Invasive procedures, requiring anesthesia and an overnight hospital stay, may be necessary to gain a better understanding of the damaged heart. Cardiac catheterization is the most accurate tool for determining the severity of cardiomyopathy. If cardiomyopathy is suspected to be associated with a systemic disease affecting multiple organs, a muscle biopsy or genetic testing may be incorporated into the evaluation process.

Cardiac Catheterization

During this procedure a thin flexible tube called a catheter is inserted into a blood vessel in the arm or leg and threaded through a blood vessel to the heart. Using contrast dye that is injected into the catheter, special x-ray videos (angiograms) are taken of the heart valves, coronary arteries, and chambers to assess the heart’s pumping ability.

Catheterization can be used for both diagnostic and therapeutic purposes. This includes evaluating patterns of blood flow within the heart, checking on blockages in the arteries, and measuring pressures in the heart chambers. The information provided during catheterization may be helpful if a heart transplant is being considered. Certain procedures that may be performed at the same time include an angiogram, endomyocardial (cardiac) biopsy, or an electrophysiology study.

Coronary Angiography

This test helps to visualize the inside of the heart blood vessels and chambers. Contrast dye is injected into a catheter that is inserted into a blood vessel leading to the heart. The flow of the dye is visible by x-ray and can be tracked on a video monitor and recorded. This procedure evaluates blood pressures and blood flow inside the heart to determine how well the heart is functioning.

Electrophysiology Study

If the heart is not beating normally, an electrophysiology (EP) study is done to investigate the cause, location, and possible treatment. An EP study records the heart’s electrical activity and electrical pathways. Similar to a cardiac catheterization, electrode catheters (flexible fine wires with metal electrode tips) are inserted into a blood vessel that leads to the heart. Electrical stimuli is applied to the wires to induce a fast heart rhythm. An EP study checks for slow or fast arrhythmias, provides information on the effectiveness of anti-arrhythmic drugs, and indicates whether a pacemaker or implantable cardioverter defibrillator is needed.

Endomyocardial Biopsy

Also known as a cardiac muscle biopsy, this procedure uses a catheter to remove tiny pieces of heart muscle tissue for microscopic inspection. This procedure is used for evaluating heart damage caused by infection, inflammation, metabolic issues, or structural abnormalities of the heart muscle.

Skeletal Muscle Biopsy

This procedure involves removing a tiny piece of muscle from the arm or leg to test for mitochondrial cardiomyopathy or Duchenne muscular dystrophy, a neuromuscular disease associated with cardiomyopathy. This procedure is recommended when not enough muscle tissue can be extracted from a cardiac biopsy.