Ando' Giuseppe, Versaci Francesco
Department of Cardiac Surgery, Tor Vergata University of Rome, Italy.
BMC Cardiovasc Disord. 2005 Aug 9;5:23. doi: 10.1186/1471-2261-5-23.
Isolated, asymptomatic first degree AV block with narrow QRS has not prognostic significance and is not usually treated with pacemaker implantation. In some cases, yet, loss of AV synchrony because of a marked prolongation of the PR interval may cause important hemodynamic alterations, with subsequent symptoms of heart failure. Indeed, AV synchrony is crucial when atrial systole, the "atrial kick", contributes in a major way to left ventricular filling, as in case of reduced left ventricular compliance because of aging or concomitant structural heart disease.
We performed a trans-septal left atrium catheterization aimed at evaluating the entity of a mitral valve stenosis in a 72-year-old woman with a marked first-degree AV block, a known moderate aortic stenosis and NYHA class III symptoms of functional deterioration. We occurred in a deep alteration in cardiac hemodynamics consisting in an end-diastolic ventriculo-atrial gradient without any evidence of mitral stenosis. The patient had a substantial improvement in echocardiographic parameters and in her symptoms of heart failure after permanent pacemaker implantation with physiological AV delay.
We conclude that if a marked first degree AV block is associated to instrumental signs or symptoms of heart failure, the restoration of an optimal AV synchrony, achieved with dual-chamber pacing, may represent a reasonable therapeutic option leading to a consequent clinical improvement.
孤立的、无症状的一度房室传导阻滞伴窄QRS波无预后意义，通常不进行起搏器植入治疗。然而，在某些情况下，由于PR间期显著延长导致房室不同步，可能会引起重要的血流动力学改变，继而出现心力衰竭症状。实际上，当心房收缩（“心房辅助泵”）对左心室充盈起主要作用时，房室同步至关重要，比如在因衰老或合并结构性心脏病导致左心室顺应性降低的情况下。
我们对一名72岁女性进行了经房间隔左心房导管检查，旨在评估二尖瓣狭窄情况，该患者有明显的一度房室传导阻滞、已知的中度主动脉瓣狭窄以及纽约心脏病协会（NYHA）心功能Ⅲ级的功能恶化症状。我们发现心脏血流动力学出现严重改变，表现为舒张末期心室-心房压差，且无二尖瓣狭窄的任何证据。在植入具有生理性房室延迟的永久起搏器后，患者的超声心动图参数及心力衰竭症状有了显著改善。
我们得出结论，如果明显的一度房室传导阻滞与心力衰竭的器械检查体征或症状相关，通过双腔起搏实现最佳房室同步的恢复，可能是一种合理的治疗选择，会带来相应的临床改善。
