Heart failure is the inability of the heart to pump enough blood to meet the body demand, which can be as a result of aging; the process can be stimulated by myocardial infarction, coronary artery disease, mitral, chronic hypertension and sometimes diabetes mellitus, pharmacological invention is geared to prevention and alleviating the primary cause because heart failure is as a result of secondary consequence. Therefore it is important to control lipid level, blood pressure and blood glucose.
Cardiovascular changes occur as result of the heart being unable to eject all blood from the left ventricle because of this deficit the heart respond by increasing the out put pressure which ultimately lead to increased pulse wave on the entire systemic circulation, which increases the mean arterial pressure with each subsequence heart beat, because of this after load the myocardial muscle of the left ventricle adapt by hypertrophying for the short run, however in the long run the heart is unable to compensate hence cough and shortness of breath are registered in chronic hypertension.
The pathophysiology of heart failure result from decreased myocardial contraction which lead to reduced blood pressure characterized by decreased supply in the kidney which respond by secreting rennin-Angiotensin, a system responsible for the activation of the already secreted aldosterone by the which primarily causes retention of sodium ions and water retention, increased peripheral resistance, but causes edema of the limbs, increased blood volume and after load as a secondary event.
finally leading to myocardial workload, simultaneously heart failure may occur both the right and left ventricles, it may predominantly affect the right side from increased preload resulting in pulmonary edema,on the peripheral and impaired blood supply to body organs for instance the liver, however cardiac decompensation may occur and present itself as dyspnea, fatigue, pulmonary congestions which causes cough and orthopnea and pulmonary edema where the patient feels like suffocating and sometimes extreme anxiety which may become worse at night.
Appropriate medication is aimed at alleviating the symptoms by decreasing the heart rate, myocardial workload and increased contractibility; overtime the heart may lose it responsiveness compensate for increased workload . whereby it is advisable to restrict sodium and water to such patients; however other factors such as myocardial ischemia may aggravate the situation of acute heart failure.
Treatment with ACT (Angiotensin covering enzyme) inhibits which mode of action involve lowering the peripheral resistance and prevent secretion of aldosterone, which ultimately lead to reduced arterial blood pressure hence removing the after load, and the dilation of the veins which lead to substantial reduced work load.
An example of these drugs include lisinopril which is used for several weeks or months for the condition to return to normality, dosage recommended for an adult is 10mg/day, however several precaution measures should be observed before administration of the drug which include determination of the blood pressure range, patients with condition related to renal failure and also for physiological condition such as pregnancy which make it advisable to terminate treatment during the second and the third trimester, but the safety and efficacy of these drug to patients over 6 years and above have been determined.
This drug work best when the treatment is started immediately at the onset of the signs of heart failure, because of the side effects of the ACT inhibits which include headache, dizziness, orthostatic, hypotension and cough, with the adverse effect at the long run which include severe hypotension, syncope, angioedema and blood dysrcasis.
a reservation was made to such patient who may not tolerate this, hence an alternative was adopted . which have an action of blocking the ARBs (angiotensin receptors blocker) inhibitors which has the same mode of action as ACT inhibitors, with the approval of Valsartan and Candersarton in 2005, with a maximum recommendation dosage of 320mg/day and32mg/day respectively.
Treatments of heart failure with diuretics have being used because of the less adverse effect and their effectiveness in alleviating the symptoms of heart failure by reducing fluid volume, normal diuretics are prescribed together with the ACE inhibitors with patients presenting symptoms such as pulmonary congestion a clear indicator of water retention. An example is loop diuretic called furosemide which work even with renal malfunction, the drug function best when administered intravenously in acute heart failure in span of minutes.
Furosemide mode of action involves prevention of reabsorption in the loop of henle region for the sodium and chloride ions, however precaution should be observed before administering, by looking at potassium level, lower dose is recommended for geriatric patients, patients with pregnancy category C, neonates and developing infants should not be treated with the drug, dosage recommended for an adult is a maximum 600mg/day, furosemide have several side effect which in electrolyte imbalance and orthostatic hypotension, with the adverse effect at the long run which include; Severe hypotension, dehydrations, hypokalemia, hyponatremia and ototoxicity. Thiazide diuretics are less efficient than loop a diuretic which is reserve for patients with moderate or mild condition.
However it can be efficient when used together with loop diuretics in acute heart failure, potassium sparing diuretics have low efficacy with limited use, with the exception of aldosterone antagonist called spironolactone which have displayed reduced mortality and slow progression of advanced heart failure, the dosage is given in part but a maximum of 200mg/day is recommended, which could have the following side effect such as hyperkalemia, gynecomastia in male fatigue and dysrhythmias as an adverse effect due to hyperkalemia. References Jack . G and Sternberg . S (2010) Analysis: hospital heart attack death rate drop. Merck manual (2008) Retrieved on 8 July 2010 from http://www. merck. com/mmhe/sec03/ch025/ch025a. html. Williamson (2010) anxious heart disease patients at high risk Retrieved on 8 July 2010 from, http://www. thetherapylounge. com/hypnotherapy-news/c-4408/anxious-heart-disease-patients-at-higher-risk/.