Natural History of Arrhythmogenic Right Ventricular Cardiomyopathy in the Boxer Dog: A Prospective Study

Abstract

BackgroundBoxer arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease that may result in sudden death or heart failure.Hypothesis/objectivesTo prospectively study the natural history of Boxer ARVC.Animals72 dogs (49 ARVC, 23 controls).MethodsBoxers >1 year of age were recruited for annual reevaluation. Controls were defined as being ≥6 years of age and having <50 ventricular premature complex (VPCs)/24 h. ARVC was defined as ≥300 VPCs/24 h in the absence of other disease. Dogs were genotyped for the striatin deletion when possible. Descriptive statistics were determined for age; VPC number; annual change in VPC number; and left ventricular (LV) echocardiographic dimensions. Survival time was calculated.Results Controls: median age of 7 years (range, 6–10); number of VPCs 12 (range, 4–32). Median time in study of 6 years (range, 2–9). Seventeen of 23 were genotyped (5 positive, 12 negative). ARVC: median age of diagnosis of 6 (range, 1–11). Median time in study 5 years (range, 3–8). A total of 33% were syncopal and 43/49 were genotyped (36 positive, 7 negative). Yearly change in VPCs was 46 (range, −7,699 to 33,524). Annual percentage change in LV dimensions was 0, and change in fractional shortening (FS%) was 2%. Two dogs had FS% <20%. Although ARVC dogs died suddenly, there was no difference in survival time between groups. ARVC median age of survival was 11 years, and for controls was 10 years.Conclusions/Clinical ImportanceArrhythmogenic right ventricular cardiomyopathy is a disease of middle age and frequently is associated with the striatin deletion. Syncope occurs in approximately 1/3 of affected dogs; systolic dysfunction is uncommon. The prognosis in many affected dogs is good.

Evaluation of echocardiography and cardiac biomarker concentrations in dogs with gastric dilatation volvulus

“…At the time of presentation, 4 dogs (18%) had ventricular arrhythmias, but 15 dogs (68%) were identified to have ventricular arrhythmias during the course of hospitalization. Categories of ventricular arrhythmias during hospitalization included single VPCs (Grade 1; n = 9; 41%) and R‐on‐T phenomenon or ventricular tachycardia (Grade 4; n = 6; 27%). Seven dogs (32%) had no arrhythmias during hospitalization (Grade 0).…”

“…Box plots of the highest recorded concentrations of cardiac troponin I (cTnI; a), N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP; b), and lactate (c) in 22 dogs with gastric dilatation volvulus with different categories of ventricular arrhythmias. Ventricular arrhythmias were categorized using a previously published system: 0 = no ventricular premature complexes (VPCs); 1 = single VPCs; 2 = bigeminy or trigeminy; 3 = couplets or triplets; and 4 = R‐on‐T phenomenon or ventricular tachycardia. No dogs were identified with Grade 2 or 3 ventricular arrhythmias.…”

“…Dogs’ cardiac rhythms were recorded at the time of presentation by ECG and postoperatively by continuous ECG monitoring . Ventricular arrhythmias were categorized using a previously published system: 0 = no ventricular premature complexes (VPCs), 1 = single VPCs, 2 = bigeminy or trigeminy, 3 = couplets or triplets, and 4 = R‐on‐T phenomenon or ventricular tachycardia.…”

Risk factors and select cardiac characteristics in dogs naturally infected withTrypanosoma cruzipresenting to a teaching hospital in Texas

“…In this study, we found the highest prevalence in non‐sporting (29%), toy (24%), and herding (21%) breed groups, and in multiple breeds with a predisposition for acquired heart diseases that result in a similar phenotype as Chagas cardiomyopathy. For example, German Shepherds (30% positive in this population) that can develop breed‐related inherited ventricular arrhythmias and sudden death at a very young age; Doberman Pinschers (25% positive) predisposed to idiopathic dilated cardiomyopathy characterized by cardiac enlargement, ventricular myocardial dysfunction, ventricular arrhythmias, CHF, and sudden death; and Bulldogs (54% positive) and Boxers (7% positive) that can develop arrhythmogenic right ventricular cardiomyopathy . This is an important point to consider when making a diagnosis of a heart disease that can mimic Chagas disease in a region known to have Chagas disease, as discrimination between Chagas disease and other etiologies of arrhythmias and ventricular systolic dysfunction could be difficult.…”

Valor prognóstico da variabilidade da frequência cardíaca e da eletrocardiografia ambulatorial em cães Boxer com cardiomiopatia arritmogênica do ventrículo direito

“…Another important limitation was our unavailability to perform a striatin genetic mutation test in the studied Boxer dogs; the application of this test might have more precisely elucidated which animals were truly affected by Boxer ARVC. The use of an arbitrary cutoff value of VPCs on a single Holter examination for the classification of dogs as having ARVC may have led to misclassification of some patients, although the values used in this study were based on previous studies (Stern et al, 2010, Meurs et al, 2014.…”