Oko kukuthi, kutheni kubalulekile
Inodeji ye-atrioventricular (AV) iyinxalenye ebalulekileyo yesistim sombane senhliziyo. Ilawula ukuhamba kwentshukumo yombane yamanzi kwi-atria ukuya kuma-ventricles.
Yintoni i-AV Code?
I-AV node "inkinobho" encinci yeeseli ezikhethekileyo (malunga ne-3 nge-5 mm ububanzi) esecaleni kwintliziyo, ngakwesokudla kweseyamu ye-atriyamu ekuhlanganiseni kwe-atria kunye nee-ventricle.
Umsebenzi wayo kukunceda ukulungelelanisa ukubethelwa kwe-atria kunye neepriricle ngokuphendula kwisiginali sombane senhliziyo.
Yintoni i-AV Node?
I-AV node ilawula ukuhamba kwesaziso sombane wenhliziyo ukusuka kwi-atria ukuya kuma-ventricles.
Emva kokuba umbane ugqitywe yi- node ye-sinus , isasazeka kwi-atria, okwenza i-atria ibetha. I-AV node "iqokelela" ukuba igalelo lombane kwaye, emva kokulibaziseka okufutshane, livumela ukuba lidlulele kwii-ventricles.
Ukubaluleka kweKliniki ye-AV Node
I-AV ye-AV eqhelekileyo ibalulekile ekusebenzeni kakuhle kwentliziyo. Ukulibaziseka okufutshane kwimpembelelo yombane ebangelwa yi-AV node igqugquzela umsebenzi wenhliziyo. Ukulibazisa kukuvumela ukuba i-atria iqede ukubetha, ukwenzela ukuba ama-ventricle agcwaliswe ngokupheleleyo ngegazi, ngaphambi kokuba ama-ventricles aqale ukubetha.
Ngaphezu koko, ngokungafani nakwezinye iinxalenye zombane wenkqubo yombane, ngokuphindaphindiweyo i-AV node ivuselelwa yimpembelelo kagesi, i-slower it conducts electricity.
Lo mbandela - othiwa "ukuqhutyelwa komthetho" - uba luleke kakhulu (umzekelo) i-fibrillation ye-atrial , apho i-AV node ibhobhozwa ngamakhulu emimandla yombane ngomzuzu. Ukuqhutyelwa komyalelo wokunciphisa isithintelo kunqanda ininzi yale mizamo ukuba ifike kwii-ventricles, kwaye igcina izinga lentliziyo libe yingozi.
I-AV node ixhaswe ngokugqithiseleyo yi- vagus nererve . Ukunyuka kwetayiti yentsholongwane ye-vagus (njengokuba kunokushukunyiswa nge- Valsalva maneuver ) kunokuthintela ngokukhawuleza ukuhanjiswa kwempembelelo kagesi kwi-AV node. Lo mkhangeli uncedo ekumiseni iintlobo ezininzi ze -tachycardia (SVT) ezingaphezulu .
Abanye abantu bazalwa ngeendlela ezimbini zombane ezahlukileyo kwi-AV node, enokubenza babe ne-prhythmia ebizwa ngokuba yi-AV nodal reentrant tentycardia, okanye i-AVNRT. Ungafunda apha malunga ne-AVNRT .
Izifo ze-AV node zingabangela ukulibaziseka, okanye ibinki ekhethekileyo okanye epheleleyo, ukusasazwa kweempembelelo zombane ukusuka kwi-atria ukuya kwi-ventricles-imeko eyaziwa ngokuba yi " block heart ".
Ukulibaziseka ekuqhutyweni kwe-AV node kubonakala kwi- ECG njengonyuka "IP interval". (Ixesha le-PR lilinganisa ixesha phakathi kokuphambana kweerriyati kunye nokuqhaqholwa kwamandla.) Ixesha elide le-PR, eliveliswe ukulibaziseka kwi-AV nodal conduction, ibizwa ngokuba yi-"degree degree AV block".
Ukuba ukuqhutshwa kwe-AV nodal uhamba ngokukhawuleza, ibloko yebhendi ingaqwalaselwa. Ngomgca "wesibini we-AV block" iimpembelelo ezithile zivaliwe ekufikeleleni kwii-ventricles. Nge "block block ye-AV block" zonke iimpembelelo zivaliwe.
Ngamanye amaxesha i-AV nodal nodal ibonakala ngokwaneleyo ukuvelisa i- bradycardia enamandla, kunye nokufakwa kwe- pacemaker kungafuneka. Nangona kunjalo, ibhloko yeentliziyo ezibangelwa yi-AV nodal dysfunction ngokuqhelekileyo zihambelana neziyobisi (ezifana ne- beta blockers okanye i- calcium channel blockers ), okanye ngeengxaki zonyango ezandisa i-veral verve ton tone (njenge-nasusea kunye nokuhlanza), kwaye inokuhlala iphathwa njalo ngaphandle kokuba ukuthabatha kwi-pacemaker.
Nangona kunjalo, enye imbangela ye-block nodal block ingadinga i-pacemaker esisigxina, oko kukuthi, i- myocardial infarction (ukuhlaselwa kwintliziyo) . I-AV node ithola igazi layo kwi-AV nodal nodal, apho abantu abangama-90% banesigqeba se- coronary artery .
Ngoko i-block ye-AV nodal ngenxa yesifo senhliziyo ibonakala ngokugqithiseleyo nge-coronary artery attack attack. Ngethamsanqa, kwale meko i-AV node isoloko ifumana ngokukhawuleza kwiintsuku ezimbalwa ukwenza i-pacemaker ingadingekile.
Imithombo:
Epstein AE, DiMarco JP, Ellenbogen KA, et al. I-ACC / AHA / HRS 2008 Izikhokelo zonyango olusekelwe kwiCadio Rhythm Iingqungquthela: ingxelo ye-American College of Cardiology / i-American Heart Association Task Force kwiZikhokelo zoLwazi (iKomiti yokuBhala yokuHlola i-ACC / AHA / NASPE 2002 Isikhokelo sokuHlaziya ukuFakelwa I-Cardiac Pacemakers kunye nee-Antiarrhythmia Devices): ziphuhliswe ngokubambisana ne-American Association ye-Thoracic Surgery kunye ne-Society of Thoracic Surgeons. Uhambo luka-2008; 117: e350.