Pulsus Paradoxus

What is Pulsus Paradoxus?

Pulsus paradoxus is a medical term referring to an abnormal drop in a person’s blood pressure by more than 10 mmHg while they’re inhaling. This condition tends to occur due to changes in the way the heart’s chambers and the arteries in the lungs function. Most of the time, it’s seen in diseases affecting the outer covering of the heart, especially cardiac tamponade (a serious condition where fluid builds up around the heart) and constrictive pericarditis (a long-term inflammation and hardening of the pericardium).

However, it’s necessary to understand that pulsus paradoxus can also happen in heart diseases that don’t involve the pericardium. Examples include a specific type of heart attack that affects the right side of the heart and a type of heart disease where the heart muscles stiffen, restricting the heart’s ability to fill with blood. Furthermore, non-heart related conditions, like serious lung diseases (severe chronic obstructive pulmonary disease, asthma, abnormal buildup of air or fluid in the chest, and lung embolism), conditions that compress the heart (injuries during surgery, severe obesity, and a chest wall deformity called pectus excavatum) can occasionally cause pulsus paradoxus. Lastly, this issue can also arise when a person experiences very severe low blood volume shock.

Early identification of pulsus paradoxus in an emergency department can speed up the diagnosis of cardiac tamponade. Measuring pulsus paradoxus is also beneficial in evaluating the seriousness of an acute asthma attack and how it responds to treatment. Additionally, there are now devices that non-invasively measure variations in blood pressure, improving bedside analysis of pulsus paradoxus.

What Causes Pulsus Paradoxus?

Pulsus paradoxus, a condition where your pulse becomes weaker when you take a deep breath, could be due to a variety of issues related to your heart, lungs, or other conditions. Pulsus paradoxus often occurs in patients who have diseases of the small sac that surrounds the heart, known as the pericardium. Notably, this condition could arise from two types of pericardial diseases: cardiac tamponade, where fluid builds up in the pericardium; and constrictive pericarditis, a hardening or scarring of the pericardium. Other heart-related factors that could lead to this condition include right heart muscle death, or restrictive cardiomyopathy, a condition where the heart becomes stiff and can’t fill with blood properly.

Besides these heart conditions, diseases related to the lungs, including severe chronic obstructive pulmonary disease, asthma, and a life-threatening condition where air enters the chest cavity, known as tension pneumothorax could lead to this condition too. Equally, issues like large amounts of fluid on both sides of the lungs, or a blockage in the lung’s blood vessels can cause pulsus paradoxus. Conditions that result in the heart being squeezed, including accidental injuries during surgery, severe obesity, and a sunken chest, called pectus excavatum, could also contribute to this abnormal pulse.

There are also other heart conditions that might cause a person to experience pulsus paradoxus. These include cardiac tamponade, or when fluid gathers around the heart, heart attack, scarring of the pericardium, heart disease that enlarges the heart, blockage in the lung’s blood vessels, death of the heart’s right ventricle, a congenital heart defect where the valve separating the right chambers of the heart is missing, interruption of the aorta, narrowing of the heart’s mitral valve, and a heart disorder that affects infants and children, causing abnormal thickening of the heart’s inner lining.

People with certain lung conditions can also have pulsus paradoxus. This includes severe asthma, worsening of chronic obstructive pulmonary disease, tension pneumothorax, excessive fluid around the lungs compressing them, and obstructive sleep apnea, a disorder where a person’s breathing stops and starts while sleeping.

Finally, other contributing conditions might include obesity, blockage of the main vein returning blood from the upper body to the heart, hernia of the diaphragm, twisted stomach, and excessive fluid compressing the lungs, obstruction in the opening between the lower neck and armpit, and a large amount of fluid in the abdomen causing it to swell up.

Risk Factors and Frequency for Pulsus Paradoxus

Pulsus paradoxus, a term used in medicine, often appears in patients suffering from various diseases, making it difficult to define its occurrence. Its primary cause, cardiac tamponade, hasn’t been well-documented in medical research, but in a study involving 136 patients with cardiac tamponade, some of the chief causes were identified as follows:

• Cancer: 32%
• Infections: 24%
• Unknown diseases: 16%
• Medical procedure related injury: 15%
• Post-heart attack: 7%
• Uremia (an illness involving the kidneys): 4%
• Others: 2%

Unfortunately, the study didn’t show how many patients developed pulsus paradoxus from these causes. Since little data exists on the frequency of pulsus paradoxus in cardiac tamponade patients, it’s broadly assumed that most such patients exhibit the condition. In one study focusing on 15 patients with cardiac tamponade, over half (10 out of 15, or about 66.6%) had pulsus paradoxus.

Signs and Symptoms of Pulsus Paradoxus

Pulsus paradoxus is a symptom that can indicate different health issues, including a critical condition called cardiac tamponade. Observing pulsus paradoxus can highly suggest the presence of cardiac tamponade, which is likely in more than 80% of cases. However, not seeing this sign does not rule out this condition. If someone shows signs of both pulsus paradoxus and potential tamponade, this requires immediate evaluation for possible medical procedures to drain excess fluid from the heart.

In some situations, cardiac tamponade can happen without the presence of pulsus paradoxus. These situations include:

• Presence of heart issues like internal heart shunts or moderate-to-severe valve problems
• Presence of conditions like severe high blood pressure, aortic stiffness, or complex lung heart disease, which significantly increases heart pressure
• Experiencing an aortic dissection that leads to heart fluid build-up and tamponade
• Presence of hypovolemia, a condition where there is not enough blood in the body, leading to cardiac tamponade

Pulsus paradoxus can show up in a condition called constrictive pericarditis. It can frequently be seen in cases where constrictive pericarditis is combined with pericardial effusion, which is a buildup of fluid around the heart.

Several health conditions unrelated to the pericardium, the sac around the heart, can also lead to pulsus paradoxus. The most common of these conditions include severe asthma or chronic obstructive pulmonary disease. Such conditions generate high pressure within the chest compared to healthy individuals. This pressure can increase the resistance experienced by the left ventricle of the heart and can affect the aorta and other blood vessels. This situation can result in pulsus paradoxus.

When trying to differentiate pulsus paradoxus in pericardial diseases and non-pericardial diseases, it is essential to remember that in non-pericardial diseases, both systolic and diastolic pressures typically decrease. Meanwhile, in pericardial diseases, primarily the systolic pressure decreases with little effect on diastolic pressure, resulting in a narrow pulse pressure.

Testing for Pulsus Paradoxus

You may have heard your doctor mention the term ‘pulsus paradoxus’. This is a medical condition characterized by an exaggerated decrease in systolic blood pressure and pulse wave amplitude during inhalation. Let’s break down how this condition is assessed, and what it might mean for you.

In patients who don’t have an artery being constantly monitored (an indwelling arterial access), the most accurate test for pulsus paradoxus involves a blood pressure cuff and a stethoscope. Digital blood pressure machines can’t measure this condition accurately. First, the doctor will inflate the blood pressure cuff until the heartbeat sound disappears. Then, they gradually deflate the cuff while listening with a stethoscope. The initial heartbeat sounds heard only during exhalation are noted. As the cuff deflates further, the moment when heartbeat sounds are heard during both inhalation and exhalation is also noted. The difference between these two blood pressure readings is what defines pulsus paradoxus.

Highly noticeable pulsus paradoxus may come across as a weakening or even disappearance of the felt pulse during inhalation. In some circumstances, pulsus paradoxus may also affect the reading on a pulse oximeter (a device that measures how rich your blood is in oxygen).

Please note that, during this test, you should continue to breathe normally since your breathing pattern influences the pulsus paradoxus measurement. For instance, if you try to breathe in more deeply due to some lung diseases, it could artificially increase the measurement.

If a patient has an indwelling arterial access, the process is much simpler. The doctors can directly observe the blood pressure changes throughout the breathing cycle on a monitor. Because pulsus paradoxus is due to a drop in the amount of blood pumped out of the heart with each beat, the most noticeable sign would be a decrease in both the top number (systolic) and the pulse pressure (the difference between systolic and diastolic pressures) during the breathing cycle.

Testing for pulsus paradoxus is only one step in the diagnostic process. Your doctor will combine this information with other signs, symptoms, and tests to identify the cause of your condition. If there is suspected or known pooling of fluid around the heart, a condition known as a pericardial effusion, the physician might suspect cardiac tamponade (a serious condition where fluid builds up around the heart). This would trigger additional diagnostic tests such as an ECG (heart rhythm test), chest X-ray, and ultrasound of the heart. If the patient’s blood pressure drops dangerously low, doctors might need to drain the excess fluid from around the heart urgently.

Treatment Options for Pulsus Paradoxus

Pulsus paradoxus is not a disease itself, but an indicator that there could be a serious health problem. It occurs when your blood pressure falls notably during inhalation. The underlying health problem causing pulsus paradoxus should be addressed and treated. If doctors suspect cardiac tamponade, a life-threatening condition caused by fluid buildup around your heart, that’s causing the pulsus paradoxus, immediate treatment is typically required. This often includes a procedure called pericardiocentesis, which involves removing the built-up fluid with a needle. However, if the cause is a tear in the aorta or rupture of the heart muscle (myocardial rupture), surgery is necessary immediately. These conditions are highly serious and need to be treated as emergencies.

If pulsus paradoxus is due to a severe lung disease that’s blocking your airways, immediate treatment would be necessary. This often involves treatment with bronchodilator therapy, which helps open up your airways making it easier for you to breathe, and remedying the specific cause of the lung disease, such as an infection. In case of a tension pneumothorax, a serious condition where air fills the space between your lung and chest wall causing the lung to collapse, immediate treatment is required. This condition is usually treated by freeing the trapped air and creating a small opening or valve in the chest, which is subsequently repaired surgically.

If a fault in a heart valve is causing pulsus paradoxus, a team of heart specialists, including cardiologists or cardiothoracic surgeons, will help develop a treatment plan. This typically involves addressing any underlying heart valve diseases. The plan depends on the patient’s specific health condition.

What else can Pulsus Paradoxus be?

Pulsus paradoxus is a medical condition that signifies there may be an underlying health problem. The causes listed below are some potential explanations for this condition, and medical professionals should keep these in mind when treating a patient with pulsus paradoxus:

• Cardiogenic shock (a severe heart condition that can lead to organ damage)
• Constrictive pericarditis (a condition where inflammation causes the lining around the heart to become thick and rigid)
• Effusive-constrictive pericarditis (a critical heart condition where fluid builds up around the heart)
• Pneumothorax (a collapsed lung)
• Pulmonary embolism (a blockage in one of the pulmonary arteries in your lungs).

What to expect with Pulsus Paradoxus

“Pulsus paradoxus” isn’t a disease by itself. Instead, it’s a medical sign indicating that something else might be wrong. The chances of getting better depend on the underlying condition causing pulsus paradoxus. For instance, pulsus paradoxus caused by a condition known as cardiac tamponade is usually serious and if not treated quickly, can lead to severe outcomes. The earlier the treatment, the better the chances.

Similarly, another condition known as tension pneumothorax can also cause pulsus paradoxus which quickly leads to breathing difficulties, cardiovascular failure, and even death if not recognized and treated on time. Smokers and people with diseases that obstruct their airflow or individuals with AIDS are more likely to have a tension pneumothorax, and it can come back within six months to three years if it was uncomplicated the first time around.

Pulsus paradoxus can also signal a potentially fatal condition known as aortic dissection – a serious condition in which the inner layer of the aorta, the large blood vessel branching off the heart, tears. It has a poor outlook without swift surgical intervention, particularly the Stanford Type A variant. Delaying the surgery can lead to a mortality rate of 50% in the first 48 hours.

Possible Complications When Diagnosed with Pulsus Paradoxus

Recognizing pulsus paradoxus early on during the sickness is important because it could signify a serious base problem or the disease getting worse. Fast treatment of the root cause could avoid the person from getting complications. For instance, a patient with constrictive pericarditis could develop high blood pressure in the lungs, shock, low oxygen levels, kidney failure, and eventually, this could lead to death.

Problems to look out for:

• Pulsus paradoxus, indicating a serious base problem or progression of the disease.
• Constrictive pericarditis leading to various complications:
• High blood pressure in the lungs
• Shock
• Low oxygen levels
• Kidney failure
• Potential death

Preventing Pulsus Paradoxus

Knowing about your overall health and how to spot different disease symptoms can help prevent severe complications from certain illnesses. Additionally, if you have conditions like asthma or chronic obstructive pulmonary disease, consistently following your treatment can lessen the chance that you’ll develop a severe symptom called pulsus paradoxus. Pulsus paradoxus is a condition where a patient’s pulse decreases during inhalation – a sign of serious illness.