Analysis of perioperative ventricular arrhythmias in valvular heart diseases by Holter ECG recording.

Seventy-one consecutive patients undergoing cardiac surgery for acquired valvular diseases were analyzed to determine the incidence of and the predisposing factors to postoperative ventricular arrhythmias. We recorded the Holter ECGs before (pre-op), and within 24h (op-day) and 4 to 10 weeks after operation (post-op) and determined the frequency of ventricular arrhythmias and the degree according to the Lown grade. The relationship between the op-day ventricular arrhythmias and clinical, hemodynamic, operative or postoperative variables was examined. The operation included mitral valve replacement or open mitral commissurotomy (49 patients, group M), aortic valve replacement (12 patients, group A) and a combined mitral and aortic operation (10 patients, group A + M). In all groups, the frequency and the degree of ventricular arrhythmias increased at the op-day and decreased at the post-op period approximately to the pre-op level. The frequency and Lown grade of the 3 groups were similar in each of the pre-op, the op-day and the post-op periods. The frequency and Lown grade of the op-day ventricular arrhythmias increased with increases in the arrhythmia frequency and Lown grade at the pre-op period, and in patients with left ventricular (LV) dysfunction at the post-op period, as evidence by an increased LV volume and decreased ejection fraction on echocardiograms. Furthermore, the frequency of ventricular premature contractions in the op-day was significantly less when a cardioplegia solution containing magnesium was used than in the case of a cardioplegia solution without magnesium. The op-day ventricular arrhythmias showed no significant relation to extracorporeal circulation time, aortic cross-clamping time, the antiarrhythmic drugs used and the op-day serum levels of K and CK-MB.     

100 years' of ECG or 100 years' of excellence in recording the electrical activity of the human heart

The authors present a brief history of high-standard records of the electric activity of the human heart. Its beginnings date back to 1892 when Willem Einthoven recorded the first electrocardiogram.     

健康人异常心电图的分析

目的：探讨健康人异常心电图的预后意义。方法：于2002年5月至2004年5月对福州地区56863例健康人进行了心电图检查。结果：56863例体检者中心电图异常率依次为：ST段下移1396例（2.455％）。左前分支传导阻滞906例（1.593％）。室性期前收缩682例（1.199％），完全性右束支传导阻滞676例（1.189％），Ⅰ度房室传导阻滞303例（0.533％），心房颤动102例（0.179％），室上性心动过速21例（0.037％），Ⅱ度房室传导阻滞19例（0.033％），窦房传导阻滞14例（0.025％），左束支传导阻滞6例（0.011％）。左后分支传导阻滞6例（0.011％），心房扑动4例（0.007％）。结论：健康人心电图检查发现的心电图异常有助于心脏病的早期发现和防治。     

The clinical value of Holter ECG recording

The Holter ECG is a well established clinical tool to document intermittent arrhythmias. The main indications are palpitations and syncope. However, the occurrence of these events during 24 h recording is very rare. So, it is often a matter of definition, what findings can speculatively "explain" a syncope. Therefore, an event recorder is often more successful. In addition, in patients with organic heart disease and reduced left ventricular function invasive electrophysiologic testing may be more appropriate. In these cases prophylactic implantation of an ICD may be indicated to prevent sudden death. So, in many instances the clinical value of Holter recording is overestimated.     

Evaluation of the usefulness of recording the ECG in the 3rd intercostal space and prevalence of Brugada-type ECG in accordance with recently established electrocardiographic criteria.

BACKGROUND: It has been reported that recording electrocardiograms (ECGs) in the 3rd intercostal space (ICS) is one method that can be used for detecting Brugada syndrome; however, the prevalence of Brugada-type ECGs recorded in the 3rd ICS and the usefulness of recording the ECG in the 3rd ICS in accordance with recently established electrocardiographic criteria is unknown. METHODS AND RESULTS: ECGs were recorded in both the 4th and 3rd ICS in 17 Brugada-type ECG patients (group A) and in 206 consecutive male subjects (group B). Brugada-type ECGs were divided into 3 types. In group A, the prevalence of type 1 ECG, which is a coved-type ECG with ST-segment elevation of >/=2 mm, increased from 23.5% to 64.7% when ECG was recorded in the 3rd ICS. The conversion to type 1 ECG was found to be related to induction of ventricular arrhythmia. In group B, the prevalence of Brugada-type ECG increased from 1.5% to 5.8% when the ECG was recorded in the 3rd ICS. CONCLUSIONS: Recording the ECG in the 3rd ICS is useful for identifying high-risk patients with Brugada-type ECG and for detecting concealed Brugada-type ECG.     

Protection of the abnormal heart

Myocardial ischemia and reperfusion injury have been extensively investigated in the laboratory mainly in healthy tissues. However, in clinical settings, ischemic heart disease coexists with certain illnesses, which could potentially influence the response of the myocardium to ischemia and reperfusion. Recent research has revealed that the abnormal heart may not be always vulnerable to ischemic injury. Furthermore, the effect of powerful means of protection, such as ischemic preconditioning, may not be in operation under certain pathological conditions. With this evidence in mind, the present review will focus on the response of the abnormal heart to ischemia and reperfusion, the possible underlying mechanisms, and potential cardioprotective strategies.     

Dynamic characteristics of the thorax connected with the heart action

We determined the indices of local vibrations (resonance frequency, damping coefficient, stiffness constant, extinction time) and transfer function H(s) . 10(-6) for three somatotypes and three respiratory positions on 88 points of the thorax. The examinees were males (age 21 years). We found the resonance frequencies of 36.86--54.75 cps, damping coefficient (delta) 0.121--0.217. This means the damping is less than critical (delta = 1). We applied shocks (a force of 2 N) with a reflex hammer on 88 points of the thorax. The force diminished from the exciting place (say ictus) to the recording place (accelerometer on the sternum) from 2 to 0.2 N. The athletic type has the highest resonance frequency and stiffness constant; the leptosomic type has the highest damping; the longest extinction time belongs to the pyknic type. The pyknic type has also the highest value of the transfer function. The respiratory position (quiet respiration, Valsalva and Müller experiment) influences the values of the indices of local vibrations and of the transfer function. The influence is evident especially on the intercostal points: the transfer of the oscillations is alleviated at a higher stiffness of the thorax (Valsalva; the value of H(S) . 10(-6) rises from 7.00 to 9.39 sec2), it deteriorates at a small stiffness of the thorax (in Müller's experiment falls to 2.78 sec2). With the fall in the intrathoracic pressure the damping in the intercostal points decreases. On the basis of experiments the conclusion was made that a short testing of the thorax of an examinee will give the dynamic characteristics of the thorax (indices of local vibrations and transfer functions) of the individual. This procedure will alleviate the quantitative use of noninvasive mechanical methods in the assessment of the cardiovascular function.     

Evaluation of the ECG T-wave changes during function tests of ischemic heart disease patients

Differential assessment of T wave changes in response to exercise testing and contrast ventriculography appraising the condition of the coronary bed and intracardiac hemodynamics was performed in 117 patients with coronary heart disease. It is suggested that the T amplitude increasing twofold and more or reversion of the T wave in response to exercise should be considered as an evidence of abnormality.     

Normalization of the ECG in right heart infarct

A 6-month ECG follow-up was carried out in 65 patients with right-ventricular infarction accompanied by anterior (n = 17) and inferior (n = 48) left-ventricular necrosis. QRS morphology and ST-segment alterations were evaluated in the period of rehabilitation and 6 months later. By the end of the 6th month, QRS in V3-4R returned to normal in 12 patients (18%), and there was no ST elevation in any of the patients at that time. Normalizations of QRS in V3-4R was about the same in the two groups and it was independent of patients' ages.     

Exercise testing and portable ECG recording in arrhythmia-prone patients.

To detect transient arrhythmias or conduction disturbances, 200 patients with the symptoms of palpitations, syncope or dizziness, and patients with coronary heart disease, angina pectoris, arrhythmias or conduction disturbances on resting 12-lead electrocardiogram, were studied by submaximal treadmill exercise and portable Holter recording. Thirty-nine patients (19.5%) had arrhythmias on the resting 12-lead ECG, 136 patients (68%) showed arrhythmias either on treadmill or Holter recording or both. Eighty-nine patients (44.5%) showed arrhythmias on exercise, while 123 patients (61.5%) had rhythm or conduction disturbances on Holter recording. Twenty-two patients (11%) had arrhythmias only on treadmill walking, while 68 (34%) had arrhythmias only with the Holter. In six patients different arrhythmias was noted by each method. Although the Holter recording technique affords a higher yield of recording transient arrhythmias than did exercise testing, both methods are useful and complementary in evaluating the ambulatory patients suspected of having rhythm or conduction disturbances.     

精准新心电图对冠心病诊断价值的初步探讨

目的探讨精准新心电图(原尼沙赫电图saah ECG)在冠心病诊断中的临床应用价值。方法应用美国菲士公司生产的PHS-A10检测仪机,分别对81例冠心病患者(冠状动脉造影显示至少一支主要冠脉分支狭窄≥50%)和19例非冠心病患者(冠脉造影显示狭窄程度50%)进行同步精准新心电图及心电图检查;对精准新心电图的两个参数(ST-T段的小波个数及小波在所占时程比例)及心电图(ECG)进行分析。结果精准新心电图、ECG诊断冠心病的敏感性分别为97.5%、69.1%,特异性分别为31.6%、57.9%。结论精准新心电图是一项记录心脏电活动的新技术,对于冠心病的诊断价值其敏感性优于心电图。