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Killer that claims four young lives each week Daily Express - 31st August 2004By Hilary Freeman
Parents call for action on sudden deaths - Jo Revill Health Editor
The Observer - 13th June 2004
Teenager collapses dancing with friendsDaily Mail - 17th May 2004
Unexpected tragediesCycling Weekly - 17th April 2004
Hypertrophic Obstructive Cardiomyopathy
Presenter- Dr. Jyotindra Singh
Functional ClassificationDilated (Congestive, DCM, IDC)– Ventricular dilation, hypokinetic
left ventricle, and systolic dysfunction
Hypertrophic (IHSS, HCM, HOCM, ASH)– Inappropriate myocardial
hypertrophy, with or without left ventricular obstruction
Restrictive (Infiltrative)– Abnormal ventricular filling with
diastolic dysfunction
Arrhthymogenic Right Ventricular (ARVD)– Fibroadipose replacement of
right ventricle
HOW DO WE DEFINE HOCM? IDIOPATHIC HYPERTROPHIC
SUBAORTIC STENOSIS
A myocardial disease characterized by
Asymmetric hypertrophy of IVS & ventricles (LV > RV)
Microscopic evidence of myocardial fiber disarray & fibrosis
Variable dynamic obstruction that is usually sub aortic & is associated with abnormal SAM of AML
Prevalence of HCM in the general population is about 1 in 500 (0.2%).
2
Historical PerspctiveHCM was initially described by Teare in 1958
Braunwald was the first to diagnose HCM clinically
Goodwin & colleagus- namd it HOCM
SAM was described by Fix in 1964
Brock (1957) & Cleland (1958) did Ist myotomy- myectomy
Dobell & scott / Lillehi & Levy- LA approach
Cooley & colleagues- RV approach
Background
Genetic disorderÞ Autosomal dominant
Molecular basis Þ beta myosin heavy chain & Þ Myosin binding protein C
Myocardial Ca++ kineticsÞ Increase Ca++ intracellular
hypertrophy and cellular disarray
Leading cause of sudden death in preadolescent and adolescent
HOCM VARIANTS- Morphology
2
LV CAVITY
Sub aortic -Small sizeSigmoid
shaped
Midventricular -Dumbbell shaped – prone for LV
apical aneurysm.
Apical- Spade shaped
Advanced disease-LV dilation
Mitral Valve
Dynamic morphology
Obstruction in LVOT
Positioned closer to ventricular septum
Disproportionately elongated & thickened Leaflets -AML
PML closes against the body of elongated AML- junction of Middle & free edge
Fate of RV- LA-CoronariesRV RVOTO d/t Distorted IVS shape
RVH P HTN d/t long standing LVH
LA ----Dilated & thickened ----Reduced LV compliance / MR
Coronaries---Large / Prominent muscular bridging (Total systolic occlusion) ---Wall thickening & luminal narrowing of septal branches
Histopathology
Increased fibrous tissue
Increase muscle cell diameter
Increase in number of cell layers
Abnormalities in orientation of myofibrils.
Avg degree of disarray is 30%( >5% is diagnostic of HOCM)
Pathophysiology Involves 4 interrelated processes:
–LVOT
–Diastolic dysfunction
–Myocardial
ischemia
–Mitral regurgitation
Physiological consequences -LVOTElevated intraventricular pressures
Prolongation of ventricular relaxation
Increased myocardial wall stress
Increased oxygen demand
Decrease in forward cardiac output
DIASTOLIC DYSFUNCTION
Diastolic Dysfunction- Due to prolongation of isovolumic relaxation
time - LV filling pressure- Ventricular volume- Atrial contribution to ventricular filling ~ 75%
Poor Compliance- LVEDP for any LVEDV - Subendocardial ischemia
Myocardial Ischemia
Myocardial muscle mass
Myocardial oxygen demand
( wall stress)
Diastolic filling pressures
Coronary capillary density
Vasodilatory reserve
Abnormal intramural
coronary arteries
Systolic compression
of coronary arteries
Small-Vessel Disease and the Morphologic Basis for Myocardial Ischemia in HCM(A) Native heart of a patient with end-stage HCM who underwent transplantation. Large areas of gross macroscopic scarring are evident throughout the LV myocardium(white arrows). (B) Intramural coronary artery in cross-section showing thickened intimal and medial layers of the vessel wall associated with small luminal area. (C) Area of myocardium with numerous abnormal intramural coronary arteries within a region of scarring, adjacent to an area of normal myocardium.
MITRAL REGURGITATION/SAM
SAM: (Bernoulli effect)Þ dynamic pressure gradient
across LV outflow tract
Þ midsystolic intraventricular obstruction of the flow
SAM - Septal Contact dynamic obstruction
increased by:
afterload
contractility
SAM (Classical of HOCM)
At systole -PML closes against mid part of AML
(Not the free edge)
On AML venturi effect of high velocity of blood stream
(D/t rapid & early ventricular ejection)
Free edge hinges on rest of leaflet & angulates towards
aortic valve & contacts with IVS
LVOTO MR
– Results from the systolic anterior motion of the mitral valve
– Usually mid / late systolic– Jet is directed posteriorly– Severity of MR directly
proportional to LV outflow obstruction
Usually relieved after relief of LVOTO.
– Results in symptoms of dyspnea, orthopnea
Mitral Regurgitation
Electrical disturbances
Paroxysmal supraventricular arrhythmias (30-50%)
- result in shorter diastolic filling time; - patients have palpitations, shortness of breath, syncope
Atrial fibrillation (15-20%)
- poorly tolerated – the time for diastolic filling decreased
Non-sustained ventricular
tachycardia (25% ) - occurs during ambulatory monitoring
Sustained ventricular tachycardia/ventricular fibrillation
19
Dizziness: by
Exertion
Hypovolemia
Maneuver (rapid standing or valsalva)
Medication (diuretics, NTG and Vasodilator Meds)
Arrhythmia hypotension decrease cerebral perfusion
Dyspnea: – Most common symptom, 90%– Lt Ventricular Diastolic filling
pressure PAP
Orthopnea and Paroxysmal Nocturnal Dyspnea:– Pulmonary venous congestion– Early signs of CHF
SYMPTOMS
20
Angina:– Common with no CAD– Impaired diastolic relaxation + MVO2 Sub-endocardial
ischemia– Capillary density leads to flow to hypertrophic muscle– Extramural compression of coronaries– Systolic ejection time leads to diastolic interval for
coronaries perfusion
Syncope and pre-syncope:– Very common– CO with exertion or arrhythmia– High risk of sudden death– Urgent work-up and aggressive treatment
SYMPTOMS
21
SYMPTOMSPalpitation:– Ventricular Arrhythmia75%– SVT 25%– A- fib 5-10%
Sudden cardiac death (SCD): – 6 % in children – Related to extreme
exertion– MCC of SCD is arrhythmia
80 % ~ V-fib
22
PHYSICAL SIGNSDouble apical impulse:– Forceful left atrial contraction
against non-compliant ventricle
S1: normal
S2: normal or paradoxical split
S3 gallop: decompensated Lt. ventricle
S4: atrial systole against hypertrophic ventricle
Jugular venous pulse: prominent a- wave
Double carotid arterial pulse: declines in mid systole as gradient develop
23
MURMURSSystolic Ejection Murmur:
Crescendo - Decrescendo– Between apex and left
sternal border– Radiate to suprasternal
notch– by
Preload (volume loading)
Afterload(vasopressor)
– by Preload (nitrates, diuretic, standing)
Afterload (vasodilator)
24
MURMURSHolosystolic Murmur of MR:– Retrograde ejection of
blood flow into low pressure left atrium
– Best heard at apex and axilla
– Pt. with SAM* and significant LV outflow gradients
Diastolic Decrescendo Murmur of AR: 10% of Pt.
*
Murmur intensity increases
( reduced LV size ---- raises level of obstruction)--Reduced Preload – valsalva/ standing/ tachycardia
--Reduced after load -- nitro vasodilators--Raised contractility – Ionotropes, exercise
Murmur intensity decreases
--Increased preload -- squatting, hand grip --Increased after load --Reduced contractility – B blockers, CCB
DIAGNOSTIC EVALUATION-ECGLVH - increased precordial voltages and non-specific ST segment and T-wave abnormalities.
Asymmetrical septal hypertrophy produces deep, narrow (“dagger-like”) Q waves
infarction Q waves are typically > 40 ms duration while septal Q waves in HCM are < 40 ms.
Lateral Q waves are more common than inferior Q waves in HCM.
compensatory left atrial hypertrophy, with signs of left atrial enlargement (“P mitrale”) on the ECG.
Atrial fibrillation and supraventricular tachycardias are common.
Ventricular dysrhythmias (e.g. VT) also occur and may be a cause of sudden death.
Date of download: 3/28/2013
Copyright © The American College of Cardiology. All rights reserved.
(A) Parasternal long-axis view depicting severe asymmetric septal hypertrophy and systolic anterior mitral valve motion (arrowhead);
(B) M-mode across the mitral leaflets depicting prominent systolic anterior motion (thick arrows) of the anterior mitral leaflet (SAM);
(C) M-mode tracing across the aortic valve demonstrating partial closure of aortic leaflets (arrowheads); and (D) accentuation of late-peaking dynamic left ventricular outflow tract obstruction after the Valsalva maneuver.
:
CARDIAC CATH
Disease Progression
J Am Coll Cardiol. 2003;42(9):1693.
Sudden Cardiac Death
Most frequent in young adults <30-35 years old
Primary VF/VT Tend to die during or
just following vigorous physical activity
Often is 1st clinical manifestation of disease
HCM is most common cause of SCD among young competitive athletes
J Am Coll Cardiol. 2003;42(9):1693.
Complications
Heart Failure
– Only 10-15% progress to NYHA III-IV
Endocarditis
– 4-5% of HCM patients
– Usually mitral valve affected
Embolisation
Atrial Fibrillation
– Prevalent in up to 30% of older patients
– CO decreases by 40% if AF present
Autonomic Dysfunction
– 25% of HCM patients – Associated with poor
prognosis
COMPLICATIONS
31
TREATMENTGoals: – Ventricular
contractility
Myocardial depression
– Ventricular volume
Volume loading
– Ventricular compliance and outflow tract dimensions
– Pressure gradient across the LVOT
– Vasoconstriction
Medical therapy
Device therapy
Surgical
Alcohol septal ablation
Transplantation
DisopyramideVerapamil
Beta-blockers
If maximum dose failsIf maximum dose fails
PacingAblation
Myectomy
PacingAblation
Myectomy
Medical Therapy in HOCM
Goals Exercise-induced
gradient
Oxygen-demand
Prolong Diastolic Filling Period
33
How Beta blockers work?
Pressure gradient across LVOT
– Inotropic state of left ventricle.
– Diastolic dysfunction
– Lt. Ventricle compliance
HR
– Myocardial oxygen consumption
– Myocardial ischemia potential
CONTRAINDIACATION
Inotropic
Sympathomimetic
NitratesExcept in patients with CAD
Digitalis Except with uncontrolled A-fib.
Diuretics
Preload and ventricular volume
Outflow gradient
TREATMENT
Septal myectomy
Trans aortic / Left ventriculotomy
Extended septal myectomy
myectomy with Plication of Aml
Modified konno operation
Mitral valve replacement
SURGICAL MANAGEMENT
Surgical septal myectomy
•In patients that remain symptomatic despite maximal
medical therapy with
•SAM
• Septum thickness more than 18 mm
• Resting gradient more than 50 mmHg
• Provoked gradient more than 50 mmHg
. Occurrence of AF
. High risk for sudden death
• Asymptomatic younger patients with
. Gradient > 100 mmHg
. High risk of sudden death
TRANS AORTIC APPROACHMedian sternotomy/ CPB estsblished
Transverse aortotomy/ stay sutures
Right aortic cusp –retracted anteriorly
Narrow ribbon retractor-placed in LVOT
1st -Incision below right coronary cusp & parallel to LVOT
2nd parallel incision- as far leftward as possible- careful about MV
Both incision deepened –toward LV apex
Two parallel vertical incision connected by transverse incision.- rectangular piece of septum has been excised.
Patients with left anterolateral free wall hypertrophy- third incision below the commissure between left and right coronary cusp & directed towards base of anterolateral papillary muscle.
TRANS AORTIC APPROACH
TRANS AORTIC APPROACH
TRANS AORTIC APPROACH
This picture demonstrates the hypertrophied septum protruding into the left ventricular outflow tract. The leaflets of the aortic valve are pulled aside. Looking through the annulus, the anterior leaflet of the mitral valve is noted inferiorly, the bulging septum superiorly.
Opening of the outflow tract is much larger after the fibrious tissue has been removed, along with
muscle; that the chords of the anterior leaflet of the mitral valve are now visible
TRANS AORTIC APPROACH
Location & thickness
Adequacy of myectomy
Correction of MR
Identifying complications
Gradient/SAM/MR
IF residual gradient > 10 to 15 mm hg- additional muscle resection.
ADJUNCTS TO MYECTOMY-TEE
APICAL MYECTOMY Apical HCM /Midventricular obstruction
Incision in the apex of the left ventricle lateral to the LAD
Excision of the ventricular muscle at the apex and midventricular level is performed.
Objective- increasing LV end diastolic volume / Improve LV compliance
Post op – significant decrease in LV end diastolic pressure ,increase in LV diastolic volume index,increase in stroke volume.
Modified konno operation
Modified Konno Operation Localized subaortic stenosis or tunnel stenosis-when aortic annulus and valve are normal.
Transverse aortotomy.
RV opened –transverse incision- 2cm inferior to the level of pulmonary valve cusp.
Right angle clamp –passed from aortotomy through aortic valve –into left side of LVOT
Tip of the clamp palpated from septum-incision made through RV side-
Incision extended inferiorly about 1 cm parallel to LVOT – at an angle to RVOT.
Patch used to widen- LVOT
Extended myectomy with reconstruction of subvalvular apparatus -- Messmer
Septal myectomy extended into the LV cavity- wide toward the apex
Providing access to both the papillary muscle- mobilized down to the apex
All hypertrophied portions and muscle trabeculae are resected.
Mobilization of malpositioned papillary muscle- permits mitral leaflets to deflect from LVOT during systole
Myectomy with plication of AML -- McIntosh
Plication can be performed through the aortic valve.
Horizontal/vertical direction
Polypropylene sutures
ANTERIOR LEAFLET EXTENSION
Insertion of a pericardial patch.
Increases leaflet stiffness.
Causes lateral displacement of the secondary chordae tendinae.
Functions haemodynamically as a spinnakar sail to eliminate SAM.
MITRAL VALVE REPLACEMENT/REPAIR
Mitral valve replacement- Reserved for severely symptomatic individuals with gradient > 50 mmHg in special situations like
Thin septum < 18 mm
Small aortic annulus
Unusual morphology of septum
Inability to achieve adequate resection
Not amenable to repair- Myxomatous/ degenerative.
Residual or recurrent obstruction
Annuloplasty rings should be avoided to prevent SAM
If necessary – flexible or rigid bands on the posterior leaflet preferred.
Postoperative care
Maintain adequate preload- LA pressure of 16 to 18 mm hg may be required
Avoid digitalis & isoproterenol – increase residual outflow gradient
Avoid hypovolemia & NTG
AF is poorly tolerated - Use of amiodarone
Complications
Complete heart block (2.5% to 10 %) / LBBB (50%)
Perioperative MI
VSD (3%)
> if septal thickness < 18 mm
D/t iatrogenic / septal infarctionb
AR (5%)
Progressively increasing
Risk - Small aortic annulus (<21 mm),
Low mitral septal contact lesion
D/t iatrogenic/ loss of support to right cusp/ Hemodynamic
changes
LV aneurysm
0.5
0.6
0.7
0.8
0.9
1.0
0 2 4 6 8 10
Surgical Myectomy
I 1 30
II 2 24
III 48 7
IV 14 0
NYHA Pre Post
Obstructive
Obstructive Post-myectomy
Operative mortality 0.8%
Ommen S et al. J Am Coll Cardiol 2005
Operative mortality 0.8%
Gradient reduction 67 ----3
Post-op NYHA 1-2 94%
Hospital mortality 0- 6%5 yr survival 93-84%10 yr survival 88-71 %
Alcohol Septal Ablation
- performed percutaneously
- 100% alcohol is injected into a septal perforator
- results in infarction of the injected area
Successful short-term outcomesLVOT gradient reduced from a mean of 60-70 mmHg to <20 mmHg Symptomatic improvements, increased exercise tolerance
Long-term data not available yet
Complications spill over
Complete heart blockLarge myocardial infarctions
Ventricular arrhythmia & ECG changes
ALCOHOL SEPTAL ABLATION
Alcohol Septal Ablation
Before After
ALCOHOL SEPTAL ABLATION
Dual-Chamber Pacing
Proposed benefit: pacing the RV apex will
Decrease the outflow tract gradient
By – Decreased septal motion
Reduced SAM of the AML
Late activation of base of septum
Decreased LV contractility
used in patients with significant symptoms who would not tolerate surgical therapy
Objective measures such as exercise capacity and oxygen consumption are not improved
No correlation has been found between pacing and reduction of LVOT gradient
DUAL CHAMBER PACING
Dual-Chamber Pacing CARDIOVERTER – DEFIBRILLATOR
in combination with myectomy - pts. With history of cardiac arrest/ unexplained syncope.
CARDIAC TRANSPLANT
not responding to maximal medical/surgical theraphy
intractable heart failure with dilated ventricular cavities
LEFT VENTRICULAR- AORTIC CONDUIT
valved conduit from apex of LV to the thoracic or abdominal aorta
OTHER MEASURES
Ablation vs. Myectomy
0.9
1.3
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Myectomy Ablation
279 patientsProcedural Mortality (%)
71
7
75
15
0
10
20
30
40
50
60
70
80
Myectomy Ablation
Efficacy of Therapeutic Strategies
Nishimura et al. NEJM. 2004. 350(13):1323.
60 of 48
HCM vs. Athletic HeartHCM
Can be asymmetric
Wall thickness: > 15 mm
LA: > 40 mm
LVEDD : < 45 mm
Diastolic function: always abnormal
Athletic heart
Concentric & regresses
< 15 mm
< 40 mm
> 45 mm
Normal
Occurs in about 2% of elite althetes – typical sports, rowing, cycling, canoeing
Former athletes & weekend warriors do NOT develop athletic heart
Elite female athletes do NOT develop athletic heart
X ray
Cardiomegaly
LA enlargement
Small aorta
Pulmonary edema
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