Arash
Arya, M.D, Majid Haghjoo, M.D, Zahra Emkanjoo, M.D, Alireza Heydari, M.D.,
Mohammad Ali Sadr-Ameli, M.D.
Department of Pacemaker and Electrophysiology,
Rajaie Cardiovascular Medical Center, Mellat Park, Vali-Asr Avenue, Tehran
1996911151, Iran
Address for correspondence:
Arash Arya, M.D., Department of Pacemaker and Electrophysiology,
Rajaie Cardiovascular Medical Center, Mellat Park, vali Asr Avenue, Tehran
, Iran.
Email:
arya@rhc.ac.ir
Abstract
Observation
of Coincident arrhythmias is not uncommon but the co-existence of idiopathic
verapamil sensitive left ventricular tachycardia (ILVT) with other arrhythmias
is very rare. We hereby presented a 30 year old male patient with a history
of frequent episodes of palpitations and sustained narrow complex tachycardia.
During electrophysiologic study two arrhythmias, one with narrow complexes
which was shown to be typical atrioventricular nodal re-entrant tachycardia
and the other with wide QRS complexes and right bundle branch block and left
axis morphology, compatible with ILVT, were inducible. Radiofrequency catheter
ablation of both arrhythmias was done at two consecutive sessions. The patient
has remained asymptomatic without antiarrhythmic therapy for the past six
months.
Keywords: ventricular tachycardia, atrioventricular nodal
reentrant tachycardia, catheter ablation
Introduction
Idiopathic sustained
ventricular tachycardia (VT) accounts for 10-20% of patients with sustained
monomorphic VT
1. More than a half
of idiopathic VTs originates from right ventricle especially from the right
ventricular outflow tract (RVOT) and the remainder from the left ventricle
(LV). Idiopathic verapamil-sensitive LV tachycardia (ILVT) is the most common
type of idiopathic LV tachycardia
2.
Coincidence of RVOT tachycardia with atrioventricular nodal reentrant tachycardia
(AVNRT) has been described
3, but
coexistence of ILVT with other arrhythmias is much less common and rarely
reported
4. This case report describes
the coincidence of AVNRT and ILVT in a 30 year old patient.
Case Report
We hereby presented
a 30 year old male patient with three years history of frequent episodes
of palpitation. He had no structural heart disease. His previous medical records
revealed several ECGs during arrhythmia all showing regular narrow complex
tachycardia with a rate of 180beat/min. There was no documented wide complex
tachycardia. During initial EP study a narrow complex tachycardia was reproducibly
induced (
Figure 1-A) which was shown to be typical AVNRT (
Figure
2-A). Another regular arrhythmia with RBBB and left axis morphology (cycle
length=330 ms) and negative HV (-20 ms), compatible with ILVT was also induced
reproducibly by ventricular programmed electrical stimulation (
Figure
1-B and 2-B). RF catheter ablation of AVNRT was done successfully. After
ablation, the ILVT was still inducible. The patient received verapamil and
remained asymptomatic.
Figure 1: A, Twelve lead ECG of first arrhythmia
compatible with atrioventricular nodal re-entrant tachycardia. B,
Twelve lead ECG of second arrhythmia with RBBB and left axis morphology shown
to be idiopathic Verapamil sensitive left ventricular tachycardia.
Figure 2: A, Intracardiac electrograms and
selected surface electrograms during AVNRT. B, Intracardiac electrograms
and selected surface electrograms during ILVT. Black arrow shows His electrogram.
Note negative HV interval during tachycardia. White arrow shows purkinje
potential on left ventricle decapolar mapping catheter. Vertical dashed line
depicts the beginning of QRS complex on surface ECG. C, Signal on successful
site of ablation of ILVT. Black arrow shows the purkinje potential on ablation
catheter.
HRA: high right atrium, RVA: right ventricle apex,
CS: coronary sinus, LV: left ventricle mapping
catheter, Abl.: Ablation catheter.
As the ablation
procedure was prolonged the ablation of ILVT postponed to another session.
After one month the patient re-admitted for ablation of ILVT, three days
after discontinuation of verapamil. Three quadripolar catheters (6F, Josephson,
Bard Electrophysiology) were introduced via left femoral vein and positioned
at RV apex (and right ventricular outflow tract), His bundle and high right
atrium. A 7F steerable decapolar catheter (2-5-2 mm) was introduced via left
femoral artery (Marinr, Medtronic Inc, USA) and positioned in LV on interventricular
septum for recording intracardiac signals during sinus rhythm and tachycardia.
This catheter was used as a guide for localization of earliest purkinje
potential (PP) recording site by ablation catheter. A 7F ablation catheter
(Conductr, Medtronic Inc, USA) was introduced via right femoral artery and
positioned in LV on septum for mapping and subsequent RF ablation. The ILVT
was terminated by mechanical pressure at
earliest PP recording site
(
Figure 2-C). RF energy was applied (50 W, 70°C, 60 s) from distal
electrode of ablation catheter at this site during sinus rhythm. Repeated
programmed electrical stimulation before and after isoprotrenol infusion
(4µ/min) from atrium and ventricle failed to induce any arrhythmia.
The patient remained asymptomatic without antiarrhythmics during 6 months
of follow up.
Discussion
This case describes
the coincidence of AVNRT and ILVT. Occurrence of AVNRT in combination with
idiopathic VT has been previously described. In patients with RVOT tachycardia
the incidence of AVNRT has been reported to be as high as 15%
3. Our finding also shows the possibility of
such a combination in patients with ILVT. This underscores the importance
of searching for dual atrioventricular node physiology and inducible AVNRT
in all patients with idiopathic VT including those with ILVT.
Wagshal AB, et
al.
4 also reported a case with
ILVT and AVNRT. That report had several differences with ours. Their patient
presented with ILVT, and AVNRT was discovered accidentally during EP study.
Ablation of slow pathway in their case resulted in cure of AVNRT and prevention
of spontaneous episodes of ILVT. They suggested that their case represented
an example of tachycardia induced tachycardia and hence ablation of AVNRT
resulted in cure of both arrhythmias. We can not exclude such a mechanism
in their case. In our case although ILVT has never been documented before
EP study, the patient remained asymptomatic after ablation of AVNRT only
following administration of verapamil. In addition we were not able to exclude
ILVT as arrhythmia responsible for some of his palpitation episodes. For
this reasons we decided to ablate ILVT rather continuing verapamil. Also,
Kautzner J, et al
5 in a recent
study on simultaneous idiopathic VT and AVNRT, has shown that ablation of
AVNRT dose not influence the induciblility of the idiopathic VT. Finally,
different methods have been proposed for ablation of ILVT
6,7,8,9.
We used the earliest PP during ILVT as a guide for RF ablation. As Lokhandwala
and his colleagues
10,11
has shown that PP by themselves are non-specific and are seen in normal people
during sinus rhythm, if PP wanted to be used as a guide for RF ablation of
ILVT, the
earliest PP
during tachycardia should be targeted.
Conclusion
This
case represents the co-incidence of ILVT and AVNRT and underscores the importance
of searching for dual AV node physiology and AVNRT in patients with ILVT.
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