title: Hypovolemia induced systolic anterior motion of the mitral valve in two dogs.
abstract: Systolic anterior (septal) motion of the mitral valve (SAM) is a common secondary phenomenon in hypertrophic cardiomyopathy (HCM) in people and cats. In humans, it is increasingly recognized that SAM may be found in other cardiac and non-cardiac disease states. In small animal cardiology, SAM unassociated with HCM has been described in dogs with mitral valve dysplasia and right ventricular pressure overload. In this report, we describe two cases of dogs where transient SAM was caused by hypovolemia. When SAM was present both dogs showed pseudohypertrophy and tachycardia. Important factors in the genesis of SAM in this scenario are probably hypovolemia induced changes in left ventricular geometry affecting the orientation of the mitral valve apparatus combined with elevated catecholamine levels. SAM associated with increased wall thickness is not pathognomonic of HCM; this observation is of particular clinical importance when extrapolated to species where HCM is highly prevalent, e.g., cats. An echocardiographic diagnosis should always be evaluated together with full clinical assessment of history and physical examination.
authors.affiliation: Division of Cardiology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zürich, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Hammes
authors.affiliation: Division of Cardiology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zürich, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Novo Matos
authors.affiliation: Division of Cardiology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zürich, Switzerland; Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, via Tolara di Sopra 50, 40064 Ozzano Emilia (BO), Italy.
authors.forename: M
authors.initials: M
authors.lastname: Baron Toaldo
authors.affiliation: Division of Cardiology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zürich, Switzerland. Electronic address: tglaus@vetclinics.uzh.ch.
authors.forename: T
authors.initials: T
authors.lastname: Glaus
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000209:etiology*; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary; D006349:Heart Valve Diseases / Q000209:etiology / Q000662:veterinary*; D020896:Hypovolemia / Q000150:complications / Q000662:veterinary*; D008943:Mitral Valve
keywords: Canine; Echocardiography; HCM; Pseudohypertrophy; SAM