Hi,
As you have mentioned you have undergone multiple stenting (
PTCA), there is high possibility of compromised left ventricular function (which can be known from your
echocardiography 2DEcho report-- presence of regional wall motion abnormalities of heart wall, akinesia, hypokinesia , low left ventricular
ejection fraction)
Because of low left ventricular ejection fraction heart cannot pump adequate blood forward to fulfill need of body. That's why more breathing difficulty while exertion as there is more need for blood supply to body.
Sometimes there may development of back pressure changes on lungs and there is lung congestion which further agravate breathlessness.
That's why you should restrict you physical activity to minimal for your daily life, restrict daily water intake, you are in need of specific medicine like diuretics, B blockers, ACEI/ARBs along with blood thinners & statins, that help in removing extra water from body and prevent lung congestion, reduces work load on heart.