--- In ekg_club@yahoogroups.com, Nikiah Nudell <medicnick@...> wrote:
>
> Hi Jesse,
> I just wanted to clarify something you mentioned. Pwaves may be present in
> PVCs or PACS. One has to be careful to determine whether the Pwave is
> 'associated' with the QRS complex.
>
> Some rythms can be tricky to differentiate in a 12 lead. If it is bigeminy
> with a bundle branch block, for example, it can be nearly impossible to
> determine from a single 12lead which is the ectopy and which is the
> underlying rhythm.
>
> Cheers,
> Nick
>
> On Sun, Jul 5, 2009 at 11:12, jesse12848 <jesse12848@...> wrote:
>
> >
> >
> > --- In ekg_club@yahoogroups.com <ekg_club%40yahoogroups.com>,
> > "thatsuthant" <thatsuthant@> wrote:
> > >
> > > Hi every one,
> > > How do you differentiate atrial ectopic beats from ventricular ectopic
> > beats?. Any one can define me please?.
> > > Ventricular ectopic beats are clearly seen on ECG . But atrial ectopic
> > beats, how you all find those?. Please give some of your thoughts.
> > >
> > > Thanks
> > >
> > >
> > >
> > > --- In ekg_club@yahoogroups.com <ekg_club%40yahoogroups.com>, Klaus
> > Skrudland <lapsklaus@> wrote:
> > > >
> > > > Hi all. Just want to present to you a case of what I believe is a quite
> > > > uncommon ectopic rhythm.
> > > >
> > > > The patient is a 55 y/o male with a well known paroxysmal atrial
> > > > fibrillation. He uses flecainide and metoprolol and was admitted for
> > onset
> > > > of what he thought was atrial fibrillation.
> > > >
> > > > As you will see from the ecg, the ventricular rate is irregular. Right
> > > > precordial leads show ectopic, positive P waves. PP intervals are
> > regular
> > > > with a rate of 230 bpm. When marching them out with a caliper (see the
> > dots
> > > > I made), they seem to march right through the QRS complexes and don´t
> > seem
> > > > to get conducted. However, there can´t be AV dissociation, as there is
> > no
> > > > evidence of an escape pacemaker present (and the ventricular rate is
> > > > irregular).
> > > >
> > > > As a matter of fact, the P waves does seem to get conducted after all.
> > My
> > > > colleague Terje (the other Norwegian here in the club) pointed out that
> > the
> > > > PR interval in fact gets progressively longer. And at this point, I´m
> > > > struggling to understand the rest of the mechanism. Most likely, this
> > atrial
> > > > tachycardia with some kind of Wenkebach conduction.
> > > >
> > > > Comments? Thoughts? Ideas? Anyone wanna make a ladderdiagram to explain
> > the
> > > > mechanism?! ;-)
> > > >
> > > > klaus
> > > >
> > >
> > In the caes of a true atrial ectopic beat, the QRS will be preceded by a
> > definite, upright P wave. P wave morphology may fulctuate (wandering
> > pacemaker, etc.), but if the premature beat is truely atrial in origin then
> > a P wave will be present. Another way to distinguish PACs from PVCs is to
> > view them in leads I and III. Also remember that PACs have a QRS duration
> > time of < 0.12 sec, whereas PVCs almost always have duration times > 0.12
> > sec.
> > If your sure that it's a PVC your looking at, you can determine L or R
> > origin by viewing it in MCL1/v1. L vent PVCs will be positive in deflection
> > while R vent PVCs will be aberrant. Hope this helps.
> >
> >
> >
>
Nick, right on. Thats a great catch. It is important to determine wether the P
wave is in fact associated with the QRS. Thanks for the correction.