Effects of pimobendan on left atrial transport function in cats

Abstract

Background Arterial thromboembolism is a sequela of hypertrophic cardiomyopathy (HCM) in cats related to left atrial (LA) enlargement and dysfunction. Hypothesis Pimobendan improves LA transport function in cats. Animals Twenty‐two client‐owned cats with HCM and 11 healthy cats. Methods Prospective, double‐blind, randomized, placebo‐controlled clinical cohort study. Cats were randomized to receive either pimobendan (0.25 mg/kg PO q12h) or placebo for 4 to 7 days. Nineteen echocardiographic variables of LA size and function were evaluated. Statistical comparisons included t tests, analysis of variance, and multivariable analyses. Results Peak velocity of left auricular appendage flow (LAapp peak; mean ± SD, 0.85 ± 0.20 vs 0.71 ± 0.22 m/s; P = .01), maximum LA volume (P = .03), LA total emptying volume (P = .03), peak velocity of late diastolic transmitral flow (A peak velocity; 0.77 ± 0.12 vs 0.62 ± 0.17 m/s; P = .05), and A velocity time integral (A VTI; 3.05 ± 0.69 vs 3.37 ± 0.49; P = .05) were increased after pimobendan. Mean change after pimobendan was larger in cats with HCM compared to healthy cats for LA fractional shortening (2.1% vs −2.1%; P = .05), A VTI (0.58 vs 0.01 cm; P = .01), LAapp peak (0.20 vs 0.02 m/s; P = .02), LA kinetic energy (3.51 vs −0.10 kdynes‐cm; P = .05), and LA ejection force (1.93 vs −0.07 kdynes; P = .01) in the multivariable model. The stronger effect of pimobendan in cats with HCM was independent of LA size. Conclusions and Clinical Importance We identified positive, albeit minor, effects of pimobendan on LA function in cats with HCM. Whether or not treatment with pimobendan decreases the risk of cardiogenic embolism deserves further study.

Aortic annular plane systolic excursion in cats with hypertrophic cardiomyopathy

“…We did not have enough data to assess if any medications received affected AAPSE, such as furosemide or pimobendan, which could have had an effect on LV preload and left atrial and LV systolic function, respectively, and thus an impact on AAPSE values. [46][47][48] In conclusion, we found that AAPSE was lower in cats with HCM, and cats with HCM stage C have the lowest values of AAPSE. This might be a new measurement of LV systolic performance, most likely related to longitudinally systolic function.…”

“…We did not have enough data to assess if any medications received affected AAPSE, such as furosemide or pimobendan, which could have had an effect on LV preload and left atrial and LV systolic function, respectively, and thus an impact on AAPSE values. 46 , 47 , 48 …”

Haemodynamic Effects of Pimobendan during General Anaesthesia in Healthy Senior Dogs: A Prospective, Randomised, Triple-Blinded, Placebo-Controlled Clinical Study

“…This parameter is widely used to assess contractility in several species [ 39 , 40 , 41 ]. The effects of pimobendan on inotropism appear less pronounced in anaesthetised dogs than in awake dogs [ 38 ]. In the present study, PV and MA were used to assess changes in inotropism: PV is the maximum velocity of blood in the aorta, and MA is the slope of the aortic velocity curve.…”

Клінічні Випадки Гіпертрофічної Кардіоміопатії У Котів

“…Аритмії виявляли лише у трьох (18 %). Згідно з дослідженнями авторів [19][20], наявність шуму в серці підвищує вірогідність гіпертрофічної кардіоміопатії у котів порівняно з тваринами без шуму.…”