ABSTRACT
Arrhythmia-induced cardiomyopathy(AIC) is an reversible dilated cardiomyopathy and appears to occur at any age.The morbidity of AIC is unclear and likely underestimated.The pathophysiology and mechanism of AIC is unknown.It is often difficult to determine whether arrhythmias are the cause or result of cardiac dysfunction.The diagnosis of AIC can be only confirmed after recovery or improvement of cardiac function after elimination of the tachyarrhythmia.Tachycardias, ventricular premature contraction, left bundle branch block and ventricular preexcitation are known to trigger AIC.Appropriate diagnosis and treatment of AIC can reverse cardiac function.However, arrhythmia recurrence can lead to rapid recurrence of AIC and symptoms of heart failure.
ABSTRACT
Premature ventricular contraction is one of the most common arrhythmias in pediatric.Its incidence increases with age.The clinical symptoms of children's premature ventricular beats vary greatly,and the pediatric patients may have no discomforts,while the serious patients may have life-threatening events such as malignant ventricular arrhythmia and cardiac arrest.How to evaluate premature ventricular contraction and to guide the life and activities of children with premature ventricular contraction is of great significance.By adjusting the speed and slope of the plate,the motion of the subject is adjusted to increase the work and increase the heart rate,then the arrhythmia that is absent in the static state can be found or the original arrhythmia can be changed or disappeared.Treadmill test has been carried out in China for more than 30 years.Though some clinical experience has been accumulated,but there are still a lot of problems.This article reviews the present state and precision management of treadmill test's effect on children with ventricular premature contraction.
ABSTRACT
Objective To explore the relationship between heart rate variability (HRV) and deceleration capacity (DC) in children with idiopathic ventricular premature contraction of different origins. Methods The clinical data from 155 children with idiopathic ventricular premature contraction were retrospectively analyzed. According to the age, the children were divided into young children group (3 years old), preschool age group (3-6 years old) and school age group (6-16 years old). Each group was divided into the right ventricular type group and the left ventricular type group respectively according to the origin site. The differences of HRV and DC were compared among groups. Results Among three different age groups, the DC and time domain of HRV were signiifcantly different (P all?0 . 05 ). In young children group, RMSSD, HF, LF/HF, DC, and PNN 50 were statistically different between right ventricular type group and left ventricular type group (P all?0 . 05 ). In preschool age group, RMSSD, LF, HF, LF/HF, and DC were statistically different between right ventricular type group and left ventricular type group (P all?0 . 05 ). In school age group, the RMSSD, HF, LF/HF, and DC were statistically different between right ventricular type group and left ventricular type group (P all?0 . 05 ). Conclusions Children with idiopathic ventricular premature contraction have impaired regulations of cardiac autonomic system which mainly manifests as reduced tension of vagus nerve. Ventricular premature contraction originated from ventricle preponderance (young children and preschool children are right preponderance while school children are left preponderance) increases the risk of malignant arrhythmia.
ABSTRACT
BACKGROUND: Circadian rhythms have been described for acute myocardial infarction, sudden cardiac death, cerebrovascular disease, ischemic heart disease, and ventricular arrhythmia. Most of studies reported that the frequency of ventricular permature contractions(VPC's) shows a peak in day time. We tried to see that the circadian rhythm of VPC's in hypertension and ischemic heart disease(IHD) patients. And we will also studied the relationship between heart rate and frequencey of VPC's. METHOD: Twenty four hour holter monitoring was performed in hypertensive patients (N=23), ischemic heart disease patients(N=25), and normal control group(N=30). We tested the circadian pattern of VPC's and heart rates and the relationships of the frequency of VPC's and heart rates. RESULT: In hypertension group, a peak incidence of heart rate is between 5 and 8 P.M., in ischemic heart disease group, between 3 and 6 P.M.. In control group, the heart rate shows a peak beteen 1 and 3 P.M.. The frequency of VPC's in hypertension group shows the first peak between 4 and 10 P.M., and the second peak beteen 7 and 10 A.M.. In ischemic heart disease group, they show a peak between 2 and 8 P.M..In control group, there was no circadian variation for the frequency of VPC;s. Both in hypertension and IHD patients group, there was significant correlation between the frequency of VPC's and the heart rates. CONCLUSION: It seemed that VPC' were more frequently occurred in relation to the increase of heart rate in the afternoon, in hypertensive and ischemic heart disease patients.
Subject(s)
Humans , Arrhythmias, Cardiac , Circadian Rhythm , Death, Sudden, Cardiac , Electrocardiography, Ambulatory , Heart , Heart Rate , Hypertension , Incidence , Myocardial Infarction , Myocardial Ischemia , Ventricular Premature ComplexesABSTRACT
Treadmill exercise test and cold water face-immersion test were performed in 50 patients with tetralogy of Fallot at a mean age of 11.9 years, an average of 8.2 years after intracardiac repair. Cardiac catheterization was also performed in 45 patients 0.5-11 years after the repair.<BR>Exercise performance and results of catheterization were compared in patients with and without ventricular premature contraction (VPC) . In 22 (44%) of the 50 patients, VPC was induced by treadmill and/or cold water face-immersion test. Compared with the other 28 patients, the patients who had VPC during the tests, 1) were older (13.6 versus 10.6 years, p< 0.05, t-test) and were tested at a longer interval after repair of tetralogy of Fallot (9.5 versus 7.3 years, p<0.05), 2) showed no difference in the results of catheterization, and 3) had lower exercise performance.<BR>Cold water face-immersion test is therefore considered to be useful for evaluation of patients after intracardiac repair of tetralogy of Fallot.