Lub myocardial cell membrane yog semi-permeable membrane.Thaum so, qee tus naj npawb ntawm cov cations zoo raug teeb tsa sab nraum daim nyias nyias.Tib tus naj npawb ntawm cov anions tsis zoo yog npaj rau hauv daim nyias nyias, thiab cov peev txheej ntxiv-membrane yog siab dua li daim nyias nyias, uas yog hu ua lub xeev polarization.Thaum so, cov cardiomyocytes nyob rau hauv txhua feem ntawm lub plawv yog nyob rau hauv ib tug polarized lub xeev, thiab tsis muaj peev xwm sib txawv.Lub peev xwm nkhaus taug qab los ntawm lub kaw lus tam sim no yog ncaj, uas yog txoj kab equipotential ntawm qhov chaw electrocardiogram.Thaum cov cardiomyocytes raug txhawb los ntawm ib qho kev siv zog, permeability ntawm cell membrane hloov thiab ntau cov cations infiltrate rau hauv daim nyias nyias nyob rau hauv ib lub sij hawm luv luv, thiaj li hais tias lub peev xwm nyob rau hauv daim nyias nyias hloov ntawm qhov tsis zoo mus rau qhov tsis zoo.Cov txheej txheem no hu ua depolarization.Rau tag nrho lub plawv, lub peev xwm hloov ntawm cardiomyocytes los ntawm endocardial mus rau epicardial sequence depolarization, lub peev xwm nkhaus taug qab los ntawm cov ntaub ntawv tam sim no hu ua depolarization nthwv dej, uas yog, P yoj thiab ventricle ntawm lub atrium ntawm qhov chaw electrocardiogram QRS yoj.Tom qab lub cell raug tshem tawm tag nrho, cov cell membrane tso tawm ntau cov cations, ua rau lub peev xwm hauv daim nyias nyias hloov ntawm qhov zoo mus rau qhov tsis zoo thiab rov qab mus rau qhov qub polarization xeev.Cov txheej txheem no yog ua los ntawm epicardium mus rau endocardium, uas yog hu ua repolarization.Ib yam li ntawd, qhov muaj peev xwm hloov pauv thaum lub sij hawm repolarization ntawm cardiomyocytes tau piav qhia los ntawm lub kaw lus tam sim no raws li lub polar yoj.Txij li thaum cov txheej txheem repolarization yog qhov qeeb, qhov nthwv dej ntawm repolarization qis dua li qhov depolarization nthwv dej.Lub electrocardiogram ntawm lub atrium yog tsawg nyob rau hauv lub atrial yoj thiab yog faus rau hauv lub ventricle.Lub ncov qaumteb qabteb ntawm lub ventricle tshwm li T yoj ntawm lub electrocardiogram nto.Tom qab tag nrho cov cardiomyocytes tau repolarized, lub xeev polarization tau rov qab los dua.Tsis muaj qhov sib txawv ntawm cov hlwb myocardial hauv txhua qhov, thiab qhov chaw electrocardiogram tau sau tseg rau hauv kab equipotential.
Lub plawv yog peb-dimensional qauv.Txhawm rau kom muaj kev cuam tshuam cov hluav taws xob ua haujlwm ntawm ntau qhov chaw ntawm lub plawv, cov electrodes tau muab tso rau hauv ntau qhov chaw ntawm lub cev los sau thiab cuam tshuam cov hluav taws xob ua haujlwm ntawm lub plawv.Nyob rau hauv niaj hnub electrocardiography, tsuas yog 4 limb lead electrodes thiab V1 rau V66 thoracic lead electrodes feem ntau yog muab tso rau, thiab ib tug pa 12-lead electrocardiogram yog kaw.Ib qho txhuas txhuas sib txawv yog tsim los ntawm ob lub electrodes los yog nruab nrab ntawm cov electrode thiab lub hauv paus muaj peev xwm kawg thiab txuas nrog rau qhov zoo thiab qhov tsis zoo ntawm electrocardiograph galvanometer los ntawm cov hlau lead los sau cov hluav taws xob ua haujlwm ntawm lub plawv.Cov hlau lead bipolar yog tsim los ntawm ob lub electrodes, ib qho txhuas yog ib tug zoo ncej thiab ib tug lead ua tsis zoo ncej.Cov kab mob bipolar muaj xws li I lead, II lead thiab III lead;monopolar lead yog tsim los ntawm cov electrode thiab lub hauv paus muaj peev xwm kawg, qhov twg cov electrode ntes yog tus ncej zoo thiab lub hauv paus muaj peev xwm kawg yog tus ncej tsis zoo.Lub hauv paus hluav taws xob kawg yog qhov sib txawv uas tau sau tseg ntawm qhov tsis zoo electrode yog qhov me me, yog li qhov tsis zoo electrode yog qhov txhais tau tias ntawm qhov sib npaug ntawm qhov muaj peev xwm ntawm cov hlau lead ntawm lwm ob ceg, tshwj tsis yog rau kev sojntsuam electrode.
Lub electrocardiogram sau qhov nkhaus ntawm qhov hluav taws xob dhau sijhawm.Lub electrocardiogram tau sau rau ntawm daim ntawv sib koom ua ke, thiab daim ntawv sib koom ua ke yog tsim los ntawm cov hlwb me ntawm 1 hli dav thiab 1 hli hauv qhov siab.Lub abscissa sawv cev rau lub sij hawm thiab lub ordinate sawv cev rau voltage.Feem ntau kaw ntawm 25mm / s ntawv ceev, 1 daim phiaj me me = 1mm = 0.04 vib nas this.Lub ordinate voltage yog 1 daim phiaj me me = 1 hli = 0.1 mv.Cov kev ntsuas ntawm lub electrocardiogram axis feem ntau suav nrog txoj kev pom, txoj hauv kev, thiab txoj kev saib lub rooj.Lub plawv tsim ntau yam galvanic vector vectors nyob rau hauv tus txheej txheem ntawm depolarization thiab repolarization.Cov galvanic ob peb vectors nyob rau hauv cov lus qhia sib txawv yog ua ke rau hauv ib lub vector los tsim ECG vector ntawm tag nrho lub siab.Lub plawv vector yog peb-dimensional vector nrog frontal, sagittal, thiab kab rov tav dav hlau.Feem ntau siv kho mob yog cov kev taw qhia ntawm ib feem vector projected ntawm lub frontal dav hlau thaum lub sij hawm ventricular depolarization.Pab txiav txim seb lub plawv hluav taws xob ua haujlwm li cas.
Post lub sij hawm: Aug-24-2021