Early versus late congestive heart failure after initially uncomplicated anterior wall acute myocardial infarction.

We determined the incidence and clinical, noninvasive, and angiographic variables contributing to postdischarge early (< or = 3 months) and late (> 3 months) congestive heart failure (CHF) after anterior wall acute myocardial infarction. The patient cohort consisted of 94 consecutive patients < 65 years of age who underwent predischarge exercise thallium-201 planar scintigraphy, rest radionuclide angiography, and coronary arteriography. At a mean of 49 months of follow-up, 10 of the 68 medically managed patients developed early CHF, and 10 had late CHF. The 10 patients with early CHF had significantly higher peak creatine kinase values (2,494 vs 1,032 IU/L, p = 0.01), and at discharge, a lower left ventricular (LV) ejection fraction (28 +/- 11% vs 41 +/- 11%, p < 0.02), more persistent thallium-201 defects (3.4 +/- 1.2 vs 2.1 +/- 1.2, p < 0.02), and fewer stress-induced redistribution defects (1.4 +/- 1.1 vs 0.4 +/- 1.1, p < or = 0.05) than those with late CHF. The early group had less multivessel disease (40% vs 90%, p < or = 0.03). Fifty percent (5 of 10) of patients who developed late CHF did so after a recurrent infarction compared with 10% (1 of 10) in the early CHF group (p < 0.07) and 8% in the group without CHF (p < 0.003). The 26 patients who underwent bypass surgery within 3 months had an LV ejection fraction and extent of ischemia and extent of angiographic stenoses comparable to patients with late CHF. None required hospitalization for CHF or had sustained a recurrent infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of bucindolol in congestive heart failure.

The sympathetic hyperactivity of congestive heart failure (CHF) may worsen cardiovascular function by down-regulation of myocardial beta-receptors. For this reason, beta blockade is proposed to be useful in CHF. Bucindolol is a new beta blocker that has intrinsic nonadrenergically-mediated vasodilation and may be valuable in treatment of CHF. To test this, 19 patients with CHF were randomized in a double-blind protocol to 3 months of treatment with bucindolol (n = 12) or placebo (n = 7). Significant improvement was seen in the bucindolol group using invasive and noninvasive tests; treadmill time increased from 445 to 530 seconds (p = 0.04), Minnesota Living With Heart Failure Questionnaire score improved from 61 to 40 (p = 0.0001), cardiac output increased from 4.0 to 4.7 (p = 0.02), and systemic vascular resistance decreased from 1,888 to 1,481 (p = 0.04). Also, peak exercise heart rate and pulmonary capillary wedge pressure decreased significantly with treatment. There were no changes in the placebo group. We conclude that bucindolol may be an effective treatment for CHF when administered chronically and that its nonadrenergic vasodilation may be an important feature.

Effect of nicardipine on rest and exercise hemodynamics in chronic congestive heart failure.

The hemodynamic response to vasodilation induced by the new calcium channel antagonist nicardipine was studied in 10 patients with severe, chronic congestive heart failure. Rest and exercise hemodynamics were evaluated in the baseline state and after 1 week of oral nicardipine therapy (30 mg 3 times daily). In addition, respiratory gas exchange and arteriovenous oxygen difference were measured to assess changes in oxygen utilization. The responses of the sympathetic nervous system were evaluated by measuring plasma norepinephrine concentrations at rest and during maximal exercise. At rest, nicardipine administration was associated with significant reductions in mean systemic arterial pressure, systemic vascular resistance, pulmonary artery wedge pressure and pulmonary arterial pressure, and significant increases in cardiac index and stroke volume index. These effects were maintained during exercise. In contrast to findings with other calcium channel antagonists, no negative inotropic effect of nicardipine was identified. Nicardipine administration was associated with reduction of arteriovenous oxygen difference. Nicardipine had no effect on plasma norepinephrine concentrations, suggesting absence of reflex sympathetic nervous activation. Thus, nicardipine-mediated vasodilation leads to significant improvements in both rest and exercise cardiac performance.

Phytochrome Control of Cell Wall-bound Hydroxyproline Content in Etiolated Pea Epicotyls.

The red light inhibition of growth of the intact pea (Pisum sativum L. cv. Alaska) third internode was correlated with an increase in the content of cell wall-bound hydroxyproline. These changes were detected 3 hours after irradiation, and possibly at 1 hour. Far red light reversed the effects of red light. The iron chelator alpha,alpha'-dipyridyl reversed the red light effects on both growth and hydroxyproline content. Using segments incubated in vitro, no phytochrome-mediated change in hydroxyproline content could be observed, perhaps because of an overwhelming wounding response. If plants were irradiated in situ and grown for 8 hours before excision and incubation of segments, some enhancement of hydroxylation by red light was detectable both colorimetrically and radioisotopically. The red light inhibition of segment growth was reversed by alpha,alpha'-dipyridyl. These results are examined in reference to the role of extensin in normal and induced growth cessation.