cardiovascular-agents and Cat-Diseases

The natural progression of cardiomyopathy in cats can lead to congestive heart failure. This review enumerates commonly and uncommonly used medications that can be used for the long-term treatment of cats that have positively responded to initial management of acute heart failure. The advantages, drawbacks, and authors' preferred approach are presented for each medication.

Topics: Animals; Cardiomyopathies; Cardiovascular Agents; Cat Diseases; Cats

Restrictive cardiomyopathy (RCM) is a common myocardial disease in cats, characterized by diastolic dysfunction and atrial enlargement without myocardial hypertrophy. Especially, endomyocardial form of RCM, one of the subtypes in RCM, is characterized by endocardial fibrosis, endocardial scar bridging the interventricular septum and left ventricular (LV) free wall, and deformation and distortion of the LV. However, it is unclear how the myocardial dysfunction and the endocardial scar contribute to the pathophysiology of RCM disease progression.. A 3 years and 2 months old, intact male, Domestic shorthaired cat was presented for consultation of cardiac murmur. At the first visit (day 0), the notable abnormal finding was echocardiography-derived chordae tendineae-like structure bridging the interventricular septum and the LV free wall, resulting high-speed blood flow in the left ventricle. Electrocardiography, thoracic radiography and noninvasive blood pressure measurements were normal. No left atrial enlargement was observed, and LV inflow velocity showed an abnormal relaxation pattern. Although there was no abnormality in tissue Doppler imaging-derived myocardial velocity, two-dimensional speckle tracking echocardiography (2D-STE) revealed a decrease in the LV longitudinal strain and an increase in endocardial to epicardial ratio of the LV circumferential strain on day 0. On day 468, obvious left atrium enlargement and smoke like echo in the left atrium were observed. The LV inflow velocity was fused, and the tissue Doppler imaging-derived early-diastolic myocardial velocity of the septal mitral annulus decreased. Regarding 2D-STE, LV circumferential strain was further decreased, and right ventricular strain was additionally decreased. Although the general condition was good, we made a clinical diagnosis of endomyocardial RCM based on the above findings. On day 503, the cat showed the radiographic evidence of pulmonary edema and congestive heart failure signs.. Cats with abnormal LV structure and associated myocardial dysfunction like this case needs careful observation. Additionally, 2D-STE indices may be useful for early detection of myocardial dysfunction in feline RCM.

Topics: Animals; Cardiomyopathies; Cardiovascular Agents; Cat Diseases; Cats; Endomyocardial Fibrosis; Heart Failure; Male

Double-outlet right atrium (DORA) is a type of atrioventricular septal defect that is described as an extreme leftward deviation of the lower portion of the interatrial septum, resulting in insertion into the atrial wall left and posterior to the mitral orifice. This rare anomaly, which has been reported in humans and only just recently in cats, was identified by transthoracic echocardiography in a 9 year-old cat that was presented for further evaluation of a tachyarrhythmia and cardiomegaly. This case report describes the diagnostic findings in this cat and summarizes the anatomy, classification and clinical consequences of this rare congenital heart defect.

Topics: Animals; Cardiovascular Agents; Cat Diseases; Cats; Echocardiography; Female; Furosemide; Heart Atria; Heart Septal Defects

To evaluate the effects of the pacemaker funny current (I(f)) inhibitor ivabradine on heart rate (HR), left ventricular (LV) systolic and diastolic function, and left atrial performance in healthy cats and cats with hypertrophic cardiomyopathy (HCM).. 6 healthy cats and 6 cats with subclinical HCM.. Anesthetized cats underwent cardiac catheterization and were studied over a range of hemodynamic states induced by treatment with esmolol (200 to 400 μg/kg/min, IV), esmolol and dobutamine (5 μg/kg/min, IV), ivabradine (0.3 mg/kg, IV), and ivabradine and dobutamine. Left ventricular systolic and diastolic function, cardiac output, and left atrial function were studied via catheter-based methods and echocardiography.. Treatment with ivabradine resulted in a significant reduction of HR, rate-pressure product, and LV contractile function and a significant increase in LV end-diastolic pressure, LV end-diastolic wall stress, and LV relaxation time constant (tau) in cats with HCM. Concurrent administration of ivabradine and dobutamine resulted in a significant increase of LV contractility and lusitropy, with blunted chronotropic effects of the catecholamine. Left atrial performance was not significantly altered by ivabradine in cats with HCM. Regression analysis revealed an association between maximum rate of LV pressure rise and tau in cats with HCM.. Ivabradine had significant effects on several cardiovascular variables in anesthetized cats with HCM. Studies in awake cats with HCM are needed to clinically validate these findings.

Topics: Adrenergic beta-1 Receptor Agonists; Adrenergic beta-1 Receptor Antagonists; Animals; Benzazepines; Blood Pressure; Cardiomyopathy, Hypertrophic; Cardiovascular Agents; Cat Diseases; Cats; Dobutamine; Dose-Response Relationship, Drug; Heart Rate; Ivabradine; Propanolamines; Ventricular Function, Left

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method for the measurement of the novel heart rate-lowering drug ivabradine and its major metabolite, S-18982, was cross-validated in the plasma of eight healthy cats. Plasma concentrations were then determined after single and repeated oral administration of ivabradine. Individual plasma concentrations versus time from each cat were used in compartmental analysis using the commercially available software WinNonlin. Both ivabradine and S-18982 reached their maximum concentrations of 103.33 and 3.86 ng/mL within 1 h. Following repeated administration, areas under the plasma concentration-time curves for ivabradine and S-18982 did not significantly increase. Two-compartmental and one-compartmental models with first-order input and elimination provided the best fit to the data for ivabradine and S-18982, respectively. Both models were combined to produce a single 4-compartment model characterizing ivabradine and S-18982 pharmacokinetics. The results of this study indicate that repeated oral doses of ivabradine produced plasma drug concentrations suitable for 12-h dosing intervals in healthy cats. Furthermore, the analytical assay and combined ivabradine/S-18982 model provide tools for further evaluation of ivabradine pharmacokinetics and pharmacodynamics in future studies in cats.

Topics: Administration, Oral; Animals; Benzazepines; Cardiovascular Agents; Cat Diseases; Cats; Chromatography, Liquid; Female; Ivabradine; Reproducibility of Results; Tandem Mass Spectrometry

Responses (473) were collated from a questionnaire sent to 5054 veterinarians in Australia enquiring about drug preferences for treating cardiac disease in dogs and cats. When treating a small breed dog with endocardiosis and mild left congestive heart failure, 74% of 472 respondents used a diuretic, 67% a theophylline derivative, 27% a vasodilator and 20% a positive inotrope. Frusemide was the preferred diuretic and digoxin the preferred inotrope, but vasodilator use varied. Low sodium diets were "often recommended" by 71% of respondents. Propranolol was preferred to diltiazem for treating feline hypertrophic cardiomyopathy. Digoxin was clearly preferred for treating supraventricular dysrhythmias, while lignocaine and digoxin were preferred equally for ventricular dysrhythmias. Respondents appeared more willing than US veterinarians to use theophylline derivatives and prasozin, and less inclined to employ nitrates, hydralazine, inotropes other than digoxin, and low sodium diets.

Topics: Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Australia; Cardiotonic Agents; Cardiovascular Agents; Cat Diseases; Cats; Digoxin; Diuretics; Dog Diseases; Dogs; Furosemide; Heart Diseases; Heart Failure; Lidocaine; Propranolol; Surveys and Questionnaires; Vasodilator Agents