Arrhythmic Risk and Aortic Stenosis
Aortic Stenosis: Etiology ü Congenital bicuspid valve is the most common abnormality ü Rheumatic heart disease and degeneration with calcification are found as well
Normal
Bicuspid Ao-V
Calcific valve
Common Clinical Scenarios ü Younger people ü Functional murmur vs MVP vs bicuspid AV
ü Older people ü Aortic sclerosis vs aortic stenosis
Pathophysiology of Aortic Stenosis ü Left ventricular outflow obstruction ü LV systolic pressure > aortic pressure
ü Concentric left ventricular hypertrophy ü Sustains high LV pressures ü Normalizes wall stress (radius x pressure/wall thickness) ü Eventually results in impaired LV diastolic compliance
ü LA hypertrophy and enlargement ü Severe stenosis: Limits ability to increase stroke volume on demand Critical aortic stenosis = fixed cardiac output
Natural History of Aortic Stenosis ü Long asymptomatic “latent” period ü “Cardinal” symptoms of severe aortic stenosis ü Dyspnea ü Angina ü Syncope
ü Sudden death ü Left ventricular dilatation and contractile failure ü Endocarditis ü Arrhythmias ü Ventricular tachycardia ü Conduction system disease ü Atrial fibrillation
Mechanisms of Syncope in Aortic Stenosis ü Fixed cardiac output: Vasodilation (exercise, vagal stimulation, drug induced), inability to augment CO, drop in cerebral perfusion pressure. ü Heart block: Ca++ deposits in aortic ring encroach upon conduction tissue ü Ventricular arrhythmias (LVH, ischemia)
Which of these patients is most likely to have syncope?
A 75 year old man has recurrent seizures. Holter ECG monitoring during a seizure.
What is the appropriate management?
Predictors of Risk for MI, HF, Death ü Unstable Coronary Syndrome ü angina, acute or recent MI
ü Decompensated Heart Failure ü new onset, worsening HF, NYHA Class IV
ü Significant Arrhythmias ü high grade AV block, symptomatic or new ventricular arrhythmia, ü tachycardia with rate > 100, symptomatic bradycardia
ü Severe Valvular Disease ü severe aortic stenosis, symptomatic mitral stenosis
Left Bundle Branch Block
Bifascicular Block
Trifascicular Block
Complete AV Block
Diagnostic Value of ECG ü Preexisting conduction disturbance ü WPW Syndrome ü ECG aspects of genetic syndromes
Oreto G. I Disordini del Ritmo Cardiaco - CSE 1997
Narrow QRS Tachycardia
Wide QRS Tachycardia
“…le conclusioni più importanti possono dipendere da particolari apparentemente trascurabili….” Sherlock Holmes Oreto G. I Disordini del Ritmo Cardiaco - CSE 1997
Valvular disease and Sudden Death ü Aortic stenosis (predominate) ü The mechanism of sudden death is unclear, and both malignant ventricular arrhythmia and bradyarrhythmia have been documented
Underlying Arrhythmias of SD Torsades de Pointes 13% Bradycardia 17% VT 62%
Bayés de Luna A. Am Heart J. 1989;117:151-159.
Primary VF 8%
Pathological Progression of CV Disease Arrhythmia
Coronary artery disease Underlying etiology in ~60% of CHF 1
Left ventricular injury
Pathologic remodeling
Low ejection fraction
Pump failure
ü Hypertension ü Cardiomyopathy ü Valvular Disease Underlying etiology in ~40% of CHF 1
Death
ü Neurohormonal stimulation ü Endothelial dysfunction ü Myocardial toxicity ü Vasoconstriction ü Renal sodium retention
Symptoms: Dyspnea Fatigue Edema
1 Adapted from Cohn JN. N Engl J Med. 1996;335:490–498. 2 He J, Ogden LG, Bazzano LA, et al. Risk Factors for Congestive Heart Failure in US Men and women: NHANES I epidemiologic follow-up study. Arch Intern Med 2001, 161: 996-1002.
Chronic heart failure
LVEF and SCA Incidence % SCA Victims
8
7.5%
7 6
5.1%
5 4
2.8%
3 2
1.4%
1 0 0-30%
31-40%
LVEF Vreede-Swagemakers JJ. J Am Coll Cardiol. 1997;30:1500-1505.
41-50%
>50%
Risk of Sudden Death: GISSI-2 Trial 1.00
1.00
0.98
p log-rank 0.002
0.96
Survival
Survival
0.96
0.98
0.94 0.92
0.94 0.92
0.90
0.90
0.88
0.88
p log-rank 0.0001
A
B
0.86
0.86 0
30
60
90
120
150
180
0
Days
Patients without LV Dysfunction (LVEF >35%) Maggioni AP. Circulation. 1993;87:312-322.
30
60
90
120
Days No PVBs 1-10 PVBs/h > 10 PVBs/h
Patients with LV Dysfunction (LVEF < 35%)
150
180
Prevalence and Prognosis of Ventricular Dysynchrony LBBB More Prevalent with Impaired LV Systolic Function Preserved LVSF (1) Impaired LVSF (1) Mod/Sev HF (2)
Increased All-Cause Mortality with Wide QRS at 45 Months (3) P < 0.001
8%
49% 34%
24%
QRS < 120 ms
38%
1. Masoudi, et al. JACC 2003;41:217-23 2. Aaronson, et al. Circ 1997;95:2660-7
QRS > 120 ms
3. Iuliano et al. AHJ 2002;143:1085-91
Ventricular dysynchrony impairs diastolic and systolic function 4-6: Reduced LV filling time; Increased mitral regurgitation; Depressed dP/dt 4. Grines, et al. Circulation 1989;79:845-53 5. Xiao, et al. Br Heart J 1991;66:443-7 6. Xiao et al. Br Heart J 1992;68:403-7
Diagnostic Yield Test
Appropriate
Diagnostic
NND
History and physical exam
308 (100%)
47 (15%)
7
ECG
241 (78%)
25 (10%)
10
Holter ECG
82 (27%)
13 (16%)
6
EPS
51 (17%)
14 (27%)
4
Europace 2002; 4: 351-356
NYHA
Ischemia
SD
FE
QT d
EPS
VPBs/nsVT
QRS d
Markers of Arrhythmic Risk ü Simple “descriptors” ü Prognostic Indicators ü Decision-making
?
MEDTRONIC – CORE VALVE Incidenza d’Impianto di Pacemaker ü Impianto della protesi nel tratto di efflusso del VS dove il meccanismo di auto espansione del nitilolo può interferire con il sistema di conduzione, soprattutto vero nei pazienti anziani che hanno già di base disturbi di Conduzione (BBDx, EASn; BBSn, Blocchi A-V di vario grado) ü Dai dati di J. La Borde emerge in modo inequivocabile che un impianto di circa 4-6 mm al di sotto del piano valvolare aortico si associa ad un’incidenza di impianto di pacemaker dal 7% al 15%
(Roten L, Windecker S, Hellige G, et al. Eur Heart J 2009;30 (suppl 1):606)
FRANCE Registry Complicanze Maggiori a 30 Giorni
PCR 2010
Selection of Pacemaker Systems for Patients With AV Block
AV block Chronic atrial tachyarrhythmia, reversion to sinus rhythm not anticipated
No
Desire for AV synchrony No
Ventricular pacemaker
Desire for rate response
No
Yes
Desire for rate response No
Yes
No
Desire for atrial pacing
Yes
Ventricular pacemaker
Rate-responsive ventricular pacemaker
Yes
Yes
Rate-responsive ventricular pacemaker
Single-lead atrial sensing ventricular pacemaker
Desire for rate response No
Epstein A, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. J Am Coll Cardiol 2008; 51:e1–62. Figure 1.
Dual-chamber pacemaker
Yes Rate-responsive dual-chamber pacemaker
Selection of Pacemaker Systems for Patients With Sinus Node Dysfunction
Sinus Node Dysfunction Evidence for impaired AV conduction or concern over future development of AV block
No
Yes
Desire for rate response
No
Atrial pacemaker
Desire for AV synchrony
No
Yes
Rate-responsive atrial pacemaker
Yes
Desire for rate response
Desire for rate response
No
Ventricular pacemaker Epstein A, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. J Am Coll Cardiol 2008; 51:e1–62. Figure 2.
Yes
Rate-responsive ventricular pacemaker
No
Dual-chamber pacemaker
Yes
Rate-responsive dual-chamber pacemaker
Siti di Stimolazione Cardiaca (para-HIS)
AP
Siti di Stimolazione Cardiaca (RVOT)
LAO
Preoperative Risk Evaluation “Prepares the Patient to TAVI”
