Pericardiocentesis and Pericardial Intervention

Introduction

Pericardial disease reflects a wide range of clinical presentations and pathologies, from acute pericarditis to cardiac tamponade. Unlike coronary artery disease, heart failure, or valvular heart disease, however, there are few randomized clinical trial data to guide physicians and interventionalists in its management. There are currently no American College of Cardiology guidelines on management of pericardial disease, with only European Society of Cardiology guidelines available to aid in the diagnosis and management of these conditions.

The clinical presentations of pericardial effusions are variable, with some patients being completely asymptomatic while others develop cardiac tamponade and hemodynamic collapse. Pericardiocentesis is a catheter-based technique utilizing a needle to aspirate the pericardial fluid, usually under electrocardiographic (EKG), fluoroscopic, and/or echocardiographic guidance. Percutaneous balloon pericardiotomy is a relatively novel catheter-based technique that offers patients a less invasive technique than conventional surgical pericardial window to relieve recurrent pericardial effusions or malignant effusions. Improvements in the technique to access the pericardial space, and the concomitant use of pericardioscopy, have led to the development of a number of novel interventional techniques over the past two decades to perform a number of procedures: from percutaneous biopsy of the percardium, to epicardial electrophysiological ablation procedures, and most recently, percutaneous ligation of the left atrial appen­dage as a method of stroke prevention in individuals with permanent atrial fibrillation in whom anticoagulation is contraindicated.

These pericardial techniques, their indications and supporting clinical evidence, and procedural complications will be discussed in detail in this chapter.

The Normal Pericardium

The pericardium is a relatively avascular fibroelastic sac that surrounds the heart and is composed of two layers: a visceral and a parietal layer separated by a potential space containing 15 mL to 35 mL of straw-colored serous fluid. The visceral pericardium is composed of a single layer of mesothelial cells adherent to the myocardial surface. The parietal pericardium is a fibrous structure composed primarily of collagen and a lesser amount of elastin.

As a result of its fibrous inelastic qualities, the normal pericardium has a relatively steep pressure-volume curve. It is distensible when the intrapericardial volume is small but becomes gradually inextensible when the volume increases. In the presence of a pericardial effusion, the intrapericardial pressure depends on the relationship between the absolute volume of the effusion, the speed of accumulation of the fluid, and the intrinsic pericardial elasticity. Therefore, the clinical presentation of pericardial effusion depends not only on the volume of the effusion, but also on the rapidity of fluid accumulation.

Pericardial Effusion and Tamponade

Pericardial effusion may result from a variety of clinical conditions (see Table 35-1 ). Transudative fluids result from obstruction of fluid drainage through lymphatic channels. Exudative fluids occur secondary to inflammatory, infectious, malignant, or autoimmune processes. The frequency of specific etiologies varies greatly based on geography. In developed countries, both malignancy and infection are the most common causes of pericardial effusion. A pericardial effusion is associated with a known systemic disease in approximately 60% of cases.

Pericardial effusions may be asymptomatic or manifest a wide range of clinical symptoms. Patients can report pericarditis-related chest pain, which is typically relieved by sitting up and worsened by lying supine and deep breathing. They may report palpitations most frequently due to atrial arrhythmias. They may manifest generalized symptoms such as dyspnea and cough, presyncope or syncope, dysphagia, abdominal fullness, anxiety, cyanosis, and fever. Large pericardial effusions in the absence of inflammatory signs and symptoms are often neoplastic.

Cardiac tamponade is a life-threatening condition that results from the accumulation of intrapericardial fluid that impairs ventricular diastolic filling. Ultimately, cardiac chambers are compressed and fail to fill when their pressures are exceeded by the intrapericardial pressure. Because of their lower pressures, the right heart chambers are more prone to compression. The intrapericardial pressure depends on the volume of the effusion, the speed of accumulation, and the pericardial elasticity. Rapidly accumulating effusions result in cardiac tamponade at relatively small volumes because the pericardium does not have adequate time to stretch. When effusions accumulate slowly, pericardial compliance gradually increases, allowing the pericardium to accommodate large volumes (as much as 2 to 3 L). Malignancy is the most common cause of pericardial effusion with tamponade (~50%).

In all cases of cardiac tamponade, the initial treatment consists of removing pericardial fluid by prompt pericar­diocentesis and drainage. Reaccumulation is common, especially in malignant effusions, and is traditionally an indication for surgical pericardial window. Autopsy and surgical stud­ies have demonstrated myocardial or pericardial metastatic deposits in approximately 50% of patients presenting with malignant effusion-related cardiac tamponade. Although the short-term survival of patients with tamponade depends on its early diagnosis and prompt treatment, long-term survival is dictated by the prognosis of the underlying primary illness, regardless of the surgical technique or interventional procedure performed.

Clinical Diagnosis of Pericardial Tamponade

Clinical findings suggestive of pericardial tamponade include:

• Beck's triad of tamponade: hypotension, distant heart sounds, jugular venous distention.

• Pulsus paradoxus: A decrease in systolic blood pressure of more than 10 mm Hg with inspiration due to a reduction in cardiac output during inspiration. With inspiration, negative intrathoracic pressures increase venous return and filling of the right-sided chambers. The interventricular septum consequently bows to the left, reducing left ventricular filling and output. This is quantified during the physical examination using a manual sphygmomanometer cuff during normal respirations by listening for Korotkoff sounds. As the cuff pressure is slowly reduced, Korotkoff sounds will initially be intermittent and become continuous with further reduction in the cuff pressure. The difference in the pressure measurement at which Korotkoff sounds are first audible and become continuous define the pulsus.

• Elevated jugular venous pressure with loss of the Y descent of the jugular venous pulse.

A pericardial friction rub is associated with acute peri­carditis and can occur with effusions. This high-pitched, scratching sound is best auscultated at the left lower sternal border with the patient leaning forward. A rub typically consists of three components, namely, ventricular systole, ventricular diastole, and atrial systole. Frequently, only one or two of the components are audible. Additionally, the patient may demonstrate tachycardia and tachypnea and have signs of venous congestion with ascites, hepatosplenomegaly, and lower extremity edema.

On the EKG, pericarditis with an effusion may produce typical EKG changes:

• Widespread ST-segment elevation (>25% of the height of the T-wave)

• PR depression (elevation is often seen in lead aVR)

• Low voltage can be indicative of a large pericardial effusion

• Electrical alternans may result as the heart swings within a large pericardial effusion.

Indications for Pericardiocentesis

Pericardiocentesis is the technique of catheter-based aspiration and drainage of pericardial fluid. It may serve both as a diagnostic and potentially therapeutic procedure in patients with pericarditis with pericardial effusion, chronic pericardial effusion, effusive-constrictive pericardial effusion, and pericardial effusion with cardiac tamponade.

Many asymptomatic large pericardial effusions do not require pericardiocentesis by themselves if they do not produce hemodynamic compromise, unless there is a need to perform fluid analysis to aid diagnosis. The yield of pericardial fluid analysis in determining the cause of pericardial effusion is low. Prospective long-term follow-up of patients with large idiopathic chronic pericardial effusions has demonstrated that these effusions can be well tolerated for long periods in the majority of cases, although the risk of developing tamponade is unpredictable. Although pericardiocentesis may be effective at draining the fluid collection, it frequently reaccumulates. Therefore, in this situation, it is recommended that the patients be considered for early definitive pericardiotomy or pericardial window creation.

In patients with pretamponade or overt cardiac tamponade, emergency drainage of pericardial fluid is a life-saving therapy, avoiding hemodynamic collapse and cardiac arrest with pulseless electrical activity. In situations of impending circulatory collapse or overt tamponade, pericardiocentesis can be performed blindly using anatomic landmarks, but in more stable circumstances, it is advisable to ultilize EKG, echocardiographic, and fluoroscopic guidance.

When performing pericardiocentesis, several objectives should be achieved:

• 1.

  Relief of tamponade, if present

• 2.

  Obtaining fluid for appropriate diagnostic analysis

• 3.

  Assessment of pericardial and right heart hemodynamics before and after fluid drainage to assess for effusive-constrictive pericarditis.

Elective pericardiocentesis is contraindicated in patients receiving systemic anticoagulation, in patients with platelet or bleeding disorders, in patients with a platelet count of less than 50,000/µL, and in suspected hemorrhagic pericardial effusion from acute aortic dissection. Additionally, pericardiocentesis should be performed with caution in persons with organized or loculated pericardial effusions or significant pericardial adhesions from prior surgery. Consideration in these cases should be given to surgical pericardiotomy or pericardioscopic assisted pericardial access.

Pericardiocentesis Technique

Pericardiocentesis is most often performed within the catheterization laboratory under fluoroscopic and electrocardiographic guidance. However, the procedure can also be safely performed at the bedside under echocardiographic guidance and some operators prefer using both fluoroscopy and echocardiography.

The most common approach is subxiphoid, although apical and parasternal approaches are also feasible. The subxiphoid is the safest approach when echocardiographic guidance is not available.

The skin in the subxiphoid area is shaved and sterilized with a topical antiseptic solution. The patient is then draped with an aperture drape sheet. The patient is placed on continuous cardiac and blood pressure monitoring. Prophylactic broad spectrum antimicrobial antibiotics should be administered, using a single intravenous dose of a second or third generation cephalosporin antibiotic or vancomycin if the patient has a penicillin allergy or is colonized with methicillin-resistant Staphylococcus aureus .

An electrocardiography (ECG) electrode is attached to a large-bore needle at least 5 cm in length using an alligator clip. Most operators use either a Tuohy spinal needle or Pajunk needle for pericardial access. Pericardiocentesis utilizes the Seldinger technique of catheter insertion.

After administration of local anesthetic, the needle is slowly advanced toward the pericardial space. For the subxiphoid approach, the needle is inserted in the angle between the xiphoid process and the left costal margin and advanced at a 45 ° angle toward the left shoulder. For the apical approach, echocardiography is often used to identify the spot at which the pericardium is closest to the skin. Alternatively, the needle is inserted 1 cm outside the point of maximal impulse within the intercostal space and directed toward the right shoulder. For the parasternal approach, the needle is inserted immediately adjacent to the sternum, usually in the fifth intercostal space, with care being taken to avoid the vessels coursing along the inferior border of each rib.

Regardless of approach, the needle is slowly advanced with periodic attempts to gently aspirate fluid. While advancing the needle, special attention is given to the attached ECG electrode lead. Elevation of the ST or PR segment is seen when the needle is in direct contact with the myocardium. Atrial or ventricular ectopic beats can also be seen. If this occurs, slow withdrawal of the needle until ECG changes resolve should position the needle tip within the pericardial space.

A discrete pop is often felt upon entering the pericardial space. Once the pericardial space is entered, contrast or agitated saline injection can confirm needle position using either fluoroscopy or echocardiography, respectively ( Figure 35-1 and Video 35-1 ). This is especially recommended if hemorrhagic fluid is obtained. Alternatively, the aspirate can be injected into a cup. Pericardial fluid, even when hemorrhagic, will not clot, whereas intracardiac blood will.

A stiff guidewire is introduced into the pericardial space through the needle. A dilator is used to dilate the soft tissue tract and a pigtail pericardial drainage catheter is then inserted over the stiff guidewire ( Figure 35-2 ). In the catheterization laboratory, the intrapericardial pressures should then be documented by transducing the pericardial catheter. Additionally, radiographic contrast material can be injected through the catheter to confirm position and freedom within the pericardial space.

The pericardial fluid is then drained. Table 35-2 outlines the basic biochemical, microbiologic, and pathologic analyses pericardial fluid should be tested for. Once complete, pericardial pressures are often reassessed to document the degree of improvement. The pericardial catheter is often left in place to allow for continuous drainage or as a route to allow percutaneous pericardial window creation and/or instillation of sclerosing or chemotherapeutic agents. In this situation, the catheter is sutured in place and a sterile dressing applied.

Echocardiographic-guided pericardiocentesis is a safe and effective alternative to conventional EKG and fluoroscopic guidance. In a case series of 1127 therapeutic echo-guided pericardiocentesis procedures performed in 977 patients at the Mayo Clinic from 1979 to 1998, the procedural success rate was 97%, with an overall complication rate of 4.7%. Echocardiography guidance is particularly useful in organized loculated effusions and often utilizes a left anterior chest wall approach rather than the conventional subxiphoid approach.

PostPericardiocentesis Catheter Management

Pericardiocentesis may not completely remove the effusion in most cases, and therefore it is not unusual for the drainage catheter to be kept in place for 24 hours to 72 hours following the procedure.

Attempts to drain the pericardium should continue until <50 cc of fluid is drained within a 24-hour period. However, the catheter should be removed as soon as possible in order to minimize the risk of infection within the pericardial space.

The patient is usually maintained on continuous cardiac monitoring and the volume and rate of catheter drainage are recorded. The pericardial catheter can be drained by gravity continuously or alternatively drained manually using sterile technique every 4 to 8 hours. Heparinized saline (2 to 3 cc) should be instilled into the catheter after each drainage attempt. Follow-up echocardiography can be useful to determine resolution of the collection. Intravenous antibiotics are given while the drain remains in place for prophylaxis against pericardial infection. It is our institutional practice to administer cefotaxime 1 gram every 8 hours or vancomycin 500 to 1000 mg every 12 hours if the patient has a penicillin allergy or methicillin-resistant Staphylococcus aureus colonization.

Patients who continue to drain more than 75 to 100 mL daily 3 days after catheter placement or who reaccumulate with recurrence of tamponade should be considered for additional therapeutic strategies including intrapericardial sclerosing or chemotherapy agents, radiotherapy, percutaneous balloon pericardial window (as outlined below), and surgical pericardial window.