CARDIOLOGY

1. HCM

2. GENETICS
• HCM is transmitted as a mendelian trait with an autosomal
dominant pattern of inheritance
• every offspring of an affected relative has a 50% chance of
developing the disease.
• HCM is now known to be caused by mutations in 11 or
more genes encoding proteins of the thick and thin
contractile myofilament components of the cardiac
sarcomere or the adjacent z disc
• Two sarcomere genes, those encoding β-myosin heavy
chain (MYH7) and myosin-binding protein C (MYBPC3),
are by far the most common, accounting for 30% of
consecutively screened patients with HCM and 70% of
those successfully genotyped.
• The troponin T gene (TNNT2) and several others are each
responsible for up to 5% of cases

3. ROLE OF GENETIC TESTING
• Rapidly automated DNA sequencing now provides opportunities for
comprehensive commercially available genetic testing
• To date, the greatest power of molecular testing currently lies with the
capability to identify or exclude affected status in family members without LV
hypertrophy
• Genetic testing can, however, clarify diagnosis for patients with metabolic and
storage disorders in which clinical presentation and pattern of LV hypertrophy
mimic those in sarcomeric HCM, but in which pathophysiology, natural history,
and management are dissimilar, including Fabry disease, PRKAG2, and LAMP2
(Danon’s disease).
• LAMP2 cardiomyopathy is associated with a lethal natural history refractory to
defibrillation therapy (with survival uncommon beyond 25 years), necessitating
early recognition and heart transplantation,
• whereas enzyme replacement therapy is available for patients with Fabry
disease.

4. VARIENTS
• Typically, one or more regions of LV chamber are
of greater thickness than other areas, often with
sharp transition in thickness between adjacent
areas or noncontiguous patterns of segmental
hypertrophy
• extension into the right ventricle in some patients.
• No single morphologic form of HCM is considered
“classic” or typical, and none are consistently
related to outcome.

5. TIME OF PHENOTYPIC AFFECTION
• LV hypertrophy may evolve in a dynamic fashion.
• Usually, the HCM phenotype remains incomplete until adolescence,
when accelerated growth and maturation are accompanied by
spontaneous (often striking) increases in LV wall thickness and more
extensive distribution of hypertrophy.
• These structural changes may occasionally be delayed until mid-life or
even later (late-onset adult LV hypertrophy)
• Genetically affected family members without LV hypertrophy (gene-
positive, phenotype-negative, reflecting incomplete penetrance)may
show ancillary signs of disease:
1. Subclinical diastolic dysfunction,
2. blood-filled myocardial crypts
3. mitral leaflet elongation
4. collagen biomarkers and
5. myocardial scarring or
6. 12-lead ECG abnormalities that may precede the appearance of LV
hypertrophy.

6. Mitral Valve Apparatus
• Primary structural abnormalities of the mitral
apparatus responsible for LV outflow obstruction
are part of HCM phenotypic expression
1. The mitral valve may be more than twice
normal size as a consequence of elongation of
both leaflets, or segmental enlargement of only
the anterior leaflet or mid-scallop of the
posterior leaflet.
2. congenital and anomalous anterolateral
papillary muscle insertion directly into anterior
mitral leaflet (without interposition of chordae
tendineae) may occur.

7. Histopathology
• In HCM, hypertrophied cardiac muscle cells
(myocytes) in both ventricular septum and LV free
wall exhibit bizarre shapes, often maintaining
intercellular connections with several adjacent cells.
• Many myocytes (and also myofilaments) are
arranged in chaotic and disorganized architectural
patterns .
• Areas of cell disarray are evident in 95% of HCM
hearts at autopsy, usually occupying substantial
portions of hypertrophied (as well as
nonhypertrophied) LV myocardium (i.e., 33% of
septum and 25% of free wall).

8. Histopathology
• At autopsy, the vast majority of patients with HCM
exhibit intramural coronary arterioles with marked
thickening of the vessel wall secondary to smooth
muscle hyperplasia in the media (associated with
abundant disorganized elastic fibers), causing
deformation and narrowing of the lumen and
frequently located within or close to areas of
myocardial scarring.
• This microvascular small-vessel disease probably is
responsible for repeated bursts of clinically silent
myocardial ischemia leading to myocyte death, with a
repair process in the form of replacement (and often
transmural) myocardial fibrosis
• In addition, volume of the interstitial (matrix) collagen
compartment, constituting the structural LV
framework, is greatly expanded.

9. Consequence(PATHOPHYSIOLOGY OF VT IN HCM)
• It is likely that the interplay of disorganized
cellular architecture, microvascular ischemia,
and replacement fibrosis impairs transmission of
electrophysiologic impulses and predisposes to
disordered patterns and increased dispersion of
electrical depolarization and repolarization.
• This, in turn, serves as an electrophysiologically
unstable substrate and a trigger for REENTRY
VENTRICULAR ARRTHMIAS

10. PATHOPHYSIOLOGY
• LVOTO
• DIASTOLIC DYSFUNCTION
• MICROVASCULAR DYSFUNC

11. Pathophysiology LVOTO
• SUB AORTIC OBSTRUCTION IN HCM represents true mechanical
impedance to LV outflow, producing markedly increased intraventricular
pressures that over time may be detrimental to LV function, probably by
increasing myocardial wall stress and oxygen demand .
• In the vast majority of patients, obstruction is produced in the proximal
LV BY SYSTOLIC ANTERIOR MOTION (SAM) of the mitral valve in which
elongated leaflets bend sharply at 90 degrees and contact the septum
in midsystole owing to a drag effect—that is, hydrodynamic pushing
force of flow directly on the leaflets
• The MAGNITUDE OF THE OUTFLOW GRADIENT, which is reliably
estimated with continuous wave Doppler, is directly related to the
duration of mitral valve–septal contact.
• Mitral regurgitation is a secondary consequence of SAM, with the jet
(usually mild to moderate in degree) directed posteriorly
• Occasionally, intraventricular obstruction may occur at mid-cavity level
caused by systolic contact of septum with a papillary muscle that is
anomalously positioned and may insert directly into anterior mitral
leaflet This form of obstruction may be associated with LV apical
aneurysm.

12. PATHOPHYSIOLOGY OF MR
• Mitral regurgitation is a secondary
consequence of SAM, with the jet (usually
mild to moderate in degree) directed
posteriorly
• Marked and centrally located mitral
regurgitation jets usually suggest an intrinsic
valve abnormality (e.g., with myxomatous
degeneration).

13. DIASTOLIC DYS(CAUSES)
• Reduced ventricular compliance in HCM
probably results largely from those factors
determining passive elastic properties of the
LV
1. hypertrophy,
2. replacement scarring,
3. Interstitial fibrosis, and
4. disorganized cellular architecture.

14. Microvascular Dysfunction
• Myocardial ischemia due to microvascular dysfunction
appears to be an important pathophysiologic component of
the HCM disease process, promoting adverse LV
remodeling and ultimately affecting clinical course.
• Marked reduction in coronary reserve can be
demonstrated in patients with HCM using positron
emission tomography (PET) early in the clinical course (in
both hypertrophied and nonhypertrophied regions of the
left ventricle) and is an important determinant of
prognosis, including progressive heart failure, systolic
dysfunction, and long-term cardiovascular mortality.
• PET represents the technique of choice for the assessment
of microvascular function in patients with HCM, although
its systematic use has not entered clinical practice
systematically

15. PRINCIPAL DETERMINANTS OF PROGRESSIVE
HEART FAILURE
• The principal determinants of progressive heart failure and
heart failure–related death in HCM are
1. LV outflow obstruction,
2. atrial fibrillation, and
3. diastolic dysfunction,
4. SCARRING DUE TO MICROVASULAR ISCHEMIA
• each alone or in combination.
• However, in contrast with sudden death risk (which is
related to particularly marked LV hypertrophy),
• greater LV wall thickness ----is not associated with an
increased likelihood of progressive heart failure
symptoms.

16. HF IN HCM
• Approximately 3% of patients with HCM develop advanced
(endstage) heart failure associated with systolic dysfunction
(ejection fraction <50%), a consequence of
1. small vessel–mediated myocardial ischemia and
2. diffuse transmural scarring,
MOST RELIABLE RISK MARKER FOR EVOLUTION TO THE END STAGE is
in fact a family history of HCM with systolic dysfunction.
• This profound form of heart failure is associated with LV remodeling
including wall thinning, chamber enlargement, or both, as well as
with atrial fibrillation.
• The end stage, with unrelenting heart failure symptoms, is
virtually the sole indication for heart transplantation in
• Survival after transplantation in HCM is similar to (or possibly more
favorable than) that in other cardiac diseases (75% at 5 years, 60%
at 10 years

17. Sudden death in HCM
• Sudden death in HCM may occur at a wide range
of ages, most commonly in adolescents and
young adults before the age of 30 to 35 years.
• the potential for lethal ventricular
tachyarrhythmias is mitigated at more advanced
ages (even in the presence of conventional risk
markers)
• Indeed, in older patients, morbidity and
mortality is largely unrelated to HCM, and more
frequently the consequence of other cardiac or
noncardiac comorbid diseases.

18. RISK MARKERS FOR PRIMARY
PREVENTION(PRPHYLACTIC ICD)
risk markers include one or more of the following, which
assume greater weight in younger patients (<50 years of age)
• (1) family history of one or more premature HCM-related
deaths, particularly if sudden and multiple;
• (2) unexplained syncope, especially if recent;
• (3) hypotensive or attenuated blood pressure response to
exercise;
• (4) multiple, repetitive (or prolonged) nonsustained bursts
of ventricular tachycardia on serial ambulatory ECGs;
• (5) massive LV hypertrophy (wall thickness, ≥30 mm)
EXTENSIVE LATE GADOLINIUM ENHANCEMENT ON
CONTRAST CMR imaging (occupying 15% or more of LV mass)
has been shown to be an independent predictor of sudden
death, even in the absence of conventional risk factors,
leading to consideration of prophylactic ICDs

22. OTHER RISK FACTORS
1. THIN-WALLED AKINETIC LV APICAL ANEURYSMS WITH
REGIONAL MYOCARDIAL SCARRING
2. COEXISTENT OBSTRUCTIVE ATHEROSCLEROTIC CORONARY
ARTERY DISEASE, (CAD)
3. MARKED LV OUTFLOW OBSTRUCTION AT REST,(LVOTO)
4. END-STAGE PHASE (AS A BRIDGE TO HEART
TRANSPLANTATION),
5. PERCUTANEOUS ALCOHOL SEPTAL ABLATION WITH
TRANSMURAL INFARCTION IN SELECTED PATIENTS
6. MULTIPLE SARCOMERE MUTATION
7. AS WELL AS EXTENSIVE LATE GADOLINIUM ENHANCEMENT
prognosis appears to be benign in gene carriers without LV
hypertrophy, with little evidence to justify disqualification of such
family members from most competitive sports or employment
opportunities, or prophylactic ICDs

24. Clinical parameters that favor the diagnosis of HCM in
trained athletes
1. Identification of a disease-causing sarcomeric
protein mutation
2. recognition of HCM in a relative;
3. transmitral Doppler waveform consistent with
altered LV relaxation and filling (DIASTOLIC
DYSFUNCTION)
4. LV END-DIASTOLIC CAVITY dimension less than
45 mm
5. LATE GADOLINIUM ENHANCEMENT on CMR
imaging.
6. NO REGRESSION OF LVH WITH DECONDITIONING

25. SCREENING IN FAMILY
• Screening evaluations usually are performed on a 12- to 18-month basis,
beginning at the age of 12 years.
• If these studies do not show LV hypertrophy by the time full growth is
achieved (at 18 to 21 years of age), it is likely that an HCM-causing
mutation is absent.
• However, morphologic conversion to the HCM phenotype (i.e., with LV
hypertrophy) can be delayed well into adulthood. Therefore it is not
possible to provide complete reassurance that a normal echocardiogram
at maturity unequivocally defines genetically unaffected status.
• In selected clinical circumstances, it may be prudent to extend
echocardiographic surveillance into adulthood at 5-year intervals, or to
pursue definitive genetic testing.
• When a mutation regarded as pathogenic has been identified in the
proband………. the absence of this mutation may exclude a relative from
further clinical evaluations. However, this strategy is not advisable in the
presence of variants of unknown significance.

27. Bacterial endocarditis PROPHYLAXIS
IN HOCM
• Bacterial endocarditis is an uncommon but profound
complication of HCM (prevalence <1%) and is almost
always confined to patients with LV outflow
obstruction.
• Vegetations most commonly involve
1. anterior mitral leaflet or
2. septal endocardium at the site of mitral valve contact.
 Prevention of bacterial endocarditis by antimicrobial
prophylaxis remains a prudent strategy before dental
or surgical procedures, particularly for patients with
HCM associated with outflow obstruction

28. INDICATION OF SURGERY
1. Patients with resting or provocable gradients
greater than 50 mm Hg
2. who continue to experience significant
functional limitation (i.e., NYHA class III-IV)
due to limiting symptoms of exertional
dyspnea, chest pain, or recurrent syncope
despite maximal medical therapy
may be considered candidates for surgical
therapy

29. Surgical therapy is not currently
recommended
1. for patients who are without significant outflow
tract obstruction,
2. for those who have relatively mild symptoms
with obstruction,
3. to treat associated complications of this
condition (e.g., AF, syncope)

30. SEPTAL MYETOMY-MORROW PROCEDURE
• The “gold standard” septal myectomy, described by
Morrow, is performed via an aortotomy so that the
proximal septum is approachable via the aortic valve.
• Between 5 to 15 g of myocardial tissue is resected, from
the base of the aortic valve to a region distal to the mitral
leaflets, such that the area of mitral-septal contact that
results in SAM is removed and the LVOT is enlarged.
• Because it is of critical importance to correctly identify the
involved portion of the ventricular septum and to resect
enough myocardium to relieve the outflow tract gradient,
most experienced centers employ transesophageal
echocardiography (TEE) to assist in localizing the desired
region for resection and to monitor the effect of resection
on the gradient intraoperatively.

31. ALTERATION IN THE CLASSIC MORROW PROCEDURE
• in which an extended myectomy is combined with
• partial excision and mobilization of the papillary
muscles,
which results in amelioration of the outflow tract
obstruction,
reduced tethering of the subvalvular mitral
structures
a more individualized surgical resection
depending on the extent and location of the
patient’s LVH. .

32. PATIENTS WITH SPECIFIC COMORBIDITIES
• In patients with specific comorbidities, such as
AF or coronary artery disease, myectomy may
be combined with adjunctive surgical
procedures such as the
maze procedure to treat AF or
coronary bypass grafting

33. Mitral valvular abnormalities IN HCM
• Mitral valvular abnormalities, such as elongated and
flexible leaflets, substantially contribute to the degree
of outflow tract obstruction in an important minority
of patients.
• These patients often benefit from mitral valve
plication at the time of myectomy to more effectively
reduce the degree of outflow tract obstruction that
results from SAM and to reduce the associated mitral
regurgitation.
• Mitral valve replacement is typically reserved for
patients
with significant primary valvular abnormalities such as
myxomatous degeneration leading to mitral valve
prolapse or regurgitation

34. COMPLICATION
• The modern-day septal myectomy procedure
carries a relatively low operative risk due to
continued technical refinement, with a
• cumulative operative mortality rate of
approximately 1% to 3% overall
• Left bundle branch block (LBBB) after myectomy
is understandably very common because of the
location of the procedure.
• Complete heart block requiring implantation of a
permanent pacemaker
• iatrogenic formation of a ventricular septal defect

35. SURGERIES IN HCM
• MORROWS EXTENDED MYECTOMY(MYECTOMY
WITH MV PLICATION)
• PAPILLARY MUSCLE REPAIR
• MV REPAIR OR REPLACEMENT
• MAZE PROCEDURE
• ALONG WITH CABG

36. SEPTAL ABLATION INDICATION (PT SELECTION CRITERIA)
1.Severe heart failure symptoms (i.e., NYHA class III-IV) despite maximal
medical therapy
2.Septal thickness >18 mm
3.Subaortic gradient >50 mm Hg (resting or with provocation) due to mitral-
septal contact
4.Absence of papillary muscle or mitral valvular anomalies (i.e., anomalous
papillary muscle insertion)
5.Absence of significant coronary arterial disease
6.Compatible septal perforator branch arterial anatomy
7.Relative contraindications to surgical myectomy (i.e., age, comorbidity)*

37. SEARCH FOR ABNORMALITIES THAT ARE BETTER ADDRESSED
SURGICALLY
• Such abnormalities include -
anomalous papillary muscle insertion into the mitral valve,
anatomically abnormal mitral valve with a long
anteroposterior leaflet,
coexistent coronary artery disease,
primary valvular disease (aortic or mitral),
subaortic membrane or pannus, none of which would be
adequately addressed by septal ablation.
 Abnormally elongated and flexible anterior mitral leaflets
resulting in an anterior location of the coaptation line and
outflow tract obstruction also are not correctable via
catheter-based techniques and require surgical myectomy
with plication.
 In addition, many experienced centers refer patients with a
septal thickness greater than 2.5 cm for surgical correction.

38. INVASIVE CONFIRMATION OF SIGNIFICANT LVOT
GRADIENT(TECHNIQUE)
• Given the fact that most cases of HOCM are diagnosed
noninvasively with echocardiography and, often, no invasive
hemodynamic studies have been performed before ablation,
• many operators reconfirm the presence of significant LVOT
obstruction by positioning an end-hole catheter in the
ventricular apex and recording a slow pullback under
fluoroscopic guidance.
• Alternatively, simultaneous measurement of the ascending
aortic and intracavitary pressures may be obtained via the
placement of an ascending aortic catheter and an end-hole
catheter as described earlier.
• If an LVOT gradient is not confirmed under basal or resting
conditions, provocation with amyl nitrate or the Valsalva
maneuver may be attempted.
• Failure to confirm a significant gradient after these maneuvers
should prompt the operator to further pursue alternative
etiologies for the patient’s symptom complex.

39. • A visual assessment of the contour
of the aortic (Ao) and left ventricular
(LV) pressures is important during
cardiac catheterization.
• Left, Patients with fixed obstruction
(either valvular stenosis or fixed
subvalvular stenosis) will
demonstrate a parvus and a tardus
in the upstroke of the aortic
pressure, beginning at the time of
aortic valve opening.
• Right, In patients with a dynamic
obstruction (such as that found in
hypertrophic cardiomyopathy), the
aortic pressure will rise rapidly at
the onset of aortic valve opening
and then develop a spike-and-dome
contour as the obstruction occurs in
late systole. The left ventricular
pressure also has a late peak
because of the mechanism of this
dynamic obstruction. LA indicates
left atrium.

40. • Response of the aortic pressure
after a long pause is useful in
differentiating between the fixed
obstruction of valvular aortic
(Ao) stenosis and the dynamic
obstruction of hypertrophic
cardiomyopathy.
• A, In this patient with valvular
aortic stenosis, the beat after the
premature ventricular contraction
(PVC) has an increase in pulse
pressure (P-P).
• B, In this patient with
hypertrophic cardiomyopathy,
there is a reduction in the pulse
pressure on the beat after the
premature ventricular
contraction. LV indicates left
ventricle; LA, left atrium.

41. Patients with hypertrophic cardiomyopathy
may have labile left ventricular (LV) outflow
tract gradients.
If septal reduction therapy is to be
considered, there must a gradient of >50
mm Hg either at rest or during provocation.
Exercise would be the optimal physiological
mechanism to provoke a labile obstruction
but is difficult in the catheterization
laboratory.
Isoproterenol infusion is an excellent
method to simulate exercise by stimulating
both B1 and B2 receptors.
Left, There is no left ventricular outflow
gradient at rest.
Middle, With initial infusion of
isoproterenol, there is a 40-mm Hg gradient
across the left ventricular outflow tract.
Right, With a greater infusion of
isoproterenol, there is a 65-mm Hg left
ventricular outflow gradient

43. SELECTION OF SEPTAL BR
• Standard diagnostic coronary cineangiography is performed as a first step
to clearly define the patient’s anatomy and to evaluate for concomitant
atherosclerotic disease.
• selection of the appropriate septal perforator branch through which to
perform the ablation. the camera should be positioned in the (RAO CR/AP
CR)
• It is also important to determine the septal vessel’s course along the
septum (i.e., on the right or left side), using the left anterior oblique (LAO)
projection.
• (SUB SELECTION OF SEPTAL BR) septal anatomy may vary such that one
subdivision runs along the left side of the septum and another runs
along the right.
• Selection of the left-sided subdivision is optimal for the ablation,
because there is a reduced likelihood of inducing complete heart block
during ethanol infusion.
• Most septal perforators arise from the LAD, substantial anatomic
variation has been described in which the vessels may arise from the left
main trunk, the ramus intermedius, the left circumflex artery, diagonal
branches, or even a branch of the right coronary artery

44. PROPHYLACTIC TPM PRIOR TO HAPARIN
• A temporary transvenous pacemaker is placed in
advance as a prophylactic measure in case of the
development of complete heart block during, or in
days after, the ablation.
• After successful placement of both the temporary
pacemaker and the arterial sheath, heparin is
administered to achieve an activated clotting time
of 250 to 300 seconds to prevent thrombosis in
guide catheters and on wires.

45. METICULOUS WHILE CHOOSING THE SEPTAL ARTERY
• After angiographic identification of the septal
arteries, close attention must be given to
1. vessel size,
2. angulation, and
3. the distribution of myocardial territories served
by the given vessel.

46. DIFFICULTY WITH ANGULATED VESSEL
• Angulation of the septal vessels, either at the
origin from the primary vessel (e.g., the LAD) or
at the bifurcation of a larger septal artery, is an
important consideration in vessel selection.
• Vessels with angulations greater than 90
degrees are often technically challenging and
result in difficulty passing the balloon into the
selected vessel, with frequent prolapse of the
wire into the mid-LAD.
• Specialized techniques using catheters that allow
control of the distal angle (Venture Catheter, St.
Jude Medical, St. Paul, MN) may be useful in
these circumstances.

47. VARIATION OF MYOCARDIUM SUBTENDED BY SEPTALS
• There is substantial variation in the distribution of blood flow supplied by
the septal perforators in patients with HOCM compared with the
unaffected population.
• In both autopsy and angiography studies, it has been demonstrated that
the first septal artery may provide blood flow to regions other than the
targeted basal septum (including the right ventricle);
• it may supply the basal septum incompletely and share this
responsibility with a second septal branch, or
• it may subtend a substantially larger distribution of myocardium than
would be expected.
• Therefore an intimate knowledge of the myocardial distribution of blood
flow supplied by the selected septal branch is essential to accurately
target the correct area for ablation and to avoid infarction of an
unanticipated region or an oversized infarction of the septum itself.
• This is most commonly accomplished during the procedure by the selective
injection of dye under cine guidance and the concomitant use of
transthoracic echocardiography (TTE) using injectable contrast material .

48. PROCEDURE
• After angiographic assessment of the septal anatomy, a guide
catheter providing extra support (such as a 6- or 7-Fr XB
catheter) is used to engage the left main trunk.
• Subsequently, a 0.014-inch extra support wire with a soft tip is
passed into the selected septal perforator branch, most
commonly the first septal perforator
• A short angioplasty balloon, usually 1.5 to 2 mm in diameter
and 10 mm in length, is passed over the guidewire and into the
septal branch. Difficulty in passing the balloon may be resolved
by use of a stiffer guidewire to provide greater support for
balloon placement.
• Care must be taken to seat the balloon deeply enough into the
septal artery and to fully expand the balloon to ensure that the
injected ethanol is not refluxed in to the LAD.
• Conversely, if the balloon is placed too deeply into the septal
vessel, the injected ethanol may spare the basal portion of the
septum, resulting in an unsuccessful procedure

49. TO VERIFY THE DISTRIBUTION OF MYOCARDIUM BEING SUPPLIED BY
THE SELECTED VESSEL
• It is essential at this point to verify the distribution of myocardium being
supplied by the selected vessel, given the substantial degree of variability
in the cardiac anatomy in this patient population.
• This can be accomplished by traditional angiography or TEE, often with
the aid of echocardiographic contrast.
• After correct positioning, as described earlier, the operator inflates the
balloon (typically to 10 to 12 atmospheres) to occlude the perforator, and
1 to 2 mL of contrast material is injected to assess the full extent of
myocardium supplied by the chosen vessel.
• Contrast should be injected slowly so as to mimic the anticipated alcohol
infusion.
• Extreme caution should be taken to verify that the infused contrast
material does not reflux into the LAD or into other coronary arteries
(e.g., the posterior descending artery), thus possibly exposing a large
amount of unintended myocardium to damage when the ethanol is
infused.
• Aggressive contrast infusion may overwhelm collateral vessels and create
an inferior LV wall infarction.

50. CONTRAST ECHO
• After angiographic confirmation of septal occlusion, further assessment of the septal
distribution is obtained via contrast echocardiography
• After careful inspection of the septum in the apical long-axis, four-chamber, and
parasternal long-axis views, 1 to 2 mL of Albunex contrast is injected into the septal branch
through a tuberculin-type syringe.
• Because Albumex, a first-generation echocardiographic contrast agent, is no longer
available in many countries, second- and third-generation agents are currently used.
These agents have proved to be suboptimal because they traverse the capillary beds
rapidly and produce a large amount of echocardiographic “shadowing” from the opacified
ventricles. Therefore, it is important to dilute these agents before injection. In our
laboratory, the contrast vials are typically opened 10 to 15 minutes before the time of
expected use so as to decrease their potency. The contrast is then further diluted with
sterile saline in a 1 : 5 or 1 : 10 mixture at the time of injection.
• Pulsed-wave Doppler echocardiography is the imaging method of choice in using the
diluted contrast material to avoid destruction of the microbubbles with the higher-
frequency continuous-wave ultrasound.
• This procedure allows the operator to verify that the chosen vessel primarily supplies the
proximal interventricular septum and not portions of the inferior wall, LV papillary
musculature, or right ventricular free wall via the moderator band.
• Ideally, contrast material will appear in the basal portion of septum responsible for the
greatest extent of septal-mitral contact.
• Appearance of contrast in the distal septum or other regions of myocardium is a
contraindication to ethanol infusion, because it can result in infarction of an undesired
territory or an infarction of unanticipated size.

51. CONTRAST ECHO
• As a final method of ensuring that the desired
area of myocardium has been selected, it is
recommended that the operator document a
greater than 30% reduction in the LVOT gradient
during balloon inflation.
• A rather rapid reduction in gradient can be
observed with prolonged balloon occlusion of a
septal perforator branch.
• Such an observation suggests that the correct
septal distribution has been targeted for ablation.

52. METHODS TO ASSURE CORRECT
SEPTAL IS CHOSEN
• CONTRAST ECHO
• greater than 30% reduction in the LVOT
gradient during balloon inflation

53. CHECKLIST BEFORE ETHANOL INJ
• Before proceeding with ethanol injection, it is
essential to confirm that the balloon has not
migrated during this process (CONTRAST ECHO) -
--This is easily done by fluoroscopic verification
and injection of another 1 to 2 mL of contrast
agent through the guide catheter.
• previously placed temporary pacemaker
continues to have a suitable pacing threshold.

54. ETHANOL INJ
• After confirmation of proper balloon positioning, the operator may
proceed with ethanol injection.
• Whereas most experienced centers use between 1 to 3 mL of desiccated
ethanol, this volume may be adjusted based on the appearance of the
septal anatomy and the degree of contrast washout.
• If there is rapid contrast washout due to collateralization of the septal
branch,
 the rate and volume of ethanol infusion should be reduced to prevent the
alcohol from escaping to undesirable areas of myocardium via the
collaterals
• The ethanol is injected into the vessel over a 1- to 5-minute period with
the balloon remaining inflated.
• During the initial infusion, continued monitoring of the resting gradient is
essential to judge the efficacy of the procedure. In general, a
• reduction in the LVOT gradient to less than 30 mm Hg in the setting of a
resting gradient greater than 50 mm Hg, or a greater than 50% reduction
of a provocable gradient, is considered indicative of a successful
procedure in the catheterization laboratory

55. Successful procedure in the
catheterization laboratory
• REDUCTION IN THE LVOT GRADIENT TO LESS
THAN 30 MM HG IN THE SETTING OF A
RESTING GRADIENT GREATER THAN 50 MM
HG
• GREATER THAN 50% REDUCTION OF A
PROVOCABLE GRADIENT

56. PROCEDURE
• Before the balloon is disengaged from the septal vessel, it is
recommended that the guidewire be placed again into the
septal branch for smooth removal of the balloon and
maintenance of access across the left main trunk and the
LAD.
• As a final step, angiography of the LAD and septal vessels
is performed to verify the integrity of the coronary
circulation. Phasic flow may be observed in the injected
septal branch immediately after the ablation, although
total occlusion is frequently observed.
• The amount of induced myocardial tissue destruction often
results in elevation of the enzyme creatinine
phosphokinase (CPK) to levels between 800 and 1200 U/L,
• The transvenous pacing wire may be discontinued 48 hours
after the procedure if there is an absence of
bradyarrhythmia or heart block that would require
continued observation or a permanent pacemaker

57. CAG AFTER ETHANOL INJ
• As a final step, angiography of the LAD and
septal vessels is performed to verify the
integrity of the coronary circulation.
Phasic flow may be observed in the injected
septal branch immediately after the ablation,
although total occlusion is frequently
observed.

58. Complication(INTRAPROCEDURAL)
• The complication rate after septal ablation is relatively low and is comparable to
that of septal myectomy.
• As opposed to the LBBB so commonly observed after septal myectomy, a right
bundle branch block (RBBB) is observed in up to 80% of patients who have
undergone ablation.
• The incidence of complete heart block has decreased in recent years and now
ranges from 5% to 40%, with an average value of 12% to 15% at experienced
centers. The presence of a preexisting LBBB and a rapid bolus injection of
ethanol during ablation have both been positively correlated with an increased
incidence of high-degree atrioventricular block requiring permanent pacemaker
implantation.
• Extravasation of alcohol into the LAD during infusion is a rare but catastrophic
complication that often results in a large infarction of the middle to distal
anterior wall and is clearly associated with increased mortality.
• Coronary dissection caused by the extra support guidewire or the catheter has
been reported in rare instances.
• Tamponade due to perforation of the right ventricular apex during insertion of a
transvenous pacing wire or during interatrial septal puncture for periprocedural
hemodynamic monitoring has also been reported.
• Overly extensive infarction of the interventricular septum as a result of too
generous a quantity of infused alcohol or too rapid an infusion rate during
ablation can result in a ventricular septal rupture.

59. VT AFTER SEPTAL ABLATION
• Ventricular arrhythmias can be seen both during and up to
48 hours after the procedure, but this complication is rare
and usually does not require prolonged therapy.
• Unlike myectomy, septal ablation results in the formation
of a large intramyocardial scar that may serve as substrate
for future malignant ventricular arrhythmias.
• There has been some conjecture that this could result in an
increased risk of late arrhythmic mortality, especially in
younger patients undergoing ablation.
• Patients should be observed closely for recurrence of
symptoms or any arrhythmia.
• ICD implantation should be considered if there is evidence
of nonsustained VT, but this is extremely rare.

60. FOLLOW UP
• Objective assessment of functional capacity
using exercise testing is appropriate for
monitoring these patients.
• Repeat alcohol ablation may be considered if
symptoms recur and an appropriate septal
perforator is available for injection.
• If repeat ablation is not feasible, surgical
myectomy may need to be considered in this
group.

72. MECHANISM OF MR IN HOCM
• The mechanism of MR in HOCM is attributed to the following .
1. Asymmetric septal hypertrophy (ASH ) related abnormal pap muscle
alignment (Geometric distortion )
2. Exaggerated SAM(AML is attracted towards LVOT with every systole
that tend to keep the mitral valve unguarded and MR results)*
3. Intrinsic abnormalities of mitral valve.
4. Associated MVPS
5. VPDs and Non-sustained VT can result in transient MR
6. Pacemaker mediated MR (DDD pacemaker was used to induce
desynchrony of LVOT vs LV free wall .This concept is almost a
failed one now !)
7. End stage HOCM -Left ventricular dilatation
• * This mechanism is considered less important , as SAM is almost
universal in HOCM but MR occurs in less than 20% patients with
HOCM.

73. • LVOT jet is different from MR
jet in size, shape, timing and
site of maximum signal . Still it
is often be confused with one
other. Most common reason
for this is technical .
• A careful apical 4 chamber
view with well opened LVOT
will reduce the error .
• Never record a HOCM echo
without ECG gating .
• The MR jet may be very trivial
in color flow but doppler will
still pick the signal well .
• Realise ,for hemodyanmic
reasons MR jet must be always
more than LVOT jet.Finally if
you get a report a LVOT
gradient > 100mmhg in HOCM
suspect it to be MR ! More
often your suspicion will prove
to be right