Chapter 11 Pericardial Disorders and Cardiac Tumors
Incidence and Signalment
Chief Complaints and History
Physical Examination Findings
Figure 11-1 Thoracic radiographs from a dog with pericardial effusion. A, The lateral projection shows a markedly enlarged cardiac silhouette, tracheal elevation, and overlap of the cardiac silhouette and diaphragm. B, The ventrodorsal projection shows bilateral contact between the pericardial sac and the costal margins. The edge of the cardiac silhouette is sharply delineated, and the lung fields are clear of any infiltrate that would indicate the presence of left-sided congestive heart failure.
Figure 11-2 Electrocardiograms (lead II) from dogs with pericardial effusion. Calibration square wave is 1mV in amplitude. A, Before pericardiocentesis, the complexes are low voltage (R wave < 1 mV) and heart rate is 140 beats per minute (bpm). B, After pericardiocentesis, R wave amplitude is almost 2 mV and heart rate is 100 bpm. C, Beat-to-beat variations in amplitude and contour of the QRS and ST-T complexes that characterize electrical alternans.
(Modified from Tobias AH: Pericardial disorders. In Ettinger SJ, Feldman EC, eds: Textbook of veterinary internal medicine, ed 6, St Louis, 2005, WB Saunders.)
Pericardial Fluid Analysis
Figure 11-3 Echocardiographic tamponade in a dog with pericardial effusion (PE). The images were recorded from the right parasternal location. A, Late diastolic inversion of the right atrium (arrow). The mass at the atrioventricular groove was confirmed as hemangiosarcoma by surgical biopsy. B, Diastolic inversion of the right ventricular wall (arrow). RV, Right ventricle.
Figure 11-4 Echocardiographic images from a dog with cardiac hemangiosarcoma recorded in the short-axis view from the right parasternal location. A, A cavitary and cystic mass (arrow) is associated with the right auricle (RA). B and C, The mass moves back and forth with right auricular motion during different phases of the cardiac cycle. AO, Aorta; PE, pericardial effusion.
Figure 11-5 Echocardiographic images from a dog with a heart base tumor recorded from the left cranial parasternal location. A, A large homogeneous mass (arrow) is attached to the caudal aspect of the aorta (AO). B, The tumor has infiltrated the main pulmonary artery (PA). LVOT, Left ventricular outflow tract; LA, left atrium.
Initial Patient Stabilization: Pericardiocentesis
The presence of pericardial fluid greatly facilitates the detection of intrapericardial masses, and this is particularly relevant to the diagnosis and delineation of hemangiosarcoma and heart base tumors. Pericardial fluid forms an echolucent zone around the right atrium and auricle and the ascending aorta, the locations at which these tumors most commonly occur. In the absence of pericardial fluid, these locations are obscured by lung interference. Consequently, whenever the clinical condition of the patient permits, pericardiocentesis should be deferred until a thorough echocardiographic examination has been completed.