Dr. Kulick received his undergraduate and medical degrees from the University of Southern California, School of Medicine. He performed his residency in internal medicine at the Harbor-University of California Los Angeles Medical Center and a fellowship in the section of cardiology at the Los Angeles County-University of Southern California Medical Center. He is board certified in Internal Medicine and Cardiology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
How does aortic stenosis affect the left ventricle pump?
Symptoms and heart problems in aortic
stenosis are related to the degree of narrowing of the aortic
valve area. Patients with mild aortic valve narrowing may experience
no symptoms. When the narrowing becomes significant (usually greater
that 50% reduction in valve area), the pressure in the left ventricle
increases and a pressure difference can be measured between the
left ventricle and the aorta. An easy way to conceptualize the size issues is to think of a normal aortic valve as being about a "half-dollar" size in diameter, and a significantly narrowed valve to be less than a "dime" in size. To compensate for the increasing
resistance at the aortic valve, the muscles of the left ventricle
thicken to maintain pump function and cardiac output. This muscle
thickening causes a stiffer heart muscle which requires higher
pressures in the left atrium and the blood vessels of the lungs
to fill the left ventricle. Even though these patients may be
able to maintain adequate and normal cardiac output at rest, the
ability of the heart to increase output with exercise is limited
by these high pressures. As the disease progresses the increasing
pressure eventually causes the left ventricle to dilate, leading
to a decrease in cardiac output and heart failure.
In 4% of the patients with aortic
stenosis, the first symptom is sudden death, usually during strenuous
exertion.
The exact reason for sudden death is unknown. It may be due to heart rhythm abnormalities secondary to inadequate
blood flow through the narrowed aortic valve into the coronary
arteries of the heart. Insufficient oxygen to the inner lining of the heart muscle occurs do to the lack of blood flow to the coronary arteries, particularly during strenuous exercise. Lack of oxygen in
the heart muscles causes chest pain and possibly abnormal heart
rhythms.
Chest pain is
the first symptom in one-third of patients and eventually occurs in one-half of patients with
aortic stenosis. Chest pain in patients with aortic stenosis is the same as
chest pain (angina) experienced by patients with coronary artery disease. In
both of these conditions, pain is described as pressure below the breast
bone brought on by exertion and relieved by rest. In patients
with coronary artery disease, chest pain is due to inadequate
blood supply to the heart muscles because of narrowed coronary
arteries. In patients with aortic stenosis, chest pain often occurs
without any underlying narrowing of the coronary arteries. The
thickened heart muscle must pump against high pressure to push
blood through the narrowed aortic valve. This increases heart
muscle oxygen demand in excess of the supply delivered in the
blood, causing chest pain (angina).
Fainting (syncope) related to aortic stenosis is usually associated
with exertion or excitement. These conditions cause relaxation
of the body's blood vessels (vasodilation), lowering blood pressure.
In aortic stenosis, the heart is unable to increase output to
compensate for the drop in blood pressure. Therefore, blood flow
to the brain is decreased, causing fainting. Fainting can also
occur when cardiac output is decreased by an irregular heart beat
(arrhythmia). Without effective treatment, the average life expectancy
is less than three years after the onset of chest pain or syncope symptoms.
Shortness of breath from heart failure is the most ominous sign.
It reflects the heart muscle's failure to compensate for the extreme
pressure load of aortic stenosis. Shortness of breath is caused
by increased pressure in the blood vessels of the lung due to
the increased pressure required to fill the left ventricle. Initially,
shortness of breath occurs only during activity. As the disease
progresses, shortness of breath occurs at rest. Patients can find
it difficult to lie flat without becoming short of breath (orthopnea).
Without treatment, the average life expectancy after the onset
of heart failure due to aortic stenosis is between six to 24
months.
Low blood pressure, also referred to as hypotension, is blood pressure that is so low that it causes symptoms or signs due to the low flow of blood through the arteries and veins. Some of the symptoms of low blood pressure include light-headedness, dizziness, or even fainting if not enough blood is getting to the brain. Diseases and medications can also cause low blood pressure. When the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidneys; the organs do not function normally and may be permanently damaged.
Congestive heart failure (CHF) is a condition in which the heart's function as a pump is inadequate to meet the body's needs. A poor blood supply resulting from congestive heart failure may cause the body's organ systems to fail, leading to a weakened heart muscle and fluid accumulation in the lungs and body tissue. There are many diseases that can impair pumping efficiency and symptoms of congestive heart failure including fatigue, diminished exercise capacity, shortness of breath, and swelling. Treatments include lifestyle modifications, medications, heart transplant, and therapy.
Angina is chest pain that is due to an inadequate supply of oxygen to the heart muscle.
Angina can be caused by coronary artery disease or spasm of the coronary
arteries. EKG, exercise treadmill, stress echocardiography, stress thallium, and cardiac
catheterization are important tests used in the diagnosis of angina.
Fainting, also referred to as blacking out, syncope, or temporary loss of consciousness has many causes. Often a person will have signs or symptoms prior to the fainting episode. Diagnosis and treatment depends upon the cause of the fainting or syncope episode.
Heart valve disease occurs when the heart valves do not work the way they should. Symptoms of valve disease include shortness of breath, weakness or dizziness, discomfort in your chest, palpitations, swelling of your ankles, feet or abdomen, and rapid weight gain.
Sudden cardiac arrest is an unexpected, sudden death caused by sudden cardiac arrest (loss of heart function). Causes and risk factors of sudden cardiac arrest include (not inclusive): abnormal heart rhythms (arrhythmias), previous heart attack, coronary artery disease, smoking, high cholesterol, Wolff-Parkinson-White Syndrome, ventricular tachycardia or ventricular fibrillation after a heart attack, congenital heart defects, history of fainting, and heart failure, obesity, diabetes, and drug abuse. Treatment of sudden cardiac arrest is an emergency, and action must be taken immediately.
Endocarditis, a serious infection of one of the four heart valves is caused by growth of bacteria on one of the heart valves; leading to an infected massed called a "vegetation." The infection can be caused by having bacteria in the bloodstream after dental work, colonoscopy, or other similar procedures. Endocarditis symptoms include fever, fatigue, weakness, chills, aching muscles and joints, night sweats, edema in the legs, feet, or abdomen, malaise, shortness of breath and small skin lesions. Treatment for endocarditis is generally aggressive antibiotic treatment.
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