文档介绍：Chapter 26 Drugs Used in Congestive Heart Failure
Overview of congestive heart failure
Congestive heart failure (CHF) is a condition in which the heart is unable to pump sufficient blood to meet the needs of body.
Causes of CHF: coronary artery disease, hypertention, valvular heart disease(心瓣膜病), dilated cardiomyopathy(扩张性心肌病), and congenital heart disease(先天性心脏病)
Activation of SNS
increase myocardial contractility
increase heart rate
increase systemic vascular resistance
Activation of RAS
increase systemic vascular resistance
increase production of aldosterone ----fluid retention
Pathophysiology of CHF
Treatment of congestive heart failure
1. Positive inotropic drugs(正性肌力药)
Cardiac glycosides
Sympathomimetics
Phosphodiesterase inhibitors
2. Diuretics: thiazides, aldosterone antagonists (spironolactone螺内酯)
3. Vasodilators
4. RAS inhibitors: ACEI, AT1 antagonist
-receptor blocker
Diuretics
Diuretics → volume of blood ↓→ venous pressure and the thus cardiac preload ↓→ the efficiency of the heart as a pump ↑→ cardiac output ↑, oedema ↓
Thiazides: hydrochlorothiazide 氢氯噻嗪
Loop diuretics: furosemide 呋塞米(速尿)
Spironolacton 螺内酯(anti-aldosterone , keep potassium and diuretics)
Diuretics
Diuretics remain central in controlling congestive symptoms and improving exercise capacity in patients with CHF
Congestive symptoms: elevated right-heart pressure, pulmonary venous congestion, and peripheral edema
Aldosterone Antagonists Spironolacton(螺内酯)
In CHF, Plasma aldosterone concentrations may increase to as high as 20 times the normal level.
Biological effects of aldosterone:
Salt retention
Myocardial fibrosis
Reduced myocardial norepinephrine uptake
Treatment with spironolacton is associated with mortality benefit in patients with heart failure (~30% reduction)
Dilatation of the veins→ decreases preload
Dilatation of the artery→ decreases afterload
Decrease the oxygen demand of the heart
mechanisms
Vasodilators
Nitrate esters: nitroglycerin , nitro