Angina exercise-induced

Exertional angina calcium antagonists are useful in the treatment of exercise-induced angina, through their ability to increase coronary dilatation and blood flow. 

For the prevention of exercise-induced angina or in other precipitating conditions one or two 400-micrograms metered doses should be sprayed under the tongue immediately prior to the event. 

C. Clinical Use Beta-blockers are used only for prophylactic therapy of angina they are of no value in an acute attack. They are effective in preventing exercise-induced angina but are ineffective against the vasospastic form. The combination of beta-blockers with nitrates is useful... 

Propranolol. Propranolol (Table 1), a Class II antiarrhythmic agent, is usefiil in the management of hypertrophic subaortic stenosis, especially for the treatment of exertional or other stress-induced angina by improving blood flow. The dmg can increase exercise tolerance in patients suffering from angina. Propranolol has been shown to have cardioprotective action in post-MI patients (37—39,98,99,108). 

Q82 Exercise is contraindicated in controlled angina. Sv/imming is greatly associated with exercise-induced asthma. 

Exercise in not contraindicated in controlled angina. However, patients are advised to carry with them glyceryl trinitrate. Swimming is not associated with triggering of exercise-induced asthma. 

The effects of amlodipine and isosorbide-5-mono-nitrate for 3 weeks on exercise-induced myocardial stunning have been compared in a randomized, double-blind, crossover study in 24 patients with chronic stable angina and normal left ventricular function (4). Amlodipine attenuated stunning, evaluated by echocardiography, significantly more than isosorbide, without difference in anti-ischemic action or hemodynamics. Amlodipine was better tolerated than isosorbide, mainly because of a lower incidence of headache (4). 

Syndrome X refers to the occurrence of effort angina and exercise-induced ECG changes with a normal coronary arteriogram and no evidence of structural (stenosis) or functional (spasm) abnormalities. Although the basis for this syndrome is not yet established, it is thought that syndrome X may be a result of inducible myocardial ischemia caused by impaired functional coronary reserve at the mi-crovascular level of intramural prearteriolar vessels. It has been proposed that this defect is caused by defective prearteriolar regulation of blood flow into the arteriolar bed with subsequent focal, sustained, compensatory release of adenosine excessive local concentrations of adenosine are then responsible for the pain seen in this syndrome. Cardiomyopathy and left bundle block may result from ischemia in some patients. Follow-up studies have shown that the occurrence of left bundle branch block in response to stress is associated... 

Describe the benefits of verapamil therapy in exercise-induced ( stable ) angina. 

For the treatment of hypertension and angina, the initial oral dose generally is 40-80 mg/day, titrated upward until the desired response is obtained, typically at <320 mg/day. In hypertension, the full antihypertensive effect may not develop for several weeks. If propranolol is taken twice daily for hypertension, blood pressure should be measured just prior to a dose to ensure that the duration of effect is sufficiently prolonged. Adequacy of adrenergic blockade can be assessed by measuring suppression of exercise-induced tachycardia. 

EXERTIONAL ANGINA Ca + channel antagonists also are effective in the treatment of exertional angina. Their utility may result from an increase in blood flow owing to coronary arterial dilation, from a decrease in myocardial demand (secondary to a decrease in arterial blood pressure, heart rate, or contractility), or both. These drugs decrease the number of anginal attacks and attenuate exercise-induced ST-segment depression. 

Increase heart rate or reduce CBF, apparently because there is little effect on venous return to the heart. Although perhexllene diminishes exercise-induced tachycardia, It has no effect on resting heart rate, and does not appear to block g-receptors 71 on the contrary It Is reported to have bronchodllator properties In man. Early clinical trials suggest that it may prove to be useful in angina.70,73... 

Dlltlazem (Cardizem) Less pronounced heart rate reduction. Reduces afterload by dilating peripheral arteries. Increases oxygen supply to myocardium by preventing sympathetic -induced coronaiy artery spasm. Reduces angina episodes. Increases exercise tolerance in stable angina. Also used as an antihypertensive. Edema, headache, dizziness, asthenia, nausea, rash. 

For certain types of trial measurement is by titration. For example, in angina a patient may be asked to perform an exercise until a given degree of pain is experienced. In asthma it may be established at what dose of a metacholine challenge a 20% drop in FEVi is induced. There are many other examples of such measures. 

Mogensen, K., Knudsen, J.B., Rasmussen, V., Kjoiler, E. and Gormsen, J. (1985). Effect of specific thromboxane synthetase inhibition on thromboxane and prostaglandin synthesis in stable angina induced by exercise test. Thrombosis Res., 37, 259-266... 

Nifedipine (Procardia and Adalat) belongs to a class of drugs called calcium channel blockers and is effective in the treatment of various types of angina, including that induced by exercise. Show how nifedipine can be synthesized from 2-nitrobenzaldehyde, methyl acetoacetate, and ammonia. Hint Review the chemistry of your answers to Problems 19.43 and 19.54 and then combine that chemistry to solve this problem.)... 

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