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Objective: To investigate the long-term efficacy and safety of left cardiac sympathetic denervation(LCSD) for long QT syndrome(LQTS) patients with either recurrence on drug therapy intolerance/refusal. Methods: This study was a retrospective cohort study. The cases selected from 193 patients with LQTS who were enrolled in the Chinese Channelopathy Registry Study from November 1999 to November 2012. This study selected 28 LQTS patients with either recurrence on drug therapy intolerance/refusal and underwent LCSD surgery in the Peking University People's Hospital or Beijing Tongren Hospital. The patients were allocated into 3 groups: high-risk group(n=13, baseline QTc ≥550 ms or symptomatic in the first year of life or highly malignant genetics); intermediate-risk group(n=10, 500 ms≤baseline QTc<550 ms, symptomatic after the first year and without highly malignant genetics); low-risk group(n=5, baseline QTc<500 ms, symptomatic after the first year and without highly malignant genetics). LCSD was performed with the traditional supraclavicular approach or video assisted thoracoscopic surgery (VATS). Patients were regularly followed up until 20 years after the surgery. Data were collected before and 1 year after surgery and at the last follow-up. Patients' electrocardiograph(ECG), cardiac events and surgery-related complications were recorded. Kaplan-Meier survival analysis was used to determine the cardiac event-free survival based on different risk stratification and genotypes. Results: A total of 28 LQTS patients, aged 20.5 (15.0, 37.5) and underwent LCSD surgery, were enrolled in this study, including 23(82.1%) women. There were 11(39.3%) patients treated with traditional approach while 17(60.7%) with VATS-LCSD. There were 19(67.9%) patients had positive genetic test results, including 4 LQT1, 12 LQT2, 1 LQT1/LQT2 mixed type, and 2 Jervell-Lange-Nielsen (JLN) syndrome. The median follow-up period was 189.3(138.7, 204.9) months. The dropout rate was 10.7%(3/28) while 3 patients in the intermediate-risk group were lost to follow-up. Horner syndrome occurred in 1 patient (in the high-risk group). Sudden cardiac deaths were observed in 3 (12.0%) patients (all in the high-risk group), and 12 patients (48.0%) had syncope recurrences (2 in low-risk group, 3 in intermediate-risk group and 7 in high-risk group). A significant reduction in the mean yearly episodes of cardiac events was observed, from (3.5±3.3) before LCSD to(0.2±0.1) at one year after LCSD and (0.5±0.8) at last follow up(P<0.001). The mean QTc was shortened from (545.7±51.2)ms before the surgery to (489.0±40.1)ms at the last follow-up (P<0.001). Among the 20 patients with basic QTc ≥500 ms and completing the follow-up, the QTc intervals of 11(55.0%) patients were shortened to below 500 ms. The event free survival rates for any cardiac events after LCSD decreased sequentially in the low-, intermediate- and high-risk groups, and the difference was statistically significant (χ²=7.24, log-rank P=0.026). No difference was found in the event free survival rates among LQT1, LQT2 and undefined gene patients (χ²=5.20, log-rank P>0.05). Conclusions: LCSD surgery can reduce the incidence of cardiac events and shorten the QTc interval in patients with LQTS after the long-term follow-up. LCSD surgery is effective and safe for patients with LQTS ineffective or intolerant to drug therapy. However, high-risk patients are still at a high risk of sudden death after surgery and should be actively monitored and protected by combined therapies.
Subject(s)
Female , Humans , Male , Electrocardiography , Heart , Long QT Syndrome , Retrospective Studies , Sympathectomy/methodsABSTRACT
2018 Expert Consensus for Diagnosis and Management of Syncope in China includes the classification,pathophysiology, initial evaluation, risk stratification, Dauxiliary examinations, diagnosis, treatment and characteristics of syncope in special population. It represents the latest concept of diagnosis and treatment of syncope. It is simple and practical, and is helpful for clinicians to deal with patients with syncope and even transient loss of consciousness.
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<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>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Coronary Disease , Outpatients , Smoking Cessation , MethodsABSTRACT
<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>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Acute Coronary Syndrome , Epidemiology , Arrhythmias, Cardiac , Epidemiology , China , Epidemiology , Risk FactorsABSTRACT
<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>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Blood Pressure , Physiology , Case-Control Studies , Heart Rate , Physiology , Tobacco Smoke PollutionABSTRACT
<p><b>OBJECTIVE</b>To prospectively evaluate the change of quality of life in patients with acute coronary syndrome following percutaneous coronary intervention (PCI) with drug-eluting stents and explore the influencing factors of quality of life.</p><p><b>METHODS</b>There hundred and thirty four consecutive patients with acute coronary syndrome receiving drug-eluting stents implantation between September 2008 and December 2009 were enrolled. Of them, two hundred and ninety three patients completed 36-item short form health survey at baseline and 6 months after PCI procedure. Change of quality of life and influencing factors on quality of life were analyzed.</p><p><b>RESULTS</b>Compared with baseline, quality of life improved significantly after PCI in terms of both physical component summary and mental component summary [ (51.07 ± 20.39) scores vs. (61.69 ± 19.73) scores and (63.27 ± 20.00) scores vs. (68.81 ± 18.71) scores, respectively; all P < 0.01]. Multiple linear regression analysis showed that female, diabetes and ST-segment elevation myocardial infarction were independent predictors of physical component summary improvements post PCI (β values were -0.310, -3.880 and 1.302, respectively; P < 0.05 or P < 0.01). Previous PCI and diabetes were independent predictors of mental component summary improvements post PCI (β values were -1.483 and -2.790, respectively; all P < 0.01).</p><p><b>CONCLUSIONS</b>Quality of life of acute coronary syndrome patients is significantly improved at 6 months after drug-eluting stents implantation. The predictors of physical quality of life improvement are female, diabetes, and ST-segment elevation myocardial infarction. Predictors of mental quality of life improvement are previous PCI and diabetes.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Acute Coronary Syndrome , General Surgery , China , Drug-Eluting Stents , Quality of Life , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to observe the association between inflammation status/autoimmune antibodies and plasma lipid in patients with rheumatoid arthritis (RA).</p><p><b>METHODS</b>A total of 402 RA patients were admitted into our hospital during January 2008 to March 2009 and 225 RA patients who met the inclusion criteria were selected to perform a full lipid profile examination including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), anti-keratin antibody (AKA), anti-perinuclear factor autoantibody (APF) and complement (C) were also evaluated. Atherogenic index of plasma (AIP) was calculate by the formula Log (TG/HDL-C).</p><p><b>RESULTS</b>(1) There were 12.9%, 10.2% and 14.2% patients with elevated TC, LDL-C and TC respectively, patients with reduced HDL-C accounted for 43.6%. (2) C(3) was higher in elevated TC group than normal TC group (P < 0.05). ESR and CRP were significantly higher in decreased HDL-C group than in normal HDL-C group (P < 0.05). CRP, C(3) and C(4) were significantly higher in elevated LDL-C group than in normal LDL-C group (P < 0.05). (3) Multiple stepwise regression analysis showed that C(3) was positively correlated with TC (R(2) = 0.067, P < 0.05). Both ESR and CRP were negative correlated with HDL-C (R(2) = 0.202, P < 0.05). CRP and anti-CCP were positively correlated with LDL-C (R(2) = 0.129, P < 0.05). ESR and C(4) were positively correlated with AIP (R(2) = 0.046, P < 0.05).</p><p><b>CONCLUSION</b>This study showed that rheumatoid arthritis is associated with an abnormal lipid profile, especially in patients with increased inflammation markers and autoimmune antibodies. Moreover, ESR and C(4) were predictors of increased AIP in this cohort.</p>
Subject(s)
Aged , Humans , Arthritis, Rheumatoid , Blood , Allergy and Immunology , Autoantibodies , Blood , Autoimmunity , C-Reactive Protein , Cholesterol, HDL , Blood , Cholesterol, LDL , Blood , Complement System Proteins , Inflammation , Lipids , Blood , Lipoproteins, HDL , Blood , Triglycerides , BloodABSTRACT
<p><b>OBJECTIVE</b>To screen the cardiac troponin T (TNNT2) mutations in Chinese patients with hypertrophic cardiomyopathy (HCM) and to analyze the potential link between the genotype and the phenotype.</p><p><b>METHODS</b>Clinical features of 100 probands with HCM and some family members were evaluated, 200 unrelated normal subjects served as control. The exons and flanking introns of TNNT2 were amplified with PCR and direct sequencing was used to screen TNNT2 mutations/polymorphisms.</p><p><b>RESULTS</b>Two novel missense mutations were detected in 2 HCM patients: R92W and R286H. These 2 mutations were not found in 200 non-HCM controls. A five-basepair insertion/deletion polymorphism in intron 3 of TNNT2 was identified in this HCM cohort but was not related to the phenotype.</p><p><b>CONCLUSIONS</b>Two missense mutations, R92W and R286H, were found in 2/100 patients with HCM, TNNT 2 mutation is relatively low in Chinese patients with HCM.</p>
Subject(s)
Humans , Asian People , Cardiomyopathy, Hypertrophic , Genetics , Case-Control Studies , Exons , Genotype , Mutation , Mutation, Missense , Pedigree , Phenotype , Polymorphism, Genetic , Troponin T , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To screen the MYBPC3 gene mutations in Han Chinese patients with hypertrophic cardiomyopathy (HCM).</p><p><b>METHODS</b>Sixty-six patients with HCM were enrolled for the study. The exons in the functional regions of MYBPC3 were amplified with PCR and the products were sequenced.</p><p><b>RESULTS</b>Four novel mutations and four common polymorphisms were identified in this patient cohort. A Lys301fs mutation in exon10 was evidenced in a H30, and when he was 47 years old, he had the chest tightness, shortness of breath with septal hypertrophy of 18.7mm; a Asp463stop mutation in exon17 was detected in a H48, he was 24 years old 24-year-old when a medical examination showed ventricular septal hypertrophy of 15.4 mm; both Gly523Arg mutation in exon18 and Tyr847His mutation in exon26 were found in a H53 with onset age 36 years old, feeling chest tightness after excise and his ventricular septal hypertrophy was 27 mm that time. MYBPC3 mutations occurred in 4.5% patients in this cohort. These mutations were not found in 100 non-HCM control patients.</p><p><b>CONCLUSION</b>MYBPC3 mutation is presented in a small portion of Han Chinese patients with HCM.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Asian People , Genetics , Cardiomyopathy, Hypertrophic , Genetics , Carrier Proteins , Genetics , DNA Mutational Analysis , Exons , Genotype , Mutation , Phenotype , RNA, Messenger , GeneticsABSTRACT
<p><b>OBJECTIVE</b>Brugada syndrome is an inherited channelopathy that characterized by ST-segment elevation in the right precordial lead (V(1)-V(3)) on the electrocardiogram with or without right bundle branch block and related with high risk of sudden cardiac death and structurally normal hearts. The first and only gene linked to this disease is SCN5A, a gene encodes for alpha subunit of the cardiac sodium channel. The objective of this study is to explore SCN5A gene mutations in Chinese patients with Brugada syndrome.</p><p><b>METHODS</b>Four patients diagnosed as Brugada syndrome and nine patients with suspected Brugada syndrome were chosen for the study. The exons in the functional regions of SCN5A gene were amplified with polymerase chain reaction and the amplified products were sequenced with Sanger method. If a mutation was identified, patient's family members were also screened.</p><p><b>RESULTS</b>Two heterozygous mutations were found in one family diagnosed as Brugada syndrome. One missense mutation was a G-->A transition in the first nucleotide of codon 95 in SCN5A gene exon 3, which was predicted to result in substitution of Valine with Isoleucine (V95I). The other missense mutation was a C-->T transition in the second nucleotide of codon 1649 in SCN5A gene exon 28, which was predicted to result in substitution of Alanine with Valine (A1649V). A heterozygous mutation was identified in one family suspected to have the disease. The mutation was a three nucleotides (TCT) deletion that caused Phenylalanine deletion in codon 1617 in SCN5A gene exon 28. The three mutations were not detected in 100 control chromosomes.</p><p><b>CONCLUSIONS</b>Mutation in SCN5A gene is one of the causes of Brugada syndrome in Chinese. Three novel SCN5A gene mutations were identified in Chinese with Brugada syndrome, which expands the spectrum of SCN5A mutations associated with the disease.</p>
Subject(s)
Adolescent , Adult , Aged , Humans , Male , Middle Aged , Brugada Syndrome , Genetics , Case-Control Studies , Exons , Genetics , Muscle Proteins , Genetics , Mutation , Sodium Channels , GeneticsABSTRACT
<p><b>OBJECTIVE</b>The aim of this study was to screen the disease-causing gene mutations and investigate the genotype-phenotype correlation in 10 Chinese pedigrees with familial hypertrophic cardiomyopathy (HCM).</p><p><b>METHODS</b>There are 91 family members from these 10 pedigrees and 5 members were normal mutated carriers, 23 members were HCM patients (14 male) aged from 1.5 to 73 years old. The functional regions of myosin heavy chain gene (MYH7), cardiac myosin-binding protein C (MYBPC3) and cardiac troponin T gene (TNNT2) were screened with PCR and direct sequencing technique. Clinical information from all patients was also evaluated in regard to the genotype.</p><p><b>RESULTS</b>Mutations were found in 5 out of 10 pedigrees. Mutations in MYH7 (Arg663His, Glu924Lys and Ile736Thr) were found in 3 pedigrees and 3 patients from these pedigrees suffered sudden death at age 20-48 years old during sport. Mutations in MYBPC3 were found in 2 pedigrees, 1 with complex mutation (Arg502Trp and splicing mutation IVS27 + 12C > T) and 1 with novel frame shift mutation (Gly347fs) and the latter pedigree has sudden death history. No mutation was identified in TNNT2.</p><p><b>CONCLUSIONS</b>Although the Han Chinese is a relatively homogeneous ethnic group, different HCM gene mutations were responsible for familiar HCM suggesting the heterogeneity nature of the disease-causing genes and HCM MYH7 mutations are associated with a higher risk of sudden death in this cohort. Furthermore, identical mutation might result in different phenotypes suggesting that multiple factors might be involved in the pathogenesis of familiar HCM.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , Asian People , Genetics , Cardiac Myosins , Genetics , Cardiomyopathy, Hypertrophic, Familial , Ethnology , Genetics , Carrier Proteins , Genetics , Mutation , Myosin Heavy Chains , Genetics , Pedigree , Phenotype , Troponin T , GeneticsABSTRACT
<p><b>OBJECTIVE</b>Jervell and Lange-Nielsen syndrome (JLNS) is a severe cardioauditory syndrome manifested as QT interval prolongation, abnormal T waves, and relative bradycardia ventricular tachyarrhythmias. In this report, we screened a nonconsanguineous families with JLNS for mutations in KCNQ1.</p><p><b>METHODS</b>Mutation analysis was performed by using purified PCR products to direct sequence analysis on an ABI-3730XL automated DNA sequencer. The whole sequence of proband' KCNQ1 was screened firstly, then screened the mutation exon sequences of others of the family and 50 unrelated normal persons.</p><p><b>RESULTS</b>A heterogeneous mutation was identified in the patients of the JLNS family, a missense mutation (G-->T) at nucleotide 917 encoded in exon 6 of KCNQ1. This substitution leads to a change from glycine to Valine at codon 306(G306V) corresponding to the S5 transmembrane segment of KCNQ1. The other normal members of the family and 50 unrelated normal persons were not identified this mutation.</p><p><b>CONCLUSION</b>The result suggested that not only homozygous mutations or compound heterozygous mutations in KCNQ1 could cause Jervell-Lange-Nielsen syndrome, the single heterozygous mutation may also cause Jervell-Lange-Nielsen syndrome.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Young Adult , Genotype , Jervell-Lange Nielsen Syndrome , Genetics , KCNQ1 Potassium Channel , Genetics , Long QT Syndrome , Genetics , Mutation, Missense , PedigreeABSTRACT
<p><b>OBJECTIVE</b>To search for the mutations of potassium voltage-gated channel, KQT-like subfamily member 1(KCNQ1) gene in 31 Chinese long QT syndrome(LQTS) families.</p><p><b>METHODS</b>Due to the genetic heterogeneity, the genotype of patients was first predicted based on the spectrum of ST-T-wave patterns on ECG. Ten of 31 probands were considered as LQT1. Then the mutation of KCNQ1 gene was screened by the polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) technique combined with DNA sequencing in all members of these 10 families. To avoid omitting some LQT1 patients without typical characteristics and also to do methodological comparison, the mutations of KCNQ1 gene on 16 exons were screened by PCR and direct DNA sequencing in the rest 21 non-LQT1 probands only. Co-segregation analysis was carried out after the finding of an abnormal sequence. In case that the abnormality existed in patients only, the test of such exon was performed in 50 irrelevant normal individuals.</p><p><b>RESULTS</b>Two missense mutations and three single nucleotide polymorphisms (SNPs) were found in the LQT1 predicted families. The two mutations were S277L (1 family) and G306V (1 family) in exon 5 and were not reported previously. Three polymorphisms were 435C-->T (7 families), 1632C-->A (1 family), and IVS1+9 C-->G (3 families). Only a splice mutation IVS1+5G-->A (2 families) and a polymorphism IVS10+18C-->T (1 family) were found in the non-LQT1 predicted probands. All three mutations were localized within the functional domain of KCNQ1 and were co-segregated with the disease, and were not found in 50 normal individuals.</p><p><b>CONCLUSION</b>Two novel missense mutations, 1 splice mutation and four SNPs on KCNQ1 gene were found in the 31 LQTS families. Combined with ECG-based genotype prediction, PCR-SSCP could find most mutations on KCNQ1 and be a simple and economic method for screening LQTS.</p>