Download Management of Non-Sustained Ventricular Tachycardia

MANAGEMENT OF NONSUSTAINED VENTRICULAR
TACHYCARDIA
Troy Hounshell, DO
Iowa Heart Center
Heart Rhythm Center
Disclosures
• Harvard Clinical Research Institute
• Medtronic
• Milestone Pharmaceuticals, Inc.
• St. Jude Medical
• Employee-Iowa Heart Center/Mercy-Des Moines
Objectives
• Discuss NSVT and its relation to different clinical
etiologies
• To discuss NSVT risk in relation to SCD
• Discuss treatment of NSVT in its presenting clinical
setting
Definition
• There can be many different definitions
• Nonsustained ventricular tachycardia (NSVT) is defined
as 3 (sometimes 5) or more consecutive beats arising
below the atrioventricular node with a heart rate of >100
beats/min and lasting <30 s.
The Concern
• In several clinical settings, NSVT is a marker of increased
risk for subsequent sustained tachyarrhythmias and
sudden cardiac death (SCD), whereas it may have no
prognostic significance in others.
Eur Heart J 2004;25:1093–9
Goal in Managing NSVT
• Detect those apparently healthy individuals in whom
NSVT represents a sign of occult disease, and to risk
stratify patients with known disease who present with this
arrhythmia to provide therapy that mitigates associated
risks.
NSVT with Normal Heart
• How to Evaluate
• History (Age/PMHx/FMHx/Medications)
• 12 Lead ECG
• Channelopathy (Brugada/Long QT/Early Reoplarization/ARVD/etc)
• How does it respond to exercise?
• Suppression with exercise is a marker of benign clinical course**
• NSVT during recovery is a better predictor if increase mortality than
NSVT during exercise only*
• NSVT in athletes is benign and has no adverse prognostic significance
(assuming a structural normal heart and channelopathies are
excluded)**
*N Engl J Med. 2003;348:781–90.
**J Am Coll Cardiol 2002;40:446 –52
**Eur Heart J 2008;29:71– 8
**Am J Cardiol 2008;101:1792–5.
J Am Coll Cardiol 2012;60:1993–2004
Idiopathic VT
• Typically referred to as outflow tract tachycardia's
• Benign arrhythmia
• May be sustained or repetitive monomorphic NSVT
• Usually a result of triggered activity from heightened
intracellular calcium
• Usually a LBBB (RVOT) inferior axis with transition
usually occurring around V4
• Can be RBBB (LVOT) with inferior axis. Transition usually
occurring around V1-V2
• Treatment aimed at symptoms and typically occurs with
BB, CCB. Many times BB with Class IC antiarrhythmic are
used for efficacy
Idiopathic vs Arrhythmogenic Right
Ventricular Dysplasia
Idiopathic VT
ARVD
• RBBB or LBBB
• QRS Lead I >120ms
• Inferior Axis
• Earliest-onset QRS V1
• Transition at V4 or V1-2
• QRS notching
• Transition V5 or later
J Am Coll Cardiol 2011;58:831– 8
JACC Vol. 58, No. 8, 2011
JACC Vol. 58, No. 8, 2011
NSVT with Hypertension and Valvular
Heart Disease
Hypertension
Valvular Heart Disease
• Burden closely correlates
• High correlation between
with LVH
• No convincing evidence to
suggest increased risk of
SCD
• Should have evaluation
for IHD
• Treat hypertension
aggressively
NSVT and VHD
• NSVT marker of LV
pathology
• No evidence to suggest
NSVT predicts SCD even
after valve replacement
• Treat valve disease
Am J Cardiol 1992;69:913–7
Circulation 1997;96: 500–8
Am Heart J 1987;113:1298-307
N Engl J Med 1987;317:787–92
NSVT and Coronary Artery Disease
NSTEMI
NSTEMI
Am J Cardiol 2011;108:1373–81
NSVT and Coronary Artery Disease
• After the reperfusion era evidence now exists to suggest
that NSVT no longer carries independent risk death in IHD
once other factors like EF are taken into account*
• CARISMA study showed EF <40% with NSVT (> 125
BPM >16 beats <30s) showed no association with cardiac
death over 2 years after multivariable analysis**
*Circulation 1997;96:1888 –92
*Circulation 1993;87:312–22
*J Am Coll Cardiol 1999;33:1895–*902
*Circulation 2001;103:2072–7
*Eur Heart J 2005;26:762–9
**Circulation 2010;122:1258–64
NSVT and Coronary Artery Disease
• When to study?
• MUSTT trial (EF <40%)
• Evaluated in hospital vs post hospital presentation of NSVT*
• Patients post surgical revascularization with NSVT showed worse
outcomes when NSVT occurred late after surgery vs early*
• An exception seems to be patients with early NSVT post surgery
with sustained VT at EPS. These patients had poor outcomes**
• Other modalities
• Heart rate variability, T-Wave alternans
• Not well delineated to warrant routine use
*J Am Coll Cardiol 2001;38:1156–62
*J Cardiovasc Electrophysiol 2002;13:757– 63
**J Cardiovasc Electrophysiol 2002;13:342– 6
NSVT and LV Dysfunction/ Congestive
Heart Failure
• NSVT in this population is common and can be as high as
80%
• Two studies CHF-STAT and PROMISE failed to show
NSVT to predict SCD or total mortality*
• Only in the recovery period of exercise does “severe
ectopy” show adverse prognostic significance**
• In patients with idiopathic dilated cardiomyopathy NSVT
and LVEF <30% showed 8 fold increase in arrhythmia risk
compared to other groups. NSVT by itself was not
predictive.***
*N Engl J Med 1995;333:77– 82
*Circulation 2000;101:40–6
**J Am Coll Cardiol 2004;44:820–6
***Circulation 2003;108:2883–91
Special Populations
• HOCM
• Incidence of 20-30%
• Appears to be related to myocardial fibrosis as MRI delayed
enhancement and echo strain relate to presence of NSVT
• Associated with worse LVH and more symptomatic HCM
• High risk factors
• Syncope
• Frequent NSVT
• FMHx SCD young age
• Severe LVH (Wall thickness >30mm)
• Abnormal BP response to exercise
• Zero to one risk factor shows ~1% risk SCD (low)
• 2 or more risk factors have high SCD risk
J Am Coll Cardiol 2003;42:873–9
J Am CollCardiol 2005;45:697–704
Heart 2004;90:570–575
Special Populations
ARVD
• A condition of fibrofatty infiltration
of the myocardium classically in
the right ventricle (can be left
ventricle) resulting in
cardiomyopathy and eventual RV
dyfunction
• Increased risk for SCD
• Patient can present with
asymptomatic NSVT and be at
increased risk for SCD
• NSVT may be monomorphic or
Polymorphic
Giant Cell Myocarditis
• Usually sustained
arrhythmias with high
SCD risk
Repaired TOF
• 50% will have NSVT with
4-14% prevalence of
sustained VT
• Inducible Sustained VT is
marker of subsequent
events