Basic Hemodynamic
description
Transcript of Basic Hemodynamic
Basic HemodynamicsBasic Hemodynamics
Objectives
• The learner will be able to identify the
structures of the heart.
Right-side AnatomyRight-side Anatomy
• Vena cava• Right atrium• Tricuspid valve• Right ventricle• Pulmonic valve
Middle AnatomyMiddle Anatomy
• Pulmonary artery• Pulmonary
capillary• Pulmonary vein
Left-side AnatomyLeft-side Anatomy
• Left atrium• Mitral valve• Left ventricle• Aortic valve
ObjectivesObjectivesThe learner will be able to state the
definition ofbasic hemodynamic terms :• Stroke volume, stroke volume index• Ejection fraction• Cardiac output, cardiac index• Preload• Afterload• Contractility
Stroke Volume (SV)Stroke Volume (SV)Definition• The volume of blood ejected by the ventricle with each heartbeat.
Normal Value• 60-70 mL
Stroke Volume Index Stroke Volume Index (SVI)(SVI)
Definition• Stoke volume indexed to BSA
Formula• SI = Stroke Volume / Body Surface Area• SI = SV / BSA
Normal value• 25 – 45 mL / m2
Ejection FractionEjection Fraction
• EF = end diastolic volume – end systolic volume
end diastolic volume
• Normal range = 60-75% of end diastolic volume
Cardiac Output (CO)Cardiac Output (CO)
Definition The volume of blood ejected from the ventricle over 1 minute.
Formula CO = heart rate x stroke volume CO = HR x SV
Normal Value 4 - 6 Liters / min
Cardiac Index (CI)Cardiac Index (CI)
Definition CO indexed against body size
Formula CI = Cardiac Output / Body Surface Area CI = CO / BSA
Normal Value 2.5 - 4.0 Liters / min / m2
CO/ CICO/ CI
Causes :
MI Shock HR SV (-) inotropes
vascular resistance Cardiac tamponade Hypovolemia Valvular heart disease High PEEP
CO / CICO / CI
CausesCauses : Hypertension vascular resistance Pulmonary edema metabolic state Positive inotropes
Cardiac Output (CO)Cardiac Output (CO)
Myocardial OxygenMyocardial Oxygen
Heart RateHeart Rate
HR MVO2 demand
Preload
Definition• Volume in ventricle at
end diastole.
OR• Pressure exerted on
walls of ventricle at end diastole.
PreloadPreload
Clinical Significance• Represents fluid returning to heart• Also known as “filling pressure” preload, MVO2 demand
PreloadPreload
Measurement• Preload is assessed by measuring
the filling pressure of each ventricle.
• Right ventricle preload CVP• Left ventricle preload PAOP
AfterloadAfterloadDefinition Amount of pressure the ventricle must work against during systole to open the valve.
AfterloadAfterload
Clinical significanceClinical significance afterloadafterload work of the heartwork of the heart MVO2 demandMVO2 demand
AfterloadAfterload
Factors that increase afterload: Vasoconstriction Valvular stenosis blood volume
AfterloadAfterload
Factors that decrease afterloadFactors that decrease afterload VasodilationVasodilation
AfterloadAfterload
MeasurementMeasurement Afterload is assessed by measuring Afterload is assessed by measuring
thethe resistance in the ventricle duringresistance in the ventricle during systolic ejection.systolic ejection.
Right ventricle afterload PVR Left ventricle afterload SVR
Systemic Vascular Resistance Systemic Vascular Resistance (SVR)(SVR)
DefinitionDefinition The resistance the left ventricleThe resistance the left ventricle
must pump against to eject itsmust pump against to eject its
volumevolume
This resistance is created by theThis resistance is created by the
systemic arteries and arteriolessystemic arteries and arterioles
Systemic Vascular Resistance Systemic Vascular Resistance (SVR)(SVR)
Formula [ (MAP – CVP) / CO ] x 80
Normal Value 800-1200 dynes/sec/cm-5
Systemic Vascular Systemic Vascular Resistance (SVR)Resistance (SVR)
Clinical Significance SVR represents left ventricle
afterload SVR, MVO2 demand SVR, Cardiac Output SVR, Cardiac Output
Systemic Vascular Systemic Vascular Resistance (SVR)Resistance (SVR)
CausesCauses:: VasoconstrictionVasoconstriction Catacholamine releaseCatacholamine release HypertensionHypertension Cardiogenic shockCardiogenic shock Cardiac tamponadeCardiac tamponade
Systemic Vascular Resistance Systemic Vascular Resistance (SVR)(SVR)
Causes Causes :: VasodilationVasodilation Vasodilator therapyVasodilator therapy Septic shock (hyperdynamic)Septic shock (hyperdynamic)
Pulmonary Vascular Resistance Pulmonary Vascular Resistance (PVR)(PVR)
DefinitionDefinition The resistance the right ventricle The resistance the right ventricle
mustmust
pump against to eject its volumepump against to eject its volume
This resistance is created by theThis resistance is created by the
pulmonary arteries and arteriolespulmonary arteries and arterioles
Pulmonary Vascular Pulmonary Vascular Resistance (PVR)Resistance (PVR)
Formula [ (PAM – PAOP ) / CO ] x 80
Normal Value 100-250 dynes/sec/cm-5 Normally one sixth of SVR
Pulmonary Vascular Resistance Pulmonary Vascular Resistance (PVR)(PVR)
Clinical SignificanceClinical Significance PVR represents right ventricle PVR represents right ventricle
afterloadafterload
Pulmonary Vascular Pulmonary Vascular Resistance (PVR)Resistance (PVR)
Causes of Causes of PVRPVR Pulmonary vessel constriction due Pulmonary vessel constriction due
toto
PaO2PaO2
PaCO2PaCO2 Pulmonary embolusPulmonary embolus
Contractility
Definition The heart’s contractile force or muscle strength
ContractilityContractility
Factors that influence contractility: Starling’s Law Sympathetic nervous system Pharmacologic agents
Starling’s LawStarling’s Law
The force of ventricular ejection isThe force of ventricular ejection is
related torelated to :: The volume in the ventricle atThe volume in the ventricle at
enddiastolicenddiastolic
(preload).(preload). The amount of myocardial stretchThe amount of myocardial stretch
placed on the ventricle.placed on the ventricle.
Sympathetic Nervous Sympathetic Nervous SystemSystem
SNS fibers are found throughoutSNS fibers are found throughout
the atria and ventriclesthe atria and ventricles The most important regulatoryThe most important regulatory
factor for myocardial contractilityfactor for myocardial contractility
Pharmacologic agentsPharmacologic agents
Inotrope ino = strength tropy = enhancing
Positive inotrope = stronger contraction Negative inotrope = weaker contraction
Positive InotropesPositive Inotropes
digoxindigoxin epinephrineepinephrine dopamine (Intropin)dopamine (Intropin) dobutamine (Dobutrex)dobutamine (Dobutrex) inamrinone (Inocor)inamrinone (Inocor) milrinone (Primacor)milrinone (Primacor)
Negative InotropesNegative Inotropes
lopressorlopressor amiodarone (Cordarone)amiodarone (Cordarone) diltiazem (Cardizem)diltiazem (Cardizem) verapamil (Calan)verapamil (Calan) procainamide (Pronestyl)procainamide (Pronestyl)
Hemodynamic ProfilesHemodynamic Profiles