MINIMASTER DI ELETTROCARDIOGRAFIA

L’ECG NELLE TACHICARDIE SOPRAVENTRICOLARI

UN CASO DI FLUTTER ATRIALE

DISCUSSANT : G. LEONE

Caso clinico

• G.T. uomo di anni 55• Affetto da pervietà interatriale tipo ostium secundum

corretta chirurgicamente nel 1987• Iperteso in trattamento con ibesartan• Ecocardio: ingrandimento biatriale modesto. Setto

Interatriale senza soluzione di continuità. Setto IV lievemente ipertrofico e discinetico. Normali le cavità ventricolari sx.

• Nel 1996 inizia a manifestare episodi ricorrenti di cardiopalmo per flutter atriale. Iniziato trattamento con antiaritmici : flecainide,propafenone, amiodarone.

• Nel 1997 ricovero per ablazione.

Ecg di base

Durante la procedura di ablazione si osserva :

Ciclo F-F di 250 msecOnde F negative in D2,D3,AVF, positive in V1

Come classificare questo flutter?

• Dall’esame del ciclo e della morfologia dell’onda F osserviamo:

• Ciclo F-F di 250 msec

• Onde F negative in D2,D3,AVF, positive in V1

TYPICAL ATRIAL FLUTTER

F Arribas, F. CosìoATRIAL FLUTTER ABLATION: role of endocardial mapping in J. Farrè-C. Moro: Ten years of RA, Futura 1998

Questo pattern a che cosa è ascrivibile?

• Flutter atriale tipico antiorario.

Typical atrial flutter

Typical atrial flutter: a macro-re-entry atrial regulartachycardia, either present at baseline or inducible byatrial stimulation, where the involvement of the inferiorvena cava — tricuspid annulus isthmus could be provenby concealed entrainment. The arrhythmia was definedas counterclockwise or clockwise in accordance with thedirection of the activation wavefront recorded on thetricuspid annulus catheter.

Durante la procedura di ablazione si osserva :

Ciclo F-F di 250 msecOnde F negative in D2,D3,AVF, positive in V1

Subito dopo, durante la procedura, si osserva :

Ciclo F-F 250 msecOnda F positiva in D1,D2,difasica in aVL,Isoelettrica in aVF, negativa in V1.

Il confronto ci fa apprezzare meglio le differenze:

Di cosa si tratta?

• Possiamo fare delle ipotesi:

Di cosa si tratta?

• Reverse typical atrial flutter

• Double loop intra-atrial

• Lower loop flutter

• Lesion macroreentrant tachycardia

• (Right atrial free wall macroreentry without atriotomy)

• Left atrial macroreentrant tachycardia

REVERSE TYPICAL ATRIAL FLUTTER

F Arribas, F. CosìoATRIAL FLUTTER ABLATION: role of endocardial mapping in J. Farrè-C. Moro: Ten years of RA, Futura 1998

Clinical and Echocardiographic Characteristics of Two

Types of CWID

Morphologic variations of clockwise isthmus-dependent atrial flutter on 12-lead surface electrocardiogram: (A) Type

1: F+(n) or F+ in II, III,aVF, and V6; F- in V1, narrow F-wave/distinct isoelectric

segment

(B) Type 2: f-/F+9(n) or F+(n) inferiorly and V6, isoelectric in V1, with a broad

F-wave and no distinct isoelectric segment.

LOWER LOOP FLUTTER

Zhang et al Clockwise Lower Loop Reentry

Circulation 2004;109;1630-1635;

Left atrial macroreentrant tachycardia

(Circulation 2004;109:2440-2447.)

– Il passaggio da una deflessione negativa nelle derivazioni inferiori a deflessioni positive indica che il cambio di polarità all’ecg è associato con una alterata attivazione settale che cambia da caudocraniale a craniocaudale e riflette probabilmente una simile modificazione nella attivazione dell’atrio sinistro.

This article describes the characteristics of dual-loop, figure-8 atrial reentry. All occurred in patients previously operated on for surgical closure of an ostium secundum atrial septal defect and required ablation of 2 isthmuses to be curative.

The simultaneous coexistence of both loops was proved by comprehensive 3D mapping and transformation to a single loop circuit with appropriately targeted RF application.

Transection of 1 loop (peritricuspid) allowed unopposed atrial activation by the other loop (periatriotomy) to be evident on the surface ECG.

This novel mechanism of transformation of a reentrant tachycardia ECG may also be considered the gold standard test for a true figure-8 reentry circuit in which the remaining loop is capable of independent stability as opposed to a figure-8 activation pattern.

Simultaneous periatriotomy loop activation is not

clearly evident on the surface ECG and that similarly posterior RA activation in typical flutter may not contribute to the surface ECG tracing.

The double-loop mechanism was revealed on ECG only by transection of 1 loop. The ECG transformation was instantaneous and without an intervening pause, which might suggest termination followed by induction.

• This is the first reported case of dual-loop intra-atrial re-entry tachycardia in a patientwith ischaemic cardiomyopathy.

• In our case, two tachycardia re-entry loops were connected (‘figure-of-eight’) such that one tachycardia could be transformed into the other tachycardia without pause or atrial extra-systole.

• This re-entry loop may possibly be related to scar tissue due to multiple prior coronary bypass procedures.

Shah et al.[5] described dual-loop intra-atrial re-entrytachycardia in a series of five patients. However, incontrast to our case, all of their patients had prior atrialseptal defect repair. Of interest all their patients hadcounter-clockwise TA/IVC isthmus dependent atrialflutter and a second loop related to an atriotomy/scartissue in the right atrial free wall. Similar to our case,ablation at two distinct sites was needed to cure thesetwo re-entry tachycardias.

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