Characteristics and outcomes of cats with and without pacemaker placement for high-grade atrioventricular block

Available information on characteristics and outcome in cats with high-grade atrioventricular block (AVB) that receive a pacemaker is limited. Twenty-two privately owned cats presenting with high-grade AVB. Medical records were retrospectively examined. Cats were grouped as having received a pacemaker (PACE group) or not having received a pacemaker (non-PACE group). Clinical characteristics and outcomes of groups were evaluated. There were 10 cats in the PACE group and 12 cats in the non-PACE group. At presentation, syncope or seizure-like behavior (p = 0.004) and bradycardia (p = 0.043) were more common in the PACE than the non-PACE group. Historical lethargy (p = 0.015) and dull mentation (p = 0.045) were more common in the non-PACE group, as was clinically relevant systemic disease. Pacemaker placement improved syncope or seizure-like behavior in 100% of cats. The degree of AVB at presentation was not associated with pacemaker placement nor the future degree of AVB. The major complication rate of pacemaker placement was 40%. Intergroup survival was not significantly different (PACE group 1278 days, 95% confidence interval: 0–2145 days; non-PACE group 213 days, confidence interval: 1–not available, p = 0.77). Pacemaker placement improved clinical signs in cats with high-grade AVB. A difference in survival time could not be demonstrated between cats that received and did not receive a pacemaker in this retrospective study. High-grade AVB can be transient and accompanied by systemic disease in some cats.