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D G Lucas

Publications and source records attributed to D G Lucas.

3 recordsLinked to original sources
PubMed2001

Effects of adenosine receptor subtype A1 on ventricular and renal function.

The adenosine subtype 1 (A1) receptor, which may influence cardiac function and modulate renal function, may have particular relevance in congestive heart failure (CHF). However, the effects of A1 receptor inhibition in the setting of CHF are poorly defined. Systemic hemodynamics and indices of renal function were measured in pigs with pacing-induced CHF at 240 bpm for 3 weeks (n = 10) before and after A1 receptor blockade with 100 microg of BG9719 (1,3-dipropyl-8-[2-(5,6-epoxynorbornyl)]xanthene) or in CHF pigs after infusion of vehicle only (n = 10). Heart rate, mean aortic pressure, and left ventricular peak pressure increased following A1 blockade in the CHF group, consistent with an adenosine inhibitory effect. However, cardiac output and global measures of vascular resistance did not significantly change following A1 blockade. Urine output increased twofold and sodium clearance increased threefold following A1 blockade (p < 0.05). Creatinine clearance increased following A1 blockade (127 +/- 17 vs. 62 +/- 7 ml/min, p < 0.05). Selective A1 receptor blockade improved glomerular filtration rate and induced a natriuresis and diuresis in a model of CHF without adverse effects on cardiac function. These unique results suggest that renal A1 receptor activation may contribute to the reduced renal function associated with CHF.

Animals↗
PubMed2000

Surgical options for the treatment of heart failure.

This article will examine the role of specific surgical interventions for congestive heart failure (CHF). The most definitive surgical option for severe end-stage heart failure is cardiac transplantation. In general, patients considered for heart transplant should have severe heart disease despite all other therapies with a high risk of death within 1 year. Noncardiac conditions that would by themselves shorten life expectancy or increase the risks of rejection, infection, or other fatal complication, should not be present. However, in light of the limited donor pool, complications associated with long-term immunosuppressive therapy, and the ever-increasing number of CHF patients, the role of cardiac transplantation for CHF will continue to be limited. The conduct of and evaluation for cardiac transplantation has been well described previously and therefore will not be evaluated in this review (1); however, there has been recent progress in the genetic modification of animal organs for potential use in transplantation (xenografts) (2). If these developments come to fruition, then cardiac transplantation/organ replacement may become a surgical option for a much greater number of CHF patients. One alternative approach to complete cardiac transplantation is the surgical placement of transformed cells into the diseased myocardium, briefly discussed under "Future Directions." This article will examine surgical options that are currently being used for CHF patients, surgical modalities that are currently under clinical evaluation, and finally, potential future therapies with respect to surgical options for heart failure.

Algorithms↗