Difference between revisions of "Heart Failure, Treatment"

Revision as of 19:44, 25 October 2010

Introduction

Goals of Treatment

Cure
Slow/Prevent Disease Progression
Symptomatic Relief

Treatments vary from surgical correction of underlying conditions, such as correction of a PDA, to management changes and pharmacological treatments.

Management Changes

Avoid strenuous exercise
Reduced Salt Diets (Reduces Preload)
Potassium Supplements
Taurine Supplements (Cats with dilated cardiomyopathy)
L-carnitine Supplements (Dogs with dilated cardiomyopathy)
Nutraceuticals (e.g. Omega-3 fatty acids, Anti-oxidants, Co-enzyme Q10)

Heart failure patients can suffer from cardiac cachexia due to the high metabolic demands of this condition. Make sure the patient is eating enough calories per day to maintain their body weight.

Pharmacological Intervention

The following terms are usfule when desribing the effects of various pharmacological agents:

Preload=amount of maximal myocardial stretch (During Diastole)
Afterload=amount of maximal myocardial tension (During Systole)

Drug treatments can be used to:

Decrease Afterload (Increases flow by decreasing arterial tone)
Increase Myocardial Systolic Function
Increase Myocardial Diastolic Function

Decrease Preload

This decreases venous tone & fluid volume which can help to relieve congestion & edema Drugs in this class include:

Diuretics: These decrease blood volume by increasing sodium loss from the kidneys. They include loop diuretics, that act on the renal Loop of Henle such as Frusemide, and thiazide diuretics that act on the renal Distal Convoluted Tubule, such as Chlorothiazide or Hydrochlorothiazide. Potassium sparing diuretics act on the renal Collecting Duct and include Spironolactone and Amiloride.

2. Venodilation: Dilation of veins causes decreased venous pressures, blood redistribution, increased capacitance

-Venodilators

Glyceryl trinitrate

-Balanced Vasodilators

ACE inhibitors

Alpha-antagonists

Nitroprusside

Side Effects of Preload Reduction: hypovolemia, dehydration, hypokalemia, hyponatremia

Decrease Afterload

Benefit: Reduce resistance to outflow, reduce cardiac work by decreasing systolic myocardial tension, increase blood flow

Techniques

1. Arterial Vasodilators

Hydralazine

2. Balanced Vasodilators

ACE Inhibitors

enalapril (dogs & cats)

benazepril (cats)

Side Effects of ACE Inhibitors: vomiting, anorexia, diarrhea, hypotension, azotemia

Increase Myocardial Systolic Function

Benefit: Helps with dilated cardiomyopathy & mitral valve disease (Dog & Cat)

Contraindicated: Animals with hypertrophic cardiomyopathy (Dog & Cat)

Techniques

1. Positive Inotropes

Digitalis Compounds (e.g. digoxin, digitoxin)

Calcium Sensitiser/Phosphodiesterase III. Inhibitor (e.g. pimobendan)

Pure Phosphodiesterase Inhibitors (e.g. milrinone, amrinone)

Catecholamines (e.g. dobutamine, dopamine)

Advantages:

-Stimulates myocardial contractility to improve cardiac output regardless of preload

Disadvantages:

-Increased myocardial work causes increased myocardial oxygen demand

Increase Myocardial Diastolic Function

Benefit: Helps with hypertrophic cardiomyopathy and myocardial fibrosis where ventricular filling is compromised

Techniques

1. Beta Blockers (e.g. atenolol, propranolol)

2. Calcium Channel Blockers (e.g. diltiazem)

@@ Line 1: / Line 1: @@
-{{OpenPagesTop}}
+==Introduction==
-== Goals of Treatment ==
-The goals of treatment of heart failure are to either cure it, or to slow it down or prevent the progression of the disease. If no 'treatment' can be given then drugs can be used to provide symptomatic relief. Treatments vary from surgical correction of underlying conditions, such as correction of a [[Patent Ductus Arteriosus|PDA]], to management changes and pharmacological treatments.
-== Management Changes ==
+==Goals of Treatment==
+*Cure
+*Slow/Prevent Disease Progression
+*Symptomatic Relief
-Certain things owners need to be made aware of in order to prevent exacerbation of the disease include avoiding strenuous exercise and feeding reduced salt diets as this reduces preload. They may also wish to give potassium supplements or in cats with [[Dilated Cardiomyopathy|dilated cardiomyopathy]], taurine supplements. L-carnitine supplements can be given to dogs with dilated cardiomyopathy. Nutraceuticals (e.g. Omega-3 fatty acids, Anti-oxidants, Co-enzyme Q10) can also be given. <br>
+Treatments vary from surgical correction of underlying conditions, such as correction of a PDA, to management changes and pharmacological treatments.
-Heart failure patients can suffer from cardiac cachexia due to the high metabolic demands of this condition. Make sure the patient is eating enough calories per day to maintain their body weight.
+==Management Changes==
+#Avoid strenuous exercise
+#Reduced Salt Diets (Reduces Preload)
+#Potassium Supplements
+#Taurine Supplements (Cats with dilated cardiomyopathy)
+#L-carnitine Supplements (Dogs with dilated cardiomyopathy)
+#Nutraceuticals (e.g. Omega-3 fatty acids, Anti-oxidants, Co-enzyme Q10)
-== Pharmacological Intervention ==
+Heart failure patients can suffer from cardiac cachexia due to the high metabolic demands of this condition. Make sure the patient is eating enough calories per day to maintain their body weight.
-The following terms are useful when describing the effects of various pharmacological agents. These are 'Preload'. This is the amount of maximal myocardial stretch (during diastole). 'Afterload' is the amount of maximal myocardial tension (during systole).
+==Pharmacological Intervention==
+The following terms are usfule when desribing the effects of various pharmacological agents:
+*Preload=amount of maximal myocardial stretch (During Diastole)
+*Afterload=amount of maximal myocardial tension (During Systole)
 Drug treatments can be used to:
-==== Decrease Preload ====
+*Decrease Afterload (Increases flow by decreasing arterial tone)
+*Increase Myocardial Systolic Function
+*Increase Myocardial Diastolic Function
-This decreases venous tone and fluid volume which can help to relieve congestion & oedema. Drugs in this class include:
+===Decrease Preload===
+This decreases venous tone & fluid volume which can help to relieve congestion & edema
+Drugs in this class include:
+#Diuretics: These decrease blood volume by increasing sodium loss from the kidneys. They include '''loop diuretics''', that act on the renal Loop of Henle such as Frusemide, and '''thiazide diuretics''' that act on the renal Distal Convoluted Tubule, such as Chlorothiazide or Hydrochlorothiazide. '''Potassium sparing diuretics''' act on the renal Collecting Duct and include Spironolactone and Amiloride.
-'''Diuretics''': These decrease blood volume by increasing sodium loss from the kidneys. They include '''loop diuretics''', that act on the renal loop of Henle such as Frusemide, and '''thiazide diuretics''' that act on the renal distal convoluted tubule, such as Chlorothiazide or Hydrochlorothiazide. '''Potassium sparing diuretics''' act on the renal collecting duct and include Spironolactone and Amiloride.
-'''Venodilators ''', as their name suggests, dilate veins causing decreased venous pressures, blood redistribution, and increased capacitance. Venodilators include Glyceryl trinitrate and a group of drugs classified as '''balanced vasodilators''', which includes ACE inhibitors (Enalapril (dogs & cats), Benazepril (cats), alpha-antagonists and Nitroprusside.
+'''2. Venodilation''': Dilation of veins causes decreased venous pressures, blood redistribution, increased capacitance
-The side effects of preload reduction include: hypovolemia, dehydration, hypokalemia, hyponatremia.
-==== Decrease Afterload ====
+-Venodilators
-Decreasing afterload increases flow by decreasing arterial tone. This reduces resistance to outflow which reduces the cardiac workload by decreasing systolic myocardial tension and increasing systemic blood flow. Arterial vasodilators include Hydralazine or any member of the balanced vasodilators mentioned above. ACE inhibitors such as Enalapril and Benazepril are commonly used - side effects include vomiting, anorexia, diarrhea, hypotension, and [[azotaemia]].
+*Glyceryl trinitrate
-==== Increase Myocardial Systolic Function ====
-This helps with dilated cardiomyopathy and [[Degenerative Mitral Valve Disease|mitral valve disease]] (dog & cat) but is '''contraindicated''' in animals with [[Hypertrophic Cardiomyopathy|hypertrophic cardiomyopathy]] (dog & cat). '''Positive Inotropes''' can be used to stimulates myocardial contractility to improve cardiac output regardless of preload. This class of drug includes digitalis compounds (e.g. Digoxin, Digitoxin), calcium sensitisers/ phosphodiesterase III. inhibitor (e.g. Pimobendan), pure phosphodiesterase inhibitors (e.g. Milrinone, Amrinone) and catecholamines (e.g. Dobutamine, Dopamine).
+-Balanced Vasodilators
-The disadvantage of positive inotropes is that increased myocardial work causes increased myocardial oxygen demand.
+*ACE inhibitors
-==== Increase Myocardial Diastolic Function ====
+*Alpha-antagonists
-This helps with hypertrophic cardiomyopathy and myocardial fibrosis where ventricular filling is compromised. Drugs include the beta blockers (e.g. Atenolol, Propranolol) and calcium channel blockers (e.g. Diltiazem).
+*Nitroprusside
-{{Chapter}}
+Side Effects of Preload Reduction: hypovolemia, dehydration, hypokalemia, hyponatremia
-{{Mansonchapter
-|chapterlink = http://www.mansonpublishing.co.uk/book-images/9781840761856_sample.pdf
-|chaptername = Congestive Heart Failure in the Dog (part of Congestive Heart Failure in the Cat)
-|book = Small Animal Emergency and Critical Care Medicine
-|author = Elizabeth Rozanski, John Rush
-|isbn = 9781840761856
-}}
-== References ==
-Ettinger, S.J. and Feldman, E. C. (2000)''' Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat '''Volume 2 (Fifth Edition) ''W.B. Saunders Company''
+=====Decrease Afterload=====
-Ettinger, S.J, Feldman, E.C. (2005)''' Textbook of Veterinary Internal Medicine '''(6th edition, volume 2) ''W.B. Saunders Company''
+*Benefit: Reduce resistance to outflow, reduce cardiac work by decreasing systolic myocardial tension, increase blood flow
-Fossum, T. W. et. al. (2007)''' Small Animal Surgery''' (Third Edition)'' Mosby Elsevier''
+*Techniques
-Merck &amp; Co (2008) '''The Merck Veterinary Manual '''(Eighth Edition)'' Merial''
-Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine '''(Fourth Edition) ''Mosby Elsevier''
+. '''Arterial Vasodilators'''
+*Hydralazine
-{{review}}
-{{OpenPages}}
+. '''Balanced Vasodilators'''
-[[Category:Expert_Review]] [[Category:Heart_Failure]]
+*ACE Inhibitors
-[[Category:Cardiology Section]]
+enalapril (dogs & cats)
+benazepril (cats)
+Side Effects of ACE Inhibitors: vomiting, anorexia, diarrhea, hypotension, azotemia
+'''Increase Myocardial Systolic Function'''
+*Benefit: Helps with dilated cardiomyopathy & mitral valve disease (Dog & Cat)
+*Contraindicated: Animals with hypertrophic cardiomyopathy (Dog & Cat)
+*Techniques
+'''1. Positive Inotropes'''
+*Digitalis Compounds (e.g. digoxin, digitoxin)
+*Calcium Sensitiser/Phosphodiesterase III. Inhibitor (e.g. pimobendan)
+*Pure Phosphodiesterase Inhibitors (e.g. milrinone, amrinone)
+*Catecholamines (e.g. dobutamine, dopamine)
+Advantages:
+-Stimulates myocardial contractility to improve cardiac output regardless of preload
+Disadvantages:
+-Increased myocardial work causes increased myocardial oxygen demand
+'''Increase Myocardial Diastolic Function'''
+*Benefit: Helps with hypertrophic cardiomyopathy and myocardial fibrosis where ventricular filling is compromised
+*Techniques
+'''1. Beta Blockers''' (e.g. atenolol, propranolol)
+'''2. Calcium Channel Blockers''' (e.g. diltiazem)
+[[Category:To_Do_-_Cardiovascular]]