Effect Of Frequent Premature Ventricular Contraction In Middle-Low Frequency Right Ventricular Out Flow Tract On Left Ventricular Diastolic Function And Clinical Significance Of Early In Tervention

Objective: To investigate the effect of frequent premature ventricular contraction in the middle and low frequency right ventricular outflow tract(RVOT)on left ventricular diastolic function and the clinical significance of early intervention.Methods: The patients were enrolled at the Heart Center of Zhongshan Hospital affiliated to Dalian University from September 2016 to December 2018 and the 12-lead ECG judges the patients who originate from the right ventricular outflow tract(RVOT)and have 1000≤PVC number/24 hours<20000 and the age less than or equal to 75 years old.The following conditions were excluded: 1)organic heart disease;2)long-term or regular use of antiarrhythmic drugs;3)patients with a history of heart-related surgery such as bypass surgery and radio frequency catheter ablation also valve replacement;4)diabetes and hypertension;5)abnormal liver and kidney functions;6)history of malignant tumors.116 eligible patients were divided into three groups according to the number of frequent premature ventricular contraction every 24 hours.There were 36 cases in control group(1000≤PVC number/24 hours<5000),40 cases in low frequency group(5000≤PVC number/24 hours<10000)and 40 cases in intermediate frequency group(10000≤PVC number/24 hours<20000).The control group was given placebo treatment and the low frequency group was given beta-blockers(100mg/day)orally.The intermediate frequency group was divided into drug treatment group(beta-blockers 100mg/day)20 cases and radio frequency catheter ablation group(20 cases),followed up for half a year.The results of24-hour ambulatory electrocardiogram,ultrasonocardiogram and SF-36 quality of life score before and after treatment were recorded.SPSS 20.0 was used for statistical analysis.Results: 1.Age,gender,duration of symptoms,width of QRS,coupling interval,short ventricular tachycardia,early insertion,standard deviation of all normal to normal RR intervals,retrograde P-wave and bad habits(smoking,drinking and staying up late)were not statistically different between the three groups(p>0.05).2.There was no difference in LAD,LVDD,LVEF,E/A,mitral E velocity,mitral A velocity,average heart rate and the quality of life among the three groups before treatment.E/Ea in middle group was higher than that in control group(8.72±2.28 vs 9.77 ±2.14 vs10.10 ±2.31,p<0.05).3.There was no difference in LAD,LVDD,E/Ea,LVEF,E/A,mitral E velocity,mitral A velocity and the quality of life among the control group and the low frequency group before and after treatment,but the low frequency group decreased the number of PVC every 24 hours,slowed down the average heart rate(p<0.05).There was no difference in LAD,LVDD,E/Ea,LVEF,E/A,mitral A velocity and quality of life between the middle frequency group and the low frequency group before and after treatment,but the low frequency group decreased the number of PVC every 24 hours,slowed down average heart rate.The average heart rate and the number of LAD,E/Ea,the number of PVC every 24 hours and the quality of life were improved in RFCA group(p<0.05).4.After treatment,the number of PVC every 24 hours in the low frequency group was lower than that in the control group and the middle frequency group(p<0.05).5.Radio frequency catheter ablation was superior to drug therapy in improving E/Ea,the number of PVC every 24 hours and general health(p<0.05);drug therapy was superior to radio frequency catheter ablation in improving mitral A velocity and average heart rate(p<0.05).Conclusion: The number of frequent premature ventricular contraction every 24 hours from 10000 to 20000 in right ventricular outflow tract may lead to left ventricular diastolic dysfunction.After six months of placebo treatment,the number of frequent premature ventricular events increased.Oral beta-blockers could reduce the number of frequent premature ventricles.The placebo treatment and drug treatment can not improve left ventricular diastolic function and quality of life.Radio frequency catheter ablation can reduce the number of frequent premature ventricular contraction events,improve left ventricular diastolic function and improve the quality of life.Radio frequency catheter ablation can significantly reduce the number of PVC compared with oral drug therapy.