Department of Physiology, Faculty of Medicine, Masaryk University, Brno1 Cardiovascular system I Organization of cardiovascular system. Blood. Arteries and veins. Microcirculation. Cardiac electrophysiology and ECG. Compendium of Physiology – autumn 2020 Tibor Stračina Compendium of Physiology2 Organization of CVS https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-17/figure-17-3 https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-20/figure-20-1 Blood Compendium of Physiology3 ̶ Blood plasma ̶ Water ̶ Ions ̶ Proteins ̶ Urea, glucose, etc. ̶ Erythrocytes ̶ Leukocytes ̶ Platelets https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-18/figure-18-1 Compendium of Physiology Red blood cells. Haemolysis ̶ Erythropoiesis ̶ Life span ̶ Degradation ̶ Function ̶ Transport (O2, CO2) ̶ Buffer (hemoglobin) Haemolysis ̶ Physical ̶ Mechanical ̶ Osmotic ̶ Thermic ̶ Chemical ̶ Biological ̶ Immune responce 4 Compendium of Physiology5 Blood groups. AB0 system ̶ Surface antigents on the RBCs ̶ AB0 system ̶ The highest imunoactivity ̶ 2 surface antigens (A, B), co-dominance ̶ 4 blood groups: A, B, AB, 0 ̶ Antibodies constantly produced ̶ Other systems: Rh, MNS, P, Kell, Lewis, Duffy, Diego 5 Compendium of Physiology6 AB0 system – slide method 6 Serum (antibodies) Anti-A Anti-B Anti-A + Anti-B Blood group Legend: Negative reaction Positive reaction 0 AB B A Compendium of Physiology7 Rh system and other systems ̶ Rh system ̶ Antigen D ̶ Anti-D antibodies ̶ Rh incompatibility (Rh- mother vs. Rh+ fetus) 7 Compendium of Physiology8 Arteries: blood pressure, R, blood flow ̶ Systemic arteries – high-pressure system ̶ Elastic arteries (low resistance, high compliance) ̶ Resistance arteries (high and regulable resistance) ̶ Pulmonary arteries – low-pressure system Compendium of Physiology9 Veins: blood pressure, R, blood flow. Venous return. Venostasis. ̶ High capacity - volume reserve ̶ Low pressure gradient ̶ Mechanisms of venous return ̶ Muscle pump ̶ Valves ̶ Blood flow (pressure) through capillaries – vis a tergo = force from behind ̶ Suction force of ventricular systole – vis a fronte = force from the front ̶ Suction force of inspiration Compendium of Physiology10 Microcirculation ̶ Net filtration pressure (Starling forces) ̶ Hydrostatic (blood) pressure in capillary ̶ Hydrostatic pressure in interstitium ̶ Osmotic pressure in capillary ̶ Osmotic pressure in interstitium https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-20/figure-20-9 Compendium of Physiology11 Heart. Cardiac muscle as an excitable tissue ̶ Excitability ̶ Task: Draw AP of working ventricular cardiomyocyte. https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-21/figure-21-1 Compendium of Physiology12 Action potential: Ventricular muscle cells https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-21/figure-21-2 Compendium of Physiology13 Cardiac automaticity. Condactive system ̶ Pacemaker aktivity ̶ SA node >> AV node >> Purkinje fibres ̶ Condactive system ̶ Fast conduction ̶ Delay (AV-His) https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-21/figure-21-2 Compendium of Physiology14 Electric vector of the heart. ECG ̶ Potential differences ̶ Summary of all partial vectors ̶ Changes in time Author: MN; https://is.muni.cz/auth/el/med/jaro2020/aVLFY0422p/um/ECG-2020-GM.pdf Compendium of Physiology15 ECG electrodes. ECG leads ̶ ECG electrode ̶ ECG lead – connection of two active exploring electrodes (bipolar lead) or one exploring electrode and one reference electrode/clamp (unipolar lead) Compendium of Physiology16 Standard 12-lead ECG ̶ 3x bipolar limb leads ̶ I, II, III ̶ 3x unipolar augmented limb leads ̶ aVR, aVL, aVF ̶ 6x unipolar chest leads ̶ V1, V2, V3, V4, V5, V6 R L F aVR aVF aVL IIIII I V V1 V6 Einthoven triangle – frontal plane horizontal plane Compendium of Physiology17 Standard 12-lead ECG record Patient‘s name; date and time of measurement Time and voltage scale Bipolar limb leads (I, II, III) Unipolar augmented limb leads (aVR, aVL, aVF) Lead II in long time scale Values from automatic analysis (TF – heart rate) Unipolar chest leads (V1 – V6) Calibration mark Compendium of Physiology18 Normal ECG curve - nomenclature ̶ Changes of voltage (mV) in time Pwave PQsegment QRScomplex STsegment Twave PQinterval QTinterval RRinterval The level of the isoline A negative deflection A positive deflection Compendium of Physiology19 ECG evaluation – basic algorithm 1. Heart rhythm (regular/irregular; sinus/junctional/ventricular/other) 2. Heart rate (a value in bpm) 3. The duration of the P wave, the PQ interval, the QRS complex, and the QT interval (in ms) 4. Position of ST segment (in isoline/elevated/depressed) 5. Transitional zone (position; lead V1 – V6) 6. Electric axis of the heart (position in degrees) Compendium of Physiology20