Heart Disease Research at MMRI

Heart failure also known as congestive heart failure, is a serious condition that occurs when the heart no longer can pump enough blood to meet the body's needs. This can occur if the heart is too weak or stiff to pump properly, or when it can't fill up with enough blood to eject properly to the rest of the body. Symptoms, including shortness of breath, fatigue, and/or excessive coughing, can range from mild to severe. Heart failure can develop over time, due to chronic conditions, or can occur suddenly, due to a sudden cardiac event or injury. Conditions that can cause heart failure include arrhythmia, cardiomyopathy, coronary artery disease, heart attack and high blood pressure.

Arrhythmia refers to having an abnormal rhythm or heart rate, whereby the heart beats either too fast (tachycardia), too slow (bradycardia), or irregularly (atrial fibrillation). There are many factors that can lead to an abnormal heart rhythm, including heart attack, smoking, excessive alcohol use, congenital heart defects, stress, electrolyte imbalance and certain medications. Having an arrhythmia can affect the heart's ability to pump blood effectively and when untreated, can lead to heart failure, stroke or cardiac arrest.

Atherosclerosis is a chronic condition characterized by the buildup of plaque inside the arteries. This plaque is composed of fatty deposits, cholesterol, calcium and other substances. Over time, the accumulation of plaque narrows and hardens the arteries, reducing or obstructing blood flow. This can lead to various cardiovascular problems, including heart disease, stroke and peripheral artery disease.

Cardiac fibrosis is a condition characterized by the excessive buildup of fibrous connective tissue in the heart, often referred to as “scarring” of the heart. Because fibrous tissue replaces healthy cardiac muscle cells, it can affect the heart muscle (myocardium) and disrupt the normal structure and function of the heart. Pressure overload, induced by hypertension or aortic stenosis, or a myocardial infarct (heart attack) can lead to extensive cardiac fibrosis, causing increased stiffness and diastolic dysfunction of the heart and eventually, to ventricular dilation and heart failure.

Cardiac inflammation is a natural response to an injury or infection in the heart that can lead to inflammation of the heart tissue. There are multiple types of cardiac inflammatory disorders. Myocarditis affects the heart muscle (myocardium), and is caused by infections, like viruses, or other medical conditions, like autoimmune disorders. Endocarditis affects the lining of the heart valves and is usually caused by bacteria in the blood. Bacteria can enter the blood from other infections, like urinary tract infections or gum infections, or from medical or dental procedures, leading to cardiac inflammation. Pericarditis affects the tissues surrounding the heart (pericardium). Autoimmune diseases, such as rheumatoid arthritis and lupus, can cause pericarditis. Symptoms for cardiac inflammation include chest pain, shortness of breath, fatigue and swelling in the legs, ankles and feet; treatment depends on the type of inflammation and can include medications, surgery or other types of procedures.

Diabetes, particularly type 2, significantly increases the risk of developing cardiovascular problems due to several interrelated factors that impact heart health. Cardiometabolic disorders refer to cardiac conditions that occur as a consequence of having had a heart attack, stroke, diabetes, insulin resistance, non-alcoholic fatty liver disease, hypertension, and/or other circulatory diseases. These conditions are considered to be largely preventable and are exacerbated by obesity, smoking, lack of exercise and poor diet. If left untreated, cardiometabolic disease can result in devastating health consequences, including heart failure.

Cardiomyopathies are diseases of the heart muscle (myocardium) that affect its structure and function, often causing the heart muscle to become enlarged, thickened, or rigid, and impacting the heart's ability to pump blood effectively. There are multiple types of cardiomyopathies, including dilated, hypertrophic, and restrictive, and they can be either inherited or induced by other medical conditions, including severe stress. Importantly, left unchecked, cardiomyopathies can lead to development of heart failure. While some people have no symptoms, others may experience shortness of breath, fatigue, dizziness, fainting, chest pain, swollen legs and feet and a bloated belly.

1:100 children are born with congenital heart diseases (CHD), equating to a staggering 1.3 million children each year, and the numbers continue to rise year after year. CHD refers to defects that are present at birth and affect the heart’s structure, including the cardiac muscle walls, valves, chambers and/or blood vessels that carry blood to and from the heart.

COVID-19 is caused by the SARS-CoV-2 virus. Infection with this virus can cause symptoms similar to the common cold, flu or pneumonia. COVID-19 may affect multiple tissues, including the lungs, respiratory tract, heart and circulatory system, increasing the risk of arrhythmias, such as atrial fibrillation and for myocarditis, inflammation of the heart.

An embolism is a blockage of a blood vessel caused by an embolus, which is a foreign substance or particulate matter that travels through the bloodstream and becomes lodged in a vessel. This blockage impedes or completely obstructs blood flow to the tissues supplied by the affected vessel, potentially causing significant damage or dysfunction.

Left Ventricular Non-Compaction (LVNC) is a rare and often under diagnosed form of cardiomyopathy where the left ventricle, the heart's main pumping chamber, fails to fully develop its normal compacted muscle layer. This results in a characteristic appearance of deep trabeculations (or spongy, mesh-like structures) within the heart muscle walls and intertrabecular spaces that are not properly compacted.

Thrombosis refers to the formation of a blood clot (thrombus) within a blood vessel, which can impede or completely block blood flow. This condition can occur in veins or arteries and may lead to serious health complications depending on the location and extent of the blockage.