guayoman
Forum Elite
Topics: 44
Posts: 273
|
Why is Afib caused by LEFT atrial enlargement? If the conduction system is in the RIGHT atrium?
___________________
Confidence does not come from simply reading the content, but from doing things with it. Confidence is born in the flash of insight, in the ability to face something new and figure it out.
Kaplan usmle edge newsletter
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
Hypertension is an important treatment target for prevention of atrial fibrillation. Hypertension may trigger hypertrophy, not only of the left ventricle but also of the left atrium. The latter predisposes to atrial fibrillation but also to thrombosis and systemic embolism from the left atrium.
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
Atrial fibrillation is multi-foci of automatous sites.
The atrial enlargement stretches the muscles of the left atrium and distorts the sinus node function indirectly. The atrium are just very thin muscle and by stretching 25% will cause the sinus node not function properly and may trigger multi-foci beating areas
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
In conclusion, it has been proved that AF occurring in patients with hypertensive heart disease causes a slow and progressive increase in LA size especially in patients in functional III NYHA class, and that the maintenance of sinus rhythm partially reverts the process of LA enlargement in patients with well-controlled hypertension, a history of AF and successfully treated for AF.
PMID: 15860382 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
Display Summary Brief Abstract Citation MEDLINE XML UI List LinkOut ASN.1 Related Articles Cited Articles Cited in Books CancerChrom Links Domain Links 3D Domain Links GEO DataSet Links Gene Links Gene (GeneRIF) Links Genome Links Project Links GENSAT Links GEO Profile Links HomoloGene Links Nucleotide Links OMIA Links OMIM (calculated) Links OMIM (cited) Links BioAssay Links Compound Links Compound via MeSH Substance Links Substance via MeSH PMC Links Cited in PMC PopSet Links Probe Links Protein Links SNP Links Structure Links UniGene Links UniSTS Links Show 5 10 20 50 100 200 500 Sort by Pub Date First Author Last Author Journal Send to Text File Printer Clipboard E-mail Order
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
What is atrial fibrillation?
Atrial fibrillation is a heart rhythm disturbance. It causes an irregular and sometimes very fast heartbeat.
How does it occur?
An electrical impulse within your heart causes it to pump. Normally, this impulse starts in the right upper chamber of the heart (the right atrium). It then moves along a pathway to the lower chambers of the heart (the ventricles).
In atrial fibrillation, the upper part of your heart beats faster than the rest of your heart. The atrial muscles quiver. The electrical impulses do not all reach the lower chambers of the heart. This makes the heart beat irregularly. This irregularity can affect the ability of the heart to pump enough blood to your brain and other organs. It can also make the heart beat very fast.
Common causes of atrial fibrillation are:
heart disease, including coronary artery disease, heart enlargement due to many years of high blood pressure, and heart failure from other causes
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
I think it is longstanding hypertension that causes both atrial enlargement and atrial fibrillation.
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| karusmle
Forum Guru
Topics: 296
Posts: 1,001
|
do they ask these kinda questions???
|
| guayoman
Forum Elite
Topics: 44
Posts: 273
|
Nope! That was me asking. I had a q wrong on a Q bank and I wondered why it was left and not right atrial dilation.
___________________
Confidence does not come from simply reading the content, but from doing things with it. Confidence is born in the flash of insight, in the ability to face something new and figure it out.
Kaplan usmle edge newsletter
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
It is left atrial enlargement because the left ventricles have to pump blood against a much higher pressure outflow in the aorta caused by hypertension.
The right atrium faces almosts no pressure because the right ventricle pumps blood against the pulmonary arteries which is 10-15 mmHg vs 160-190 mmHg in the aorta !
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
Wrong ! They ask these kind of questions and you sure need to know this in the ward !
How are you going to head to head with American best medical students !
Common On !
You need to know the left atrial enlargement reaches a critical size when the diameter reaches 5.5 cm !
Don't fool yourself ! You need to know everything in medicine !
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| AAAAA
Forum Fanatic
Topics: 156
Posts: 1,991
|
Left atrial volume is a more robust marker of cardiovascular events than LA area or diameter in subjects with sinus rhythm. The predictive utility of LA size for cardiovascular events in AF was poor, irrespective of the method of LA size quantitation
___________________
seeking study partner in USMLE, Canadian MCC OSCE examination
|
| guayoman
Forum Elite
Topics: 44
Posts: 273
|
Thanks AAAAA!
___________________
Confidence does not come from simply reading the content, but from doing things with it. Confidence is born in the flash of insight, in the ability to face something new and figure it out.
Kaplan usmle edge newsletter
|
|
| |
| | | | | | | | | | | | |
Similar forum topics