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

Sherlock Holmes

“…le conclusioni più importanti possono

dipendere da particolari apparentemente trascurabili….”

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

Bayés de Luna A. Am Heart J. 1989;117:151-159.

Underlying Arrhythmias of SD

Bradycardia 17%

VT 62%

Primary VF 8%

Torsades de Pointes 13%

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.

Pathologic remodeling

Low ejection fraction Death

Symptoms: Dyspnea Fatigue Edema

Chronic heart

failure

ü Neurohormonal stimulation

ü Endothelial dysfunction

ü Myocardial toxicity ü Vasoconstriction ü Renal sodium

retention

Arrhythmia

Pump failure

Coronary artery disease

ü Hypertension ü Cardiomyopathy ü Valvular Disease

Left ventricular injury

Pathological Progression of CV Disease

Underlying etiology in ~60% of CHF 1

Underlying etiology in ~40% of CHF 1

LVEF and SCA Incidence

Vreede-Swagemakers JJ. J Am Coll Cardiol. 1997;30:1500-1505.

LVEF

% S

CA

Vic

tims

7.5%

5.1%

2.8%

1.4%

0 1 2 3 4 5 6 7 8

0-30% 31-40% 41-50% >50%

Risk of Sudden Death: GISSI-2 Trial

Patients without LV Dysfunction

(LVEF >35%)

Maggioni AP. Circulation. 1993;87:312-322.

Patients with LV Dysfunction

(LVEF < 35%)

No PVBs

1-10 PVBs/h

> 10 PVBs/h

0.86

A

0.88

0.90

0.92

0.94

0.96

0.98

1.00

0 30 60 90 120 150 180

Days

Su

rviv

al

p log-rank 0.002

0.88

0.90

0.92

0.94

0.96

0.98

1.00

0 30 60 90 120 150 180

Days

Su

rviv

al

B

p log-rank 0.0001

0.86

Prevalence and Prognosis of Ventricular Dysynchrony

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

Increased All-Cause Mortality with Wide QRS at 45 Months (3)

34%

49%

QRS < 120 ms

QRS > 120 ms

3. Iuliano et al. AHJ 2002;143:1085-91

P < 0.001

LBBB More Prevalent with Impaired LV Systolic Function

38%

24%

8%

Mod/Sev HF (2)

Impaired LVSF (1)

Preserved LVSF (1)

1. Masoudi, et al. JACC 2003;41:217-23 2. Aaronson, et al. Circ 1997;95:2660-7

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

Diagnostic Yield

Europace 2002; 4: 351-356

NYHA

VPBs/nsVT

Ischemia

SD

QT d QRS d

FE

EPS

Markers of Arrhythmic Risk

ü Simple “descriptors”

ü Prognostic Indicators

ü Decision-making ?

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%

MEDTRONIC – CORE VALVE Incidenza d’Impianto di Pacemaker

(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

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.

AV block

Chronic atrial tachyarrhythmia,

reversion to sinus rhythm not anticipated

Desire for AV

synchrony

Desire for rate response

No Yes

Desire for rate response

No

Desire for atrial pacing

Yes

Ventricular pacemaker

Rate-responsive ventricular pacemaker

No Yes

Single-lead atrial sensing ventricular

pacemaker Desire for rate

response

Dual-chamber pacemaker

Rate-responsive dual-chamber pacemaker

No Yes

No Yes

Ventricular pacemaker

Rate-responsive ventricular pacemaker

No Yes

Yes No

Sinus Node Dysfunction

No

Atrial pacemaker Rate-responsive atrial pacemaker

Rate-responsive dual-chamber

pacemaker

Dual-chamber pacemaker

Ventricular pacemaker

Rate-responsive ventricular pacemaker

Yes

No Yes No Yes

No Yes

Selection of Pacemaker Systems for Patients With Sinus Node Dysfunction

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.

Evidence for impaired AV conduction or concern over future development of AV block

Desire for rate

response

Desire for AV synchrony

Desire for rate

response

Desire for rate

response

Siti di Stimolazione Cardiaca (para-HIS)

AP

Siti di Stimolazione Cardiaca (RVOT)

LAO

Preoperative Risk Evaluation “Prepares the Patient to TAVI”