your relative"s heart pumping power is less( LVEF= 20%), NORMAL IS ABOVE 55 %
many patients of low ejection fraction
remain in sub clinical heart failure
, in this state angiography will precipitate profound heart failure , thats why your doctor advice
him angiography after stabilization with medicines.
another doctor suggested you about pacemaker , i think doctor advice you ICD ( INTRA CARDIAC DEFIBRILLATOR) with or without CRT. because it prevent sudden cardiac death
due to VT/VF , which is very common in patient with low ejection fraction.