Selected hematological, biochemical, and echocardiographic variables as predictors of survival in canine patients with myxomatous mitral valve disease and congestive heart failure.

INTRODUCTION/OBJECTIVES: We investigated the association of breed, age, weight, duration of therapy, and selected blood and echocardiographic variables with the survival of dogs with congestive heart failure (CHF) due to myxomatous mitral valve disease. We also sought to identify differences in selected echocardiographic and routine blood variables between dogs with stable and unstable CHF and between hospitalized and non-hospitalized patients. ANIMALS, MATERIALS AND METHODS: This retrospective study included dogs with a complete cardiovascular workup. Blood analysis and the initial and final echocardiographic results were included. Covariates were analyzed using Cox proportional hazards models. RESULTS: One hundred sixty-five dogs with myxomatous mitral valve disease were evaluated in this study: 96 stable patients and 69 unstable CHF patients. In total, 107 dogs (64.8%) died, and 58 (35.2%) were censored. The median survival time of the dogs that died was 11.5 months (range 11 days to 4.3 years). Unstable CHF patients had significantly higher neutrophils and lower potassium concentrations than stable CHF patients, and hospitalized patients had higher white blood cell, neutrophil, and monocyte counts and urea and creatinine concentrations than non-hospitalized patients. Variables negatively associated with survival were older age, unstable CHF, duration of therapy, white blood cell count, urea concentration, and left atrium to aorta ratio. Chihuahuas had a lower risk of death. CONCLUSIONS: Selected blood and echocardiographic variables distinguish dogs with stable and unstable CHF and predict survival.

Echocardiographic parameters in French Bulldogs, Pugs and Boston Terriers with brachycephalic obstructive airways syndrome.

BACKGROUND: In this prospective study, we hypothesized that dogs with signs of brachycephalic obstructive airway syndrome (BOAS) would show differences in left and right heart echocardiographic parameters compared with brachycephalic dogs without signs of BOAS and non-brachycephalic dogs. RESULTS: We included 57 brachycephalic (30 French Bulldogs 15 Pugs, and 12 Boston Terriers) and 10 non-brachycephalic control dogs. Brachycephalic dogs had significantly higher ratios of the left atrium to aorta and mitral early wave velocity to early diastolic septal annular velocity; smaller left ventricular (LV) diastolic internal diameter index; and lower tricuspid annular plane systolic excursion index, late diastolic annular velocity of the LV free wall, peak systolic septal annular velocity, late diastolic septal annular velocitiy, and right ventricular global strain than non-brachycephalic dogs. French Bulldogs with signs of BOAS had a smaller diameter of the left atrium index and right ventricular systolic area index; higher caudal vena cava at inspiration index; and lower caudal vena cava collapsibility index, late diastolic annular velocity of the LV free wall, and peak systolic annular velocity of the interventricular septum than non-brachycephalic dogs. CONCLUSIONS: The differences in echocardiographic parameters between brachycephalic and non-brachycephalic dogs, brachycephalic dogs with signs of BOAS and non-brachycephalic dogs, and brachycephalic dogs with and without signs of BOAS indicate higher right heart diastolic pressures affecting right heart function in brachycephalic dogs and those with signs of BOAS. Most changes in cardiac morphology and function can be attributed to anatomic changes in brachycephalic dogs alone and not to the symptomatic stage.

Wireless body sensor for electrocardiographic monitoring in dogs and cats.

OBJECTIVES: To evaluate the diagnostic utility of electrocardiogram data obtained by a wireless sensor from 36 dogs and four cats with suspected arrhythmias caused by cardiac or systemic diseases. MATERIALS AND METHODS: Wireless electrocardiographic recordings were obtained via two precordial electrodes attached to an electrocardiogram sensor connected to a smart device via low-power Bluetooth technology. Cardiac rate, rhythm and duration of P-QRS-T waves were evaluated with VisECG® software. Fifteen- to 30-minute wireless recordings were compared to standard electrocardiograms. Furthermore, the wireless sensor was used in 10 dogs and four cats for 24-hour continuous electrocardiogram monitoring at home. RESULTS: When compared to standard electrocardiogram, equivalent results were obtained for heart rate and duration of different waves. Due to the longer recording time, more arrhythmias were diagnosed with the wireless device in 50% (15 of 30) of animals with arrhythmias. Satisfactory recordings were obtained when the dogs were resting, standing or walking but interpretation of the wireless electrocardiogram signal was not possible during strenuous physical activity. CLINICAL SIGNIFICANCE: Wireless electrocardiographic monitoring is a reliable and accurate method for identification of heart rate, arrhythmia and duration of electrocardiogram waves. A higher diagnostic yield of arrhythmias was documented with the wireless sensor due to prolonged monitoring. The device offers a good option for the long-term monitoring of canine and feline cardiac rhythm.

Holter monitoring of small breed dogs with advanced myxomatous mitral valve disease with and without a history of syncope.

BACKGROUND: Syncope is a transient loss of consciousness occasionally occurring in dogs with advanced myxomatous mitral valve disease (MMVD). OBJECTIVE: (1) To study ECG changes during syncopal episodes in dogs with advanced MMVD and (2) to compare the occurrence of arrhythmias and changes in heart rate variability (HRV) between dogs with advanced MMVD with and without a history of syncope. ANIMALS: Forty-three privately owned dogs (<15 kg) with advanced MMVD: 21 with and 22 without a history of syncope. METHODS: Prospective study with dogs recruited for an evaluation including history, physical examination, echocardiography, and arrhythmia and HRV analysis performed on 24-hour Holter recordings. RESULTS: A syncopal episode was observed during Holter monitoring in 4 dogs: 3 dogs had sinus rhythm and 1 dog had sinus arrest followed by escape rhythm. An arrhythmia variable representing sinus arrhythmia was significantly lower in dogs with a history of syncope than in those without (P = .008). Eight of 26 HRV variables were significantly different between dogs with and without a history of syncope. CONCLUSIONS AND CLINICAL IMPORTANCE: Compared with dogs without a history of syncope, dogs with advanced MMVD and a history of syncope did not have a higher occurrence of arrhythmias, but had less sinus arrhythmia, and had changes in HRV variables representing decreased overall HRV, decreased parasympathetic, and increased sympathetic modulation of heart rate.

Advanced electrocardiographic parameters change with severity of mitral regurgitation in Cavalier King Charles Spaniels in sinus rhythm.

BACKGROUND: Multiple advanced resting ECG (A-ECG) techniques have improved the diagnostic or prognostic value of ECG in detecting human cardiac diseases even before onset of clinical signs or changes in conventional ECG. OBJECTIVE: To determine which A-ECG parameters, derived from 12-lead A-ECG recordings, change with severity of mitral regurgitation (MR) caused by myxomatous mitral valve disease (MMVD) in Cavalier King Charles Spaniels (CKCSs) in sinus rhythm. ANIMALS: Seventy-six privately owned CKCSs. METHODS: Dogs were prospectively divided into 5 groups according to the degree of MR (estimated by color Doppler mapping as the percentage of the left atrial area affected by the MR jet) and presence of clinical signs. High fidelity approximately 5-minute 12-lead ECG recordings were evaluated using custom software to calculate multiple conventional and A-ECG parameters. RESULTS: Nineteen of 76 ECG parameters were significantly different (P < .05) across the 5 dog groups. A 4-parameter model that incorporated results from 1 parameter of heart rate variability, 2 parameters of QT variability, and 1 parameter of QRS amplitude was identified that explained 82.4% of the variance with a correlation coefficient (R) of 0.60 (P < .01). When age or murmur grade was included in the statistical model the prediction value further increased the R to 0.74 and 0.85 (P < .01), respectively. CONCLUSION: In CKCSs with sinus rhythm, 4 selected A-ECG parameters further improve prediction of MR jet severity beyond age and murmur grade, although the predictive increment in this study probably is not sufficient to warrant utilization in clinical veterinary practice.