a coronary catheter, a sensor-tipped high-fidelity pressure guidewire, and a Doppler flow guidewire, respectively. Similar to changes in aortic pressure, EECP resulted in a dramatic increase in diastolic (71+/-10 mm Hg at baseline to 137+/-21 mm Hg during EECP; +93%; P<0.0001) and mean intracoronary pressures (88+/-9 to 102+/-16 mm Hg; +16%; P=0.006) with a decrease in systolic pressure (116+/-20 to 99+/-26 mm Hg; -15%; P=0.002). The intracoronary Doppler measure of average peak velocity increased from 11+/-5 cm/s at baseline to 23+/-5 cm/s during EECP (+109%; P=0.001). The TIMI frame count, a quantitative angiographic measure of coronary flow, showed a 28% increase in coronary flow during EECP compared with baseline (P=0.001). CONCLUSIONS: EECP unequivocally and significantly increases diastolic and mean pressures and reduces systolic pressure in the central aorta and the coronary artery. Coronary artery flow, determined by both Doppler and angiographic techniques, is increased during EECP. The combined effects of systolic unloading and increased coronary perfusion pressure provide evidence that EECP may serve as a potential mechanical assist device.

Management After Myocardial Infarction.

Individuals who survive an acute myocardial infarction (MI) have up to a ninefold greater risk of cardiovascular morbidity and mortality compared with the general population. The modification of traditional coronary risk factors, including hypertension, hyperlipidemia, tobacco use, and diabetes mellitus, constitutes one of the cornerstones of management after acute MI. Therapies aimed at reversing the pathophysiologic disorders that lead to endothelial dysfunction, thrombosis, and atherosclerotic plaque instability may improve the prognosis for patients after acute MI. Aggressive risk stratification diagnostic testing can identify patients at the highest risk for adverse events. Prior to hospital discharge, patients should have an evaluation of left ventricular systolic function, an assessment for the risk for residual myocardial ischemia, and a clinical assessment of the risk for serious ventricular arrhythmias. An array of pharmaceutical agents is available for the secondary prevention of MI, including antiplatelet agents, beta-blockers, angiotensin-converting enzyme inhibitors, and statins.