Treatment of three cats with hyperviscosity syndrome and congestive heart failure using plasmapheresis

Three cats were evaluated at a veterinary teaching hospital for congestive heart failure (CHF) secondary to hyperviscosity syndrome from plasma cell neoplasia. All cats had severe hyperproteinemia due to hyperglobulinemia. Multiple myeloma or plasma cell neoplasia was diagnosed based on cytopathology and post mortem examination. The cats presented with signs of CHF including acute collapse, tachypnea, increased respiratory effort, and pulmonary crackles. All cats had heart murmurs and echocardiographic signs consistent with hypertrophic cardiomyopathy. An enlarged left atrium was found in all cats and two of three cats also had spontaneous echocardiographic contrast. Plasmapheresis (centrifugal plasma exchange) was performed on all three cats by the removal of whole blood and the infusion of a balanced electrolyte solution while the whole blood was centrifuged and separated. The RBCs were then washed before being readministered to the patient. Plasmapheresis alleviated the clinical signs of CHF (tachypnea) in all three cats. Plasmapheresis should be considered in cases of CHF secondary to hyperviscosity syndrome to rapidly alleviate clinical signs associated with heart failure while diagnosis of the underlying cause is made and appropriate therapy implemented.     

Hypertropic cardiomyopathy and hyperthyroidism in the cat

In a 21/2-year period, hypertrophic cardiomyopathy was found at necropsy of 23 cats that died (13 cats) or were euthanatized (10) because of problems associated with hyperthyroidism. Of these, 4 (17%) also had evidence of cardiac failure (pulmonary edema or pleural effusion). The mean body weight of the cats with hyperthyroidism and hypertrophic cardiomyopathy was significantly less (P less than 0.001) than that of clinically normal cats and cats with primary cardiomyopathy (congestive or restrictive) or excessive moderator band cardiomyopathy. In addition, the ratio of heart weight to body weight was significantly greater (P less than 0.001) in the 23 hyperthyroid cats than in the normal cats and cats with primary cardiomyopathy. Twenty (87%) of the cats had symmetric hypertrophy of the ventricular septum and left ventricular free wall, whereas the remaining 3 cats had disproportionate thickening of the ventricular septum, compared with the free wall, similar to what is found in cats with asymmetric hypertrophic cardiomyopathy. Histologic cardiac abnormalities included large, hyperchromatic nuclei, interstitial fibrosis, endocardial fibroplasia, fibrosis of the atrioventricular node, and marked disorganization of cardiac muscle cells. The study showed that hypertrophic cardiomyopathy develops in most hyperthyroid cats, some of which also develop congestive heart failure. Although the signs of heart disease in primary myocardial disease and thyrotoxic disease are similar, the characteristic signalment and clinical signs of hyperthyroidism should lead one to suspect the association of hypertrophic cardiomyopathy with the hyperthyroidism.     

Canine hypertrophic cardiomyopathy.

Necropsy findings in 10 dogs with naturally occurring cardiac disease closely resembled hypertrophic cardiomyopathy in human beings and cats. Each dog had marked cardiac hypertrophy, and 8 dogs had disproportionate thickening of the ventricular septum with respect to the left ventricular free wall (compared with dogs with normal hearts or with cardiac hypertrophy due to acquired or congenital heart disease). Ratios of septum to free wall thickness in the 10 dogs ranged from 1.1 to 1.5, and 6 had ratios greater than or equal to 1.3. Marked cardiac muscle cell disorganization in the ventricular septum, characteristic of human patients with hypertrophic cardiomyopathy, was found in only 2 of the 10 dogs. Death occurred while the dogs were under anesthesia during the course of operative procedures (5 dogs) or unexpectedly in animals without previous manifestations of cardiac disease (3 dogs). Four dogs had clinical signs of congestive heart failure, including 2 with marked cardiac decompensation. Two of these 4 dogs with heart failure and 1 dog that died during unrelated surgery, but without prior signs of heart disease, had electrocardiographic evidence of complete heart block.     

Retrospective Evaluation of the Effect of Heart Rate on Survival in Dogs with Atrial Fibrillation

Background

Atrial fibrillation (AF) usually is associated with a rapid ventricular rate. The optimal heart rate (HR) during AF is unknown.

Hypothesis/Objectives

Heart rate affects survival in dogs with chronic AF.

Animals

Forty‐six dogs with AF and 24‐hour ambulatory recordings were evaluated.

Methods

Retrospective study. Holter‐derived HR variables were analyzed as follows: mean HR (meanHR, 24‐hour average), minimum HR (minHR, 1‐minute average), maximum HR (maxHR, 1‐minute average). Survival times were recorded from the time of presumed adequate rate control. The primary endpoint was all‐cause mortality. Cox proportional hazards analysis identified variables independently associated with survival; Kaplan‐Meier survival analysis estimated the median survival time of dogs with meanHR <125 bpm versus ≥125 bpm.

Results

All 46 dogs had structural heart disease; 31 of 46 had congestive heart failure (CHF), 44 of 46 received antiarrhythmic drugs. Of 15 dogs with cardiac death, 14 had CHF. Median time to all‐cause death was 524 days (Interquartile range (IQR), 76–1,037 days). MeanHR was 125 bpm (range, 62–203 bpm), minHR was 82 bpm (range, 37–163 bpm), maxHR was 217 bpm (range, 126–307 bpm). These were significantly correlated with all‐cause and cardiac‐related mortality. For every 10 bpm increase in meanHR, the risk of all‐cause mortality increased by 35% (hazard ratio, 1.35; 95% CI, 1.17–1.55; P < 0.001). Median survival time of dogs with meanHR<125 bpm (n = 23) was significantly longer (1,037 days; range, 524‐open) than meanHR ≥125 bpm (n = 23; 105 days; range, 67–267 days; P = 0.0012). Mean HR was independently associated with all‐cause and cardiovascular mortality (P < 0.003).

Conclusions and Clinical Importance

Holter‐derived meanHR affects survival in dogs with AF. Dogs with meanHR <125 bpm lived longer than those with meanHR ≥ 125 bpm.     

Clinical usefulness of cardiac event recording in dogs and cats examined because of syncope, episodic collapse, or intermittent weakness: 60 cases (1997-1999)

OBJECTIVE: To determine the clinical usefulness of cardiac event recording in evaluating dogs and cats with unexplained syncope, episodic collapse, or intermittent weakness. DESIGN: Retrospective study. ANIMALS: 58 dogs and 2 cats. PROCEDURE: Medical records and electrocardiographic rhythm strips obtained by cardiac event recordings were reviewed. Cardiac rhythm data from the event recordings were classified as diagnostic or nondiagnostic. Diagnostic yield was calculated by dividing the number of animals for which cardiac event recording was diagnostic by the total number of animals undergoing cardiac event recording. RESULTS: For 51 animals, cardiac event recording was classified as diagnostic; therefore, overall diagnostic yield was 85%. Diagnostic yield was lower for animals without underlying structural heart disease (75.5%) than for animals with structural heart disease (95.6%). A specific arrhythmia was identified as the cause of clinical signs in 18 of the 51 (35%) animals for which cardiac event recording was diagnostic. Cardiac arrhythmia was definitively excluded as the cause of clinical signs in the remaining 33 (65%) animals in which cardiac event recording was diagnostic. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that cardiac event recording had a high diagnostic yield in dogs and cats examined because of unexplained syncope, episodic collapse, or transient weakness and ataxia, regardless of whether animals did or did not have an underlying structural heart disease. Diagnostic yield of cardiac event recording was higher than that reported previously for Holter monitoring.     

Pericardial effusion in cats: a retrospective study of clinical findings and outcome in 146 cats

BACKGROUND: Pericardial effusion (PE) in dogs most often is associated with neoplasia or idiopathic pericarditis, and frequently causes cardiac tamponade. Studies of PE in the cat are limited. HYPOTHESIS: Congestive heart failure (CHF) is the most common cause of PE in the cat. ANIMALS: All cats diagnosed with PE on echocardiographic examination at the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania (MJR-VHUP) from 2000 to 2005. METHODS: The clinical and pathologic findings in 146 cats with PE were reviewed. Records were examined retrospectively to identify additional underlying conditions. Follow-up status and cause of death were determined by review of the medical records or phone interviews with the owners. RESULTS: The most common cause of PE in this study was CHF (75%). Biochemical abnormalities were uncommon, but aspartate aminotransferase (AST) activity frequently was increased (85%). Follow-up information was available on 108 cats (74%). Median survival time (MST) was 144 days for cats that were not euthanized within 24 hours (n = 85). The MST of cats with heart failure was 41 days, whereas the MST of cats without heart failure was 361 days, when those euthanized within 24 hours were excluded. CONCLUSIONS: Survival time of cats with heart failure in this study was significantly shorter than previously reported, and significantly shorter than in cats without heart failure as a cause of PE.     

Risk factors, clinical signs, and survival in cats with a clinical diagnosis of idiopathic hypertrophic cardiomyopathy: 74 cases (1985-1989).

Population characteristics, risk factors, and survival characteristics were evaluated in 74 cats with hypertrophic cardiomyopathy (HC) seen at North Carolina State University veterinary teaching hospital from 1985 to 1989, and compared with 82 clinically normal cats. The mean (+/- SD) age of cats with HC was 6.5 (4.0) years. Neutered males were at significantly greater risk (odds ratio 3.1) than neutered females. Breed, body weight, or coat color were not determined to be risk factors for HC. Tricolor cats were significantly underrepresented, probably reflecting the male predisposition for HC and not a true risk reduction associated with coat color. Forty-one cats were without clinical signs of heart disease (murmur and/or gallop sound only), 24 were in congestive heart failure, and 9 had systemic arterial embolism, 3 of which had concomitant congestive heart failure. The median survival time for 61 cats with HC, for which survival information could be obtained and that were not euthanatized on day 1, was 732 days. Survival was not affected by age at diagnosis, breed, body weight, or sex. However, clinical signs were important in determining prognosis; cats with heart rates greater than 200 beats/min survived significantly longer (median survival greater than 1,830 days) than those with heart rates greater than or equal to 200 beats/min (median survival = 152 days). Cats without clinical signs (median survival greater than 1,830 days) survived longer than those with clinical signs, and cats in heart failure survived a median of 92 days, compared with 61 days for those with systemic arterial embolism. Analysis of survival revealed no significant difference between the 2 groups of cats with clinical signs; however, all cats with embolism and only 60% of cats with heart failure were dead 6 months after diagnosis.     

Effect of cilobradine in cats with a first episode of congestive heart failure due to primary cardiomyopathy

IntroductionHeart rate (HR) is often elevated in cats with cardiomyopathies (CMPs). Pharmacologic modulation of HR may reduce cardiac morbidity and mortality.ObjectivesTo investigate the effects of cilobradine vs. placebo, regarding time to cardiac mortality or morbidity in cats with first episode of congestive heart failure (CHF) due to primary CMP.AnimalsThree hundred and sixty-seven client-owned cats with primary CMP that had presented with a first episode of CHF at 50 centers in Europe. Per-protocol population comprised 193 cats (n = 89 cilobradine, n = 104 placebo). An interim analysis for futility was planned.MethodsProspective, randomized, placebo-controlled, double-blinded, multicenter clinical trial. Primary outcome variable was the time to a composite of cardiac mortality or cardiac morbidity.ResultsMedian time to primary outcome was 84 days (95% confidence interval [CI]: 63–219 days) in the cilobradine group (CG) and 203 days in the placebo group (95% CI: 145–377 days) with observed hazard ratio of 1.44, indicating a higher hazard for the CG (P = 0.057). Mean HR was 28 beats per minute (bpm) lower at Day 7 (P < 0.0001) and remained 29 bpm lower at Day 360 (P = 0.026) in the CG than that in the placebo group. Although the number of adverse events did not differ, there were more serious adverse events in the CG.ConclusionsHeart rate reduction by cilobradine in cats with a first episode of CHF due to primary CMP did not reduce cardiac mortality and morbidity.     

Congestive heart failure associated with hyperthyroidism in cats

Hyperthyroidism was diagnosed in 4 cats with congestive heart failure. Dyspnea and anorexia were observed in 3 of the 4 cats. In each cat, a holosystolic left and/or right apical heart murmur was auscultated. In 3 cats, a prominent extra heart sound (gallop rhythm) was auscultated. All cats had a palpably large thyroid lobe(s) and weight loss. The laboratory and ECG changes were similar to those reported for feline hyperthyroidism. Moderate-to-severe pleural effusion and cardiomegaly were detected via radiography in all cats. Some cats had radiographic signs of pulmonary venous engorgement and pulmonary edema. Echocardiography revealed cardiac dilatation and low left ventricular shortening fraction (wall motion) in all cats. Three cats responded initially to cardiac drugs and propylthiouracil or thyroidectomy. One of these died later, presumably from an adverse reaction to propylthiouracil, and the others died from recurrent congestive heart failure (1) or postoperative cardiac arrest (1). One cat did not respond to treatment, and died 2 days after diagnosis.     

Assessment of plasma cardiac troponin I concentration as a means to differentiate cardiac and noncardiac causes of dyspnea in cats

OBJECTIVE: To determine whether plasma cardiac troponin I (cTnI) concentrations can be used to discriminate cardiac from noncardiac causes of dyspnea in cats. DESIGN: Prospective, multicenter study. ANIMALS: Client-owned cats with dyspnea attributable to congestive heart failure (D-CHF; n=31) or to noncardiac causes (D-NCC; n=12). PROCEDURES: For each cat, plasma cTnI concentration was analyzed by use of a solid-phase radial partition immunoassay; values in cats with D-CHF and D-NCC were compared. A receiver operating characteristic curve was analyzed to determine the accuracy of plasma cTnI concentration for diagnosis of D-CHF. RESULTS: Median plasma concentration of cTnI in cats with D-CHF (1.59 ng/mL; range, 0.20 to 30.24 ng/mL) was significantly higher than in cats with D-NCC (0.165 ng/mL; range, 0.01 to 1.42 ng/mL). With regard to the accuracy of plasma cTnI concentration for diagnosis of D-CHF, the area under the receiver operating characteristic curve was 0.84. At plasma concentrations > or = 0.2 ng/mL, cTnI had 100% sensitivity but only 58% specificity for identification of CHF as the cause of dyspnea. At plasma concentrations > or = 1.43 ng/mL, cTnI had 100% specificity and 58% sensitivity for identification of CHF as the cause of dyspnea. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of the derived diagnostic limits, CHF as the cause of dyspnea could be ruled in or ruled out without additional diagnostic testing in > 50% of the study cats. Measurement of plasma cTnI concentration may be clinically useful for differentiation of cardiac from noncardiac causes of dyspnea in cats. (J Am Vet     

Population and survival characteristics of cats with hypertrophic cardiomyopathy: 260 cases (1990-1999)

OBJECTIVE: To determine current population characteristics of, clinical findings in, and survival times for cats with hypertrophic cardiomyopathy (HCM). DESIGN: Retrospective study. ANIMALS: 260 cats with HCM. PROCEDURE: Information was obtained from the medical records. Cats were classified into 1 of 4 clinical groups (congestive heart failure [CHF] group, arterial thromboembolism [ATE] group, syncope group, or cats without clinical signs [subclinical group]) on the basis of the primary clinical signs at the initial examination. RESULTS: 120 cats were classified in the CHF group, 43 in the ATE group, 10 in the syncope group, and 87 in the subclinical group. Antecedent events that may have precipitated CHF included i.v. fluid administration, anesthesia, surgery, and recent corticosteroid administration. Median survival time was 709 days (range, 2 to 4,418 days) for cats that survived > 24 hours. Cats in the subclinical group lived the longest (median survival time, 1,129 days; range, 2 to 3,778 days), followed by cats in the syncope group (654 days; range, 28 to 1,505 days), cats in the CHF group (563 days; range, 2 to 4,418 days), and cats in the ATE group (184 days; range, 2 to 2,278 days). Causes of death included ATE (n = 56), CHF (49), sudden death (13), and noncardiac causes (27). In univariate analyses, survival time was negatively correlated with left atrial size, age, right ventricular enlargement, and thoracentesis. Cats with systolic anterior motion of the mitral valve lived longer than cats without this echocardiographic finding. In multivariate analyses, only age and left atrial size remained significant predictors of survival time. CONCLUSIONS AND CLINICAL RELEVANCE: Although overall survival time for cats with HCM was similar to earlier reports, survival times for cats with CHF or ATE were longer than previously reported.     

A retrospective study of heart disease in doberman pinscher dogs

The prevalence of gross and/or histological cardiac lesions was found to be much greater in Doberman pinscher dogs (16/26 or 62%) than in non-Doberman dogs (124/417 or 30%). At least some of the affected Dobermans were unrelated. Middle aged (mean age 4.7 yr) Dobermans of both sexes (11 M:5F) were affected. Four of the Dobermans with heart lesions had congestive cardiomyopathy; three of these four had congestive heart failure and the other one died suddenly. Prominent gross lesions were ventricular dilation and atrioventricular valvular endocardiosis. Histological lesions noted were prominent myocardial fibrosis, myofiber degeneration with fatty replacement, myofiber vacuolation and arterial intimal cushion formation. A spectrum of myocardial disease exists in Dobermans and clinically overt congestive cardiomyopathy represents one end of this spectrum.     

Dietary patterns of cats with cardiac disease

OBJECTIVE: To determine nutrient intake and dietary patterns in cats with cardiac disease. DESIGN: Prospective study. ANIMALS: 95 cats with congenital cardiac disease or primary cardiomyopathy. PROCEDURES: Owners completed a standardized telephone questionnaire regarding their cat's diet and a 24-hour food recall to determine daily intake of calories, fat, protein, sodium, magnesium, and potassium. RESULTS: Of the 95 cats, 18 (19%) had a history of congestive heart failure and 73 (77%) had no clinical signs of cardiac disease. Fifty-five percent (52/95) of cats had concurrent disease. Inappetance was reported in 38% (36/95) of all cats and in 72% (68/95) of cats with a history of congestive heart failure. Most (57% [54/95]) cats received treats or table scraps on a regular basis. Approximately half the cats were receiving orally administered medications, supplements, or both. Only 34% (32/68) of owners used food to administer medications to cats. Cats consumed more than the Association of American Feed Control Officials (AAFCO) minimums for protein, sodium, potassium, and magnesium, and nearly all cats consumed more than the AAFCO minimum for fat. Daily nutrient intake was variable for all of the nutrients assessed. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary intake in cats with cardiac disease was variable, but results for dietary supplement use, food use for medication administration, and treat feeding were different from those found in a similar study of dogs with cardiac disease. This information may be useful for treating and designing nutritional studies for cats with cardiac disease.     

Measurements of plasma endothelin immunoreactivity in healthy cats and cats with cardiomyopathy

Plasma concentrations of endothelin-1 (ET-1), the most potent endogenous pressor substance discovered to date, are abnormally high in humans with congestive heart failure (CHF), and they correlate with the degree of functional impairment. We sought first to validate a human sandwich ELISA kit that targets that portion of the amino acid sequence that is identical in cats. The assay demonstrated linearity (R2 = .9968) and parallelism (P = .5339), recovery of spiked human ET-1 in cat plasma averaged 98.7%, and intraassay precision had a coefficient of variation <10%. We subsequently determined ET-1 immunoreactivity in healthy cats and in cats with myocardial disease with and without CHF, systemic thromboembolism (STE), or both. Plasma ET-1 immunoreactivity was measured in 12 healthy cats and in 28 cats with primary myocardial disease, including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), or restrictive or unclassified cardiomyopathy (RCM and UCM), respectively. Plasma ET mean (95% CI) concentrations were 0.777 (0.6536-0.924) fmol/mL in the control cats, 1.427 (0.922-2.209) fmol/mL in 12 cats with cardiomyopathy (HCM = 11, RCM/UCM = 1) but without CHF or evidence of STE, and 2.360 (1.666-3.343) fmol/mL in 16 cats with cardiomyopathy (HCM = 8, RCM/UCM = 7, DCM = 1) and CHF (n = 15) or STE (n = 4). Plasma immunoreactivity of ET-1 was significantly higher in cats with myocardial disease without CHF/STE versus normal cats (P < .05) and in cats with myocardial disease with CHF/STE versus normal cats (P < .001).     

Observations on the development of congestive heart failure in Irish wolfhounds with dilated cardiomyopathy

Records of previous electrocardiographic (ECG) and echocardiographic examinations of 39 Irish wolfhounds with cardiac failure, obtained during a 10-year survey, were examined to establish whether previously detected abnormalities might be prognostic indicators for the development of congestive heart failure (CHF) due to dilated cardiomyopathy (DCM) in later life. Eighteen dogs (46 per cent) had had atrial fibrillation (AF) at their first examination. Other ECG abnormalities detected at previous examinations were ventricular and supraventricular premature contractions, first and second degree atrioventricular block, P mitrale and left anterior fascicular and right bundle branch blocks. All 39 dogs had developed AF by the time of onset of CHF. The mean age at which CHF was diagnosed was 77 months in males and 86 months in females. The mean age at which AF was first detected was 45 months in males and 59 months in females, and the mean time from the first detection of AF to CHF was 27 months in males and 24 months in females. Previous echocardiographic examinations in eight dogs, over a period of up to five years, revealed progressive left atrial and left ventricular dilatation. Fractional shortening was reduced to below the normal range at the onset of CHF compared with previous examinations in three cases but increased in five. It appears, therefore, that certain ECG abnormalities, especially AF, and/or progressive ventricular and atrial dilatation, may be indicators of 'occult' DCM in wolfhounds.     

Pacemaker implantation in a ferret (Mustela putorius furo) with third-degree atrioventricular block.

A 7.5-year-old castrated male ferret (Mustela putorius furo) was diagnosed with third-degree atrioventricular (AV) block. A monopolar epicardial pacemaker system was implanted, resulting in a regular, paced cardiac rhythm with third-degree AV block at 140 beats per minute. Over the next 2 months, the ferret developed anorexia, interstitial pneumonia, intermittent diarrhea, and hind-limb weakness and had a slow and progressive recovery. The ferret developed clinical signs of congestive heart failure 4 months after the surgery, resulting in its death 3 weeks later. Necropsy results attributed the death to cardiac failure due to extensive myocardial mineralization. To the authors' knowledge this is the first published report of surgical report of surgical pacemaker implantation in a ferret.     

Indirect determination of nitric oxide in cats with cardiomyopathy and arterial thromboembolism

Objective: To determine nitric oxide concentration in cats with hypertrophic or intermediate forms of cardiomyopathy and arterial thromboembolism (ATE) compared to healthy controls and to determine the association between nitric oxide concentration and the presence of ATE, congestive heart failure (CHF), and echocardiographic measurements. Design: Case–control study. Setting: Veterinary teaching hospital. Animals: Client‐owned cats with cardiomyopathy, cardiomyopathy and ATE, and normal cats. Interventions: None. Measurements: All cats underwent 2‐dimensional and M‐mode echocardiography. Nitric oxide was assessed indirectly by measuring the concentration of plasma nitrite+nitrate (NN), end products of nitric oxide metabolism. Plasma arginine concentration and dietary arginine content were also assessed since arginine is a precursor for nitric oxide production. Main results: Twenty‐six cats with cardiomyopathy, 26 cats with cardiomyopathy and ATE, and 29 nor‐mal cats were enrolled. Compared with healthy controls, median NN concentration was significantly higher in cats with cardiomyopathy and cats with both cardiomyopathy and ATE. There was no difference between cats with cardiomyopathy alone and cats with cardiomyopathy and ATE. Nitrate+ nitrite concen‐tration in cats with cardiac disease was unrelated to the presence of CHF, plasma arginine concentration, or dietary arginine content. In cats with cardiac disease, the left atrial diameter, left ven‐tricular diameter in diastole, and age were negatively correlated with NN concentrations. Conclusions: Nitric oxide concentration is elevated in cats with cardiac disease, but the elevation appears to be independent of ATE and CHF.     

Hypercoagulability in cats with cardiomyopathy

BACKGROUND: Arterial thromboembolism (ATE) is a common complication of feline cardiomyopathy; however, the pathogenesis of ATE is unknown. HYPOTHESIS: Systemic activation of the coagulation cascade (hypercoagulability) and endothelial injury promote ATE in cardiomyopathic cats. ANIMALS: Healthy cats (n = 30) and 3 groups of cardiomyopathic cats: Group (1) left atrial enlargement only (LAE [n = 11]), ie, left atrial to aortic ratio >1.4; Group (2) LAE with spontaneous echocardiographic contrast, atrial thrombi or both (SEC-T [n = 16]); and Group (3) acute ATE with LAE (n = 16). METHODS: Hypercoagulability was defined by 2 or more laboratory abnormalities reflecting coagulation factor excess (high fibrinogen concentration or Factor VIII coagulant activity), inhibitor deficiency (low antithrombin activity), or thrombin generation (high thrombin-antithrombin complex [TAT] and d-dimer concentrations). High von Willebrand factor antigen concentration (vWF : Ag) was considered a marker of endothelial injury. Data were analyzed using nonparametric statistics. RESULTS: The 3 groups of cats with cardiac disease had higher median fibrinogen concentrations than did the healthy cats. Criteria of hypercoagulability were found exclusively in cats with SEC-T (50%) and ATE (56%). Hypercoagulability was not associated with left atrial size or congestive heart failure (CHF). ATE cats had significantly higher median vWF : Ag concentration than did the other groups. CONCLUSION AND CLINICAL IMPORTANCE: Systemic hypercoagulability is evident in many cardiomyopathic cats, often without concurrent CHF or overt ATE. Hypercoagulabilty may represent a risk factor for ATE. High vWF : Ag in ATE cats was attributed to downstream endothelial injury from the occlusive thrombus.     

Arterial thromboembolism in cats: acute crisis in 127 cases (1992-2001) and long-term management with low-dose aspirin in 24 cases

Records of 127 cats with arterial thromboembolism (ATE) were reviewed. Abyssinian, Birman, Ragdoll, and male cats were overrepresented. Tachypnea (91%), hypothermia (66%), and absent limb motor function (66%) were common. Of 90 cats with diagnostics performed, underlying diseases were hyperthyroidism (12), cardiomyopathy (dilated [8], unclassified [33], hypertrophic obstructive [5], hypertrophic [19]), neoplasia (6), other (4), and none (3). Common abnormalities were left atrial enlargement (93%), congestive heart failure (CHF, 44%), and arrhythmias (44%). Of cats without CHF, 89% were tachypneic. Common biochemical abnormalities were hyperglycemia, azotemia, and abnormally high serum concentrations of muscle enzymes. Of 87 cats treated for acute limb ATE, 39 (45%) survived to be discharged. Significant differences were found between survivors and nonsurvivors for temperature (P < .00001), heart rate (P = .038), serum phosphorus concentration (P = .024), motor function (P = .008), and number of limbs affected (P = .001). No significant difference was found between survivors and nonsurvivors when compared by age, respiratory rate, other biochemical analytes, or concurrent CHE A logistic regression model based on rectal temperature predicted a 50% probability of survival at 98.9 degrees F (37.2 degrees C). Median survival time (MST) for discharged cats was 117 days. Eleven cats had ATE recurrences, and 5 cats developed limb problems. Cats with CHF (MST: 77 days) had significantly shorter survival than cats without CHF (MST: 223 days; P = .016). No significant difference was found in survival or recurrence rate between cats receiving high-dose aspirin (> or = 40 mg/cat q72h) and cats receiving low-dose aspirin (5 mg/cat q72h). Adverse effects were less frequent and milder for the lower dosage.     

Evaluation of acute congestive heart failure in dogs and cats: 145 cases (2007–2008)

Objective – To characterize the clinical presentation, management, and in‐hospital outcomes of dogs and cats diagnosed with acute congestive heart failure (CHF). Design – Retrospective study of animals seen between January 2007 and May 2008. Setting – Emergency service at a university teaching hospital. Animals – Ninety dogs and 55 cats with CHF. Measurements and Main Results – Patient characteristics, including age, clinical signs, clinicopathologic abnormalities, diagnostic testing, and outcome were recorded. Forty‐eight of the animals already were receiving cardiac medications at the time of presentation. The most common diseases represented were chronic valvular disease and cardiomyopathies. Cats had significantly lower median body temperature at admission compared with dogs (P<0.001). The most common abnormalities were elevated lactate (64%), elevated BUN (52%), hypochloremia (31%), hyperglycemia (27%), and elevated liver enzymes (26%). Many of these became even more prevalent during hospitalization. One hundred and sixteen animals were discharged from the hospital, for a survival rate of 80%. There was no survival difference between dogs and cats (P=0.39). Dogs that developed hypokalemia during hospital stay (P=0.04) were more likely to survive compared with those without hypokalemia and initial body temperature was lower for those cats that did not survive (P=0.02). Of those that did not survive, the majority were euthanized (n=25), while 4 dogs died. Conclusions – Dogs and cats presented to the emergency service with CHF had a high survival rate. In cats, initial body temperature was lower for those cats that did not survive. Although clinicopathologic abnormalities were common in both species, only dogs with hypokalemia had improved survival to hospital discharge.