This document discusses dilated cardiomyopathy (DCM), the most common type of cardiomyopathy. It provides details on: 1) The causes, symptoms, signs, diagnostic tests and goals of treatment for DCM. The mainstay of therapy includes vasodilators, digoxin and diuretics. 2) The morphological and microscopic features of DCM which involve enlargement and spherical dilation of the heart chambers. 3) Disease progression can lead to marked left ventricular dilatation and circulatory failure if left untreated. Management aims to relieve symptoms and slow progression.

1. Dr Tarun Bhatnagar
Consultant Cardiac Anaesthesiologist
dr.tarunbhatnagar@yahoo.co.in

2.  WHO in 1995 defined Cardiomyopathies as
diseases of myocardium associated with cardiac
dysfunction
 Types
Dilated Cardiomyopathy(DCM)
Hypertrophic Cardiomyopathy(HCM)
Restrictive Cardiomyopathy(RCM)
Arrythmogenic RVCardiomyopathy(ARVC)

4.  DCM is most common of all CMs(60%)
 Aetiology
-Idiopathic (50%)
-Myocarditis (9%)
-Ischemic (7%)
-Others-Viral, Peripartum, Substance abuse etc
 Morphologically
Enlargement of RV & LV cavities without an increase
in ventricular septal or free wall thickness →
spherical shape & dilatation of heart → Displacement
of papillary muscles → Regurgitant lesions despite
valve leaflets being normal

5. Medslides.com 5
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6.  Microscopically –Patchy & diffuse loss of tissue
with interstistial fibrosis & scarring
 Systolic Dysfunction>>> Diastolic dysfunction
 SV is initially maintained by ↑↑ EDV
 With disease progression→Marked LV dilatation
with normal or thin wall →↑ Wall stress +
Valvular Regurgitation →Overt Circulatory
Failure

7.  Symptoms
-Typically pts c/o months of
fatigue, weakness, reduced exercise tolerance due
to CHF
-May also present as a Stroke, Arrythmia or
Sudden Death
 Physical Signs
-Tachycardia
-pulsus alternans
-Jugular venous distension
-Murmurs of AV valve regurgitation
-Gallop heart sounds

8.  CXR- Cardiomegaly , Pulmonary venous congestion
 ECG- Normal or low QRS voltage , abn axis, non
specific ST seg abnormalities, LV
hypertrophy, conduction defects, AF, Non sustained
VT
 2D Echo
 Coronary Angiography
-usually normal coronaries
-coronary vasodilatation is impaired by ↑ LV filling
pressures
-distinguishes b/w Ischemic & Idiopathic DCM
 Endomyocardial Biopsy
rarely valuable to identify the aetiology

11.  Aim of treatment
-Manage the symptoms
-Reduce the progression of disease
-Prevent Complications
 Mainstay of Therapy
Vasodilators
+
Digoxin
+
Diuretics

12.  ACE Inhibitors
-Indicated for all patients
- Reduce symptoms & improve effort tolerance
- Suppress ventricular remodelling & endothelial
dysfunction
-Reduce CV mortality
 Milrinone
-Selective PDE-3 inhibitor
-may improve quality of life but doesn’t affect
mortality
-rarely adm in chronic situations

13.  Spironolactone
used along with ACE Inhibitors has shown to reduce
mortality by 30% in a large double blind randomized
trial
 Digoxin
clinically beneficial as reaffirmed by two large trials in
adults
 β Blockers
untill recently contraindicated but recent studies show
that they not only provide symptomatic improvement
but substantial reduction in sudden death in NYHA
class II & III HF pts

14.  Amiodarone
-High grade ventricular arrythmias (Sustained VT or
VF) are common in DCM→↑ risk of SCD
-Preferred antiarrythmic agent as it has least negative
inotropic effect & proarrythmogenic potential
-Implantable Defibrillators are used for refractory
arrythmias
 Anticoagulants
-indicated for pts with moderate ventricular
dilatation+mod-severe systolic dysfunction
-H/O stroke , AF or evidence of Intracardiac
thrombus

15.  Dual Chamber Pacing
 Cardiomyoplasty
 LV Assist Devices
improved pts sufficiently to avoid transplant or
enable later transplant
 Cardiac Transplantation
has substantially prolonged survival in DCM pts
with 5 yr survival rate of 78%

16.  Cardiac procedures which DCM pts undergo
-Correction of AV valve insufficiency
-Placement of ICD device
-LV Assist device placement
-Allograft Transplantation
 Goals of Anaesthetic Mx
- Reduction of afterload
-Optimizing preload
-Minimize myocardial depression
 DCM pts are extremely sensitive to cardiac
depressant anaesthetic drugs

17.  Fentanyl-(30u/kg )provides excellent anaesthesia &
hemodynamics in pts with EF<0.3
 Remifentanyl- assoc with severe hypotension &
bradycardia ,therefore unsuitable in low EF pts
 Etomidate-least effect on cardiac contractility in pts
undergoing cardiac transplant
 Ketamine-excellent choice in combination with fentanyl
for induction in pts with severe myocardial depression
 Propofol-causes CV depression due to inhibition of
sympathomimetic activity & vasodilatation
 Volatile agents-Desflurane with lowest BG partition
coefficient may allow some benefit for rapid
induction, rapid recovery from anaesthesia & early
extubation

18.  Invasive hemodynamic monitoring
-Mandatory in pts with DCM undergoing surgery
-Physical s/s may not accurately reflect
physiological parameters
-Pts with Implanted defibrillators have severely
depressed cardiac function but are routinely
managed without a PAC
 Hemodynamic Instability
-managed by low dose of inotrope & vasodilator

19.  Afterload reduction
-improves regional & global indices of ventricular
relaxation & EF during anaesthesia when myocardial
depression may be significant
-it also reduces valvular regurgitation & volumes
 Patients on Amiodarone on long term basis
can interact with anaesthetic agents & further reduce
contractility & conduction-requires careful titration
 Arrythmogenic factors –
Hypokalemia, Hypomagnesemia, & Sympathatic
activation should be monitored & corrected

20.  Hypertrophic Obstructive Cardiomyopathy(HOCM)
Idiopathic Hypertrophic subaortic stenosis(IHSS)
Assymetric Septal Hypertrophy
 M/c genetic cardiac disease
Prevalance in adults-0.2%
 Primary myocardial abnormality with sarcomeric
disarray & assymetric LV hypertrophy

21. Massive left ventricular
hypertrophy, mainly
confined to the septum
Histopathology showing
significant myofiber
disarray and interstitial
fibrosis

22.  Causes:
Inherited, acquired,
unknown
 Autosomal
dominant
inheritance pattern
 >450 mutations in 13
cardiac sarcomere &
myofilament-related
genes identified
 ?? Role for
environmental
factors

23. Hypertrophic cardiomyopathy: variants
Hypertrophic cardiomyopathy morphology exhibits heterogeneity.
The mostcommon variant is assymetric septal hypertrophy involving
the entire septum

24.  Subaortic Obstruction
 Diastolic Dysfunction
 Myocardial Ischemia
 Mitral Regurgitation
 Arrythmias

25.  Cause -Assymetrical Septal Myocardial Hypertrophy
 Unlike Aortic stenosis hypertrophy begets pressure gradient , not
the other way around
 Wide spectrum of severity of obstruction ch by
Variability- absent to critically severe
Dynamic nature - depends on contractility & loading conditions
Timing - begins early & peaks variably
Location -subaortic

26.  Subaortic Obstruction
Cause-Hypertrophic septum encroaching on the systolic
outflow tract
Bounded-Anteriorly by IVS & Posteriorly by AML
Effect-Systolic anterior motion(SAM) of AML →
accentuating obstruction
Mechanism of SAM
Thickened IVS→Restricted LVOT → ejection of blood at
a higher velocity closer to the AML → Drawing of AML
closure towards the hypertrophied septum due to the
venturi effect during LV systole→ Dynamic LVOT
obstruction

28.  Factors aggravating SAM & producing Dynamic
Obstruction-
-↑ Contractility
-↓ Afterload (Aortic outflow resistance)
-↓ Preload (End diastolic volume)
 Therapeutically Myocardial depression, Vasoconstriction &
Volume overloading should minimize obstruction & augment
forward flow
 LVOT gradient ≥ 30mmHg assoc with physiologic &
prognostic importance
 LVOTO is assoc with ↑ wall stress, myocardial
ischemia, cell death & eventually fibrosis→VT /VF
 Dynamic LVOTO may also occur in Cardiac tamponade
or Acute MI

29. Hypertrophied & disorganized myocytes with ↑CoT
Impaired relaxation+ ↑ Chamber stiffness
Diastolic Dysfunction→↓ rate of rapid ventricular filling
↑ atrial systolic filling
↑ Filling pressures & pulmonary congestion

30.  Myocardial Ischemia
◦ Often occurs without atherosclerotic coronary artery
disease
◦ Postulated mechanisms
 Abnormally small and partially obliterated intramural
coronary arteries as a result of hypertrophy
 Inadequate number of capillaries for the degree of LV mass

31.  Dyspnea on exertion (90%)
 Angina (70-80%)
 Syncope (20%)
 Sudden cardiac death

32.  ECG-↑ QRS voltage, ST-T changes, Axis
deviation, LV Hypertrophy +strain pattern
 CXR-Lt atrial enlargement or normal
 Echo
 Invasive Cardiac Cath- indicated for suspected
CAD or Severe mitral valve disease
- shows LV pressure gradient,↓ ventricular
volume, ↑ LVEDP

36.  Pharmacological
 Surgical
 Non Surgical Alternatives
 Implantable Cardioverter Defibrillator(ICD)
 Cardiac Transplantation

37.  β Blockers- mainstay of therapy
relieves symptoms of exercise intolerance & dyspnoea assoc with
CHF by- negative inotropic effect
-HR reduction
-lower myocardial O2 demand
- longer diastolic filling times
 CCB-Verapamil is indicated if β Blockers not tolerated or
ineffective
-it improves diastolc function & ventricular relaxation causing
improved filling decreased obstructive features in 50% pts
-CCBs with strong vasodilatory effect are C/I in pts with
obstructive symptoms
 Disopyramide- has negative inotropic & vasoconstrictive effects
-most effective agent to reduce LVOTO , gradient & relieving the
symptoms

38.  Indications
Subaortic gradients≥ 50mmHg frequently assoc with
CHF & are refractory to medication
 Septal Myotomy +Partial Mymectomy thru a
transaortic approach relieves the obstruction, reduces
the LVOTO gradient, SAM & MR
 Complications –CHB or septal perforation (0-2%)
 Mortality rate-1to 3%
 Intraop guidance & Evaluation of surgical result by an
experienced echocardiographer are essential for the
success of the procedure

39. Nishimura RA et al. NEJM. 2004. 350(13):1320.

40.  Septal Ablation with Ethanol
-Non surgical septal reduction therapy
-2-5 ml of Ethanol is adm thru an angioplasty balloon catheter
lumen to the first major septal perforator of the LAD
- reduce LVOT grad in 85-90% pts immediately
-Further ↓in grad & sympt improvement seen over next 3-6mths
- Permanent heart blocks ( 5-10%)
 Dual Chamber or AV Sequential Pacing(DDD)
-Exact mechanism unkn
-Possible mech: Excitation of the septum of LV contracts it away
from apposing wall which may reduce the LVOT gradient
-now rarely recommended since symptoms actually worsen despite
gradient reductions

41. .

42. Before After

43.  HCM is the most common cause of SCD in otherwise
healthy young individuals
 VT /VF is primarily responsible for SCD
 Identification of High Risk Individuals is very important
-Pts < 30yrs at the time of diagnosis
-Prior cardiac arrest
-Symptomatic VT on Holter monitor
-Family H/O SCD or Syncope
 The only effective modality to prevent SCD in HCM
pts is an ICD
 Pharmacological therapy for prevention of SCD in these
pts has been abandoned

44.  Aim of Anaesthetic management - Avoid aggravating the subaortic
gradient
 Anaesthetic goals for a patient with HCM are same for cardiac or
non cardiac surgery :
Preload- Increased
Afterload-Increased
Contractility-Depressed
Avoid tachycardia, Inotropes, Vasodilators
 To achieve these,
-Maintain adequate volume status
-Avoid direct or reflex increase in HR or contractility by heavy
premedication & maintaining adequate anaesthesia & analgesia
-Continuation of β blockers or CCBs upto the day of sx & restart
immediately after sx
-Use of vasoconstrictors to maintain MAP or CPP instead of
Inotropes

45.  Induction- IV Narcotics/
Propofol in carefully titrated doses can be used
 Maintenance-Halothane is advantageous because of its negative
inotropic & chronotropic effect
 Intraop Hypotension- Trendelenburg position, Volume
replacement, & Vasoconstrictors
 Arrythmia management
-Asymptomatic Nonsustained VT-benign
-Pts with ICD device needs to be suspended in presence of
Electrocautery
-Chronic AF :B Blocker+Verapamil
-Amiodarone is effectve in restoring NSR in pts with HCM
 Monitoring
ECG-closely monitor for arrythmias
CVP/PAC/TEE- for volume status, Hemodynamic monitoring
 Avoid Inotropes, B agonists & Calcium

46. HCM Athletic heart
 Can be asymmetric  Concentric & regresses with deconditioning
 Wall thickness: > 15 mm  < 15 mm
 LA: > 40 mm  < 40 mm
 LVEDD : < 45 mm  > 45 mm
 Diastolic function: always  Normal
abnormal  Occurs in about 2% of elite althetes – typical
sports, rowing, cycling, canoeing
46 of 48

47.  WHO in 1995 defined RCM as restrictive filling & reduced
diastolic volume of either or both ventricles with normal or
near normal systolic function & wall thickness
 Classification of RCM
 Myocardial
Nonifiltrative – Idiopathic, Familial, HCM, Diabetic
Infiltrative- Amyloidosis, Sarcoidosis
Storage diseases- Haemochromatosis, Glycogen storage diseases
 Endomyocardial
Endomyocardial fibrosis
Carcinoid
Radiation
Drug Induced –Serotonin, Methysergide, Busulfan, Ergotamine

48.  Hallmark –Abnormal Diastolic Dysfunction
 Impaired ventricular relaxation & abnormal Compliance causes
rapid filling in early diastole & impeded filling during rest of diastole
 Characteristic
-Ventricular diast waveform of Dip & Plateau (Square root sign)
-RA pressure waveform-M or W shaped due to rapid y descent
 Pressure in the ventricle rises precipitously in response to small
volume
 Both ventricles appear thick with small cavities in contrast to
corresponding dilated atria
 Lt sided Pulmonary venous pressure >Rt sided venous pressure by
5mmHg
 PASP↑↑ upto 50mmHg
 Either RVF or LVF or BVF

51.  Symptoms of Rt &/or Lt heart failure
 Kussmaul’s sign- ↑ JVP during inspiration
 Pulsus paradoxus- infrquent
 CXR- pulmonary congestion, small heart size
 ECG- BBBs, low voltage, QR or QS complexes
 2D Echo

53. Characteristic RCM Constrictive Pericarditis
Jugular venous ↑ with more rapid y descent ↑ with less rapid y descent
waveform
Paradoxical Pulse Rare Frequent
Auscultation Late S3, low pitched, S4 occ Early S3,highpitched, No S4
Heart size N to ↑ N to ↑
MR/TR Frequently present Frequently absent
CXR Pericardial calcification rare common
ECG Conduction abn common rare
ECHO Major enlargmt of Atria Slight enlargmt of Atria
LAP>RAP Always Absent
RVP waveform Square root pattern, Dip & Square root pattern
Plateau less prominent
RVEDP/LVEDP
LVEDP>RVEDP by ↑ ↑ & Equal
5mmHg
CT/MRI Rarely thickened Thickened pericardium>3mm
pericardium
Endomycardial Non specific abn Normal
Biopsy

54.  Idiopathic
Diuretics-To relieve congestion
B-blockers, Amiodarne, CCBs- Control of HR
Long term anticoagulation
CCBs, ACEI- To enhance myocardial relaxation
Dual Chamber Pacing- AV block
Cardiac Transplantation- Refractory Heart Failure
 Amyloidosis- Melphelan, prednisone, H+L transplant
 Haemochromatosis- Phlebotomy, Desferrioxamine
 Carcinoid- Somatostatin analogs, Valvuloplasty/Valve
replacement
 Sarcoidosis –Steroids , Pacing, ICD, Transplantation
 EMF with eosinophilic cardiomyopathy:
Endocardiectomy +TV/MV replacement

55.  Adults with RCM present for CT or MVR/TVR
 Diastolic dysfunction + filling abn- Poor CO & systemic perfusion
 Aggresive preop diuretic tharapy- Severe hypovolemia
 Pulmonary Congestion leads to ↑ Airway pressures
 Induction-Avoid drugs causing ↓ venous return, bradycardia &
myocardial depression
Fentanyl (30u/kg), Sufentanyl, Etomidate , Ketamine provide stable
hemodynamics for induction
Remifentanil, Propofol –unsuitable
 Invasive hemodynamic monitoring & TEE
 Inotropic support to maintain CO
 Diuretics / Vasodilators may be deleterious because higher filling
pressures are needed to maintain the CO

56.  Progressive replacement of RV myocardium with fat &
fibrous tissue creating an excellent envt of fatal arrythmias
 Typical involves regional RV→Global RV→Partial LV
involvement with sparing of septum
 Familial Inheritance, adolescents
 Presentation
-Onset of Arrythmias from RV range fromVPCs-VF
-SCD 75% due to VT/VF in sports related exercise
-CHF 25%
-Progressive RV & LV Dysfunction
 Diagnosis- Genetics, ECG, Serial Echo, EM Biopsy
ECG-Inverted T waves (Rt precordial leads)
QRS >110ms
Extrasystoles +LBBB

57.  Any Family H/O SCD or syncope at an early age must
alert the anaesthesiologist
 Arrythmias are more likely in the periop period
 Intraop /Postop Avoid any noxious stimuli
Light anaesthesia
Inadequate analgesia
Hypercarbia
Hypovolemia
Acidosis-detrimental due to its effect on arrythmia
generation & myocardial function
 GA perse doesn’t appear to be arrythmogenic
 Propofol , Midazolam, fentanyl-successfully used
 Amiodarone- Antiarrythmic of choice during
Anaesthesia