Thoracoscopic partial pericardiectomy in 13 dogs

Thirteen dogs with cardiac tamponade resulting from pericardial effusion were prospectively evaluated to determine feasibility and outcome of thoracoscopic partial pericardiectomy. A lateral thoracoscopic approach allowed adequate exposure to remove a 4- to 5-cm-diameter section of pericardium in all dogs. Complete resolution of cardiac tamponade occurred in all dogs for which there was follow-up (11 dogs). Ten of 13 dogs (76.9%) had neoplastic pericardial effusion. One of these dogs remains alive at 220 days postoperatively and is asymptomatic. The mean survival of the remaining 9 patents with neoplastic effusion was 128 days (range, 14-544 days; median, 38 days). Three of 13 patients (23.1%) had idiopathic pericardial effusion. Two of these dogs remain alive at 585 and 1,250 days postoperatively. One dog with idiopathic pericardial effusion developed cardiomyopathy and was euthanized 18 days after the procedure. Results indicate that the procedure was technically successful in all dogs. No anesthetic complications occurred. Procedural complications included phrenic nerve transection (1 dog), lung laceration (1 dog), and moderate intraoperative bleeding (1 dog). No adverse clinical manifestations of the complications were apparent. We conclude that thoracoscopic partial pericardiectomy is technically feasible and offers several advantages over conventional open thoracic surgical pericardiectomy.     

Evaluation of the presence of selected viral and bacterial nucleic acids in pericardial samples from dogs with or without idiopathic pericardial effusion

Many viruses have been identified in pericardial fluid and in tissue samples from humans with pericarditis by means of molecular diagnostics. In canine idiopathic pericardial effusion there is as yet no conclusive evidence to support the involvement of an infectious agent. This study was designed to investigate a possible relationship between idiopathic pericardial effusion in dogs and viruses most commonly encountered in humans affected with viral pericarditis. Coxsackievirus B3 RNA, influenza virus type A RNA, human adenovirus type 2 DNA, human cytomegalovirus DNA, and parvovirus B19 DNA were investigated using PCR on pericardial effusion samples and pericardial tissue specimens collected from 14 dogs with idiopathic pericardial effusion. PCR was also used to test for two bacteria, Borrelia burgdorferi and Chlamydia pneumoniae. The same microorganisms were also looked for in pericardial effusions or pericardial washes from 10 dogs with neoplastic pericardial effusion, and in samples collected from 10 dogs which died of a non-cardiac disease. One pericardial effusion sample from a dog with the idiopathic form of the disease tested positive for influenza virus type A and sequencing of the amplicon confirmed the PCR result. In another dog from the same group a cytomegalovirus was detected by PCR in the effusion, but sequencing showed this to be a false-positive result. The genomes of the microorganisms investigated were not detected in neoplastic effusions or pericardial washes. The results indicate that viral and bacterial DNA/RNA of relevance for human pericarditis is rare in pericardial samples from dogs with idiopathic pericardial effusion. The finding of influenza type A viral RNA in pericardial fluid from one dog with the idiopathic form of the disease warrants further investigation.     

Canine pleural and mediastinal effusions: a retrospective study of 81 cases

Eighty-one cases of canine pleural and/or mediastinal effusions were identified from radiography and ultrasonography records reviewed between 1992 and 2000 at the Queen's Veterinary School Hospital, University of Cambridge. All cases had a follow-up period of at least 12 months. Twenty-eight underlying disease processes were associated with pleural and/or mediastinal effusions. The most common disease was pyothorax (13 cases). Other common diseases identified were idiopathic pericardial effusion, cranial mediastinal mass, idiopathic chylothorax, secondary lung metastases and dilated cardiomyopathy. Approximately one-quarter of all cases recovered completely after initial treatment and one-third of all cases either died during, or were euthanased immediately after, completion of the initial investigations.     

Analysis of Factors Affecting Survival in Dogs With Aortic Body Tumors

OBJECTIVE: To evaluate the effect of perioperative and operative variables on survival time in dogs with aortic body tumors. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Twenty-four client-owned dogs with histologically confirmed aortic body tumor. METHODS: Seventy-eight patient records of dogs seen at the University of Illinois Veterinary Teaching Hospital between 1989 and 1999 with a diagnosis of a heart-base mass were reviewed. Dogs without histologic conformation of an aortic body tumor were excluded. Age; sex; breed; the presence of pleural effusion, pericardial effusion, or abdominal effusion; evidence of cardiac arrhythmias; evidence of distant metastasis; treatment with pericardectomy; treatment with chemotherapy; and time from diagnosis until euthanasia or death were recorded on a spreadsheet. Cox proportional-hazard ratios were used to calculate the relationship of risk variables to survival time. Median survival time was determined using life-table analysis. RESULTS: Twenty-four dogs met the criteria for inclusion in the study. The median age of dogs with aortic body tumors was 9 years. All dogs had a surgical biopsy performed. Fourteen dogs had a pericardectomy at the time of the biopsy procedure. Of all factors analyzed, only treatment with pericardectomy had a significant influence on survival (P =.0029). Dogs that had pericardectomy survived longer (median survival, 730 days; range, 1-1,621 days) compared with dogs that did not have pericardectomy (median survival, 42 days; range, 1-180 days). This finding was independent of the presence or absence of pericardial effusion at the time of surgery. CLINICAL RELEVANCE: Dogs that are diagnosed with aortic body tumors may benefit from a pericardectomy at the time of surgical biopsy.     

Idiopathic effusive pericarditis with tamponade in the horse

Pericarditis and pericardial effusion are considered to occur rarely in the horse. The clinical and laboratory features of idiopathic pericarditis with effusion diagnosed in 10 horses over a seven-year period were reviewed. Consistent physical findings included tachycardia, ventral oedema, jugular venous distention and diminished heart sounds. Electrocardiographic features included diminished voltages and electrical alternans, and the effusion was identified by echocardiography in the six horses in which it was performed. Pericardiocentesis relieved clinical signs in nine horses. Laboratory analysis of pericardial fluid samples classified six cases as aseptic serofibrinous, three cases as eosinophilic, and one case as histiocytic. One horse died and three were destroyed. The remaining six horses recovered following pericardiocentesis (performed once or twice) with or without corticosteroid treatment, and were alive one month to seven years after diagnosis.     

Cardiac lymphoma and pericardial effusion in dogs: 12 cases (1994-2004)

OBJECTIVE: To determine clinical characteristics and clinicopathologic findings, including results of pericardial fluid analysis, and determine the outcome associated with pericardial effusion caused by cardiac lymphoma in dogs. DESIGN: Retrospective case series. ANIMALS: 12 dogs. PROCEDURE: Medical records of affected dogs were reviewed for echocardiographic findings, radiographic findings, results of pericardial fluid analysis, clinicopathologic findings, treatment protocols, and outcomes. RESULTS: Pericardial effusion was detected by echocardiography in all 12 dogs, and lymphoma was detected by cytologic examination of the effusion (11/12 dogs) or histologic examination of pericardium (3/12). Large-breed dogs were overrepresented; median weight was 40.5 kg (89.1 lb). Most hematologic and biochemical changes were mild and non-specific. Survival time for dogs treated with combination chemotherapeutic agents was 157 days and for dogs that did not receive chemotherapy survival time was 22 days. This difference was not significant, but several dogs had long-term survival. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac lymphoma is an uncommon cause of pericardial effusion, and results suggest that cardiac lymphoma does not always warrant the poor prognosis of other stage V, substage b lymphomas.     

DIAGNOSTIC PNEUMOPERICARDIOGRAPHY IN DOGS WITH SPONTANEOUS PERICARDIAL EFFUSION

To evaluate the diagnostic accuracy of pneumopericardiography, diagnostic pneumopericardiograms from 39 dogs with spontaneous pericardial effusion of various etiologies were reviewed. Diagnoses were confirmed by surgical biopsy, necropsy, or follow-up evaluation. Thirty-two of 39 studies (82%) were considered diagnostic. There were one false-positive and six false-negative studies. Fifteen of 16 studies (94%) in dogs with idiopathic sanguinous pericardial effusion were negative (i.e., similar to those in normal dogs). Seven of 12 right atrial hemangiosarcomas (58%), six of six heartbase neoplasms (100%), and two of two pericardial cysts (100%) were outlined. Studies in two cases of infective pericarditis revealed abnormal findings, while a negative study was obtained in one patient with pericardial mesothelioma. Lateral positions were most valuable in idiopathic effusions and for outlining heartbase neoplasms. The left lateral recumbent position was particularly important for outlining hemangiosarcomas. Pericardial cysts were profiled best in ventral or dorsal recumbent positions. This study documents the high diagnostic potential of technically adequate pneumopericardiograms in the etiologic diagnosis of pericardial effusion in the dog.     

Vascular endothelial growth factor concentrations in body cavity effusions in dogs

Vascular endothelial growth factor (VEGF) has potent angiogenic, mitogenic, and vascular permeability enhancing properties specific for endothelial cells. VEGF is present in high concentrations in inflammatory and neoplastic body cavity effusions and has been implicated in the pathogenesis of neoplastic and inflammatory effusion formation. In this study, VEGF was quantitated by solid-phase enzyme-linked immunoadsorbent assay (ELISA) in samples of pericardial, pleural, and peritoneal effusions (N = 38) from dogs (N = 35) with neoplastic and non-neoplastic diseases. VEGF was detected in 37 of 38 effusions (median, 754; range, 18-3,669 pg/mL) and was present in much higher concentrations than in previously established normal concentrations for canine plasma (median, < 1 pg/mL; range, < 1-18 pg/mL) or in those previously noted in the plasma of dogs with hemangiosarcoma (HSA; median, 17 pg/mL; range, < 1-67 pg/mL). In 4 dogs with HSA, the concurrent plasma VEGF concentration was much lower than in the abdominal effusion (P = .029). No significant correlation was demonstrated between VEGF effusion concentration and effusion total protein content or nucleated cell count. Mean VEGF concentrations were significantly higher in pericardial (median, 3,533; range, 709-3,669 pg/mL) and pleural effusions (median, 3,144; range, 0-3,663 pg/mL) compared to peritoneal effusions (median, 288; range, 18-2,607 pg/mL; P < .05). There was no marked difference demonstrated between effusions associated with malignant and nonmalignant diseases. Further studies are necessary to elucidate the role of VEGF in body cavity effusion formation in dogs.     

Diagnostic Yield of Cytologic Analysis of Pericardial Effusion in Dogs

Background

Pericardial effusion cytology is believed by many to be of limited value, yet few studies have evaluated its diagnostic utility.

Objectives

To determine the diagnostic utility of cytologic analysis of pericardial effusion in dogs and to determine if consideration of additional data could improve the diagnostic yield.

Animals

Two hundred and fifty‐nine dogs with cytologic analysis of pericardial effusion performed between April 1990 and June 2012.

Methods

Electronic medical records from a university teaching hospital were retrospectively reviewed; signalment, complete blood count, serum biochemistry, cytologic analysis of pericardial effusion, and echocardiographic data were recorded. Cytology was classified as diagnostic (infectious or neoplastic) or nondiagnostic (hemorrhagic or other) and groups were compared with multiple Student''s t‐tests.

Results

Cytology was grouped as nondiagnostic (92.3%) or diagnostic (7.7%) and characterized as hemorrhagic (90%), neoplastic (4.6%), infectious (3.1%), or other (2.3%). Overall cytologic analysis of pericardial effusion diagnostic utility was 7.7% and increased to 20.3% if the effusion hematocrit (HCT) <10%; echocardiographic evidence of a mass did not result in a significant increase in the diagnostic utility.

Conclusions and Clinical Importance

The diagnostic utility of cytologic analysis of canine pericardial effusion is variable depending on the underlying etiology. In this group of dogs, the diagnostic yield of cytologic analysis was greater for pericardial effusion samples in which the HCT was less than 10%.     

Biochemical analysis of pericardial fluid and whole blood in dogs with pericardial effusion

Studies evaluating pericardial fluid analysis in dogs to determine the etiology of pericardial effusions have yielded conflicting results. The purpose of this prospective study was to compare acid-base status, electrolyte concentrations, glucose, and lactate of pericardial fluid to peripheral blood from dogs with pericardial effusion and to compare these variables between dogs with neoplastic and nonneoplastic pericardial effusion. Acid-base status, electrolyte concentrations, glucose, hematocrit, urea nitrogen, and lactate concentrations were evaluated in peripheral blood samples and in pericardial effusion samples of 41 client-owned dogs with pericardial effusion. Common abnormal findings in the peripheral blood of dogs with pericardial effusion included hyperlactatemia (n = 38 [of 41]; 93%), hyponatremia (n = 25/41; 61%), hyperglycemia (n = 13/41; 32%), and hypermagnesemia (n = 13/41; 32%). Bicarbonate, sodium, ionized calcium, glucose, and hematocrit were all significantly lower in the pericardial fluid compared with peripheral blood, whereas lactate, chloride, and PCO2 were significantly higher in the pericardial fluid. When comparing the concentrations of variables in the pericardial fluid of dogs with neoplasia (n = 28) to those without neoplasia (n = 13), pH, bicarbonate, and chloride were significantly lower in dogs with neoplasia, whereas lactate, hematocrit, and urea nitrogen were significantly higher in the pericardial fluid of dogs with neoplasia. The difference between peripheral and pericardial glucose concentrations was significantly larger in dogs with neoplasia than in dogs without neoplasia. Although differences between variables in dogs with neoplastic and nonneoplastic pericardial effusion were documented, clinical relevance is likely limited by the degree of overlap between the 2 groups.     

Left atrial rupture in dogs: 14 cases (1990–2005)

Objective: To describe the clinical parameters, treatment, and prognosis of dogs with left atrial rupture secondary to chronic mitral valve insufficiency. Design: Retrospective study. Setting: University referral hospital. Animals: 14 dogs with left atrial rupture. Interventions: None. Measurements and main results: Mixed breed dogs (n=6, 43%) and Shetland Sheepdogs (n=3, 21%) were most commonly affected. The median age was 12 years (range 5.8–18 y). The median weight was 11 kg (range 4–30 kg). Eight dogs had been previously diagnosed with chronic valvular disease. The most common presenting complaints included collapse (13/14), cough (9/14), and dyspnea (8/14). Four dogs were presented in either respiratory or cardiac arrest. Pericardial effusion was present in 13 dogs. The median left atrium:aortic outflow ratio was 2.66 (range 1.66:1–5.52:1). Pericardiocentesis was performed to alleviate tamponade in 3 dogs. Five dogs were discharged from the hospital, 3 of which were euthanized within 35 days of initial diagnosis for recurrence of clinical signs (n=2) and for hematochezia and lethargy (n=1). Five dogs were euthanized while in the hospital for a variety of reasons including DIC, progressive azotemia, collapse and recurrence of pericardial effusion, or possible seizure episode. Conclusions: Although rare, left atrial rupture resulting in pericardial effusion should be considered in older small‐ to medium‐sized dogs presenting with collapse, cough, and dyspnea. The overall prognosis appears poor.     

Pericardial mesothelioma in a Bengal tiger (Panthera tigris).

A 17-year-old Bengal tiger (Panthera tigris) presented with dyspnea and tachypnea. Radiographs revealed severe pleural and pericardial effusion, but no obvious mass. During attempts to remove the fluid under anesthesia, the cat developed cardiac tamponade and died. At necropsy, a nodular mass was found at the heart base and was identified as a pericardial mesothelioma. This is the first report of this tumor in any large cat.     

Long-term survival of 23 dogs with pericardial effusions

Twenty-three dogs with pericardial effusions were identified from case records made between 1992 and 2000. Fourteen of the 23 were diagnosed with idiopathic pericardial effusions, and three of these were treated successfully by one pericardiocentesis. In the remaining 11 cases the pericardial effusion recurred; six cases were managed long-term by either two (three cases), three (two cases), or 11 repeated pericardiocenteses, and the remaining five were treated by pericardiectomy. The median survival time of the six dogs treated by repeated pericardiocentesis was five years and nine days.     

A retrospective study of clinical findings, treatment and outcome in 143 dogs with pericardial effusion

A retrospective study of 143 dogs with pericardial effusion is presented, including a statistical analysis of survival time. Cases were classified into those in which a mass was seen on echocardiography (echo-positive) and those in which no mass could be identified (echo-negative). Forty-four dogs were echo-positive and 99 were echo-negative. The median survival time (MST) was 1068 days for echo-negative dogs and 26 days for echo-positive dogs. Dogs with a history of collapse were more likely to present with a mass on echocardiography. Those presenting with collapse had an MST of 30 days compared with 605 days for those without collapse. Echo-negative dogs tended to present with ascites and generally had a larger volume of pericardial effusion. The median survival for dogs presenting with ascites was 605 days compared with 45 days for those without ascites. Among echo-negative dogs, 64 per cent had a relapse of their effusion. Subtotal pericardiectomy was performed in 31 echo-negative dogs. The procedure had a perioperative mortality of 13 per cent but provided a favourable long-term prognosis. Dogs undergoing pericardiectomy had a median survival of 1218 days compared with 532 days for those not undergoing surgery.     

Percutaneous balloon pericardiotomy as a treatment for recurrent pericardial effusion in 6 dogs

Percutaneous balloon pericardiotomy (PBP) has been performed in people and in a small number of dogs as a treatment for recurrent pericardial effusion with tamponade (PET). We performed this technique on 6 dogs with recurrent PET (5 with heart base tumors and 1 with no identifiable mass). Under general anesthesia and fluoroscopic guidance, a balloon-dilating catheter (diameters 14-20 mm) was introduced percutaneously at the 5th intercostal space through a sheath-introducing catheter, positioned across the parietal pericardium, and inflated 3 times. No dog experienced serious complications. The procedure was considered successful in 4 of 6 dogs. One dog is still alive without recurrence of PET 1 year after the procedure. Three dogs died of unrelated disease without recurrence of PET 5. 19, and 32 months after the procedure. The procedure was not beneficial in 1 dog that was euthanized 9 weeks later because of recurrence of pleural and abdominal effusion thought to be secondary to PET. One dog may have temporarily benefited but developed symptomatic PET 6 months after PBP. PBP appears to be a safe, economical, and potentially effective palliative treatment for recurrent PET and is a reasonable, less invasive alternative to surgery for dogs with recurrent PET, especially effusions caused by heart base tumors and possibly idiopathic pericardial effusion. Premature closure of the stoma is a potential cause for long-term failure and was thought to have been responsible for the recurrence of clinical signs in 2 dogs.     

Adverse events associated with pericardiocentesis in dogs: 85 cases (1999–2006)

Objective – To quantify the frequency of adverse events occurring during or post pericardiocentesis and to determine if adverse events are related to the cause of the pericardial effusion or frequency of pericardiocentesis.
Design – Retrospective study.
Setting – Referral hospital.
Animals, Intervention and Measurements – Medical records of 85 dogs that underwent 112 episodes of pericardiocentesis were reviewed. Any adverse events during pericardiocentesis and in the 48 hours post pericardiocentesis were noted. The frequency of adverse events was compared between dogs with a suspected neoplastic cause and a suspected nonneoplastic cause of their pericardial effusion and also between the first and subsequent pericardiocenteses.
Main Results – The incidence of adverse events was 10.7% within 1 hour of pericardiocentesis and 15.2% within 48 hours. There was no significant difference in the frequency of adverse events between the groups. Most adverse events identified were dysrhythmias. Forty-one percent of those dogs with adverse events were euthanized or died within 48 hours.
Conclusion – The incidence of adverse events seen within 48 hours of pericardiocentesis was 15.2%.     

Electrocardiographic changes and cardiac pathology in canine babesiosis

The main purpose of this study was to describe electrocardiographic (ECG) changes in canine babesiosis, and to relate these to clinical severity, outcome and cardiac pathology.Four groups of dogs with babesiosis were studied: mild to moderate anemia, severe anemia, concurrent autoagglutination and concurrent complications. Lead II ECG was recorded at admission for 1 minute in all dogs (121). A six lead ECG was recorded in 88 dogs. Full necropsy was performed on 16 dogs (5 died on arrival, 11 had ECG recording).The following ECG changes were recorded in relatively high prevalence: sinoatrial blocks or sinus arrest (7%), ventricular premature complexes (7%), low R-amplitude (23%), prominent Q (13%), axis deviations (40%), prolonged QRS (32%), ST depression and coving (28%), large T (42%), and notched R (28%). Differences between groups were minor. There was a significantly higher prevalence of sinus bradycardia and irregular rhythm in the non-survivors. Gross pathological changes were pericardial effusion and hemorrhages. Histological changes were hemorrhages, necrosis, inflammation and fibrin microthrombi. The only correlation between pathology and ECG was low R-amplitude and pericardial effusion.The ECG changes were similar to the pattern described for myocarditis and myocardial ischemia, and together with the histopathological findings indicated that the heart suffers from the same pathological processes described in other organs in canine babesiosis, namely inflammation and hypoxia. As the clinical application of the ECG changes found in this study was limited, cardiovascular assessment should be based on functional monitoring rather than ECG.     

Pericardial effusion and cardiac tamponade in a cat with extranodal lymphoma

A five-year-old domestic longhaired cat was evaluated for a seven-day history of worsening respiratory distress. Serum analysis for feline leukaemia virus antigen was positive. Pleural effusion was detected on thoracic radiographs and echocardiography revealed a pericardial effusion and cardiac tamponade. Cytological evaluation of the pleural and pericardial effusions showed lymphoblastic cells indicative of disseminated lymphoma. Following thoracocentesis and pericardiocentesis, the cat was treated for lymphoma using the University of Wisconsin-Madison chemotherapy protocol. The cat was sent home after three days and, at the time of writing (six months after initial presentation), was still symptom free. To the authors' knowledge, this is the first report confirming pericardial effusion and cardiac tamponade in the cat as a direct result of an extranodal lymphoma with cytological evidence of neoplastic cells in the pericardial fluid.     

The prevalence of cardiomyopathy in the Irish wolfhound: a clinical study of 500 dogs

The prevalence of cardiomyopathy in Irish wolfhounds was evaluated by retrospective review of the results of cardiovascular examinations carried out in 500 dogs presented for veterinary services at the author's practice. Abnormalities were found in 209 (41.8%) of the dogs examined. Dilated cardiomyopathy (DCM) was diagnosed in 121 (24.2%) of the dogs and was accompanied by atrial fibrillation in 106 dogs. Seventeen dogs were suffering from advanced congestive heart failure (CHF), and 55 dogs were suffering from mild to moderate CHF as a result of DCM. Congestive heart failure was most commonly characterized by mild to severe pleural effusion due to right-sided heart failure in addition to pulmonary edema. Rhythm disturbances without evidence of DCM were detected in 48 dogs. Forty dogs had echocardiographic abnormalities without signs of DCM. Soft to moderate mitral regurgitations were diagnosed in 13 (2.6%) of these 40 dogs examined. In 39 dogs that died as a result of DCM, the median survival time from the time of diagnosis was 5.1 months, and in 59 dogs with DCM that are still alive, the median survival time is 15.7 months.     

Cardiac troponins I and T in dogs with pericardial effusion

Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) are sensitive and specific markers for myocardial ischemia and necrosis. Dogs with pericardial effusion frequently have myocardial ischemia and necrosis, and these changes are more severe in dogs with hemangiosarcoma (HSA). We investigated the utility of using serum cTnI and cTnT concentrations to identify the idiopathic pericardial effusion from that associated with HSA. Blood samples for measurement of cTnI and cTnT concentrations were collected before pericardiocentesis in 37 dogs with pericardial effusion. Eighteen dogs had a mass consistent with HSA, 6 dogs had idiopathic pericardial effusion, 1 dog had mesothelioma, and 1 dog had a heart base tumor. No final diagnosis was achieved for 11 dogs. Dogs with pericardial effusion had significantly higher serum concentrations of cTnI (P < .001) but not cTnT (P = .16) than did normal dogs. Dogs with HSA had significantly higher concentrations of cTnI (2.77 ng/dL; range: 0.09-47.18 ng/dL) than did dogs with idiopathic pericardial effusion (0.05 ng/dL; range: 0.03-0.09 ng/dL) (P < .001). There was no difference in the concentration of cTnT between dogs with HSA and those with idiopathic pericardial effusion (P = .08). Measurement of cTnI may be useful in helping to distinguish between idiopathic pericardial effusion and pericardial effusion caused by HSA.