In cases of malignant pericardial tamponade, symptoms are nearly ubiquitous. Patient complaints are often dramatic and include syncope, chest pain, or palpitations; more subtle symptoms include dyspnea, chest heaviness, and simple fatigue. Components of the often-described clinical triad of hypotension, tachycardia, and muffled heart tones are usually present. These physical findings, along with distended neck veins and a pulsus paradoxus, lead to a diagnosis of tamponade. Impaired venous return from elevated pericardial pressure leads to inadequate right heart filling and decreased stroke volume. In an effort to maintain cardiac output, the host manifests a chronotropic response until preload becomes limiting. Without intervention at this advanced stage, patients may show all the hallmarks of a low-output shock state, including cold, clammy skin, oliguria, and altered mental status. The severity of these signs and symptoms and the history of a prior malignancy will dictate the urgency for diagnostic and therapeutic intervention. www.mycanadianpharmacy.com
Chest radiographs provide nonspecific supporting evidence for pericardial effusions. Frontal views show widening of the cardiac silhouette. In one third of cases, a coexistent pleural effusion is seen. Transthoracic echocardiography is universally used to evaluate the anatomy noninvasively, as well as the physiologic consequences of pericardial fluid accumulation. By using parasternal, sub-xiphoid, and transesophageal echocardiographic views, the entire pericardial space can be examined sonographically. The quality of the fluid (homogeneous vs heterogeneous), presence of bulky tumor, presence of loculations, and the precise location of the fluid can be determined. In addition, determinations of right and left ventricular function and the presence or absence of right ventricular and atrial diastolic collapse are sought. Despite strong supporting images from transthoracic echocardiography and transesophageal echocardiography, right heart catheterization remains the definitive and quantifiable standard for diagnosing tamponade of any etiology. Equalization of diastolic pressures across all cardiac chambers is the hallmark of tamponade. Patients found to exhibit this finding should undergo immediate catheter drainage under echocardio-graphic or fluoroscopic guidance. Opening pericardial pressures usually equilibrate cardiac diastolic pressures. With effective drainage, the pericardial and intracardiac diastolic pressures fall with a concomitant improvement in forward cardiac output. As with pleural samples, pericardial fluids are routinely sent for chemical, microbiological, and cytologic studies. Only cytologic study can diagnose malignancy, with other biochemical assays or cultures supporting this or alternative etiologies.