Richard A. DeWall

Responses of the ischemic myocardium to allopurinol

Abstract Allopurinol was found to have a profound effect on hemodynamic, ECG, and biochemical changes of experimental myocardial ischemia produced by coronary artery ligation in dogs and sheep. Following acute infarction, intravenously administered Allopurinol caused an increase of myocardial contractility and cardiac output, reversed or prevented electrocardiographic S-T changes of ischemic origin, and exhibited prolonged antiarrhythmic effects. It is suggested that prevention of the irreversible loss of purine base from the cell during hypoxic states is the biochemical action of this drug that results in rapid recovery of the stressed myocardium. The results of the experiments indicated that Allopurinol may be a useful agent for the treatment of coronary insufficiency.

Ventricular Fibrillation Without Left Ventricular Venting: Observations in Humans

Pressures were measured in the heart and great vessels of 52 patients who underwent coronary revascularization. In 25 patients the left ventricle was vented during fibrillation; in the others a vent was not used. Samples for blood gas analysis were obtained twice during fibrillation from the aorta, left atrium, pulmonary artery, and right atrium. Left ventricular venting was found to be effective in keeping mean left heart pressure below 10 mm Hg, although temporary incompetence of the aortic valve or malfunction of the vent occasionally caused higher pressures. Vent use led to air embolism in the aorta in 16% of the patients. In the nonvented patients mean left heart pressures remained between 10 and 20 mm Hg. However, higher values were frequently observed. Blood gas analysis demonstrated that without venting, retrograde pulmonary flow occurred during fibrillation. No abnormality was encountered that could be related to nonventing.

Five-year clinical experience with the Omniscience cardiac valve.

Clinical data on the Omniscience cardiac valve prosthesis (sizes 19 to 31 mm) were obtained from 326 patients (155, aortic valve replacement [AVR]; 125, mitral valve replacement [MVR]; and 46, double-valve replacement) during a five-year period (650 patient-years) with 96% accountability. Mean age was 56 +/- 12 years, and 40% (130) of the patients were 61 years old or older. Thirty-one percent (101) had prior or concomitant coronary artery bypass grafting procedures, 9% (28) had a previous malfunctioning prosthesis, and 17% (57) had other cardiac surgical procedures. Eighty percent were in New York Heart Association (NYHA) Functional Class III or IV preoperatively. Early mortality was 10% (34). Five-year actuarial thrombus-free rate is 96% for patients who underwent AVR and 95% for patients having MVR. Postoperatively, 89% (172/193) were in NYHA Class I or II, and 84% (163/193) improved by at least one Functional Class. A significantly high proportion of the postoperative hematological values fall within normal ranges: red blood cell count, 94% (176/187); hematocrit, 88% (166/188); and hemoglobin, 93% (176/190). Ninety-eight percent (287/292) are free from clinical anemia. Four of the 5 patients with clinical anemia had a preoperative history of this condition. Levels of lactic dehydrogenase in 3 patients suggested the probable presence of clinically significant hemolysis, although all 3 have normal hematological values. Actuarial five-year survival for patients who underwent AVR or MVR are similar (82% and 80%, respectively), indicating satisfactory and comparable levels of safety and performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Experience with the Lillehei-Kaster Valve Prosthesis

The Lillehei-Kaster valve was used in 215 patients over a 7-year period. The aortic valve was replaced in 81 of them. Hospital mortality was 21% (17 patients). Ten patients were lost to follow-up and long-term mortality was 5% (3 patients). The incidence of thromboembolism was 2.6 per 100 patient-years, and actuarial survival was 96% at 5 and 87% at 7 years. Mitral valve replacement was performed in 108 patients. Hospital mortality was 20% (22 patients), 24 patients were lost to follow-up, and long-term mortality was 13% (11 patients). The combined incidence of thromboembolism was 5.0 per 100 patient-years, and actuarial survival was 81% at 5 years and 75% at 7 years. In both groups, the majority of patients improved clinically. Fifteen patients had double-valve replacement, and 11 had coronary revascularization in addition to valve replacement.

Use of Sodium Allopurinol in Treatment of Digitalis Intoxication

mals the toxic effects are usually gastrointestinal when oral administration is used, and both cardiac and gastrointestinal when rapid parenteral infusion is utilized. Experimentally induced alkalosis has been found to increase the period of toxicity in animals probably due to the resultant hypokalemia.3 Acute digitalis administration is known to produce an elevation in serum potassium which is thought to be due to the blockade of potassium reentry into the cell.4 Previous studies with allopurinol in experimental myocardial infarction,5 in which increased levels of potassium in coronary sinus blood associated with dysrhythmias were noted during ischemia, combined with the subsequent stabilizing effect of this agent, led us to pursue the potential efficacy of this compound in digitalis toxicity.

Red Blood Cell Potassium as an Index of Total Body Potassium

* From the Cox Heart Institute, Kettering Medical Center, Kettering, Ohio. Supported by grants from the Miami Valley Heart Chapter of the American Heart Association and the Kettering Foundation. The safety of open-heart surgery is strongly dependent on the adequacy of preparation of the patient for this type of surgery. One of the most important aspects is the availability of potassium for cellular needs. Because the determination of actual total body potassium is difficult, the red blood cell was ~ chosen for investigation as it is readily available and may give some indication of the relative body intracellular potassium. It was the purpose of these experiments to determine the relationship of red blood cell potassium to the