Arterial spasm

Verapamil. Verapamil hydrochloride is a pbenyl alkyl amine and is considered the prototype of the Class I calcium channel blockers. Verapamil is also a potent inhibitor of coronary artery spasm and is useful in Prinzmetal s angina and in unstable angina at rest. Verapamil produces negative chronotropic and inotropic effects. These two actions reduce myocardial oxygen consumption and probably account for the effectiveness of verapamil in chronic stable effort angina (98,99). Moreover, verapamil is an effective antihypertensive agent. 

Thromboxane A-2 has been implicated in a number of disorders of the circulatory system including coronary artery spasms, unstable angina pectoris, traumatic and endotoxic shock, and heart attacks. It is formed normally very near its receptors and is rapidly deactivated by metabolizing enzymes so circulating levels are quite low. Furthermore, it is opposed in its actions by the prostacyclins. When these controls are defective, pathology results and drugs can be the resort in attempts to restore the normal healthy balance. For one example, furegrelate (6) is a throm-... 

With regard to epinephrines potential adverse cardiac effects, it is important to remember that in anaphylaxis, the heart is a target organ. Mast cells located between myocardial fibers, in perivascular tissue, and in the arterial intima are activated through IgE and other mechanisms to release chemical mediators of inflammation, including histamine, leukotriene C4, and prostaglandin D2. Coronary artery spasm, myocardial injury, and cardiac dysrhythmias have been documented in some patients before epinephrine has been injected for treatment of anaphylaxis, as well as in patients with anaphylaxis who have not been treated with epinephrine [11, 12]. 

Ascher, E.K. Stauffer, J-C.E. and Gaasch, W.H. Coronary artery spasm, cardiac arrest, transient electrocardiographic Q waves and stunned myocardium in cocaine-associated acute myocardial infarction. 

Altura, B.T. Quirion, R. Pert, C.B. and Altura, B.M. Phencyclidine (angel dust) analogs and "sigma" opiate benzomorphans cause cerebral arterial spasm. Proc Natl Acad Sci II.SA 80 865-869, 1983. 

Altura, B. T., and Altura, B. M. (1981) Phencyclidine, lysergic acid diethyl amide and mescaline Cerebral artery spasms and hallucinogenic activity. Science, 2 1051-1052. 

The possibility of cerebrovascular action of PCP was raised by the development of focal seizures and hemiparesis in a 6-year-old boy who had ingested what was presumed to be PCP (18). Hypertensive encephalopathy with a blood pressure of260/160 occurred in an 18-year-old woman who used PCP (43). These clinical findings are compatible with in vitro studies indicating that cerebral artery spasms can be produced by PCP as well as by LSD and mescaline (4). Whether such cerebrovascular actions are pertinent to the mental effects of these drugs is questionable. 

Diltiazem reduces transmembrane influx of calcium ions into cardiac muscle cells and vascular smooth musculature. It causes widening of coronary and peripheral vessels. It increases coronary blood flow, thus, preventing the development of coronary artery spasms. It lowers elevated blood pressure and reduces tachycardia. 

A 60-year-old man comes into the office complaining of chest pains that primarily occur in the early morning and do not appear to be associated with stress or exercise. Following coronary angiography and a positive ergonovine test you determine that this patient has angina pectoris as a result of coronary artery spasm. How would you (1) treat the patient to alleviate the acute attacks when they occur and (2) treat chronically to prevent their reoccurrence ... 

It is indicated in the treatment of mild to moderate essential hypertension and in the management of chronic stable angina and angina due to coronary artery spasm. 

Vasodilation of epicardial coronary arteries Relief of coronary artery spasm... 

Nitrates benefit patients with variant angina by relaxing the smooth muscle of the epicardial coronary arteries and relieving coronary artery spasm. 

Machiels JP, Jacques JM, de Meester A. Coronary artery spasm during anaphylaxis. Ann Emerg Med 1996 27(5) 674-5. 

A 32-year-old woman, a smoker, had an evacuation after the death of her fetus at 18 weeks. Two pessaries of gemeprost 1 mg were inserted 7.25 hours apart, and about 90 minutes later she became unconscious, apneic, and cyanotic, and had dilated pupils and no detectable blood pressure or pulse. She was given 100% oxygen, intravenous adrenaline and dobutamine, and a crystalloid infusion. Her systolic pressure rose to 100 mmHg. Coronary angiography showed left and circumflex coronary artery spasm. 

A 30-year-old woman developed uterine atony and bleeding after induced abortion because of fetal death at 17 weeks of gestation (4). Sulprostone was given intravenously at a rate of 500 micrograms/hour. When additional sulprostone was injected into the uterine cervix, the patient sustained a myocardial infarction, with ventricular fibrillation and cardiocirculatory arrest, most probably due to coronary artery spasm. She was resuscitated and recovered completely. 

Scheinert D, Strand V Muller R, et al, High-dose beta-radiation after de novo stent implantation induces coronary artery spasm, Circulation 2002 105 1420-1423. 

Yamagata Y, Koga N (1984) A case of acute renal failure with severe loin pain and patchy wedge-shaped contrast enhancement after exercise due to renal artery spasm (Japanese abstract). Nippon Jinzo Gakkai Shi (Jpn J Nephrol) 26 1682-1683... 

Diitiazem [dil TYE a zem] has cardiovascular effects that are similar to those of verapamil. It reduces the heart rate, although to a lesser extent than verapamil, and also decreases blood pressure. In addition, diitiazem can relieve coronary artery spasm and is therefore particularly useful in patients with variant angina. The incidence of adverse side effects is low. Figure 18.4 shows treatment of angina in patients with concomitant diseases. 

Coronary artery spasm may account for a variety of clinical syndromes such as variant angina, acute myocardial infarction and sudden cardiac death [94]. The mechanisms of vasospasm however are not entirely clear. Atherosclerosis and hypercholesterolemia have been implicated in the pathogenesis of vasospasm [95-97] and a local hyperactivity of the coronary artery may be involved. 

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