Treatment efficiency evaluation of left cardiac sympathetic denervation for patients with inherited arrhythmia by exercise-stress test / 中华心血管病杂志

Objective: To evaluate the efficiency of left cardiac sympathetic denervation (LCSD) in inherited arrhythmia patients with adrenergic activity-induced malignant ventricular arrhythmia, and observe exercise-stress test features before and after LCSD. Methods: This retrospective observational study included catecholaminergic polymorphic ventricular tachycardia(CPVT) and long QT syndromes(LQTS) patients who underwent video-assisted LCSD at Beijing Tsinghua Changgung Hospital and Peking University People's Hospital from September 2006 to May 2020. The indications for LCSD surgery were intolerant or refractory to beta-blocker medication. Clinical and exercise-stress tests data of included patients were collected before and 1 month after LCSD. Heart rate, exercise tolerance, atrial and ventricular arrhythmia, QTc interval and predictors for sudden cardiac death were analyzed. Patents were regularly followed up at 1, 3, 6, and 12 months after LCSD and then once every year thereafter. Cardiac events and medication adjustment records were collected. Results: Five patients (2 CPVT, 1 LQT1, and 2 LQT2)were included in the study. All patients experienced syncope as first symptom at the median age of 12(10, 16)years, and underwent LCSD at the median age of 21(16, 26)years, Baseline heart rate was similar before and after LCSD ((65.6±6.5) beats/min vs. (68.0±11.1) beats/min, P=0.57); while maximum workload tended to be lower after LCSD ((12.1±2.8) metabolic equivalents (METS) before surgery vs. (10.5±2.4) METS after surgery, P=0.07). Incidence of atrial and ventricular arrhythmia were significantly reduced post LCSD, and the ventricular arrhythmia score was decreased after LCSD in CPVT patients (4 points before LCSD vs. 3 points after LCSD in case 1;5 points before LCSD vs. 3 points after LCSD in case 2). QTc interval was shortened significantly in three LQTs patients (QTc interval at baseline heart rate: (546.6±72.3) ms before surgery vs. (493±61.1) ms after LCSD, P=0.047; QTc interval at maximal exercise heart rate: (516.3±73.7) ms before surgery vs. (486.7±64.2)ms after LCSD, P=0.035). Additionally, sudden cardiac death risk indicator ΔHRR1 (heart rate decreasing value within the first 1 min during recovery phase) decreased from (51.5±21.1) beats/min before surgery to (32.0±13.9) beats/min after surgery (P=0.035). During a median follow-up of 1(1, 4) year, all five patients were on low dosage of propranolol (37.0±21.7) mg/d. Cardiac events free survival was achieved in four out of 5 patients (80%) after sympathectomy, while 1 case suffered from sudden cardiac death after emotional stress. Conclusion: LCSD surgery can be safely and effectively performed in most hereditary arrhythmia patients with adrenergic activity-induced life-threatening cardiac events. Exercise stress test results show that LCSD could reduce malignant arrhythmias and improve sudden cardiac death risk indicators without decreasing heart rate.

Re-evaluation of transvenous lead extraction with modified standard technique: A prospective study in 229 patients / 华中科技大学学报（医学）（英德文版）

As new-type powered sheaths are expensive and unavailable, the standard lead extraction techniques remain the mainstay in clinical applications in many countries. The purpose of this study was to re-evaluate the clinical application of the standard lead extraction techniques and equipment, and make some procedural modifications and innovations. In our center, between January 2006 and May 2012, 229 patients (median, 66 years) who underwent lead extraction due to infection and lead malfunction were registered and followed up prospectively with respect to clinical features, reasons for lead extraction, technical characteristics, and clinical prognosis. A total of 440 leads had to be extracted transvenously by using special tools from 229 patients (male, 72.1%). Vegetations ≥1 cm were detected in six patients. Locking Stylets were applied for 398 (90.5%) leads. Telescoping dilator polypropylene sheaths and counter traction technique were used for 202 (45.9%) leads due to lead adhesion, and the mean implant duration of the 202 leads was longer than the other 238 leads (48.9±22.6 vs. 26.6±17.8 months; P <0.01). In addition, modified isolation and snare techniques were used for 56 leads (12.7%). Minor and major procedure-related complications occurred in three (1.3%) and four (1.7%) cases respectively, including one death (0.4%). Severe lead residue occurred in one case. Complete procedural success rate was 96.1% (423/440), and clinical success rate was 98.9% (435/440). The median follow-up period was 18 (1-76) months. No infection- and procedure-related death occurred in our series. Our data demonstrated that high clinical success rate of transvenous lead extraction can be guaranteed by making full use of the standard lead extraction techniques and equipment with individualized modifications.

Effect of the smoking cessation services in the out-patient department for patients with coronary heart disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the effects and clinical prognosis of out-patient department-based smoking cessation services for coronary heart disease (CHD) patients.</p><p><b>METHODS</b>A total of 140 smoking patients diagnosed with coronary heart disease in our cardiovascular department were randomly divided into the intensive smoking cessation clinic follow-up group (intervention group, patients were informed on the importance and methods to quit smoking at the first visit and reminded for that at months interval for 6 months, n = 70) and the conventional treatment group (control group, n = 70). After 6 months, the smoking status, cardiovascular event rates, drug usage, out-patient medical costs and quality of life were compared between the two groups.</p><p><b>RESULTS</b>Age, gender, concomitant diseases, drug usage were similar between the two groups at baseline (all P > 0.05). After 6 months, smoking quit rate [34.2% (24/70) vs. 5.7% (4/70), P < 0.01], drug use rates: lipid-lowering drugs [95.3% (67/70) vs. 80.4% (56/70)], β blockers [82.4% (57/70) vs. 41.3% (28/70)], and ACEI/ARB [61.4% (43/70) vs. 34.4% (24/70)] were significantly higher in the intervention group than in the control group, while total cardiovascular event rates [21.4% (15/70) vs. 47.1% (33/70), P < 0.01] and out-patient medical costs (3789.3 RMB vs. 4984.2 RMB, P < 0.01) were significantly lower in the intervention group than in the control group. The quality of life scores derived from MYO health survey questionnaire was significantly higher in the intervention group than in the control group (P < 0.01). The top three reasons responsible for continuous smoking for all patients failed to quit smoking were: (1) others smoked more than me and still alive and healthy [90.3% (56/62)]; (2) smoking helped me to keep relaxed and reduce trouble in daily work and life [70.9% (44/62)]; (3) smoking was essential while chatting and drinking with friends [66.1% (41/62)]. The overall satisfactory rate to this smoking cessation program was 42.8% and the satisfactory rate was up to 50.0% by patients.</p><p><b>CONCLUSIONS</b>Intensive outpatient smoking cessation follow-up program can significantly improve the smoking cessation rates, the guideline drug use rate and the quality of life while reduce medical costs for coronary heart disease patients.</p>

A novel deletion-frameshift mutation in the S1 region of HERG gene in a Chinese family with long QT syndrome / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The congenital Long QT syndrome (LQTS) is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval, syncope, ventricular arrhythmias, and sudden death. The chromosome 7-linked type 2 congenital LQTS (LQT2) is caused by gene mutations in the human ether-a-go-go-related gene (HERG).</p><p><b>METHODS</b>A Chinese family diagnosed with LQTS were screened for KCNQ1, HERG and SCN5A, using polymerase chain reaction (PCR), direct sequencing, and clong sequencing. We also investigated the mRNA expression of the HERG gene.</p><p><b>RESULTS</b>We identified a novel I414fs + 98X mutation in the HERG gene. The deletion mutation of 14-bp in the first transmembrane segment (S1) introduced premature termination codons (PTCs) at the end of exon 6. This mutation would result in a serious phenotype if the truncated proteins co-assembled with normal subunit to form the defective channels. But only the proband was symptomatic.</p><p><b>CONCLUSIONS</b>We found that the mRNA level of the HERG gene was significantly lower in I414fs + 98X carriers than in noncarriers. We found a novel I414fs + 98X mutation. The mRNA level supports that NMD mechanism might regulate the novel mutation.</p>

Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure.</p><p><b>METHODS</b>Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects.</p><p><b>RESULTS</b>(1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P < 0.01] was significantly higher while education level were significantly lower in passive smoking group than in control group. Passive smokers were more likely service industry workers [29.07% (25/86) vs. 15.00% (12/80), P < 0.05] and had longer daily working time [(7.56 ± 1.24) h vs. (6.02 ± 0.96) h, P < 0.01], and were less likely to be professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P < 0.05] and managers [13.95% (12/86) vs. 38.75% (31/80), P < 0.01] compared to controls. The main place of passive smoking was workplace (67.44%, 58/86), entertainment venues (63.95%,55/86), restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P < 0.05). Every 5 min average of the standard deviation of sinus RR cycle (SDNN index) and 24 h every 5 min sinus RR interval mean standard deviation (SDANN) were similar between the 2 groups (all P > 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in the control group (all P < 0.01). (3) Heart rate and diastolic blood pressure were significantly higher in passive smoking group than in control group (all P < 0.05) while systolic blood pressure was similar between the 2 groups (P > 0.05).</p><p><b>CONCLUSIONS</b>Marriage status, education level, profession and daily working time are independent determinants for passive smoking. Passive smoking mainly occurred in the workplace, entertainment venues and restaurants. Passive smoking is linked with reduced heart rate variability, increased 24 h average heart rate and diastolic blood pressure.</p>

Types and risk factors of arrhythmia on young patients with acute coronary syndrome in Henan province / 中华心血管病杂志

<p><b>OBJECTIVE</b>The types and risk factors of arrhythmia were analyzed on acute coronary syndrome (ACS) patients under the age of 44 years who were hospitalized in Henan province between September 2009 to June 2012.</p><p><b>METHODS</b>Medical records of eligible patients were obtained from the information system of the First Affiliated Hospital of Zhengzhou University teleconsultation information center. Middle aged and elderly ACS patients who were hospitalized at the same period served as controls. Data on arrhythmia types, blood pressure, thyroid disease, respiratory sleep apnea syndrome, smoking history, history of alcohol consumption, eating habits, family history of early-onset arrhythmia, laboratory tests were analyzed.</p><p><b>RESULTS</b>(1) Arrhythmia was detected in 110 out of young ACS patients (55%), which was significantly lower than that in the elderly ACS patients (71.05%, P < 0.01). (2) The top three arrhythmias in young ACS patients were: sinus tachycardia (30.50%), the premature ventricular contractions (19.00%), atrial flutter/atrial fibrillation (16.50%). Incidence of sinus tachycardia, atrial flutter/atrial fibrillation were significantly higher while incidence of ventricular tachycardia, ventricular fibrillation, paroxysmal supraventricular tachycardia were significantly lower in young ACS patients than in middle-aged ACS patients (all P < 0.05). The incidence of sinus tachycardia was higher while incidence of ventricular premature accelerated ventricular spontaneous cardiac rhythm, ventricular tachycardia, ventricular fibrillation, non-paroxysmal supraventricular tachycardia, atrial flutter/atrial fibrillation, paroxysmal supraventricular tachycardia, sinus bradycardia, nodal escape, atrioventricular block were significantly lower in young ACS patients than in elderly ACS patients (all P < 0.05). (3) Body mass index, incidence of smoking, coronary three-vessel disease, drinking, eating salty foods, thyroid dysfunction, sleep apnea were significantly higher in youth ACS patients with arrhythmia than in young ACS patients without arrhythmia (all P < 0. 05). (4) Logistic regression analysis found that number of diseased coronary vessels (OR = 24.293), smoking (OR = 1.112) and alcohol consumption (OR = 1.039) were independent risk factor for developing arrhythmia in young ACS patients from Henan province.</p><p><b>CONCLUSIONS</b>The main types of arrhythmia are sinus tachycardia, premature ventricular contractions, atrial flutter/atrial fibrillation and the major risk factors related to the arrhythmia are number of diseased coronary vessels, smoking and alcohol consumption in young ACS patients from Henan province.</p>

Re-evaluation of transvenous lead extraction with modified standard technique: a prospective study in 229 patients / 华中科技大学学报（医学）（英德文版）

As new-type powered sheaths are expensive and unavailable, the standard lead extraction techniques remain the mainstay in clinical applications in many countries. The purpose of this study was to re-evaluate the clinical application of the standard lead extraction techniques and equipment, and make some procedural modifications and innovations. In our center, between January 2006 and May 2012, 229 patients (median, 66 years) who underwent lead extraction due to infection and lead malfunction were registered and followed up prospectively with respect to clinical features, reasons for lead extraction, technical characteristics, and clinical prognosis. A total of 440 leads had to be extracted transvenously by using special tools from 229 patients (male, 72.1%). Vegetations ≥1 cm were detected in six patients. Locking Stylets were applied for 398 (90.5%) leads. Telescoping dilator polypropylene sheaths and counter traction technique were used for 202 (45.9%) leads due to lead adhesion, and the mean implant duration of the 202 leads was longer than the other 238 leads (48.9±22.6 vs. 26.6±17.8 months; P <0.01). In addition, modified isolation and snare techniques were used for 56 leads (12.7%). Minor and major procedure-related complications occurred in three (1.3%) and four (1.7%) cases respectively, including one death (0.4%). Severe lead residue occurred in one case. Complete procedural success rate was 96.1% (423/440), and clinical success rate was 98.9% (435/440). The median follow-up period was 18 (1-76) months. No infection- and procedure-related death occurred in our series. Our data demonstrated that high clinical success rate of transvenous lead extraction can be guaranteed by making full use of the standard lead extraction techniques and equipment with individualized modifications.

Ventricular synchronicity: observations comparing pulse flow and tissue Doppler assessment in a Chinese healthy adult cohort / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mechanical asynchrony is an important parameter in predicting the response to cardiac resynchronization therapy, but detailed knowledge about cardiac timing in healthy persons is scarce. Therefore, in the current study, we sought to investigate the physiological status of interventricular synchronicity using pulse wave flow and tissue Doppler imaging in a healthy Chinese population.</p><p><b>METHODS</b>Eighty-eight healthy volunteers underwent standard flow and tissue Doppler echocardiographic examinations. Ventricular inflow and outflow pulse wave flow Doppler patterns were recorded together with annulus pulse tissue Doppler imaging. Time intervals from the beginning of the QRS complex to the onset, peak and end of each wave were measured.</p><p><b>RESULTS</b>The onsets of systole between left and right ventricles were highly synchronized by both imaging modalities. However, the left ventricle reached the peak flow ejection and peak mechanical contraction earlier than the right ventricle, (165.61 ± 26.23) ms vs. (204.3 ± 34.55) ms (P < 0.01) and (133.62 ± 26.19) ms vs. (191.25 ± 38.47) ms (P < 0.01). Time to peak early diastolic relaxation was earlier in the left ventricle than in the right heart, (500.23 ± 56.52) ms vs. (524.94 ± 47.42) ms (P < 0.01).</p><p><b>CONCLUSIONS</b>Left and right ventricles were well synchronized at the onsets of systole and diastole even though interventricular peak systolic and peak early diastolic dyssynchrony was observed in healthy people by pulse wave Doppler imaging. In addition, diastolic timing events were slightly affected by age and gender.</p>

Percutaneous extraction of leads from coronary sinus vein and branch by modified techniques / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cardiac resynchronization therapy (CRT) device and coronary sinus (CS) lead extraction are required due to the occurrence of systemic infection, malfunction, or upgrade. Relevant research of CS lead extraction is rare, especially in developing countries because of the high cost and lack of specialized tools. We aimed to evaluate percutaneous extraction of CS leads by modified conventional techniques.</p><p><b>METHODS</b>Of 200 patients referred for lead extraction from January 2007 to June 2011, 24 (12.0%) involved CS leads (24 CS leads). We prospectively analyzed clinical characteristics, optimized extraction techniques and feasibility of extraction.</p><p><b>RESULTS</b>Complete procedural success was achieved in 23 patients (95.8%), and the clinical success in 24 patients (100.0%). The leading indication for CS lead extraction was infection (66.7%). Mean implant duration was (29.5 ± 20.2) months (range, 3 - 78 months). Sixteen CS leads (66.6%) were removed with locking stylets plus manual traction by superior transvenous approach. Mechanical dilatation and counter-traction was required to free fibrotic adhesions and extract 4 CS leads (16.7%), which had longer implant duration than other leads ((62.5 ± 12.3) vs. (22.9 ± 14.1) months, P < 0.05). Another 4 CS (16.7%) leads were removed by modified and innovative snare techniques from femoral vein approach. Median extraction time was 11 minutes (range, 3 - 61 minutes) per CS lead, which had significant correlation with implant duration (r = 0.8, P < 0.001). Sixteen patients (66.6%) were reimplanted with new devices at a median of 7.5 days after extraction. Median followed-up was 23.5 months (range, 8 - 61 months), three patients died due to sudden cardiac death (26 months), heart failure (45 and 57 months, respectively).</p><p><b>CONCLUSION</b>The modified procedure was proved to be practical for percutaneous extraction of CS leads, especially in developing countries lacking expensive powered sheaths.</p>

Assessment of left ventricular systolic synchronicity by quantitative tissue velocity imaging in patients with left ventricular noncompaction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To assess left ventricular systolic synchronicity by quantitative tissue velocity imaging (QTVI) in patients with left ventricular noncompaction (LVNC).</p><p><b>METHODS</b>Eighteen LVNC patients and 30 healthy controls were included. Two-dimensional echocardiography, QTVI was applied on parasternal long axis view, apical two-chamber and four-chamber view. Tissue velocity curve was obtained from the middle and basal segments of left ventricular posterior, lateral, septal, anterior, inferior and anteroseptal walls. Time interval from the beginning of QRS complex to the peak systolic velocity (Q-Ts) and the maximal difference in Ts among all 12 LV segments (Max-DeltaTs) was calculated.</p><p><b>RESULTS</b>Q-Ts from basal and middle segments of left ventricular inferior, lateral and posterior walls was significantly prolonged in LVNC patients compared to controls (P < 0.001). Max-DeltaTs was also significantly increased in LVNC patients [(161.9 +/- 93.2) ms] than that in controls [(61.2 +/- 27.4) ms, P < 0.001].</p><p><b>CONCLUSIONS</b>There was significant left ventricular asynchronies in patients with LVNC and delayed systolic contraction occurred mostly in the basal and middle segments of left ventricular inferior, posterior and lateral walls.</p>

Electrophysiological characterization and efficacy of radiofrequency ablation of focal atrial tachycardia originating from the left atrial appendage / 中华心血管病杂志

<p><b>OBJECTIVE</b>To analyze the electrophysiological characteristics and efficacy of radiofrequency catheter ablation (RFA) of focal atrial tachycardia (AT) originating from the left atrial appendage (LAA).</p><p><b>METHODS</b>Electrophysiologic study and RFA were performed in 9 patients (4 female) with focal AT originating from the LAA. Atrial appendage angiography was performed to identify the origin of AT. P waves were classified as negative, positive, isoelectric, or biphasic.</p><p><b>RESULTS</b>The mean age was (21 +/- 9) years. AT occurred spontaneously or was induced by isoproterenol infusion rather than programmed extrastimulation and burst atrial pacing. A characteristic P-wave morphology and endocardial activation pattern were observed. Positive P-wave in inferior leads was seen in all patients, upright or biphasic (+/-) component P wave was observed in lead V1, isoelectric component or an upright component P wave with low amplitude ( < 0.1 mV) was seen in lead V2-V6. Earliest endocardial activity occurred at the distal coronary sinus (CS) in all patients. The earliest endocardial activation at the successful RFA site occurred (36.7 +/- 7.9) ms before the onset of P wave. RFA was successful in all 9 patients immediately post procedure. AT reoccurred in 2 patients within 1 month post RFA and AT disappeared post the 2nd-RFA. AT reoccurred in 1 patient and terminated after the 3rd RFA. At the final follow-up (12 +/ 5) months, all 9 patients were free of arrhythmias without antiarrhythmic drugs.</p><p><b>CONCLUSIONS</b>The LAA is an uncommon site of origin for focal AT. The characteristic P wave and activation timing are suggestive for focal AT originating from the LAA. LAA focal ablation is safe and effective for patients with focal AT originating from the LAA.</p>

Efficacy of minimally invasive left ventricular epicardial lead placement for cardiac resynchronization therapy / 中华心血管病杂志

<p><b>OBJECTIVE</b>Ventricular resynchronization might be achieved via minimally invasive left ventricular epicardial lead placement.</p><p><b>METHOD</b>Six patients with congestive heart failure underwent minimally invasive left ventricular epicardial lead placement after failed coronary sinus cannulation were followed up for 1 year, cardiac function and LV lead threshold were evaluated.</p><p><b>RESULTS</b>There were no in-hospital deaths, intraoperative complications and diaphragm stimulation. Correct lead positioning was achieved in all 6 patients. LV lead thresholds remained unchanged [(1.2 ± 0.5) V vs (1.1 ± 0.4) V, P = 0.68] at 12 months follow-up. Improvements on 6 min walking test [(327 ± 77) m vs (267 ± 68) m, P = 0.001], LVEF [(26.1 ± 6.0)% vs (38.2 ± 4.7)%, P = 0.004], and NYHA functional class were evidenced at 12 months follow-up.</p><p><b>CONCLUSION</b>Minimally invasive left ventricular epicardial lead placement is a safe and reliable technique and should be considered as an alternative option in case of difficult coronary venous anatomy and inability to position the lead for resynchronization therapy.</p>

Coronary characteristics of young smokers with coronary heart disease and the effects of tobacco control on smoking cessation / 中华心血管病杂志

<p><b>OBJECTIVE</b>Coronary features of young smokers and non-smokers with coronary heart disease were compared and the effect of tobacco control education was analyzed.</p><p><b>METHODS</b>A total of 160 young patients (14 - 35 years old) diagnosed with coronary heart disease by coronary angiography were included in this study, patients were followed up for 3 months. There were 118 smokers and 42 non-smokers, smokers were further divided to psychological counseling intervention group (68 cases) and control group (50 cases), non-smokers were also divided into psychological counseling intervention group (22 cases) and control group (20 cases).</p><p><b>RESULTS</b>Incidence of single-vessel lesion (50.84% vs. 66.67%) was significantly lower, acute coronary syndrome (75.42% vs. 50.00%), double-vessel lesions (24.58% vs. 19.05%), three-vessel lesions (11.86% vs. 4.74%) as well as coronary artery ectasias (12.71% vs. 9.52%) was significantly higher in smokers than in non-smokers. Gensini scores (61.94 ± 40.35 vs. 45.08 ± 28.97) was significantly higher in smokers than in non-smokers (all P < 0.05). At the end 3-months follow up, smoking cessation rate was significantly higher in psychological counseling intervention group than in control group (61.76% vs. 30.00%, P < 0.05). New smokers was zero in psychological counseling intervention group and 1 in control group among previous non-smokers.</p><p><b>CONCLUSION</b>Smoking is linked with severe coronary artery lesion in young patients with coronary heart disease and psychological counseling intervention could significantly increase the short-term successful smoking cessation rate in these patients.</p>

Clinical characteristics and treatment of a Chinese family with congenital short QT syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the clinical characteristics and therapeutic efficacy of a Chinese family with congenital short QT Syndrome (SQTs).</p><p><b>METHODS</b>Fourteen family members including the proband were screened with routine clinical examination, serum electrolyte, serum myocardial enzymes, electrocardiography (ECG), Holter recording, treadmill exercise test, echocardiography and chest radiograph. High risk patient received intracardiac electrophysiological study (EPS).</p><p><b>RESULTS</b>Among the fourteen family members, 4 members died of sudden cardiac death at young ages, 4 members including the proband and his two daughters and one son were diagnosed as SQTs with structurally intact hearts. Initial ECG in these subjects revealed sinus rhythm with a high peaked T wave, QTc interval </= 320 ms and QT/QTp < 80%. The proband was a 45-year-old man presented with occasional dizziness and family history of sudden cardiac death. Polymorphic ventricular tachyarrhythmias and ventricular fibrillation as well as syncope were induced in this patient during programmed stimulation (S1 = 400 ms, S2 = 250 ms, S3 = 140 ms) from right ventricular outflow tract and a dual chamber Implantable Cardioverter Defibrillator (ICD) was implanted and the patient remained asymptomatic during the 6 months follow up.</p><p><b>CONCLUSIONS</b>SQTs could be presented as an inherited disorder with increased risk for arrhythmias and sudden cardiac death. ICD implantation is the first-choice therapy for high risk patients.</p>

The study of inhibiting heart rate and rapidly terminating atrial flutter of ibutilide on canine / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the electrophysiological effects of ibutilide on canine and to explore the potential mechanisms of ibutilide on terminating atrial flutter.</p><p><b>METHODS</b>Eighteen mongrel dogs were anesthetized and intubated. The heart was exposed through thoracotomy for electrodes implantation. The electrophysiologic variables (heart rate, the conduction of intraatrium and interatrium, the conduction ratio of isthmus, the effective refractory period) were measured in the absence or presence of ibutilide (10 minute infusion with 0.10 mg/kg ibutilide, 30 minutes later with a maintaining dose of 0.01 mg/min).</p><p><b>RESULTS</b>Ibutilide significant suppressed sinus atrial node function, the peak effect was observed at 20 - 30 min post drug infusion and heart rate returned to normal at 2 hours post infusion. Post ibutilide infusion, 1 canine developed sinus pause for 5 seconds and 2:1 atrioventricular conduction block was evidenced in another canine. The atrial, ventricular and pulmonary vein effective refractory periods were all significant prolonged (all P < 0.05) post ibutilide infusion. However, conduction of intraatrium, interatrium and isthmus remained unchanged post ibutilide infusion (all P > 0.05).</p><p><b>CONCLUSIONS</b>Ibutilide could suppress sinus atrial node and the atrioventricular node function. The mechanism of ibutilide on rapidly terminating atrial flutter might be related to the prolongation of the refractory periods which might then result in the reduction of the whole excitable gap of the reentrant circuit and induce proceed inability of reentrant wavefront.</p>

Effects of intracoronary autologous bone marrow mononuclear cells transplantation in patients with anterior myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVES</b>To investigate the efficacy of intracoronary transfer of autologous bone marrow mononuclear cells (ABMMNCs) to patients with myocardial infarction (MI) on left ventricular function and myocardial perfusion.</p><p><b>METHODS</b>Thirty-five patients with MI (> 4 weeks) were enrolled in this prospective, open-labeled study (20 patients in cell transplantation group; 15 patients in control group). All patients were treated by standard drug therapy and percutaneous coronary intervention (PCI). Baseline and 3 months follow-up evaluations included complete clinical and laboratory examinations, six minutes walk test, echocardiography, Dual-isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) and cardiac magnetic resonance imaging (MRI).</p><p><b>RESULTS</b>Baseline parameters were similar between the two groups. NYHA classification and six minutes walk test at 3 months follow-up were also similar between the two groups. However, left ventricular ejection fraction (LVEF) determined by echocardiography and DISA-SPECT was significantly higher; regional wall motion measured by echocardiography and cardiac MRI, myocardial viability and myocardial perfusion in the infarct zone assessed by DISA-SPECT were all significantly improved than before transplantation and than that in control group at 3 months follow-up.</p><p><b>CONCLUSIONS</b>Our results indicate that intracoronary transplantation of ABMMNCs could improve the left ventricular systolic function and beneficially affect myocardial perfusion up to 3 months post transplantation in patients with myocardial infarction.</p>

Electrophysiological characteristics of peri-cingulum atrial tachycardia and its treatment with radiofrequency ablation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To analyze the characteristics of atrial tachycardia originating from the atrioventricular cingulum.</p><p><b>METHOD</b>The electrophysiological mechanism, ablation site graph and nerve distribution of 16 cases of atrial tachycardia originating from the atrioventricular cingulum or adjacent atrial muscle which were proved by electrophysiological monitoring and radiofrequency ablation.</p><p><b>RESULTS</b>Atrial tachycardia from peri-cingulum represented 23.2% of atrial tachycardia treated by radiofrequency ablation during the same period. The ratio of left to right atrioventricular cingulum was 3:16. There was no difference of the surface ECG characteristics and electrophysiological mechanism between the atrial tachycardia originating from atrioventricular cingulum and that from other positions. Both A and V components were recorded at all the successful ablation sites. The ratio of amplitude of A to V was between 2:3 and 6:1. Atrial potential in the target site was 20-46 (38.6 +/- 6.7) ms earlier than P'wave in surface ECG. The success rate of ablation was 87.5% and the recurrent rate 7.1%.</p><p><b>CONCLUSIONS</b>Peri-cingulum atrial tachycardia accounts for a certain proportion in all atrial tachycardia. The exciting sites originating from right cingulum are more common than those from left cingulum. Its electrophysiological mechanism has no difference from other positions. Cingulum mapping and ablation have important practical meanings.</p>