Chapter 16 Supraventricular ArrhythmiasSpecial circumstances
Pregnancy
There is concern about adverse hemodynamic effects
of cardiac arrhythmias during pregnancy. In addi-
tion, there is concern about the tetragenic effects of
cardiovascular agents (especially within the fi rst 2
months). It is important to consider ablation proce-
dures for care of arrhythmias prior to pregnancy. In
terms of acute management of SVA, use of vagal
maneuvers adenosine or D/C shock for acute car-
dioversion of SVA is safe for both mother and fetus.
Other drugs used for acute treatment are listed in
Table 16.9.
Chronic therapy should be used only if symptoms
are intolerable or if the tachycardia results in hemo-
dynamic compromise. In resistant cases, catheter
ablation may be used as a last resort, always mindful
to expose mother and fetus to minimal radiologic
exposure.
Since publication of the guidelines, the safety in
use of ibutilide has been reported [38]. In addition,
several studies have shown the effi cacy of ablative
procedures for drug resistant cases of SVT [39,40].
Future directions
There are a number of projected exciting future
developments related to SVT.
In the future we look forward to modifi cations in
the computerized surface ECG analyses of rhythm
disturbances allowing for ready incorporation of the
existing criteria as described in the text. For example,
electronic caliper measurements of specifi c ECG
forms during tachycardia will facilitate arrhythmia
diagnoses. In addition, newer diagnostic pacing
techniques allow for more effi cient and accurate
diagnoses of the types of SVT encountered in the
catheter laboratory. As our knowledge in this area
grows we anticipate a broader range of diagnostic
maneuvers to help pinpoint the diagnoses of the
more complex arrhythmias particularly the left atrial
scar-related fl utters.
Newer drugs are currently being actively tested,
particularly for patients with atrial fi brillation and
fl utter. These drugs include dronedarone, a
homologue of amiodarone, which has been found
to be effective but without major toxicities found to
be associated with the parent drug.
Hopefully, a derivative of dronedarone will prove
effective and safe for those patients with congestive
heart failure. In addition, there is great interest in
the development of drugs which are atriospecifi c.
These agents exert their primary actions on atrial
rather than ventricular tissue and hopefully avoid
the development of torsades. One such agent is cur-
rently under review (Vernakalant) and appears to be
effective and safe for acute conversion of atrial fi bril-
lation and fl utter. This drug may serve as the
forerunner for a whole new approach for drug
management of SVT.
There have been enormous strides in refi nement
of catheter ablative techniques which hold much
promise for the future. These techniques include use
of robotics or stereotaxis for precise catheter manip-
ulation. Use of these techniques allow for the clini-
cian to better manage complex SVT problems, as
our found in patients with postatrial fi brillation
ablation scars, as well as for complex surgical con-
genital corrections complicated by SVT. In addition,
ablation of these complex arrhythmias are also facil-
itated by integration of CT anatomical details with
intracardiac mapping tools.
These advances will allow for more precise defi ni-
tion and treatment of complex supraventricular
arrhythmias. In addition to better mapping tools, a
number of centers are experimenting with newer
energy forms including laser, high energy ultra-
sound and microwave. The successful marriage of
industry and interventional cardiac electrophysiol-
ogy portends the development of tools that
will allow for better treatment for these
patients.References available online at http://www.Wiley.com/go/
AHAGuidelineHandbook.During the production of this book this relevant AHA
statement and guideline was published: Sleep Apnea
and Cardiovascular Disease, http://circ.ahajournals.
org/cgi/reprint/CIRCULATIONAHA.107.189420.