Beta blockade during and after myocardial infarction: an overview of the randomized trials

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(97)11096-0.pdf

Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children

The innervation of the cranial vessels by the trigeminal nerve, the trigeminovascular system, has recently been the subject of study in view of its possible role in the mediation of some aspects of migraine. Since stimulation of the trigeminal ganglion in humans leads to facial pain and flushing and associated release of powerful neuropeptide vasodilator substances, their local release into the extracerebral circulation of humans was determined in patients who had either common or classic migraine. Venous blood was sampled from both the external jugular and the cubital fossa ipsilateral to the side of headache. Plasma levels of neuropeptide Y, vasoactive intestinal polypeptide, substance P, and calcitonin gene-related peptide were determined using sensitive radioimmunoassays for each peptide, and values for the cubital fossa and external jugular and a control population were compared. A substantial elevation of the calcitonin gene-related peptide level in the external jugular but not the cubital fossa blood was seen in both classic and common migraine. The increase seen in classic migraine was greater than that seen with common migraine. The other peptides measured were unaltered. This finding may have importance in the pathophysiology of migraine.

Vasoactive peptide release in the extracerebral circulation of humans during migraine headache

Nervous connections between the trigeminal ganglia and cerebral blood vessels have recently been identified in experimental animals and have been termed the trigeminovascular system. Existence of this system in humans is inferential. Trigeminovascular neurons and their peripheral unmyelinated nerve fibers contain the neurotransmitter peptide substance P. Most newly synthesized substance P is transported from ganglion cell bodies to afferent nerve fibers, where depolarization-induced release of neurotransmitter into the wall of the cerebral blood vessel occurs. Substance P dilates pial arteries, increases vascular permeability, and activates cells that participate in the inflammatory response. The relationship of trigeminovascular fibers to the pathogenesis of vascular head pain sheds light on possible mechanisms of migraine and other central nervous system conditions associated with headache and inflammation.

The neurobiology of vascular head pain.

In a double-blind trial of streptokinase for acute myocardial infarction, 219 consecutive patients presenting with infarction within four hours (mean, 3.0 +/- 0.8) of the onset of chest pain were randomly assigned to treatment with streptokinase (1.5 million units) or placebo, given intravenously over 30 minutes. The primary end point of the study was left ventricular function in patients with first infarctions. Patients who could undergo beta-blockade also received intravenous propranolol. Heparin (for 48 hours) and a combination of low-dose aspirin and dipyridamole were administered to both groups until cineangiography was performed at three weeks. In the patients with first infarctions treated with streptokinase, the left ventricular ejection fraction was 6 percentage points higher (streptokinase vs. placebo, 59 +/- 10.5 vs. 53 +/- 13.5 percent; P less than 0.005), with benefit to patients with either anterior infarction (57 +/- 11.9 vs. 49 +/- 15.9 percent; P less than 0.05) or inferior infarction (60 +/- 9.1 vs. 55 +/- 11.3 percent; P less than 0.05). Left ventricular function was improved regardless of whether concomitant propranolol was given. Survival (at 30 days) was improved with streptokinase: 2 deaths occurred among 79 patients who received this drug, as compared with 12 deaths among 93 patients who received placebo (2.5 vs. 12.9 percent, P = 0.012). Rates of reinfarction (streptokinase vs. placebo, 3 vs. 1 percent) and requirements for surgery or angioplasty (7 vs. 5 percent) were similar in the two groups. We conclude that administration of intravenous streptokinase (1.5 million units) to patients with a first myocardial infarction results in improved left ventricular function and short-term survival.

Judith Andrews

Papers

Alpha-1-antitrypsin, autism, and cœliac disease