Coronary spasm

Systemic anaphylaxis in man is frequently accompanied by electrocardiographic alterations ischemic ST waves, arrhythmias and atrial fibrillation [6-11]. Anaphylactic reactions after insect stings can lead to coronary spasm or acute myocardial infarction [12, 13]. Myocardial infarction can also occur as a consequence of idiopathic... 

Rosenbaum JT Coronary spasm associated with 25 urticaria report of a case mimicking anaphylaxis. 

Forman MB, Oates JA, Robertson D, Robertson RM, Roberts LJ, Virmani R Increased adventitial mast cells in a patient with coronary spasm. N Engl JMed 1985 313 1138. 

The answer is a. (Hardman, pp 762-764.) Experimentally, nitrates dilate coronary vessels. This occurs in normal subjects, resulting in an overall increase in coronary blood flow. In arteriosclerotic coronaries, the ability to dilate is lost, and the ischemic area may actually have less blood flow under the influence of nitrates. Improvement in the ischemic conditions is the result of decreased myocardial oxygen demand because of a reduction of preload and afterload. Nitrates dilate both arteries and veins and thereby reduce the work of the heart. Should systemic blood pressure fall, a reflex tachycardia will occur. In pure coronary spasm, such as Prinzmetal s angina, the effect of increased coronary blood flow is relevant, while in severe left ventricular hypertrophy with minimal obstruction, the effect on preload and afterload becomes important. 

Patients with variant or Prinzmetal angina secondary to coronary spasm are more likely to experience pain at rest and in the early morning hours. Pain is not usually brought on by exertion or emotional stress nor is it relieved by rest the electrocardiogram (ECG) pattern is that of current injury with ST-segment elevation rather than depression. 

These vasodilator effects produce hemodynamic consequences that can be put to therapeutic use. Due to a decrease in both venous return (preload) and arterial afterload, cardiac work is decreased (p. 308). As a result, the cardiac oxygen balance improves. Spasmodic constriction of larger coronary vessels (coronary spasm) is prevented. 

Thus, the nitrates enable myocardial flow resistance to be reduced even in the presence of coronary sclerosis with angina pectoris. In angina due to coronary spasm, arterial dilation overcomes the vasospasm and restores myocardial perfusion to normal. O2 demand falls because of the ensuing decrease in the two variables that determine systolic wall tension (afterload) ventricular filling volume and aortic blood pressure. 

Angina pectoris Coronary sclerosis Coronary spasm... 

Dihydropyridine-CA reduction of cardiac afterload reduction of coronary spasm and coronary vasodilatation improved myocardial oxygen supply. 

Spasmolytic activity. Ethanol (95%), ethanol/glycerin, and glycerin extracts of the leaf, administered to guinea pigs at a dose of 50 mg/kg, was active vs vasopressin-induced coronary spasms as determined from electrocardiogram ". Ethanol (30%) extract of the dried leaf, administered to rabbits at a concentration of 1 mg/mL, was active on aorta vs K -induced contractions ". Decoction of the dried leaf, administered to rats, was active on aorta, IC501.12 mg/mL. The effect of the lyophilized extract on phenylephrine-induced contraction and endothelium was present. Decoction of the dried leaf, administered to rats, was active on the aorta vs phenylephrine-induced contraction, IC501.16 mg/mL. Water extract of the dried leaf, administered to rats at a dose of 3 mg/mL, was active on trachea vs acetylcholine-induced contractions ". Superoxide production inhibition. Seed oil, administered to rats at a concentration... 

Sodium and potassium are not the only ions which can participate in pumps and channels. Calcium is also pumped, channeled, exhanged,and stored. See Figure 23. Calcium concentration within the cell cytoplasm is very low. This allows the calcium to play a pivotal role in cellular activity. The cytoplasmic protein calmodulin binds and stores calcium ion. Various intracellular structures and organelles such as the mitochondria and sarcoplasmic reticulum also store calcium. Calcium is vital to such functions as the release of neurotransmitters from nerve cells. There are at least seven known modes of biochemical action for this ion, one of the most important of which involves stimulation of cardiac muscle protein (actin-myosin). Certain types of angina (heart pain) are believed to be caused by abnormal stimulation of cardiac arteries and muscle (coronary spasm) A relatively new class of drugs, known as the calcium channel blockers, has brought relief from pain and arrhythmias (irregular heart beats). 

The author commented that the myocardial ischemia experienced by both of these patients was thought to be due to prostaglandin-induced coronary spasm. It would be prudent to monitor every woman treated with gemeprost during the course of an abortion. 

A 58-year-old man with stable angina pectoris started to use latanoprost eye drops and over the next few days his angina worsened and occurred at rest. After 15 days, he had syncope during physical exercise. Angiography showed coronary spasm. 

In large series, sulprostone has had good tolerability with a very low complication rate. The most severe complication is myocardial infarction secondary to coronary spasm, with a frequency of one in 20 000, usually in smokers and women over 35 years of age with cardiovascular disease (SEDA-23, 436). 

Several experimental studies have provided support for the hypothesis that coronary spasm plays a major role in the pathophysiology of myocardial infarction during the administration of sulprostone. However, the possibility of myocardial infarction is not mentioned in the product information. 

Hiasa Y, Ishida T, Aihara T, Bando M, Nakai Y, Kataoka Y, Mori H. Acute myocardial infarction due to coronary spasm associated with L-thyroxine therapy. Clin Cardiol 1989 12(3) 161-3. 

We speculate that ischemia induces changes in the tubulo-interstitium by such factors as oxidative stress, apoptosis, an increase in intracellular Ca, complement activation, ICAM-1 expression, and inflammation, in a region controlled by the blood vessels, thereby influencing the blood vessels and prolonging vascular spasm. Coronary spasm persists for 15min, and cerebrovascular spasm in the presence of subarachnoid hemorrhage persists for a week in some patients. Therefore, renovascular spasm may persist for a long period. 

Nifedipine [nye FED i peen] functions mainly as an arteriolar vasodilator. This drug has minimal effect on cardiac conduction or heart rate. Nifedipine is administered orally and has a short half-life (about 4 hours) requiring multiple dosing. The vasodilation effect of nifedipine is useful in the treatment of variant angina caused by spontaneous coronary spasm. Nifedipine can cause flushing, headache, hypotension, and peripheral edema as side effects of its vasodilation activity. The drug may cause reflex tachycardia if peripheral vasodilation is marked resulting in a substantial decrease in blood pressure. 

Owing to their large caliber, the proximal coronary segments do not normally contribute significantly to flow resistance. However, in coronary sclerosis or spasm, pathological obstruction of flow occurs here. Whereas the more common coronary sclerosis cannot be overcome pharmacologically, the less common coronary spasm can be relieved by appropriate vasodilators (nitrates, nifedipine). 

The authors thought that marijuana may have enhanced triggered activity in the Purkinje fibers along with a reduction in coronary blood flow, perhaps through coronary spasm. 

A 6-month-old fetus who had been exposed to cocaine had a single-ventricle heart the authors suggested that coronary spasm, resulting in infarction, may have destroyed the right ventricle (268). 

The authors speculated that the mechanism of action was endothelial dysfunction, similar to that postulated for cocaine-induced coronary spasm. 

A calcium-channel blocking drug, e.g. nifedipine or diltiazem, is an alternative to a p-adrenoceptor blocker use especially if coronary spasm is suspected or if the patient has myocardial insufficiency or any bronchospastic disease. It can also be used with a p-blocker, or... 

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