词条 | Sinus rhythm |
释义 |
A sinus rhythm is any cardiac rhythm in which depolarization of the cardiac muscle begins at the sinus node.[1] It is characterised by the presence of correctly oriented P waves on the electrocardiogram (ECG).[2] Sinus rhythm is necessary, but not sufficient, for normal electrical activity within the heart.[2] The term normal sinus rhythm (NSR) is sometimes used to denote a specific type of sinus rhythm where all other measurements on the ECG also fall within designated normal limits, giving rise to the characteristic appearance of the ECG when the electrical conduction system of the heart is functioning normally.[2] However, other sinus rhythms can be entirely normal in particular patient groups and clinical contexts, so the term is sometimes considered a misnomer and its use is sometimes discouraged.[3] Other types of sinus rhythm which can be normal include sinus tachycardia, sinus bradycardia and sinus arrhythmia. Sinus rhythms may be present together with various other cardiac arrhythmias on the same ECG. CharacteristicsFor an ECG to be described as showing a sinus rhythm, the shape of the P wave in each of the 12 standard ECG leads should be consistent with a "typical P vector" of +50° to +80°.[4] This means that the P wave should be:
If the P waves do not meet these criteria, they must be originating from an abnormal site elsewhere in the atria and not from the sinus node; the ECG cannot therefore be classed as showing a sinus rhythm.[4] In general, each P wave in a sinus rhythm is followed by a QRS complex, and the sinus rhythm therefore gives rise to the whole heart's depolarisation. Exceptions to this include complete heart block and certain ventricular artificial pacemaker rhythms, where the P waves may be completely normal in shape, but ventricular depolarisation bears no relation to them; in these cases, the speed of the "sinus rhythm of the atria" and the speed of the ventricular rhythm must be calculated separately.[4] Characteristics of normal sinus rhythmBy convention, the term "normal sinus rhythm" is taken to imply that not only are the P waves (reflecting activity of the sinus node itself) normal in morphology, but that all other ECG measurements are also normal.[2][5] Criteria therefore include:
References1. ^{{cite book |last=Hampton |first=John R |date=2013 |title=The ECG Made Easy |location=Edinburgh |publisher= Churchill Livingstone|page=4 |isbn=9780702046421|edition=8th}} 2. ^1 2 {{cite book |last=Conover|first=Boudreau Conover |date=2003 |title=Understanding Electrocardiography |location=St Louis|publisher= Mosby|page=46 |isbn=9780323019057|edition=8th}} 3. ^{{cite book |last=Geiter|first=Henry B. |date=2006 |title=E–Z ECG Rhythm Interpretation |location=Philadelphia|publisher= F.A. Davis|page=106 |isbn=9780803620353|edition=1st}} 4. ^1 2 3 4 5 {{cite book |last1=Gertsch |first1=Marc |year=2004 |chapter=3. The Normal ECG and its (Normal) Variants |title=The ECG: A Two-Step Approach to Diagnosis |publisher= Springer-Verlag Berlin Heidelberg |pages=19–21 |edition=1 |doi=10.1007/978-3-662-10315-9 |doi-broken-date= |isbn=978-3-540-00869-9 |oclc=942900796 }} 5. ^{{cite journal|pmc=4685281 | pmid=26702344 | doi=10.15171/jcvtr.2015.33 | volume=7 | title=Evaluation of the P Wave Axis in Patients With Systemic Lupus Erythematosus | journal=J Cardiovasc Thorac Res | pages=154–57 | last1 = Acar | first1 = RD | last2 = Bulut | first2 = M | last3 = Acar | first3 = Ş | last4 = Izci | first4 = S | last5 = Fidan | first5 = S | last6 = Yesin | first6 = M | last7 = Efe | first7 = SC}} External links
1 : Cardiology |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。