R-R Interval Characteristic Of Ambulatory Electrocardiogram And Clinic Retrospective Research In Patients With Atrial Fibrillation

Objective: To study the characteristic, distribution, influent factor and prognosis of the R-R interval in atrial fibrillation(Af) through observing the ambulatory Electrocardiogram performance and clinic retrospective research of the R-R interval in patient with atrial fibrillation, supplying with theoretical basis to clinical therapy. Methods: Holter monitoring, clinical characteristics including demographer, fundamental heart diseases ,echocardiography characteristics, antiarrhythmic drugs and one year follow up data study was retrospectively performed in 296 hospitalized patients aged 24～92(mean 66.58±10.87) out of 309 case with Af at in-patient and out-patient department from 2000.12to 2002.12. The maximum, minimum RR interval and occurring time and the time and number of RR interval ≥1.5s, mean ventricular rates ,the time of longest and shortest RR interval were recorded respectively. Clinical influence factors to RR interval were compared between the group of RR ≥ 1.5s and <1.5s, RR ≥ 3.0s and RR<3.0s. Results: Among the 296 patients consists of 163(55.1%)male and 133(44.9)female with atrial fibrillation (mean66.58±10.87years ), there are 185(62.5%) patients with essential hypertension ,96(32.4%) with coronary artery disease,52(16.2%)with rheumatic heart disease,54(18.2%)with prior stroke ,and 48(15.5%) with diabetes mellitus. RR interval ≥1.5s in 217 cases( 64.23)were recorded during Holter monitoring.The number of RRinterval ≥ 1.5s was 106343 in 217 patients, among which 148(50%) patients had RR interval between 2.0and 3.0 seconds ,23 (7.77%)patients had RR interval ≥3.0s. The prevalence of long RR interval showed its peak between 23:00 and 5:00. There was no significant difference in general clinical characteristics between RR≥1.5s group(79 cases,26.7%) and RR<1.5s group(217 cases,73.3). Compared with patients with RR<1.5s, there were more patients taken digoxin in RR≥1.5s group (P=0.048). There was no significant difference in general clinical characteristics between RR≥3.0s group and RR<3.0s group. After 1 year follow-up, 18(6.1%) patients died in 296 cases with Af, 3 in RR<1.5s group,15 in RR interval between1.5s and 3.0s group , and none in RR≥3.0s group, There was no significant statistic difference between groups with and without long RR intervals. The first cause of death was congestive heart failure(10 patients,55.6%),followed by persistent Af. Multi-factor regression result showed that long RR intervals were mostly found in patients with persistent Af. Conclusions: Long RR interval in patients with atrial fibrillation is very common(64.23%).The prevalence is 64.23(217/296),and its distribution performs as circadian rhythm, occuring mostly between 23:00 and 5:00. Long RR intervals are not influenced by age, sex, Af time, foundermental heart disease, cardiac founction and the size of heart. Long Af interval can not be worthened by the application of metoprolol,amiodaron, diltiazem,moracizine, propafenone. Digoxin may lengthen RR interval. Long RR intervals during Af attack do not relate to the increase of death rate.