Orthodromic Atrioventricular Reciprocating Tachycardia in a Dalmatian

• 作者: Marlos G. Sousa Roberta Carareto Stephany B. Lucina
• 来源期刊: 兽医学(英文)
• 学科: 医学
• 关键词: ARRHYTHMIA TACHYCARDIOMYOPATHY ACCESSORY PATHWAY REENTRANT ARRHYTHMIA
• 年，卷（期）: syxyw_2018,（1）
• 页码范围: 1-8
• 页数: 8页
• 分类号: R5

摘要

Supraventricular tachyarrhythmias may be caused by macroreentry circuits involving the AV node and accessory pathways. This paper reports a case of suspected orthodromic atrioventricular reciprocating tachycardia in an 18-month-old Dalmatian admitted with dyspnea and a lifelong history of fatigue. Cardiac auscultation documented a regular fast pace with no heart murmurs. The electrocardiogram characteristics were consistent with supraventricular tachycardia, with very regular RR interval and narrow QRS complexes. At lead II, we identified negative P waves buried within the ST segment, which resulted in a RP-to-PR ratio of 0.60, but in aVR these P waves were positive, suggesting a retrograde conduction of electrical impulses throughout the atrial myocardium. The echocardiographic study showed volume overload, and a decreased fractional shortening was calculated when SVT was sustained, highlighting its impact on systolic function. This is likely the first description of an orthodromic atrioventricular reciprocating tachycardia in a Dalmatian, and although cardiac mapping was not available to confirm this suspicion, all electrocardiograpic features were supportive of such arrhythmia.