Abstract：
OBJECTIVE: Borzoi reportedly experience sudden death. The objective of this study was to report ECG intervals, amplitudes, and frequency of ECG abnormalities in clinically healthy Borzoi.
METHODS: 98 clinically healthy Borzoi were prospectively recruited and underwent echocardiogram, ECG, and cardiac troponin I testing between October 2020 and December 2022. Standard ECG measurements were obtained. Early repolarization notches and slurs were recorded.
RESULTS: Of 82 Borzoi with a structurally normal echocardiogram, ventricular arrhythmias were documented in 8 (10%) dogs, all of which had normal cardiac troponin I concentrations. Median P wave duration was 55 milliseconds (range, 45 to 70 milliseconds). Median PR interval was 125 milliseconds (range, 80 to 175 milliseconds). Thirty-one (38%) Borzoi had first-degree atrioventricular block (PR interval > 130 milliseconds). Median QRS duration was 65 milliseconds (range, 48 to 90 milliseconds). Median QT interval was 235 milliseconds (range, 185 to 275 milliseconds). Twenty-nine (35%) and 15 (18%) of 82 Borzoi had QT intervals > 240 or > 250 milliseconds, respectively. Sixty-seven of 82 (82%) Borzoi had early repolarization notches or slurs. Seventeen of 82 (21%) Borzoi had an abnormality of the ST segment, most commonly convexity/doming. Convexity of the ST segment was intermittent (n = 9) or persistent (4).
CONCLUSIONS: Ventricular arrhythmias, early repolarization, prolonged QT intervals, and ST segment abnormalities are not infrequent in clinically healthy Borzoi. P, PR, and QRS durations are commonly prolonged compared to general canine reference intervals.
CONCLUSIONS: Future study into heritable channelopathies in Borzoi is warranted given the frequency of ventricular arrhythmias, repolarization abnormalities, and sudden death in the breed. Breed-specific ECG reference intervals are needed.
METHODS: 98 clinically healthy Borzoi were prospectively recruited and underwent echocardiogram, ECG, and cardiac troponin I testing between October 2020 and December 2022. Standard ECG measurements were obtained. Early repolarization notches and slurs were recorded.
RESULTS: Of 82 Borzoi with a structurally normal echocardiogram, ventricular arrhythmias were documented in 8 (10%) dogs, all of which had normal cardiac troponin I concentrations. Median P wave duration was 55 milliseconds (range, 45 to 70 milliseconds). Median PR interval was 125 milliseconds (range, 80 to 175 milliseconds). Thirty-one (38%) Borzoi had first-degree atrioventricular block (PR interval > 130 milliseconds). Median QRS duration was 65 milliseconds (range, 48 to 90 milliseconds). Median QT interval was 235 milliseconds (range, 185 to 275 milliseconds). Twenty-nine (35%) and 15 (18%) of 82 Borzoi had QT intervals > 240 or > 250 milliseconds, respectively. Sixty-seven of 82 (82%) Borzoi had early repolarization notches or slurs. Seventeen of 82 (21%) Borzoi had an abnormality of the ST segment, most commonly convexity/doming. Convexity of the ST segment was intermittent (n = 9) or persistent (4).
CONCLUSIONS: Ventricular arrhythmias, early repolarization, prolonged QT intervals, and ST segment abnormalities are not infrequent in clinically healthy Borzoi. P, PR, and QRS durations are commonly prolonged compared to general canine reference intervals.
CONCLUSIONS: Future study into heritable channelopathies in Borzoi is warranted given the frequency of ventricular arrhythmias, repolarization abnormalities, and sudden death in the breed. Breed-specific ECG reference intervals are needed.
摘要：
目的：据报道，Borzoi经历了猝死。这项研究的目的是报告心电图间隔，振幅，临床健康的Borzoi的心电图异常频率。
方法：前瞻性招募了98名临床健康的Borzoi，并进行了超声心动图检查，心电图,和心脏肌钙蛋白I在2020年10月至2022年12月之间进行测试。获得标准ECG测量值。记录了早期的复极化凹口和污点。
结果：在82只具有结构正常超声心动图的Borzoi中，记录了8只（10％）狗的室性心律失常，所有这些都有正常的心肌肌钙蛋白I浓度。中值P波持续时间为55毫秒（范围，45到70毫秒)。中位PR间隔为125毫秒(范围，80到175毫秒)。31例（38％）Borzoi患有一级房室传导阻滞（PR间期>130毫秒）。QRS持续时间中位数为65毫秒（范围，48到90毫秒)。中值QT间期为235毫秒(范围，185到275毫秒）。82只Borzoi中有29只（35％）和15只（18％）的QT间隔>240或>250毫秒，分别。82只（82％）的Borzoi中有67只具有早期的复极化凹口或污点。82只Borzoi中有17只（21％）有ST段异常，最常见的是凸性/隆起。ST段的凸度是间歇性的（n=9）或持续性的（4）。
结论：室性心律失常，早期复极化，QT间期延长，并且ST段异常在临床健康的Borzoi中并不少见。P,PR,与一般犬参考间隔相比，QRS持续时间通常延长。
结论：考虑到室性心律失常的发生频率，有必要对Borzoi的遗传性信道病进行未来研究，复极异常,和突然死亡的品种。需要品种特异性ECG参考间隔。
方法：前瞻性招募了98名临床健康的Borzoi，并进行了超声心动图检查，心电图,和心脏肌钙蛋白I在2020年10月至2022年12月之间进行测试。获得标准ECG测量值。记录了早期的复极化凹口和污点。
结果：在82只具有结构正常超声心动图的Borzoi中，记录了8只（10％）狗的室性心律失常，所有这些都有正常的心肌肌钙蛋白I浓度。中值P波持续时间为55毫秒（范围，45到70毫秒)。中位PR间隔为125毫秒(范围，80到175毫秒)。31例（38％）Borzoi患有一级房室传导阻滞（PR间期>130毫秒）。QRS持续时间中位数为65毫秒（范围，48到90毫秒)。中值QT间期为235毫秒(范围，185到275毫秒）。82只Borzoi中有29只（35％）和15只（18％）的QT间隔>240或>250毫秒，分别。82只（82％）的Borzoi中有67只具有早期的复极化凹口或污点。82只Borzoi中有17只（21％）有ST段异常，最常见的是凸性/隆起。ST段的凸度是间歇性的（n=9）或持续性的（4）。
结论：室性心律失常，早期复极化，QT间期延长，并且ST段异常在临床健康的Borzoi中并不少见。P,PR,与一般犬参考间隔相比，QRS持续时间通常延长。
结论：考虑到室性心律失常的发生频率，有必要对Borzoi的遗传性信道病进行未来研究，复极异常,和突然死亡的品种。需要品种特异性ECG参考间隔。
