Noninvasive ambulatory blood pressure monitoring in 22 healthy normotensive young adolescents

BACKGROUND: Ambulatory blood pressure monitoring is widely available in clinical practice. To evaluate the pattern of normal 24 hour variation of blood pressure and the problems in analysis of data which was obtained with use of automatic blood pressure recorder, 24 hour ambulatory blood pressure was measured. METHODS: Ambulatory blood pressure was recorded for 24 hours with automatic blood pressure monitor in 22 normotensive young adolescents. RESULTS: 1) Average 24-hour BP was 109mmHg in systolic(115+/-30 for male, 102+/-30 for female), 66mmHg in diastolic(69+/-18 for male, 63+/-19 for female) and pulse rate was 72 beats per minute(70+/-23 for male, 75+/-26 for female). 2) Data obtained from ambulatory blood pressure monitor should be analyzed after deletion of unacceptable data with use of conventional criteria. Blood pressure increase which is not accompanied by increase in pulse rate increase can be used as another criteria to rule out unacceptable blood pressure data. 3) Blood pressure was low from mid-night to 6 A.M. and began to rise slowly till mid-day and then maintained steadily through the remainder of the day. And 24 hour variation of blood pressure was more adequately assessed after application of Fourier analysis. CONCLUSIONS: These results suggest that certain deletion criteria was inevitable during analysis of the data which were obtained from ambulatory blood pressure recorder and Fourier analysis can be used as valuable smoothing technique to assess the 24-hour blood pressure profiles.

The significance of the morphology of ventricular premature complex(VPC) as a marker for left ventricular structure and function

BACKGROUND: There has been reports which suggest that the morphologic feature of ventricular premature complex(VPC) might reflect the cardiac state. METHODS: To test this, we studied retrospectively the association between the morphologic feature of VPC(shape and duration) and cardiac state(structural and functional) by analysing the records of ECG(179 cases) obtained from reviewing echocardiogram performed in our hospital from 1988 to early 1991. Group 1(n=84) had VPC-QRS complexes with either smooth and uniterruped contour or narrow( or =0.04 sec) notching or shelves. Without taking into account of either the presence of the type of the underlying cardiac disease and other constitutional disease state, we classified the type of VPC on ECG according to the above criteria and analysed its simple association with cardiac size and functional state on echocardiogram. RESULTS: In group 1, 68 of 84 cases with a VPC had no notching. In group 2, the VPC-QRS duration was greater than group 1(0.154+/-0.022 vs 0.141+/-0.011 sec(mean+/-S.D.), p=0.0001).Left ventricular end-diastolic diameter(LVED) and ejection fraction(EF) showed a significant difference between the two groups(5.12+/-0.64 vs 5.72+/-0.95cm, p=0.0003 and 65.89+/-10.84 vs 60.82+/-15.5%, p=0.012 respectively). In group 2, 50 of 95 cases(53%) showed ejection fraction less than 64%. By defining left ventricular structural dilatation and functional impairment on echocardiogram as LEVD greater than 5.5cm and EF less than 64% respectively, the sensitivity and specificity of VPC morphology was 60% and 74% respectively. CONCLUSIONS: We conclude that a broadly(> or =0.04 sec) notched VPC of long duration(> or =0.15 sec) is a simple and reliable 12-lead ECG marker for an abnormal structural and functional state of the heart(dilatation and hypokinetic left ventricle), irrespective to underlying cardiac disease, while a VPC with smooth contour or narrow(<0.04 sec) notching with short duration(<0.15 sec) reflects a normal sized heart with normal systolic function.