P6.6 NITROGLYCERIN IMPROVES SYSTOLIC MYOCARDIAL EFFICIENCY

DOI

10.1016/j.artres.2015.10.290How to use a DOI?

Abstract

Introduction: Nitroglycerin (NTG) has a particularly marked action to reduce augmentation pressure (cAP), attributed to a reduction in timing or amplitude of pressure wave reflection. However, a recent study suggests that cAP is determined in large part by ventricular contraction/relaxation dynamics. We examined whether the reduction in cAP induced by NTG is associated with a change in left ventricular (LV) systolic function.

Methods: We estimated myocardial wall stress from transthoracic echocardiographic imaging of the LV and LV pressure estimated from carotid tonometry during systole. Eighteen subjects aged 43.0±11.9 (mean ± SD) years were studied before and 7-12 min after NTG (400 μg sublingually). Carotid pressure calibrated by mean and diastolic blood pressure was used to calculate time-varying LV wall stress from endocardial and epicardial volumes obtained from wall tracking analysis. Tissue Doppler Imaging (TDI) S wave (a measure of LV systolic function) was measured at the basal mitral annulus from an echocardiographic 4-chamber view.

Results: NTG decreased cAP from 16.3±3.6 to 4.5±2.9mmHg (means±SEM, P<0.0001) and central systolic blood pressure decreased by a similar amount. Time to peak MWS decreased from 115.9±10.9 to 86.8±4.6ms (P=0.024). This difference persisted after adjustment for change in heart rate and blood pressure (P=0.017). TDI S wave increased from 3.1±0.3 to 4.0±0.4cm/s (P=0.017). By contrast, NTG had no significant effect on ejection fraction or stroke volume.

Conclusion: NTG reduces cAP and improves the efficiency of myocardial contraction with a reduction in time to peak MWS.

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TY  - JOUR
AU  - Haotian Gu*
AU  - Henry Fok
AU  - Benyu Jiang
AU  - Manish Sinha
AU  - John Simpson
AU  - Phil Chowienczyk
PY  - 2015
DA  - 2015/11/23
TI  - P6.6 NITROGLYCERIN IMPROVES SYSTOLIC MYOCARDIAL EFFICIENCY
JO  - Artery Research
SP  - 26
EP  - 26
VL  - 12
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2015.10.290
DO  - 10.1016/j.artres.2015.10.290
ID  - Gu*2015
ER  -