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- Bukachi, Frederick, et al.
(författare)
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Age dependency in the timing of mitral annular motion in relation to ventricular filling in healthy subjects : Umea General Population Heart Study
- 2008
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Ingår i: European Journal of Echocardiography. - : Oxford University Press (OUP). - 1525-2167 .- 1532-2114. ; 9:4, s. 522-529
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Peak left ventricular (LV) relaxation normally precedes peak filling (E), which supports the hypothesis that LV suction contributes to early-diastolic filling. The significance of similar temporal discordance in late diastole has previously not been studied. We describe the time relationships between mitral annular motion and LV filling in early and late diastole and examine the effect of normal ageing on these time intervals. METHODS AND RESULTS: A total of 128 healthy subjects aged 25-88 years were studied. Transmitral and pulmonary venous flow reversals (Ar) were recorded by Doppler echocardiography. Mitral annular diastolic displacement-early (E(m)) and late (A(m))-were recorded by Doppler tissue imaging. With reference to electrocardiographic R and P-waves, the following measurements were made: R to peak E-wave (R-E) and E(m) (R-E(m)); onset P to peak A-wave (P-pA), A(m) (P-pA(m)), and Ar (P-pAr). The differences between [(R-E) and (R-E(m))] for early-diastolic temporal discordance (EDTD) and [(P-A) and (P-A(m))] for late-diastolic temporal discordance (LDTD) were calculated. Isovolumic relaxation time (IVRT) was also measured. Early-diastolic temporal discordance was approximately 26 ms in all age groups. Late-diastolic temporal discordance, however, was inversely related to age (r = -0.35, P < 0.001) and IVRT (r = -0.34, P < 0.001) and therefore decreased in the elderly vs. young (13 +/- 10 vs. 23 +/- 10 ms; P < 0.001). In multivariate analysis, age failed to predict LDTD in the presence of IVRT. A, A(m), and Ar were simultaneous at onset, and peak A(m) coincided with peak Ar in all age groups (r = 0.97, P < 0.001). No significant differences were noted in the RR intervals. CONCLUSIONS: Sequential prolongation of IVRT with ageing reduces LDTD, thus converging the peaks of A(m), A, and Ar (atrial mechanical alignment)-a potential novel method to identify subjects at increased dependency on atrial contraction for late-diastolic filling.
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| 2. |
- Bukachi, Frederick, et al.
(författare)
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Clinical outcome of coronary angioplasty in patients with ischaemic cardiomyopathy
- 2003
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Ingår i: International Journal of Cardiology. - 0167-5273 .- 1874-1754. ; 88:2-3, s. 167-174
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess the clinical outcome of successful percutaneous transluminal coronary angioplasty (PTCA) in patients with poor ventricular function. METHODS: Analysis of angiographic, echocardiographic and clinical records of patients with severe LV dysfunction who underwent PTCA from January 1, 1995 to December 31, 1997 was undertaken. Forty-one patients aged 63+/-10 years, 36 men, all with significant coronary artery disease and impaired LV function (fractional shortening, FS
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| 3. |
- Bukachi, Frederick, 1960-
(författare)
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Ventricular Long Axis Function: Amplitudes and Timings : Echocardiographic Studies in Health and Disease
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The ageing process not only increases the risk of coronary artery disease (CAD) but also complicates its diagnosis and treatment. It is therefore important to understand the newer concepts of cardiovascular ageing physiology as well as methods of predicting the outcomes of therapeutic options available for the elderly with severe CAD. Studies of atrioventricular (AV) ring or plane motion have attracted considerable interest in the last few years as a means of assessing ventricular and atrial function. As the displacement of AV rings towards the ventricular apex is a direct reflection of longitudinal fibre contraction, its measurement by echocardiography provides additional information regarding global and regional systolic and diastolic function. Left ventricular (LV) long axis amplitude of motion, referred to as mitral valve annular (MA) motion, is reduced in CAD and to some extent in the elderly as part of the normal ageing process. Objectives & Methods: The aim of the present study was two-fold. First, to investigate the relationship between the timing of MA motion and transmitral and pulmonary venous flow in healthy subjects, and to define the physiological significance of that relationship including its potential diagnostic utility. Second, to investigate the relationship between the clinical outcome and the behaviour of long axis function in patients with severe ischaemic LV dysfunction (SLVD) after percutaneous coronary angioplasty (PTCA). Transmitral early (E) and late (A) filling, and pulmonary venous flow reversal (Ar) were studied by Doppler echocardiography, while at the left lateral AV ring, the MA motion in early (Em) and late (Am) diastole were recorded by Doppler tissue imaging (DTI) and M-mode echocardiography. Results: Healthy subjects – In early diastole the onsets of LV filling (E) and relaxation (Em) were simultaneous, and peak Em preceded peak E by 26 msec in all age groups, constituting a time interval referred to as early diastolic temporal discordance (EDTD). Similarly, the onsets of Am, A and Ar were simultaneous at onset and began approximately 84 msec after the electrocardiographic P wave. Peak Am preceded peak A by 23 msec in the young and by 13 msec in the elderly, a time interval referred to as late diastolic temporal discordance (LDTD). Peak Ar, on the other hand, coincided with peak Am in all age groups. With increasing age and sequential prolongation of isovolumic relaxation time, the peaks of Am, Ar and A converged. This point of convergence is described as atrial mechanical alignment (AMA). Patients – MA total amplitude of motion, rates of shortening and lengthening were all reduced in patients with SLVD. At mid-term, 3-6 months after PTCA, there was improvement in all these variables. A pre-procedure long axis cut off value of ≥5 mm was associated with favourable symptomatic outcome. Overall angiographic success was 95.2%, and event-free survival was 78.4% at one month and declined steadily to 62.3% at one year with 2.5% mortality. Conclusions: EDTD, which reflects ventricular restoring forces (suction) is age independent while the narrowing of LDTD leading to AMA provides a novel method to identify healthy subjects at increased dependency on left atrial contraction for late diastolic filling. Peak atrial contraction (Am) coincides with peak Ar, thus the timing of regional atrial contraction by DTI can be used to estimate corresponding measurements of Ar, which is often difficult to image by transthoracic echocardiography. In patients with SLVD long axis total amplitude of at least 5 mm at the left MA suggests a significant potential for segmental function recovery after PTCA. Keywords: Echocardiography, Doppler tissue imaging, ageing, coronary disease, left ventricular dysfunction, atrial contraction, electromechanical function, coronary angioplasty.
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