St Luke's University Health Network, Warren Campus, 185 Roseberry Street, Phillipsburg, NJ, 08865, USA.
BMC Infect Dis. 2019 May 16;19(1):428. doi: 10.1186/s12879-019-4025-0.
Lyme disease (LD), is the most common vector-borne illness in the US and Europe, with predominantly cutaneous, articular, cardiac and neuro-psychiatric manifestations. LD affects all layers of the heart and every part of the conducting system. Carditis is a less common manifestation of LD. Heart block (HB) as the initial and sole manifestation of LD is rare. Inducible HB has never been reported in LD. We report a case of heart block (HB) inducible with exercise and reversible with rest.
A 37-year-old male presented to the emergency department after experiencing two episodes of syncope while at work. He presented, with a heart rate of 57 bpm, and the ECG showed sinus bradycardia with first degree AV block. The PR interval was 480 ms (NL 120-200 ms). Physical exam was unremarkable. The cardiologist's initial impression was vaso-vagal attack. He developed high degree AV block during a stress test for the initial work up, which resolved on cessation of exercise. A similar episode while walking in the hallway, resolved at rest. The high degree AV block appeared inducible with exercise and reversible with rest. His Lyme serology was strongly positive. He was treated with ceftriaxone and doxycycline. After completing treatment, the patient had a normal ECG and returned to work without limitations, doing manual labor.
Manifestations of Lyme carditis (LC) vary from asymptomatic and symptomatic electrocardiographic changes and heart block (HB) reversible with treatment, to sudden death. HB as the sole and initial presentation of LC is rare. There have been no reports of inducible HB in LD. Here we present a case of inducible and reversible high degree HB in a case of LC and an update of literature. Exercise and stress testing should be avoided in suspected cases of LC until resolution of carditis. Lyme carditis should be suspected in individuals with cardiac manifestations in an endemic area, particularly in the younger patients with no other etiology evident.
莱姆病（LD）是美国和欧洲最常见的虫媒病，主要表现为皮肤、关节、心脏和神经精神疾病。LD 影响心脏的所有层和传导系统的每个部分。心炎是 LD 的一种较不常见的表现。HB 作为 LD 的初始和唯一表现较为少见。LD 从未报道过可诱导 HB。我们报告了一例可诱导运动的 HB，并可通过休息逆转。
一名 37 岁男性在工作时经历了两次晕厥发作后到急诊就诊。他的心率为 57bpm，心电图显示窦性心动过缓伴一度房室传导阻滞。PR 间期为 480ms（NL 120-200ms）。体格检查无明显异常。心脏病专家的初步印象是血管迷走神经性发作。他在进行初始工作的应激测试时出现高度房室传导阻滞，停止运动后缓解。在走廊散步时出现类似的发作，在休息时缓解。高度房室传导阻滞可通过运动诱导，通过休息可逆转。他的莱姆血清学检查呈强阳性。他接受了头孢曲松和多西环素治疗。在完成治疗后，患者心电图正常，返回工作岗位，无任何限制，从事体力劳动。
莱姆心脏炎（LC）的表现从无症状和有症状的心电图改变和可治疗的 HB 到猝死不等。HB 作为 LC 的唯一和初始表现较为少见。LD 中没有关于可诱导 HB 的报道。在此，我们报告了一例 LC 中可诱导和可逆转的高度 HB 病例，并更新了文献。在疑似 LC 病例中，应避免运动和应激测试，直至心炎消退。在流行地区，特别是在无其他明显病因的年轻患者中，有心脏表现的患者应怀疑莱姆心脏炎。
