preload and afterload are affected

contractility problem = backup = more fluid trying to go through the the pipe = inadequate CO

can decrease symptoms and increase symptoms

(increase bradykinin = vasodilation)

dilate arterial and decrease aldosterone = decrease afterload and preload (increase SV)

studies have shown that carvedilol, metoprolol, and bisoprolol can decrease mortality in certain patients

worsening heart failure may occur initially; improvement may take months

decrease HR, decrease BP = decrease contractility

study of patients on spir. found that they had decreased visits to the hospital for heart failure and decreased mortality

requires careful monitoring of serum potassium and renal function

decrease Blood volume = decrease preload and afterload

1) angiotensin receptor blockers

2) hydralazine and isosorbide dinitrate (combination of an arterial dilator and a venous dilator) - African american

3) eplerenone approved for heart failure following acute myocardial infarction in certain cases

(CCB = decrease impuls to SA node= decrease HR)

increased contractility = shift curve upwards (preload) - - DIRECT EFFECTS ON HEART

used mainly in heart failure and certain arrhythmias such as a. fib.

1) increases contractility - inhibits sarcolemmal Na,K-ATPase - binding enhanced by hypokalemia

- increase intracellular Na and decreased intracell K = = increased intracellular Ca++ (figure on pg 252)

2) vagal stimulation = decrease HR (tx for supraventricular tachyarrhythmias, such as a. fib)

3) decrease sympathetic NS activity at theraputic levels; increase SNS at higher doses

effects on heart can be direct or indirect: beneficial effect in atrial fib (decreased vent. rate), but arrhythmias and heart block possible at toxic levels

increased t_1/2 with renal insufficiency

Adverse effects:

1) Cardiac toxicity = arrhythmias and/or heart block

2) GI = anorexia, nausea and vomiting, diarrhea

3) CNS - blurred vision, abnormal color vision (see Halos around lights - think van Gogh); confusion

4) manage K and monitor heart arrhythmia

Electorlyte disturbances: hypokalemia, hypercalcemia, hypomagnesemia

Drug interactions:

1) thiazide or loop = hypokalemia

2) quinidine = increase plasma digoxin concentration

3) verapamil or amiodarone = increase plasma dig. conc.

4) antacids, kaolin-pectin, cholestyramine = decreased plasma dig concentration

Beta-1 agonist - used in acute pulm edema and no response to lasix

may increase CO with less reflex tachycardia than occurs with nonselective beta agonists such as isoproterneol

possible adverse effects:

1) excessive increase in HR

2) arrhythmias

ONLY IV for acute heart failure

decreases PWP, decrease vasc. R, increase CO

inhibits phosphodiesterase (type 3) = increase cAMP = increased contractility and vasodilation

adverse: arrythmias

recombainant human B-type natriuretic peptide; hBNP

increase cGMP

approved for use in certain patients with actue decompensated heart failure

decreased PWP and dyspnea

increase action on particulate guanylate cyclase receptor = increased cGMP = Smooth muscle relaxation

adverse effects: hypotension; reports of renal damage and death

(remember - BNP is a test for heart failure)