Verapamil in stable effort angina: Effects on left ventricular function evaluated with exercise radionuclide ventriculography

A double blind placebo-controlled study was performed in 12 patients with stable angina pectoris to evaluate the effects of oral verapamil (320 mg/day) on left ventricular function, as measured at rest and during exercise with gated equilibrium radionuclide ventriculography. On verapamil, patients had a lower heart rate-blood pressure product at each work load than with placebo. Anginal threshold increased by 28 ± 19 watts (p < 3.005), and maximal exercise capacity increased by 20 ± 14 watts (p < 0.001) with verapamil, but the rate-pressure product at the onset of angina and at maximal exercise was unchanged. Left ventricular ejection fraction at rest during verapamil therapy was the same as with placebo therapy. On exercise during placebo therapy, the ejection fraction decreased from 40 ± 9 to 35 ± 11 percent (p < 0.025) because end-systolic volume increased disproportionately compared with end-diastolic volume. On exercise during verapamil therapy, the ejection fraction did not decrease (44 ± 8 versus 45 ± 12 percent) and was significantly higher at identical work loads than on placebo because of a smaller increase in end-systolic volume. Oral verapamil is effective treatment for effort angina and may prevent the decrease in left ventricular ejection fraction due to exercise-induced ischemia.     

The QRS scoring system for estimating myocardial infarct size: clinical, angiographic and prognostic correlations

The relation between a QRS score derived from the routine electrocardiogram and left ventricular function was investigated in 181 patients after myocardial infarction. Patients with left ventricular hypertrophy and conduction defects were excluded. The QRS score correlated closely with the severity of wall motion abnormalities and left ventricular ejection fraction. The more severe the dyssynergy, the higher the QRS score (hypokinesia = 3.0; akinesia = 5.4; dyskinesia = 9.1). The left ventricular ejection fraction (percent) = 66 - (3.3 x QRS score) (correlation coefficient [r] = -0.81, probability [p] less than 0.001). With use of this regression equation, the QRS score predicted angiographic left ventricular ejection fraction to within 12% of the angiographic ejection fraction in 29 of 30 additional patients studied prospectively. The QRS score was also related to clinical functional class. The worse the clinical manifestation of left ventricular dysfunction, the higher the QRS score (Killip class I = 3.5; class II = 6.5; class III = 7.1). A QRS score greater than or equal to 7 had a specificity of 97% and a sensitivity of 59% for predicting an ejection fraction of less than 45%. Patients with a QRS score of 7 or greater had severe wall motion abnormalities, higher peak serum creatine kinase levels, higher prevalence of multivessel coronary disease, poor clinical functional class and an unfavorable outcome. The QRS score provides an inexpensive, clinically useful estimate of left ventricular function after myocardial infarction and can identify patients at high risk.     

The effect of high-dose intravenous nitroglycerin on cardiovascular hemodynamic features and left ventricular function at rest and during exercise in patients with exertional angina

Intravascular pressures, cardiac output and left ventricular function were measured at rest and during exercise in 14 patients with stable angina pectoris before and during an intravenous nitroglycerin infusion. Nitroglycerin was infused at a rate sufficient to reduce mean arterial pressure at rest by 15 to 25 mm Hg.At rest, the end-diastolic volume index decreased from 57 ± 13 to 39 ± 3 ml/m², stroke volume index from 32 ± 6 to 24 ± 5 ml/m² and mean arterial pressure from 112 ± 16 to 91 ± 14 mm Hg. The cardiac output was maintained by an increase in heart rate from 73 ± 9 to 92 ± 37 beats/min. The left ventricular ejection fraction increased from 57 ± 7 to 62 ± 9% because the stroke volume decreased less than the end-diastolic volume.All 14 patients were limited by angina in the prenitroglycerin exercise study, and the mean ST-segment depression at maximal work load was 2.2 ± 1.2 mm. At identical work loads in the nitroglycerin study, only 4 patients had angina, and the mean ST-segment depression was 0.3 ± 0.5 mm. Ten of the 14 patients improved their exercise performance by at least 30 W.Comparing the 2 exercise studies at the maximal work load achieved in the prenitroglycerin study, the mean pulmonary artery wedge pressure was decreased from 23 ± 6 to 6 ± 4 mm Hg, the end-diastolic volume index from 38 ± 15 to 27 ± 12 ml/m², and the mean arterial pressure from 132 ± 8 to 114 ±13 mm Hg. The stroke volume index and the heart rate were not significantly altered and the ejection fraction increased from 56 ± 8% to 66 ± 8%.Thus, in the high dose administered, nitroglycerin decreased left ventricular filling pressure, heart size, and stroke volume at rest and increased the ejection fraction. During exercise, nitroglycerin decreased myocardial ischemia and improved exercise tolerance. An increase in exercise ejection fraction was associated with an increase in the ratio of systolic pressure to end-systolic volume, suggesting that there was an improvement in contractile performance.     

Familial hepatic venoocclusive disease with probable immune deficiency.

Five infants from three families died between the ages of 2 and 7 months with venocclusive disease of the liver. No dietary, toxic, or other extrinsic cause was uncovered. In one family the first infant was breast-fed; the second one received no breast milk. In two of the families the parents were cousins. All infants had some evidence of immune deficiency, including hypogammaglobulinemia in at least three, multiple infections especially Pnumocystis carnii and enteroviruses, and lymphoid tissues devoid of germinal centers and mature plasma cells. Other findings in some of the infants, not previously recorded in venoocclusive disease, were microcephaly, multiple small cerebral softening, and left atrial endocardial fibrosis. A congenital cause for venoocclusive disease is suggested in these cases.     

Variability of Alternaria alternata: Biochemical and immunological characteristics of culture filtrates from seven isolates

Biochemical variability of culture filtrates from the common allergenic mold Alternaria alternata was studied. Differences between culture filtrates from 7 different isolates and between 4 batches of culture filtrate from the same isolate were observed, suggesting the unreliability of presently employed biochemical methods in the routine standardization of mold allergens and the possibility of difficulties in developing standard techniques for their purification. Dextranases, cellulases, and agarases, found in one culture filtrate, may be a further source of problems in laboratory techniques employing A. alternata. The proportions of nitrogen: carbohydrate: dialyzed dry weight were different in culture filtrates from each isolate. Polysaccharides in culture filtrates from 3 of the 7 isolates contained glucose, mannose, xylose, galactose, and a fifth, unidentified sugar. Polysaccharides from one isolate lacked xylose, and the fifth sugar was not demonstrable in 4 of the isolates. Despite the biochemical differences, extensive antigenic cross-reactivity between different isolates was found in precipitin studies and inhibition of antibody binding.