Fragakis Nikolaos, Iliadis Ilias, Sidopoulos Emmanouil, Lambrou Alexandra, Tsaritsaniotis Evangelos, Katsaris George
2nd Cardiac Department, Kromnis 42, 55131 Thessaloniki, Greece.
Europace. 2007 Aug;9(8):559-62. doi: 10.1093/europace/eum099. Epub 2007 Jul 19.
Patients (pts) with sick sinus syndrome (SSS) and unexplained syncope show increased susceptibility of sinus and atrioventricular node (AVN) to intravenous adenosine, respectively. Our aim is to assess the diagnostic value of adenosine test in pts with SSS, as well as to evaluate the response of AVN to adenosine either in pts with unexplained syncope or in pts with syncope and known SSS.
The effect of adenosine administration on the sinus and AVN was studied in a population consisted of 19 pts with clinical SSS (group SSS), 7 pts with syncope of unknown origin (group SUO), and 12 control subjects (group C). We calculated the maximum corrected sinus node recovery time (CSNRT), after overdrive pacing of the atrium at cycle lengths of 600, 500, and 400 ms and compared this value with the longest sinus pause, following adenosine administration corrected to the basic cycle length (ADSNRT). The longest R-R interval during atrioventricular block in response to adenosine injection (ADAVB) was also measured. Adenosine was given in a bolus dose of 0.15 mgr/kg through a femoral or large antecubital vein. There was a significant difference in the mean values of CSNRT among the three groups: group SSS (651 +/- 228 ms) > group SUO (284 +/- 100 ms) = group C (291 +/- 117 ms), F(2.35) = 19.078, P = 0.000. A significant difference was also found with ADSNRT: group SSS (5437 +/- 6863 ms) > group SUO (122 +/- 120 ms) = group C (801 +/- 1897 ms), F(2.35) = 4.513, P = 0.018. Using 525 ms as a cutoff value indicating sinus node dysfunction, CSNRT had a sensitivity of 74% and specificity of 100% for diagnosis of SSS while ADSNRT had 94% and 84%, respectively. Higher values of ADAVB in pts with SSS (10659 +/- 5872) and SUO (10026 +/- 7092) in comparison with controls (3615 +/- 5002) were measured, F(2.35) = 5.697, P = 0.007. No difference in the degree of ADAVB was found between the pts with SUO (10026 +/- 7092 ms) and syncope in the presence of SSS (12058 +/- 6787 ms), F(1.15) = 0.356, P = 0.56.
Adenosine test appears to be at least comparable with CSNRT in making the diagnosis of SSS and may be considered as an alternative non-invasive test for confirmation of suspected SSS. No difference in the susceptibility of AVN to adenosine between the pts with syncope in the presence of SSS and those with unexplained syncope was found, suggesting that adenosine test cannot be used to diagnose atrioventricular block as the cause of syncope.
病态窦房结综合征（SSS）患者和不明原因晕厥患者的窦房结和房室结（AVN）对静脉注射腺苷的敏感性分别增加。我们的目的是评估腺苷试验对SSS患者的诊断价值，并评估不明原因晕厥患者或已知SSS合并晕厥患者的房室结对腺苷的反应。
在由19例临床SSS患者（SSS组）、7例不明原因晕厥患者（SUO组）和12例对照者（C组）组成的人群中研究了腺苷给药对窦房结和房室结的影响。我们计算了在600、500和400毫秒的周期长度下对心房进行超速起搏后的最大校正窦房结恢复时间（CSNRT），并将该值与腺苷给药后校正至基础周期长度的最长窦性停搏（ADSNRT）进行比较。还测量了静脉注射腺苷后房室传导阻滞期间的最长R-R间期（ADAVB）。通过股静脉或大肘前静脉以0.15毫克/千克的推注剂量给予腺苷。三组之间CSNRT的平均值存在显著差异：SSS组（651±228毫秒）>SUO组（284±100毫秒）=C组（291±117毫秒），F(2.35)=19.078，P=0.000。ADSNRT也存在显著差异：SSS组（5437±6863毫秒）>SUO组（122±120毫秒）=C组（801±1897毫秒），F(2.35)=4.513，P=0.018。以525毫秒作为提示窦房结功能障碍的临界值，CSNRT诊断SSS的敏感性为74%，特异性为100%，而ADSNRT的敏感性和特异性分别为94%和84%。测量发现，与对照组（3615±5002）相比，SSS患者（10659±5872）和SUO患者（10026±7092）的ADAVB值更高，F(2.35)=5.697，P=0.007。在SUO患者（10026±7092毫秒）和存在SSS的晕厥患者（12058±6787毫秒）之间未发现ADAVB程度的差异，F(1.15)=0.356，P=0.56。
腺苷试验在诊断SSS方面似乎至少与CSNRT相当，可被视为用于确诊疑似SSS的一种替代性非侵入性检查。在存在SSS的晕厥患者和不明原因晕厥患者之间，未发现房室结对腺苷的敏感性存在差异，这表明腺苷试验不能用于诊断房室传导阻滞是晕厥的原因。
