dilated cardiomyopathy

Surgery for DCM and RCM

Dr Amjad Shaikh

Introduction

Main treatment is for heart failure which is the end result of DCM and RCM.

Most of the surgeries still are under development.

Best treatment is heart transplant.

Surgery for DCM

Partial left ventriculectomy( Batista) Ventricular restoration Ventricular shape change and

constraint devices Direct cardiac or aortic compression

devices Dynamic cardiomyoplasty Biventricular pacing Mechanical circulatory support

Batista operation

Batista procedure, was developed and introduced by the Brazilian cardiac surgeon Batista.

Batista hypothesized that an enlarged, dilated ventricle would be a more effective pump if the size could be reduced, hence restoring the normal volume/mass/diameter relationship of the left ventricle.

The law of LaPlace states that wall stress is directly proportional to ventricular pressure and radius and inversely proportional to wall thickness.

removing a triangular wedge of the lateral wall of the left ventricle, which typically weighs more than 100 g . The incision begins at the apex of the left ventricle and extends to the atrioventricular groove.

Typically a posterolateral branch of the left coronary artery is removed with the excised specimen. Because of the change in geometry and juxtaposition of the papillary muscles, the mitral valve is repaired to ensure competency.

Batista performs a mitral valve repair (Alfieri technique), in which the anterior and posterior leaflets are sutured resulting in a double-orifice mitral valve, which yields the characteristic figure-of-eight appearance when the mitral valve is viewed in the short-axis echocardiographic view

Batista surgery

2D Echo: figure of eight

Advantages: it improves systolic function and hence cardiac output..

Limitations: It removes functioning though

weakened myocardium. It may actually decrease net ventricular pumping capacity by affecting diastolic compliance.

Ventricular restoration

Anatomical basis: - heart is dual spiral helix( torrent –

Gausp) -configuration of muscle fibers at apex is

figure of eight which provides mechanism for ventricular ejection and suction of filling.

Aim of surgery: convert spherical heart to normal

elliptical heart

Ventricular shape change and constraint devices These devices change left ventricular shape

or to restrain ventricular dilatation of heart. McCarthy and schenk used myosplints: three of devices are placed

perpandicular to long axis of left ventricle.Chaudhary used prosthetic jacket of knitted

polyster mesh: it prevents progressive left ventricular remodelling and abolished functional mitral valve regurgitation.

Direct cardiac or aortic compression devices It helps failing heart by direct compression of heart

and aorta. It avoids interaction between blood and foreign

surface of assist device. Ease of application and ease of removal.

A: The cardio support system: it surrounds both ventricles to the AV groove - -200 mm Hg pressure for vaccume seal. - compression bladder inflated and deflated in

synchrony with cardiac contraction. - short term use for cardiogenic shock.

B: The heart booster: - multiple small parallel

compression tubes covering both ventricular chembers.

- hydraulic drive system fills and empties the tubes

- still under development stage

C: Kantrovitz CARDIOVAD( LVAD):

Principle: diastolic augmentation like IABP.

- the pump is warn externally and provides the stroke volume of up to 60 ml via the tube through the skin.

Dynamic Cardiomyoplasty

Basic: use of the skeletal muscle wrapped around heart which is stimulated electrically to augment or restore contractility of ventricles.

Kantrovitz and McKinon used first in 1959.

Latissimus dorsi muscle used. Electrodes are implanted in muscle and

stimuled in synchronization with heart Late deaths are seen due to ventricular

arrhythmias and fibrillation.

Mechanical circulatory support It is a means of imparting energy for

forward flow of blood in the body by man made device.

It can be

A: - temporary

- interim

- permanent

B: - internal (implantable)

- external( partially implantable, paracrporeal)

Implantable or partialy implantable A: Ventricular Assist Device: - VADs are connected to the failing

heart in parallel. - it pumps all or part of stroke volume.- It generally bypass the failing heart.- It takes blood from atria in to the

pump and return to great arteries beyond the ventricle.

- It provides pulsatile blood flow

Paracorporeal VADS

Abiomed VAD

Thoratec VAD

It is particularly useful in smaller adults or older children.

Pumping ventricle is mounted on the abdomen and canula from ventricle are brought out of mediastinum as drainage tube.

Rate is determined automatically. The pump is flow limited to about

5l/m.

Implantable VADS

Thoratec heartmate VAD II used as bridge to heart transplant.

It improves the chance for survival until the suitable donor can be located.

Pump is driven pneumatically or electrically.

Many newer modifications are available now.

Total artificial heart

Both ventricles are replaced by biventricular pneumatic pulsatile blood pump maintaining natural atria as inflow chambers.

cardiowest C-70

Recent advances

Now continuous flow and centrifugal pumps are available.

these are smaller pumps Energy requirement is low Pumps do not require compliance

chamber. Disadvantages: needs anticoagulants thrombus

formation hemolysis.( Nimbus heartmate II VAD)

Last resort….

Heart transplant…

Thank you….