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ligand
hydrophilic
glycocalyx ion
hydrophobic
I – integral protein
R – receptor
E – enzyme
K – channel
P – pump (ATP-ase)
Membrane
molecules
Protein molecules
PLASMATIC MEMBRANE
„GATING“
Molecular biology of the cell. B. Alberts et al., Garland Science2002
Atrial depol.
PQ interv.
0,16
Isoelectrical segments
Concordance of T wave
Frequency dependence
Ta absence
Conduction system
Ventricular complex
(depol.) (repol.)
QRS
0,1
QT
0,3
HR – dependent
R L
F
50%
V
Wilson, 1934, VR, VL, VF
R L
F
87%
V´
Goldberger, 1947, aVR, aVL, aVF
R L
F
100%
Einthoven, 1913
I, II, III
(R–Q–S) in lead I., II., III.
• Eqilateral
Einthoven
triangle
Terminology QS RS
left prepondeance
(deviation)
Normal range
right prepondeance
(deviation)
ELECTRICAL AXIS – in frontal plane
ELECTRICAL AXIS OF THE HEART
Summary of all momentary vectors, which form ventricular
depolarisation loop. Expresses the direction of ventricular
activation. Reflects asymmetry in ventricular wall thickness
and the position of the heart in the chest.
PROJECTION PLANES OF CARDIAC VECTOR
AND ECG LEADS
Frontal plane
limb leads
I., II., III., aVR, aVL, aVF
Horizontal plane
V1 – V6
Both planes are shifted into the
level
of electrical centre of the heart
(0)
E – Einthoven triangle
aVR
aVL
aVFV1 V2 V3
V4
V5
V6
I.
II.
III.
0
E
P = T . 2h . r –1 Diastole: r and T rise, P first drops down, then rises up (relationship
length/tension)
P = T . 2h . r –1 Isovolumic contraction: T rises up, valves closed – increase in P
P = T . 2h . r –1 Ejection: r drops down, h rises, thus P increases even at the same T
P = T . 2h . r –1 Isovolumic relaxation: T decreases, valves closed – decrease in P
CARDIAC CYCLE
CARDIAC RESERVE = maximal CO / resting CO
CORONARY RESERVE = maximal CF / resting CF
CHRONOTROPIC (FREQUENCY) RESERVE = maximal HR / resting HR
VOLUME RESERVE = maximal SV / resting SV
4 - 7
3.5
3 - 5
1.5
CO = cardiac output
CF = coronary flow
HR = heart rate
SV = stroke volume