Pulsus parvus et tardus

Pulsus parvus et tardus refers to a late (i.e., tardus), weak (i.e., parvus) pulse (i.e., pulsus) relative to heart contraction and is commonly felt during a physical examination of an individual with aortic valve stenosis. Pulse, or heart rate, is the number of heartbeats per minute. Aortic stenosis is a common heart disease among older adults that can lead to heart failure and death if left untreated.

The heart consists of four chambers, consisting of the right and left atria, which are the top chambers, and the right and left ventricles, the bottom chambers. Typically, blood flows from the veins into the heart, from the right to left heart chambers, and then out through the arteries to the rest of the body. Ventricular contraction pushes the blood into the arteries, an action called “systole.” The systole is what is felt in a pulse. Valves, located between each heart chamber, close shut each time the heart contracts, producing a heart sound. 

Aortic valve stenosis is characterized by the narrowing of the aortic valve, which is located between the left ventricle and the aorta, a large artery that pumps oxygenated blood from the heart to the body. The narrowing minimizes blood flow to the rest of the body and can increase pressure in the left atrium. The decreased blood flow causes the heartbeat to weaken and be late or out of rhythm. This change in heartbeat is called pulsus parvus et tardus. 

Pulsus parvus et tardus usually indicates aortic valve stenosis, which is most commonly caused by aging. As people age, damage to the heart may occur and lead to scar tissue formation around the valve. Additionally, calcium deposits may form as calcium passess through the artery. The scar tissue and calcium deposits are naturally occurring processes that can decrease the size of the aortic valve opening. In addition to age, a history of smoking, hypertension (i.e., high blood pressure), and high cholesterol are also risk factors for developing aortic stenosis.

Less commonly, aortic stenosis can be caused by a bicuspid aortic valve, an inherited heart defect. With a bicuspid aortic valve, an individual has only two cusps, the flaps that make up the valve, instead of the typical three cusps. Even less frequently, an individual may be born with only one cusp, called a unicusp. Having fewer cusps may decrease the size of the opening that blood flows through when exiting the left ventricle. If the blockage is severe, symptoms may begin in childhood or adolescence.

Also in younger people, aortic stenosis may result if the aortic valve does not grow at the same pace as the rest of the body. An aortic valve that is significantly smaller than the rest of the heart reduces the amount of blood that can flow through the valve.

Rarely, aortic stenosis appears in adults who during childhood had rheumatic fever, a long-term complication of a strep throat infection. This would occur if the infection spread to the valve and caused damage that resulted in the formation of scar tissue. Scar tissue can make the aortic valve more stiff and less able to respond to blood flow.

Certain conditions are commonly concurrent in people with aortic stenosis, including hypertension; aortic regurgitation, in which the aortic valve does not fully close; and coronary artery disease, which is characterized by plaque buildup in the arteries that supply blood to the heart.

Pulsus parvus et tardus is noticeable during a physical examination, when the clinician checks the arterial pulse while listening to the heart at the same time. A pulse is usually checked at one of the carotid arteries, the large arteries that run on both sides of the neck, with two fingers placed over the artery near the top of the neck. The second heart sound and pulse should be simultaneous. However, if the pulse occurs after the heart sound, it indicates pulsus parvus et tardus. 

Further diagnosis of aortic valve stenosis is explained in “Guideline for the Management of Patients with Valvular Heart Disease,” a report published by the American College of Cardiology and American Heart Association in 2020. In summary, initial evaluation begins with a review of symptoms and medical history, as well as a physical exam. Symptoms may include shortness of breath, chest pain, and extreme tiredness. During a physical exam, a clinician usually listens to the heart sounds through a stethoscope. A systolic murmur, characterized by a swishing sound between the first and second heart sounds, may be heard near the aorta and extend up the carotid arteries.

The first set of diagnostic tests performed often indicate a diagnosis of aortic stenosis and the severity of the condition. An electrocardiogram (ECG) shows changes in electrical activity of the heart, but these can be normal for about 10% of people with aortic stenosis. An ultrasound of the heart, also known as an echocardiogram, can be used to visualize the aortic valve in order to assess its size and movement. Commonly, transthoracic echocardiograms (TTE) are conducted on the chest wall to measure the size of the left ventricle and its systolic function. A TTE may also rule out aortic regurgitation. Doppler echocardiography is another option, as it can show how blood is moving through the heart, which is particularly useful to determine disease severity.

Follow-up diagnostic testing may clarify the diagnosis and ensure no other condition is causing the symptoms. A chest X-ray may be taken to check for an enlarged heart or calcifications on the aortic valve or aorta. Less commonly, an exercise or stress test, which requires the individual to exercise while attached to an ECG, may be performed in order to further assess possible symptoms. In some cases, computerized tomography (CT) scans or cardiac catheterization may be needed to confirm diagnosis and determine if there is concurrent coronary artery disease. Other types of tests, such as dental examinations, may also be conducted to rule out all possible causes and associated conditions.

Treatment for pulsus parvus et tardus varies by severity of the aortic stenosis. For mild to moderate aortic stenosis, lifestyle approaches may be encouraged. These may include exercising regularly, eating a balanced diet with many fruits and vegetables, and avoiding tobacco products. Sometimes medications may be recommended to lower blood pressure (e.g., thiazide diuretics) and cholesterol (e.g., statins). Individuals may also be encouraged to have regular cardiology checkups with an echocardiogram every 1 to 5 years, depending on the case severity. 

More severe cases of aortic stenosis may require surgery to repair or replace the valve. Early intervention can improve surgical outcomes and avoid more challenging symptoms, such as fainting or heart failure. In general, all surgeries for aortic stenosis have a low risk of death. 

Balloon valvuloplasty is one surgical option, generally considered for young people with aortic stenosis or older individuals who cannot undergo more invasive surgery. In balloon valvuloplasty, a catheter -- a small, thin tube -- with a balloon on the end is inserted into a vein or artery in the groin area, and when it reaches the aortic valve, the balloon is inflated to stretch the valve open. 

However, individuals with severe aortic stenosis may need an aortic valve repair, which is often done through a traditional surgery in which the chest is opened and the heart exposed, allowing for a direct repair. 

A complete valve replacement may be considered for other individuals with severe aortic stenosis. There are generally two possible approaches: performing surgery after opening up the chest or using a catheter to reach the heart. Transcatheter aortic valve replacement is typically used for people who are at high risk for surgery based on medical history and age. A replacement valve can be mechanical, made from metals or plastic, or bioprosthetic, which would be made of tissues from animals, a human donor, or the individual themselves. In general, mechanical valves last longer, but an individual with a mechanical valve must continually take blood thinners, such as warfarin. Decisions between surgical approaches and valve type take into consideration a variety of individualized factors, including the person’s medical history, personal values, and lifestyle.

Aortic stenosis may be prevented through minimizing risk factors of heart disease, such as high cholesterol and obesity. Additionally, preventing rheumatic fever by promptly treating strep throat with antibiotics can decrease one’s risk of aortic stenosis.

Pulsus parvus et tardus is a weak, late (relative to heart contraction) pulse indicating aortic valve stenosis, a common cardiovascular disease. Aortic stenosis is most commonly caused by accumulation of scar tissue and calcium deposit around the aortic valve. Pulsus parvus et tardus is often checked for during a physical examination, when a clinician checks the pulse in the carotid arteries while simultaneously listening to heart sounds. Diagnosis of aortic stenosis is made through a clinical examination, EKG, and echocardiography. Treatment depends on case severity. Treatment of mild-to-moderate cases often involves lifestyle approaches and monitoring. For more severe cases, surgery may be required to repair or replace the valve.