Tpeak-Tend, a novel electrocardiographic marker in cats with hypertrophic cardiomyopathy-a brief communication.

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in feline species. ECG allows assessing parameters that can help in the diagnosis and risk stratification of conditions that occur secondary to this disease. This study aimed to evaluate electrocardiographic markers Tpte and Tpte/QT in leads I, II, III, aVR, aVL and aVF in control and HCM cats. Data were obtained from 63 domestic cats allocated in a Control (n = 40) and an HCM (n = 23) group. Tpte and Tpte/QT of all individuals were measured in all limb leads (I, II, III, aVR, aVL, aVF). We constructed ROC curves to evaluate the sensitivity and specificity of markers to identify HCM-affected cats. Logistic regression analysis was performed to assess the risks of cats having HCM based on Tpte indexes. Tpte in leads II (p < 0.01), aVR (p < 0.01), aVL (p < 0.01), and aVF (p < 0.01) had significantly higher results in the HCM group. Tpte/QT showed no statistical difference between groups in any of the derivations evaluated. A Tpte > 27.5ms in lead aVF showed an accuracy of 83.3% to identify individuals with HCM in our study. Univariable logistic regression reveals that cats with Tpte in aVR and aVF > 27.5ms and in aVL > 26.5ms had 1.28, 12 and 1.16 respectively, more chances of having HCM. The prolongation of Tpte may be a noninvasive electrocardiographic complementary tool to help differentiate patients with and without hypertrophic cardiomyopathy.

Tissue motion annular displacement to assess the left ventricular systolic function in healthy cats.

The tissue motion annular displacement (TMAD) measures the longitudinal displacement of the mitral annulus during systole, using speckle-tracking echocardiography (STE). The main objective was to determine the TMAD means in healthy cats, exploring the correlations with systolic surrogates. The influence of age, body surface area (BSA), heart rate, and systemic blood pressure on the indices was also analyzed. One hundred ninety-three healthy, client-owned cats participated in this prospective, cross-sectional observational study undergoing conventional and STE. Apical four-chamber (AP4) and two-chamber (AP2) images were recorded for offline calculations. Mean TMAD values were similar to mitral annulus plane systolic excursion (MAPSE), varying between 4 to 4.8 mm depending on the annulus and image used. No significant differences between age and BSA categories were detected, except for AP4 MP%, reduced in the heavier group. TMAD variables showed moderate correlation with longitudinal strain (LSt) and MAPSE, but not with fraction shortening (FS) and ejection fraction (EF). The median time required for the offline calculation was 12.2 s for AP4 and 11.8 s for AP2. The technique showed moderate inter and intraobserver variation, proving a reliable tool for assessing left ventricular longitudinal systolic function in cats.

Polymorphism, coupling interval and prematurity index in dogs with degenerative mitral valve disease and ventricular arrhythmias.

Ventricular arrhythmias (VA) are a recognized concern in dogs with degenerative mitral valve disease (DMVD). The coupling interval (CI) and the prematurity index (PI) have been shown to accurately differentiate between benign and malignant VA in people, where ventricular arrhythmias are known to be associated with an increased risk of development of signs of heart failure or sudden death. In this study, we characterized ventricular arrhythmias in dogs with symptomatic and asymptomatic DMVD. Seventy dogs with naturally-occurring DMVD and ventricular arrhythmias were retrospectively studied. A cross-sectional investigation including dogs with either symptomatic (stages C/D; n = 41) or asymptomatic (stages B1/B2; n = 29) DMVD was performed. Electrocardiographic tracings were reviewed to calculate both the CI and PI. In eight dogs these indices were compared with those obtained from both a Holter recording and a standard ECG tracing and no statistical differences were found (CI, p = 0.97; PI, p = 0.17). Even though CI and PI were determined in all animals enrolled in the study, VPC characteristics were only compared between symptomatic and asymptomatic dogs when a 24-h Holter recording was available (n = 49). The PI was different (p = 0.01) between symptomatic (0.65 ± 0.17) and asymptomatic (0.56 ± 0.18) dogs, but CI was considered similar (p = 0.91). Also, the symptomatic dogs had more polymorphic VPC (p = 0.002) and supraventricular arrhythmias (p = 0.0002) than the asymptomatic animals. Polymorphism, and repeating patterns of ventricular premature complexes, were characteristics frequently present in overtly symptomatic animals affected by mitral endocardiosis.