presentation will give idea about HOCM(hypertrophic obstructive carxdiomyopathy).

1. HYPERTROPHIC
CARDIOMYOPATHY
DR. DHAVAL A. BHIMANI

2. DEFINATION
• Cardiomyopathies are defined by structural and functional abnormalities of the
ventricular myocardium that are unexplained by flowlimiting coronary artery
disease or abnormal loading conditions.
• It is genetic myocardial disorder characterized by left and/or right ventricular
hypertrophy that is usually, but not always, asymmetric and is associated with
microscopic evidence of myocardial fiber disarray and fibrosis.
• Degree of hypertrophy at any given site can vary substantially and influences
clinical manifestations of the disease.

3. • Ventricular septal hypertrophy is the most common type of asymmetric
hypertrophy, with midventricular, apical, and other types occurring much less
frequently.
• Forms interfering with left ventricular (LV) emptying, termed hypertrophic
obstructive cardiomyopathy (HOCM) or (obsolete) idiopathic hypertrophic
subaortic stenosis (IHSS), are of surgical importance and are characterized by a
variable dynamic obstruction that is usually subaortic and is associated with
abnormal systolic anterior motion (SAM) of the anterior leaflet of the mitral valve.
• Prevalence of HCM in the general population is about 1 in 500 (0.2%).

4. HISTORY
• Pathologic findings compatible with HOCM were described by two 19th-century
French pathologists, Hallopeau and Liouiville and an early 20th-century German
pathologist, Schmincke.
• In 1952, Davies described a family from Cardiff, Wales, with five of nine siblings
affected and three dying suddenly who probably had this disease.
• Disease was first accurately categorized by Teare, a London pathologist, in
1958.Teare described both disproportionate thickening of the ventricular septum
compared with the free wall and presence of myocardial fiber disarray in young
people who died suddenly.

5. • To distinguish it from other cardiomyopathies, Goodwin and colleagues named
it hypertrophic obstructive cardiomyopathy, whereas Braunwald and colleagues
called it idiopathic hypertrophic subaortic stenosis and Wigle and colleagues,
muscular subaortic stenosis.
• At that time, LV outflow tract obstruction was thought to be distinctive for the
disease. That the anterior mitral leaflet contributed to the obstruction was first
documented in 1964 by Fix and colleagues and SAM of the mitral valve was
subsequently demonstrated angiographically.

6. ETIOLOGY
• Sarcomere protein gene mutations
• Metabolic disorders
• Mitochondrial cardiomyopathies
• Neuromuscular disease
• Malformation syndromes
• Infiltrative disease/inflammation
• Endocrine disorders
• Drugs

7. • In up to 60% of adolescents and adults with HCM, the disease is an autosomal
dominant trait caused by mutations in cardiac sarcomere protein genes.
• Five to ten percent of adult cases are caused by other genetic disorders including
inherited metabolic and neuromuscular diseases, chromosome abnormalities and
genetic syndromes.
• Some patients have non-genetic disorders that mimic genetic forms of the
disease, for example, senile (TTR) and (AL) amyloidosis

9. TYPES

10. PATGHOPHYSIOLOGY
• LVOT Obstruction
• Diastolic Dysfunction
• Myocardial Ischemia
• Autonomic Dysfunction
• Mitral Regurgitation

11. LVOT OBSTUCTION
• Obstruction causes an increase in LV systolic pressure, which leads to a complex
interplay of abnormalities including prolongation of ventricular relaxation, elevation of
LV diastolic pressure, mitral regurgitation, myocardial ischemia, and a decrease in
forward cardiac output.
• Outflow obstruction usually occurs in HCM by virtue of mitral valve SAM and mitral-
septal contact. Although the mechanism of the outflow tract gradient in HCM was
initially thought to be caused by systolic contraction of the hypertrophied basal
ventricular septum encroaching on the LVOT, most recent studies emphasize that
during ventricular systole, flow against the abnormally positioned mitral valve
apparatus results in drag force on a portion of the mitral valve leaflets, which pushes
the leaflets into the outflow tract

12. • Patients may have little or no obstruction of the LVOT at rest but can generate
large LVOT gradients under conditions such as exercise, the strain phase of the
Valsalva maneuver, or during pharmacologic provocation.
• There is often large spontaneous variation in the severity of the gradient during
day-to-day activities or even with food or alcohol intake, exacerbation of
symptoms during the postprandial period is common.

14. DIASTOLIC DYSFUNCTION
• Diastolic dysfunction arising from multiple factors is a major pathophysiologic
abnormality in HCM that ultimately affects both ventricular relaxation and
chamber stiffness.
• Diffuse myocardial ischemia may further affect both relaxation and chamber
stiffness. A compensatory increase in the contribution of late diastolic filling
during atrial systole is associated with these alterations.
• With exercise or any other type of catecholamine stimulation, the decrease in
diastolic filling period as well as myocardial ischemia will further lead to severe
abnormalities of diastolic filling of the heart, with chest pain and/or an increase in
pulmonary venous pressure causing dyspnea.

15. MYOCARDIAL ISCHEMIA
• The myocardial ischemia is frequently unrelated to the atherosclerotic epicardial
coronary artery disease (CAD) but is caused by supply– demand mismatch.
• Patients with HCM of any age have increased oxygen demand caused by the
hypertrophy and adverse loading conditions. They also have compromised
coronary blood flow to the LV myocardium because of intramural arterioles with
thickened walls attributable to medial hypertrophy associated with luminal
narrowing.

16. AUTONOMIC DYSFUNCTION
• During exercise, approximately 25% of patients with HCM have an abnormal blood
pressure response defined by either a failure of systolic blood pressure to rise 20 mm
Hg or a fall in systolic blood pressure.
• The presence of this finding is associated with a poorer prognosis.
• This inability to augment and sustain systolic blood pressure during exercise is caused
by either the dynamic LVOT obstruction or systemic vasodilatation during exercise.
• It is speculated that autonomic dysregulation88 is present in patients with HCM and
that the fall in blood pressure associated with bradycardia may be an abnormal reflex
response to obstruction

17. MITRAL REGURGITATION
• Mitral regurgitation is common in patients with LVOT obstruction and may play a
primary role in producing symptoms of dyspnea.
• The temporal sequence of events of eject-obstruct-leak supports the concept that
the mitral regurgitation in most patients is a secondary phenomenon.
• The mitral regurgitation is usually caused by the distortion of the mitral valve
apparatus from the SAM secondary to the LVOT obstruction.
• Changes in ventricular load and contractility that affect the severity of outflow
tract obstruction similarly affect the degree of mitral regurgitation.

18. DIAGNOSIS
• The diagnosis of HCM rests on the detection of increased LV wall thickness by any
imaging modality, but the disease phenotype also includes myocardial fibrosis,
morphologic abnormalities of the mitral valve apparatus, abnormal coronary
microcirculatory function and electrocardiographic abnormalities.
• Due to the diverse aetiology of the disease, detection of increased LV wall
thickness that is unexplained by loading conditions should prompt a systematic
search for its underlying cause.

19. IN ADULTS
• In an adult, HCM is defined by a wall thickness ≥15 mm in one or more LV
myocardial segments—as measured by any imaging technique
(echocardiography, cardiac magnetic resonance imaging (CMR) or computed
tomography (CT))—that is not explained solely by loading conditions.
• Genetic and non-genetic disorders can present with lesser degrees of wall
thickening (13–14 mm); in these cases, the diagnosis of HCM requires evaluation
of other features including family history, non-cardiac symptoms and signs,
electrocardiogram (ECG) abnormalities, laboratory tests and multi-modality
cardiac imaging.

20. IN CHILDREN
• increased LV wall thickness is defined as the thickness more than 2 standard
deviations above the mean for age, sex, or body size (z score >2).
• These morphometric distinctions are not rigid, however, as patients have now
been identified who are "genotype positive/phenotype negative" and may be
considered to have subclinical HCM.

21. IN RELATIVES
• The clinical diagnosis of HCM in first-degree relatives of patients with
unequivocal disease (LVH ≥15 mm) is based on the presence of otherwise
unexplained increased LV wall thickness ≥13 mm in one or more LV myocardial
segments, as measured using any cardiac imaging technique [echocardiography,
cardiac magnetic resonance (CMR) or CT].
• In families with genetic forms of HCM, mutation carriers can have non-diagnostic
morphological abnormalities that are sometimes associated with abnormal ECG
findings.
• In general, the presence of any abnormality [for example, abnormal Doppler
myocardial imaging and strain, incomplete systolic anterior motion (SAM)
orelongation of the mitral valve leaflet(s) and abnormal papillary muscles],
particularly in the presence of an abnormal ECG, increases the probability of

22. CLINICAL PRESENTATION AND NATURAL HISTORY
• Many patients with HCM are asymptomatic, but most who come to surgical
attention will have limiting symptoms.
• Typical symptoms caused by obstructive HCM are exertional dyspnea, chest pain
(angina), and/ or lightheadedness, especially lightheadedness is associated with
rapid change in posture, or syncope.
• Most common clinical scenario for patients referred for septal myectomy is the
development of symptoms in the fourth, fifth, or sixth decade of life.

23. • It seems likely, however, that in most patients, the development of symptoms
corresponds to the development of subaortic obstruction.
• Occurrence of AF can also precipitate symptoms and predispose to systemic
embolism, which occurs in 6% of patients. AF is found in 30% of older patients with
HCM.
• It is interesting to note that approximately one-third of patients with HCM who are
symptomatic will have exacerbation of symptoms, predominantly dyspnea or
presyncope, after meals.
• Postprandial symptom exacerbation is associated with higher resting LVOT gradients
and advanced clinical symptoms.

24. • In the general population, survival of patients with HCM is similar to survival of
individuals without disease, and high mortality in HCM in earlier reports is likely
due to excess numbers of high-risk patients included in studies from tertiary
referral centers.
• The importance of LVOT obstruction with regard to late outcome of patients with
HCM has been controversial, but there is now substantial evidence that survival of
HCM patients with outflow obstruction is reduced in comparison to patients
without obstruction.

25. • Studies by Maron et al., Au tore and associates, and Elliot and coworkers have
demonstrated convincingly a strong correlation between resting outflow
gradients and late risk of death. In a longitudinal follow-up of 1,101 patients with
HCM, Maron et al. reported that patients with outflow tract obstruction (a basal
gradient of at least 30 mmHg) had a risk of death from HCM or symptom
progression that was more than four times that observed among patients without
obstruction
• Of note, patients with obstruction and mild symptoms (NYHA class II) were more
likely to have progression to severe symptoms or to die from heart failure than
asymptomatic patients with cardiomyopathy.

26. GUIDELINES FOR INVESTIGATION
• ECG- resting and ambulatory.
• The standard 12-lead ECG can be normal at presentation (6% of patients in referral
cohort studies) but generally shows a variable combination of LVH, ST- and T-wave
abnormalities, and pathological Q-waves.
• When interpreted in conjunction with findings on echocardiography and CMR
imaging, features that would normally indicate other conditions, such as myocardial
ischaemia or infarction, can—with age at diagnosis, inheritance pattern and associated
clinical features—suggest an underlying diagnosis or provide clues to the distribution
of hypertrophy and myocardial scar.

28. ECHOCARDIOGRAPHY
• Echocardiography is central to the diagnosis and monitoring of HCM.
• In most patients, hypertrophy preferentially involves the interventricular septum
in the basal LV segments but often extends into the lateral wall, the posterior
septum and LV apex.
• Useful for assessing
• left ventricular wall thickness.
• Associated abnormalities of the mitral valve and left ventricular outflow tract.
• Assessment of latent obstruction.
• Left atrial enlargement
• Assessment of diastolic function & Systolic function

30. VARIANTS
• Stress echocardiography
• Contrast echocardiography
• Tranesophageal echocardiography

34. CARDIOVASCULAR MAGNETIC RESONANCE
IMAGING
• Assessment of ventricular morphology and function.
• Myocardial fibrosis.
• Late Gadolinium Enhancement and Prognosis.
• the extent of Lsupport the use of LGE GE on CMR has some utility in predicting
cardiovascular mortality, but current data do not in prediction of SCD risk.
• Differential diagnosis

36. NUCLEAR SCINTIGRAPHY & CT SCAN

37. ENDOMYOCARDIAL BIOPSY

38. LABORATORY TEST
• First-line laboratory screening should include haematology, glucose, cardiac
enzymes (creatine kinase, aspartate aminotransferase, alanine aminotransferase,
lactate dehydrogenase), renal and liver function tests, pH, electrolytes and uric
acid.
• Following specialist evaluation, additional tests are often required, including
measurement of lactate, pyruvate, ammonia, ketones, free fatty acids, carnitine
profile, urine organic acids and amino acids.

40. GENETIC TESTING AND FAMILY SCREENING
• In the majority of cases, HCM is inherited as an autosomal dominant genetic trait
with a 50% risk of transmission to offspring.
• Some cases are explained by de novo mutations, but apparently sporadic cases
can arise because of incomplete penetrance in a parent and, less commonly,
autosomalrecessiveinheritance.
• In patients fulfilling HCM diagnostic criteria, sequencing of sarcomere protein
genes identifies a disease-causing mutation in up to 60% of cases.

49. TREATMENT
• Medical management of associated symptom and complication, along with LVOT
obstruction.
• Interventional management.
• Surgical management

50. MEDICAL MANAGEMENT
• Ifasymptomatic, —Recommendations
• Class I = For patients with HCM, it is recommended that comorbidities that may
contribute to cardiovascular disease (eg, hypertension, diabetes, hyperlipidemia,
obesity) be treated in compliance with relevant existing guidelines, (Level of
Evidence: C)
• Class IIa = Low-intensity aerobic exercise is reasonable as part of a healthy lifestyle for
patients with HCM. (Level of Evidence: C)
• Class IIb = The usefulness of beta blockade and calcium channel blockers to alter
clinical outcome is not well established for the management of asymptomatic patients
with HCM with or without obstruction. (Level of Evidence: C)

51. • Class III: Harm
• 1. Septal reduction therapy should not be performed for asymptomatic adult and pediatric
patients with HCM with normal effort tolerance regardless of the severity of obstruction.
(Level of Evidence: C)
• 2. In patients with HCM with resting or provocable outflow tract obstruction, regardless of
symptom status, pure vasodilators and high-dose diuretics are potentially harmful.
(Level of Evidence: C)

56. INTERVENTIONAL MANAGEMENT
• Involves surgical myectomy and septal alcohol ablation.
• Dual chamber pacing.
• Cardiac transplantation.

62. SEPTAL MYECTOMY
• standard median sternotomy.
• normothermic cardiopulmonary bypass using a single, two-staged venous
cannula and cold blood cardioplegia (initial dose of 1,000 to 1,200 ml) for
myocardial protection,
• Pericardial sutures are used only on the right side to elevate pericardium toward
the surgeon and allow the left ventricle to fall posteriorly in the thorax.
• Oblique aortotomy is made slightly closer to the sinotubular ridge than is usual
for aortic valve replacement, and the incision is carried through the midpoint of
the noncoronary aortic sinus of Valsalva to a level approximately 1 cm above the
valve annulus.

64. • A cardiotomy sucker is placed through the aortic valve and used to depress the
anterior leaflet of the mitral valve and protect it from injury.
• A sponge stick is used to depress the right ventricle and rotate the septum
posteriorly, orienting the LV outflow anteriorly.
• A standard No.10 scalpel blade is used for incision in the septum that begins just
to the right of the nadir of the right aortic sinus.

66. • The area of septal excision is then deepened and lengthened toward the apex of the
heart being certain to excise hypertrophied septum beyond endocardial scar.
• Adequate septal myectomy usually yields 3 to 12 g of muscle. The use of the sponge
stick to depress the heart posteriorly will improve exposure of the distal extent of the
myectomy.
• Mitral valve replacement is reserved for patients with intrinsic leaflet abnormalities
that cannot be repaired.
• To confirm complete relief of the LVOT obstruction, we can measure simultaneous
aortic and LV pressure by direct needle puncture before and after myectomy.

67. • If the resting LVOT gradient is diminished by the effects of anesthesia, premature
ventricular beats are induced by stimulating the ventricle to elicit the dynamic
gradient produced by the Brockenbrough phenomenon; the postextrasystolic
contraction is more forceful due to increased contractility and decreased afterload.
• The same maneuver is then repeated after myectomy.
• In some patients, it is necessary to provoke LVOT gradient during surgery with
isoproterenol.
• Intraoperative TEE can identify residual MR, SAM, and any septal defects created by
excision of septal muscle.

68. • Severe MR in patients with obstructive HCM is not an indication for mitral valve
replacement. Indeed, MR due to SAM is always relieved when outflow tract
obstruction is corrected.
• Unroofing of coronary artery bridging is performed in selected cases, particularly
in young patients and those who have angina preoperatively

69. COMPLICATION
• Complete heart block
• Iatrogenic ventricular perforation
• Complete left bundle branch(most common after septectomy)
• Alcohol septal ablation causes right bundle branch block in up to 60% of patients,
and in patients who have had previous alcohol septa! ablation, the risk of
pacemaker insertion following surgical myectomy was 36% compared with 3% for
those without prior intervention.
• Aortic valve regurgitation

70. SPECIAL CONSIDERATION
• There is general consensus that an ICD is strongly warranted for secondary
prevention of SCD in patients with prior cardiac arrest or sustained and
spontaneously occurring ventricular tachycardia, and should be considered for
primary prevention in patients with multiple clinical risk factors and in selected
patients with a single major risk factor such as a history of SCD in a close relative.
• For patients who need an ICD and are referred for septal myectomy, we can
prefer to delay device implantation until the third or fourth day postoperatively
and avoid the potential for lead dislocation if the ICD is placed immediately
preoperatively.

71. CARDIOVERTER-DEFIBRILLATOR
• Patients with HOCM and unexplained syncope, cardiac arrest, and ventricular
tachycardia or fibrillation should be considered for implantation of a cardioverter-
defibrillator in combination with myectomy or other surgical procedures.
• Implantation may be indicated in some patients with nonobstructive HCM who
have a history of cardiac arrest or unexplained syncope and in whom physiologic
testing is positive

73. DUAL-CHAMBER PACING
• Dual-chamber (DDD) pacing decreases the subaortic pressure gradient and relieves
associated symptoms in some patients with HOCM.
• sociated symptoms in some patients with HOCM. The mechanism by which the
gradient is decreased is uncertain but may be related to decreased septal motion,
which results in increased LV outflow tract area and reduced SAM of the anterior
mitral leaflet, late activation of the basal septum, or decreased LV contractility.
• Not all patients respond favorably to pacing.
• In the study by Topilski and colleagues, positive results were attributed to periodic
assessment and optimization of pacemaker function. DDD pacing may be of particular
value in the elderly and other patients who are not candidates for myectomy or septal
ablation

75. CARDIAC
TRANSPLANTATION
• Cardiac transplantation should
be considered for suitable
candidates with HOCM who have
not responded to maximal
medical and surgical therapy.
• These patients usually have
intractable symptoms of heart
failure associated with dilated
ventricular cavities

76. LEFT VENTRICULAR–AORTIC CONDUIT
• A valved conduit from the apex of the LV to the thoracic or abdominal aorta has
been inserted in patients with HOCM.
• This procedure should be used only when other methods of surgical treatment
are infeasible.

78. THANK YOU