Copyright HEMO SAPIENS®AFTERLOAD
involves the physical forces the pump (left ventricle) has
to develop to overcome the resistive forces of the vasculature in order to push a
bolus of blood (SV) into it during every heart beat
AORTIC
Related to aorta
BIOIMPEDANCE
Electrical resistance of a body segment to a low magnitude,
high frequency measurement current.
BODY SURFACE AREA (BSA)
BSA [m
],
is an estimated (not measured) surface of patient's body.
For adults the approximate
value of BSA can be calculated as:
BSA = {[height(cm) + weight(kg)] - 60}/100
BSA
see Body Surface Area
CARDIAC INDEX
Cardiac Index (CI) is an indexed perfusion-significant
global blood flow:
CI = CO/BSA. Its dimension is l/min/m
CARDIAC OUTPUT (CO)
CO is the amount of blood the heart pumps in one
minute. The resting normal value of CO in all mammals is related to their weight
at the rate 0.1 l/min/kg. In order to have only one normal range for patients of
different body habitus, its indexed value, called Cardiac Index, is used in hemodynamics.
CARDIODYNAMIC PARAMETERS
are these parameters that do not include a
simultaneous processing of blood pressure and blood flow (i.e., hemodynamic
parameters)
CHRONOTROPE
a pharmacological agent affecting the heart rate; positive
chronotropes increase, negative chronotropes decrease the heart rate.
CI
see Cardiac Index
CO
see Cardiac Output
CONTRACTILITY
is related to the rate of shortening of myocardial fibers
in time during mechanical systole, encompassing both the isovolumic and the ejection
phase. The isovolumic contractility is affected only by inotropes, the ejection phase
contractility is affected both by inotropes and by the effects of intravascular volume
(volemia) - i.e., by the Frank-Starling Law.
DIURESIS
reduction of blood volume by pharmacological agents called
diuretics
EF
see Ejection Fraction
EJECTION FRACTION [%]
EF is the percentage of blood volume held within
the left ventricle at the end of diastole (the End-diastolic Volume, EDV) which is
ejected into the vasculature as the Stroke Volume, SV.
EF = 100 (SV/EDV)
EJECTION PHASE CONTRACTILITY INDEX (EPCI)
EPCI = (dZ/dt)max x
TFC. The dimension is one/sec. EPCI, directly measured by TEB, represents a normalized
combination contribution of a maximum rate of aortic distention (a plethysmographic
signal) and a maximum rate of aortic blood velocity increase (a maximum rate of alignment
of erythrocytes).
HEART RATE (HR)
HR is the number of heart beats in one minute.
HEMODYNAMICS
deals with simultaneously acquired and processed blood
flow and blood pressure.
Hemodynamic state is represented by blood pressure @
blood flow. The per-beat hemodynamically-significant blood pressure is the Mean Arterial
Pressure (MAP) and hemodynamically-significant blood flow is Stroke Index (SI). A
new hemodynamic state is formed for every heart beat.
Only instrumentation processing
simultaneously acquired and processed blood flow and blood pressure can be
called hemodynamic instrumentation.
HEMOCONCENTRATION
a supranormal level of Hgb
HEMODILUTION
infranormal level of Hgb; therapy involves transfusion
of packed red blood cells
HEMOGLOBIN (Hgb)
Its dimension is gram/deciliter
Hgb
see Hemoglobin
HR
see the Heart Rate
HYPOCHRONOTROPY
inadequate compensatory effect of HR which results in
an infranormal value of CI; therapy involves administration of positive chronotropes
HYPODYNAMIC
Infranormal level of SI (for adults: SI < 35 m/m
)
HYPOINOTROPY
inadequate level of inotropic state; therapy involves administration
of positive inotropes
HYPOTENSION
infranormal value of MAP (for adults: MAP < 70 Torr)
HYPOVOLEMIA
inadequate level of blood volume; therapy involves volume
expansion (volume loading)
HYPERCHRONOTROPY
current level of HR produces a supranormal value of
CI; therapy involves administration of negative chronotropes
HYPERDYNAMIC
supranormal level of SI (for adults: SI > 65 ml/m
)
HYPERINOTROPY
excessive level of inotropic state; therapy involves administration
of negative inotropes
HYPERTENSION
supranormal value of MAP (for adults: MAP > 105 Torr)
HYPERVOLEMIA
excessive level of circulating blood volume; therapy involves
administration of diuretics
INOTROPIC STATE INDEX (ISI)
ISI = (d
Z/dt
)max
x TFC. The dimension is on1/sec/sec. ISI represents a normalized image of maximum
acceleration of aortic blood flow, described in cardiology literature as a parameter
affected only by inotropes. ISI is an end-result of the left ventricular impulse,
produced at the instant of aortic valve opening by a quadratic rate and magnitude
of isovolumic pressure rise.
INOTROPY (INOTROPIC STATE)
is related to a level of pharmacologic agents
(inotropes) within blood, affecting the rate of contraction of myocardial fibers.
Positive inotropes increase and negative inotropes decrease the myocardial contractility.
INTRAVASCULAR VOLUME
circulating volume of blood involved in therapeutic
decisions
LEFT STROKE WORK INDEX (LSWI)
LSWI is a normalized amount of physical
work the heart expends over one heart beat interval. Its dimension is g.m/m
.
LSWI is directly related to myocardial oxygen consumption/beat. Since the majority
of oxygen is burned during the isovolumic contraction and the rest during the ejection
phase, it also is related to a combined level of myocardial contractility over the
entire mechanical systole.
LSWI
se Left Stroke Work Index
MAP
see Mean Arterial Pressure
MEAN ARTERIAL PRESSURE (MAP)
is the value of pressure which would exist
at the output node of the heart if there would be no arterial pulsations.
Its
approximate value is MAP = {[(Systolic - Diastolic)/3] + Diastolic}.
In HOTMAN™
F11X System MAP is directly measured by the built in NIBP device.
NIBP
Noninvasive Blood Pressure
NONINVASIVE
a technique which does not require a penetration of skin
to perform a physiologic measurement
NORMOCHRONOTROPY
a compensatory effect of HR produces CI within a normal
range
NORMODYNAMIC
SI within a normal range (35 - 65 ml/m
)
NORMOINOTROPY
normal level of inotropic state
NORMOTENSION
MAP within a normal range (70 - 105 Torr)
NORMOVASOACTIVITY
SSVRI within a normal range
NORMOVOLEMIA
normal level of circulating blood volume (does not count
the additional blood retained in reservoirs, such as in spleen)
PERFUSION
continuous supply of oxygen through adequate blood flow to
the tissues
PRELOAD
involves the inertia forces of inflowing blood into the left
atrium during diastole which stretch its fibers, thus storing mechanical energy in
them; more stretched fibers (increased preload) contract during systole with a higher
force (a mechanically produced an increase in contractility known as the Frank-Starling
Law)
PULSE OXIMETRY
a noninvasive technique using a finger clip with optotransmitter
and sensor to determine the approximate percentage of erythrocytes in arterial blood
which carry oxygen to tissues - see SpO
RESPIRATORY RATE (RR)
RR is the number of breaths per minute.
RR
see Respiratory Rate
SaO
percentage
of oxygenated red blood cells in arterial blood; this parameter is obtained in a
blood laboratory from a sample of arterial blood and may be approximated by a continuous
measurement of SpO
SpO
see
Pulse Oximetry
SI
see Stroke Index
SSVRI
see Stroke Systemic Vascular Resistance Index
STROKE INDEX (SI)
SI is the indexed volume of blood expelled by the
left ventricle over one heart beat interval (i.e. Stroke Volume indexed by BSA)[ml/m
].
STROKE SYSTEMIC VASCULAR RESISTANCE INDEX (SSVRI)
SSVRI is a per-beat
measure of afterload. Its physical dimension is dyn.sec.cm-5.m
,
however, in HOTMAN terminology a shorter term called Fluidic Ohm [F
],
is used.
STROKE VOLUME (SV)
SV is the amount of blood ejected by the left ventricle
into the vasculature over one heart beat interval (ml/beat).
TFC
see Thoracic Fluid Conductivity (or Content)
THORACIC
as related to the thorax
THORACIC FLUID CONDUCTIVITY (TFC) [1/
]
total
conductivity of thorax, representing a conductivity contribution of intravascular,
intraalveolar and interstitial compartments; for instance, a supranormal value indicates
an excess of fluids within the thoracic cavity, however, cannot pinpoint in which
compartment(s) the fluids are.
VASOCONSTRICTION
supranormal value of SSVRI (excessive afterload); therapy
involves administration of vasodilators or ACE (Angiotensin Converting Enzyme) Inhibitors.
VASODILATION
infranormal value of SSVRI; therapy involves administration
of vasoconstrictors
VOLEMIA
status of circulating intravascular volume (please note that
it is not equal to total blood volume)
VOLUME
see Intravascular Volume
VOLUME EXPANSION (VOLUME LOADING)
a therapy instituted to correct detected
hypovolemia
VOLUME REDUCTION (DIURESIS)
a therapy instituted to correct detected
hypervolemia (volume overload)
Z [
]
a
commonly used symbol for electrical impedance