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Luc A. Piérard , CHU Liège
Cardiomyopathie hypertrophique obstructive
Echocardiographie
Pronostic CMH
Bénigne et Stable
MortSubite
FA Progressiondes symptômes
Ins. cardiaque
STRATIFICATION DU RISQUE
GENETIQUEHistoire familiale de mort subiteMutations spécifiques
CLINIQUEArrêt cardiaque réaniméTV soutenue (>30 s) spontanéeSyncopes récidivantesTV au Holter
MORPHOLOGIQUE HVG sévère ( > 3 CM)
HEMODYNAMIQUE Gradient chambre de chasse( > 30 mm Hg)
Chute de PA à l’effort Réserve coronaire réduite
ECHOCARDIOGRAMME
- Hypertrophie septale asymétrique
- Distribution variable
- Parfois hypertrophie exclusivement apicale
- Mouvement systolique antérieur de la valve mitrale (SAM)
- Fermeture précoce de la valve aortique
ECHO DOPPLER
Formes obstructives
- Accélération du flux dans la chambre de chasse
- Maximum télésystolique : aspect en « lame de sabre »
- Gradient = 4 V2
- Régurgitation mitrale associée
- Variations du gradient en cas de pré- et post-charge (nitré)
Fonction diastolique
Etude du remplissage VG et Doppler tissulaire
. Trouble de relaxation
vs
. compliance
Maron et al NEJM 2003;348:295-303
HCM- RELATED DEATHVARIABLE
RELATIVE RISK p VALUE(95 % CI)
LV OUTLOW OBSTRUCTION ( > 30 mm Hg) 1.6 (1.1 - 2.4) 0.02
NYHA CLASS II, III, OR IV AT ENTRY 1.9 (1.2 - 2.9) 0.002
PAROXYSMAL OR CHRONIC ATRIAL AF 1.6 (1.1 - 2.4) 0.01
MAXIMAL LV THICKNESS > 30 mm 1.8 (1.1 - 2.8) 0.01
FEMALE SEX - 0.29
Maron et al NEJM 2003;348:295-303
Maron et al NEJM 2003;348:295-303
HCM- RELATED PROGRESSION TO NYHA
VARIABLE CLASS III OR IV OR DEATH FROM HEART FAILURE OR STROKE
RELATIVE RISK p VALUE (95 % CI)
LV OUTLOW OBSTRUCTION ( > 30 mm Hg) 2.7 (2.0 - 3.5) < 0.001
NYHA CLASS II, III, OR IV AT ENTRY 3.4 (2.4 - 4.8) < 0.001
PAROXYSMAL OR CHRONIC ATRIAL AF 1.3 (1.1 - 1.6) 0.046
MAXIMAL LV THICKNESS > 30 mm - 0.09
FEMALE SEX 1.4 (1.1 - 1.8) 0.02
Maron et al NEJM 2003;348:295-303
Maron et al NEJM 2003;348:295-303
SUDDEN DEATH FROM HCM
VARIABLE RELATIVE RISK p VALUE
(95 % CI)
LV OUTLOW OBSTRUCTION ( > 30 mm Hg) 1.9 (1.1 - 3.5) 0.014
NYHA CLASS II, III, OR IV AT ENTRY - 0.12
PAROXYSMAL OR CHRONIC ATRIAL AF - 0.72
MAXIMAL LV THICKNESS > 30 mm - 0.82
FEMALE SEX - 0.75
Maron et al NEJM 2003;348:295-303
Maron et al NEJM 2003;348:295-303
CONSEQUENCES OF CHRONIC OUTFLOW GRADIENT
Increase in LV wall stress
Myocardial ischaemia
Cell death
Fibrosis
HAEMODYNAMIC SUBGROUPS IN HCM
Obstructive : gradient at rest > 30 - 50 mmHg
Provocable :mild gradient at restgradient > 30 - 50 mmHg with provocation
Latent :no gradient at restsignificant gradient with provocation
Nonobstructive :gradient < 30 mmHg under basal and provocable conditions
INTERVENTIONS TO INDUCE GRADIENTS
Amyl nitrite inhalation
Valsalva maneuver
Post-PVC response
Isoproterenol infusion
Dobutamine infusion
Standing posture
Physiologic exercise (during and after)
GRADIENT MAJORE APRES EXTRASYSTOLE
GRADIENT MAJORE PENDANT MANŒUVRE DE VALSALVA
DOBUTAMINE STRESS ECHO
DOBUTAMINE INFUSION
LV OBSTRUCTION DURING DOBUTAMINE STRESS ECHO
232 consecutive pts : normal DSE (no HCM)
31 pts (13%):LVOT vel. >3m/s (36 mmHg)
7 unable toexercise
24 underwentEx stress echo
Possible angina : 19
Dyspnea : 4
Syncope : 1
DSE vs Ex SE IN 24 PATIENTS
17 women , 7 men
Hypertension in 12 pts
LVOT diameter : 22 ± 2 mm (18-25 mm)
Basal septal diastolic thickness : 13 ± 2 mm (9-15 mm)
Peak velocity with Dobutamine : 4 ± 0.8 m/s (3-6.3)
Peak velocity with Exercise : range 0.9 to 2.2 m/s
No patient developed LV gradient
EXERCISE FOR DEFINING LATENT OBSTRUCTION
Immediately following treadmill or bicycle exercise
During and immediately after semi-supine exercise
No drug withdrawal
Exercise Echo in HCM
EXERCISE ECHO IN HCM
320 consecutive patients
119 pts (37%) : LV outflow tract gradient > 50 mmHg at rest
201 pts : exercise echo106 (52%) : dynamic obstruction > 30 mmHg 76 (38%) : substantial gradient > 50 mmHg 95 (47%) : nonobstructive form (< 30 mmHg)
Thus : 225/320 pts (70%) : outflow obstruction
Implications : more candidates for septal reduction therapy ??
Maron et al Circulation 2006;114:2232-9
Maron et al Circulation 2006;114:2232-9
Maron et al Circulation 2006;114:2232-9
Maron et al Circulation 2006;114:2232-9
CONCLUSIONS
Obstruction to LV outflow has prognostic importance
No role of stress testing when baseline gradient > 30-50 mmHg
Preferred provocative maneuver : exercise
Measurement of gradient mandatory during and after exercise
Dobutamine stress testing should not be used
The prognostic importance of provocable obstructionremains unknown
SYMPTOMS
DrugsBeta-blockerVerapamilDisopyramide
Drugrefractorysymptoms
Obstructive HCM(rest or provocation)
Alternativesto surgery
SurgerySeptal myectomy
DDDPacing
Alcoholseptal ablation
Non-ostructive HCM(rest and provocation
End-stage HF treatment ,heart transplant
TRAITEMENT DE L ’OBSTRUCTION SYMPTOMATIQUE
- Chirurgie : myotomie + myectomie septale haute
- Alcoolisation de la première septale :
. épaisseur à cause de l’infarctus induit
. élimination de l’obstacle à l’éjection
. hospitalisation courte
. mortalité 2% (taux similaire à celui de la chirurgie)
. bloc AV complet 25%,nécessitant stimulateur
. rarement infarctus massif
. courbe d’apprentissage
- Effets morphologiques différents
SURGICAL MYECTOMY vs ALCOHOL SEPTAL ABLATION
Cine and contrast-enhanced CMR before and afterseptal myectomy (n=24)septal ablation (n=24)
Myectomy:resected tissue always localized to anterior septum
Ablation: more variable effect transmural tissue necrosis,more inferiorly in basal septum extending into RV side of septum at mid-ventricular level 6 pts: sparing of the basal septum with residual gradient
LBBB in 46% after myectomyRBBB in 58% after ablation
8 of 47 pts(17%) :heart block requiring PMK (excluded)Valeti et al JACC 2007;49:350-7