Doppler Echocardiographic Assessment Of Acquired Heart Diseases In Dogs
| dc.contributor.advisor | Nagarajan, B. | |
| dc.contributor.advisor | Kumanan, K. | |
| dc.contributor.advisor | Nambi, A.P. | |
| dc.contributor.advisor | Ramesh, S. | |
| dc.contributor.author | Thirunavukkarasu, P. | |
| dc.contributor.author | TANUVAS | |
| dc.date.accessioned | 2016-05-24T16:41:19Z | |
| dc.date.available | 2016-05-24T16:41:19Z | |
| dc.date.issued | 2014 | |
| dc.description.abstract | Acquired heart diseases (AHD) are common and often fatal when it leads to CHF in dogs and it occurs most often secondary to degenerative mitral valve disease (MVD), dilated cardiomyopathy (DCM), pericardial diseases and Hypertrophic cardiomyopathy (HCM). Early recognition of AHD is of clinical importance. Tissue Doppler echocardiography is an ideal tool to evaluate patients with acquired heart diseases, offering the potential to improve early identification and management of AHDS. The objectives of this study were to quantify the global and regional myocardial function by Tissue Doppler echocardiography in acquired heart diseases of dogs; to compare the diagnostic efficacy of different modes of Tissue Doppler echocardiography in dogs; and to establish the usefulness of biochemical marker in diagnosis of acquired heart diseases in dogs. 106 animals with acquired heart diseases were selected based on echocardiographic findings from the animals that were brought to MVC teaching hospital and they were grouped as apparently healthy dogs, DCM, MVD, Pericardial diseases and HCM groups. Parameters of the study included Prevalence analysis, Medical history, Clinical presentation, Baseline Haematology panel, Baseline serum biochemistry panel, Radiography, Doppler BP, ECG, Echocardiographic indices such as 2-D echocardiographic indices, M-Mode Echocardiographic indices and Colour flow Doppler, Tissue Doppler Imaging and NT-proBNP Assay. The incidence of AHDs was found to be 0.37 per centin the five semester study period. Labradors and Spitz were found to be commonly affected with DCM and MVD respectively. Older male dogs were found to be more commonly affected. The observed chief complaints included inappetance, exercise intolerance, abdominal enlargement, syncope and weakness. Tachycardia, ascites and murmurs were the common clinical signs in all the groups of AHDs. Haematological assessment showed no significant changes. Serum biochemical assessment showed significant hypernatremia in all groups except HCM. Radiographic signs of AHDs included cardiomegaly, pulmonary oedema and left atrial enlargement. Dogs with DCM and pericardial effusion had significantly elevated VHS and confirmed the presence of acquired heart disease. ECG findings in AHDs were the DCM dogs had characteristic arrhythmic pattern of atrial fibrillation in 20.69 per cent cases and atrial flutter in 8.62 per cent of cases. MVD group dogs had atrial enlargement in 51.28 per cent; pericardial effusion group had low voltage QRS complex and electrical alternans in 83.33 per cent; and HCM group had ventricular enlargement in 100.00 per cent cases. Echocardiographic findings in DCM were LV dilatation, LA dilatation, increased LA/Ao ratio, decreased LVFW and septal thickness, decreased FS, increased LVIDd &LVIDs, increased EPSS and secondary regurgitation of mitral valve and Tricuspid valve; and in MVD were LA dilatation, increased LA/Ao ratio, FS<60 per cent with cardiac failure were identified and mild, moderate and severe MR was found in colour flow Doppler;in pericardial effusion were echo-free space around ventricular chambers, Right Atrial collapse indicating tamponade; and in HCM were LV hypertrophy, SAM and increased FS were observed. In pulsed wave tissue Doppler highly significant decrease in Sm and Em/Am ratio all groups; and significant decrease in Em in all groups were observed; and significant increase in Am in pericardial effusion and HCM were observed. Very typical Em/Am ratio reversal (Em/AM<1) was observed in pericardial effusion and HCM group. In NT-proBNP assay a highly significant increase in levels was observed in DCM, MVD with systolic failure, MVD without systolic failure and in occult cardiac diseases which indicated that this marker is highly sensitive and specific for cardiac diseases. Post-mortem examination of DCM dogs reveals the heart was enlarged, globular, and flabby in appearance with rounded apex due to generalized ventricular dilatation on gross pathology and on transverse biventricular slice of heart the marked dilatation of lumen, attenuation of papillary muscles and thinning of free walls of ventricles were observed. On histopathology left ventricular myocardium showed attenuated wavy fibre type of change. In this study the following conclusions made were Tissue Doppler Echocardiography of acquired heart diseases the regional and global velocities were highly significantly decreased in dogs; Pulsed wave Tissue Doppler Echocardiography is very effective in assessing the peak myocardial velocities in real time, when compare to 2D Tissue Doppler Echocardiography and Colour M-mode Tissue Doppler Echocardiography in dogs and the cardiac biomarker NT-proBNP was very effective and specific marker and very useful in diagnosing and categorizing the cardiac diseases in dogs. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/66286 | |
| dc.language.iso | en | en_US |
| dc.publisher | Tamil Nadu Veterinary and Animal Sciences University | en_US |
| dc.sub | Veterinary Clinical Medicine | |
| dc.subject | Echocardiography | en_US |
| dc.subject | Tissue Doppler Imaging | en_US |
| dc.subject | NT-proBNP | en_US |
| dc.subject | Dogs | en_US |
| dc.these.type | Ph.D | |
| dc.title | Doppler Echocardiographic Assessment Of Acquired Heart Diseases In Dogs | en_US |
| dc.type | Thesis | en_US |