INTRODUCTION
The pericardium is the membrane that surrounds the heart and numerous blood vessels depart from it; it is composed of two layers, separated by the pericardial fluid.
Cardiac tamponade is a severe pericardial effusion, which is an abundant collection of fluid in the pericardial cavity that surrounds the heart and severely interferes with its normal pumping function.
Among the symptoms accused by the patient may appear
- Dizziness
- Difficulty in breathing,
- Low blood pressure,
- Increased heart rate
- Cold, sweaty skin,
- Bluish discoloration of the fingers and lips.
Cardiac tamponade requires immediate medical intervention because due to the significant reduction in oxygen availability and the patient can suffer shock, with a fatal outcome.
CAUSE
Male subjects between the ages of 20 and 50 suffer most from cardiac tamponade, but it can also occur in women.
The most common causes of cardiac tamponade are:
- Pericarditis (inflammation of the pericardium)
- Bacterial (e.g. coxiella burnetii) or tuberculous pericarditis,
- Idiopathic (post-viral) pericarditis,
- Viral pericarditis (e.g. hiv ),
- Neoplastic pericarditis,
- Uremic pericarditis,
- Systemic lupus erythematosus,
- Vasculitis (inflammation of the blood vessels)
- Chronic (e.g. behçet’s syndrome ),
- Systemic,
- Pericardial lesion syndromes ( myocardial infarction, pericardiotomy, trauma),
- Secondary metastatic cancers ( lung cancer, breast cancer, lymphoma ),
- Uremia and subsequent myocarditis (inflammation of the heart) with pericardial involvement,
- Interventional cardiology with perforation (ablation, pacemaker insertion, sternal medullary biopsy, pericardiocentesis),
- Acute aortic dissection,
- Traumatic injury of the myocardium (open chest injury),
- Transmural myocardial infarction,
- Ruptured aortic or coronary aneurysm,
- Various rheumatological diseases ( myxedema, hypothyroidism ),
- Radiotherapy (if the patient is subjected to it as a result of a tumor),
- Taking certain medications (minoxidil, isoniazid, hydralazine)
Classification
Cardiac tamponade is classified, based on duration and manifestation, into acute, sub-acute and chronic:
Acute cardiac tamponade: caused by aortic dissection, trauma, complications caused by the introduction of cardiac catheters or pacemakers; on suddenly and manifested by dyspnoea and cardiac pain and, due to the sudden onset, acute cardiac tamponade is life-threatening and requires rapid pericardial drainage;
Sub-acute cardiac tamponade: caused by malignancy, uremia, or idiopathic pericarditis. Onset can be asymptomatic and is usually seen during routine cardiac examinations;
SYMPTOMS
Subacute cardiac tamponade can be asymptomatic, while the more acute forms manifest with:
- Dyspnoea (difficulty in breathing),
- Angina pectoris (severe chest pain accompanied by a sense of tightness),
- Decrease in systolic pressure during inspiration (paradoxical pulse),
- Dizziness _
- Palpitations ,
- Cold, sweaty skin (cold sweating ),
- Tachycardia (increased heart rate ),
- Tachypnea (increased breathing rate ),
- Cyanosis (bluish discoloration of the fingers and lips),
- Pulmonary edema (accumulation of fluid in the lungs),
- Arterial hypotension (decrease in blood pressure),
- Muffled heart tones,
One of the most common and detectable phenomena during cardiac tamponade is that of the paradoxical pulse, i.e. the reduction of systolic pressure beyond the physiological 10 mmHg during the inspiration phase as a consequence of the increase in blood supply in the pulmonary vessels, up to the total disappearance of the pulse during this phase.
Symptoms such as the attenuated perception of heart tones, the reduction of arterial pressure and the increase in central venous pressure are defined as Beck’s triad and the identification of these parameters has diagnostic validity.
The underlying causes of the appearance of these symptoms are related to the amount of accumulated fluid, which is of such an extent that it compresses the heart chambers, causing compromise of the filling of the heart and causing severe complications (which manifest themselves with the symptoms seen):
- Acute circulatory failure (decrease in the amount of blood pumped by the heart),
- A rise in pericardial pressure,
- Paradoxical pulse (a sharp decrease in systolic blood pressure and pulse during inspiration)
- And arterial hypotension (lowering of blood pressure).
Symptoms such as the attenuated perception of heart tones, the reduction of arterial pressure, and the increase in central venous pressure are defined as Beck’s triad and the identification of these parameters has diagnostic validity.
The underlying causes of the appearance of these symptoms are related to the amount of accumulated fluid, which is of such an extent that it compresses the heart chambers, causing compromise of the filling of the heart and causing severe complications (which manifest themselves with the symptoms seen):
- Acute circulatory failure (decrease in the amount of blood pumped by the heart),
- A rise in pericardial pressure,
- Paradoxical pulse (a sharp decrease in systolic blood pressure and pulse during inspiration)
- And arterial hypotension (lowering of blood pressure).
DIAGNOSIS
The three parameters of Beck’s triad are the first sign that can lead the doctor to the diagnosis of cardiac tamponade, however, these three manifestations may not be present simultaneously or are difficult to identify in some contexts such as that of the emergency room; in the same way, even the paradoxical pulse can be very indicative for the doctor, but it is not always easy to identify it (during the diagnosis, the extent of the paradoxical pulse can be quantified with the sphygmomanometer).
Some laboratory tests are associated with the clinical evaluation for diagnostic purposes, such as:
- Electrocardiogram, to identify the drop in voltages and the particular heartbeat caused by cardiac tamponade,
- Echocardiogram (transthoracic bedside echocardiography), to check the aortic and mitral velocity (which decreases during cardiac tamponade) and the speed of tricuspid and pulmonary flows (which, on the other hand, is increased),
- Eco-fast, to evaluate the presence of fluid in the pericardial sac,
- Chest x-ray, with which the enlargement of the cardiac shadow caused by the pericardial effusion can be observed,
- Cardiac catheterization, for measuring atrial pressure,
- Tc
- Coronary angiography, with which the blood flow in the blood vessels is monitored,
- Urinalysis, to check for blood,
- Blood tests to determine the bacterial or viral cause, troponins to evaluate the possibility of myocardial infarction.
The differential diagnosis of cardiac tamponade should be made with:
- Cardiogenic shock,
- Acute right congestive heart failure.
In these cases, unlike cardiac tamponade, the effect of the paradoxical pulse is not evident.
TREATMENT
Cardiac tamponade requires prompt intervention and needs the attention of the emergency room.
It is first of all necessary to administer oxygen to the patient to prevent shock and then, but in any case in a very short time, surgery is carried out to remove the excess fluid (it is sufficient to remove 50-100 ml to ensure an improvement of the symptoms) by means of the pericardiocentesis procedure.
When the infill is at low pressure (less than 10 cl) it is not used, on the contrary, it is not sufficient in the most serious cases, for which a drainage procedure is required which can be:
Covered, by surgical route (through the subxiphoid incision or video-assisted thoracoscopy) or percutaneous, with a needle or balloon catheter. The shunt removes a small portion of the pericardium, proving effective when there is blood and/or clots in the liquid. This procedure allows the wound to be left open in order to administer drugs directly into the pericardial space.
Open, through which the liquid can be completely removed through direct access to the fabric.
Thoracotomy (opening of the chest) with pericardiotomy (incision of the pericardial sac), or the creation of a sub-xiphoid pericardial window is the most recommended treatments when the diagnosis is certain and the danger is confirmed.
Treatment of the primary causes that led to cardiac tamponade is then necessary, as it is a consequence of multiple probable pathologies or cardiac events.