Presenting Problems in Cardiovascular Disease

Cardiac Tamponade

Dr Aadarsh Yadav26th December 2019

What is cardiac tamponade?

Cardiac tamponade is the decompensated phase of cardiac compression resulting from an unchecked increase in pericardial fluid pressure. Tamponade may be slow to develop, owing to quiet effusion, or sudden, usually due to bleeding.

In either case, compression of the heart must be relieved by drainage. Clinically, patients have signs of low-output state, including air hunger, which often resembles congestive heart failure, but without pulmonary oedema.

There is an equalization of diastolic pressure throughout the heart. Pulsus paradoxus, a drop in systolic blood pressure greater than ten mmHg during regular inspiration, is usual. Imagining, particularly Doppler echocardiography, usually shows right ventricular and/or diastolic atrial collapse, and occasionally left arterial failure and a swinging heart.

In volume-expanded patients, chamber collapses may not be present, whereas hypovolemia can produce destruction without cardiac tamponade.

Pathophysiology

The heart is enclosed in a tough sac called the ‘pericardium’.

This inelastic pericardium is tough, and fibrous on the outside, whereas its inner surface is lined with a glistening layer, the ‘parietal layer’ of the pericardium. This parietal layer is reflected on to the heart as the ‘visceral layer’ of the serous pericardium.

Between the two opposing layers of the parietal and serous pericardium exists a thin, slit-like cavity, called the ‘pericardial cavity’. This cavity contains a thin layer of fluid, the ‘pericardial fluid’ which is required to keep the heart in a friction-free environment and to allow it to beat freely.

When an excessive amount of fluid gets accumulated in the pericardial cavity (normal value is 50 mL), due to infection, inflammation, or any other causes, a pericardial effusion develops, which causes the sac to become constricted, thus depriving the heart of expanding fully, and limiting, or reducing the amount of blood flow that the heart normally receives.

This sudden elevated pericardial pressure causes a significant burden to be placed on the heart, which causes a decrease in the diastolic filling of the ventricles, and a resultant decreased stroke volume.
This is a potentially lethal condition, and death may occur within seconds if interventions are not made.

Changes occurring in the heart

A series of changes occur in the heart during this tamponade:

• The volume of the pericardial sac is compromised.
• Pericardial cavity gets filled up with fluid faster than it can adapt, or stretch according to the increasing load on it,
  Diastolic filling of the heart is impaired.
• Diastolic filling of the heart is impaired.
• Decreased diastolic filling leads to decreased stroke volume, and ultimately, decreased cardiac volume.
• Decreased stroke volume may give rise to obstructive shock, which proceeds to cardiac arrest, and ultimately death, if not treated immediately.
• There is a marked elevation, and then subsequent equalization of pressures in the right and left ventricles, right and left atriums, pulmonary artery and the pericardium.
• Additionally, the veins of the head and neck become engorged because of the backup of blood, thus giving rise to the distended jugular veins in the side of the neck, which is a characteristic finding.

Sign and symptoms

The symptoms are as follow:

• Central, compressive or squeezing chest pain radiating to neck, left jaw, or left shoulder
• Restlessness and anxiety
• Weakness
• Shortness of breath
• Lightheadedness
• cough
• Fainting
• Dizziness
• Loss of consciousness

READ – 12 scary signs of the tamponade

Signs

Signs typically includes

• Hypotension
• Tachycardia
• Tachypnoea
• Dyspnoea
• Cardiogenic shocks

Causes 

It is incited by the buildup of fluid inside the pericardium, i.e., massive or uncontrolled pericardial effusion. The objectives of accumulation of fluid inside the pericardium might include: 

• Flinty Chest trauma
• Pericarditis (inflammation of the pericardium)
• Kidney failure
• Hypothyroidism
• Aortic rupture
• Myocardial Infraction
• Bacterial infection
• Tuberculosis
• Gunshot or stab wounds
• Any blunt trauma to the chest from a Road traffic accident or industrial accident
• Unintended perforation after a cardiac catheterization, angiography, or during insertion of a pacemaker
• Cancer metastasized to the pericardial sac, such as breast or bronchogenic carcinoma 
• Lupus, an autoimmune disease
• Altitudinous levels of radiation to the chest
• Complications of cardiac surgery or cardiac-thoracic surgery

READ – Cardiac tamponade vs pericardial effusion

Diagnosis 

The diagnosis is made by the general examination, cardiovascular system examination, and investigations. Three sign is mainly found in the tamponade, which is known as Beck’s triad. They include

• Low blood pressure (hypotension)
• Jugular venous distension (raised neck vein) 
• Rapid heartbeat (tachycardia) with muffled heart sounds

The physician may found another sign too. Other signs may include Pulsus Pradoxus during pulse examinations. This examination is not sufficient for the confirmatory diagnosis. Your physician will conduct further tests to authenticate a diagnosis. 

One such investigation is an echocardiogram, which is known as an ultrasound of the heart. It can distinguish whether the pericardium is expanded and if the ventricle has collapsed due to low blood volume. Your physician can detect ST-segment changes n the electrocardiogram (ECG), which may also show low voltage QRS complexes. 

The chest x-ray is also done to see whether the heart is abnormally enlarged or the presence of any unusual shape of the heart due to fluid buildup. Ct scan is also done to confirm the presence of extra fluid in the pericardium. A magnetic resonance angiogram is also done to see how blood is flowing through your heart. 

Your physician may also advise going for blood tests to measure the levels of the total count of RBCs, TC, and DC of WBCs. Blood tests may even recognize higher levels of cardiac enzymes that the body release in response to the damage to the cardiac muscle. 

Differential Diagnosis

The possible differential diagnosis of this tamponade includes:

• Pleural effusions
• Tension Pneumothorax
• Pulmonary embolism
• Shock

Treatment 

It is a medical crisis that requires immediate hospitalization. The initial treatment is usually supportive treatment, which includes the administration of oxygen and monitoring of vital signs. The favourable treatment involves your doctor making sure you’re stabilized. There are two primary purposes for it’s treatment.

1. The first one is that it should relieve pressure on your heart.
2. The second one is the treatment of the underlying causes. 

The treatment involves the draining of excess fluid from around the heart. A doctor may use the following procedure to remove the fluid and debase the pressure on the heart: 

• Pericardiocentesis: It is the process of removal of fluid from the pericardium applying a needle. 
• Pericardiectomy: The surgical eviction of part of the pericardium. It is done to relieve heaviness on the heart. 
• Thoracotomy: A surgical manoeuvre that allows the draining of blood or blood clots around the heart. 

However, more Daedalian cases will often require surgery, including thoracotomy. 

Here is the crucial role of the cardiac tamponade ECG nowadays

History of it’s surgery

Dr. Luther Hill was the aboriginal American to address the successful rectify of a cardiac wound in a 13-year-old boy who was a fatality of multiple stab wounds. When the first doctor entered, the boy was in absolute shock. The doctor evoked that Dr Luther Hill had spoken on the subject of repair of the cardiac wounds at a civic, medical society meeting in Montogomery, Alabama.

With the comply of the boy’s parents, Dr, Hill was sent for. He disembarked sometime after the dead of night with six other physicians. One was his brother — the surgery abode on the patient’s kitchen table in a run-down shack. Lightning was provided by two kerosene lamps borrowed from neighbours. 

One physician-administered chloroform anaesthesia. The boy was adversity from this tamponade as an aftermath of a stab wound to the left ventricle. The stab anguish to the ventricle was with the help of two catgut sutures.

Although the early postoperative period was stormy, the boy made an exhaustive recovery. The Refurbished patient, Henry Myrick, sooner moved to Chicago, where, in 1942, at the age of 53, he got into a heated crusher and was stabbed in the heart again, very close to the original stab wound. This time, Henry was not lucky and died from the injury. 

Surgery 

One of the most bourgeois settings for the tamponade is in the first 24 to 48 hours after heart surgery. After the heart surgery, chest tubes are implanted to drain blood. These chest tubes, however, are fain to clot formation. When a chest tube becomes impeded or plugged, the blood that should be removed can cumulate around the heart, leading to tamponade. 

Once the tamponade is under curb and your condition stabilizes, your doctor may perform additional investigations to determine the underlying cause of your circumstances. 

Do you know what diastolic heart failure is?

Prevention 

It is not achievable to prevent all cases of the tamponade. However, people can reduce their modifiable risk factors by doing the following: 

Avoiding cigarette smoking 

• Attending routine medical checkups
• Having a heart-healthy diet and cardiac exercise to promote good heart health.
• Reducing divulgence to bacterial or viral infections.
• Receiving treatment for hypothyroidism and lupus.
• Maintaining proper kidney health by regular checkups and drinking enough water. 

End of the line

It is an arduous medical condition which requires immediate medical hospitalization. Tamponade is an uncommon but severe that can result in shock or death. The frequency of tamponade is unclear. One estimate from the united states places it at 2 per 10,000 per year. It is estimated to occur in 2% of those with stab or gunshot wounds to the chest. 

People who receive a vigilant diagnosis and available treatment generally have a better likelihood. Although it is not feasible to prevent all the cases of the tamponade, people should be conscious of both modifiable and non-modifiable risk factors. People should also altercate preventive methods with their doctors. 

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Summary & Key Points

1. It is a medical emergency and needs to be treated immediately.
2. It occurs when the pericardial fluid level rises above 200 ml rapidly, or 2000 ml slowly in the pericardial cavity.
3. The 3 cardinal signs specific for the tamponade are: Decreased heart sounds, decreased blood pressure, and distended jugular veins (collectively known as Beck’s triad).
4. Cardiomegaly is seen on a chest x-ray.
5. ECG findings include sinus tachycardia, electrical Alternans, and low voltages.
6. A percutaneous pericardiocentesis is indicated for almost all the patients as the initial treatment in acute emergencies.
7. In serious patients, a thoracotomy is performed.

Self-Assessment Quiz

1. Which of the following factors will help a doctor assess whether his recently operated patient is suffering from this tamponade?

a) Elevated JVP
b) Bradycardia
c) Hypertension
d) Increased heart sounds on auscultation

Key: A

2. Which of the following factors may contribute to give rise to the tamponade emergency?

a) Severe cough and asthma
b) A gunshot on the chest
c) Lower limb injury
d) Paralysis

Key: B

3. What is the most common cause of this tamponade?

a) Diabetes
b) Old Age
c) Pericardial Effusion
d) Hypertension

Key: C

4. What is the first-line investigation for diagnosing a cardiac tamponade?

a) Chest X-ray
b) Cardiac Catheterization
c) ECG (or EKG)
d) CBC, ESR, etc.

Key: C

5. A 20-year male presented to the emergency ward 2 weeks following a cardiac surgery. He complains of experiencing symptoms of shortness of breath, dizziness and distended veins in the neck. What is the most likely diagnosis?

a) Myocardial Infarction
b) Cardiac Tamponade
c) Post-surgical complications
d) Heart Failure

Key: B

6) Which of the following factors are not specific findings of this tamponade?

a) Hypertension
b) Tachycardia
c) Collapse
d) Pulsus paradoxus

Key: A

7) The final treatment option indicated for a serious patient with this tamponade is:

a) Percutaneous pericardiocentesis
b) Improving oxygen saturation levels
c) Start antihypertensive drugs
d) Thoracotomy

Key: D

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