Ecg in aflutter

ECG IN ATRIAL FLUTTER

1. ECG FEATURES OF ATRIAL FLUTTER

2. Atrial flutter is characterized by a rapid, regular atrial rhythm at a rate of 250 to 350 beats/min . There are usually no isoelectric segments between the regular, uniformly shaped, biphasic, sawtooth -like oscillations . Most commonly the ventricular response in the absence of treatment is 2:1 but may be 4:1, 3:1, 3:2, or any other manifestation of atrioventricular (AV) block .

3. Type I, or typical, atrial flutter macroreentrant atrial tachycardia. type I flutter requires the isthmus of tissue between the inferior vena cava (IVC) and tricuspid annulus as a necessary component, it is often referred to as "isthmus-dependent" flutter. common form (=90%) of isthmus-dependent flutter, the reentrant circuit rotates around the tricuspid annulus in a counterclockwise direction . Less often(10%), the reentrant circuit rotates in the opposite direction, type I, typical, isthmus-dependent flutter, "reverse", or "clockwise" flutter .

4. Type II, or atypical , atrial flutter was considered unclassified because the mechanisms are not fully understood. any tachycardia fulfilling the classic ECG definition of a continuously undulating pattern but not fitting the typical flutter patterns (counterclockwise or clockwise) . The main distinguishing characteristics were an atrial rate greater than 340 or 350 beats/min the inability to be entrained .

5. Scheinman et al classification CAVO-TRICUSPID ISTHMUS-DEPENDENT ATRIAL FLUTTER NONCAVOTRICUSPID-DEPENDENT ATRIAL FLUTTER

6. CCW Atrial Flutter Typical Most common type - 90% From a left anterior oblique (LAO) fluoroscopic view, the circuit rotates in a CCW direction

7. cranial caudal activation sequence along the right atrial lateral wal l, across the cavotricuspid isthmus in a lateral-to-medial direction superiorly in the right atrial septum

8. Clockwise (CW) Atrial Flutter Reversed version of CCW AFL 10% same boundaries as its counterclockwise counterpart

9. ELECTROCARDIOGRAM IN TYPE I ATRIAL FLUTTER   P waves are absent . Biphasic " sawtooth " flutter waves (F waves) are present at a rate of about 300 beats/min , with the range for type I being 250 to 350 beats/min; in comparison, the flutter rate is 340 to 440 beats/min in type II flutter . The F waves usually do not have an isoelectric interval between them, unless the rate of the atrial flutter is slow. F waves have the appearance of a down sloping segment followed by a sharp negative deflection, a sharp positive deflection that may have a positive overshoot leading into the next downward deflection .

10. Counter-clockwise flutter Lead V1 - initial isoelectric component followed by an upright component. With progression across the precordium, the initial component rapidly becomes inverted and the second component isoelectric usually by V2 to V3 this produces the overall impression of an upright flutter wave in V1 which becomes inverted by V6. Lead I is low amplitude/isoelectric aVL usually upright .

11. clockwise flutter inferior leads- flutter waves are usually broadly positive, with characteristic notching .  However, there is an inverted component preceding the upright notched component. Depending on the amplitude of this component, the appearance can be of continuous undulation without an obviously predominant upright or inverted component On other occasions, it may appear that the inverted component is dominant, thus superficially mimicking counterclockwise flutter.   V1 -broad negative and usually notched deflection transition across the precordium to an upright deflection in V6.   Lead I -upright aVL - low amplitude negative and notched

12. Atrial flutter with 2:1 block:

13. The ventricular response (R-R intervals) is usually one-half the rate of the atrial input ( ie , 2:1 AV nodal conduction with a ventricular response of about 150 beats/min). AV block greater than 2:1 in the absence of drugs that slow the ventricular response suggests AV nodal disease which, in turn, may be part of the sick sinus or tachy-brady syndrome. 1:1 AV response suggests accessory bypass tracts, sympathetic excess, and parasympathetic withdrawal Even ratios of input to output ( eg , 2:1, 4:1) are much more common than odd numbers ( eg , 3:1, 5:1). Odd ratios and shifting ratios ( eg , alteration of 2:1 with 4:1) probably reflect bilevel block in the AV node. The QRS complex is narrow unless there is functional aberration, preexisting bundle branch or fascicular block, or preexcitation .

14. The general rule is the shallow stroke (one with a lesser slope) is to be termed  as antegrade  / initial deflection that will determine the direction of flutter waves . In lead the polarity of F waves in V1 it will be opposite of that of inferior leads.

15. aVF /lead I flutter wave amplitude ratio was > 2.5 in all counterclockwise but < 2.5 in all clockwise atrial flutters . The flutter wave nadirs in the inferior leads corresponded to the upstrokes in V1 in all counterclockwise atrial flutters, but corresponded to the downstrokes in V1 in all clockwise atrial flutters .

16. typical atrial flutter (AFL) negative flutter waves in leads II, III, and aVF positive flutter waves in lead V1 reverse typical AFL positive flutter waves in inferior leads negative flutter waves in lead V1

17. ECG features of type II AFL P waves are absent. Biphasic flutter waves (F waves) are present at a rate of 340 to 440 beats/min. The F waves usually do not have an isoelectric interval between them. There often is more apparent positivity in the F waves recorded in the inferior leads. The F waves are regular and have a rather constant amplitude, duration, morphology, and reproducibility throughout the cardiac cycles. This uniformity distinguishes type II atrial flutter from coarse atrial fibrillation.

18. Right atrial flutter Circuits due to anatomic obstacles that exist remote from the CTI. Right atrial scars due to surgical repair of congenital heart defects serve as anatomic obstacles for macro-reentry. Scars in the posterolateral and inferolateral right atrium have been found to be involved in flutter circuits. The ECG appearance of free wall AFL is highly variable Hallmark for a right atrial free wall flutter– inverted flutter wave in V1 . Depending on the predominant direction of septal activation, right atrial free wall flutter can mimic either clockwise or counterclockwise flutter

19. Left atrial flutter less common Association with SHD including hypertension, mitral valve disease, left atrial dilation, and cardiac failure. Circuits occur around regions of spontaneous scarring frequently located in the posterior LA. Circuits may propagate around the mitral valve annulus, around regions of scarring, and the ostia of the pulmonary veins or infrequently may involve the septum rotating around the fossa ovalis . Surface ECG findings are variable, though the flutter wave amplitude tends to be low.

20. Left atrial flutter The flutter wave usually shows a prominent positive deflection in lead V1 and uncommonly is flat or isoelectric . The flutter waves in leads II, III, and aVF may be upright but are frequently of low amplitude Owing to a high prevalence of generalized atrial disease and slower conduction, longer cycle lengths with a greater isoelectric interval between flutter waves have been observed. Mimic a focal atrial tachycardia

21. right-sided vs. left-sided A broad-based upright V1 is highly predictive of a left-sided AFL. V1 is deeply inverted, this is highly suggestive of a right-sided flutter. V1 has an initial isoelectric (or inverted) component (followed by an upright component), this is consistent with a right AFL. V1 is biphasic or isoelectric , it is not helpful in predicting the chamber of origin.

22. Atrial flutter should be considered in all regular narrow complex tachycardia with a ventricular rate of ~150 bpm. Vagal manoeuvres may help differentiate  sinus tachycardia  from atrial flutter. In atrial flutter vagal manoeuvres may be ineffective or result in a rapid decrease in rate allowing flutter waves to be more easily seen . In atrial flutter with variable block the R-R distances will be multiples of each other unlike atrial fibrillation in which no relationship exists e.g. assuming atrial rate of 300bpm the R-R distance in 2:1 block is 400ms, in 3:1 block 600ms, in 4:1 block 800ms.

23. NARROW QRS TACHYCARDIA RESPONSE slowing of SA nodal activity can cause a temporary decrease in the atrial rate (in patients with sinus tachycardia). slowing of AV nodal conduction can lead to AV nodal block, which may " unmask" atrial electrical activity ( ie , reveal P waves or flutter waves ) by decreasing the number of QRS complexes that obscure the electrical baseline. Carotid sinus massage

24. NARROW QRS TACHYCARDIA some narrow QRS complex tachycardias that require AV nodal conduction (especially AVNRT and AVRT)= the transient slowing of AV nodal conduction can terminate the arrhythmia by interrupting the reentry circuit. Less commonly, CSM can cause some atrial tachycardias to slow and terminate. In some cases, no response i s obtained . Carotid sinus massage

25. Carotid sinus massage NARROW QRS TACHYCARDIA

26. NARROW QRS TACHYCARDIA

27. NARROW QRS TACHYCARDIA   Termination of the arrhythmia Termination with a P wave after the last QRS complex is most common in AVRT or AVNRT and is rarely seen with AT. Termination with a QRS complex can be seen with AVRT, AVNRT, or AT . If the tachycardia continues despite successful induction of at least some degree of AV nodal blockade, the rhythm is almost certainly AT or atrial flutter ; AVRT is excluded and AVNRT is very unlikely Carotid sinus massage

28. NARROW QRS TACHYCARDIA

29. A FLUTTER vs Focal atrial tachycardias classically exhibit alterations in cycle length with speeding (‘warm up’) and slowing (‘cool down’) at the onset and termination of tachycardia. The tachycardia cycle length is less helpful in differentiating between focal and macro-re-entrant mechanisms. Although the cycle length is usually ≥250 ms in focal atrial tachycardia, shorter cycle lengths are now well described. In this situation, particularly in the presence of intra-atrial conduction delay, there may be no observable isoelectric interval between P-waves, and an undulating baseline resembling AFL may be seen. conversely , macro-re-entrant circuits may have long cycle length in the presence of SHD and anti-arrhythmic agents.  2  Furthermore, in the presence of significant atrial scarring, there may be a long isoelectric interval between flutter waves, incorrectly suggesting a focal mechanism

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