Hello and I am sorry I am just getting to your thread now as I was out of town.
Yes your Cardiomyopathy may have worsened in that time frame. I do hope you have already contacted a Dr. or Cardiologist to receive a medical screening exam. Remember we are not professional physicians here in the forum.
With your documented dx of cardiomyopathy always assume it may be your heart when you become symptomatic with palpitations and chest tightness off and on and shortness of breath.
Also watch for dizziness, lightheadedness and fainting; fatigue, swelling of feet ankles and legs and bloating of abdomen with fluid.
Ejection fraction is a measurement of the percentage of blood leaving your heart each time it contracts.
During each heartbeat cycle, the heart contracts and relaxes. When your heart contracts, it ejects blood from the two pumping chambers (ventricles). When your heart relaxes, the ventricles refill with blood. No matter how forceful the contraction, it doesn't empty all of the blood out of a ventricle. The term "ejection fraction" refers to the percentage of blood that's pumped out of a filled ventricle with each heartbeat.
The left ventricle is the heart's main pumping chamber, so ejection fraction is usually measured only in the left ventricle (LV). An LV ejection fraction of 55 percent or higher is considered normal. An LV ejection fraction of 50 percent or lower is considered reduced. Experts vary in their opinion about an ejection fraction between 50 and 55 percent, and some would consider this a "borderline" range.
Remember the numbers do play a role in dx heart disease but paying attention to how you feel and sx is extremely important.
Let us know how you are doing.