1. c
Ostium secundum type is the most common seen in 80% of all cases of ASD. In ASD there is left to right shunting leading to pulmonary overflow. Surgery in asymptomatic patients is done usually at 4-5 years of age.
Closure of ostium secundum defects is accomplished either by direct suture or by insertion of a patch.
Sinus venosus ASDs associated with partial anomalous pulmonary venous connection are repaired by inserting a patch, with redirection of the pulmonary veins behind the patch to the left atrium
2. c
90% of the people have Right dominant coronary system , that means Right coronary artery ends as Posterior descending artery. If the Left circumflex artery supplies major branches to posterior descending artery, this system is called the left dominant system.
Left circumflex artery arises from Left Main coronary artery (LMCA) and gives of marginal branches, It ends as obtuse marginal artery.
in 0.5% cases it arises from Right coronary sinus
3. d
Main indications for coronary artery bypass grafting are
LMCA (Left Main coronary Artery) stenosis more than 60%
LAD or LCA stenosis more than 70%
Two or three vessel disease with LVEF (Left ventricular ejection fraction) less than50%
Two or three vessel disease with proximal LAD stenosis
4. d
All the above three are progressive pathological stages . There is fixation of both the valve and the subvalvular system. The pathological stage predicts the suitability of balloon valvuloplasty, commisurotomy or valve replacement
Also the valvular fibrosis and calcification may be related to repeated inflamation or turbulent flow.
Schwartz text book surgery 8th edition page 663.
5.c
Ventricular hypertrophy does not occur as the syenosed mitral valve protects left ventricle
6) c
All these congenital anomalies are seen with Coatctation of Aorta but Bicuspid Aortic Valve is the most common seen in 25-40% cases.
7) a
In coarctation of Aorta there is narrowing of lumen of Aorta distal to the left subclavian artery. There is hypertension and not hypotension because of left ventricular obstruction. There is increased formation of collaterals particularly of intercostal and internal mammary arteries leading to rib notching and predominant precordial pulsation. Femoral pulse is of low volume and delayed.
