心脏起搏对心脏泵血功能的影响

本文对32例接受永久性心脏起搏器治疗患者进行了血液动力学研究。在PR间期于100～200ms的生理范围内,非同步心室收缩(心室心律,心室起搏)的心输出量较之房室同步收缩(正常窦性心律、心房起搏及房室同步起搏)的心输出量低14～17%。生理性起搏能提高心输出量,因其保留心房泵血机制,这对心脏病患者是重要的。70次/分的起搏可以满足静息状态下的生理需要,太快的起搏对患者无血液动力学益处。     

心脏瓣膜替换术122例分析

本院自１９８４年３月至１９９２年１２月，应用侧倾碟瓣、牛心包生物瓣和Ｓｔ．Ｊｕｄｅ瓣施行心脏瓣膜替换１２２例。除１例外，病因均为风湿性病变。二尖瓣替换９６例，双瓣膜替换１７例，主动脉瓣替换９例。心功能（ＮＹＨＡ）Ⅲ级者７８例，Ⅳ级者２１例。术后１个月内死亡１５例（１２．３％）。死亡原因主要为心室颤动，细菌性、霉菌性心内膜炎，低心输出量综合征等。８３例随访６～９６个月，晚期死亡５例。余均症状改善，多数已恢复工作。本文还就换瓣手术指征，心室颤动的原因，重症患者机械呼吸的应用，术后心内膜炎等问题进行讨论。     

术中经食管超声技术在心脏外科中的应用

本文利用经食管超声心动图（ＴＥＥ）技术观察了３５例心脏病患者在手术前后的心内结构变化及血流信息。结果表明，术中ＴＥＥ不干扰手术视野，且使心内结构显像更加清晰，可证实术前诊断及评价即刻手术效果，故可为心外科医生选择或修正手术方法提供更多的信息。     

INVESTIGATION OF THE CRITERIA FOR ASSESSING THE OUTCOME OF TREATMENT IN ACROMEGALY

The outcome of treatment in acromegaly is usually assessed by measuring plasma concentrations of growth hormone (GH)--either basal spontaneous levels or during hyperglycaemia. There is no consensus on how cure should be defined. Many studies have considered basal plasma growth hormone concentrations below 20 mU/l (10 ng/ml) as proof of cure, although some recent studies have applied lower values. At present a limit of 10 mU/l (5 ng/ml) seems to be accepted as evidence of cure. We have studied 28 acromegalic patients after transsphenoidal adenomectomy. Plasma GH concentrations (basal and during hyperglycaemia) as well as plasma somatomedin C (SMC) concentrations were measured and compared to the clinical symptoms. There was a close correlation between plasma GH and SMC concentrations (except when plasma GH levels were low) and between the clinical assessment and SMC concentrations. Very low plasma GH levels (less than 1 mU/l or 0.5 ng/ml) were associated with normal SMC values and clinical cure, high GH levels (greater than 10 mU/l or 5 ng/ml) with elevated SMC levels and persisting acromegaly. Moderately elevated plasma GH concentrations (1.9-9.6 mU/l) did not allow any conclusions on the outcome of treatment as assessed from SMC determinations and clinical evaluation. It is concluded that the usual criteria for cure in acromegaly may not be sufficiently strict.     

ROLE OF THE SYMPATHETIC NERVOUS SYSTEM IN CARDIAC REMODELING IN HYPERTENSION

The role of the sympathetic nervous system in the settings of cardiac hypertrophy is postulated on the basis of experimental and clinical evidence. Only recently, the intimate mechanisms underlying hypertrophic responses of cardiac cell have been explored. Recent evidence spots the role of adrenergic receptors in the activation of several intracellular pathways of signaling that lead to nuclear responses of myocardiocyte.

The molecular structures involved in these pathways may represent novel targets of future therapeutic interventions for cardiac hypertrophy and vascular remodeling in hypertension.