Cardiomyopathy

Question 1

Hypertrophic cardiomyopathy

Answer 1

Subvalvular left ventricular outflow obstruction from septal muscle hypertrophy

Question 2

Physiologic effects of hypertrophic cardiomyopathy on mitral valve

Answer 2

abnormally high blood velocity –> Venturi effect on the anterior leaflet of the mitral valve –> Systolic anterior motion (SAM)

Question 3

Alternative to open surgery for Hypertrophic cardiomyopathy

Answer 3

1. Dual chamber ventricular pacing

2. Alcohol septal ablation of the first septal perforator artery of the LAD

Question 4

Indication for surgical intervention (4)

Answer 4

1. Transvalvular gradient of 50 mmHg
2. Provokable gradient of 60 mmHg
3. Asymmetric thickness of interventriclar septum >1.5 cm
4. Pacemaker is required in approximately 10%

Question 5

Classification of ventricular aneurysms

Answer 5

True aneurysm and false (pseudoaneurysm)

Question 6

‘True’ ventricular aneurysm

Answer 6

Due to dilation and remodeling of a transmural infarction. Well-defined, isolated scars composed of fibrous tissue that are devoid of muscle, thinned out, bulding outward, akinetic or dyskinetic.

Question 7

‘False’ ventricular aneurysm

Answer 7

pseudoaneurysm. Due to contained rupture of ventricle wall

Question 8

Indication for surgery of a ventricular aneurysm

Answer 8

Large ‘true’ aneurysm that contributes to angina or heart failure. Almost all pseudoaneurysm (unless small and incidentally noted)

Question 9

Left ventricular free wall ‘rupture’ operative mortality.

Answer 9

Almost always lethal without surgery. Operative mortality 25%.

Question 10

Operative techniques for LV free wall rupture

Answer 10

a. Excision of infarct and patch repair. Not ideal for new infarcts and poor tissue integrity.
b. Direct closure with felt pledgets
c. Patch and glue repair. A small rent in the myocardial tissue is covered with bovine pericardium ~2 cm larger than the size of the defect + Bioglue

Question 11

Initial management of Post-infarct VSD

Answer 11

IABP, or ECLS if severe end organ damage

Question 12

Mortality rate of Post-infarct VSD

Answer 12

at least 25% in 1 day of diagnosis; 80% in 1 month

Question 13

Operative techniques for Post-infarct VSD

Answer 13

Patch exclusion is better than patch repair; or total artificial heart

Question 14

Indication for surgical intervention for LV aneurysm (7)

Answer 14

Symptoms of heart failure, angina, arrhythmia, mural thrombus, enlargement, pseudoaneurysm, and embolism

Question 15

Name of trial on management of LV aneurysm

Answer 15

STITCH trial

Question 16

STITCH TRIAL

1) Inclusion criteria
2) Cohorts of the study
3) Findings

Answer 16

• Inclusion: EF <35% and operable CAD
• Cohorts:
  1. Medical therapy alone vs. CABG + medical
  2. CABG + medical vs. CABG + medical + surgical ventricular reconstruction (SVR)
• Survival benefit was realized in CABG + SVR compared to CABG alone when a postoperative end-systolic volume index of 70 mL/m2 or less was achieved.
• Little added benefit in most patients.