Irregular Heart
Beats/Palpitations
Anjan S Batra, M.D
Director of Electrophysiology
Associate Professor of Pediatrics
University of California-Irvine
CASE 1
•
A 12 year old presents with a fast heart rate. He
is otherwise asymptomatic. A wide complex
rhythm
h th iis noted
t d att a rate
t off 260 b
bpm. Hi
His bl
blood
d
pressure is 92/50. The next best course of
action would be:
January 14-15, 2011 SCA Conference
1
A.
B.
C.
D.
E.
Adenosine
Sotalol
Amiodarone
Verapamil
DC cardioversion
SVT
• In a hemodynamically stable patient,
a supraventricular
t i l ttachycardia
h
di with
ith
aberrant conduction is the most likely
rhythm.
• The best treatment for this patient
would be administration of adenosine
to terminate the tachycardia.
January 14-15, 2011 SCA Conference
2
CASE 2
An 8 year old presents with a fast heart rate and
difficulty breathing. Blood pressure is stable. An
ECG is obtained and shown below. There is no
change
g in the heart rate with adenosine. Your next
course of action would be:
A. DC cardioversion
B. Sedation and atrial overdrive pacing
C. Digoxin
D. Beta blockers
E. Verapamil
January 14-15, 2011 SCA Conference
3
Fascicular Ventricular
Tachycardia
• Originating from the left ventricle.
• Adenosine is usually not effective in
terminating the tachycardia.
• Calcium channel blockers are very
effective and hence this tachycardia is
also referred to as verapamil sensitive
ventricular tachycardia.
• This is usually amenable to ablation.
CASE 3:
A 12 year old boy is undergoing a stress test for
frequent ectopy at baseline. The echocardiogram at
rest was normal. You notice the following rhythm at
stage 5 of the standard Bruce protocol. The
diagnosis is most consistent with:
January 14-15, 2011 SCA Conference
4
A.
A
B.
C.
D.
E.
Brugada Syndrome
CPVT
Long QT type 3
Myocarditis
Artifact
Catecholaminergic ventricular
tachycardia (CPVT).
• Polymorphic ventricular tachycardia
with
ith exercise
i
• Brugada syndrome and long QT
type3
– polymorphic ventricular tachycardia
generally
g
y at rest or during
g sleep.
p
• Myocarditis: decrease in cardiac
function.
January 14-15, 2011 SCA Conference
5
CPVT
•
CPVT cannot be diagnosed on the basis of a resting ECG.1,2
•
Exercise stress testing is an important part of a CPVT workup.
– However, in as many as 20% of CPVT patients, formal exercise
stress testing will not produce ventricular ectopy.1
•
During exercise stress testing, bidirectional VT with a beat-to-beat 180degree rotation of the QRS complex is often observed.1
References: 1. Mohamed U, Napolitano C, Priori SG. Molecular and electrophysiological bases of catecholaminergic polymorphic
ventricular tachycardia. J Cardiovasc Electrophysiol. 2007;18:791-797. 2. Kontula K, Laitinen PJ, Lehtonen A, Toivonen L, Viitasalo M,
Swan H. Catecholaminergic polymorphic ventricular tachycardia: recent mechanistic insights. Cardiovasc Res. 2005;67:379-387.
Mutations in the Cardiac Ryanodine Receptor
Gene (RYR2) Are the Major Cause of CPVT
RYR2
•
12
60-65% of CPVT is
caused by mutations of
th cardiac
the
di ryanodine
di
receptor gene, which
encodes a
sarcoplasmic calcium
ion channel.1,2
References: 1. Mohamed U, Napolitano C, Priori SG. Molecular and electrophysiological bases of catecholaminergic polymorphic
ventricular tachycardia. J Cardiovasc Electrophysiol. 2007;18(7):791-797. 2. Hayashi M, Denjoy I, Extramiana F, et al. Incidence and
Risk Factors of Arrhythmic Events in Catecholaminergic Polymorphic Ventricular Tachycardia. Circulation. 2009;119:2426-34.
January 14-15, 2011 SCA Conference
6
It Is Important to Differentiate Between
CPVT and LQTS
• CPVT is an LQTS mimicker.1
• As many as 30% of CPVT patients have been
misdiagnosed as having “Long QT with normal QTc.”2,3
• Differentiating CPVT from LQTS is important for:
- Developing a comprehensive treatment plan
- Family-specific testing
13
References: 1. Choi G, Kopplin LJ, Tester DJ, et al. Spectrum and frequency of cardiac channel defects in swimming-triggered
arrhythmia syndromes. Circulation. 2004;110:2119-2124. 2. Priori SG, Napolitano C, Memmi M, et al. Clinical and molecular
characterization of patients with catecholaminergic polymorphic ventricular tachycardia. Circulation. 2002;106:69-74. 3. Napolitano C,
Priori SG. Diagnosis and treatment of catecholaminergic polymorphic ventricular tachycardia. Heart Rhythm. 2007;4:675-678.
Beta-blockers Do Not Provide Reliable Protection
Against Cardiac Arrhythmias Related to CPVT
• “However
However, in light of incomplete protection
afforded by beta-blockers in CPVT, its distinction
from long-QT is clinically relevant.”1
• Nearly 50% of CPVT patients taking a betablocker continue experiencing cardiac
arrhythmias and may require an ICD
ICD.1
14
Reference: 1. Priori SG, Napolitano C, Memmi M, et al. Clinical and molecular characterization of patients with catecholaminergic
polymorphic ventricular tachycardia. Circulation. 2002;106:69-74.
January 14-15, 2011 SCA Conference
7
Brugada Syndrome
• The ECG of patients with BrS is characterized by
– Coved- or saddleback-shaped ST-segment elevation
in leads V1 through V31
– complete or incomplete right bundle-branch
bundle branch block
1
– T-wave inversion
•
These ECG abnormalities may not be evident until unmasked by
infusion of a sodium channel blocker (flecainide or procainamide).1
References: 1. Brugada R, Brugada P, Brugada J, Hong K. Brugada syndrome. Gene Reviews Web site. Available at:
http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=brugada. Accessed May 25, 2009. 2. Rossenbacker T and Priori SG.
The Brugada Syndrome. Curr Opin Cardiol. 2007;22:163-70.
BrS Typically Presents in
Men 30-40 Years of Age
•
The most common presentation of BrS is a man 30-40 years of
age with malignant arrhythmias and a history of syncope
syncope.1,2
– Men are 8-10 times more likely than women to have the BrS
phenotype.1,2
– There is no difference between men and women in the prevalence
of gene mutations associated with BrS.1,2
16
•
Men with an abnormal ECG and inducible ventricular
arrhythmias have a poor prognosis.1,2
•
If untreated, men with BrS have a 45% chance of having a
cardiac event over the course of their life.1
References: 1. Brugada R, Brugada P, Brugada J, Hong K. Brugada syndrome. Gene Reviews Web site. Available at:
http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=brugada. Accessed May 25, 2009. 2. Rossenbacker T and Priori SG.
The Brugada Syndrome. Curr Opin Cardiol. 2007;22:163-70.
January 14-15, 2011 SCA Conference
8
CASE 4
• A 14 year old patient with a history of WPW
and SVT presents with this ECG. He is
alert and hemodynamically stable. The
MOST appropriate therapy is:
A. Adenosine
B. Lidocaine
C. Observation
D. DC cardioversion
E. IV calcium channel blocker
January 14-15, 2011 SCA Conference
9
WPW
• Atrial fibrillation with rapid conduction
over the
th accessory pathway
th
results
lt iin
a rapid ventricular response.
• At risk for ventricular fibrillation and
compromised circulation.
• Adenosine can also induce atrial
fibrillation.
• DC Cardioversion should be readily
available.
CASE 5
• A 12 year old boy comes to you with palpitations
with exercise. He also complains of occasional
chest pain with exercise. You obtain an ECG
which is shown below. The next most obvious
recommendation would be to:
January 14-15, 2011 SCA Conference
10
•
•
•
•
•
a. Perform an exercise stress test.
b. Clear him for sports without any restrictions.
c. Perform an echocardiogram.
d. Perform a CXR.
e. Perform a 30 day event monitor.
Left ventricular hypertrophy
with a strain pattern.
• At risk for ventricular tachycardia and
sudden
dd cardiac
di death
d th with
ith exercise
i
• Additional risk factors
– family history of premature sudden death
– extreme LV hypertrophy (> 30 mm)
– NS ventricular tachycardia on Holter
– unexplained (not neurally mediated)
syncope
January 14-15, 2011 SCA Conference
11
The Clinical Presentation of HCM
•
HCM is a progressive disease associated with varying degrees of LVH with
no apparent cause.1
-
23
Thickening typically develops during late childhood and throughout
adolescence.1
Reference: 1. Keren A, Syrris P, McKenna WJ. Hypertrophic cardiomyopathy: the genetic determinants of clinical disease expression.
Nature. 2008;5:158-168.
Obstructive and Non-obstructive HCM
LVH is usually maximal in the interventricular
septum, but other localized variants have been
documented.1
24
Reference: 1. Keren A, Syrris P, McKenna WJ. Hypertrophic cardiomyopathy: the genetic determinants of clinical disease expression.
Nature. 2008;5:158-168.
January 14-15, 2011 SCA Conference
12
The Clinical Diagnosis of HCM Relies
Primarily on Echocardiogram
Echocardiogram can help determine:
•
Location and extent
of hypertrophy
•
Systolic and diastolic function
•
The presence and degree
of systolic anterior motion
•
The severity of subaortic
and/or midventricular
obstruction
•
Direction and degree of mitral regurgitation
•
The presence or absence of additional mitral valve abnormalities
•
Left atrial size
25
QUESTIONS
January 14-15, 2011 SCA Conference
13
CASE 6
A 21 year old patient with classic Fontan presents with palpitations
and fast heart rates for 3 days. ECG shows an unvarying heart
rate of 140 bpm. He usually has a heart rate between 60 to 90
bpm. His blood pressure is stable. The following ECG is
obtained. The next most appropriate
pp p
intervention would be:
•
•
•
•
•
a.
b.
c.
d.
e.
Echocardiogram
Digoxin
Adenosine
Sotalol
Amiodarone
January 14-15, 2011 SCA Conference
14