What is Cardiac Tamponade?
Cardiac tamponade is a serious emergency often caused by a medical issue or injury. It occurs when too much fluid builds up in the sac surrounding the heart, putting pressure on it and reducing its ability to pump blood, which can lead to shock. Recognizing and diagnosing cardiac tamponade quickly is crucial to prevent a complete cardiovascular breakdown and heart stoppage. Treatment can be done either near the patient’s bed or in an operating room.
What Causes Cardiac Tamponade?
Cardiac tamponade, a serious medical condition, occurs when there’s a buildup of fluid around the heart. This accumulation can occur for many reasons. For instance, if a person has a heart injury or a major heart attack, the bleeding can cause a rapid increase in fluid around the heart. However, other factors that gradually increase the fluid include infections (like tuberculosis or myocarditis), autoimmune diseases, tumors, kidney failure, and inflammation of the heart’s outer lining.
Interestingly, the body tends to handle a slow buildup of fluid better than swift accumulations. Therefore, when the build-up is due to a traumatic event (like an injury), it only requires a small amount of fluid to cause instability in the body’s blood circulation. On the other hand, non-injury related causes, like tumors, may allow a substantial amount of fluid to amass around the heart before a person shows symptoms.
Risk Factors and Frequency for Cardiac Tamponade
The exact number of people who have pericardial effusion, a condition where there’s excess fluid around the heart, is not fully known. However, we do know that certain groups of people are more likely to have it. These include:
- People who are HIV-positive
- Patients with end-stage kidney disease
- People who have or may have cancer
- Individuals with a history of congestive heart failure
- People who have had tuberculosis
- Those with autoimmune diseases like lupus
- Individuals who have had penetrating injuries to the chest
Signs and Symptoms of Cardiac Tamponade
Cardiac tamponade is a serious medical condition where fluid accumulates around the heart, restricting its function. People with this condition often have symptoms similar to other heart-related issues. These might include vague chest pain, a racing heart, difficulty breathing, or even more severe symptoms like dizziness, fainting, and confusion. In some cases, they might experience cardiac arrest with a still-functioning electrical heart activity.
Classic signs of cardiac tamponade, known as Beck’s triad, are low blood pressure, swelling of veins in the neck, and muffled heart sounds. An important symptom that suggests a cardiac tamponade is Pulsus paradoxus, which is a significant drop in blood pressure during inhalation. However, it’s worth noting that Pulsus paradoxus might not be present in all patients, particularly those with atrial septal defects, high diastolic pressures, pulmonary hypertension, and aortic valve issues.
Patients may also show:
- Kussmaul sign — an unusual rise in neck vein pressure and swelling during inhalation
- Ewart sign — a patch of dullness and abnormal lung sounds below the left shoulder blade in patients with large fluid collections around the heart
- Absent ‘y’ descent in neck vein pulse tracing due to the high pressure inside the sack around the heart that hampers the filling of the heart’s ventricles
The excessive fluid around the heart weakens its function. It prevents the heart from filling properly, leading to a decline in the stroke volume (amount of blood pumped out of the heart). However, diagnosing a tamponade merely based on these clinical signs can be challenging, as they are not always precise or specific.
Testing for Cardiac Tamponade
When a doctor thinks a patient might have cardiac tamponade, a condition where fluid in the pericardium (the sac around your heart) builds up and affects the heart’s functioning, there are several methods they might use to confirm this suspicion.
For starters, they might do an ECG, short for electrocardiogram, which is a test that measures the electrical activity of your heart. Certain results, such as low voltages or electrical alternans (a rare finding where the heart ‘swings’ due to the fluid accumulation), might point towards cardiac tamponade. However, most of the time, the ECG might just show a condition called sinus tachycardia, which is basically an increased heart rate.
Another tool doctors might use is a chest x-ray, which can show if the heart is enlarged and even hint at pericardial effusion (fluid accumulation in the heart sac) if other x-rays of the patient’s chest are available for comparison. A scan called the CT chest can also detect this fluid accumulation.
One of the best imaging methods, however, is echocardiography. This test uses sound waves to create detailed pictures of your heart. It’s powerful because it can not only confirm the presence of pericardial effusion but also determine its size and any impact it might be having on the heart’s performance. Moreover, even healthcare professionals who are not heart specialists can use this tool to answer specific questions about the heart, such as if there is a significant amount of fluid in the heart sac.
Lastly, various blood tests can also aid the diagnosis. These include checks for levels of creatine kinase (an enzyme), renal profile (kidney function), coagulation profile (blood clotting), antinuclear antibody tests (to identify autoimmune disorders), ESR (a marker of inflammation), HIV testing and a PPD skin test (for tuberculosis).
Treatment Options for Cardiac Tamponade
Before jumping to relieve pressure on the heart, it’s important for the patient to first get oxygen, receive fluids, and rest in bed with their legs raised. It’s also suggested to avoid using a ventilator if possible, as it might lower the amount of blood returning to the heart and worsen symptoms.
The usual treatment for heart tamponade, a life-threatening medical condition, is to remove the fluid building up around the heart. This relieves the pressure on the heart. This can be done by a medical procedure called needle pericardiocentesis. This procedure, often done at the patient’s bedside, uses a needle to drain the fluid. It can be done either using traditional markers to guide the needle or with the help of a bedside ultrasound to guide the needle in real-time. Even removing a small amount of fluid can greatly improve the patient’s condition. Sometimes, a tube is left in place to allow for further fluid drainage.
Surgery could also be considered, like creating a small opening in the pericardium or removing it entirely. In cases of traumatic heart arrests where heart tamponade is suspected, another option is to perform an emergency resuscitative thoracotomy. This involves making an incision in the chest and opening the pericardial sac. These surgical options are usually preferred over needle pericardiocentesis for traumatic cases.
While using fluids and pressure support can be helpful, these are temporary solutions. They should be used as a bridge while preparing for a definitive treatment, as described above.
What else can Cardiac Tamponade be?
- Fluid buildup around the lungs (Pleural effusion)
- Air leak into the area between the lung and the chest wall (Pneumothorax)
- Blockage in one of the pulmonary arteries in the lungs (Pulmonary embolism)
- Hardening or thickening of the heart’s protective sac (Constrictive pericarditis)
- Condition where the heart doesn’t pump blood as well as it should (Heart failure)
- Sudden drop in blood flow through the body (Shock)
What to expect with Cardiac Tamponade
Cardiac tamponade is a critical medical condition that can be fatal without proper treatment. The timing of treatment is crucial; if it’s delayed, the patient’s condition can worsen dramatically. If cardiac tamponade is caused by a malignant disease, more than 75% of patients may not survive beyond 12 months.
