Cardiovascular system cardiac ischemia

Ca2+ is an important intracellular second messenger that controls cellular functions including muscle contraction in smooth and cardiac muscle. Ca2+ channel blockers inhibit depolarization-induced Ca2+ entry into muscle cells in the cardiovascular system causing a decrease in blood pressure, decreased cardiac contractility, and antiarrhythmic effects. Therefore, these drugs are used clinically to treat hypertension, myocardial ischemia, and cardiac arrhythmias. 

As for the cardiovascular system, the cardioprotective effects of selective H3-receptor agonists, demonstrated in models of protracted myocardial ischemia (Imamura et al., 1994, 1995, 1996a Hatta et al., 1996, 1997), could be predictive of beneficial effects in coronaropatic patients. Hence, the attenuation of carrier-mediated noradrenaline release in hypoxic and/or ischemic myocardium by H3-agonists would limit the sympathetic overactivity and the associated incidence of ventricular arrhythmias and angina, as well as the increase of metabolic demand by the myocardium, thus preventing further damage and cardiac failure. 

Adverse cardiovascular effects seen with intravenously infused pressor agents include marked elevations in blood pressure that cause increased cardiac work, which may precipitate cardiac ischemia and failure. Systemically administered Preceptor-stimulant drugs may cause sinus... 

Cocaine also blocks the reuptake of norepinephrine in the PNS the combination of central and peripheral actions leads to a high probability of toxicity. The cardiovascular system is particularly sensitive to the actions of cocaine, and cardiac arrhythmias, marked increases in blood pressure, cerebral hemorrhage, myocardial ischemia, and outright heart failure are not uncommon with cocaine use. Even young, otherwise healthy individuals with normal coronary and cerebral arteries have died suddenly after cocaine use from cerebral hemorrhage or ventricular fibrillation. There have been several deaths of famous athletes attributed to cocaine cardiotoxicity. These cardiotoxic effects may be related to increased intracellular calcium levels and involve both cardiac and vascular actions of the drug. 

Cocaine can have marked effects on the heart and cardiovascular system. Adverse actions may include myocardial ischemia, cardiac arrhythmias, cardiotoxicity, hypertensive effects, cerebrovascular events, and a hyperco-agulable state (24,40). By 1997 more than 250 cases of myocardial infarction related to the recreational use of cocaine had been documented in the literature (41). Although less common, aortic dissection related to use of cocaine-free base ("crackcocaine") has also been documented (42). Seizures also can be associated with cocaine use (43). 

Cardiovascular System The hypotensive effect of sevoflurane primarily is due to systemic vasodilation, although sevoflurane also produces a concentration-dependent decrease in cardiac output. Unlike isoflurane or desflurane, sevoflurane does not produce tachycardia and thus may be a preferable agent in patients prone to myocardial ischemia. 

The main effect of hawthorn is on the cardiovascular system. Pharmacological studies report enhanced coronary blood flow and myocardial perfusion improvement of cardiac muscle contractility increased left ventrical output velocity lowering of blood pressure " an antiarrhythmic effect increased myocardium tolerance to oxygen deprivation under hypoxic conditions cardioprotective effect against myocardial infarc-tion and stimulation of revascularization after myocardial ischemia (escop 1) Various clinical studies reveal efficacy in congestive heart failure increased cardiac performance decrease in peripheral vascular... 

No therapy for advanced/decompensated heartfailure studied to date has been shown conclusively to influence mortality. Treatment goals are directed toward restoration of systemic oxygen transport and tissue perfusion, relief of pulmonary edema, and limitation of further cardiac damage. Maximizing oral therapy and using combinations of shortacting intravenous medications with different cardiovascular actions often are needed to optimize cardiac output, relieve pulmonary edema, and limit myocardial ischemia. Invasive hemodynamic monitoring usually is required to provide immediate feedback on treatment efficacy and adverse effects. 

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