Background: Associations of age and heart rate with blood flow velocities and durations assessed by pulsed-wave (PW) Doppler echocardiography in cats are incompletely understood.Objectives: To determine the effects of age and heart rate on blood flow velocities and durations of cardiac events obtained by PW Doppler echocardiography in healthy, nonsedated cats.Animals: A convenience sample of 87 healthy, nonsedated cats aged 3 months to 19 years. Methods: Prospective, observational study. PW Doppler measurements were obtained by echocardiography. Association of age and heart rate with PW Doppler values was evaluated by simple and multiple linear regressions and ANCOVA.Results: Significant weak positive relationships were found between age and isovolumic relaxation time (IVRT) (R 2 5 0.18; P .001), and between age and duration of pulmonary venous retrograde flow (R 2 5 0.07; P 5 .041). There was a significant weak negative relationship between age and transmitral peak early diastolic velocity (R 2 5 0.19; P .001). Age and heart rate were significantly related to pulmonary venous peak systolic velocity (R 2 5 0.13; P 5 .008). Heart rate affected transmitral peak late diastolic velocity (R 2 5 0.11; P 5 .006). After adjusting for heart rate effect, the PW Doppler variables that were significantly different between age groups were transmitral peak early diastolic velocity (P .001), duration of transmitral late diastolic flow (P .001), IVRT (P .001), and the ratio of duration of transmitral late diastolic flow to duration of pulmonary venous retrograde flow (P 5 .029).Conclusions and Clinical Importance: The association of several PW Doppler-derived variables and age and heart rate is weak and not clinically important.
Valvular heart disease accounts for over 20 000 deaths and 90 000 hospitalizations yearly in the United States. Myxomatous valve disease (MVD) is the most common disease of the mitral valve in humans and dogs. MVD is pathologically identical in these species and its pathogenesis is poorly understood. The objectives of this study were to (i) develop proteomic methodology suitable for analysis of extracellular matrix-rich heart valve tissues and (ii) survey over- and under-expressed proteins that could provide mechanistic clues into the pathogenesis of MVD. Normal, early-stage, and late-stage myxomatous mitral valves from dogs were studied. A shotgun proteomic analysis was used to quantify differential protein expression. Proteins were classified by function and clustered according to differential expression patterns. More than 300 proteins, with 117 of those being differentially expressed, were identified. Hierarchical sample clustering of differential protein profiles showed that early- and late-stage valves were closely related. This finding suggests that proteome changes occur in early degeneration stages and these persist in late stages, characterizing a diseased proteome that is distinct from normal. Shotgun proteome analysis of matrix-rich canine heart valves is feasible, and should be applicable to human heart valves. This study provides a basis for future investigations into the pathogenesis of MVD.
Serotonin and serotonergic drugs are known to cause myxomatous‐like valvulopathy, but the role of serotonin in spontaneous myxomatous valve disease (MVD) is unknown. The study objective was to test the hypothesis that autocrine serotonin signaling mediates spontaneous MVD.METHODSNormal and myxomatous mitral valves from dogs were studied. Expression of serotonin 2B receptor (5HT2BR), tryptophan hydroxylase 1 (TPH1), serotonin transmembrane transporter (SERT), total and phosphorylated extracellular signaling‐regulated kinase (ERK)1/2 were studied by immunohistochemistry and immunoblot analysis.RESULTSBoth 5HT2BR and TPH1, the key serotonin synthetic enzyme, were increased in myxomatous valves; whereas SERT, a key protein in serotonin metabolism, was decreased in myxomatous valves. Phosphorylated, but not total, ERK1/2 was increased in myxomatous valves consistent with enhanced active serotonin signaling.CONCLUSIONExpression patterns for key serotonin signaling proteins suggest that autocrine serotonin signaling mediates spontaneous canine MVD. Research supported by the Heart to Heart foundation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.