Study of cardiac arrhythmias and other forms of conduction abnormality in newborn infants.

In an unselected population of 2030 newborn infants studied by electrocardiography (ECG) between April 1975 and April 1977, 35 were found to have arrhythmias or other cardiac conduction abnormalities. Further investigation by means of 24-hour ECG monitoring showed that apparently serious tachyarrhythmias, such as ventricular tachycardia and slow heart rates associated with sinoatrial block, may be present without clinical disturbance in some newborn babies. Six infants had both bradycardia and tachycardia in the 24-hour recording, although the screening ECG had shown only one of these abnormalities. The alarming ECG appearance of some of the arrhythmias suggested a possible aetiological link with some unexplained sudden infant deaths: a multicentre study could determine this more readily and is therefore recommended.     

Cardiac rhythm abnormalities in patients presenting with transient non-focal neurological symptoms: a diagnostic grey area?

Eighty-nine patients attending neurology clinics with transient non-focal neurological symptoms were studied by routine electrocardiography and 24-hour monitoring of the electrocardiography and 24-hour monitoring of the electrocardiogram. In comparison with 109 control subjects there was no significant overall excess of arrhythmias (age-adjusted odds ratio 1.7, kappa2 = 2.67) except in the subgroup of patients under the age of 30 (odds ratio 11.6, p less than 0.05). Bradyarrhythmias, but not tachyarrhythmias, were significantly more common in the patients (odds ratio 7.4, p less than 0.001),. Since patients can rarely be studied while they are having symptoms a working diagnosis must be based on a balance of probabilities: arrhythmias in young patients, or bradyarrhythmias in any patient, are likely to be clinically relevant. Ambulatory electrocardiographic monitoring contributed to the diagnosis in at least 25 of the patients, Nevertheless, the extent to which further investigations are pursued, and the form of treatment ultimately adopted, must also be influenced by the frequency and severity of the patients'' symptoms.     

A 24-HOUR AMBULATORY ECG MONITORING IN ASSESSMENT OF QT INTERVAL DURATION AND DISPERSION IN ROWERS WITH PHYSIOLOGICAL MYOCARDIAL HYPERTROPHY

Myocardial hypertrophy (MH) due to cardiac pathology is characterized by an increase in QT interval duration and dispersion, while the findings for exercise-induced myocardial hypertrophy are contradictory. The majority of published research findings have not explored this relationship, but there have only been a few conducted studies using 24-hour ECG monitoring. The aim of the study was to determine the QT interval duration and dispersion in short-term and 24-hour ECG in endurance athletes with myocardial hypertrophy and without it. Methods: A total of 26 well-trained rowers underwent a resting 12-lead ECG, 24-hour ECG monitoring and echocardiography. Results: Athletes with MH (n = 7) at rest did not show any increase in QTc interval duration and dispersion, or mean and maximal QTc duration in Holter monitoring compared to athletes without MH (n = 19). Left ventricular mass was not significantly correlated with any QTc characteristics. Furthermore, athletes with MH had significantly longer mean QT (P = 0.01) and maximal QT (P = 0.018) intervals in Holter monitoring and higher 24-hour heart rate variability indexes due to stronger vagal effects. Conclusions: The present study demonstrated that athlete''s heart syndrome with myocardial hypertrophy as a benign phenomenon does not lead to an increase in QT interval duration, or increases in maximal and mean duration in a 24-hour ECG. An increase in QT interval duration in athletes may have an autonomic nature.     

Cardiac arrhythmias in myocardial infarction as an extension of lesions to the myocardium and the state of circulatory efficiency

The study involved 55 patients with the acute myocardial infarction aged between 34 and 69 years (mean 53 years) in whom the relation of cardiac arrhythmias incidence to the extension of myocardial involvement and circulatory efficiency was assessed. All patients were examined clinically, a 24-hour ECG with Holter technique (in the first day, 21st day and 6th months after myocardial infarction) and echocardiographic (Echo-2D) tests were registered. Echocardiography was performed during hospital phase and 6 months after myocardial infarction. Cardiac arrhythmias were evaluated with classification into classes described by Lown. Close relation of serious cardiac arrhythmias with extension of myocardial involvement was noted especially in the acute phase of myocardial infarction. High risk arrhythmias--class IVA, IVB and V were noted in nearly 100% of patients in this phase with cardiac aneurysm, extensive akinesis of apex and anterior wall of the heart. Mean value of the ejection fraction was 31% in this group. Incidence of cardiac arrhythmias did not exceed 40%, ejection fraction was 56% in the group of patients with limited lesions to the heart, e.g. akinesis of the lower wall. Incidence of late cardiac arrhythmias (6 months) did not differ significantly in particular groups of patients. The value of ejection fraction remained, however, on the same level as in the hospital phase of the myocardial infarction.     

Myocardial ischaemia in patients with frequent angina pectoris.

One hundred patients with angina pectoris underwent 16-point electrocardiographic (ECG) mapping of the left hemithorax during a standardised exercise test. Forty-five patients had maximum ST-segment depression at position V5, while 35 had no ECG signs of ischaemia at this position. In 20 V5 was on the edge of the precordial area, which showed less severe ST-depression than the central positions. An Oxford ECG recorder and highspeed analyser were modified and used in 50 of the patients with daily angina for recording ST-segment changes over 24 hours. Serial 24-hour ambulatory recordings from the edge of the precordial area of ischaemia identified during exercise detected a mean of only 14 +/- SD 3% of the episodes of ST-segment changes recorded from the centre of the same area. Only 16 +/- 2% of the episodes detected by ECG were accompanied by chest pain. More episodes occurred between 4 am and 6 am than at any other time during the night. This study shows the importance of recording ECG evidence of ischaemia from the precordial position showing maximum changes during exercise. ECG evidence of ischaemia occurs more frequently than anginal pain. These objective measurements add important information to the frequency of chest pain reported by patients with ischaemic heart disease.     

Controlled evaluation of thermal biofeedback in treatment of elevated blood pressure in unmedicated mild hypertension

In the first of two studies, 42 unmedicated mild hypertensives completed either 16 sessions of thermal biofeedback (TBF) training for hand (7 sessions) and foot (9 sessions) warming or 8 weeks of monitoring BPs at home. There was a trend (p<.10) for more of those treated (57.1%) to have DBPs lower than 90 mm Hg than for those only monitoring BPs at home (33%). Analyses of clinic BP values from random zero sphygmomanometer measurements, from 24-hour ambulatory BP monitoring, and from home BP measurements made by the patient showed no advantage for treatment versus BP monitoring. Sixteen of the 21 patients in BP monitoring were later treated. Analyses of treatment effects across all treated subjects by gender revealed a significant (p=.02) decrease in DBP for treated female subjects (n=13) but not for males (n=24). In the second study the 22 initial treatment successes, that is, those whose DBP was below 90 mm Hg at posttreatment (59.4% of those who completed treatment), were randomized to an intensive follow-up (monthly visits for 6 months, then visits every two months) emphasizing regular home practice with an electronic TBF device or regular follow-up (visits every 3 months). Twelve of the 22 were still normotensive at 12 months. There were no differences at any point during the follow-up between the two conditions in success rate or BPs despite a numerical advantage in reported frequency of home practice by those in the intensive follow-up condition.This research was supported by a grant from NHLBI, HL-31189.     

80例急性心肌梗死患者心电监护及护理

目的总结急性心肌梗死患者心电监护及护理经验。方法对本院性心肌梗死患者及时进行心电监护,对出现的心律失常者进行对症处理。结果本组80例患者中出现心律失常55例,其中室性心律失常48例,临床治愈45例;出现心室颤动7例,4例及时电复律转为窦性心律,3例抢救无效死亡。本组心律失常均发生在心肌梗死后1周内,尤其是发病24小时内,出现最多。结论心律失常是心肌梗死患者常见的并发症,也是患者死亡的主要原因,持续心电监护对患者心律失常的及时发现、明确诊断、指导抢救有重要意义。     

Losartan and acute myocardial infarction in insulin-resistant Zucker fatty rats: reduced ventricular arrhythmias and improved survival

Insulin resistance (IR) and diabetes increase the risk of acute myocardial infarction (MI). Angiotensin receptor blockers (ARBs) have been shown to reduce the risk of cardiovascular events in patients with hypertension and diabetes, and to be beneficial after a large MI. Whether pretreatment with ARBs is beneficial in acute MI is unknown. We evaluated whether pre-, peri-, and post-MI treatment with the ARB losartan improved the outcome in the IR Zucker fatty rat (ZFR). ZFR (n=264) received either losartan (3 mg/kg daily) or vehicle for 7 d prior to MI. Early (24 h) protocol (n=31): ventricular arrhythmias were evaluated post-MI using continuous ambulatory ECG monitoring. Late (38 d) protocol (n=233): losartan was increased to 10 mg/kg daily 10 d post-MI and to 30 mg/kg daily 20 d post-MI. Blood glucose, cardiac hemodynamics and remodeling, GLUT-4, fetal gene expression, and survival were evaluated. In large-MI rats, losartan improved early survival (43% vs. 27% in controls, p=0.01) and late survival (23% vs.15% in controls, p=0.02). Improved early survival was associated with a reduction in ventricular arrhythmias. Losartan reduced pulmonary congestion, cardiac hypertrophy, and fetal gene expression in the absence of statistically significant changes in ventricular dilatation and hemodynamics. Blood glucose and cardiac GLUT-4 expression did not change with losartan. In IR ZFR, losartan improves post-MI survival, likely as a result of an early reduction in ventricular arrhythmias. There was also an associated reduction in pulmonary congestion, hypertrophy, and fetal gene expression.     

Arrhythmia in patients with mitral valve prolapse syndrome and the status of the sympathetic nervous system]

The study aimed at evaluating a possible relationship between the adrenergic system tone determined with the excretion of catecholamines with the urine and an incidence of the ventricular arrhythmias in patients with the mitral valve prolapse. The study included 20 patients (13 women and 7 men aged between 20 and 50 years; mean = 31.6 years) with the mitral valve prolapse syndrome diagnosed with the aid of the patients' history, physical examinations and echocardiography. Echocardiograms have shown anterior mitral leaflet prolapse in 7 patients, posterior mitral leaflet prolapse in 8 patients, and both mitral leaflets prolapse in the remaining 5 patients. Daily excretion of adrenaline and noradrenaline was measured with Van Euler and Lishajko's fluorimetric technique. Cardiac arrhythmias were determined with a 24-hour ECG monitoring and classified according to Lown. Premature ventricular contractions of class I were seen in 1 patient, of class II in 5, class III in 1, class IV in 2, and class V in 3 patients. Holter monitoring technique did not show the arrhythmias in 8 patients. Daily adrenaline and noradrenaline excretion with the urine was within the normal values (3.2-30.8 ug and 0.2-16.2 ug, respectively) in all examined patients. Daily urine noradrenaline was higher in patients with serious ventricular arrhythmias (Lown's class V) than mean values in the whole examined group.     

Thermal biofeedback as an effective substitute for sympatholytic medication in moderate hypertension: A failure to replicate

Thirty-three moderate hypertensives were converted to a 2-drug regimen of metoprolol and diuretic and BPs stabilized at a well-controlled level. They then completed one of three conditions over an 8-week interval: (I) 16 sessions of TBF (hand and foot warming); (II) 16 sessions of frontal EMG-BF; (III) regular home monitoring of BP. Attempts were then made to withdraw the patients from the sympatholytic medication. Those successfully withdrawn were followed up for one year. There were no significant advantages for TBF over the other two conditions in the short term or with long-term follow-up. Only 27% of treated patients (including Condition III failures who were remedicated and treated with TBF) were successfully off of the sympatholytic at a one-year follow-up. The generally poor results on clinical outcome were confirmed by clinic BPs, home BPs by patients, and 24-hour ambulatory BPs.This research was supported by grant No. HL-27622 from NHLBI. The authors wish to thank Dr. Guy C. McCoy for his role in the initial conceptualization of the study, Dr. Jim Jaccard and Barbara Greene for their assistance in the analyses of the 24-hour ambulatory BP data, and Annabel Prins, Bruce Steffek, and Debra Belkin, who served as therapists for a portion of the study.     

Late ventricular potentials--a new risk factor for cardiac arrhythmias in recent myocardial infarction

The study involved 150 patients with recent myocardial infarction. Ventricular lat potentials were registered in these patients during the first 48 hours and repeated in the third week. Ventricular late potentials were found in 31 patients (21%) in the first 48 hours, and in 27 out of 134 patients (20%) before the release from the hospital. Comparing potentials registration in the acute and late phase of the myocardial infarction it was found that ventricular late potentials occurred in 6 and disappeared in 4 patients. Stable ventricular tachycardia was significantly more frequent (p less than 0.001) within the first 48 hours in patients with ventricular late potentials than those without them (19% vs 3%). Ventricular late tachycardia (over 48 hours) was more frequent (p less than less than 0.001) in patients with ventricular late potentials (21% vs 1%). Premature ventricular excitations of Lown class 2-5 were also more frequent (p less than 0.001) in the group of patients with ventricular late potentials than those without these potential (81% vs 24%) when registered with a 24-hour Holter ECG in the third week following myocardial infarction. Antiarrhythmic drugs did not produce the regression of ventricular late potentials. Non-invasive registration of ventricular late potentials helps to select patients with life-threatening ventricular arrhythmias following the acute myocardial infarction.     

Circadian rhythm of spontaneous ventricular arrhythmias in elderly patients with myocardial ischemia at low risk for sudden death]

In 26 patients (65-80 yr) with low risk of sudden death, the circadian rhythm of spontaneous ventricular arrhythmias was analyzed, throughout 72 h, by the Holter monitoring method. The prolonged ECG monitoring is indispensable to evaluate the real necessity of an antiarrhythmic therapy and to establish the therapeutic approach. Premature ventricular complexes (PVC): isolated, couplets and runs of ventricular tachycardia have been considered. The isolated PVC showed uniform distribution throughout 24h, with higher frequency/hour ratio (f/h) in females. Couplets and runs showed circadian diurnal distribution with higher f/h ratio in smokers and males. After analysis of the results, the patients were additionally subdivided into smokers and non-smokers. Since smokers showed a diurnal distribution of all kinds of arrhythmias, antiarrhythmic drugs whose pharmacological peak corresponds to the distribution peaks of arrhythmias were proposed. Non-smokers could be divided into two groups: a) patients with isolated extrasystoles which did not show a circadian rhythm of arrhythmias and who must be treated with retard-drugs, which give protection throughout 24h; b) patients with runs or couplets of PVC showing a circadian rhythm of arrhythmias and who must be treated with drugs whose pharmacological peak corresponds to the distribution peaks of arrhythmias.     

Non-invasive evaluation of function in both cardiac ventricles and arrhythmias in patients with dilated cardiomyopathy]

Resting echocardiography with M-mode technique under the control of bidimensional picture and pulsating Doppler ultra sound and a 24-hour ECG with Holter technique were performed in 19 patients with dilated cardiomyopathy (6 females and 13 males; mean age 46 years, mean duration of the disease 23 months). A group of 7 patients with electrocardiographic features of the left ventricle hypertrophy, according to Sokolov index, was distinguished and compared with a group of patients without ventricular hypertrophy. The symptoms of pulmonary hypertension with progressing dilatation and failure of the right cardiac ventricle were found in patients with dilated cardiomyopathy without coexisting hypertrophy, despite of significant deterioration of the contractive function. Cardiac arrhythmias and thrombotic disorders which are hazardous for life were significantly more frequent (78% and 22%, respectively) in this group. Percentage of sudden deaths in these patients was high (56%).     

老年患者24 小时食管pH 监测的护理

目的:探讨和总结老年人24小时食管pH监测的有效的护理方法.方法:我病区自2010年6月到2010年12月接受24小时食管pH监测的患者共50例,分为老年组(≥60岁)和非老年组,采用使用电池的动态pH监测仪进行监测.结果:本研究的50例老年患者中,46例置管一次成功,4例因咽部敏感给予2%的利多卡因10ml咽下后第二次均置管成功.本组检查后无一例造成咽部及胃部的损伤,无误吸等并发症发生.结论:24小时食管pH监测是一种安全、简便、无创伤、客观的检查技术,通过动态pH监测,可检测有无胃食管反流,并算出食管真正接触到反流胃酸的时间.正确的操作方法及细致到位的护理可减少老年患者检查时的痛苦,并有效预防并发症的发生.     

Tendinous cords in echocardiographic studies--occurrence, clinical significance

Tendinous chords inside cardiac ventricles were found in 53 (5.6%) out of 954 individuals examined echocardiographically within one year. Only 30 individuals were further analysed. No marked pathology in the cardiovascular system was found. Tendinous chord was localized in the right ventricle in 7 individuals, in left ventricle in 21, and in both ventricles in 2 subjects. Ventricular arrhythmias were shown in 11 subjects (36.6%) with the aid of a 24-hour ECG monitoring with Holter's technique. They were of the II and IV stage of advancement according to Lown's classification. Ventricular rhythm disorders were seen in both subjects with tendinous chord within left ventricle (7 subjects) and in the right ventricle (4 subjects). Local diastolic disorders with no effect on the ejection fraction were noted in all subjects with false chord and ventricular rhythm disorders. Ventricular cardiac rhythm disorders are being observed in the subjects with the false chord located within the right or the left cardiac ventricle producing local diastole disturbances.     

Overexpression of cardiac connexin45 increases susceptibility to ventricular tachyarrhythmias in vivo

Electrophysiological remodeling involving gap junctions has been demonstrated in failing hearts and may contribute to intercellular uncoupling, delayed conduction, enhanced arrhythmias, and vulnerability to sudden death in patients with heart failure. Recently, we showed that failing human hearts exhibit marked increases in connexin45 (Cx45) expression in addition to previously documented decreases in connexin43 (Cx43) expression. Each of these changes results in reduced gap junction coupling. The objective of the present study was to examine functional consequences of increased Cx45 in cardiac gap junctions. Transgenic mice with cardiac-selective overexpression of the developmentally downregulated cardiac connexin, connexin45 (Cx45OE mice) were subjected to in vivo electrophysiology studies in which an intracardiac catheter was used to induce ventricular arrhythmias in anesthetized mice, and in which ambulatory ECG monitoring was used to detect spontaneous arrhythmias in unanesthetized mice. Hearts were analyzed by TaqMan RT-PCR, immunostaining, immunoblotting, and echocardiography. Lucifer yellow and neurobiotin dye transfer was used to assess coupling in transgenic and control myocyte cultures. Cx45 mRNA was two orders of magnitude greater in Cx45OE mice. Cx45-immunoreactive signal at gap junctions increased twofold and total Cx45 protein by immunoblotting increased 25% in Cx45OE mice compared with nontransgenic littermate controls. Functionally, Cx45OE mice exhibited more inducible ventricular tachycardia than controls but did not exhibit any other functional or structural derangements as assessed by echocardiography. Ventricular myocytes isolated from Cx45OE mice exhibited diminished intercellular transfer of Lucifer yellow dye and increased transfer of neurobiotin, consistent with altered cell-to-cell communication. Thus increased myocardial expression of Cx45 results in remodeling of intercellular coupling and greater susceptibility to ventricular arrhythmias in vivo.     

24-hour recording in personnel employed in the intensive cardiac care unit]

The authors, expecting confirmation of arrhythmogenic effects of work at the Intensive Cardiological Care Unit (ICCU), recorded a 24-hour ECG in the employed staff. Together 20 healthy individuals (mean age 31.6 years) were tested. ECG was recorded twice at the unit, and repeated at home. Ventricular arrhythmia was noted in 60% of tested individuals at home (mean number of excitations 6 per 24 hours). It was 2.5 times more frequent at ICCU (mean number of excitations 15 per 24 hours) involving 75% of tested individuals. Atrial arrhythmia was noted also in 60% of the tested individuals at home (mean number 16 per 24 hours) whereas it was noted in 85% of the tested individuals at ICCU, i.e. 2.5 times more frequently than at home (mean value 40/24 hours). Both atrial and ventricular arrhythmias are significantly more frequent during night rest at ICCU than that at home. Results suggest that the employment at ICCU is arrhythmogenic.     

A mobile one-lead ECG device incorporated in a symptom-driven remote arrhythmia monitoring program. The first 5,982 Hartwacht ECGs

Background

In recent years many mobile devices able to record health-related data in ambulatory patients have emerged. However, well-organised programs to incorporate these devices are sparse. Hartwacht Arrhythmia (HA) is such a program, focusing on remote arrhythmia detection using the AliveCor Kardia Mobile (KM) and its algorithm.

Objectives

The aim of this study was to assess the benefit of the KM device and its algorithm in detecting cardiac arrhythmias in a real-world cohort of ambulatory patients.

Methods

All KM ECGs recorded in the HA program between January 2017 and March 2018 were included. Classification by the KM algorithm was compared with that of the Hartwacht team led by a cardiologist. Statistical analyses were performed with respect to detection of sinus rhythm (SR), atrial fibrillation (AF) and other arrhythmias.

Results

5,982 KM ECGs were received from 233 patients (mean age 58 years, 52% male). The KM algorithm categorised 59% as SR, 22% as possible AF, 17% as unclassified and 2% as unreadable. According to the Hartwacht team, 498 (8%) ECGs were uninterpretable. Negative predictive value for detection of AF was 98%. However, positive predictive value as well as detection of other arrhythmias was poor. In 81% of the unclassified ECGs, the Hartwacht team was able to provide a diagnosis.

Conclusions

This study reports on the first symptom-driven remote arrhythmia monitoring program in the Netherlands. Less than 10% of the ECGs were uninterpretable. However, the current performance of the KM algorithm makes the device inadequate as a stand-alone application, supporting the need for manual ECG analysis in HA and similar programs.

     

ST段抬高性和非ST 段抬高性急性心肌梗死患者的冠状动脉病变特点比较

目的:比较ST段抬高性和非ST段抬高性急性心肌梗死患者的冠状动脉病变特点。方法:选取100例在我院接受24h动态心电图和冠状动脉造影检查的急性心肌梗死患者,根据心电图结果分为观察组和对照组各50例。对照组为ST段抬高性心肌梗死(STEMI)患者,观察组为非ST段抬高性心肌梗死(NSTEMI)患者,比较两组患者冠状动脉病变的差异。结果:对照组LAD(左前降支)闭塞血管比例(52.00%)显著高于观察组(18.00%),差异具有统计学意义(P0.05)。对照组LCX(回旋支)闭塞血管比例(8.00%)显著低于观察组(50.00%),差异具有统计学意义(P0.05)。对照组RCA(右冠脉主干)闭塞血管比例(40.00%)和观察组(30.00%)比较,差异无统计学意义(P0.05)。对照组单支病变比例(46.00%)明显高于观察组(12.00%),对照组三支病变比例(20.00%)明显低于观察组(48.00%)比较,差异均具有统计学意义(P0.05)。对照组二支及正常血管比例与观察组比较,差异均无统计学意义(P0.05)。对照组罪犯血管狭窄程度在76%-90%、91%-99%及完全闭塞的比例与观察组比较差异均具有统计学意义(P0.05)。罪犯血管狭窄程度在50%及50%-75%时,两组差异无统计学意义(P0.05)。两组并发症发生情况比较,差异无统计学意义(P0.05)。结论:1NSTEMI罪犯血管闭塞以LCX多见,STEMI罪犯血管闭塞以LAD多见;2NSTEMI以三支血管病变较多见,STEMI以单支病变较多见。     

老年原发性高血压患者血压晨峰与早期肾损害的临床观察

目的:探讨老年原发性高血压患者血压晨峰与早期肾损害的关系。方法:选择我院收治的94例老年原发性高血压患者进行24小时动态血压监测,并根据监测结果,将患者分为晨峰组62例和非晨峰组32例,检测和比较两组的血肌酐和尿素氮、12小时尿微量蛋白、尿β2微球蛋白、空腹血糖、血脂等指标。结果:老年高血压患者晨峰组12小时尿微量蛋白、尿β2微球蛋白均显著高于非晨峰组(P0.05);晨峰血压与12小时尿微量白蛋白(r=0.374)、尿β2微球蛋白(r=0.456)呈显著正相关。结论:老年原发性高血压患者血压晨峰与早期肾损害有关,治疗高血压的同时重视控制晨峰血压有重要意义。