![]() Multifocal atrial tachycardia – 3 or more p wave morphologies, irregular, usually seen with severe lung disease (COPD).Atrial tachycardia – different p-wave morphology than with sinus rhythm.P-waves identical to sinus p-waves, but rapid onset and termination helps distinguish from sinus tachycardia. SA nodal reentrant tachycardia - fairly rare, due to reentrant loop within the SA node.After cardioversion, patient should be anticoagulated for 4 weeksĭdx can also be broken down by site of origin:.In addition, even if no clot is present, there is a risk of embolism after cardioversion due to atrial stunning, which results in stasis within the LA.Thus, patients should be anticoagulated for 4 weeks prior to DCCV, or TEE performed to rule out LA clot (see attached NEJM paper).As in atrial fibrillation, flutter >48h carries a risk of post-cardioversion embolism (~1% risk).Pharmacologic: less effective, and agents carry some proarrhythmic risk.DCCV: requires conscious sedation, which may compromise hemodynamics.Restoration of NSR: improves hemodynamics, decreases oxygen demand, and alleviates symptoms.Thus, negative inotropy can drop CO and BP.In atrial flutter, preload is impaired due to shortened diastolic filling time.Remember that CO = HR x SV, and SV = contractility x preload.Digoxin: slow onset of action, and dependent on vagal tone for effect however, has positive inotropic effects.Amiodarone: has some negative inotropic effects, and can also cause unintended cardioversion.BB (metoprolol, esmolol): also negative inotropes.CCB (verapamil, diltiazem): negative inotropes, and cause peripheral vasodilation.In addition, AV node is less refractory than in atrial fibrillation, and thus high doses of AV nodal blocking agents can be required.Rate control: can be difficult, given that ventricular rate drops in fixed intervals (e.g.Electrically unstable, and often degenerates into atrial fibrillation or reverts to sinus rhythm.Pathophysiology: macroreentrant rhythm, typically involving tricuspid annulus.Dependent: arrhythmia terminates upon interruption of AV nodal conduction.Independent: arrhythmia persists despite interruption of AV nodal conduction.AV nodal dependence: whether or not AV node is part of reentrant circuit.Long: suggests atrial tachycardia or sinus tachycardia.Very short: suggests typical AVNRT, given rapid retrograde conduction.RP interval: distance from R wave to P wave (see attached Mayo Clin Proc review).Sinus P waves are positive in inferior leads, I, and aVL, negative/biphasic in V1, and negative in aVR.P wave morphology: all P waves are not sinus!. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |