Objective—To evaluate the use of retrospectively ECG-gated, contrast-enhanced, multi-detector row computed tomography (MDCT) for assessment of left ventricular function in dogs and to compare the results with those obtained by use of 2-D and M-mode echocardiographc techniques.
Animals—10 healthy Beagles.
Procedures—Dogs underwent MDCT (performed by use of a 64-detector row CT system) and echocardiography under general anesthesia. Left ventricular end-systolic volume (ESV), end-diastolic volume (EDV), and ejection fraction (EF) were determined in MDCT-generated multiplanar reformatted images by use of Simpson and biplane area-length calculation methods. Results were compared with left ventricular ESV, EDV, and EF determined in echocardiographc images by use of Teichholz and bullet method calculations. Results were evaluated via Deming regression analysis and Pearson correlation tests. Bland-Altman analysis was used to assess limits of agreement and systematic errors between the 2 methods.
Results—Mean values for EDV and ESV determined by use of MDCT were highly correlated with those determined by use of echocardiography, regardless of the calculation methods compared (r = 0.91 to 0.96); volumes determined by use of MDCT appeared to be higher than those determined by use of echocardiography, although most differences were nonsignificant. Mean EF determined by use of MDCT with the Simpson calculation method was highly correlated with that determined by use of echocardiography with bullet method calculations (r = 0.90).
Conclusions and Clinical Relevance—Results suggested that assessment of left ventricular volume and function in dogs is feasible with MDCT. To estimate left ventricular EF with MDCT. use of the Simpson calculation method is advised.
Objective—To quantify left ventricle (LV) volumes by use of 1-D, 2-D, and 3-D echocardiography versus MRI in dogs.
Animals—10 healthy Beagles.
Procedures—During anesthesia, each dog underwent an echocardiographic examination via the Teichholz method, performed on the basis of standard M-mode frames (1-D); the monoplane Simpson method of disk (via 2-D loops); real-time triplane echocardiography (RTTPE) with a 3-D probe; and real-time 3-D echocardiography with a 3-D probe. Afterward, cardiac MRI was performed. Values for the LV end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were compared between each echocardiographic method and the reference method (cardiac MRI).
Results—No significant differences for EDV, ESV, and EF were detected between RTTPE and cardiac MRI. Excellent correlations (r = 0.97, 0.98, and 0.95 for EDV, ESV, and EF, respectively) were found between RTTPE and values for cardiac MRI. The other echocardiographic methods yielded values significantly different from cardiac MRI and results correlated less well with results of cardiac MRI for EDV, ESV, and EF. Use of the Teichholz method resulted in LV volume overestimation, whereas the Simpson method of disk and real-time 3-D echocardiography significantly underestimated LV volumes.
Conclusions and Clinical Relevance—Use of RTTPE yielded excellent correlations and nonsignificant differences with cardiac MRI and is a suitable method for routine veterinary cardiac examination.
Objective—To determine whether plasma N-terminal proatrial natriuretic peptide (NT-proANP) concentration could predict the outcome (survival duration) of cats with cardiomyopathy (CM).
Animals—51 cats with CM (25 with and 26 without congestive heart failure [CHF]) and 17 healthy cats.
Procedures—Cats were thoroughly examined and assigned to 1 of 3 groups (control, CM with CHF, and CM alone). Plasma NT-proANP concentrations were measured by use of a human proANP(1-98) ELISA. Survival durations were compared between CM groups.
Results—Plasma NT-proANP concentrations differed significantly among the 3 groups, and survival durations differed significantly between the 2 CM groups. Median (range) NT-proANP concentration was 413 fmol/mL (52 to 940 fmol/mL) in the control group, 1,254 fmol/mL (167 to 2,818 fmol/mL) in the CM alone group, and 3,208 fmol/mL (1,189 to 15,462 fmol/mL) in the CM with CHF group. At a cutoff of 517 fmol/mL, NT-proANP concentration had a sensitivity of 90% and specificity of 82% for detecting CM. Multivariate analysis revealed that only the variable left atrium-to-aortic diameter ratio was a significant predictor of survival duration.
Conclusions and Clinical Relevance—Plasma NT-proANP concentration may have potential as a testing marker for distinguishing healthy cats from cats with CM. It may also be useful for distinguishing CM cats with CHF from those without CHF The value of NT-proANP concentration as a predictor of survival duration was not supported in this study and requires further evaluation. (J Am Vet Med Assoc 2010;237:665-672)