Nitrate vasodilators cardiac effects

Cardiac work furthermore depends strongly on the state of the circulation system physical rest or work demand appropriate cardiac performance the level of mean blood pressure is an additional decisive factor. Chronic elevation of afterload leads to myocardial insuf ciency. Therefore, all blood pressure-lowering drugs can have an important therapeutic influence on the myocardium. Vasodilator substances (e.g., nitrates) lower the venous return and/or peripheral resistance and, hence, exert a favorable effect in angina pectoris or heart failure. 

Hydralazine now has little use long-term for hypertension, but it may have a role as a vasodilator (plus nitrates) in heart failure. It reduces peripheral resistance by directly relaxing arterioles, with negligible effect on veins. In common with all potent arterial vasodilators, its hypotensive action is accompanied by a compensatory baroreceptor-mediated sjmpathetic discharge, causing tachycardia and increased cardiac output. There is also renin release with secondary salt and water retention,... 

Nicorandil is an effective vasodilator through two actions. It acts as a nitrate by activating cyclic GMP (see above) but also opens the ATP-dependent potassium channel to allow potassium efflux and h5rperpolarisation of the membrane which reduces calcium ion entry and induces muscular relaxation. It is indicated for use in angina, where it has similar efficacy to p-blockade, nitrates or calcium channel blockade. It is administered orally and is an alternative to nitrates when tolerance to these is a problem, or to the other classes when these are contraindicated by asthma or cardiac failure. Adverse effects to nicorandil are similar to those of nitrates, with headache reported in 35% of patients. It is the only antianginal drug for which at least one trial has demonstrated a beneficial influence upon outcome. ... 

---