Heart failure
Dr Rafat Mosalli Dr Rafat Mosalli
Objectives
DefinitionDefinition PathophysiologyPathophysiology Age specific CausesAge specific Causes Clinical picturesClinical pictures InvestigationsInvestigations TreatmentTreatment
Definition
Difficult to defineDifficult to define It is not a diagnosis, but rather It is not a diagnosis, but rather
constellation of clinical symptoms and constellation of clinical symptoms and signs due to various causessigns due to various causes
Inadequate O2 delivery by the heart to Inadequate O2 delivery by the heart to meet the demand of the bodymeet the demand of the body
O2 delivery=O2 blood content +COPO2 delivery=O2 blood content +COP
Cardiovascular - Basic
Preload
Amount of volume filling ventricles during Amount of volume filling ventricles during diastolediastole
Proportional to volume statusProportional to volume status Increasing preload=increases stroke Increasing preload=increases stroke
volume (in general)volume (in general)
Preload Problems
Either there is Either there is not enoughnot enough preload preload
oror
The heart The heart needs moreneeds more than usual than usual
Too little or heart need more?
DehydrationDehydration Blood LossBlood Loss Post-operative blood lossPost-operative blood loss Third Spacing due to Decreased oncotic Third Spacing due to Decreased oncotic
pressure or Vascular leak.pressure or Vascular leak. Hyper dynamic circulationHyper dynamic circulation
Back to Preload - treatment
CrystalloidsCrystalloids
vs.vs.
ColloidsColloids
Crystalloids
Isotonic Fluid :Isotonic Fluid :
Normal SalineNormal Saline– 154 mEq NaCl/l
Lactated RingersLactated Ringers– 130mEq Na+
– 4mEq K+
– 3mEq Ca+2
– 109mEq Cl-
– 28mEq Lactate
Colloids
Oncotic propertiesOncotic properties More likely to stay intravascularMore likely to stay intravascular Longer duration of actionLonger duration of action
Commonly used colloids
5% Albumin5% Albumin 25% Albumin25% Albumin Plasma - FFPPlasma - FFP Packed Red Blood Cells (PRBC’s)Packed Red Blood Cells (PRBC’s)
Back to our diagram
Contractility
Somewhat dependent on preload Somewhat dependent on preload Impaired Secondary toImpaired Secondary to: : infectioninfection metabolicmetabolic hypoxia, ischemiahypoxia, ischemia surgerysurgery
How else can we affect contractility?
Adrenergic ReceptorsAdrenergic Receptors
Alpha receptors
Peripheral vasculaturePeripheral vasculature Stimulation causes vasoconstrictionStimulation causes vasoconstriction Increase SVR and afterloadIncrease SVR and afterload
Beta-1 receptors
- Heart- Heart Stimulation leads to a cascade of activityStimulation leads to a cascade of activity Activates adenylate cyclaseActivates adenylate cyclase Increases cAMP productionIncreases cAMP production This increases CaThis increases Ca+2+2 entry into the cell entry into the cell Increases strength of contraction (inotropy) and Increases strength of contraction (inotropy) and
rate of contraction (chronotropy)rate of contraction (chronotropy)
Beta-2 receptors
- lungs- lungs Located in the lungs and peripheral Located in the lungs and peripheral
vasculaturevasculature Stimulation causes smooth muscle Stimulation causes smooth muscle
relaxation relaxation – Bronchodilation in the lungs– Vasodilation in peripheral vasculature
Adrenergic Agonists: drugs
DopamineDopamine DobutamineDobutamine EpinephrineEpinephrine
Dopamine
Alpha, beta and dopaminergic agonistAlpha, beta and dopaminergic agonist
Effects:Effects:– ‘renal’ dose– Middle range: more beta– Higher range: alpha starts to predominate
Use: inotrope, vasoconstrictionUse: inotrope, vasoconstriction
Dobutamine
1 selective1 selective
Effect: increased inotropy and chronotropyEffect: increased inotropy and chronotropy Use: to increase contractilityUse: to increase contractility
Epinephrine
works at all receptors works at all receptors >>
Remember that diagram?
Afterload
Refers to work against which the heart is Refers to work against which the heart is contractingcontracting
Either :an immediate obstruction such as Either :an immediate obstruction such as valvular valvular stenosis or hypertrophystenosis or hypertrophy
Or related to Or related to systemicsystemic vascular resistance vascular resistance As you might imagine decreasing the afterload As you might imagine decreasing the afterload
will help the heart to contractwill help the heart to contract
Afterload Reduction: drugs
NitroprussideNitroprusside NitroglycerinNitroglycerin Nitric OxideNitric Oxide
Who needs afterload reduction?
Decreases force against which heart has Decreases force against which heart has to contractto contract
Poor LV function or for patients with aortic Poor LV function or for patients with aortic insufficiency or mitral regurgitationinsufficiency or mitral regurgitation
Again back to the diagram:
Heart Rate
We rarely manipulate heart rate(aside from We rarely manipulate heart rate(aside from arrhythmias)arrhythmias)
heart blockheart block
drug:Isoproteronoldrug:Isoproteronol
Back to the Diagram
BP = CO x SVRBP = CO x SVR We’re finally on SVR - systemic vascular We’re finally on SVR - systemic vascular
resistanceresistance
Systemic Vascular Resistance
Remember SVR also contributes to afterloadRemember SVR also contributes to afterload In general, increasing SVR will increase In general, increasing SVR will increase
afterload and decrease cardiac outputafterload and decrease cardiac output Since this patient population needs improved Since this patient population needs improved
CO we usually avoid increasing afterload, CO we usually avoid increasing afterload,
Drugs that increase SVR
Alpha agonists,Alpha agonists, primarily primarily EpinephrineEpinephrine
– We already talked about this
NorepinephrineNorepinephrine PhenylephrinePhenylephrine
causes
First week of life:First week of life: Obstructive lesion: COA,AS,HLHS, PS,TAPVRObstructive lesion: COA,AS,HLHS, PS,TAPVR Volume overload lesion: TR,PR,PDA ,AVMVolume overload lesion: TR,PR,PDA ,AVM Others( myocardial contractility dysfunction,arrythmia)Others( myocardial contractility dysfunction,arrythmia)
1-4 weeks:1-4 weeks: As Above + As Above + shunt shunt lesions (VSD,PDA)lesions (VSD,PDA)
Causes
>4 weeks>4 weeks::Shunt lesions as above, coronary and myocardial diseasesShunt lesions as above, coronary and myocardial diseases
at any age:at any age:-Myocardial & pericardial diseases -Myocardial & pericardial diseases
-Arrhythmia( SVT,heart block)-Arrhythmia( SVT,heart block)
-Sepsis,acidosis,hypoxia-Sepsis,acidosis,hypoxia
-Metabolic (endocrine,Glycogen storage type2)-Metabolic (endocrine,Glycogen storage type2)
-Drugs-Drugs
-Severe anemia-Severe anemia
- Tumors- Tumors
Age specific causes: summary
1-1-NeonatesNeonates Obstructive and ductal dependant lesionsObstructive and ductal dependant lesions
2-2-Post neonatalPost neonatal Shunt lesionsShunt lesions Myocardial contractility diseasesMyocardial contractility diseases
Signs and symptoms :
Impaired Myocardial performanceImpaired Myocardial performance::Shock, feeding problems, sweating, FTT, pallor, rhythm Shock, feeding problems, sweating, FTT, pallor, rhythm
problems, Cardiomegaly, gallop rhythmproblems, Cardiomegaly, gallop rhythm
Pulmonary congestionPulmonary congestion::Dyspnea, cyanosis, wheezing, tachypnea, rales,coughDyspnea, cyanosis, wheezing, tachypnea, rales,coughRespiratory acidosisRespiratory acidosis
Systemic venous congestionsSystemic venous congestionsEdema ,hepatomegaly, neck vein distentionEdema ,hepatomegaly, neck vein distention
Specific causeSpecific cause
diagnosis
HxHx Clinical examClinical exam Investigations:Investigations:
Blood workBlood work
CXRCXR
EKGEKG
ECHOECHO
Treatment
Depend on the pathophysiology Depend on the pathophysiology
Aim:Aim: Increase Increase PreloadPreload Afterload Afterload reductionreduction Correct Correct Myocardial Myocardial depressants:depressants: enhance enhance MyocardialMyocardial contractility contractility
Treatment
Underlying cause(sepsis,CHD)Underlying cause(sepsis,CHD) RestRest O2O2 Diet and growth follow-upDiet and growth follow-up MedicationsMedications::InotropesInotropesDigoxineDigoxineVasodilator therapyVasodilator therapyDiuretics (Furosemide)Diuretics (Furosemide)