Introduction

Degenerative mitral valve disease (DMVD) in dogs leads to increase in left-ventricular filling pressure and left-sided congestive heart failure (CHF). Pulsed-wave echocardiography of transmitral flow indirectly evaluates left-ventricular diastolic function. CHF can be predicted by alterations in diastolic indices and may lead to cardiovascular-renal disorders.

Objectives

Quantify the frequency of diastolic dysfunction in DMVD and evaluate the correlation between diastolic function and renal function indices.

Methods

One hundred and two dogs with DMVD allocated into four groups according to the degree of hemodynamic repercussion of the disease: normal left atrium (LA) group (NLA, n=40), mildly enlarged LA (MiLA, n=25), moderately enlarged LA (MoLA, n=13) and severely enlarged LA (SLA, n=24). Renal function (creatinine and BUN) and echocardiographic diastolic function (E and A peak waves, E:A ratio, isovolumic relaxation time [IVRT] and E:IVRT ratio) were evaluated. Diastolic function was classified as normal (2.0≤ E:A≥1.0, normal E and A waves), relaxation delay pattern (E:A <1.0), pseudonormal pattern (2.0≤E:A≥1.0, increased E and A waves) or restrictive pattern (E:A>2.0).

Results

Diastolic dysfunction occurrence was 25% in NLA group, 20% in MiLA group, 38,5% in MoLA group and 87,5% in SLA group (4.2% relaxation delay pattern, 37.5% pseudonormal, 45.8% restrictive). Pearson correlation did not demonstrate relation between renal function and diastolic function indices.

Conclusions

Diastolic dysfunction is more common in advanced stages of DMVD and, although useful to estimate the emergence of CHF, it seems not to predict the development of concomitant renal disease.