Laboratory of Comparative Cardiology, Department of Veterinary Medicine, Federal University of Paraná (UFPR), Curitiba, Brazil.
J Feline Med Surg. 2023 Feb;25(2):1098612X231151479. doi: 10.1177/1098612X231151479.
Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats. Electrocardiographic (ECG) analysis can help with the diagnosis of HCM and also in the investigation of the secondary consequences of the disease. This study investigated ECG markers of QT interval variability (total instability [TI], short-term instability [STI], long-term instability [LTI], QT variance [QTv]), mean QT interval (QTa) and QT interval corrected for heart rate (QTac), as well as the duration (QRSd) and dispersion (QRSv) of the QRS interval in healthy cats and in those with HCM.
Data were collected from 63 domestic cats: 40 in the control group and 23 in the HCM group. Fifty consecutive QT intervals were recorded for all cats and then QTa, QTac, QTv, TI, LTI and STI were calculated. QRSd and QRSv were also obtained for all animals. A Mann-Whitney U-test was used for group comparison. Receiver operating characteristic curves were plotted to evaluate the sensitivity and specificity of all markers for HCM. Logistic regression analysis was performed to assess the risks of cats having HCM, based on the studied indexes.
QTa ( <0.01), QTac ( <0.01), QRSd ( <0.01) and STI ( = 0.02) were higher in the HCM group. QTa >158.8 ms, QTac >27.4 ms and QRSd >0.045 s had an accuracy of 77.4%, 68.2% and 80.9%, respectively, in detecting HCM. Logistic regression showed that cats with QTa >158 ms, QTac >27.4 ms and QRSd >0.045 s had a 1.58-, 1,23- and 6.5-fold higher risk, respectively, of developing HCM.
Cats with HCM had higher ventricular instability as assessed by STI and showed a prolongation of the QT and QRS intervals via the QTa, QTac and QRSd markers. These markers show potential as ancillary screening tools for identifying the presence of HCM.
肥厚型心肌病（HCM）是猫最常见的心脏病。心电图（ECG）分析有助于 HCM 的诊断，也有助于研究疾病的继发性后果。本研究调查了 QT 间期变异性的心电图标志物（总不稳定性[TI]、短期不稳定性[STI]、长期不稳定性[LTI]、QT 方差[QTv]）、平均 QT 间期（QTa）和心率校正的 QT 间期（QTac），以及健康猫和 HCM 猫的 QRS 间期的持续时间（QRSd）和离散度（QRSv）。
从 63 只家猫中收集数据：对照组 40 只，HCM 组 23 只。所有猫均记录连续 50 个 QT 间期，然后计算 QTa、QTac、QTv、TI、LTI 和 STI。所有动物均获得 QRSd 和 QRSv。采用 Mann-Whitney U 检验进行组间比较。绘制受试者工作特征曲线，评估所有标志物对 HCM 的敏感性和特异性。基于研究指标，进行逻辑回归分析，评估猫患 HCM 的风险。
HCM 组的 QTa（<0.01）、QTac（<0.01）、QRSd（<0.01）和 STI（=0.02）均较高。QTa>158.8 ms、QTac>27.4 ms 和 QRSd>0.045 s 对 HCM 的检出率分别为 77.4%、68.2%和 80.9%。逻辑回归显示，QTa>158 ms、QTac>27.4 ms 和 QRSd>0.045 s 的猫患 HCM 的风险分别增加 1.58 倍、1 倍和 6.5 倍。
HCM 猫的 STI 评估心室不稳定性较高，通过 QTa、QTac 和 QRSd 标志物显示 QT 和 QRS 间期延长。这些标志物可能作为辅助筛选工具，用于识别 HCM 的存在。
