Long-term management of high-grade atrioventricular block using cilostazol in a cat

Abstract

Case summary A 12-year-old neutered female domestic shorthair cat was admitted for syncope. Clinical signs and electrocardiography revealed high-grade atrioventricular (AV) block. Treatment with cilostazol ameliorated the clinical signs and arrhythmia. However, the high-grade AV block recurred on several occasions. After 640 days, the cat presented again with clinical deterioration owing to reoccurrence of the arrhythmia and it died 11 days later. Histopathological examination revealed a loss of conduction cells within the His bundle. Relevance and novel information To our knowledge, this is the first report of high-grade AV block treated with cilostazol in a cat. Treatment with cilostazol prolonged survival for 650 days without pacemaker implantation. Histological findings suggested that the AV block was related to fibrosis of the impulse conduction system.

Paroxysmal atrioventricular block in a mixed‐breed dog

“…described that the branching portion of the AV bundle was less severely affected by fibrosis in cats diagnosed with PAV than in those with third‐degree AV block. Since the dog in this case report was an older dog, it is possible that the findings would be similar to those described in older cats 18,20 …”

“…Since the dog in this case report was an older dog, it is possible that the findings would be similar to those described in older cats. 18,20 The fact that a 24-h Holter analysis was not performed is an important limitation of this report. A further limitation is the sudden unexpected death of the dog, which prevented gathering of further information about the baseline cardiac rhythm and efficacy of medical therapy or indications for pacing.…”

“…The aetiology of PAVB in cats is still unknown, but correlations between structural cardiac diseases and systemic disorders such as hyperthyroidism and PAVB have been described. 2,16,17 Some authors have hypothesised that acute myocarditis might also be involved in the genesis of PAVB, 9 and there are descriptions of AV conduction system fibrosis in affected cats, 18,19 similar to that described in older people. 11 Recently, Machida et al described that the branching portion of the AV bundle was less severely affected by fibrosis in cats diagnosed with PAV than in those with third-degree AV block.…”

Comparison of the cardiovascular effects of immobilization with three different drug combinations in free-ranging African lions

“…Furthermore, organs that have a rich arteriolar supply, like the eyes, brain, kidneys and myocardium, are particularly vulnerable to injury caused by the mechanical damage from high pressures ( Taylor et al, 2017 ). Although conscious individuals with first- or second-degree AV blocks usually show no clinical signs ( Iwasa et al, 2019 ), the consequences of these during immobilization, especially when perfusion is already low, is also a potential clinical concern. Therefore, the consequence of the skipped heart beats observed in the immobilized lions should be determined.…”