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)