Preservation of pre-excitation despite acute myocardial infarction complicated by complete heart block.

In a 53-year-old man with ventricular pre-excitation (normal PR interval, QRS interval of 0.12 seconds and delta-waves) acute inferior wall myocardial infarction was complicated by, successively, first-degree atrioventricular block, second-degree atrioventricular block (Wenckebach type) and complete heart block. The QRS pattern of pre-excitation was preserved throughout these events. The classification of ventricular pre-excitation is reviewed and the correlation between the various electrocardiographic patterns (the Wolff-Parkinson-White syndrome and its variants and the Lown-Ganong-Levine syndrome) and the anomalous conduction pathways of Kent, James and Mahaim are discussed. In this case the best possible explanation for preservation of pre-excitation during complete heart block was the existence of accessory fibres of Mahaim.     

Nonsurgically-acquired complete atrioventricular block in endocardial cushion defect

Complete atrioventricular heart block (CAVB) most commonly occurs as a complication of cardiac surgery. We report the development of CAVB in an 8-year-old girl with endocardial cushion defect (ECD) who had not undergone a cardiac operation. Although this is the first report of acquired non-surgical CAVB in a child with ECD, we believe that the development of CAVB in patients with unoperated ECD occurs more commonly than is usually realized. An increased awareness of this possibility will allow expedient diagnosis, which is essential to proper treatment. In most cases, the implantation of a permanent ventricular pacemaker will alleviate congestive heart failure or prevent sudden death.     

An unusual case of complete atrioventricular block causing Takotsubo syndrome

Complete atrioventricular (AV) block in association with Takotsubo syndrome (TS) has been well recognized, but the cause and effect relationship has not been elucidated. We describe a 78-year-old female who presented with complete AV block but one week later developed new-onset, diffuse T-wave inversions, QT prolongation, and acceleration of junctional escape rate. Left ventriculogram revealed features typical of TS. One year after permanent pacemaker implantation, complete AV block persisted despite the reversal of wall motion defects implying that conduction abnormality was the trigger of TS rather than its consequence.     

Mechanically induced complete atrioventricular block during retrograde catheter ablation of a left-sided incessant tachycardia

Concern for potentially lethal complications related to transseptal catheterisation, such as perforation of the aorta, has made this approach less attractive over the last decades. Nevertheless, this method is now increasingly being used for ablation of left-sided arrhythmias. We report a transient complication of a retrograde procedure in a patient with a left-sided ''Coumel-type'' incessant tachycardia. We had to proceed to transseptal catheterisation, as the complication recurred during the second attempt even when using a less rigid transaortic radiofrequency catheter. The transseptal approach using a less stiff cryoenergy catheter was performed without complications.     

Clinical aspects of acute coronary syndromes

There are two types of acute coronary syndromes : those with or without ST-segment elevation. The former require urgent therapeutic measures to reopen the culprit artery (intravenous thrombolysis or primary percutaneous coronary intervention). For the latter, risk stratification is essential and is based upon clinical and biochemical markers. Among them, recent and repeated anginal attacks, ST-segment modifications on admission electrocardiogram, and increased markers of myonecrosis (particularly increased troponin levels) are strong predictors of untoward outcome. According to the risk profile, the initial management is based upon an invasive strategy with powerful antithrombotic medications and urgent angiography, or upon a non-invasive strategy using stress testing, preferably coupled with myocardial imaging techniques. In all instances, secondary prevention measures are determinant to try and stop the progression of the atherosclerotic disease.     

急性一氧化碳中毒致心肌损害临床研究

目的研究急性一氧化碳（CO）中毒对心脏的损害。方法选择急诊入院的急性CO中毒患者102例,分为轻度、中度和重度中毒组,同时在健康体检人群中随机选择100例健康人为对照组。中毒组的病例入院24h采静脉血测定心肌酶及行心电图检查;对照组清晨抽空腹静脉血．测定心肌酶并完成12导联心电图描记。结果急性CO中毒患者中有63例血清心肌酶谱改变,占61.77％。中、重度中毒者多有不同程度的心肌酶升高,与健康对照组相比,差异有统计学意义（P〈0．01）;重、中度中毒组相比。差异亦有统计学意义（P〈0．01）。心电图异常改变有70例．占68．63％。经治疗,除2例病重无康复外．其余100例均康复出院．在CO中毒纠正后心肌酶和心电图均恢复正常。蛄论急性CO中毒不仅对神经系统造成损害．对心脏的损害也较严重,需要给予相应的治疗.