Dull pain radiates under left arm sometimes under right arm

Need your input. Dull pain UNDER the left arm, sometimes shooting down left arm/elbow, sensations in left arm, shoulder, back shoulder blades, occasionally under the right arm. Brief health bio: left ventricular dysfunction, systolic and diastolic dysfunction. I went to ER several times, and nothing was shown on EKGs.. There is suspected coronary blocakge, and too unwell to undergo angiogram. History of arrythmias, such as tachy, SVT, PVCs, occasional AF.

The cardiologist suggests it could be microvessell disease, since I have those symptoms often, most of the time.