Umutima Ufite Ikibazo cya Pulmonary Valve Stenosis: Ibimenyetso, Impamvu, n'Uko Uvuzwa

Pulmonary valve stenosis ni ikibazo cy'umutima aho umusemburo wa pulmonary (umusemburo ufungura n'ugafunga mu mutima) uba waragabanyijwe, bigatuma amaraso agorana kugera mu mwijima. Tekereza nk'umuhanda ufunze, bigatuma abantu batagendamo neza.

Ubu bugabana butuma umutima wawe ukora cyane kugira ngo utume amaraso anyura muri uwo muhanda muto. Nubwo byumvikana bibi, abantu benshi bafite pulmonary valve stenosis yoroheje babaho ubuzima busanzwe, kandi n'ibibazo bikomeye bishobora kuvurwa neza hifashishijwe iterambere rya siyansi mu buvuzi.

Ni iki Pulmonary Valve Stenosis?

Pulmonary valve stenosis ibaho iyo umusemburo uri hagati y'igice cy'umutima cy'iburyo (right ventricle) n'umuyoboro w'amaraso ujya mu mwijima (pulmonary artery) udatangira neza. Uyu musemburo uba nk'umuhanda ufungura uruhande rumwe, ugatuma amaraso ava mu mutima ajya mu mwijima gufata umwuka.

Iyo uyu musemburo uba waragabanyijwe, igice cy'umutima cy'iburyo kigomba gukora cyane kugira ngo gitume amaraso anyura muri uwo muhanda muto. Ibi bikorwa byinshi bishobora gutuma umutima uhindagurika ukaba ukomeye, kandi bikaba byanagabanya imbaraga zawo.

Iki kibazo kibaho kuva umuntu akiri mu nda, nubwo ibimenyetso bishobora kutaboneka kugeza mu myaka y'ubukure. Ubukana bwacyo bushobora kuba buke cyane ku buryo budakora ku buzima bwa buri munsi, cyangwa bukaba bukomeye bikaba ngombwa kuvurwa.

Ibimenyetso bya Pulmonary Valve Stenosis ni ibihe?

Abantu benshi bafite pulmonary valve stenosis yoroheje nta bimenyetso bagira, kandi bashobora kutamenya ko bafite icyo kibazo. Ariko, uko ubu bugabana bukomeye, umubiri wawe uzatanga ibimenyetso bigaragaza ko umutima wawe ukora cyane.

Ibimenyetso bisanzwe ushobora kubona birimo:

• Guhumeka nabi, cyane cyane mu gihe ukora imyitozo ngororamubiri
• Kubura imbaraga zidasanzwe ugereranije n'ibyo wakoraga
• Kubabara mu kifuba cyangwa kubabara mu gituza, cyane cyane mu gihe ukora imyitozo ngororamubiri
• Umuraba w'umutima cyangwa kumva umutima wawe uhagaze cyane
• Kuzenguruka cyangwa kumva ugiye kugwa, cyane cyane iyo uhagurutse vuba

Mu gihe ikibazo gikomeye, ushobora kugwa mu gihe ukora imyitozo ngororamubiri. Bamwe nabo babona kubyimba mu maguru, mu birenge, cyangwa mu birenge kuko umutima wabo uhangana no gutuma amaraso agenda neza mu mubiri wose.

Ni byiza kumenya ko ibimenyetso bishobora kuza buhoro buhoro mu myaka myinshi, bityo ushobora kutahuza na cyo vuba ko ari ikibazo cy'umutima. Niba ufite kimwe muri ibi bimenyetso, cyane cyane mu gihe ukora imyitozo ngororamubiri, ni byiza kuvugana n'abaganga.

Ubwoko bwa Pulmonary Valve Stenosis ni ubuhe?

Pulmonary valve stenosis igabanywamo ubwoko butandukanye hashingiwe aho bugabana buri, n'uburemere bw'imbogamizi. Gusobanukirwa ubwoko butandukanye bufasha muganga wawe gusuzuma uburyo bwiza bwo kuvura ukurikije uko uhagaze.

Hashingiwe aho biherereye, hari ubwoko butatu nyamukuru:

• Valvular stenosis: Ubwoko busanzwe, aho ibice by'umusemburo biba byarakomeye, byahujwe, cyangwa byahindutse
• Subvalvular stenosis: Bugabana buri munsi y'umusemburo, akenshi bitewe n'imikaya y'inyongera cyangwa imigozi
• Supravalvular stenosis: Bugabana buri hejuru y'umusemburo mu muyoboro w'amaraso ujya mu mwijima

Abaganga kandi bagabanya iki kibazo ukurikije ubukana bwacyo. Stenosis yoroheje ntabwo ikora ku bimenyetso kandi ishobora kudakenera kuvurwa. Stenosis yo hagati ishobora gutera ibimenyetso mu gihe cy'imyitozo ngororamubiri ikomeye, mu gihe stenosis ikomeye ishobora kugira ingaruka ku buzima bwawe bwa buri munsi kandi ikaba ikenera kuvurwa.

Inkuru nziza ni uko, uko ubwoko bwaba ubwo ari bwo bwose, hari uburyo bwo kuvura bufasha gucunga ubuzima bwawe no kunoza imibereho yawe.

Impamvu za Pulmonary Valve Stenosis ni izihe?

Urugero rwinshi rwa pulmonary valve stenosis ni rwo rwavutse, bisobanura ko wavutse ufite icyo kibazo. Ibi bibaho iyo umusemburo wa pulmonary udatemba neza mu gihe cy'ibyumweru umunani bya mbere byo gutwita, nubwo tutazi impamvu ibyo bibaho.

Ibintu byinshi bishobora gutera pulmonary valve stenosis yavutse:

• Ibintu by'umuzuko, nubwo nta gene runaka rizwi neza mu bihe byinshi
• Indwara zimwe na zimwe z'umuzuko nka Noonan syndrome cyangwa Williams syndrome
• Indwara nyina yanduye mu gihe cyo gutwita, nka rubella
• Nyina gukoresha imiti imwe mu gihe cyo gutwita
• Nyina kunywa inzoga mu gihe cyo gutwita

Mu bihe bidasanzwe, pulmonary valve stenosis ishobora kuza mu myaka y'ubukure. Iyi ndwara ishobora guterwa n'indwara y'umutima ya rheumatic, imiti imwe n'imwe itera indwara y'umutima, cyangwa nk'ingaruka z'ibindi bibazo by'umutima.

Ni byiza gusobanukirwa ko niba ufite iyi ndwara, ntabwo ari ikintu wowe cyangwa ababyeyi bawe bakoze nabi. Ibibazo by'umutima byavutse bibaho mu gihe cy'iterambere risanzwe, kandi mu bihe byinshi, nta buryo bwo kubikumira.

Ni ryari ukwiye kujya kwa muganga kubera Pulmonary Valve Stenosis?

Ukwiye kujya kwa muganga niba ufite ibimenyetso bishobora kugaragaza ko umutima wawe ukora cyane uko bisanzwe. Ntugatege amatsiko ibimenyetso bikomeye, kuko kumenya hakiri kare no gukurikirana bishobora kugira uruhare mu buzima bwawe bw'igihe kirekire.

Shaka ubufasha bw'abaganga niba ubona guhumeka nabi mu gihe ukora ibintu byoroshye, kubura imbaraga zidasanzwe, cyangwa kubabara mu gituza mu gihe ukora imyitozo ngororamubiri. Ibi bimenyetso bishobora kuza buhoro buhoro, bityo witondere impinduka mu buryo ukora imyitozo ngororamubiri cyangwa mu mbaraga zawe.

Ubufasha bw'abaganga bugomba kuba bwihuse niba ugwa, ubona ububabare bukomeye mu gituza, cyangwa guhumeka nabi bikaba bikomeye. Ibi bishobora kugaragaza ko ubu burwayi bwakomeye kandi bukaba bukenera isuzuma ryihuse.

Niba ufite amateka y'ibibazo by'umutima byavutse mu muryango wawe, ni byiza kubivugana n'abaganga bawe nubwo udafite ibimenyetso. Rimwe na rimwe, isuzuma riyoroshye rishobora kumenya indwara nka pulmonary valve stenosis mbere y'uko ibimenyetso bigaragara.

Ibyago bya Pulmonary Valve Stenosis ni ibihe?

Kubera ko ibice byinshi bya pulmonary valve stenosis biba kuva umuntu akiri mu nda, ibyago byabyo bijyanye ahanini n'ibintu bibaho mu gihe cyo gutwita no mu iterambere ry'umwana. Gusobanukirwa ibyo bishobora gufasha imiryango gufata ibyemezo byiza, nubwo ari ngombwa kwibuka ko ibice byinshi bibaho nta kintu cyabiteye kizwi.

Ibyago nyamukuru birimo:

• Amateka y'ibibazo by'umutima byavutse mu muryango, nubwo isano y'umuzuko atari ihoraho
• Indwara zimwe na zimwe z'umuzuko zigira ingaruka ku iterambere ry'umutima
• Nyina yanduye mu gihe cy'amezi atatu ya mbere yo gutwita
• Indwara ya diyabete nyina adacunga neza mu gihe cyo gutwita
• Gukoresha imiti imwe mu gihe cyo gutwita, harimo imiti imwe ivura indwara zifata ubwonko
• Nyina kunywa inzoga cyangwa ibiyobyabwenge mu gihe cyo gutwita

Indwara zimwe na zimwe z'umuzuko nka Noonan syndrome, LEOPARD syndrome, cyangwa Williams syndrome zigira ibyago byinshi bya pulmonary valve stenosis. Niba ufite imwe muri izo ndwara, gukurikirana umutima buri gihe ni byo bisabwa.

Ku bijyanye na pulmonary valve stenosis yabonetse, ibyago birimo amateka ya rheumatic fever, indwara zimwe na zimwe zifata umubiri, cyangwa indwara zanduye umutima mbere. Ariko, izi mpamvu ni nke cyane ugereranije n'iyavutse.

Ingaruka zishoboka za Pulmonary Valve Stenosis ni izihe?

Nubwo pulmonary valve stenosis yoroheje idatera ingaruka, izikomeye zishobora gutera ibibazo niba zititaweho. Inkuru nziza ni uko, hakurikijwe gukurikirana no kuvura neza, ingaruka nyinshi zishobora kwirindwa cyangwa gucungwa neza.

Ingaruka zisanzwe zibaho iyo umutima wawe ukora cyane igihe kirekire:

• Umutima wo mu gice cy'iburyo ukura ukaba munini kandi ukaba ukomeye ukoresha imbaraga nyinshi kugira ngo utume amaraso anyura mu musemburo muto
• Ibibazo by'umutima, cyane cyane mu bice by'umutima byo hejuru
• Gucika intege kw'umutima, aho umutima wawe udashobora gutuma amaraso agenda neza mu mubiri wawe
• Kugabanuka kw'ubushobozi bwo gukora imyitozo ngororamubiri n'imibereho myiza
• Ibyago byiyongereye byo kwandura mu misemburo y'umutima (endocarditis)

Mu bihe bidasanzwe, bikomeye, urupfu rutunguranye rw'umutima rushobora kubaho, cyane cyane mu gihe cy'imyitozo ngororamubiri ikomeye. Niyo mpamvu ari ngombwa gukurikirana buri gihe n'umuganga w'umutima niba ufite stenosis yo hagati cyangwa ikomeye.

Mu gihe cyo gutwita, pulmonary valve stenosis ikomeye ishobora kugira ingaruka ku mubyeyi n'umwana. Ariko, hakurikijwe gukurikirana no kwitaho neza, abagore benshi bafite iyi ndwara bagira gutwita neza.

Igenamigambi ryo kwirinda ingaruka ni ugukorana n'itsinda ry'abaganga kugira ngo bakurikirane ubuzima bwawe kandi bagufashe igihe bibaye ngombwa. Abantu benshi bafite pulmonary valve stenosis bashobora kubaho ubuzima bwiza, buhamye, bafite ubufasha bukwiye.

Uko Pulmonary Valve Stenosis imenyekana

Kumenya pulmonary valve stenosis bisanzwe bitangira muganga wawe yumvise umutima wawe akoresheje stethoscope. Umusemburo muto akenshi utera ijwi ryihariye ryitwa heart murmur ryumvikana neza n'amatwi yatojwe.

Niba muganga wawe akekako ufite pulmonary valve stenosis, azakora ikizamini cyitwa echocardiogram. Iki kizamini kidakomeretsa gikoreshwa amajwi kugira ngo akore amashusho y'umutima wawe, agaragaza uko misemburo yawe ifunguka n'uko umutima wawe upompa amaraso.

Ibizamini byinyongera bishobora kuba birimo:

• Electrocardiogram (ECG) kugira ngo urebe ibikorwa by'amashanyarazi y'umutima wawe n'umuvuduko wacyo
• X-ray y'amabere kugira ngo urebe ingano n'isura y'umutima wawe n'imwijima
• Isuzuma ry'imyitozo ngororamubiri kugira ngo urebe uko umutima wawe ukorana n'imyitozo ngororamubiri
• Cardiac catheterization kugira ngo upime neza umuvuduko w'amaraso mu mutima wawe
• CT cyangwa MRI scan kugira ngo ubone amashusho arambuye y'umutima wawe

Uburyo bwo gusuzuma busanzwe buroroshye kandi ntabwo bukomeretsa. Muganga wawe azakoresha ibi bizamini kugira ngo amenye niba ufite pulmonary valve stenosis, ubukana bwayo, niba ukeneye kuvurwa.

Rimwe na rimwe iyi ndwara iboneka mu isuzuma rusanzwe cyangwa mu bizamini by'izindi ndwara. Ibi ni inkuru nziza, kuko kumenya hakiri kare bituma habaho gukurikirana neza no kuvura igihe bibaye ngombwa.

Uko Pulmonary Valve Stenosis ivurwa

Uburyo bwo kuvura pulmonary valve stenosis biterwa n'uburemere bw'uburwayi bwawe niba ufite ibimenyetso. Abantu benshi bafite stenosis yoroheje bakenera gukurikiranwa gusa, abandi bashobora kugira inyungu mu buryo bwo gufungura umusemburo muto.

Ku bijyanye n'ibibazo byoroheje bidatera ibimenyetso, muganga wawe azakugira inama yo gukurikirana buri gihe kugira ngo akurikirane uburwayi. Ubu buryo, bwitwa gutegereza, bukuberaho kubaho ubuzima busanzwe mugihe ubuhinduke bwose bufatwa hakiri kare.

Iyo kuvura bibaye ngombwa, uburyo nyamukuru burimo:

• Balloon valvuloplasty: Uburyo buto bwo kuvura aho umupira muto ufungurwa mu musemburo kugira ngo uwugurure
• Kuvura umusemburo: Kubaga umutima kugira ngo uhindure cyangwa wongere umusemburo
• Gusimbuza umusemburo: Gusimbuza umusemburo wangiritse n'undi mushya, uba ari uw'imashini cyangwa uw'umubiri
• Imiti: Gucunga ibimenyetso nka bibazo by'umutima cyangwa kubyimba

Balloon valvuloplasty niyo nzira ya mbere ku barwayi benshi kuko ntabwo ari ubuvuzi bukomeye. Iki gikorwa gikorerwa mu muyoboro muto winjizwa mu muyoboro w'amaraso, akenshi mu kuguru, ukajyanwa mu mutima.

Umuganga w'umutima azakorana nawe kugira ngo asuzume uburyo bwiza bwo kuvura ukurikije uko uhagaze, imyaka yawe, ubuzima bwawe muri rusange, n'ibyo ukunda. Intego ni ugukomeza kugufasha kugira imibereho myiza.

Uko wita ku buzima bwawe iwawe ufite Pulmonary Valve Stenosis

Kwita ku buzima bwawe iwawe ufite pulmonary valve stenosis bigamije gushyigikira ubuzima bwawe bw'umutima muri rusange no kumenya igihe ukeneye ubufasha bw'abaganga. Ubufasha bw'umwihariko ukeneye biterwa n'uburemere bw'uburwayi bwawe n'ibyo muganga wawe akugira inama.

Ku bijyanye n'ibibazo byoroheje, ushobora gukomeza ibikorwa byawe bisanzwe ufite ingamba zimwe na zimwe. Komereza gukora imyitozo ngororamubiri ukurikije uko wumva, ariko witondere uko wumva mu gihe ukora imyitozo ngororamubiri. Niba ubona guhumeka nabi, kubabara mu gituza, cyangwa kuzenguruka, ni igihe cyo kugabanya umuvuduko no kuruhuka.

Ingamba z'ingenzi zo kwita ku buzima iwawe zirimo:

• Gukoresha imiti yose yatanzwe na muganga wawe ukurikije amabwiriza
• Gukurikirana ibimenyetso byawe no kwandika impinduka zose
• Kwita ku buzima bw'amenyo kugira ngo wirinde kwandura bishobora kugira ingaruka ku mutima wawe
• Kurya indyo iboneye umutima ufite umunyu muke niba ari byo byagiriwe inama
• Kuryama bihagije no gucunga umunaniro
• Kwirinda itabi no kugabanya kunywa inzoga

Niba ufite stenosis yo hagati cyangwa ikomeye, muganga wawe ashobora kugira inama yo kwirinda ibikorwa bimwe na bimwe bikomeye cyangwa imikino y'amarushanwa. Ibi ntibisobanura ko udashobora gukora imyitozo ngororamubiri, ahubwo ko ukwiye guhitamo ibikorwa bidashyira umuvuduko ku mutima wawe.

Buri gihe menyesha abandi baganga, harimo abaganga b'amenyo n'abaganga babaga, ibibazo by'umutima wawe. Bashobora kuba bakeneye kwitondera ibintu bimwe na bimwe, nko kuguha imiti yo kwirinda kwandura mbere y'ibikorwa bimwe na bimwe kugira ngo wirinde kwandura mu mutima.

Uko wakwitegura gusura muganga

Kwita ku gusura muganga w'umutima bigufasha kubona ibyiza byinshi mu ruzinduko rwawe kandi muganga wawe agira amakuru yose akenewe kugira ngo aguhe ubufasha bwiza. Gutegura gato bishobora kugira uruhare mu mibereho myiza y'ibiganiro byawe.

Mbere yo gusura muganga, andika ibimenyetso byawe byose, nubwo byaba bito. Bandika igihe bibaho, icyabiteye, n'igihe biba. Aya makuru afasha muganga wawe gusobanukirwa uko uburwayi bwawe bugira ingaruka ku buzima bwawe bwa buri munsi.

Zana ibi mu ruzinduko rwawe:

• Urutonde rwuzuye rw'imiti yose, ibintu byongera imbaraga, na vitamine ufata
• Amakuru y'ubwisungane bwawe n'amafishi yose ukeneye
• Ibisubizo by'ibizamini byabanje, cyane cyane ibizamini by'umutima nka ECGs cyangwa echocardiograms
• Urutonde rw'ibibazo ushaka kubabaza muganga wawe
• Amakuru ku mateka y'ubuzima bw'umutima mu muryango wawe

Tegura ibibazo byihariye ku bijyanye n'uburwayi bwawe, uburyo bwo kuvura, n'icyo witeze. Ntugatinye kubabaza ibibazo ku bijyanye n'ibikorwa, igihe cyo gushaka ubufasha bw'ibikorwa byihuse, cyangwa ukuntu uzasura muganga.

Tekereza kuzana inshuti cyangwa umuryango wawe kugira ngo aguhe inkunga mu kwibuka amakuru yavuzwe mu gihe cy'uruzinduko. Bashobora kandi kugufasha mu gutanga inkunga yo mu mutima no guharanira ubufasha bwawe niba bibaye ngombwa.

Icyingenzi cyo kumenya kuri Pulmonary Valve Stenosis

Ikintu cy'ingenzi cyo kumenya kuri pulmonary valve stenosis ni uko ari uburwayi bushobora kuvurwa kandi hari uburyo bwiza bwo kuvura buhari muri iki gihe. Nubwo byumvikana bibi kumenya ko ufite ikibazo cy'umusemburo w'umutima, abantu benshi bafite iyi ndwara babaho ubuzima busanzwe, buhamye.

Igenamigambi ry'intsinzi ni ugukorana n'itsinda ry'abaganga kugira ngo bakurikirane ubuzima bwawe kandi bakurikize amabwiriza yabo. Nubwo udafite ibimenyetso ubu, kugumana umubano n'umuganga w'umutima bizatuma impinduka zose mu buzima bwawe zifatwa hakiri kare igihe kuvura ari byo bikenewe.

Ubuvuzi bwa none butanga ibisubizo bitangaje kuri pulmonary valve stenosis, kuva mu buryo buto bwo kuvura kugeza ku buryo bugezweho bwo kubaga. Abantu benshi bakeneye kuvurwa bagira iterambere rikomeye mu bimenyetso byabo no mu mibereho myiza.

Wibuke ko kugira iyi ndwara bidakugaragaza cyangwa kudakubuza ibyo ushobora kugeraho mu buzima. Ufite ubufasha bukwiye, ushobora gukurikira intego zawe, kugumana umubano, no kwishimira ibikorwa bikubereye. Ibibazo by'umutima wawe ni kimwe mu bintu by'ubuzima bwawe bishobora gucungwa neza.

Ibibazo Bikunze Kubahwa kuri Pulmonary Valve Stenosis

Nshobora gukora imyitozo ngororamubiri niba mfite pulmonary valve stenosis?

Abantu benshi bafite pulmonary valve stenosis yoroheje bashobora gukora imyitozo ngororamubiri bisanzwe kandi bagomba gukora imyitozo ngororamubiri kugira ngo ubuzima bwabo bw'umutima bube bwiza. Ariko, niba ufite stenosis yo hagati cyangwa ikomeye, muganga wawe ashobora kugira inama yo kwirinda ibikorwa bikomeye cyangwa imikino y'amarushanwa byongera umuvuduko w'umutima wawe n'umuvuduko w'amaraso.

Icyingenzi ni ukumva umubiri wawe no gukorana n'umuganga w'umutima kugira ngo umenye icyakubereye. Abantu benshi basanga ibikorwa nko kugenda, koga, cyangwa kugendera kuri velo umuvuduko utari mwinshi bikora neza, abandi bashobora kuba bakeneye kwirinda imikino ikomeye.

Nzakenera kubagwa kubera pulmonary valve stenosis?

Kubagwa ntibikenewe kuri buri wese ufite pulmonary valve stenosis. Abantu benshi bafite ibibazo byoroheje ntibakenera kuvurwa uretse gukurikiranwa gusa. Ku bantu bakeneye kuvurwa, balloon valvuloplasty niyo nzira ya mbere kuko ntabwo ari ubuvuzi bukomeye.

Muganga wawe azakugira inama yo kubagwa gusa niba inyungu zirusha ibyago ku bijyanye n'uko uhagaze. Ibintu nka myaka yawe, ubuzima bwawe muri rusange, ubukana bw'ibimenyetso, n'uko umutima wawe ukora bigira uruhare muri icyo cyemezo.

Pulmonary valve stenosis ishobora kuba mbi uko igihe gihita?

Pulmonary valve stenosis ishobora kuba mbi uko igihe gihita, cyane cyane mu gihe umusemburo ukomeza gukomera cyangwa gucika. Ariko, abantu benshi bafite stenosis yoroheje idahinduka cyane mu buzima bwabo.

Niyo mpamvu gukurikirana buri gihe n'umuganga w'umutima ari ingenzi. Muganga wawe azakurikirana impinduka zose kandi agufashe niba uburwayi bwakomeye ku buryo kuvura bibaye ngombwa.

Pulmonary valve stenosis irazimukira?

Nubwo pulmonary valve stenosis ishobora kuba mu muryango, ntirazimukira nk'izindi ndwara z'umuzuko. Niba ufite iyi ndwara, abana bawe bafite ibyago bike kurusha abandi, ariko abana benshi bafite ababyeyi barwaye bavuka bafite imitima isanzwe.

Niba uteganya kubyara, bivugane n'umuganga w'umutima n'umuganga wita ku gutwita. Bashobora kugira inama yo gukurikirana gutwita kugira ngo barebe iterambere ry'umutima w'umwana wawe, nubwo ibi ari ugukora ibishoboka.

Ni iki kibaho niba pulmonary valve stenosis ititiweho?

Ibyavuye mu kutavuza pulmonary valve stenosis biterwa n'uburemere bwacyo. Ibibazo byoroheje bikunze kuguma bisanzwe mu buzima kandi ntibitera ibibazo. Ariko, ibibazo byo hagati cyangwa bikomeye bidavuwe bishobora gutera umutima gukura, ibibazo by'umutima, kandi amaherezo gucika intege kw'umutima.

Inkuru nziza ni uko, ubuvuzi bwa none bufasha gukurikirana no gusuzuma, pulmonary valve stenosis ikomeye idavuwe ibaye nke cyane. Ibice byinshi bimenyekana kandi bikurikiranwa neza, kuvurwa bigatangwa igihe bibaye ngombwa kugira ngo birinde ingaruka.