PubMed · 9413497
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J B Chambers, H M Rimington. 1997-12-13. Constrictive pericarditis and tuberculosis.. https://doi.org/10.1016/s0140-6736(05)63617-3
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
AIM: To elucidate stability of 0.1 Hz component of heart rate variability (HRV) spectrum in patients with different state of myocardial contractile function during bicycle exercise tests under controlled breathing with 10 sec period. MATERIAL: Male patients with class II-III effort angina and either abnormal myocardial contractile function (n=45, age 51.0+/-2.5 years, left ventricular ejection fraction <50%), or without disturbances of myocardial contractility (n=35, age 52+/-6 years, ejection fraction > 60%). METHODS: All patients underwent Doppler echocardiography and submaximal exercise tests with initial loads 25 W. Registration of series of RR-intervals was done during controlled breathing with 10 sec periods (0.1 Hz) for 5 min at rest and exercise (25 W work load). Depth and balance of phases of controlled breathing were similar to those of spontaneous breathing. Analysis of the heart rate variability was made on the basis of auto-regression algorithm. RESULTS: Stability of 0.1 Hz component of the heart rate variability spectrum to low-level exercise correlated with the severity of depression of myocardial contractility.
OBJECTIVES: The isovolumetric relaxation time of the right ventricle (RV-IVRT) can be assessed using a method based on ECG and pulsed wave Doppler (PW). Recently pulsed wave Doppler tissue imaging (PW-DTI) has been introduced in the assessment. DESIGN: RV-IVRT obtained by the two methods was compared in 20 consecutive patients as was the time from the R wave on the ECG to the onset of tricuspid flow (R-T), to the closure of the pulmonic valve (R-P), to the onset of early diastolic motion of the tricuspid annulus tissue (R-E) and to the end of the systolic motion (R-S). RESULTS: RV-IVRT obtained by the PW method was significantly (p < 0.001) shorter than RV-IVRT obtained by PW-DTI. R-S had significantly (p < 0.001) shorter duration than R-P, while there was no significant difference between R-E and R-T. CONCLUSIONS: The methods are not measuring the same interval. Only the PW method measures RV-IVRT according to the usual definition. Different reference values have to be used if the methods are used in the assessment of RV diastolic function.
OBJECTIVE: To assess the long axis function of both ventricles during the early neonatal period by using pulsed wave Doppler tissue (PWDT) echocardiography. DESIGN: PWDT echocardiography was recorded from the lateral sites of the mitral and tricuspid annuluses and the tip of interventricular septum in 130 neonates within 24 hours after birth (day 0 group), in 135 neonates 1-7 days after birth (day 1-7 group), and in 131 healthy children (children group). RESULTS: Peak systolic motion velocity (Sw) of the three ventricular walls positively correlated with the number of days after birth (p < 0.005). Compared with the children group, in neonates Sw in the right ventricle and peak early diastolic motion velocity (Ew) and peak atrial systolic motion velocity in the interventricular septum were lower than in the remaining two walls (p < 0.0005, p < 0.0001, and p< 0.0001, respectively). Although peak mitral and tricuspid flow velocities during early diastole (E) correlated with the number of hours after birth in the day 0 group, there was no significant change in the Ew of either ventricle. The E:Ew ratio of both ventricles was significantly higher in both neonate groups than in the children group (p < 0.001). The E:Ew ratio of the left ventricle was higher in the day 0 group than in the day 1-7 group (p < 0.005). CONCLUSIONS: The two ventricles differ in their normal PWDT echocardiographic values and in the parameter change after birth during the early neonatal period, which may reflect differences in ventricular adaptation after birth.