cardiac tamponade

Cardiac Tamponade

Definition

Cardiac tamponade occurs when the heart is squeezed by fluid that collects inside the sac that surrounds it.

Description

The heart is surrounded by a sac called the pericardium. When this sac becomes filled with fluid, the liquid presses on the heart, preventing the lower chambers of the heart from properly filling with blood.

Because the lower chambers (the ventricles) cannot fill with the correct amount of blood, less than normal amounts of blood reach the lungs and the rest of the body. This condition is very serious and can be fatal if not treated.

Causes and symptoms

Fluid can collect inside the pericardium and compress the heart when the kidneys do not properly remove waste from the blood, when the pericardium swells from unknown causes, from infection, or when the pericardium is damaged by cancer. Blunt or penetrating injury from trauma to the chest or heart can also result in cardiac tamponade when large amounts of blood fill the pericardium. Tamponade can also occur during heart surgery.

When the heart is compressed by the surrounding fluid, three conditions occur: a reduced amount of blood is pumped to the body by the heart, the lower chambers of the ventricles are filled with a less than normal amount of blood, and higher than normal blood pressures occur inside the heart, caused by the pressure of the fluid pushing in on the heart from the outside.

When tamponade occurs because of trauma, the sound of the heart beats can become faint, and the blood pressure in the arteries decreases, while the blood pressure in the veins increases.

In cases of tamponade caused by more slowly developing diseases, shortness of breath, a feeling of tightness in the chest, increased blood pressure in the large veins in the neck (the jugular veins), weight gain, and fluid retention by the body can occur.

Diagnosis

When cardiac tamponade is suspected, accurate diagnosis can be life-saving. The most accurate way to identify this condition is by using a test called an echocardiogram. This test uses sound waves to create an image of the heart and its surrounding sac, making it easy to visualize any fluid that has collected inside the sac.

Treatment

If the abnormal fluid buildup in the pericardial sac is caused by cancer or kidney disease, drugs used to treat these conditions can help lessen the amount of fluid collecting inside the sac. Drugs that help maintain normal blood pressure throughout the body can also help this condition; however, these drugs are only a temporary treatment. The fluid within the pericardium must be drained out to reduce the pressure on the heart and restore proper heart pumping.

The fluid inside the pericardium is drained by inserting a needle through the chest and into the sac itself. This allows the fluid to flow out of the sac, relieving the abnormal pressure on the heart. This procedure is called pericardiocentesis. In severe cases, a tube (catheter) can be inserted into the sac or a section of the sac can be surgically cut away to allow for more drainage.

Prognosis

This condition is life-threatening. However, drug treatments can be helpful, and surgical treatments can successfully drain the trapped fluid, though it may reaccumulate. Some risk of death exists with surgical drainage of the accumulated fluid.

Resources

Organizations

American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300. http://www.americanheart.org.

Key terms

Pericardiocentesis — A procedure used to drain fluid out of the sac surrounding the heart. This is done by inserting a needle through the chest and into the sac.

tamponade /tam·pon·ade/ (tam″po-nād´)

1. surgical use of a tampon.

2. pathologic compression of a part.

balloon tamponade esophagogastric tamponade by means of a device with a triple-lumen tube and two inflatable balloons, the third lumen providing for aspiration of blood clots.

cardiac tamponade compression of the heart caused by increased intrapericardial pressure due to collection of blood or fluid in the pericardium.

esophagogastric tamponade the exertion of direct pressure against bleeding esophageal varices by insertion of a tube with a balloon in the esophagus and one in the stomach and inflating them.

Esophagogastric tamponade, using Sengstaken-Blakemore tube.

cardiac tamponade

Compression of venous return to the heart because of increased volume of fluid in the pericardium.

cardiac tamponade

[tam′pənäd′]

compression of the heart produced by the accumulation of blood or other fluid in the pericardial sac. Also called cardiac compression, pericardial tamponade.

observations Signs of cardiac tamponade may include distended neck veins, hypotension, decreased heart sounds, tachypnea, peripheral pulses that are weak or absent or that fall sharply during inspiration (pulsus paradoxus), reduced left atrial pressure, and pericardial friction rub. The patient, who is usually anxious and restless, may sit upright or lean forward, and the skin may be pale, dusky, or cyanotic. The electrocardiogram generally shows decreased cardiac voltage and may show electrical alternans, and the chest x-ray film may reveal an enlarged heart shadow ("water bottle" heart).

interventions The patient is maintained on bed rest; the head of the bed is elevated 45 degrees, and a defibrillator and emergency drugs are kept at the bedside. IV saline is the initial therapy of choice to maintain filling pressures in the heart. Blood pressure, respiration, apical pulse, and atrial and pulmonary wedge pressures are checked every 15 to 30 minutes. Auscultation for pulsus paradoxus is performed, and peripheral pulses are checked every 30 minutes. A 12-lead electrocardiogram is usually ordered, and the patient is placed on a cardiac monitor with the rhythm strip checked every hour. A Doppler echocardiogram is done initially and may be repeated a few days later. Cardiotonic and antiarrhythmic drugs are administered as ordered. Aspiration of the fluid in the pericardial sac (pericardiocentesis) is performed, and, if surgery is indicated, the patient is prepared for the procedure. In cases in which bleeding vessels are the cause of the tamponade, the vessels are ligated.

Cardiac tamponade

tamponade [tam″po-nād´]

1. surgical use of a tampon.

2. pathologic compression of a part.

cardiac tamponade compression of the heart due to collection of fluid or blood in the pericardium. It may be either chronic or acute. Chronic cardiac tamponade occurs when fluid slowly enters the pericardial sac, allowing time for the membrane's expansion to accommodate the fluid, which can be as much as 1 liter. This gradual filling may or may not produce changes in cardiac hemodynamics. However, if there is rapid filling of the pericardial sac, as little as 200 ml can precipitate a life-threatening emergency. The ultimate effect of cardiac tamponade is reduced cardiac output and inadequate tissue perfusion.

Causes of acute cardiac tamponade include pericarditis with effusion of serosanguineous fluid into the sac, and either surgical or accidental trauma with leakage of blood into the sac. Occasionally, anticoagulant therapy can lead to extensive bleeding around the heart and cardiac tamponade.

Excessive fluid within the pericardial sac causes pressure against the cardiac structures, interferes with ventricular and atrial filling, and compromises blood supply to the myocardium via the coronary vessels. These conditions occur because of the following events: The compressed atria cannot fill as they normally would and so less blood is available for the ventricles; thus preload (the volume of blood in the ventricles at the end of diastole) is reduced. Ventricular filling is further impaired by compression of the ventricles. As pressure within the ventricles rises because of tamponade, pressure differences between the atria and ventricles are reduced, causing the valves between the two chambers to close before the ventricles have had time to fill completely. Increasing pressure within the heart chambers and in the pericardium impinges on the coronary arteries and veins, reducing blood supply to the myocardium, slowing contractility, and further reducing cardiac output.

Clinical features of cardiac tamponade include increased central venous pressure, falling arterial blood pressure, tachycardia, faint or muffled heart sounds, a narrowing pulse pressure, and an exaggerated inspiratory fall in systolic blood pressure (pulsus paradoxus). Hypoxia of cerebral tissues can produce confusion, restlessness, agitation, panic, and a sense of impending doom. Peripheral hypoxia is signaled by changes in the color, temperature, and excessive sweating.

Diagnosis can be confirmed by echocardiography and other radiologic studies. However, if the situation is acute, these tests cannot be done without endangering the life of the patient; thus diagnosis must be based on clinical findings. Once tamponade is suspected, fluids are administered and a pericardiocentesis is done to remove the compressing fluid.

Pericardiocentesis is performed to remove compressing fluid in cardiac tamponade. From Polaski and Tatro, 1996.

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cardiac compression coronary coronary arteries coronary perfusion pressure Kussmaul sign Kussmaul's sign mechanism of death oncologic emergencies paradoxic pulse pectoral pectoralis pericardial tamponade pericardicentesis pericardiocentesis pericarditis pulsus paradoxus Swan-Ganz catheterization Swinging Heart tamponade			She was, however, unable to render a satisfactory explanation as to why she destroyed her informal notes, and wonder of wonders, failed to make any entries on a patient's chart whose heart stopped due to cardiac tamponade. Why did nurse fail to chart & destroy her notes? by Tammelleo, A. David / Nursing Law's Regan Report 4) Rarer complications include pericardial injury, resulting in cardiac tamponade. Aortoesophageal fistula: a case report by Tighe, David; Wood, Andy; Kale, Savita / Ear, Nose and Throat Journal 21 End-tidal carbon dioxide monitoring is important, and if insufflation is used to collapse the isolated lung, insufflation pressures should be kept below 10 to 15 mmHg, so as to avoid mediastinal compression and subsequent cardiac tamponade and possible circulatory collapse, particularly in hypovolaemic patients. Review article: Approach-related complications of open versus ... by K M C Cheung and S Al Ghazi / Journal of Orthopaedic Surgery			cardiac notch cardiac nuclear scanning cardiac opening cardiac output cardiac pacemaker cardiac pain cardiac plexus cardiac precautions cardiac profile guideline cardiac pump effectiveness cardiac radionuclide imaging cardiac reflex cardiac regurgitation cardiac rehabilitation cardiac reserve cardiac rhythm cardiac risk evaluation panel Cardiac shunt cardiac souffle cardiac sound cardiac sphincter cardiac standstill cardiac stenosis cardiac stimulant cardiac syncope cardiac tamponade cardiac thrombosis cardiac valve cardial notch cardialgia cardiasthenia cardiectasia cardiectasis cardiectomy cardiectopia Cardigan Welsh corgi cardinal cardinal flower cardinal frontal plane cardinal horizontal plane cardinal ligament cardinal movements of labor cardinal point cardinal position of gaze cardinal rotation cardinal sagittal plane cardinal signs cardinal symptom cardinal veins Cardinal’s Cap carding			cardiac sodium channels cardiac souffle cardiac souffle cardiac sound Cardiac sounds Cardiac Source of Embolism cardiac sphincter cardiac sphincter cardiac sphincter cardiac standstill cardiac stenosis Cardiac Step Down Unit cardiac stimulant Cardiac stress test cardiac stroke volume cardiac stroke volume cardiac stroke volume Cardiac surgeon Cardiac surgery Cardiac surgery Cardiac surgery Cardiac Surgery and Transplantation Research Center Cardiac Surgery Intensive Care Unit Cardiac Surgery Unit Cardiac Surgery with Extracorporal Circulation Cardiac Sympathetic Afferent Nerves Cardiac Sympathetic Nervous Function cardiac syncope cardiac syncope cardiac syncope cardiac tamponade cardiac tamponades cardiac tamponades cardiac tamponades cardiac thrill cardiac thrill cardiac thrill cardiac thrombosis Cardiac toxicity Cardiac transplant Cardiac Transplant Research Database Cardiac transplantation Cardiac transplantation Cardiac Treadmill Exercise Stress Testing Cardiac tumor Cardiac tumour Cardiac Ultrasound Laboratory cardiac v cardiac v cardiac v cardiac v's cardiac v's cardiac v's Cardiac Vagal Afferent Stimulation Cardiac Vagal Efferent Nerve Activity Cardiac Vagal Nerve Activity cardiac valve cardiac valve cardiac valve cardiac valve fenestration cardiac valve fenestration