Pressure constrained mitral annular dysfunction determines severity of regurgitation in Barlow's disease – a 3D echocardiographic study. (25th November 2020)

• Record Type: Journal Article
• Authors: Dumont, K.A; Persson, R; Kvitting, J.P; Lundblad, R; Haaverstad, R; Fiane, A; Urheim, S
• Is Part Of: European heart journal. Volume 41:(2020)Supplement 2
• Publication Date: 2020-11-25
• Subjects: Valvular Heart Disease - Diagnostic Methods; Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/ehjci/ehaa946.1917
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Background: Barlow's disease provides both diagnostic and therapeutic challenges. The impact of systemic blood-pressure on severity of regurgitation is still unclear. Purpose: We hypothesized that mitral annulus behaves passively with enlargement during ventricular systole, and secondly, we tested the hypothesis that severity of regurgitation correlates to systemic blood-pressure (BP) of the patient. Methods: Ten patients with Barlow's disease were compared with 10 healthy controls. Brachial blood-pressure was measured according to guidelines. Transthoracic 3D echo was obtained from an apical view (38.6±8.2 frames per second). Data was analyzed using a holographic display. We measured commissure width (CW), septallateral length (SL) and mitral annular surface area throughout the cardiac cycle. Aortic flow ejection time was derived from continuous Doppler across the aortic valve. Timing of aortic valve closure was visually assessed by 3D echo. Onset and end of mitral regurgitation was derived from continuous wave Doppler of transmitral flow. Results: Systolic BP in controls and patients were 122±5 and 133±12 mmHg, respectively (p<0.05). Enddiastolic volume was 87±7 ml/m 2 (controls) and 100±14 ml/m 2 (Barlow), p<0.02. Left ventricular EF in controls and patients were 59±5 and 62±5%, respectively, p=NS. Barlow patients had moderate or severe late systolic regurgitation with mean regurgitation volume of 51±18 ml. Annular surface area, CW and SL behaved passively with enlargement during ventricular systole (Figure 1). Peak systolic surface area, CW and SL in healthy controls and Barlow patients were 8.7±0.5 vs 20.7±3.2 cm 2 (p<0.001), 30.1±1.5 vs 49.5±4.9 mm (p<0.001) and 30.9±1.5 vs 44.9±3.3 mm (p<0.001). Peak annular surface area and regurgitation volume in patients showed a positive correlation with systolic BP (y = 0.156x − 0.077, r=0.60 and y = 1.136x − 99.7, r=0.80, respectively). Conclusions: We have demonstrated pressure constrained mitral annular dysfunction in Barlow's disease, indicating that systemic blood pressure may modify the severity of regurgitation. The study provides novel insights into mechanisms of mitral regurgitation and potential therapeutic actions in the future. Funding Acknowledgement: Type of funding source: Foundation. Main funding source(s): Grieg Foundation