Delayed onset of tricuspid valve flow in repaired tetralogy of Fallot: an additional mechanism of diastolic dysfunction and interventricular dyssynchronyReport as inadecuate




Delayed onset of tricuspid valve flow in repaired tetralogy of Fallot: an additional mechanism of diastolic dysfunction and interventricular dyssynchrony - Download this document for free, or read online. Document in PDF available to download.

Journal of Cardiovascular Magnetic Resonance

, 13:43

First Online: 24 August 2011Received: 04 March 2011Accepted: 24 August 2011

Abstract

BackgroundDiastolic dysfunction of the right ventricle RV is common after repair of tetralogy of Fallot. While restrictive physiology in late diastole has been well known, dysfunction in early diastole has not been described. The present study sought to assess the prevalence and mechanism of early diastolic dysfunction of the RV defined as delayed onset of the tricuspid valve TV flow after TOF repair.

MethodsThe study population consisted of 31 children with repaired TOF mean age ± SD, 12.3 ± 4.1 years who underwent postoperative cardiovascular magnetic resonance CMR. The CMR protocol included simultaneous phase-contrast velocity mapping of the atrioventricular valves, which enabled direct comparison of the timing and patterns of tricuspid TV and mitral MV valve flow. The TV flow was defined to have delayed onset when its onset was > 20 ms later than the onset of the MV flow. The TV and MV flow from 14 normal children was used for comparison. The CMR results were correlated with the findings on echocardiography and electrocardiography.

ResultDelayed onset of the TV flow was observed in 16-31 patients and in none of the controls. The mean delay time was 64.81 ± 27.07 ms 8.7 ± 3.2% of R-R interval. The delay time correlated with the differences in duration of the TV and MV flow 55.94 ± 32.88 ms r = 0.90, p < 0.001. Delayed onset was associated with prolongation of the RV ejection time in 9 and delayed onset and cessation of the pulmonary arterial flow in 4. Delayed onset was not associated with timing changes in the pulmonary artery in 3. The patients with delayed onset showed reduced RV ejection fraction p = 0.01. However, the two groups did not show significant differences in TV E-A ratio, ventricular end-diastolic volumes, left ventricular ejection fraction, pulmonary regurgitant fraction, heart rate, PR interval and QRS duration.

ConclusionsEarly diastolic dysfunction with delayed onset of TV flow is common after TOF repair, and is associated with reduced RV ejection fraction. It is a further manifestation of interventricular dyssynchrony and represent an additional mechanism of ventricular diastolic dysfunction.

Keywordstetralogy of Fallot delayed onset of tricuspid valve flow phase-contrast magnetic resonance right ventricular function diastolic dysfunction List of AbbreviationsCMRcardiovascular magnetic resonance

IVRTisovolumetric relaxation time

MPImyocardial performance index

MVmitral valve

PCphase-contrast

PApulmonary artery

RVright ventricle

TOFtetralogy of Fallot

TVtricuspid valve

Electronic supplementary materialThe online version of this article doi:10.1186-1532-429X-13-43 contains supplementary material, which is available to authorized users.

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Author: Ai-Min Sun - Fahad AlHabshan - Michael Cheung - Gabriele Bronzetti - Andrew N Redington - Lee N Benson - Christopher Macg

Source: https://link.springer.com/article/10.1186/1532-429X-13-43







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